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E2 suppressed the expression of PPARγ target gene ACOX3 in three breast cancer cell lines. MCF-7 cells were transferred from phenol red containing medium to E2-free medium for 3 days. Next, (A) MCF-7, (B) MCF-7:5C, and (C) MCF-7:2A cells were seeded in six-well plates. After 24 hours, cells were treated with a vehicle control (0.1% EtOH) or E2 (1 nM) for 24, 48, 72 hours. Cells were then harvested in TRIzol reagent. ACOX3 expression levels were quantitated using RT-PCR. *P

Supplementary written materials including Supplementary figure/table legends

Table S5

Peroxisome proliferator-activated receptor γ (PPARγ) is an important transcription factor that modulates lipid metabolism and inflammation. However, it remains unclear whether PPARγ is involved in modulation of estrogen (E2)-induced inflammation, thus affecting apoptosis of E2-deprived breast cancer cells, MCF-7:5C and MCF-7:2A. Here, we demonstrated that E2 treatment suppressed the function of PPARγ in both cell lines, although the suppressive effect in MCF-7:2A cells was delayed owing to high PPARγ expression. Activation of PPARγ by a specific agonist, pioglitazone, selectively blocked the induction of TNFα expression by E2, but did not affect other adipose inflammatory genes, such as fatty acid desaturase 1 and IL6. This suppression of TNFα expression by pioglitazone was mainly mediated by transrepression of nuclear factor-κB (NF-κB) DNA-binding activity. A novel finding was that NF-κB functions as an oxidative stress inducer in MCF-7:5C cells but an antioxidant in MCF-7:2A cells. Therefore, the NF-κB inhibitor JSH-23 displayed effects equivalent to those of pioglitazone, with complete inhibition of apoptosis in MCF-7:5C cells, but it increased E2-induced apoptosis in MCF-7:2A cells. Depletion of PPARγ by siRNA or the PPARγ antagonist T0070907 accelerated E2-induced apoptosis, with activation of NF-κB–dependent TNFα and oxidative stress. For the first time, we demonstrated that PPARγ is a growth signal and has potential to modulate NF-κB activity and oxidative stress in E2-deprived breast cancer cell lines. All of these findings suggest that anti-PPARγ therapy is a novel strategy to improve the therapeutic effects of E2-induced apoptosis in E2-deprived breast cancer.

Supplementary figure/table materials except Table S1 and Table S5

Patients with long-term estrogen-deprived breast cancer, after resistance to tamoxifen or aromatase inhibitors develops, can experience tumor regression when treated with estrogens. Estrogen's antitumor effect is attributed to apoptosis via the estrogen receptor (ER). Estrogen treatment can have unpleasant gynecologic and nongynecologic adverse events; thus, the development of safer estrogenic agents remains a clinical priority. Here, we study synthetic selective estrogen mimics (SEM) BMI-135 and TTC-352, and the naturally occurring estrogen estetrol (E4), which are proposed as safer estrogenic agents compared with 17β-estradiol (E2), for the treatment of endocrine-resistant breast cancer. TTC-352 and E4 are being evaluated in breast cancer clinical trials. Cell viability assays, real-time PCR, immunoblotting, ERE DNA pulldowns, mass spectrometry, X-ray crystallography, docking and molecular dynamic simulations, live cell imaging, and Annexin V staining were conducted in 11 biologically different breast cancer models. Results were compared with the potent full agonist E2, less potent full agonist E4, the benchmark partial agonist triphenylethylene bisphenol (BPTPE), and antagonists 4-hydroxytamoxifen and endoxifen. We report ERα's regulation and coregulators’ binding profiles with SEMs and E4. We describe TTC-352′s pharmacology as a weak full agonist and antitumor molecular mechanisms. This study highlights TTC-352′s benzothiophene scaffold that yields an H-bond with Glu353, which allows Asp351-to-helix 12 (H12) interaction, sealing ERα's ligand-binding domain, recruiting E2-enriched coactivators, and triggering rapid ERα-induced unfolded protein response (UPR) and apoptosis, as the basis of its anticancer properties. BPTPE's phenolic OH yields an H-Bond with Thr347, which disrupts Asp351-to-H12 interaction, delaying UPR and apoptosis and increasing clonal evolution risk.

