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Cloning and sequencing of the progesterone receptor gene in dogs have revealed 2 isoforms, A and B, transcribed from a single gene. Distribution of isoforms A and B in canine mammary lesions has hitherto been investigated only by Western blot analysis. This study analyzed progesterone receptor and its isoforms in formalin-fixed, paraffin-embedded tissue samples from canine mammary lesions (4 dysplasias, 10 benign tumors, and 46 carcinomas) using 1-step SYBR Green quantitative real-time polymerase chain reaction (RT-qPCR). Progesterone receptor was expressed in 75% of dysplasias, all benign tumors, and 59% of carcinomas. Carcinomas, and particularly simple epithelial-type carcinomas, displayed the lowest levels of expression. A high rate of agreement was recorded between RT-qPCR and immunohistochemical labeling. Isoforms A and B were successfully amplified, with correlation coefficients of 0.99 and amplification efficiencies close to 2, and were expressed in all lesion types analyzed. Predominance of A over B expression was observed in carcinomas and complex adenomas. Low-grade tumors exhibited higher progesterone receptor messenger RNA (mRNA) levels, but no difference was observed in the expression of isoform A versus B. Analysis of progesterone receptor mRNA isoforms by RT-qPCR was successful in routinely formalin-fixed, paraffin-embedded tissue samples and enabled the distribution of isoforms A and B to be identified for the first time in dysplasias, benign tumors, and malignant tumors of the canine mammary gland. These findings will facilitate future research into the role of progesterone receptor isoforms in the progression of canine mammary tumors. [ABSTRACT FROM AUTHOR] more...

Background: The topoisomerase-1 (TOP1) targeting drug irinotecan may be a new effective drug in the treatment of metastatic breast cancer patients1,2. However, the use of irinotecan should be guided by predictive biomarkers to avoid drug-induced site effects in the non-responding subgroup of patients. A newly developed TOP1 fluorescence in situ hybridization (FISH)3 probe mix (Dako, Denmark) may represent such a novel predictive biomarker assay. Materials and Methods: The TOP1/CEN-20 FISH probe mix was applied to normal breast tissue (n = 100) and human breast cancer biopsy material (n = 42). TOP1 copy number variations (Affymetrix GeneChip 100k SNP array) and TOP1 mRNA levels (Affymetrix u133a GeneChip) were studied in 313 breast cancer samples4. Results: Employing FISH, the mean diploid TOP1 copy number in normal breast epithelium was 1.7 (range 1.45-1.90) and the diploid CEN-20 number was 1.6 (range 1.38-1.82). The normal diploid range was defined as the mean plus/minus 0.5 times the haploid gene copy number (Table 1 and 2). Using these values as cut-off, 13 (30.9%) of the 42 breast cancer samples had TOP1 gene copy number in the diploid range, 18 (42.9%) had 1 extra copy and 11 (26.2%) had ≥ 2 extra copies. CEN-20 counts showed that 19 (45.5%) had CEN-20 values within the diploid range, 21 (50%) had 1 extra copy and 2 (4.8%) had ≥ 2 extra copies. Calculating the TOP1/CEN-20 ratio showed that 6 (14.3%) of the patients samples had a ratio above 1.5, while none had a ratio < 0.8. The Pearson correlation between TOP1 and CEN-20 counts in the 42 breast cancer samples analyzed with FISH was 0.73. In the 313 breast cancer samples 34/313 (10.9%) had TOP1 copy gain and a significant association (p < 0.0001) was observed between TOP1 copy number and TOP1 mRNA. Conclusions: This study shows that about 25% of breast cancers have ≥ 2 extra copies of TOP1 as determined by FISH analyses. The high correlation between TOP1 and CEN20 in the 42 breast cancer samples challenges the use of the ratio. Moreover, the significant association between TOP1 gene copy number (SNP array) and TOP1 mRNA expression in breast cancer biopsies suggests that TOP1 FISH results will correlate with TOP1 protein amounts and may therefore be used to predict sensitivity to the TOP1 targeting drug irinotecan in breast cancer. However, a prospective clinical study is needed to prove or disprove this hypothesis. [ABSTRACT FROM AUTHOR] more...

