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

AbstractResistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer is a major clinical problem with poorly understood mechanisms. There is an unmet need for prognostic and predictive biomarkers to allow appropriate therapeutic targeting. We evaluated the mechanism by which minichromosome maintenance protein 3 (MCM3) influences endocrine resistance and its predictive/prognostic potential in ER+ breast cancer. We discovered that ER+ breast cancer cells survive tamoxifen and letrozole treatments through upregulation of minichromosome maintenance proteins (MCMs), including MCM3, which are key molecules in the cell cycle and DNA replication. Lowering MCM3 expression in endocrine-resistant cells restored drug sensitivity and altered phosphorylation of cell cycle regulators, including p53(Ser315,33), CHK1(Ser317), and cdc25b(Ser323), suggesting that the interaction of MCM3 with cell cycle proteins is an important mechanism of overcoming replicative stress and anti-proliferative effects of endocrine treatments. Interestingly, the MCM3 levels did not affect the efficacy of growth inhibitory by CDK4/6 inhibitors. Evaluation of MCM3 levels in primary tumors from four independent cohorts of breast cancer patients receiving adjuvant tamoxifen mono-therapy or no adjuvant treatment, including the Stockholm tamoxifen (STO-3) trial, showed MCM3 to be an independent prognostic marker adding information beyond Ki67. In addition, MCM3 was shown to be a predictive marker of response to endocrine treatment. Our study reveals a coordinated signaling network centered around MCM3 that limits response to endocrine therapy in ER+ breast cancer and identifies MCM3 as a clinically useful prognostic and predictive biomarker that allows personalized treatment of ER+ breast cancer patients.

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Fatty Acid Synthase Confers Tamoxifen Resistance to ER+/HER2+ Breast Cancer

Cancers ◽

10.3390/cancers13051132 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1132

Author(s):

Javier A. Menendez ◽

Adriana Papadimitropoulou ◽

Travis Vander Steen ◽

Elisabet Cuyàs ◽

Bharvi P. Oza-Gajera ◽

...

Keyword(s):

Breast Cancer ◽

Fatty Acid ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Promoter Activity ◽

Fatty Acid Synthase ◽

Endocrine Resistance ◽

Gene Promoter ◽

Her2 Positive ◽

Her2 Breast Cancer

The identification of clinically important molecular mechanisms driving endocrine resistance is a priority in estrogen receptor-positive (ER+) breast cancer. Although both genomic and non-genomic cross-talk between the ER and growth factor receptors such as human epidermal growth factor receptor 2 (HER2) has frequently been associated with both experimental and clinical endocrine therapy resistance, combined targeting of ER and HER2 has failed to improve overall survival in endocrine non-responsive disease. Herein, we questioned the role of fatty acid synthase (FASN), a lipogenic enzyme linked to HER2-driven breast cancer aggressiveness, in the development and maintenance of hormone-independent growth and resistance to anti-estrogens in ER/HER2-positive (ER+/HER2+) breast cancer. The stimulatory effects of estradiol on FASN gene promoter activity and protein expression were blunted by anti-estrogens in endocrine-responsive breast cancer cells. Conversely, an AKT/MAPK-related constitutive hyperactivation of FASN gene promoter activity was unaltered in response to estradiol in non-endocrine responsive ER+/HER2+ breast cancer cells, and could be further enhanced by tamoxifen. Pharmacological blockade with structurally and mechanistically unrelated FASN inhibitors fully impeded the strong stimulatory activity of tamoxifen on the soft-agar colony forming capacity—an in vitro metric of tumorigenicity—of ER+/HER2+ breast cancer cells. In vivo treatment with a FASN inhibitor completely prevented the agonistic tumor-promoting activity of tamoxifen and fully restored its estrogen antagonist properties against ER/HER2-positive xenograft tumors in mice. Functional cancer proteomic data from The Cancer Proteome Atlas (TCPA) revealed that the ER+/HER2+ subtype was the highest FASN protein expressor compared to basal-like, HER2-enriched, and ER+/HER2-negative breast cancer groups. FASN is a biological determinant of HER2-driven endocrine resistance in ER+ breast cancer. Next-generation, clinical-grade FASN inhibitors may be therapeutically relevant to countering resistance to tamoxifen in FASN-overexpressing ER+/HER2+ breast carcinomas.

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Identification and Roles of miR-29b-1-3p and miR29a-3p-Regulated and Non-Regulated lncRNAs in Endocrine-Sensitive and Resistant Breast Cancer Cells

Cancers ◽

10.3390/cancers13143530 ◽

2021 ◽

Vol 13 (14) ◽

pp. 3530

Author(s):

Penn Muluhngwi ◽

Carolyn M. Klinge

Keyword(s):

Breast Cancer ◽

Cancer Survival ◽

Expression Patterns ◽

Endocrine Resistance ◽

Estrogen Receptor Α ◽

Resistant Cell ◽

Differentially Expressed ◽

Primary Tumors ◽

Non Coding Rnas ◽

Mcf 7

Despite improvements in the treatment of endocrine-resistant metastatic disease using combination therapies in patients with estrogen receptor α (ERα) primary tumors, the mechanisms underlying endocrine resistance remain to be elucidated. Non-coding RNAs (ncRNAs), including microRNAs (miRNA) and long non-coding RNAs (lncRNA), are targets and regulators of cell signaling pathways and their exosomal transport may contribute to metastasis. Previous studies have shown that a low expression of miR-29a-3p and miR-29b-3p is associated with lower overall breast cancer survival before 150 mos. Transient, modest overexpression of miR-29b1-3p or miR-29a-3p inhibited MCF-7 tamoxifen-sensitive and LCC9 tamoxifen-resistant cell proliferation. Here, we identify miR-29b-1/a-regulated and non-regulated differentially expressed lncRNAs in MCF-7 and LCC9 cells using next-generation RNA seq. More lncRNAs were miR-29b-1/a-regulated in LCC9 cells than in MCF-7 cells, including DANCR, GAS5, DSCAM-AS1, SNHG5, and CRND. We examined the roles of miR-29-regulated and differentially expressed lncRNAs in endocrine-resistant breast cancer, including putative and proven targets and expression patterns in survival analysis using the KM Plotter and TCGA databases. This study provides new insights into lncRNAs in endocrine-resistant breast cancer.

