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Molecular-level analyses of breast carcinogenesis benefit from vivo disease models. Estrogen receptor 1 (Esr1) and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) overexpression targeted to mammary epithelial cells in genetically engineered mouse models induces largely similar rates of proliferative mammary disease in prereproductive senescent mice. Herein, with natural reproductive senescence, Esr1 overexpression compared with CYP19A1 overexpression resulted in significantly higher rates of preneoplasia and cancer. Before reproductive senescence, Esr1, but not CYP19A1, overexpressing mice are tamoxifen resistant. However, during reproductive senescence, Esr1 mice exhibited responsiveness. Both Esr1 and CYP19A1 are responsive to letrozole before and after reproductive senescence. Gene Set Enrichment Analyses of RNA-sequencing data sets showed that higher disease rates in Esr1 mice were accompanied by significantly higher expression of cell proliferation genes, including members of prognostic platforms for women with early-stage hormone receptor-positive disease. Tamoxifen and letrozole exposure induced down-regulation of these genes and resolved differences between the two models. Both Esr1 and CYP19A1 overexpression induced abnormal developmental patterns of pregnancy-like gene expression. This resolved with progression through reproductive senescence in CYP19A1 mice, but was more persistent in Esr1 mice, resolving only with tamoxifen and letrozole exposure. In summary, genetically engineered mouse models of Esr1 and CYP19A1 overexpression revealed a diversion of disease processes resulting from the two distinct molecular pathophysiological mammary gland-targeted intrusions into estrogen signaling during reproductive senescence.

The increased survival achieved with surgery and cancer treatments for breast cancer has led to a growing concern about fertility in young women, adversely affecting quality of life outcomes. Th e potential loss of fertility not only has a psychological but can also affect patients' treatment adherence or decisions, such as selection of treatments associated with a lower risk of infertility despite inferior outcomes. Our objective is to provide an overview of current knowledge about how systemic cancer treatments could impact the future fertility of breast cancer survivors The main hypothesis of how chemotherapy produce damage to the ovaries is a direct damage to the DNA of the oocytes, resulting in the activation of apoptosis and / or autophagy-related pathways. Alkylating agents as cyclophosphamide are the chemotherapeutic agents that are associated with the highest risk of gonadotoxicity; however, breast cancer patients are usually given combinations of chemotherapy drugs. Conversely, endocrine therapy, such as tamoxifen, does not appear to have a permanent effect on fertility but long-term use could lower oocyte quality due to patient aging. There is still not enough evidence about the effect on ovarian reserve for many biological therapies and for new drugs being used in the non-metastatic setting, and further research in this area is needed. Members of multidisciplinary teams in breast cancer should understand the impact on fertility of cancer treatments and the importance of an early referral of premenopausal patients to specialists in reproductive medicine to discuss all possible fertility preservation strategies.

Connexins (Cxs) are a group of gap junction proteins involved in the direct exchange of small molecules between neighboring cells. Information concerning the expression and regulation of Cxs in the chicken oviduct is lacking, but likely has potential implications for functioning of the oviduct and the quality of the egg laid by commercially used hens. The present study was designed to examine whether selected Cxs are present in the chicken oviduct and, if so, whether expression of the most abundant Cx changes following tamoxifen (TMX; estrogen receptor modulator) treatment. Hy-Line Brown laying hens were injected (s.c.) daily with a vehicle (n = 6) or with TMX (n = 6), at a dose of 6 mg/kg of body weight for 7 days until complete cessation of egg laying by TMX-treated hens. All oviductal segments (infundibulum, magnum, isthmus, shell gland, and vagina) were collected from hens on day 8 of the experiment. First, the gene expression of GJA1 (i.e. Cx43 protein), GJA4 (Cx39), GJB1 (Cx32), and GJD2 (Cx36) was investigated by real-time PCR in tissues of control birds. The results demonstrated gene- and oviductal segment-dependent expression of GJB1, GJD2, GJA4, and GJA1 mRNA. Since the GJA1 transcript was the most abundant in all oviductal parts, subsequently, the Cx43 expression and localization were examined in the oviduct of all hens. The relative expression of GJA1 mRNA in control hens was highest in the infundibulum and vagina and lowest in the magnum. The pattern of Cx43 protein abundance evaluated by Western blot was similar to that of mRNA. Treatment of hens with TMX decreased the GJA1 mRNA levels in the magnum and isthmus, and Cx43 protein abundances were reduced in the isthmus and vagina. Immunofluorescence demonstrated cell- and segment-dependent localization of Cx43 protein in the oviductal wall; the most intense immunoreactivity was observed in the muscle cells of the shell gland and vagina. In TMX-treated hens, the immunoreactivity for Cx43 in all oviductal segments was slightly reduced and had a different signal pattern compared with control chickens. These results suggest that Cx43 likely takes part in the regulation of oviduct functioning, especially in the coordination of muscle contraction required for egg transport and oviposition. In addition, the results suggest a contribution of estrogen in the regulation of Cx43 expression and/or fates in the chicken oviduct. New insights into the expression and regulation of Cxs in the hen oviduct, indicating their potential involvement in the mechanisms of egg formation and transport that may affect poultry production, were obtained in this study.

Breast cancer (BC) cell de-sensitization to Tamoxifen (TAM) or other selective estrogen receptor (ER) modulators (SERM) is a complex process associated with BC heterogeneity and the transformation of ER signalling. The most influential resistance-related mechanisms include modifications in ER expression and gene regulation patterns. During TAM/SERM treatment, epigenetic mechanisms can effectively silence ER expression and facilitate the development of endocrine resistance. ER status is efficiently regulated by specific epigenetic tools including hypermethylation of CpG islands within ER promoters, increased histone deacetylase activity in the ER promoter, and/or translational repression by miRNAs. Over-methylation of the ER α gene (ESR1) promoter by DNA methyltransferases was associated with poor prognosis and indicated the development of resistance. Moreover, BC progression and spreading were marked by transformed chromatin remodelling, post-translational histone modifications, and expression of specific miRNAs and/or long non-coding RNAs. Therefore, targeted inhibition of histone acetyltransferases (e.g. MYST3), deacetylases (e.g. HDAC1), and/or demethylases (e.g. lysine-specific demethylase LSD1) was shown to recover and increase BC sensitivity to anti-estrogens. Indicated as a powerful molecular instrument, the administration of epigenetic drugs can regain ER expression along with the activation of tumour suppressor genes, which can in turn prevent selection of resistant cells and cancer stem cell survival. This review examines recent advances in the epigenetic regulation of endocrine drug resistance and evaluates novel anti-resistance strategies. Underlying molecular mechanisms of epigenetic regulation will be discussed, emphasising the utilization of epigenetic enzymes and their inhibitors to re-program irresponsive BCs.

Background: Between 1982 and 1990 the Danish Breast Cancer Cooperative Group (DBCG) conducted a randomized trial in high-risk pre- and postmenopausal (

Molecular tests predicting the risk of distant recurrence (DR) can be used to assist therapy decision-making in oestrogen receptor-positive (ER+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer patients after considerations of standard clinical markers. The Oncotype DX Recurrence Score (RS) is a widespread tool used for this purpose. Here, we compared the RS with the StemPrintER Risk Score (SPRS), a novel genomic predictor with a unique biological basis in its ability to measure the expression of cancer stemness genes.We benchmarked the SPRS vs. RS, alone or in combination with clinicopathological variables expressed by the Clinical Treatment Score (CTS), for the prognostication of DR in a retrospective cohort of 776 postmenopausal patients with ER+/HER2-breast cancer enrolled in the translational arm of the randomised Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial. Likelihood ratio (LR) with χIn all patients, the SPRS provided significantly more prognostic information than the RS for ten-year DR prognostication (C-index = 0.688, LR-χIn postmenopausal ER+/HER2- breast cancer patients, SPRS provided more prognostic information than RS for DR when used alone or in combination with the CTS. The SPRS could therefore potentially identify high-risk patients, who might benefit from aggressive treatments, from low-risk patients who might safely avoid adjuvant chemotherapy or prolongation of endocrine therapy.

