Estrogen Receptor-positive Subtypes Research Articles

A Novel Compound from the Phenylsulfonylpiperazine Class: Evaluation of In Vitro Activity on Luminal Breast Cancer Cells.

Breast cancer (BC) is the most common cancer in women, and is characterized by its histological and molecular heterogeneity. Luminal BC is an estrogen receptor-positive subtype, with varied clinical courses. Although BC patients are eligible for hormone therapy, both early and late relapses still occur, and thus there is a demand for new cytotoxic and selective treatment strategies for these patients. In the present study, inspired by the structure of phenylsulfonylpiperazine, a series of 20 derivatives were tested in bioassays against MCF7, MDA-MB-231 and MDA-MB-453 BC cells to discover new hit compounds. After 48 h of treatment, 12 derivatives impaired cell viability and presented significant IC50 values against at least one of the tumor lineages. Overall, the luminal BC cell line MCF7 was more sensitive to treatments. Compound 3, (4-(1H-tetrazol-1-yl)phenyl)(4-((4-chlorophenyl)sulfonyl)piperazin-1-yl)methanone, was the most promising, with IC50 = 4.48 μM and selective index (SI) = 35.6 in MCF7 cells. Compound 3 also presented significant antimigratory and antiproliferative activities against luminal BC cells, possibly by affecting the expression of genes involved in the epithelial-mesenchymal transition mechanism, upregulating E-Cadherin transcripts (CDH1). Our findings suggest that phenylsulfonylpiperazine derivatives are potential candidates for the development of new therapies, especially those targeting luminal BC.

Retrospective study of transcriptomic profiling identifies Thai triple-negative breast cancer patients who may benefit from immune checkpoint and PARP inhibitors.

Triple-negative breast cancer (TNBC) is a rare and aggressive breast cancer subtype. Unlike the estrogen receptor-positive subtype, whose recurrence risk can be predicted by gene expression-based signature, TNBC is more heterogeneous, with diverse drug sensitivity levels to standard regimens. This study explored the benefit of gene expression-based profiling for classifying the molecular subtypes of Thai TNBC patients. The nCounter-based Breast 360 gene expression was used to classify Thai TNBC retrospective cohort subgroups. Their expression profiles were then compared against the previously established TNBC classification system. The differential characteristics of the tumor microenvironment and DNA damage repair signatures across subgroups were also explored. Thai TNBC cohort could be classified into four main subgroups, corresponding to the LAR, BL-2, and M subtypes based on Lehmann's TNBC classification. The PAM50 gene set classified most samples as basal-like subtypes except for Group 1. Group 1 exhibited similar enrichment of the metabolic and hormone response pathways to the LAR subtype. Group 2 shared pathway activation with the BL-2 subtype. Group 3 showed an increase in the EMT pathway, similar to the M subtype. Group 4 showed no correlation with Lehmann's TNBC. The tumor microenvironment (TME) analysis showed high TME cell abundance with increased expression of immune blockade genes in Group 2. Group 4 exhibited low TME cell abundance and reduced immune blockade gene expressions. We also observed distinct signatures of the DNA double-strand break repair genes in Group 1. Our study reported unique characteristics between the four TNBC subgroups and showed the potential use of immune checkpoint and PARP inhibitors in subsets of Thai TNBC patients. Our findings warrant further clinical investigation to validate TNBC's sensitivity to these regimens.

Nafamostat mesylate overcomes endocrine resistance of breast cancer through epigenetic regulation of CDK4 and CDK6 expression

Breast cancer is common worldwide, and the estrogen receptor-positive subtype accounts for approximately 70% of breast cancer in women. Tamoxifen and fulvestrant are drugs currently used for endocrinal therapy. Breast cancer exhibiting endocrine resistance can undergo metastasis and lead to the death of breast cancer patients. Drug repurposing is an active area of research in clinical medicine. We found that nafamostat mesylate, clinically used for patients with pancreatitis and disseminated intravascular coagulation, acts as an anti-cancer drug for endocrine-resistant estrogen receptor-positive breast cancer (ERPBC). Epigenetic repression of CDK4 and CDK6 by nafamostat mesylate induced apoptosis and suppressed the metastasis of ERPBC through the deacetylation of Histone 3 Lysine 27. A combination of nafamostat mesylate and CDK4/6 inhibitor synergistically overcame endocrine resistance in ERPBC. Nafamostat mesylate might be an essential adjuvant or alternative drug for the treatment of endocrine-resistant ERPBC due to the low cost-efficiency of the CDK4/6 inhibitor.

Mammographic and Sonographic Features of Breast Cancer in Women Before 30 Years of Age.