Patients with long-term estrogen-deprived breast cancer, after resistance to tamoxifen or aromatase inhibitors develops, can experience tumor regression when treated with estrogens. Estrogen's antitumor effect is attributed to apoptosis via the estrogen receptor (ER). Estrogen treatment can have unpleasant gynecologic and nongynecologic adverse events; thus, the development of safer estrogenic agents remains a clinical priority. Here, we study synthetic selective estrogen mimics (SEM) BMI-135 and TTC-352, and the naturally occurring estrogen estetrol (E4), which are proposed as safer estrogenic agents compared with 17β-estradiol (E2), for the treatment of endocrine-resistant breast cancer. TTC-352 and E4 are being evaluated in breast cancer clinical trials. Cell viability assays, real-time PCR, immunoblotting, ERE DNA pulldowns, mass spectrometry, X-ray crystallography, docking and molecular dynamic simulations, live cell imaging, and Annexin V staining were conducted in 11 biologically different breast cancer models. Results were compared with the potent full agonist E2, less potent full agonist E4, the benchmark partial agonist triphenylethylene bisphenol (BPTPE), and antagonists 4-hydroxytamoxifen and endoxifen. We report ERα's regulation and coregulators’ binding profiles with SEMs and E4. We describe TTC-352′s pharmacology as a weak full agonist and antitumor molecular mechanisms. This study highlights TTC-352′s benzothiophene scaffold that yields an H-bond with Glu353, which allows Asp351-to-helix 12 (H12) interaction, sealing ERα's ligand-binding domain, recruiting E2-enriched coactivators, and triggering rapid ERα-induced unfolded protein response (UPR) and apoptosis, as the basis of its anticancer properties. BPTPE's phenolic OH yields an H-Bond with Thr347, which disrupts Asp351-to-H12 interaction, delaying UPR and apoptosis and increasing clonal evolution risk.

Aim: Tamoxifen (TAM) resistance remains a clinical issue in breast cancer. The authors previously reported that 15-hydroxyprostaglandin dehydrogenase (HPGD) was significantly downregulated in tamoxifen-resistant (TAMr) breast cancer cell lines. Here, the authors investigated the relationship between HPGD expression, TAM resistance and prediction of outcome in breast cancer. Methods: HPGD overexpression and silencing studies were performed in isogenic TAMr and parental human breast cancer cell lines to establish the impact of HPGD expression on TAM resistance. HPGD expression and clinical outcome relationships were explored using immunohistochemistry and in silico analysis. Results: Restoration of HPGD expression and activity sensitised TAMr MCF-7 cells to TAM and 17β-oestradiol, whilst HPGD silencing in parental MCF-7 cells reduced TAM sensitivity. TAMr cells released more prostaglandin E2 (PGE2) than controls, which was reduced in TAMr cells stably transfected with HPGD. Exogenous PGE2 signalled through the EP4 receptor to reduce breast cancer cell sensitivity to TAM. Decreased HPGD expression was associated with decreased overall survival in ERα-positive breast cancer patients. Conclusions: HPGD downregulation in breast cancer is associated with reduced response to TAM therapy via PGE2-EP4 signalling and decreases patient survival. The data offer a potential target to develop combination therapies that may overcome acquired tamoxifen resistance.

Our clinically relevant finding is that glucocorticoids block estrogen (E(2))-induced apoptosis in long-term E(2)-deprived (LTED) breast cancer cells. However, the mechanism remains unclear. Here, we demonstrated that E(2) widely activated adipose inflammatory factors such as fatty acid desaturase 1 (FADS1), interleukin-6 (IL-6), and tumor necrosis factor α (TNFα) in LTED breast cancer cells. Activation of glucocorticoid receptor (GR) by the synthetic glucocorticoid dexamethasone (Dex) upregulated FADS1 and IL-6 but downregulated TNFα expression. Furthermore, Dex was synergistic or additive with E(2) in upregulating FADS1 and IL-6 expression, whereas it selectively and constantly suppressed TNFα expression induced by E(2) in LTED breast cancer cells. Regarding regulation of endoplasmic reticulum stress, Dex effectively blocked activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK) by E(2), but it had no inhibitory effects on inositol-requiring protein 1 alpha (IRE1α) expression increased by E(2). Consistently, results from reverse-phase protein array (RPPA) analysis demonstrated that Dex could not reverse IRE1α-mediated degradation of phosphoinositide 3-kinase (PI3K)/Akt-associated signal pathways activated by E(2). Unexpectedly, activated GR preferentially repressed nuclear factor-κB (NF-κB) DNA-binding activity and expression of NF-κB-dependent gene TNFα induced by E(2), leading to the blockade of E(2)-induced apoptosis. Together, these data suggest that trans-suppression of NF-κB by GR in the nucleus is a fundamental mechanism thereby blocking E(2)-induced apoptosis in LTED breast cancer cells. This study provided an important rationale for restricting the clinical use of glucocorticoids, which will undermine the beneficial effects of E(2)-induced apoptosis in aromatase inhibitor-resistant breast cancer patients.