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Transcriptional coregualtor NUPR1 maintains tamoxifen resistance in breast cancer cells

Cell Death and Disease ◽

10.1038/s41419-021-03442-z ◽

2021 ◽

Vol 12 (2) ◽

Author(s):

Lingling Wang ◽

Jiashen Sun ◽

Yueyuan Yin ◽

Yanan Sun ◽

Jinyi Ma ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Critical Role ◽

Endocrine Resistance ◽

Autophagic Flux ◽

Physical Interaction ◽

Premature Senescence ◽

Breast Cancers ◽

Transcriptional Coregulator

AbstractTo support cellular homeostasis and mitigate chemotherapeutic stress, cancer cells must gain a series of adaptive intracellular processes. Here we identify that NUPR1, a tamoxifen (Tam)-induced transcriptional coregulator, is necessary for the maintenance of Tam resistance through physical interaction with ESR1 in breast cancers. Mechanistically, NUPR1 binds to the promoter regions of several genes involved in autophagy process and drug resistance such as BECN1, GREB1, RAB31, PGR, CYP1B1, and regulates their transcription. In Tam-resistant ESR1 breast cancer cells, NUPR1 depletion results in premature senescence in vitro and tumor suppression in vivo. Moreover, enforced-autophagic flux augments cytoplasmic vacuolization in NUPR1-depleted Tam resistant cells, which facilitates the transition from autophagic survival to premature senescence. Collectively, these findings suggest a critical role for NUPR1 as a transcriptional coregulator in enabling endocrine persistence of breast cancers, thus providing a vulnerable diagnostic and/or therapeutic target for endocrine resistance.

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Novel Agents Show Promise Against Acquired Endocrine Resistance in ER + Advanced Breast Cancer

The Oncologist ◽

10.1002/onco.13874 ◽

2021 ◽

Keyword(s):

Breast Cancer ◽

Advanced Breast Cancer ◽

Endocrine Resistance ◽

Advanced Breast ◽

Novel Agents

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The Emerging Role of Extracellular Vesicles in Endocrine Resistant Breast Cancer

Cancers ◽

10.3390/cancers13051160 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1160

Author(s):

Giusi La Camera ◽

Luca Gelsomino ◽

Amanda Caruso ◽

Salvatore Panza ◽

Ines Barone ◽

...

Keyword(s):

Breast Cancer ◽

Endocrine Therapy ◽

Extracellular Vesicles ◽

Molecular Mechanisms ◽

Endocrine Resistance ◽

Disease Recurrence ◽

Estrogen Receptor Α ◽

Research Area ◽

Tumor Evolution

Breast cancer is the most common solid malignancy diagnosed in females worldwide, and approximately 70% of these tumors express estrogen receptor α (ERα), the main biomarker of endocrine therapy. Unfortunately, despite the use of long-term anti-hormone adjuvant treatment, which has significantly reduced patient mortality, resistance to the endocrine treatments often develops, leading to disease recurrence and limiting clinical benefits. Emerging evidence indicates that extracellular vesicles (EVs), nanosized particles that are released by all cell types and responsible for local and systemic intercellular communications, might represent a newly identified mechanism underlying endocrine resistance. Unraveling the role of EVs, released by transformed cells during the tumor evolution under endocrine therapy, is still an open question in the cancer research area and the molecular mechanisms involved should be better defined to discover alternative therapeutic approaches to overcome resistance. In this review, we will provide an overview of recent findings on the involvement of EVs in sustaining hormonal resistance in breast cancer and discuss opportunities for their potential use as biomarkers to monitor the therapeutic response and disease progression.

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The Modern Landscape of Endocrine Therapy for Premenopausal Women with Breast Cancer

Breast Care ◽

10.1159/000439462 ◽

2015 ◽

Vol 10 (5) ◽

pp. 312-315 ◽

Cited By ~ 8

Author(s):

Lorenzo Rossi ◽

Olivia Pagani

Keyword(s):

Breast Cancer ◽

Endocrine Therapy ◽

Ovarian Function ◽

Treatment Options ◽

Endocrine Resistance ◽

Premenopausal Women ◽

New Drugs ◽

Fine Tuning ◽

Individual Risk ◽

Ovarian Function Suppression

The optimal endocrine therapy for premenopausal women with early and advanced breast cancer still remains an important and controversial issue. For over 30 years, tamoxifen has been the gold standard in the adjuvant setting. New therapeutic options, such as the addition of ovarian function suppression to oral endocrine therapy (either tamoxifen or aromatase inhibitors), can improve outcomes over tamoxifen alone in well-selected patients. Treatment duration has also been revisited, and extended therapy is becoming a new standard of care, especially in high-risk patients. Endocrine therapy for advanced disease still represents a challenge and a research priority. New drugs and combinations able to overcome endocrine resistance are at the horizon, and their role in premenopausal women should be better elucidated. Side effects and quality of life (including family planning considerations) play an important role in treatment selection and in the patients' treatment adherence and should always be discussed before start of treatment. The paper will specifically focus on how to integrate all new treatment options in the current armamentarium of endocrine therapy of premenopausal women, with the aim of best fine-tuning treatment selections according to the individual risk/benefit evaluation.

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