Breast cancer uncommonly occurs in young women, but, tends to be diagnosed at a later stage and have a poorer prognosis than in older women. Standard screening guidelines for this age group are not established and the radiologic features of breast cancer in young women are not fully studied yet, because of the low incidence. To investigate the imaging findings for breast cancer in women aged 30 years or younger and to correlate them with clinicopathologic features and immunohistochemical subtypes. The study included 52 women with surgically confirmed breast cancer. The medical records of the patients were retrospectively reviewed and the mammographic and ultrasonographic findings were evaluated according to the fifth edition of the ACR BI-RADS lexicon. Most of the tumors in this study were presented as a self-detected mass (42/52, 80.8%) and were of histologic grade III (31/43 invasive carcinoma, 72.1%) and the estrogen receptorpositive subtype (32/52, 61.5%). The most common mammographic finding was an irregular (19/24, 79.2%), indistinct (16/24, 66.7%), and hyperdense (20/24, 83.3%) mass. The ultrasonographic findings were of an irregular (32/47, 68.1%), indistinct (19/47, 40.4%), and hypoechoic/ heterogeneous (40/47, 85.1%) mass with no posterior features (34/47, 72.3%). An oval/round-shaped mass on ultrasonography was also correlated with triple-negative cancer (p=0.011). On mammography and ultrasonography, breast cancer in young women usually presents as a mass with irregular shape and indistinct margin. Some radiologic findings could be used to predict the molecular phenotype of the tumor.

Targeted Next-Generation Sequencing Identifies Actionable Targets in Estrogen Receptor Positive and Estrogen Receptor Negative Endometriod Endometrial Cancer.

Endometrioid endometrial cancer (EEC) is the commonest form of endometrial cancer and can be divided into estrogen receptor (ER) positive and negative subtypes. The mutational profiles of EEC have been shown to aid in tailoring treatment; however, little is known about the differences between the gene mutation profiles between these two subtypes. This study aims to investigate the gene mutation profile in ER positive and negative EEC, and to further elucidate the role of WHSC1 mutations in this cancer. EEC and normal endometrial tissues were obtained from 29 patients and subjected to next-generation sequencing (NGS) using Ion Ampliseq Comprehensive Cancer PanelTM targeting 409 cancer related. A total of 741 non-synonymous alterations were identified from 272 genes in ER positive subtype while 448 non-synonymous variants were identified from 221 genes in ER negative subtype. PTEN is the most frequently altered gene in ER positive subtype (64%, 7/11) while ARID1A is the most frequently altered gene in ER negative subtype (50%, 4/8). We also identified alterations in ERRB3 (36%, 4/11), GNAS (36%, 4/11), and WHSC1 (27%, 3/11) in the ER positive subtype. WHSC1 R1126H and L1268P were shown to significantly increase cell viability, proliferation, migration, and survival. In addition, reduction in ER expression sensitized EEC-1 cell with WHSC1 L1268P mutant to Fulvestrant treatment. We revealed the mutational spectra of ER positive and ER negative EEC that could lead to better understanding of the biological mechanisms of endometrial cancer and may ultimately result in improvement of treatment options and patient prognosis.

An estrogen-related lifestyle score is associated with risk of postmenopausal breast cancer in the PLCO cohort.

Healthy or unhealthy lifestyle behaviors are often adopted together. We aimed to investigate the combined effect of estrogen-related lifestyle factors on postmenopausal breast cancer risk. Data from 27,153 women enrolled in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial were used. We created an estrogen-related lifestyle score (ERLS) by incorporating a previously developed measure of estrogenic diet, alcohol intake, body mass index (BMI), and physical activity. The scores ranged from 0 to 6 with alcohol and BMI accounting for higher weights than the other factors. To evaluate the preventive possibilities of a low estrogen-related lifestyle and to be consistent with other published lifestyle scores, higher scores were set to correspond with potentially lower estrogenic lifestyle. The association between the ERLS and incident breast cancer was examined using Cox proportional hazards models. Participants with an ERLS of 4 or ≥ 5 had a 23% (HR 0.77; 95% CI 0.67-0.89) and 34% (HR 0.66; 95% CI 0.56-0.78) lower risk of breast cancer, respectively, compared to those with an ERLS ≤ 2 after multivariable adjustment. Estimates were similar when restricting to invasive cases or estrogen receptor-positive subtypes. No single lifestyle component appeared to drive the association. Our findings suggest that the combined effect of a lifestyle characterized by a low estrogenic diet, low alcohol consumption, low body weight, and high levels of physical activity are associated with a reduction in postmenopausal breast cancer risk, possibly through an influence on estrogen metabolism.

Pharmacotherapeutic Management of Breast Cancer in Elderly Patients: The Promise of Novel Agents.