Long-term estrogen deprivation (LTED) with tamoxifen (TAM) or aromatase inhibitors leads to endocrine-resistance, whereby physiologic levels of estrogen kill breast cancer (BC). Estrogen therapy is effective in treating patients with advanced BC after resistance to TAM and aromatase inhibitors develops. This therapeutic effect is attributed to estrogen-induced apoptosis via the estrogen receptor (ER). Estrogen therapy can have unpleasant gynecologic and nongynecologic adverse events. Here, we study estetrol (E4) and a model Selective Human ER Partial Agonist (ShERPA) BMI-135. Estetrol and ShERPA TTC-352 are being evaluated in clinical trials. These agents are proposed as safer estrogenic candidates compared with 17β-estradiol (E2) for the treatment of endocrine-resistant BC. Cell viability assays, real-time polymerase chain reaction, luciferase reporter assays, chromatin immunoprecipitation, docking and molecular dynamics simulations, human unfolded protein response (UPR) RT2 PCR profiler arrays, live cell microscopic imaging and analysis, and annexin V staining assays were conducted. Our work was done in eight biologically different human BC cell lines and one human endometrial cancer cell line, and results were compared with full agonists estrone, E2, and estriol, a benchmark partial agonist triphenylethylene bisphenol (BPTPE), and antagonists 4-hydroxytamoxifen and endoxifen. Our study shows the pharmacology of E4 and BMI-135 as less-potent full-estrogen agonists as well as their molecular mechanisms of tumor regression in LTED BC through triggering a rapid UPR and apoptosis. Our work concludes that the use of a full agonist to treat BC is potentially superior to a partial agonist given BPTPE's delayed induction of UPR and apoptosis, with a higher probability of tumor clonal evolution and resistance. SIGNIFICANCE STATEMENT: Given the unpleasant gynecologic and nongynecologic adverse effects of estrogen treatment, the development of safer estrogens for endocrine-resistant breast cancer (BC) treatment and hormone replacement therapy remains a priority. The naturally occurring estrogen estetrol and Selective Human Estrogen-Receptor Partial Agonists are being evaluated in endocrine-resistant BC clinical trials. This work provides a comprehensive evaluation of their pharmacology in numerous endocrine-resistant BC models and an endometrial cancer model and their molecular mechanisms of tumor regression through the unfolded protein response and apoptosis.

High-dose synthetic estrogen therapy was the standard treatment of advanced breast cancer for three decades until the discovery of tamoxifen. A range of substituted triphenylethylene synthetic estrogens and diethylstilbestrol were used. It is now known that low doses of estrogens can cause apoptosis in long-term estrogen deprived (LTED) breast cancer cells resistant to antiestrogens. This action of estrogen can explain the reduced breast cancer incidence in postmenopausal women over 60 who are taking conjugated equine estrogens and the beneficial effect of low-dose estrogen treatment of patients with acquired aromatase inhibitor resistance in clinical trials. To decipher the molecular mechanism of estrogens at the estrogen receptor (ER) complex by different types of estrogens-planar [17β-estradiol (E2)] and angular triphenylethylene (TPE) derivatives-we have synthesized a small series of compounds with either no substitutions on the TPE phenyl ring containing the antiestrogenic side chain of endoxifen or a free hydroxyl. In the first week of treatment with E2 the LTED cells undergo apoptosis completely. By contrast, the test TPE derivatives act as antiestrogens with a free para-hydroxyl on the phenyl ring that contains an antiestrogenic side chain in endoxifen. This inhibits early E2-induced apoptosis if a free hydroxyl is present. No substitution at the site occupied by the antiestrogenic side chain of endoxifen results in early apoptosis similar to planar E2 The TPE compounds recruit coregulators to the ER differentially and predictably, leading to delayed apoptosis in these cells. SIGNIFICANCE STATEMENT: In this paper we investigate the role of the structure-function relationship of a panel of synthetic triphenylethylene (TPE) derivatives and a novel mechanism of estrogen-induced cell death in breast cancer, which is now clinically relevant. Our study indicates that these TPE derivatives, depending on the positioning of the hydroxyl groups, induce various conformations of the estrogen receptor's ligand-binding domain, which in turn produces differential recruitment of coregulators and subsequently different apoptotic effects on the antiestrogen-resistant breast cancer cells.