Background: Topoisomerase 1 (TOP1) targeting drugs, e.g. irinotecan, are included in treatment regimens for different cancer types. Two clinical phase II studies1,2 suggested a role for irinotecan in the treatment of metastatic breast cancer patients being refractory to anthracyclines and taxanes. Access to predictive biomarker for irinotecan would increase response rates and secure that only patients with a high likelihood of obtaining benefit will receive the drug. However, no predictive biomarkers for TOP1 targeting drugs are available. Experimental design: A TOP1/CEN-20 fluorescence in situ hybridization (FISH) probe mix3 (Dako A/S, Denmark) was applied to analyze formalin fixed paraffin embedded (FFPE) tissue sections from 52 human breast cancer cell lines4. The FISH data were correlated to the gene expression levels (Affymetrix u133a GeneChip) of ER, HER2, TOP2A and molecular subtypes. Furthermore, gene expression data from 8 TOP1 high copy and 8 TOP1 low copy cell lines were applied for Kegg pathway analysis. Results: To categorize the cell lines, we initially analyzed the TOP1 copy number and CEN -20 counts in 100 normal breast epithelium sections and defined the normal diploid range as the mean plus/minus 0.5 times the haploid gene copy number. Thereby the normal diploid range for TOP1 was defined as 1.7 (range 1.45-1.90) and for CEN-20 it was 1.6 (range 1.38-1.82). By applying these cut-off values we found that among the 52 breast cancer cell lines 61.5% had TOP1 gene gains and 59.6% had increased CEN-20 copy numbers. However, the Pearson correlation between TOP1 and CEN-20 counts was 0.54 resulting in only 11.5% of the cell lines having TOP1 /CEN-20 ratios > 1.5. A significant association exist between TOP1 gene copy number (FISH) and TOP1 copy numbers obtained from SNP array analysis (p < 0.0001). Furthermore, a significant correlation between TOP1 gene copy number as determined by FISH and TOP1 mRNA was observed (Spearman correlation coefficient 0.5, p = 0.0012). This suggests that the TOP1 gene is actively transcribed. No significant correlations were observed between TOP1 copy number and ESR1, TOP2a and HER2 gene expression or between TOP1 copy numbers and breast cancer subtypes. Using Kegg pathway analysis, TOP1 copy numbers were found to be significantly associated with mismatch repair and DNA replication (multiple testing corrected p-value 0.016 and 0.018, respectively). Conclusion: This study shows that TOP1 DNA aberrations are a frequent finding in human breast cancer cell lines and that these aberrations are not associated with ERS1, HER2 and TOP2a gene expression or breast cancer subtypes. Moreover, TOP1 gene copy number was strongly associated with mismatch repair pathways. This study suggests that TOP1 copy numbers may be applicable as predictive biomarkerfor irinotecan-response. The potential predictive value of TOP1 FISH is currently being tested in the cell lines and in a clinical phase II study with metastatic breast cancer patients refractory to anthracyclines and taxanes. [ABSTRACT FROM AUTHOR] more...

Peripheral T-lymphocyte subsets: T-helper (OKT4) and T-suppressor (OKT8) cells were studied quantitatively in 20 patients with recurrent aphthous ulceration (RAU) in ulcerative, as well as inactive, stages of the disease. The figures were compared with T-lymphocyte subsets from matched control donors with no history of RAU. The ratio of T-helper: T-suppressor cells was significantly lower in both stages in the patients compared with controls due to a significantly increased number of T-suppressor cells in RAU patients. The number of T-helper cells in the patients did not differ significantly in either stage compared with controls. The study support the hypothesis of recurrent aphthous ulceration being a disorder of immunodeficiency. [ABSTRACT FROM AUTHOR] more...

Tissue inhibitor of metalloproteinases-1 (TIMP-1) regulates the proteolytic activity of matrix metalloproteinases (MMPs), playing an important role in the homeostasis of the extracellular matrix. Beyond its well-known role in tissue maintenance, TIMP-1 has been associated with multiple MMP-independent cytokine-like functions. The protein structure of TIMP-1, with two distinct domains, one interacting with MMPs and another able to bind multiple partners, provides a rationale for this multifunctionality. The identification of CD63 as a cell surface receptor for TIMP-1, able to mediate intracellular signaling through the Erk/MAPK axis, provided a molecular basis for the role of TIMP-1 in cellular signaling. However, several lines of evidence suggest that TIMP-1 may be able to associate with many interaction partners, thus attaining multiple functions. To enable the identification of previously unknown interaction partners that may underpin the core cellular functions of TIMP-1, known as well as unknown, we performed a yeast two-hybrid screening using a mammary gland complementary DNA (cDNA) library. We report here the identification of multiple interactors, including MHC class II-associated invariant chain γ (CD74). We verified that CD74 interacts with TIMP-1 in breast cancer cells and that this interaction contributes to cellular internalization of TIMP-1 and mediates intracellular signaling through the Akt signaling axis in breast cancer cells. These data provide new insights into the complex nature of the functions of TIMP-1 and their potential mechanistic basis., (© 2023 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.) more...