Made available in DSpace on 2022-04-29T08:38:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-01 Tamoxifen, a selective non-steroidal estrogen receptor modulator, is the standard adjuvant endocrine treatment for breast cancer. Since information on the risk of using tamoxifen during pregnancy is still scarce, this study evaluated whether the in utero and lactational treatment with this drug could compromise reproductive and behavioural parameters in male offspring. Pregnant Wistar rats were exposed to three doses of tamoxifen (0.12; 0.6; 3 μg/kg), by gavage, from gestational day 15 to lactational day 20. Tamoxifen exposure did not alter the anogenital distance in the male offspring; however, there was a significant increase in the body weight in the 0.12 μg/kg dose and a decrease in the 0.6 μg/kg dose. The male offspring treated with the highest dose exhibited a delay in the onset of puberty, evidenced by an increase in the age of preputial separation. Regarding sperm parameters, there was an increase in the sperm count in the cauda epididymis in the intermediate and highest dose groups, in addition to an increase in the number of static sperm and a decrease in the progressive sperm in the same groups. Moreover, an increase in the number of hyperplasia of the epithelial clear cells was observed in the epididymis. In conclusion, the present study demonstrated that maternal exposure to tamoxifen compromised the installation of puberty of the male offspring and the maturation of the epididymis, affecting sperm storage and motility in the adult life. Faculty of Health Sciences Universidade Federal da Grande Dourados – UFGD Departamet of Structural and Functional Biology Institute of Biosciences of Botucatu Universidade Estadual Paulista – UNESP Center of Toxicological Assistance (CEATOX) Institute of Biosciences of Botucatu Univ. Estadual Paulista – Botucatu (UNESP) Departamet of Structural and Functional Biology Institute of Biosciences of Botucatu Universidade Estadual Paulista – UNESP Center of Toxicological Assistance (CEATOX) Institute of Biosciences of Botucatu Univ. Estadual Paulista – Botucatu (UNESP)

Preclinical studies have demonstrated a complex cross-talk between Notch and estrogen signaling in ERα-positive breast cancer. Gamma-secretase inhibitors (GSIs) are investigational agents that block the cleavage and activation of Notch receptors. In animal models of endocrine-resistant breast cancer, combinations of tamoxifen and GSIs produce additive or synergistic efficacy, while decreasing the intestinal toxicity of GSIs. However, results of a clinical trial of a GSI-endocrine therapy combination in the metastatic setting have not been published to date, nor had the safety of such combinations been investigated with longer term treatment. We conducted a phase 1b dose escalation trial (NCT01149356) of GSI RO4929097 with exemestane in patients with ERα+, metastatic breast cancer (MBC) Study objectives: to determine the safety, tolerability and maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of RO4929097 when administered in combination with exemestane in patients with estrogen receptor positive metastatic breast cancer Results: We enrolled 15 patients with MBC. Of 14 evaluable patients, one had a partial response, 6 had stable disease and 7 progressive disease. Twenty % of patients had stable disease for ≥ 6 months. Common toxicities included nausea (73.3%), anorexia (60%), hyperglycemia (53.3%), hypophosphatemia (46.7%), fatigue (66.7%) and cough (33.0%). Grade 3 toxicities were uncommon, and included hypophosphatemia (13%) and rash (6.3%). Rash was the only DLT observed at 140 mg/d. Results suggest a possible recommended phase 2 dose of 90 mg/d. Ten patients with evaluable archival tissue showed expression of PKCα, which correlated with expression of Notch4. Mammospheres from a PKCα-expressing, endocrine-resistant T47D cell line were inhibited by a GSI-fulvestrant combination Conclusions: Our data indicate that combinations including endocrine therapy and Notch inhibitors deserve further investigation in endocrine-resistant ERα-positive breast cancer.

The preservation of fertility in women of childbearing age with breast cancer is challenging because the time for ovarian stimulation is restricted and only a limited number of oocytes can be retrieved before gonadotoxic therapies. The aim of this meta-analysis was to evaluate the fertility preservation outcomes after ovarian stimulation with various protocols in women with breast cancer. PubMed, Embase and the Cochrane Library were searched. Twenty-two studies comparing the outcomes of women with breast cancer receiving random-start ovarian stimulation or conventional protocol; single or double ovarian stimulation cycles; and coadministration of aromatase inhibitors or tamoxifen were included. Random-start ovarian stimulation resulted in a comparable number of retrieved oocytes to the conventional protocol. Two ovarian stimulation cycles had significantly higher numbers of total retrieved oocytes than one cycle (mean difference 7.91, 95% confidence interval [CI] 3.42 to 12.40). Coadministration of letrozole and tamoxifen showed similar results for retrieved oocytes to those without. A significantly lower peak serum oestradiol concentration was observed in letrozole-based groups than in letrozole-free groups (mean difference -1.22; 95% CI -1.42 to -1.02). In conclusion, this study indicated that implementing random-start protocols to shorten the duration of waiting for ovarian stimulation, applying two ovarian stimulation cycles, and coadministration of letrozole can lead to more desirable outcomes.

The transforming growth factor beta (TGF-β) signaling pathway plays complex role in the regulation of cell proliferation, apoptosis and differentiation in breast cancer. TGF-β activation can lead to multiple cellular responses mediating the drug resistance evolution, including the resistance to antiestrogens. Tamoxifen is the most commonly prescribed antiestrogen that functionally involved in regulation of TGF-β activity. In this review, we focus on the role of TGF-β signaling in the mechanisms of tamoxifen resistance, including its interaction with estrogen receptors alfa (ERα) pathway and breast cancer stem cells (BCSCs). We summarize the current reported data regarding TGF-β signaling components as markers of tamoxifen resistance and review current approaches to overcoming tamoxifen resistance based on studies of TGF-β signaling.

Background The use of endocrine therapy for early-stage breast cancer, particularly aromatase inhibitor therapy has been associated with an increased risk of osteoporosis and fracture in clinical trials. We sought to validate this observation in real-world practice. Methods We used health administrative data collected from post-menopausal women (aged ≥66 years) who were diagnosed with breast cancer and started on adjuvant endocrine therapy from 2005 to 2012. Patients were classified by use of either an aromatase inhibitor or tamoxifen and followed until 2017 for a new diagnosis of an osteoporotic fracture. A multivariable analysis using a Cox proportional hazards model was adjusting for age, medical co-morbidities, medication use and duration of endocrine therapy. Results We identified 12,077 patients of whom 73% were treated with an aromatase inhibitor as compared to 27% with tamoxifen. Our multivariable analysis did not demonstrate any significant difference in the rate of osteoporotic fracture between patients treated with an aromatase inhibitor when compared with tamoxifen [Hazard ratio (HR) = 1.09; 95% confidence interval (CI) = 0.96–1.23, p-value = 0.18]. The 5-year rate of osteoporotic fracture for patients treated with either an aromatase inhibitor or tamoxifen was 7.5% and 6.9%, respectively. A completed sensitivity analysis did observe a decreased risk of fracture associated with tamoxifen usage over time. Conclusion We could not detect a significant difference in the rate of osteoporotic fracture among patients treated with an aromatase inhibitor versus tamoxifen. Nonetheless, the risk with tamoxifen was numerically lower and significantly decreased when accounting for total duration of endocrine therapy., Highlights • Our real-world study investigated the osteoporotic fracture risk among early-stage post-menopausal breast cancer patients. • No significant difference in fracture rates was observed among patients treated with aromatase inhibitors versus tamoxifen. • The risk of osteoporotic fracture decreased with tamoxifen usage over time. • Bone health should be carefully monitored and optimized among breast cancer patients recieving endocrine therapy.

The cardiac conduction system is a network of heterogeneous cell population that initiates and propagates electric excitations in the myocardium. Purkinje fibers, a network of specialized myocardial cells, comprise the distal end of the conduction system in the ventricles. The developmental origins of Purkinje fibers and their roles during cardiac physiology and arrhythmia have been reported. However, it is not clear if they play a role during ischemic injury and heart regeneration. Here we introduce a novel tamoxifen-inducible Cre allele that specifically labels a broad range of components in the cardiac conduction system while excludes other cardiac cell types and vital organs. Using this new allele, we investigated the cellular and molecular response of Purkinje fibers to myocardial injury. In a neonatal mouse myocardial infarction model, we observed significant increase in Purkinje cell number in regenerating myocardium. RNA-Seq analysis using laser-captured Purkinje fibers showed a unique transcriptomic response to myocardial infarction. Our finds suggest a novel role of cardiac Purkinje fibers in heart injury.

BACKGROUND Late recurrences in postmenopausal women with hormone receptor-positive breast cancers remain an important challenge. Avoidance or delayed development of resistance represents the main objective in extended endocrine therapy (ET). In animal models, resistance was reversed with restoration of circulating estrogen levels during interruption of letrozole treatment. This phase III, randomized, open-label Study of Letrozole Extension (SOLE) studied the effect of extended intermittent letrozole treatment in comparison with continuous letrozole. In parallel, the SOLE estrogen substudy (SOLE-EST) analyzed the levels of estrogen during the interruption of treatment. PATIENTS AND METHODS SOLE enrolled 4884 postmenopausal women with hormone receptor-positive, lymph node-positive, operable breast cancer between December 2007 and October 2012 and among them, 104 patients were enrolled in SOLE-EST. They must have undergone local treatment and have completed 4-6 years of adjuvant ET. Patients were randomized between continuous letrozole (2.5 mg/day orally for 5 years) and intermittent letrozole treatment (2.5 mg/day for 9 months followed by a 3-month interruption in years 1-4 and then 2.5 mg/day during all of year 5). RESULTS Intention-to-treat population included 4851 women in SOLE (n��= 2425 in the intermittent and n��= 2426 in the continuous letrozole groups) and 103 women in SOLE-EST (n��= 78 in the intermittent and n��= 25 in the continuous letrozole groups). After a median follow-up of 84 months, 7-year disease-free survival (DFS) was 81.4% in the intermittent group and 81.5% in the continuous group (hazard ratio: 1.03, 95% confidence interval: 0.91-1.17). Reported adverse events were similar in both groups. Circulating estrogen recovery was demonstrated within 6 weeks after the stop of letrozole treatment. CONCLUSIONS Extended adjuvant ET by intermittent administration of letrozole did not improve DFS compared with continuous use, despite the recovery of circulating estrogen levels. The similar DFS coupled with previously reported quality-of-life advantages suggest intermittent extended treatment is a valid option for patients who require or prefer a treatment interruption.

