Evolution of resistance in ER+ Breast Cancer
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PROVIDER: PRJNA678034 | ENA |
REPOSITORIES: ENA
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Project description:Evolution of resistance in ER+ Breast Cancer
| PRJNA678035 | ENA
Project description:Estrogen receptor positive (ER+) breast cancers that develop resistance to therapies that target the ER are the most common cause of breast cancer death. Beyond mutations in ER, which occur in 25-30% of patients treated with aromatase inhibitors (AIs), our understanding of clinical mechanisms of resistance to ER-directed therapies remains incomplete. We identified activating HER2 mutations in metastatic biopsies from eight patients with ER+ metastatic breast cancer who had developed resistance to ER-directed agents, including AIs, tamoxifen, and fulvestrant. Examination of treatment-naïve primary tumors in five patients revealed no evidence of pre-existing mutations in four of five patients, suggesting that these mutations were acquired under the selective pressure of ER-directed therapy. These mutations were mutually exclusive with ER mutations, suggesting a distinct mechanism of acquired resistance to ER-directed therapies. In vitro analysis confirmed that these mutations conferred estrogen independence. In addition, and in contrast to ER mutations, these mutations resulted in resistance to tamoxifen, fulvestrant, and the CDK4/6 inhibitor palbociclib. Resistance was overcome by combining ER-directed therapy with the irreversible HER2 kinase inhibitor neratinib, highlighting an effective treatment strategy in these patients.
2018-10-19 | GSE121411 | GEO
Project description:Response and Resistance to ER-directed Therapy in ER+ Metastatic Breast Cancer
| PRJNA369715 | ENA
Project description:Beyond acquired mutations in the estrogen receptor (ER), mechanisms of resistance to ER-directed therapies in ER+ breast cancer have not been clearly defined. We conducted a genome-scale functional screen spanning 10,135 genes to investigate genes whose overexpression confer resistance to selective estrogen receptor degraders. Pathway analysis of candidate resistance genes demonstrated that the FGFR, ERBB, insulin receptor, and MAPK pathways represented key modalities of resistance. In parallel, we performed whole exome sequencing in paired pre-treatment and post-resistance biopsies from 60 patients with ER+ metastatic breast cancer who had developed resistance to ER-targeted therapy. The FGFR pathway was altered via FGFR1, FGFR2, or FGF3/FGF4 amplifications or FGFR2 mutations in 24 (40%) of the post-resistance biopsies. In 12 of the 24 post-resistance tumors exhibiting FGFR/FGF alterations, these alterations were not detected in the corresponding pre-treatment tumors, suggesting that they were acquired or enriched under the selective pressure of ER-directed therapy. In vitro experiments in ER+ breast cancer cells confirmed that FGFR/FGF alterations led to fulvestrant resistance as well as cross-resistance to the CDK4/6 inhibitor palbociclib, through activation of the MAPK pathway. The resistance phenotypes were reversed by FGFR inhibitors and, to a lesser extent, MEK inhibitors, suggesting potential treatment strategies.
2020-06-30 | GSE153509 | GEO
Project description:While targeted therapies directed against cancer cells have proven effective, their clinical benefit is often limited by acquired resistance. This clinical challenge underscores the importance of uncovering the molecular mechanisms behind resistance in order to develop novel targets and drug combinations that can stop the growth of cancer cells. Two pivotal pathways controlling tumor growth are glucose metabolism and cell cycle. PFKFB3 and CDK4/6 are key regulators of glucose metabolism and cell cycle respectively for which inhibitors have been developed. PFK158 is an inhibitor against PFKFB3 that is currently undergoing phase I clinical trials and has shown to be effective at blocking glucose metabolism in solid tumors. Palbociclib, a novel CDK4/6 inhibitor was recently approved as a first-line approach for the treatment of estrogen receptor (ER) positive breast cancer because of the very promising clinical responses in ER+ breast cancer patients. Unfortunately, the effects of these therapies are short-lasting since cancer cells ultimately develop resistance allowing them to escape treatment. To identify the molecular mechanisms driving resistance to PFK158 or palbociclib, we have generated ER+ MCF7 and ER- MDA-MB231 cells resistant to either PFK158 or palbociclib by continuous exposure to increasing doses of drugs for a period of three months. Our hypothesis is that resistance is driven by activating mutations and/or pathways acquired during the course of treatment. This study is designed to identify specific mutations and/or changes in gene expression responsible for the resistance to PFK158 or palbociclib in ER+ and ER- in vitro. The results of this study will lead to the development of new therapeutic strategies to overcome resistance to PFKFB3 and CDK4/6 inhibitors.
2019-06-20 | GSE130437 | GEO
Project description:RNA Expression Profiling Comparing ER+ Postpartum Breast Cancer with ER+ Nulliparous Breast Cancer
| PRJNA666701 | ENA
Project description:Acquired HER2 mutations in ER+ metastatic breast cancer confer resistance to ER-directed therapies
| PRJNA497449 | ENA
Project description:The molecular mechanisms underlying estrogen receptor (ER)-positive breast carcinogenesis and drug resistance remain incompletely understood. Elevated expression of CCND1 is linked to enhanced invasiveness, poorer prognosis, and resistance to drug therapies in ER-positive breast cancer. In this study, we report that a highly expressed circular RNA (circRNA) derived from FOXK2, called circFOXK2, stabilizes CCND1 mRNA, thereby promoting cell cycle progression, cell growth, and endocrine therapy resistance in ER-positive breast cancer cells. Mechanistically, circFOXK2 binds directly to CCND1 mRNA via RNA-RNA pairing, recruiting the RNA-binding protein ELAVL1/HuR to stabilize CCND1 mRNA, thereby increasing CCND1 protein levels. Elevated CCND1 activates the CCND1-CDK4/6-p-RB-E2F signaling axis, driving the transcription of downstream E2F target genes and promoting the G1/S transition during cell cycle progression. Consequently, anti-sense oligonucleotide (ASO)-targeting circFOXK2 (ASO-circFOXK2) suppresses the growth of ER-positive breast cancer cells both in vitro and in vivo. Combination treatment with ASO-circFOXK2 and Tamoxifen shows synergistic effects. Moreover, ASO-circFOXK2 restores Tamoxifen sensitivity in Tamoxifen-resistant ER-positive breast cancer cells both in vitro and in vivo. The clinical relevance is underscored by the high expression of circFOXK2, which is positively correlated with that CCND1 expression in ER-positive breast cancer cell lines and clinical tumor tissues. Overall, our findings reveal the critical role of circFOXK2 in stabilizing the mRNA of the oncogene CCND1 and promoting cell cycle progression, identifying circFOXK2 as a potential therapeutic target for treating ER-positive breast cancer in clinical settings.
2024-12-25 | GSE284608 | GEO
Project description:Combined CDK4/6 inhibitor (CDK4/6i) and endocrine therapy significantly improves the outcome of patients with advanced estrogen receptor-positive (ER+) breast cancer. However, resistance to this treatment and resultant disease progression remains a major clinical challenge. High expression of the receptor tyrosine kinase REarranged during Transfection (RET) has been associated with resistance to endocrine therapy in breast cancer, but the role of RET in CDK4/6i treatment response/resistance remains unexplored. To identify gene expression alterations associated with resistance to combined endocrine therapy and CDK4/6i, we performed global gene expression analysis and RNA sequencing of two ER+ breast cancer cell models resistant to this combined therapy.
2024-11-19 | GSE268699 | GEO
Project description:LiMe genes and ER-Breast cancer
| PRJNA523342 | ENA