Estrogen therapy was used to treat advanced breast cancer in postmenopausal women for decades until the introduction of tamoxifen. Resistance to long-term estrogen deprivation (LTED) with tamoxifen and aromatase inhibitors used as a treatment of breast cancer inevitably occurs, but unexpectedly low-dose estrogen can cause regression of breast cancer and increase disease-free survival in some patients. This therapeutic effect is attributed to estrogen-induced apoptosis in LTED breast cancer. Here, we describe modulation of the estrogen receptor (ER) liganded with antiestrogens (endoxifen and 4-hydroxytamoxifen) and an estrogenic triphenylethylene (TPE), ethoxytriphenylethylene (EtOXTPE), on estrogen-induced apoptosis in LTED breast cancer cells. Our results show that the angular TPE estrogen (EtOXTPE) is able to induce the ER-mediated apoptosis only at a later time compared with planar estradiol in these cells. Using real-time polymerase chain reaction, chromatin immunoprecipitation, western blotting, molecular modeling, and X-ray crystallography techniques, we report novel conformations of the ER complex with an angular estrogen EtOXTPE and endoxifen. We propose that alteration of the conformation of the ER complexes, with changes in coactivator binding, governs estrogen-induced apoptosis through the protein kinase regulated by RNA-like endoplasmic reticulum kinase sensor system to trigger an unfolded protein response.

Prostate and breast cancer are the two cancers with the highest incidence in men and women, respectively. Here, we focus on the known biology of acquired resistance to antihormone therapy of prostate and breast cancer and compare laboratory and clinical similarities in the evolution of the disease. Laboratory studies and clinical observations in prostate and breast cancer demonstrate that cell selection pathways occur during acquired resistance to antihormonal therapy. Following sex steroid deprivation, both prostate and breast cancer models show an initial increased acquired sensitivity to the growth potential of sex steroids. Subsequently, prostate and breast cancer cells either become dependent upon the antihormone treatment or grow spontaneously in the absence of hormones. Paradoxically, the physiologic sex steroids now kill a proportion of selected, but vulnerable, resistant tumor cells. The sex steroid receptor complex triggers apoptosis. We draw parallels between acquired resistance in prostate and breast cancer to sex steroid deprivation. Clinical observations and patient trials confirm the veracity of the laboratory studies. We consider therapeutic strategies to increase response rates in clinical trials of metastatic disease that can subsequently be applied as a preemptive salvage adjuvant therapy. The goal of future advances is to enhance response rates and deploy a safe strategy earlier in the treatment plan to save lives. The introduction of a simple evidence-based enhanced adjuvant therapy as a global healthcare strategy has the potential to control recurrence, reduce hospitalization, reduce healthcare costs and maintain a healthier population that contributes to society.

Balkees Abderrahman speaks to Roshaine Wijayatunga, managing commissioning editor: Balkees Abderrahman is a Fellow of Breast Medical Oncology at MD Anderson Cancer Center and a Fellow of the Royal Society of Medicine of Great Britain. She is a PhD trainee under model “Applicants of Very High Quality” at the Faculty of Medicine, The University of Leeds, West Yorkshire, Great Britain. She works with Professor V Craig Jordan, OBE, FMedSci. Dr. Abderrahman is the author of “Steroid Receptors in Breast Cancer, The Breast: Comprehensive Management of Benign and Malignant Diseases 2017”, “Hormones and Cancer, Oxford Textbook of Cancer Biology 2018”, “First Targeted Therapy – History of Tamoxifen, Estrogen Receptor and Breast Cancer, Cancer Drug Discovery and Development, Springer Nature 2018” and “Selective Estrogen Receptor Modulators (SERMs), Estrogen Receptor and Breast Cancer, Cancer Drug Discovery and Development, Springer Nature 2018”. She has published several articles in breast cancer research. She is also the author of “Love at the Gate” and “Oliver and the Rock” and a contributor at Nature, the Pharmaceutical Journal of the Royal Pharmaceutical Society of Great Britain, The Independent, The American Society of Clinical Oncology (ASCO) Post, The Huffington Post, US News and World Report, The Hill and The Nation. She was a finalist for the Outstanding Youth Award at the United Nations from over 86 countries for “Her outstanding work in tackling some of our greatest social, economic, and environmental challenges”.

Extended adjuvant (5-10 years) therapy targeted to the estrogen receptor (ER) has significantly decreased mortality from breast cancer (BC). Areas covered: Translational research advanced clinical testing of extended adjuvant therapy with tamoxifen or aromatase inhibitors (AIs). Short term therapy or non-compliance increase recurrence, but surprisingly recurrence and death does not increase dramatically after 5 years of adjuvant therapy stops. Expert commentary: Compliance ensures optimal benefit from extended antihormone adjuvant therapy.Retarding acquired resistance using CDK4/6 or mTOR inhibitors is discussed. Preventing acquired resistance from mutations of ER could be achieved with Selective ER Downregulators (SERDs), eg fulvestrant. Fulvestrant is a depot injectable so oral SERDs are sought for extended use. In reality, a 'super SERD' which destroys ER but improves women's health like a Selective ER Modulator (SERM), would aid compliance to prevent recurrence and death. Estrogen-induced apoptosis occurs in 30% of BC with antihormone resistance. The 'one in three' rule that dictates that one in three unselected patients respond to either hormonal or antihormonal therapy in BC occurs with estrogen or antiestrogen therapy and must be improved. The goal is to maintain patients for their natural lives by blocking cancer cell survival through precision medicine using short cycles of estrogen apoptotic salvage therapy, and further extended antihormone maintenance.