Despite new combination therapies improving survival of breast cancer patients with estrogen receptor α (ER+) tumors, the molecular mechanisms for endocrine-resistant disease remain unresolved. Previously we demonstrated that expression of the RNA binding protein and N6-methyladenosine (m6A) reader HNRNPA2B1 (A2B1) is higher in LCC9 and LY2 tamoxifen (TAM)-resistant ERα breast cancer cells relative to parental TAM-sensitive MCF-7 cells. Here we report that A2B1 protein expression is higher in breast tumors than paired normal breast tissue. Modest stable overexpression of A2B1 in MCF-7 cells (MCF-7-A2B1 cells) resulted in TAM- and fulvestrant- resistance whereas knockdown of A2B1 in LCC9 and LY2 cells restored TAM and fulvestrant, endocrine-sensitivity. MCF-7-A2B1 cells gained hallmarks of TAM-resistant metastatic behavior: increased migration and invasion, clonogenicity, and soft agar colony size, which were attenuated by A2B1 knockdown in MCF-7-A2B1 and the TAM-resistant LCC9 and LY2 cells. MCF-7-A2B1, LCC9, and LY2 cells have a higher proportion of CD44+/CD24-/low cancer stem cells (CSC) compared to MCF-7 cells. MCF-7-A2B1 cells have increased ERα and reduced miR-222-3p that targets ERα. Like LCC9 cells, MCF-7-A2B1 have activated AKT and MAPK that depend on A2B1 expression and are growth inhibited by inhibitors of these pathways. These data support that targeting A2B1 could provide a complimentary therapeutic approach to reduce acquired endocrine resistance.

The trade-offs between innovation and pharmaceutical access are central to the policy debate on drug pricing. High prices may limit access, result in medication underuse, and negatively affect outcomes. Generic drugs make treatments more affordable. Prior research measured access as utilization without a defined population that should receive certain drugs, it is unknown whether generic entry reduces underuse and thus improves access.To measure changes in access (use, timeliness) with the introduction of three generic aromatase inhibitors (AIs, oral breast cancer drugs) between June 2010 and June 2011.This population-based study included 93,650 older (65+) women diagnosed with hormone receptor-positive breast cancer between 2007 and 2013 in the Surveillance, Epidemiology and End Results-Medicare linked database. We examined changes in access with generic entry for initiation of any adjuvant hormonal therapy drug (AIs or tamoxifen) within one year of diagnosis, time from diagnosis to initiation, and choice of initial therapy.Among 93,650 newly diagnosed breast cancer cases, 67,372 initiated one of the four drugs. With generic entry, initiation rates increased from 69.5% to 74.3%, but non-initiation remained high (up to 25.7%). After controlling for demographics, clinical factors, and insurance coverage, the probability of initiation increased by 4.6 percentage points (P 0.001, 95%CI: [4.1,5.2]) after generic entry. With generic entry, estimated time to initiation decreased by 0.3 months (P 0.001, 95%CI: [0.2,0.3]) from 4.1 months, and the probability of choosing AIs over tamoxifen increased by 5.9 percentage points (P 0.001, 95%CI: [5.3,6.5]). Patterns did not substantially differ by level of cost-sharing.Generic entry of AIs was associated with increased probability of receiving recommended treatments, timeliness of treatment, and the probability of receiving clinically preferred treatments. Price changes with generic entry only partially explained these improvements. High non-initiation rates after generic entry suggest prices are not the sole determinant of access.

We investigated whether our convolutional neural network-based breast cancer risk model is modifiable by testing it on women who had undergone risk-reducing treatment with known chemoprevention agents. Compared with baseline, significantly more women in the treatment group had a decrease in the breast cancer risk score (P < .01), indicating that our convolutional neural network risk model is modifiable with potential utility in assessing the efficacy of chemoprevention strategies. INTRODUCTION: We investigated whether our convolutional neural network (CNN)-based breast cancer risk model is modifiable by testing it on women who had undergone risk-reducing chemoprevention treatment. MATERIALS AND METHODS: We conducted a retrospective cohort study of patients diagnosed with atypical hyperplasia, lobular carcinoma in situ, or ductal carcinoma in situ at our institution from 2007 to 2015. The clinical characteristics, chemoprevention use, and mammography images were extracted from the electronic health records. We classified two groups according to chemoprevention use. Mammograms were performed at baseline and subsequent follow-up evaluations for input to our CNN risk model. The 2 chemoprevention groups were compared for the risk score change from baseline to follow-up. The change categories included stayed high risk, stayed low risk, increased from low to high risk, and decreased from high to low risk. Unordered polytomous regression models were used for statistical analysis, with P < .05 considered statistically significant. RESULTS: Of 541 patients, 184 (34%) had undergone chemoprevention treatment (group 1) and 357 (66%) had not (group 2). Using our CNN breast cancer risk score, significantly more women in group 1 had shown a decrease in breast cancer risk compared with group 2 (33.7% vs. 22.9%; P < .01). Significantly fewer women in group 1 had an increase in breast cancer risk compared with group 2 (11.4% vs. 20.2%; P < .01). On multivariate analysis, an increase in breast cancer risk predicted by our model correlated negatively with the use of chemoprevention treatment (P = .02). CONCLUSIONS: Our CNN-based breast cancer risk score is modifiable with potential utility in assessing the efficacy of known chemoprevention agents and testing new chemoprevention strategies.

Selective estrogen receptor modulators (SERMs) are a class of compounds that bind to estrogen receptors (ERs) and possess estrogen agonist or antagonist actions in different tissues. As such, they are widely used drugs. For instance, tamoxifen, the most prescribed SERM, is used to treat ERα-positive breast cancer. Aside from their therapeutic targets, SERMs have the capacity to broadly affect cellular cholesterol metabolism and handling, mainly through ER-independent mechanisms. Cholesterol metabolism reprogramming is crucial to meet the needs of cancer cells, and different key processes involved in cholesterol homeostasis have been associated with cancer progression. Therefore, the effects of SERMs on cholesterol homeostasis may be relevant to carcinogenesis, either by contributing to the anticancer efficacy of these compounds or, conversely, by promoting resistance to treatment. Understanding these aspects of SERMs actions could help to design more efficacious therapies. Herein we review the effects of SERMs on cellular cholesterol metabolism and handling and discuss their potential in anticancer pharmacology.

Breast cancer arises as a result of multiple interactions between environmental and genetic factors. Conventionally, breast cancer is treated based on histopathological and clinical features. DNA technologies like the human genome microarray are now partially integrated into clinical practice and are used for developing new “personalized medicines” and “pharmacogenetics” for improving the efficiency and safety of cancer medications. We investigated the effects of four established therapies—for ER+ ductal breast cancer—on the differential gene expression. The therapies included single agent tamoxifen, two-agent docetaxel and capecitabine, or combined three-agents CAF (cyclophosphamide, doxorubicin, and fluorouracil) and CMF (cyclophosphamide, methotrexate, and fluorouracil). Genevestigator 8.1.0 was used to compare five datasets from patients with infiltrating ductal carcinoma, untreated or treated with selected drugs, to those from the healthy control. We identified 74 differentially expressed genes involved in three pathways, i.e., apoptosis (extrinsic and intrinsic), oxidative signaling, and PI3K/Akt signaling. The treatments affected the expression of apoptotic genes (TNFRSF10B [TRAIL], FAS, CASP3/6/7/8, PMAIP1 [NOXA], BNIP3L, BNIP3, BCL2A1, and BCL2), the oxidative stress-related genes (NOX4, XDH, MAOA, GSR, GPX3, and SOD3), and the PI3K/Akt pathway gene (ERBB2 [HER2]). Breast cancer treatments are complex with varying drug responses and efficacy among patients. This necessitates identifying novel biomarkers for predicting the drug response, using available data and new technologies. GSR, NOX4, CASP3, and ERBB2 are potential biomarkers for predicting the treatment response in primary ER+ ductal breast carcinoma.

Progesterone (P4) and estradiol (E2) have been shown to stimulate and regulate breast cancer proliferation via classical nuclear receptor signaling through progesterone receptor (PR) and estrogen receptor α (ERα), respectively. However, the basis of communication between PR/ERα and membrane receptors remains largely unknown. Here, we aim to identify classical and nonclassical endocrine signaling mechanisms that can alter cell proliferation through a possible crosstalk between PR, ERα, and progesterone receptor membrane component 1 (PGRMC1), a membrane receptor frequently observed in breast cancer cells. While P4 and E2 treatment increased cell proliferation of ER+/PR+/PGRMC1 overexpressing breast cancer cells, silencing ERα and PR or treatment with selective estrogen receptor modulator (SERM) tamoxifen, or (PR-antagonist) RU-486 decreased cell proliferation. All four treatments rapidly altered PGRMC1 mRNA levels and protein expression. Furthermore, P4 and E2 treatments rapidly activated EGFR a known interacting partner of PGRMC1 and its downstream signaling. Interestingly, downregulation of ERα by tamoxifen and ERα silencing decreased the expression levels of PGRMC1 with no repercussions to PR expression. Strikingly PGRMC1 silencing decreased ERα expression irrespective of PR. METABRIC and TCGA datasets further demonstrated that PGRMC1 expression was comparable to that of ERα in Luminal A and B breast cancers. Targeting of PR, ERα, and PGRMC1 confirmed that a crosstalk between classical and nonclassical signaling mechanisms exists in ER+ breast cancer cells that could enhance the growth of ER+/PR+/PGRMC1 overexpressing tumors.