Multidrug resistance (MDR) is a major challenge in cancer treatment, and the breast cancer resistance protein (BCRP) is an important target in the search for new MDR-reversing drugs. With the aim of discovering new potential BCRP inhibitors, the crude extract of leaves of Eremophila galeata , a plant endemic to Australia, was investigated for inhibitory activity of parental (HT29 par ) as well as BCRP-overexpressing HT29 colon cancer cells resistant to the chemotherapeutic SN-38 (i.e., HT29 SN38 cells). This identified a fraction, eluted with 40% acetonitrile on a solid-phase extraction column, which showed weak growth-inhibitory activity on HT29 SN38 cells when administered alone, but exhibited concentration-dependent growth inhibition when administered in combination with SN-38. The major constituent in this fraction was isolated and found to be 5,3',5'-trihydroxy-3,6,7,4'-tetramethoxyflavone ( 2 ), which at a concentration of 25 μg/mL potentiated the growth-inhibitory activity of SN-38 to a degree comparable to that of the known BCRP inhibitor Ko143 at 1 μM. A dye accumulation experiment suggested that 2 inhibits BCRP, and docking studies showed that 2 binds to the same BCRP site as SN-38. These results indicate that 2 acts synergistically with SN-38, with 2 being a BCRP efflux pump inhibitor while SN-38 inhibits topoisomerase-1. more...

To investigate the relationship between non-coding RNAs [especially circular RNAs (circRNAs)] and docetaxel resistance in breast cancer, and to find potential predictive biomarkers for taxane-containing therapies, we have performed transcriptome and microRNA (miRNA) sequencing for two established docetaxel-resistant breast cancer (DRBC) cell lines and their docetaxel-sensitive parental cell lines. Our analyses revealed differences between circRNA signatures in the docetaxel-resistant and -sensitive breast cancer cells, and discovered circRNAs generated by multidrug-resistance genes in taxane-resistant cancer cells. In DRBC cells, circABCB1 was identified and validated as a circRNA that is strongly up-regulated, whereas circEPHA3.1 and circEPHA3.2 are strongly down-regulated. Furthermore, we investigated the potential functions of these circRNAs by bioinformatics analysis, and miRNA analysis was performed to uncover potential interactions between circRNAs and miRNAs. Our data showed that circABCB1, circEPHA3.1 and circEPHA3.2 may sponge up eight significantly differentially expressed miRNAs that are associated with chemotherapy and contribute to docetaxel resistance via  the PI3K-Akt and AGE-RAGE signaling pathways. We also integrated differential expression data of mRNA, long non-coding RNA, circRNA, and miRNA to gain a global profile of multi-level RNA changes in DRBC cells, and compared them with changes in DNA copy numbers in the same cell lines. We found that Chromosome 7 q21.12-q21.2 was a common region dominated by multi-level RNA overexpression and DNA amplification, indicating that overexpression of the RNA molecules transcribed from this region may result from DNA amplification during stepwise exposure to docetaxel. These findings may help to further our understanding of the mechanisms underlying docetaxel resistance in breast cancer., Competing Interests: Author PH, FL, ZM, CG, FW, CZ, JG and LL were employed by the company BGI-Shenzhen. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Huang, Li, Mo, Geng, Wen, Zhang, Guo, Wu, Li, Brünner and Stenvang.) more...