As its incidence increases with age, breast cancer in elderly patients takes on a growing importance in clinical oncology practice. Management decisions are challenging because there is a lack of high-quality evidence in this heterogeneous population. Epidemiological studies have shown that breast cancer mortality does not decrease substantially in the older population compared with younger adults. Recent data suggest a phenotype somewhat different from that of younger patients, also confirmed at the molecular level. Breast cancer biology has been incompletely deciphered in this age group. New therapeutic agents continue to expand the available treatment options at every stage, and for each subtype of breast cancer. In the estrogen receptor-positive subtype, agents to overcome endocrine resistance have been introduced; CDK 4/6 and mTOR inhibitors have already been approved in this setting. In addition, more potent agents targeting the HER2 pathway are actively being trialed. Besides trastuzumab, pertuzumab, or lapatinib, new agents like neratinib or PI3K inhibitors are currently being tested in clinical trials. Finally, even though chemotherapy remains the cornerstone of the treatment of triple negative tumors, alternative promising approaches such as immunotherapy, notably antibodies against PD-1/PD-L1 or targeted therapies (PARP or androgen inhibitors), are currently being investigated in this specific subtype.

Plumbagin Enhances Tamoxifen Sensitivity and Inhibits Tumor Invasion in Endocrine Resistant Breast Cancer through EMT Regulation.

Tamoxifen is widely used as the first line drug for estrogen receptor-positive subtype which is expressed in 70% of overall breast cancer patients. However, approximately 50% of these patients develop acquired resistance after 5 years of treatment, which is characterized by tumor recurrence and metastasis. The epithelial mesenchymal transition (EMT) is an important process in breast cancer invasion. Fundamentally, targeting the EMT represents a crucial therapeutic strategy for preventing or treating breast cancer metastasis. Plumbagin (PLB) is a natural naphthoquinone with significant anticancer effects against several types of tumor cells including breast cancer. In this study, we investigated the effect of PLB on human endocrine-resistant breast cancer cell growth, invasion and the possible mechanisms underlying such actions. PLB exhibited potent cytotoxic activity at a micromolar concentration against endocrine-resistant breast cancer cells. Interestingly, a fixed low concentration of PLB and tamoxifen combination resulted in an increase in growth inhibition in endocrine-resistant cells. In addition, PLB also significantly suppressed mesenchymal biomarker expressions that govern the EMT process, resulting in attenuated metastatic capabilities. In conclusion, PLB should be developed as a pharmacological agent for the use as a single treatment or in combination for endocrine-resistant breast cancer. Copyright © 2016 John Wiley & Sons, Ltd.

G0S2 Suppresses Oncogenic Transformation by Repressing a MYC-Regulated Transcriptional Program.

Methylation-mediated silencing of G0-G1 switch gene 2 (G0S2) has been detected in a variety of solid tumors, whereas G0S2 induction is associated with remissions in patients with acute promyelocytic leukemia, implying that G0S2 may possess tumor suppressor activity. In this study, we clearly demonstrate that G0S2 opposes oncogene-induced transformation using G0s2-null immortalized mouse embryonic fibroblasts (MEF). G0s2-null MEFs were readily transformed with HRAS or EGFR treatment compared with wild-type MEFs. Importantly, restoration of G0S2 reversed HRAS-driven transformation. G0S2 is known to regulate fat metabolism by attenuating adipose triglyceride lipase (ATGL), but repression of oncogene-induced transformation by G0S2 was independent of ATGL inhibition. Gene expression analysis revealed an upregulation of gene signatures associated with transformation, proliferation, and MYC targets in G0s2-null MEFs. RNAi-mediated ablation and pharmacologic inhibition of MYC abrogated oncogene-induced transformation of G0s2-null MEFs. Furthermore, we found that G0S2 was highly expressed in normal breast tissues compared with malignant tissue. Intriguingly, high levels of G0S2 were also associated with a decrease in breast cancer recurrence rates, especially in estrogen receptor-positive subtypes, and overexpression of G0S2 repressed the proliferation of breast cancer cells in vitro. Taken together, these findings indicate that G0S2 functions as a tumor suppressor in part by opposing MYC activity, prompting further investigation of the mechanisms by which G0S2 silencing mediates MYC-induced oncogenesis in other malignancies.

Abstract A57: miR-125a-induced cellular switch elicits a response to anti-HER2 targeted therapy in breast cancer cells