Increased implementation of proven prevention strategies is required to combat rising breast cancer incidence. We assessed use of risk reducing medication (RRMed) by Australian women at elevated breast cancer risk. Only 2.4% had ever used RRMed. Higher breast cancer risk was statistically significantly associated with use of RRMed (OR 1.82, 95%CI: 1.08–3.07, p = 0.02 for ≥30% lifetime risk compared with 16%–29% lifetime risk), but parity, education level and family history of breast cancer were not. Breast cancer prevention medications are underutilised. Efforts are needed to incorporate breast cancer risk assessment and risk management discussions into routine health assessments for women., Highlights • Risk-reducing medication is infrequently used by Australian women at increased risk of breast cancer. • Higher breast cancer risk is associated with greater uptake of risk reducing medication, but not with adherence. • Routine breast cancer risk assessment may increase risk reducing medication use.

Introduction Hormonal therapy with tamoxifen and aromatase inhibitors reduces breast cancer recurrence and mortality but represents a risk factor for thromboembolic events. Therefore, most surgeons discontinue hormonal agents before microvascular surgery and for a variable period thereafter. There are no guidelines regarding when therapy should be stopped (preoperatively) or when it should be resumed (post-operatively). We, therefore, audited our hospital practice with the objective of making recommendations for microvascular breast reconstruction patients. Patients and methods A review was performed of all free flap breast reconstructions between 2014 and 2019. Patients were classified according to hormone medication status at operation. Timings of drug cessation and recommencement were recorded. Thrombotic events, namely flap microvascular thrombosis, deep vein thrombosis, superficial vein thrombosis and pulmonary embolism, were compared. Results A total of 240 patients had 275 free flaps over five years with 36 receiving hormone therapy within one month prior to surgery, which was discontinued 8.5 days (range: 0–28 days) before surgery. Intraoperative microvascular thromboses (HT 2.0%, NHT 0%, and p = 0.869) and post-operative microvascular complications/flap re-explorations (HT 6.6%, NHT 0%, and p = 0.234) were comparable between the two groups. Systemic venous thromboembolic events were also similar (HT 8.3%, NHT 6.1%, and p = 0.893). Age, BMI, smoking status and preoperative chemotherapy did not influence the incidence of thrombotic complications. Conclusion Hormone therapy did not significantly increase the risk of thromboembolic events. Despite the widespread practice of withholding it for 2 weeks prior to reconstructive surgery, this study does not support such practice being beneficial in terms of thromboembolic events and flap viability. Large-scale trials are needed to establish definitive protocols.

Breast cancer remains the most common cancer in women in the United States. For certain women at high risk for breast cancer, endocrine therapy (ET) can greatly decrease the risk. Tools such as the Breast Cancer Risk Assessment Tool (or Gail Model) and the International Breast Cancer Intervention Study risk calculator are available to help identify women at increased risk for breast cancer. Physician awareness of family history, reproductive and lifestyle factors, dense breast tissue, and history of benign proliferative breast disease are important when identifying high-risk women. The updated US Preventive Services Task Force and American Society of Clinical Oncology guidelines encourage primary care providers to identify at-risk women and offer risk-reducing medications. Among the various ETs, which include tamoxifen, raloxifene, anastrozole, and exemestane, tamoxifen is the only one available for premenopausal women aged 35 years and older. A shared decision-making process should be used to increase the usage of ET and must be individualized. This individualized approach must account for each woman's medical history and weigh the benefits and risks of ET in combination with the personal values of the patient.

Purpose In the randomised phase II LEO trial, we investigated the effect of adding everolimus (EVE) to letrozole (LET) in ovarian-suppressed premenopausal women with hormone receptor-positive (HR+), HER2-negative (HER2–) recurrent/metastatic breast cancer. Methods Patients with progression or prior exposure to tamoxifen with or without gonadotropin-releasing hormone agonists, either sequentially or concurrently, in adjuvant or metastatic setting were randomly assigned (2:1) to the EVE arm (leuprorelin + LET + EVE) or the LET arm (leuprorelin + LET) until disease progression or unacceptable toxicity. The primary end-point was progression-free survival (PFS). Secondary end-points included overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR) and safety. Results Between January 2014 and October 2018, 137 patients were enrolled (median age, 44 years [range, 24–56]). Of them, 75% had endocrine-sensitive disease, and 61% had visceral metastasis. With the median follow-up of 32.4 months, the median PFS was 18.1 months in the EVE arm and 13.8 months in the LET arm (HR 0.73, P = 0.137). Among patients with visceral metastases, the median PFS was significantly longer in the EVE arm (16.4 versus 9.5 months, P = 0.048). The median OS was not reached in both arms. The CBR was significantly higher in the EVE arm (83% versus 62%, P = 0.010). The ORR was similar between the two arms. The most common grade 3/4 adverse events in the EVE arm were neutropenia, alanine aminotransferase elevation and anaemia. Conclusions EVE plus LET with ovarian-suppression resulted in longer PFS in tamoxifen-exposed HR+, HER2– metastatic breast cancer patients with visceral metastasis.

Summary Background Palbociclib added to endocrine therapy improves progression-free survival in hormone-receptor-positive, HER2-negative, metastatic breast cancer. The PALLAS trial aimed to investigate whether the addition of 2 years of palbociclib to adjuvant endocrine therapy improves invasive disease-free survival over endocrine therapy alone in patients with hormone-receptor-positive, HER2-negative, early-stage breast cancer. Methods PALLAS is an ongoing multicentre, open-label, randomised, phase 3 study that enrolled patients at 406 cancer centres in 21 countries worldwide with stage II–III histologically confirmed hormone-receptor-positive, HER2-negative breast cancer, within 12 months of initial diagnosis. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance score of 0 or 1. Patients were randomly assigned (1:1) in permuted blocks of random size (4 or 6), stratified by anatomic stage, previous chemotherapy, age, and geographical region, by use of central telephone-based and web-based interactive response technology, to receive either 2 years of palbociclib (125 mg orally once daily on days 1–21 of a 28-day cycle) with ongoing standard provider or patient-choice adjuvant endocrine therapy (tamoxifen or aromatase inhibitor, with or without concurrent luteinising hormone-releasing hormone agonist), or endocrine therapy alone, without masking. The primary endpoint of the study was invasive disease-free survival in the intention-to-treat population. Safety was assessed in all randomly assigned patients who started palbociclib or endocrine therapy. This report presents results from the second pre-planned interim analysis triggered on Jan 9, 2020, when 67% of the total number of expected invasive disease-free survival events had been observed. The trial is registered with ClinicalTrials.gov (NCT02513394) and EudraCT (2014-005181-30). Findings Between Sept 1, 2015, and Nov 30, 2018, 5760 patients were randomly assigned to receive palbociclib plus endocrine therapy (n=2883) or endocrine therapy alone (n=2877). At the time of the planned second interim analysis, at a median follow-up of 23·7 months (IQR 16·9–29·2), 170 of 2883 patients assigned to palbociclib plus endocrine therapy and 181 of 2877 assigned to endocrine therapy alone had invasive disease-free survival events. 3-year invasive disease-free survival was 88·2% (95% CI 85·2–90·6) for palbociclib plus endocrine therapy and 88·5% (85·8–90·7) for endocrine therapy alone (hazard ratio 0·93 [95% CI 0·76–1·15]; log-rank p=0·51). As the test statistic comparing invasive disease-free survival between groups crossed the prespecified futility boundary, the independent data monitoring committee recommended discontinuation of palbociclib in patients still receiving palbociclib and endocrine therapy. The most common grade 3–4 adverse events were neutropenia (1742 [61·3%] of 2840 patients on palbociclib and endocrine therapy vs 11 [0·3%] of 2903 on endocrine therapy alone), leucopenia (857 [30·2%] vs three [0·1%]), and fatigue (60 [2·1%] vs ten [0·3%]). Serious adverse events occurred in 351 (12·4%) of 2840 patients on palbociclib plus endocrine therapy versus 220 (7·6%) of 2903 patients on endocrine therapy alone. There were no treatment-related deaths. Interpretation At the planned second interim analysis, addition of 2 years of adjuvant palbociclib to adjuvant endocrine therapy did not improve invasive disease-free survival compared with adjuvant endocrine therapy alone. On the basis of these findings, this regimen cannot be recommended in the adjuvant setting. Long-term follow-up of the PALLAS population and correlative studies are ongoing. Funding Pfizer.