Department of Breast Medical Oncology, University of Texas MD Anderson Cancer Center, 1500 Holcombe Boulevard Unit #1354, Houston, TX 77030, USA *Author for correspondence: Tel.: +1 713 745 0600; Fax.: +1 713 794 4385; VCJordan@mdanderson.org

During the past twenty years our understanding of the control of breast tumor development, growth and survival has changed dramatically. The once long forgotten application of high dose synthetic estrogen therapy as the first chemical therapy to treat any cancer has been resurrected, refined and reinvented as the new biology of estrogen-induced apoptosis. High dose estrogen therapy was cast aside once tamoxifen, from its origins as a failed “morning after pill”, was reinvented as the first targeted therapy to treat any cancer. The current understanding of the mechanism of estrogen-induced apoptosis is described as a consequence of acquired resistance to long term antihormone therapy in estrogen receptor (ER) positive breast cancer. The ER signal transduction pathway remains a target for therapy in breast cancer despite “antiestrogen” resistance, but becomes a regulator of resistance. Multiple mechanisms of resistance come into play: Selective ER Modulator (SERM) stimulated growth, growth factor/ER crosstalk, estrogen-induced apoptosis and mutations of ER. But it is with the science of estrogen-induced apoptosis that the next innovation in women’s health will be developed. Recent evidence suggests that the glucocorticoid properties of medroxyprogesterone acetate blunt estrogen-induced apoptosis in estrogen deprived breast cancer cell populations. As a result breast cancer develops during long-term Hormone Replacement Therapy (HRT). A new synthetic progestin with estrogen-like properties, such as the 19 nortestosterone derivatives used in oral contraceptives, will continue to protect the uterus from unopposed estrogen stimulation but at the same time, reinforce apoptosis in vulnerable populations of nascent breast cancer cells.

Disruption of estrogen signaling with tamoxifen or aromatase inhibitors (AI) is the clinical standard for the treatment of estrogen receptor-positive breast cancer, yet resistance to antiestrogen therapies is inevitable. The long-term E2-deprived breast cancer models MCF-7:5C and MCF-7:2A mimic AI resistance and moreover are vulnerable to E2-induced apoptosis due to the reconfiguration of their survival signaling. E2-induced apoptosis which results from the accumulation of endoplasmic reticulum (ER), oxidative, and inflammatory stresses, is a new paradigm to subvert endocrine resistance, with sensors of the unfolded protein response (UPR) being important mediators of ER stress (Ariazi et al. 2011; Fan et al. 2013, 2015). Here we asked whether epigenetic modifications may play a role in this and investigated genome-wide changes of 5C and 2A DNA methylation patterns that occurred during E2 stimulation during a 72h time course with WS8 cells as a reference. Methylation patterns were established using the Illumina Infinium HumanMethylation450 BeadChip (Service XS, Leiden, NL), and raw intensities were normalized and filtered using the bioconductor minfi package. A linear model (bioconductor limma package) has been built to detect differentially methylated CpGs. F-statistics were calculated by empirical Bayes moderation of standard errors with "trend" and "robust" set “on”. We also performed whole-genome bisulfite sequencing (WGBS) in untreated cells using the Illumina HiSeq platform (GATC Biotech, Konstanz, DE) to obtain maximum baseline CpG coverage. Trimmed WGBS reads were aligned to the hg38 genome (Bismarck, PMC3102221), duplicates removed, and methylation levels extracted with MethylDackel (https://github.com/dpryan79/MethylDackel) with a 3x coverage threshold (Wreczycka et al. 2017). Raw methylation levels were smoothed and differential methylation called using the bsseq package (Hansen et al. 2012). At baseline, WGBS-derived profiles showed a 2-fold higher degree of hypomethylation (beta Citation Format: Reiner Hoppe, Siarhei Kandabarau, Ping Fan, Stefan Winter, Balkees Abderrahman, Heather Cunliffe, Werner Schroth, V. Craig Jordan, Hiltrud B. Brauch. Genome-wide DNA methylation changes in AI-resistant breast cancer models during E2-treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 144.