Docetaxel-a taxane-based chemotherapeutic agent-was the first treatment to demonstrate significant improvements in overall survival in men with metastatic castration-resistant prostate cancer (mCRPC). However, the response to docetaxel is generally short-lived, and relapse eventually occurs due to the development of resistance. To explore the mechanisms of acquired docetaxel resistance in prostate cancer (PCa) and set these in the context of androgen deprivation therapy, we established docetaxel-resistant PCa cell lines, derived from the androgen-dependent LNCaP cell line, and from the LNCaP lineage-derived androgen-independent C4-2B sub-line. We generated two docetaxel-resistant LNCaPR and C4-2BR sub-lines, with IC50 values 77- and 50-fold higher than those of the LNCaP and C4-2B parental cells, respectively. We performed gene expression analysis of the matched sub-lines and found several alterations that may confer docetaxel resistance. In addition to increased expression of ABCB1, an ATP-binding cassette (ABC) transporter, and a well-known gene associated with development of docetaxel resistance, we identified genes associated with androgen signaling, cell survival, and overexpression of ncRNAs. In conclusion, we identified multiple mechanisms that may be associated with the development of taxane drug resistance in PCa. Actioning these mechanisms could provide a potential approach to re-sensitization of docetaxel-resistant PCa cells to docetaxel treatment and thereby further add to the life-prolonging effects of this drug in men with mCRPC. more...

SCO-101 (Endovion) was discontinued 20 years ago as a new drug under development against sickle cell anaemia. Data from the phase 1 studies remained unpublished. New data indicate that SCO-101 might be efficacious as add-on therapy in cancer. Thus, we report the results from the four phase 1 trials performed between 2001 and 2002. Adult volunteers received SCO-101 or placebo in four independent trials. Adverse events were recorded, and SCO-101 was determined for pharmacokinetic analysis. Ninety-two volunteers completed the trials. The most remarkable adverse effect was a transient and dose-dependent increase in unconjugated bilirubin. Plasma SCO-101 elimination was approximately log linear, with apparent oral clearances of between 315 and 2103 mL/h for single doses, and between 121 and 2433 mL/h at steady state following oral administration. There was a marked decrease in clearance with increasing dose, and for repeated dose versus single dose. T max was greater, and C max and AUC ∞ were lower in the fed state compared to the fasted state. Exposure was equivalent in males and females and for African Americans and Caucasians. In conclusion, SCO-101 appears to be a safe drug with a predictable PK profile. Its efficacy as add-on to standard anticancer drugs has yet to be defined., (© 2020 The Authors. Basic & Clinical Pharmacology & Toxicology published by John Wiley & Sons Ltd on behalf of Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).) more...

In this study we investigated the use of cancer cell protein expression of ABCG2 to predict efficacy of systemic first-line irinotecan containing therapy in patients with metastatic colorectal cancer (mCRC). From a Danish national cohort, we identified 119 mCRC patients treated with irinotecan containing therapy in first-line setting. Among these, 108 were eligible for analyses. Immunohistochemistry (IHC) analyses were performed on the primary tumor tissue in order to classify samples as high or low presence of ABCG2 protein. Data were then associated with patient outcome (objective response (OR), progression free survival (PFS) and overall survival (OS)). ABCG2 protein expression in the basolateral membrane was high (score 3+) in 33% of the patients. Exploratory analyses revealed a significant interaction between ABCG2 score, adjuvant treatment and OR ( p = 0.041) in the 101 patients with evaluable disease. Patients with low ABCG2 (score 0-2) and no prior adjuvant therapy had a significantly higher odds ratio of 5.6 (Confidence Interval (CI) 1.68-18.7; p = 0.005) for obtaining OR. In contrast, no significant associations between ABCG2 expression and PFS or OS were found. These results suggest that measurement of the ABCG2 drug efflux pump might be used to select patients with mCRC for irinotecan treatment. However, additional studies are warranted before conclusions regarding a clinical use can be made. Moreover, patients with high ABCG2 immunoreactivity could be candidates for specific ABCG2 inhibition treatment in combination with irinotecan. more...