Despite intense research, breast cancer remains the leading cause of cancer-related death in women worldwide, being estrogen receptor-positive (ER+) the most common subtype. Nowadays, aromatase inhibitors (AIs), the selective estrogen receptor modulator (SERM) tamoxifen and the selective estrogen receptor down-regulator (SERD) fulvestrant are used as therapeutic options for ER+ breast cancer, since they interfere directly with the production of estrogens and with the activation of estrogen-dependent signaling pathways. Despite the success of these treatments, the occurrence of resistance limits their clinical efficacy, demanding the development of novel therapies. Recently, multi-target compounds emerged as promising therapeutic strategies for ER+ breast cancer, as they can potentially modulate several important targets simultaneously. In line with this, in this work, the anti-cancer properties and multi-target action of 1,1-Bis(4-hydroxyphenyl)-2-phenylbut-1-ene, tamoxifen bisphenol (1,1-BHPE), were evaluated in an ER+ breast cancer cell model (MCF-7aro cells). Molecular docking analysis predicted that 1,1-BHPE was able to bind to aromatase, ERα and ERβ. In vitro studies showed that, although it did not present anti-aromatase activity, 1,1-BHPE reduced aromatase protein levels and interfered with ERα and ERβ signaling pathways, acting as an ERα antagonist and inducing ERβ up-regulation. Through these mechanisms, 1,1-BHPE was able to impair breast cancer growth and induce apoptosis. This represents an important therapeutic advantage because the main players responsible for estrogen production and signaling are modulated by a single compound. To the best of our knowledge, this is the first study describing the anti-cancer properties of 1,1-BHPE as a multi-target compound specific for ER+ breast cancer.

Cleft palate is a common birth defect in mammals, which can be caused by genetic or environmental factors, or both. Decades have witnessed that many environmental exposures during gestation extremely increase the incidence of cleft palate. Tamoxifen (TAM), a widely-used drug in treating breast cancer, has been reported to be associated with craniofacial defects including micrognathia and cleft palate in humans. However, its exact effects on the developing palate remain unclear. Here we took advantage of a mouse model to explore how TAM affects palatal development at the molecular level. We showed that excess exposure of TAM in the early embryonic stages indeed leads to cleft palate in mice. RNA-sequencing results strongly suggest the involvement of mitogen-activated protein kinase (MAPK) signalling in TAM-induced cleft palate. Interestingly, in the anterior portion of the TAM-treated palatal shelf, phosphorylated (p)-AKT and p-ERK1/2 were activated but p-p38 was inhibited, while in the posterior palate, the p-AKT increased but the levels of p-p38 and p-JNK decreased. We conclude that excess TAM exposure causes cleft palate defects in mice by regulating MAPK pathways, which implicates the importance of tightly-regulated MAPK signalling in palatal development. This study provides a basis for further exploration of the molecular aetiology of cleft palate defects caused by environmental factors and, based on our results, we would give a serious warning regarding prescription of TAM and potential cleft palate defects in animal models involving the inducible Cre-LoxP system.

Introduction 16α-[18F]Fluoroestradiol (FES), a PET radiotracer for the estrogen receptor (ER) in breast cancer, was the first receptor-targeted PET radiotracer for oncology and is continuing to prove its value in clinical research, antiestrogen development, and breast cancer care. The story of its conception, design, evaluation and use in clinical studies parallels the evolution of the whole field of receptor-targeted radiotracers, one greatly influenced by the research and intellectual contributions of William C. Eckelman. Methods and results The development of methods for efficient production of fluorine-18, for conversion of [18F]fluoride ion into chemically reactive form, and for its rapid and efficient incorporation into suitable estrogen precursor molecules at high molar activity, were all methodological underpinnings required for the preparation of FES. FES binds to ER with very high affinity, and its in vivo uptake by ER-dependent target tissues in animal models was efficient and selective, findings that preceded its use for PET imaging in patients with breast cancer. Advances in knowledge and implications for patient care Comparisons between ER levels measured by FES-PET imaging of breast tumors with tissue-specimen ER quantification by IHC and other methods show that imaging provided improved prediction of benefit from endocrine therapies. Serial imaging of ER by FES-PET, before and after dosing patients with antiestrogens, is used to determine the efficacious dose for established antiestrogens and to facilitate clinical development of new ER antagonists. Beyond FES imaging, PET-based hormone challenge tests, which evaluate the functional status of ER by monitoring rapid changes in tumor metabolic or transcriptional activity after a brief estrogen challenge, provide highly sensitive and selective predictions of whether or not there will be a favorable response to endocrine therapies. There is sufficient interest in the clinical applications of FES that FDA approval is being sought for its wider use in breast cancer. Conclusions FES was the first PET probe for a receptor in cancer, and its development and clinical applications in breast cancer parallel the conceptual evolution of the whole field of receptor-binding radiotracers.

Approximately 70% of breast cancers are estrogen receptor (ER)-positive and treated with endocrine therapy. A commonly used treatment agent, tamoxifen, shows high efficacy for improving prognosis. However, approximately one-third of patients treated with tamoxifen develop resistance to this drug. Here, we investigated the function of general control non-derepressible 5 (GCN5) and its downstream effectors in tamoxifen-resistant (TamR) breast cancer. TamR-MCF7 breast cancer cells maintained high GCN5 levels due to its attenuated proteasomal degradation. GCN5 overexpression upregulated amplified in breast cancer 1 (AIB1) expression, resulting in decreased p53 stability and tamoxifen resistance. Conversely, the sensitivity of GCN5-AIB1-overexpressing MCF7 cells to tamoxifen was restored by forced p53 expression. An in vivo study demonstrated a positive correlation between GCN5 and AIB1 and their contribution to tamoxifen resistance. We concluded that GCN5 promotes AIB1 expression and tamoxifen resistance in breast cancer by reducing p53 levels, suggesting the utility of GCN5 and its downstream effectors as therapeutic targets to either prevent or overcome tamoxifen resistance in breast cancer.

Introduction Adherence to oral endocrine therapy (OET) reduces recurrence risk for hormone receptor (HR)-positive breast cancer (BC). Refill data accessed through electronic health records may provide objective assessment of OET adherence. Our goal was to (1) determine the feasibility of reviewing electronic health records for assessing OET adherence, (2) evaluate 6 months’ OET adherence in HR-positive BC patients, and (3) identify predictors of low adherence. Patients and Methods A single-center, retrospective study from May through December 2018 was conducted. Primary end point was adherance rate at 6 months. Chi-square and Student t tests were used to compare adherent and nonadherent groups. Multivariable logistic regression models were used to assess predictors of adherence. Results Of 492 patients, 338 patients were included in adherence analysis. Of 338 patients identified, 82% (n = 277) were adherent at 6 months. In the multivariable logistic model, race/ethnicity, type of endocrine therapy, and time on therapy were found to be significantly associated with adherence. Asian/non-Hispanic and white/Hispanic patients were less likely to be adherent compared to white/non-Hispanics (Asian/non-Hispanic: odds ratio [OR], 0.3; 95% confidence interval [CI], 0.11-0.82; white/Hispanic: OR, 0.27; 95% CI, 0.11-0.64). Patients prescribed aromatase inhibitors were more likely to be adherent compared to patients prescribed tamoxifen (OR, 2.06; 95% CI, 1.02-4.14). Last, patients prescribed OET for 3 to 5 years had lower adherence compared to patients given OET for 2 years or less (OR, 0.29; 95% CI, 0.09-0.91). Conclusion Accessing refill data through electronic health records was found to be feasible. Tamoxifen therapy, Asian/non-Hispanic and white/Hispanic origin, and longer time on therapy predicted nonadherence in our patients.

The evolving dynamics of drug resistance due to tumor heterogeneity often creates impediments to traditional therapies making it a challenging issue for cancer cure. Breast cancer often faces challenges of current therapeutic interventions owing to its multiple complexities and high drug resistivity， for example against drugs like trastuzumab and tamoxifen. Drug resistance in the majority of breast cancer is often aided by the overtly expressed P-glycoprotein (P-gp) that guides in the rapid drug efflux of chemotherapy drugs. Despite continuous endeavors and ground-breaking achievements in the pursuit of finding better cancer therapeutic avenues, drug resistance is still a menace to hold back. Among newer therapeutic approaches, the application of phytonutrients such as alkaloids to suppress P-gp activity in drug-resistant cancers has found an exciting niche in the arena of alternative cancer therapies. In this work, we would like to present a black pepper alkaloid derivative known as BioPerine-loaded chitosan (CS)-polyethylene glycol (PEG) coated polylactic acid (PLA) hybrid polymeric nanoparticle to improve the bioavailability of BioPerine and its therapeutic efficacy in suppressing P-gp expression in MDA-MB 453 breast cancer cell line. Our findings revealed that the CS-PEG-BioPerine-PLA nanoparticles demonstrated a smooth spherical morphology with an average size of 316 nm, with improved aqueous solubility, and provided sustained BioPerine release. The nanoparticles also enhanced in vitro cytotoxicity and downregulation of P-gp expression in MDA-MB 453 cells compared to the commercial inhibitor verapamil hydrochloride, thus promising a piece of exciting evidence for the development of BioPerine based nano-drug delivery system in combination with traditional therapies as a crucial approach to tackling multi-drug resistance in cancers., Graphical abstract Image, graphical abstract