Tamoxifen is the first selective estrogen receptor modulator. The extensive clinical and laboratory testing during the 1980s and 1990s raised questions about why there is target site specificity of tamoxifen in different species, i.e., tamoxifen is an estrogen in mice but a complete anti-estrogen in chicks. Additionally, tamoxifen has estrogen-like effects to lower circulating cholesterol, build postmenopausal bone in women, and stimulate the uterus and endometrial cancer growth but paradoxically prevents breast tumor growth. These observations lead to the SERM solution to prevent osteoporosis with a safe SERM but to prevent breast cancer at the same time. Raloxifene is the result with no increase in endometrial cancer incidence. There are now five FDA-approved SERMS available for use: tamoxifen, raloxifene, bazedoxifene, toremifene, and ospemifene. All have connections with discovery and basic research in Jordan’s laboratory.

The chance discovery of a new group of medicines called nonsteroidal anti-estrogens opened the door to new opportunities in therapeutics. Ethamoxytriphetol (MER25) was the first. However, based on studies in rats and mice, initial hopes were that nonsteroidal anti-estrogens would be new “morning after pills.” However, the discovery that clomiphene and tamoxifen induced ovulation in subfertile women would produce only a niche market in the 1960s. The treatment of metastatic breast cancer was an obvious choice as endocrine ablative surgery, i.e., oophorectomy, adrenalectomy, or hypophysectomy, was standard of care. Over a decade, in the 1970s, numerous nonsteroidal anti-estrogens were tested, but only tamoxifen went forward for the treatment of all stages of breast cancer, ductal carcinoma in situ, and male breast cancer and the reduction of risk for breast cancer in high-risk pre- and postmenopausal women.

The Women’s Health Initiative (WHI) consisted of two placebo controlled trials: one in women with a uterus, using Conjugated Equine Estrogen (CEE) plus medroxyprogesterone acetate (MPA), and the second trial in women without a uterus used CEE alone. The study population average age was approximately 63 years. Although the predicted rise in breast cancer occurred in the MPA plus CEE trial, the CEE alone trial, had a sustained decrease in breast cancer incidence. A unifying theory is presented that explains the decrease in breast cancer based on the new biology of estrogen-induced apoptosis in long term estrogen deprived nascent breast cancer cells. Glucocorticoids block estrogen-induced apoptosis and MPA has glucocorticoid activity. This is why MPA increases breast cancer when used with CEE as menopausal hormone replacement. A safer menopausal hormone therapy can now be designed with a more selective synthetic progestin such as norethindrone acetate.

The signing of the National Cancer Act in 1971 was designed to take laboratory discoveries rapidly from the bench to the bedside. A “war on cancer” had been declared. Combination cytotoxic chemotherapy was predicted to cure all cancers, based on the stunning success in treating childhood leukemia. Breast cancer treatments were primitive; radical mastectomy and radiation were standard of care for disease that had not spread. Ablative endocrine surgery (oophorectomy, hypophysectomy, and adrenalectomy) was a palliative last option for metastatic breast cancer. However, only 30% responded, surviving for only 1 or 2 years: every patient soon died. The discovery of the estrogen receptor (ER) and translation to breast cancer treatment triggered a revolution in women’s health. Two important but interconnected events occurred in 1972 at the Worcester Foundation for Experimental Biology (WFEB) that would exploit the breast tumor ER as the first target to save lives and prevent breast cancer development. Two new groups of medicines—selective ER modulators (SERMs) and aromatase inhibitors (AIs)—would continue the momentum of research at the WFEB to improve women’s health. Here, we recount the important progress made in women’s health based on knowledge of the endocrinology of breast cancer. We propose future opportunities in SERM therapeutics to “refresh” the current standards of care for breast cancer treatment. The opportunity is based on emerging knowledge about acquired resistance to long-term adjuvant AI therapy used to treat breast cancer.