Multiple myeloma remains a hard-to-treat cancer as all patients eventually progress because of drug resistance. Thus, there is a need for novel and non-cross-resistant treatment options, and we aimed to address this issue by introducing a new immuno-oncology drug (APO010) in multiple myeloma treatment. APO010 is a hexameric Fas-ligand that mimics cytotoxic T-lymphocyte signaling through the Fas-receptor to induce apoptosis. APO010 is currently in clinical trials with multiple myeloma patients. Thus, an understanding of the mechanisms contributing to resistance to APO010 will be essential for future clinical studies with APO010, and it might be possible to develop strategies to circumvent this resistance. We developed APO010-resistant variants of human multiple myeloma cell lines (LP1, MOLP-8, and KMS-12-BM) and a human Burkitt's lymphoma cell line (Raji) by exposing the cells to gradually increasing concentrations of APO010 over a period of 6-12 months. The resistant cell lines were characterized on the basis of immunocytochemistry, Fas-receptor protein expression, mRNA expression analysis, and pathway analysis. APO010-resistant cell lines exhibited a 4- to 520-fold increase in resistance to APO010 and still remained sensitive to other chemotherapeutics. Downregulation of the Fas-receptor protein expression was observed in all resistant cell lines. mRNA expression analysis of the resistant versus parental cell lines confirmed a significant alteration in FAS expression between sensitive and resistant cell lines (p = 0.03), while pathway analysis revealed alterations in mRNA signaling pathways of Fas. On the basis of the pre-clinical data obtained, it can be concluded that downregulation of Fas-receptor can mediate resistance to APO010., (Copyright © 2020 ISEH -- Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.) more...

One of the primary barriers in treating cancer patients is the development of resistance to the available treatments. This is the case for treatment of triple negative breast cancer (TNBC) with docetaxel, which is part of the neoadjuvant treatment for TNBC. The novel compound SCO-101 is under investigation for its potential treatment effect in several types of drug resistant cancer. The aim of this study was to establish a pharmacodynamic model that captures the effect of docetaxel, SCO-101, and the combination on cell survival in docetaxel resistant MDA-MB-231 TNBC cells. Several combination models were compared and a recently published combination model, the general pharmacodynamic interaction model (GPDI), provided the best fit. The model allowed for description and quantification of the interaction between docetaxel and SCO-101 with respects to both maximal effect and potency. Based on this model, SCO-101 has a synergistic effect with docetaxel. This synergy is not present in the maximal effect, but the combination of SCO-101 and docetaxel showed an approximately 60% increase in potency compared to docetaxel alone. Furthermore, the predicted model surface for the combination provided key information regarding promising dose ratios and dose levels for further studies of the combination. Lastly, the study presents a use case for the GPDI model, which provides a way to quantify and interpret drug-drug interactions., Competing Interests: Declaration of Competing Interest Asbjørn Nøhr-Nielsen was funded by Novo Nordisk A/S. Novo Nordisk A/S had no role in the design or conduct of the study, collection, management, analysis, or interpretation of data or in preparation of the manuscript. Nils Brünner and Jan Stenvang are co-founders of Scandion Oncology, which owns the rights to SCO-101. No other authors declared any conflict of interest., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.) more...

Biomarker-guided treatment for patients with colon cancer is needed. We tested ABCG2 and topoisomerase 1 (TOP1) mRNA expression as predictive biomarkers for irinotecan benefit in the PETACC-3 patient cohort. The present study included 580 patients with mRNA expression data from Stage III colon cancer samples from the PETACC-3 study, which randomized the patients to Fluorouracil/leucovorin (5FUL) +/- irinotecan. The primary end-points were recurrence free survival (RFS) and overall survival (OS). Patients were divided into one group with high ABCG2 expression (above median) and low TOP-1 expression (below 75 percentile) ("resistant") ( n = 216) and another group including all other combinations of these two genes ("sensitive") ( n = 364). The rationale for the cut-offs were based on the distribution of expression levels in the PETACC-3 Stage II set of patients, where ABCG2 was unimodal and TOP1 was bimodal with a high expression level mode in the top quarter of the patients. Cox proportional hazards regression was used to estimate the hazard ratios and the association between variables and end-points and log-rank tests to assess the statistical significance of differences in survival between groups. Kaplan-Meier estimates of the survival functions were used for visualization and estimation of survival rates at specific time points. Significant differences were found for both RFS (Hazard ratio (HR): 0.63 (0.44-0.92); p = 0.016) and OS (HR: 0.60 (0.39-0.93); p = 0.02) between the two biomarker groups when the patients received FOLFIRI (5FUL+irinotecan). Considering only the Microsatellite Stable (MSS) and Microsatellite Instability-Low (MSI-L) patients ( n = 470), the differences were even more pronounced. In contrast, no significant differences were observed between the groups when patients received 5FUL alone. This study shows that the combination of ABCG2 and TOP1 gene expression significantly divided the Stage III colon cancer patients into two groups regarding benefit from adjuvant treatment with FOLFIRI but not 5FUL. more...