There are over 2 million cases a year of breast cancer, leading to over 600,000 deaths globally [1]. Despite these large numbers, increasingly more women are being cured with early stage disease and women with advanced disease are living longer [2]. The appreciation for molecular subtypes of the disease has led to significant therapeutic advances and estrogen receptor positive (ER+) breast cancer represents the largest of these subgroups. An appreciation for the importance of estrogen signaling in ER+ dates back to 1896 when Dr. George Thomas Beatson observed impressive disease responses after performing bilateral oophorectomy in 3 women at Glasgow Cancer Hospital [3]. The evolution of treatment for advanced disease from progestins, to the selective estrogen receptor modulator tamoxifen, and subsequently the aromatase inhibitors and the selective estrogen receptor degrader fulvestrant, has been accompanied by improved efficacy and decreased side effects. While the use of these drugs has changed the natural history of both early and advanced disease, it has been long recognized that many patients will develop resistance to this approach. After many years of trying to improve on single-agent endocrine treatment, since 2012 there has been an explosion of new drugs that have shown improved efficacy in combination with endocrine approaches. The first of these to receive FDA approval was the mTOR inhibitor everolimus (2012) [4], followed by the approval of 3 cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors [palbociclib (2015) [5], ribociclib (2018) [6], and abemaciclib (2018) [7]], and more recently the PI3-kinase inhibitor alpelisib (2019) [8]. In addition, chemotherapy is still used frequently when endocrine manipulations have been exhausted. Like other incurable malignancies, the goal in advanced ER+ breast cancer is to prolong survival and maintain quality of life. Currently, we have more tools available to achieve this than ever before and we will review the efficacy and side effect data with these agents that are driving physician choices for individual patients.

Transcriptional repressor zinc finger and BTB domain containing 1 (ZBTB1) is required for DNA repair. Because DNA repair defects often underlie genome instability and tumorigenesis, we determined to study the role of ZBTB1 in cancer. In this study, we found that ZBTB1 is down-regulated in breast cancer and this down-regulation is associated with poor outcome of breast cancer patients. ZBTB1 suppresses breast cancer cell proliferation and tumor growth. The majority of breast cancers are estrogen receptor (ER) positive and selective estrogen receptor modulators such as tamoxifen have been widely used in the treatment of these patients. Unfortunately, many patients develop resistance to endocrine therapy. Tamoxifen-resistant cancer cells often exhibit higher HER2 expression and an increase of glycolysis. Our data revealed that ZBTB1 plays a critical role in tamoxifen resistance in vitro and in vivo. To see if ZBTB1 regulates HER2 expression, we tested the recruitments of ZBTB1 on HER2 regulatory sequences. We observed that over-expressed ZBTB1 occupies the estrogen receptor α (ERα)-binding site of the HER2 intron in tamoxifen-resistant cells, suppressing tamoxifen-induced transcription. In an effort to identify potential microRNAs (miRNAs) regulating ZBTB1, we found that miR-23b-3p directly targets ZBTB1. MiR-23b-3p regulates HER2 expression and tamoxifen resistance via targeting ZBTB1. Finally, we found that miR-23b-3p/ZBTB1 regulates aerobic glycolysis in tamoxifen-resistant cells. Together, our data demonstrate that ZBTB1 is a tumor suppressor in breast cancer cells and that targeting the miR-23b-3p/ZBTB1 may serve as a potential therapeutic approach for the treatment of tamoxifen resistant breast cancer.

Introduction Tamoxifen is a non-steroidal anti-oestrogen that acts as an antagonist in breast tissue, neurosensory retina, and retinal pigment epithelium (RPE). The reported incidence of its ocular effects varies between 0.9% and 11%. Methods Case series. Multimodal image studies were used to evaluate three female patients who were receiving tamoxifen for breast cancer for the purpose of monitoring and determining whether there are changes after discontinuation of treatment. Results All three patients showed signs of crystalline retinopathy using spectral domain optical coherence tomography (SD-OCT) during follow-up. Conclusion The follow-up using multimodal imaging studies allowed evaluating the progression of the changes, providing a prognostic assessment. The findings found (visual acuity and multimodal imaging) confirmed the results of previous studies, indicating that, at a certain level of toxicity, the damage was irreversible.

Adjuvant endocrine therapy is an integral component of care for hormone-dependent breast cancer. Tamoxifen is a potent inducer of ovarian function and consequent hyperestrogenism in premenopausal women. However, the incidence rate and risk factors associated this phenomenon remain unclear.Data of patients younger than 60 years who received adjuvant tamoxifen therapy for hormone-dependent breast cancer (stages 0-III) and who underwent regular follow-up of laboratory results for follicle-stimulating hormone and estradiol levels were retrospectively analyzed. Univariate and multivariate analyses were performed to identify clinicopathologic factors related to ovarian hyperstimulation.Among 205 patients, 19 (9.3%) showed high values of serum estradiol during tamoxifen therapy. The mean (± SD) serum concentrations of estradiol and follicle-stimulating hormone were 1047.97 ± 638.8 pg/mL and 11.5 ± 7.3 mIU/mL, respectively. A mean of 400.83 days elapsed from the start of the single administration of tamoxifen to the initial detection of a high concentration of estradiol. Univariate and multivariate analyses showed that younger age (40 years) and only endocrine therapy without chemotherapy were significantly related to a higher prevalence of ovarian hyperstimulation (P = .015, relative risk = 7.49 for age 40 years; P = .017, relative risk = 32.9 for no chemotherapy). Pathologic stages and tumor characteristics were not related to the manifestation of ovarian hyperstimulation.Young age (40 years) and endocrine treatment without chemotherapy were risk factors for the incidence of ovarian hyperstimulation during tamoxifen treatment. Close monitoring of endocrine parameters during treatment with tamoxifen especially in this patient group is essential.

Purpose The association between endocrine therapy and risk of dementia remains uncertain. We investigated the association between adjuvant endocrine therapy for breast cancer and risk of developing dementia in a real-world, population-based study. Methods We used health administrative data collected from post-menopausal women (aged ≥66 years) who were diagnosed with breast cancer and started on adjuvant endocrine therapy from 2005 to 2012 with follow-up until 2017. Patients were classified by the use of either an aromatase inhibitor or tamoxifen and followed to estimate the unadjusted cumulative incidence of developing dementia. A multivariable Cox proportional hazards model was created adjusting for age, income quintile, medical co-morbidities, and duration of endocrine therapy. Results We identified 12,077 patients of whom 73% were treated with an aromatase inhibitor and 27% with tamoxifen. Our multivariable analysis showed a lower rate of dementia in patients treated with an aromatase inhibitor as compared to tamoxifen [Hazard ratio (HR) = 0.88, 95% confidence interval (CI): 0.78–0.98, p-value = .02) at a median follow-up of 5.9 years. The 5-year dementia rate among patient treated with either an aromatase inhibitor or tamoxifen was 7.4% and 9.2% respectively. Older age, previous history of ischemic heart disease, diabetes, hypertension and history of stroke were all significantly associated with the development of dementia. Conclusion Aromatase inhibitor therapy was associated with a decreased incidence of dementia as compared to treatment with tamoxifen among post-menopausal women with early stage breast cancer. Further prospective studies with longer-term follow-up investigating the neurocognitive effects of endocrine therapy are warranted.

Background & Aims Paneth cells (PCs) synthesize and secrete antimicrobial peptides that are key mediators of host-microbe interactions, establishing a balance between intestinal microflora and enteric pathogens. We observed that their number increases in experimental portal hypertension and aimed to investigate the mechanisms by which these cells can contribute to the regulation of portal pressure. Methods We first treated Math1Lox/LoxVilcreERT2 mice with tamoxifen to induce the complete depletion of intestinal PCs. Subsequently, we performed partial portal vein or bile duct ligation. We then studied the effects of these interventions on hemodynamic parameters, proliferation of blood vessels and the expression of genes regulating angiogenesis. Intestinal organoids were cultured and exposed to different microbial products to study the composition of their secreted products (by proteomics) and their effects on the proliferation and tube formation of endothelial cells (ECs). In vivo confocal laser endomicroscopy was used to confirm the findings on blood vessel proliferation. Results Portal hypertension was significantly attenuated in PC-depleted mice compared to control mice and was associated with a decrease in portosystemic shunts. Depletion of PCs also resulted in a significantly decreased density of blood vessels in the intestinal wall and mesentery. Furthermore, we observed reduced expression of intestinal genes regulating angiogenesis in Paneth cell depleted mice using arrays and next generation sequencing. Tube formation and wound healing responses were significantly decreased in ECs treated with conditioned media from PC-depleted intestinal organoids exposed to intestinal microbiota-derived products. Proteomic analysis of conditioned media in the presence of PCs revealed an increase in factors regulating angiogenesis and additional metabolic processes. In vivo endomicroscopy showed decreased vascular proliferation in the absence of PCs. Conclusions These results suggest that in response to intestinal flora and microbiota-derived factors, PCs secrete not only antimicrobial peptides, but also pro-angiogenic signaling molecules, thereby promoting intestinal and mesenteric angiogenesis and regulating portal hypertension. Lay summary Paneth cells are present in the lining of the small intestine. They prevent the passage of bacteria from the intestine into the blood circulation by secreting substances to fight bacteria. In this paper, we discovered that these substances not only act against bacteria, but also increase the quantity of blood vessels in the intestine and blood pressure in the portal vein. This is important, because high blood pressure in the portal vein may result in several complications which could be targeted with novel approaches.