Peroxisome proliferator-activated receptor γ (PPARγ) is an important transcription factor that modulates lipid metabolism and inflammation. However, it remains unclear whether PPARγ is involved in modulation of estrogen (E(2))-induced inflammation, thus affecting apoptosis of E(2)-deprived breast cancer cells, MCF-7:5C and MCF-7:2A. Here, we demonstrated that E(2) treatment suppressed the function of PPARγ in both cell lines, although the suppressive effect in MCF-7:2A cells was delayed owing to high PPARγ expression. Activation of PPARγ by a specific agonist, pioglitazone selectively blocked the induction of tumor necrosis factor alpha (TNFα) expression by E(2), but did not affect other adipose inflammatory genes, such as fatty acid desaturase 1(FADS1) and interleukin-6 (IL-6). This suppression of TNFα expression by pioglitazone was mainly mediated by trans-repression of nuclear factor-κB (NF-κB) DNA-binding activity. A novel finding was that NF-κB functions as an oxidative stress inducer in MCF-7:5C cells but an antioxidant in MCF-7:2A cells. Therefore, the NF-κB inhibitor JSH-23 displayed effects equivalent to those of pioglitazone, with complete inhibition of apoptosis in MCF-7:5C cells, but it increased E(2)-induced apoptosis in MCF-7:2A cells. Depletion of PPARγ by small interfering RNA or the PPARγ antagonist T0070907 accelerated E(2)-induced apoptosis, with activation of NF-κB-dependent TNFα and oxidative stress. For the first time, we demonstrated that PPARγ is a growth signal and has potential to modulate NF-κB activity and oxidative stress in E(2)-deprived breast cancer cell lines. All of these findings suggest that anti-PPARγ therapy is a novel strategy to improve the therapeutic effects of E(2)-induced apoptosis in E(2)-deprived breast cancer.

The estrogen receptor (ER) is the most important member of the nuclear receptor superfamily that controls the replication or apoptotic death of selected populations of breast cancer cells. The progesterone receptor is an estrogen-regulated protein in breast cancer that plays a role in predicting the hormone dependence of metastatic breast cancer. The mechanism of action of all effective antihormonal agents (tamoxifen, fulvestrant, aromatase inhibitors) is mediated through the ER signal transduction pathway and prevents estrogen action in the tumor cell. Tamoxifen is the pioneering selective ER modulator (SERM) that has estrogen-like effects in bone and the cardiovascular system, but antiestrogenic actions in breast cancer. The monthly depot injectable fulvestrant is a selective ER downregulator (SERD) that destroys the tumor ER and ERs throughout postmenopausal patient's body. There is a current search for an orally active SERD.

BACKGROUND A range of socio-demographic, organizational, physiological and psychological factors may influence peoples’ willingness to donate blood. Education had positive influence on attitudes towards blood donation as well as blood donors’ satisfaction to the time and location of donation. The most common misconceptions about blood donation were the risk of infection; selling donated blood to patients, and that blood donation believed to cause physical weakness. AIMS This paper is a report of a study of blood donation knowledge, attitudes and barriers. The aims of the study were to determine: (1) Jordanian blood donors’ level of knowledge of blood donation. (2) Jordanian blood donors’ attitudes towards donation. (3) Barriers influence blood donation in Jordan. METHODS A cross-sectional survey design was used to collect data from 500 blood donors between August 2011 and November 2011 using self-reported questionnaire. RESULTS Relatively inadequate knowledge about blood donation was found as only 28.6% of participants scored their knowledge above the average. Friends, encouraging media, and religion were influential factors affecting their knowledge and attitudes related to blood donation. CONCLUSION Since educational programs about blood donation are not frequently used in Jordan, there is a need to emphasize education as a key to improve population knowledge and attitudes towards blood donation.

The combined incidence and the extended disease course of breast and prostate cancer is a major challenge for health care systems. The solution for society requires an economically viable treatment strategy to maintain individuals disease free and productive, so as to avoid the fracture of the family unit. Forty years ago, translational research using the antiestrogen tamoxifen was targeted to estrogen receptor (ER) positive micrometastatic tumor cells and established the long-term antihormone adjuvant treatment strategy used universally today. The antihormone strategy was the accepted structure of cancer biology. Sex steroid deprivation therapy remains the orthodox strategy for the treatment of both breast and prostate cancer. Despite major initial therapeutic success, the strategies of long term anti-hormone therapies with either tamoxifen or aromatase inhibitors (AI) or antiandrogens or abiraterone for breast and prostate cancer, respectively, eventually lead to a significant proportion of anti-hormone resistant or stimulated tumor growth. Remarkably, a general principle of anti-hormone resistance has emerged for both breast and prostate cancer based primarily on clinical and supportive laboratory data. Paradoxically, anti-hormone resistant cell populations emerge and grow but are vulnerable to the cytotoxicity of estrogen or androgen-induced apoptosis for both breast and prostate cancer, respectively. These consistent anticancer actions of sex steroids appear to recapitulate the more complex mechanism of bone remodeling in elderly men and women during sex steroid deprivation. Estrogen is the key hormone in both sexes because in men androgen is first converted to estrogen. Estrogen regulates and triggers apoptosis in osteoclasts that develop during estrogen deprivation and destroy bone to cause osteoporosis. Sex steroid deprived breast and prostate cancer has recruited a streamlined natural apoptotic program from the human genome, but this is suppressed in the majority of sex steroid deprived tumors. Targeted strategies to neutralize cell survival pathways are now required to amplify and enhance sex steroid induced apoptosis. Successful blockade of the critical pathways for cell survival will introduce an inexpensive targeted therapy to maintain breast and prostate cancer patients indefinitely. Rotating anti-hormonal and sex steroid targeted cocktails could maintain patients at a microscopic tumor burden to enhance the quality of life, enhance survival, and maintain the family as a self-supporting and economically productive unit within society.