Abstract Background: The EGFR/HER2 signaling network emerges as an effective therapeutic target for Her2 enriched cancers, which is known by its aggressive biological course. Nevertheless, there is evidence that the EGFR/HER2 network may play a key role not only in the HER2-enriched subtype of breast cancer, but also in the similarly aggressive basal-like subtype. We had formerly demonstrated the involvement of miR-125a-3p in the EGFR pathway in prostate cancer. We aimed to study the effect of miR-125a-3p as a potential modulator of the ERBB2/HER2 pathway in basal-like breast cancer subtype. Methods: Using qPCR we calibrated estrogen receptor (ER), ERBB2 (HER2), miR-125a-3p/5p (two isoforms) expression in three cell lines: MDA-MB-231, MCF-7 and SKBR3 (represent the basal-like subtype, ER positive subtype and HER2-enriched subtype respectively). We generated stable MDA-MB-231 cells that overexpress miR-125a-3p and control cells that overexpress scrambled miRNA. In parallel, we established an in vivo platform by injection of miR-125a-3p-overexpressing MDA-MB-231 breast cancer cells to the mammary pad of NUDE mice and evaluated traits of the induced tumors compared with scrambled miRNA-expressing cells (control mice) and response to potential targeted therapy. Results: miR-125a-3p was endogenously expressed in all cell lines, though its expression in MDA-MB-231 cells was significantly lower than in MCF-7 or in SKBR3 cells. Following transfection of cells with miR-125a-3p, MDA-MB-231 cells showed a significant increase in the expression level of ERBB2 mRNA and protein as well as a stronger immunofluorescence staining of ErbB2 than in control cells. Combined treatment of miR-125a-3p-overexpressing cells and trastuzumab induces apoptosis and reduces migration of MDA-MB-231 cells. By tracking Erbb2 internalization and its localization to the lysosoms/the functionality of erbb2 receptor, we determined that trastuzumab caused internalization of ErbB2 and a subsequent lysosomal lysis. In the experimental in vivo platform, starting one week post cells injection/tumor formation?, mice were treated twice a week, for the next 28 days, with 10 mg/Kg trastuzumab or saline as a control. Response to treatment was evaluated by measurement of the tumor size/volume by computerized tomography (CT) or calliper. Both measurements indicated that that the tumors in the miR-125a-3p group that were treated with trastuzumab were significantly smaller than in other groups. Conclusion: our results indicate that miR-125a-3p is capable of inducing a shift in the involvement of key cellular pathway - the ERBB2 pathway that may convert the cell fate and dispose it to anti-HER2 therapies. In an era of personalized medicine, our study proposes a means to enlarge the patient population that may benefit from anti-HER2 therapies. Citation Format: Lihi Ninio-Many, Elad Hikri, Salomon M. Stemmer, Ruth Shalgi, Irit Ben-Aharon. miR-125a-induced cellular switch elicits a response to anti-HER2 targeted therapy in breast cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A57.

Abstract P3-10-35: Using Automated Image Analysis To Validate Ki67 as a Clinical Prognostic Biomarker for Estrogen-Receptor Positive Breast Cancers

Abstract Background: Ki67, an indicator of proliferation, has been shown to be a useful prognostic and predictive marker for breast cancer. Ki67 can be used to identify two distinct estrogen-receptor positive subtypes: luminal A and luminal B. Luminal A breast cancers have been identified as having a lower proliferation and better outcome compared to luminal B. Furthermore, early clinical trials suggest that Ki67 may be useful in identifying a subset of patients that are sensitive to adjuvant docetaxel treatment. Currently, only estrogen-receptor (ER), progesterone-receptor (PR), and human epidermal growth-factor (HER2) are routinely performed. We have optimized and validated an immunohistochemical (IHC) Ki67 assay and automated computerized image analysis platform for routine clinical testing. Materials and Methods: Immunohistochemical staining was quantitatively assessed using the ACIS® III platform on a cohort (N=761) of tamoxifen treated patients who were diagnosed with breast cancer in Calgary between 1990 and 2001. Tissue microarrays were constructed using three 0.6 mm cores. Ki67 results were available for 510 patients, 461 of which are ER/PR positive and HER2 negative. Staining was performed using the DAKO FLEX ready-to-use system. The percent nuclear area positive was calculated using ACIS III and the maximum value was used in statistical analysis Results: X-tile statistical software was used to identify an optimal Ki67 cut point to distinguish differential overall survival in node negative ER positive cancers of 18.75%. This cut point was then used to categorize the 461 ER/PR positive and HER2 negative breast cancers into luminal A (407; 88.3%) or luminal B (54; 11.7%) subtypes. The 8-year breast cancer specific survival was 85.2% (95% CI = 81.3% - 89.1%) for luminal A and 53.6% (95% CI = 39.3% - 67.9%) for luminal B (P<0.0001). Cox regression showed a hazard ratio of 1.63 (95% CI = 0.99 — 2.67, p=0.055), adjusting for age, tumor size, grade and lymph node status. Discussion: Quantification of Ki67 expression using automated image analysis can be used clinically to distinguish luminal A from luminal B in ER/PR positive and HER2 negative breast cancers. The purpose of this project was to develop a reliable Ki67 assay that can be easily adopted by other testing centers. Using a ready-to-use IHC system — such as DAKO FLEX — allows for consistent results between other clinical laboratories. Additionally, using an automated, quantitative imaging system — such as the ACIS® III — reduces inter-observer variation that can occur by human visual assessment. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-35.