Purpose The Prosigna-PAM50 risk of recurrence (ROR) score has documented clinical utility for the prediction of 10-year distant recurrence (DR). The present study investigated the value of Prosigna-PAM50 for predicting 10-year DR and overall survival after 5 years of endocrine treatment for postmenopausal patients with invasive lobular carcinoma. Patients and Methods Using the Danish Breast Cancer Group database, we identified patients with a diagnosis from 2000 to 2003 of estrogen receptor-positive, human epidermal growth factor receptor 2-negative invasive ductal (n = 1570) or lobular (n = 341) cancer > 20 mm or 1 to 3 positive lymph nodes and applied multivariate Cox models. Results The median follow-up for DR was 9.3 years and for overall survival 15.2 years. Of the 341 lobular and 1570 ductal cases, 140 (41%) and 349 (22%) were classified as low ROR, with a 10-year DR rate of 7.7% (95% confidence interval [CI], 3.7%-13.6%) and 3.5% (95% CI, 1.8%-6.2%), respectively. The 10-year DR rate for the intermediate ROR group for those with lobular cancer was 18% (95% CI, 10.1%-27.9%) compared with 9.7% (95% CI, 6.7%-13.4%) for those with ductal cancer. Luminal B tumors had a significantly worse outcome than luminal A tumors in both lobular (hazard ratio, 1.89; 95% CI, 1.03%-3.45%; P = .04) and ductal (hazard ratio, 3.18; 95% CI, 2.29%-4.43%; P Conclusion Prosigna PAM-50 provides significant prognostic information beyond the clinicopathologic factors in patients with invasive lobular breast cancer. Those with lobular cancer had worse 10-year DR rates compared with those with ductal cancer in the same ROR category. Our results could have an effect on the treatment decisions regarding the addition of chemotherapy for those in the intermediate ROR group.

Background We performed a retrospective study on the efficacy and safety of sirolimus (an mTOR inhibitor) in hormone receptor (HR)-positive advanced breast cancer and searched for biomarkers to predict its efficacy. Methods All patients with HR-positive metastatic breast cancer treated with sirolimus plus endocrine therapy between December 2017 and July 2018 at the Cancer Hospital, Chinese Academy of Medical Sciences were consecutively and retrospectively reviewed. Mutations in circulating tumour DNA (ctDNA) were assayed for 1021 tumour-related genes via gene panel target capture-based next-generation sequencing. Results Thirty-six patients with metastatic breast cancer treated with sirolimus plus endocrine therapy were included. The progression-free survival (PFS) rates between the sirolimus group and everolimus group were similar, and the median PFS was 4.9 months and 5.5 months, respectively (hazard ratio 1.56, 95% CI 0.86–2.81, P = 0.142). The objective response rate in the 36 patients was 19.4%, and the clinical benefit rate was 41.7%. Lipid metabolism disorder was the most common adverse event (69.4%), and 13.9% of patients had stomatitis. Most (94.4%) adverse events were grade 1–2. Twenty patients (55.6%) underwent ctDNA analysis before receiving sirolimus therapy. For patients who received less than 3 lines of chemotherapy, those with PI3K/Akt/mTOR pathway alterations had a better response to sirolimus than those without alterations, with a median PFS of 7.0 months vs 4.3 months (hazard ratio = 0.01, 95% CI 0.00–0.34, P = 0.010). Conclusions Sirolimus is a potentially effective treatment option for patients with HR-positive advanced breast cancer., Highlights • Sirolimus is a potentially effective treatment option for patients with hormone receptor-positive advanced breast cancer. • A previous chemotherapy line was a poor predictor of sirolimus efficacy. • PI3K/Akt/mTOR pathway alterations may affect the efficacy of sirolimus.

The present study was intended to develop a papain grafted S-protected hyaluronic acid-lithocholic acid co-block (PAP-HA-ss-LCA) polymeric excipient as an amphiphilic muco permeating stabilizer for targeting breast cancer epithelial cells overexpressed with CD44 receptors. The mucopermeating, stabilizing and targeting capability of the PAP-HA-ss-LCA polymeric excipient was investigated by manufacturing tamoxifen (TMX) loaded self-nanoemulsifying drug delivery system (SNEDDS). TMX loaded PAP-HA-ss-LCA incorporated SNEDDS (TMX-PAP-HA-ss-LCA SNEDDS) were characterized for their surface chemistry, drug release, permeation enhancement, biocompatibility and antitumor activity. FTIR spectroscopic analysis showed successful synthesis of PAP-HA-ss-LCA polymer. X-ray diffraction (XRD) showed the amorphous form of TMX inside SNEDDS. The observed hydrodynamic diameter of TMX-PAP-HA-ss-LCA SNEDDS was 367.5 nm. Furthermore, Hyaluronic Acid-based Mucoadhesive Self Nanoemulsifying Drug Delivery System (SNEDDS) of TMX showed homogeneity in synthesis with low polydispersity and negative zeta potential due to stabilization with PAP-HA-ss-LCA polymer. The distinct spherical shape of the nanodroplets was evident by transmission electron microscopy (TEM). In vitro release kinetics indicated approximately >80% release within 48 h under sink conditions. Ex-vivo permeation study displayed 7.11-folds higher permeation of TMX by TMX-PAP-HA-ss-LCA in contrast to pure TMX. The biocompatibility study proved that SNEDDS formulation was safe and compatible against macrophages. In vitro cytotoxicity studies demonstrated that TMX-PAP-HA-ss-LCA SNEDDS could efficiently kill MCF-7 breast cancer cells as compared to the native TMX drug. Systemic toxicity studies proved the non-toxic nature of TMX-PAP-HA-ss-LCA in contrast to pure TMX. Based on these evidences, TMX-PAP-HA-ss-LCA SNEDDS formulation seems to be promising mucopermeating, augmented intracellular uptake with strong targeting potential for anti-proliferative activity.

Introduction Tamoxifen is a widely used hormonal based therapy for breast cancer in the adjuvant and metastatic setting, prolonging overall and recurrence-free survival. There has been increasing interest in the potential for novel “off-target” effects of tamoxifen and its metabolite N-desmethyltamoxifen across a number of cancer types. We aim to review the current literature regarding the potential use of tamoxifen in other primary malignancies. Method A qualitative systematic review was performed according to the PRISMA guidelines using pre-set search criteria across the PubMed, Cochrane and Scopus databases from 1985 to 2019. Additional results were generated from included papers references. Results A total of 324 papers were identified, of which 47 were included; a further 29 articles were obtained from additional referencing to give a total of 76 articles. Clinical trials have demonstrated benefits with the use of tamoxifen in isolation and combination, specifically in patients with advanced non-resectable malignancy, however results are not consistent across the literature. In vivo data consistently suggests that off target effects of tamoxifen are mediated through the ceramide pathway or through inhibition of protein kinase C (PKC). Conclusions With increased focus upon the potential of repurposing drugs, tamoxifen may be a candidate for repurposing in the wider cancer setting. There is evidence to suggest that the ceramide or PKC pathway could act as a therapeutic target for tamoxifen or alternative chemotherapeutics and merits further investigation.

Homozygous deletion of chromodomain helicase DNA binding protein 1 (CHD1) is among the most frequent genetic alterations in prostate cancer. CHD1 is converted from a non-essential to an essential gene for prostate cancer cell survival when phosphatase and tensin homolog (PTEN), another frequently deleted gene in prostate cancer, is disrupted. It remains unknown whether this PTEN-CHD1 genetic and functional relationship also operates in other solid tumors. Here, we address this question by using genetically engineered mouse models. Inducible deletion of Pten and p53 in all somatic cells of adult mice led to widespread PI3K/Akt pathway activation and hyperplastic phenotypes, causing multi-organ failure and lethality. Remarkably, when Chd1 was co-deleted in the Pten/p53 model, the lethality remained unperturbed. At the protein level, Chd1 was stabilized upon Pten deletion in prostate, but not in other organs examined (lung, liver, kidney, colon, mammary). These results shed mechanistic insight on the cancer type-specific copy number alteration pattern of PTEN and CHD1.