The undergrad joining the lab where I worked as a research fellow certainly knew how to make a first impression. “I looked up your work—cool stuff!” he said when we first met. “Fancy working with the best? That's me, of course!” He was clearly smart and ambitious. But I wasn't sure I was qualified to take someone under my wing. I had only started in research 2 years earlier, after finishing my medical degree. The bigger hurdle was the pressure to “publish or perish,” which made me hesitant to take on extra responsibilities. But, as I reflected on my own path into research and the crucial role played by my mentor, I realized that I needed to pay it forward. ![Figure][1] ILLUSTRATION: ROBERT NEUBECKER > “[My mentor's] character inspired me, and hopefully I will inspire my mentees.” I had always been interested in research. But for various reasons, I initially pursued medicine—until my medical school's final requirement that I complete a brief clinical training period elsewhere led to a serendipitous meeting. I was waiting outside my clinical supervisor's office when the prominent professor who worked in the next office came by. I knew who he was, and I was impressed with his lab's work developing breast cancer drugs, but I didn't expect him to recognize me. I was startled when he said, “I see you in every meeting. What are you working on?” I told him about myself and my work, and our conversation continued for more than an hour. His respectful, down-to-earth demeanor immediately made me feel at ease. He seemed to really care about what I had to say. When he learned that I was interested in research, he gave me a stack of papers to read and told me that he might have a spot for me in his lab. I didn't understand why this famous scientist would make space for me, someone with no research experience. But he saw something in me. After a proper interview, and finishing my medical degree, I joined the lab. In the beginning, I had no idea what I was doing. But my mentor was understanding and patient. With his support, I got my footing and was starting to feel like a real scientist. Now, it was time for me to do this for someone else. When I started as a mentor, I struggled a bit. I worried about accidentally teaching my mentee something inaccurate. Adjusting my teaching style to suit his learning curve was challenging at times. But we were patient with each other and worked together to develop a productive relationship. Following my own mentor's approach, I treated every encounter as a meeting of equals and encouraged open communication. My mentee asked tough questions. He challenged me and proved me wrong at times. And I loved it. By the end of his summer in the lab, I had a newfound appreciation for the rewards of being a mentor. Mentorship sharpened my communication, teaching, and technical skills, and it gave me a sense of purpose, confidence, and fulfillment. Since that undergrad left our lab, I have continued serving as a mentor for other students. Each relationship is enriching in its own way. Recently, for example, I learned how to support a mentee through failure. My current mentee and I had worked tirelessly to prepare for her university's undergraduate research competition, but she didn't win and was quite disappointed. I didn't want this one setback to extinguish her fire for research, so it was up to me to provide a positive, encouraging perspective. I took her out for dinner to celebrate her will to compete and the experience she had gained. And I told her about a recent disappointment of my own—losing a science communication competition—to show her that she was not alone. I was recently accepted into a split-site Ph.D. program at another institution, through which I will earn my research doctorate while continuing my current projects in my mentor's lab. This opportunity was only possible because my mentor took a chance on me. His character inspired me, and hopefully I will inspire my mentees similarly. There are many amazing individuals waiting for someone to apply just enough pressure to turn them from rock to diamond. We must all try to be those “someones.” [1]: pending:yes

Adjuvant endocrine therapy reduces the risk of recurrence and death from breast cancer in women with hormone receptor-positive early breast cancer. Tamoxifen has been the standard therapy for decades, and this is still the case for pre-menopausal women. Ovarian suppression is of similar efficacy but currently there is no strong evidence for adding this to tamoxifen and the additional morbidity can be considerable. Results from two important trials addressing this issue are imminent. In post-menopausal women, aromatase inhibitors (AIs) (letrozole, anastrozole, or exemestane) are superior to tamoxifen in preventing recurrence but only letrozole has been shown to improve survival. The main gain is against high-risk cancers, and tamoxifen gives very similar benefit for low-risk disease. Traditionally, treatment has been given for around 5 years, but many women remain at risk of relapse for 10 years or more. The AIs, and more recently tamoxifen, have been shown to reduce further the risk of late recurrence in women still in remission after 5 years of tamoxifen if given for a further 5 years. The comparative benefits of these two options and the selection of patients most likely to benefit from long-term adjuvant endocrine therapy are important topics for further research, as is the optimum duration of AI therapy started upfront.