Consumption of Cytochrome P450 2D6 (CYP2D6) inhibiting drugs along with tamoxifen treatment results in decrease in plasma concentration of endoxifen, the major active tamoxifen metabolite. Simultaneous use of CYP2D6 inhibitors, such as selective serotonin reuptake inhibitors (SSIs), as well as lesser tamoxifen adherence may negatively impact tamoxifen efficacy in patients with breast cancer. The objective of our study was to assess the co-prescription of CYP2D6 inhibitors and tamoxifen use and also to relate concomitant CYP2D6 inhibitor use and tamoxifen adherence to breast cancer in Riyadh, Saudi Arabia. All patients treated for breast cancer who had at least one tamoxifen prescription in their electronic medical records (EMRs) from June 2015 to June 2017 were included. Patients who had other adjuvant hormonal therapy were excluded from the study. In total, 499 patients (25 males and 474 females) with breast cancer using tamoxifen were included. Our study was purely observational study revealed that prescription of weak inhibitors with tamoxifen increased in the second year as opposed to decrease in the prescription of strong inhibitors. Also, a substantial percentage of patient population were found to be non-adherent to the tamoxifen therapy in this study. Keywords: Adherence, Breast cancer, CYP2D6 inhibitor, Tamoxifen

Breast cancer endocrine resistance prevents unleashing full capabilities of Tamoxifen (TMX), besides TMX off-target side effects on healthy tissue. In this study, we engineered TMX nanocomposite via co-loading it on alginate-based silver nanoparticles and embedding within folic acid-polyethylene glycol surface conjugate. The coating process was done by w/o/w double emulsion method. To confirm the silver nanoparticles formation, UV spectroscopy, XRD and TEM analysis were carried out. TEM results confirmed the core-shell structure of folate targeted nanocomposite with approximate average diameter of 66 nm, the nanocomposite structures were characterized by FTIR, TGA and SEM. By comparing with the non-targeted formula, folate decorated formula had 12-folds lowered IC50 value and 12.5–14-fold higher cancer cells toxic selectivity index. Also, after 4 h treatment, both fluorescence microscopic and flow cytometric analysis indicated higher intracellular accumulation of folic acid conjugated formula on MCF-7 cancer cells than the non-targeted one with 3.44-folds. The breast cancer cytotoxic effects of this metal-endocrine nanocomposite formula could be explained by the induction of reactive oxygen species (ROS), down regulation of survival oncogenic genes (BCL-2 and Survivin) and the accumulation of MCF-7 cells in G2/M phase. All these data confirm the efficiency and efficacy of the formulated nanocomposite as future treatment for breast cancer.

Tamoxifen is a successful endocrine therapy drug for estrogen receptor–positive (ER+) breast cancer. However, resistance to tamoxifen compromises the efficacy of endocrine treatment. In the present study, we identified potential tamoxifen resistance–related gene markers and investigated their mechanistic details. First, we established two ER + breast cancer cell lines resistant to tamoxifen, named MCF-7/TMR and BT474/TMR. Gene expression profiling showed that CXXC finger protein 4 (CXXC4) expression is lower in MCF-7/TMR cells than in MCF-7 cells. Furthermore, CXXC4 mRNA and protein expression are lower in the resistant cell lines than in the corresponding parental cell lines. We also investigated the correlation between CXXC4 and endocrine resistance in ER + breast cancer cells. CXXC4 knockdown accelerates cell proliferation in vitro and in vivo and renders breast cancer cells insensitive to tamoxifen, whereas CXXC4 overexpression inhibits cancer cell growth and increases tamoxifen sensitivity of resistant cells. In addition, we demonstrated that CXXC4 inhibits Wnt/β-catenin signaling in cancer cells by modulating the phosphorylation of GSK-3β, influencing the integrity of the β-catenin degradation complex. Silencing the CXXC4 gene upregulates expression of cyclinD1 and c-myc (the downstream targets of Wnt signaling) and promotes cell cycle progression. Conversely, ectopic expression of CXXC4 downregulates the expression of these proteins and arrests the cell cycle in the G0/G1 phase. Finally, the small-molecule inhibitor XAV939 suppresses Wnt signaling and sensitizes resistant cells to tamoxifen. These results indicate that components of Wnt pathway that are early in response to tamoxifen could be involved as an intrinsic factor of the transition to endocrine resistance, and inhibition of Wnt signaling may be an effective therapeutic strategy to overcome tamoxifen resistance. Keywords: CXXC finger protein 4, CXXC4, Estrogen receptor–positive breast cancer, Tamoxifen resistance, Cell cycle, Wnt/β-catenin

In the last four decades, treatment of oestrogen receptor positive (ER+) breast cancer (BCa), has focused on targeting the estrogenic receptor signaling pathway. This signaling function is pivotal to sustain cell proliferation. Tamoxifen, a competitor inhibitor of oestrogen has played a major role in therapeutics. However, primary and acquired resistance to hormone blockade occurred in a large subset of these cancers, and new approaches were urgently needed. Aromatase inhibitors and receptor degraders were approved and alternatively used. Yet, resistance appears in the metastatic setting. Here we report the design and synthesis of a series of proteolysis targeting chimeras (PROTACs) that induce the degradation of estrogen receptor alpha in breast cancer MCF-7 (ER+) cells at nanomolar concentration. Using a warhead based on 4-hydroxitamoxifen, bifunctional degraders recruiting either cereblon or the Von Hippel Lindau E3 ligases were synthesized. Our efforts resulted in the discovery of TAM-VHL-1, a potent ERα degrader (DC50: 4.5 nM) that we envisage as a useful tool for biology study and a platform for potential therapeutics.

Aggrecan (Acan) is a large proteoglycan molecule constituting the extracellular matrix of cartilage, secreted by chondrocytes. To specifically target the chondrocyte lineage, researchers have widely used the AcanCreER mouse model. Evaluation of specificity and efficiency of recombination, requires Cre animals to be crossed with reporter mice. In order to accurately interpret data from Cre models, it is imperative to consider A) the amount of recombination occurring in cells/tissues that are not intended for targeting (i.e., non-specific expression), B) the efficiency of Cre recombination, which can depend on dose and duration of tamoxifen treatment, and C) the activation of CreER without tamoxifen induction, known as "Cre leakage." Using a highly sensitive reporter mouse (Ai9, tdTomato), we performed a comprehensive analysis of the AcanCreER system. Surprisingly, we observed expression in cells within the periosteum. These cells expand at a stage when chondrocytes are not yet present within the forming callus tissue (Acan/Ai9

For young patients with hormone receptor-positive early breast cancer, tamoxifen for at least 5 years is the standard endocrine treatment. Prolonged endocrine treatment over 5 years is recommended for patients with high risk of late relapse. When adjuvant chemotherapy is indicated, prolonged iatrogenic amenorrhea is a strong pronostic factor. WIthout persistant amenorrhea after chemotherapy, it is indicated to associate ovarian suppression to the endocrine treatment. Optimal duration of this induced amenorrhea is unknown.

Resume Introduction : Objectifs : Evaluer la tolerance du Tamoxifene (TAM) en termes d’effets secondaires et statut hormonal, la persistance du traitement sur cinq ans et rapporter les donnees du suivi lointain. Methodes : La population etudiee a inclus 55 patientes entre janvier 2001 et novembre 2002 a l’Institut de cancerologie de Lorraine, de 50 ans ou moins, traitees par TAM a la dose quotidienne de 20 mg, pour une duree prevue de 5 ans, en situation adjuvante, pour un cancer du sein, non menopausees au diagnostic. Les donnees du suivi au-dela de 24 mois apres l’introduction du TAM ont ete recueillies retrospectivement entre janvier et mars 2019. Resultats : Les incidences cumulees de l’apparition de kystes ovariens et de bouffees de chaleur a 5 ans etaient respectivement de 68,5 et 77,6 %. Parmi les 33 patientes en amenorrhee chimio-induite, la moitie ont eu une reprise des cycles dans un delai median de 9 mois. Chez les 10 patientes sans amenorrhee chimio-induite, 4 ont eu un arret des cycles. Parmi elles, 3 patientes ont eu une reprise des cycles dans un delai de 1, 4 et 8 mois. Trente-quatre patientes (61,3 %) avaient pris du TAM au moins 5 ans. A 15 ans, les survies globale et sans progression etaient respectivement 90,7 et 67,4 %. Conclusion : L’observation de la tolerance du traitement pendant les 5 ans et au-dela contribue a la qualite des informations delivrees aux futures patientes debutant le traitement, permettant une meilleure comprehension et a terme une meilleure observance.

Pericytes are mural cells that cover small blood vessels. While defects in pericyte coverage are known to be involved in various vessel related pathologies, including diabetic retinopathy, the molecular mechanisms underlying pericyte coverage are not fully understood. In this study, we investigated the contribution of the forkhead transcription factor FOXO1 in endothelial cells to pericyte coverage in the developing retina. We observed retinal pericytes in tamoxifen-inducible endothelium-specific Foxo1 deletion mice. Tamoxifen was injected at postnatal day 1-3 and the retinas were harvested at P21. Our results demonstrated that Foxo1 deletion in the endothelium affected arteriole pericyte morphology without altering pericyte number, proliferation, and apoptosis. We hypothesized that abnormal pericyte morphogenesis in the knockout retina was caused by impaired pericyte differentiation. FOXO1 silencing by siRNA in the primary artery endothelium further revealed that THBS1 (thrombospondin 1), which promotes pericyte differentiation via TGFβ activation, was reduced in the FOXO1-deficient endothelium. Immunohistochemistry of FOXO1 knockout mice showed reduced numbers of phospho-Smad3+ arteriole pericytes compared with wild-type mice. In addition, endothelium-pericyte co-culture analysis revealed that pericytes cultured with FOXO1-deficient endothelial cells failed to differentiate sufficiently; this failure was partially rescued by the addition of recombinant THBS1 to the supernatant. The findings suggest that endothelial FOXO1 contributes to pericyte differentiation via regulation of THBS1 expression. This study provides new insights into the molecular mechanism of pericyte coverage in the context of endothelium-derived regulation and highlights a new therapeutic target for pericyte-related pathology.