Project description:Purpose: Transcriptome analysis of ESR1 mutant cells was performed via sequencing total RNA in T47D and MCF7 cell lines containing Y537S and D538G mutations.
Project description:The rediscovery of estrogen receptor (ESR1) mutations in metastatic breast cancer is current clinical scenario. We have modeled the three most frequent ESR1 mutations using stable lentiviral vectors in human breast cancer cell lines, and determined that they confer relative resistance to tamoxifen (Tam) in a cell-type specific manner due to distinct epigenetic changes. Resistance was only observed with concomitant engagement and activation of the insulin growth factor signaling pathway (IGF1R). The ESR1 mutants also exhibited enhanced binding with insulin growth factor receptor beta (IGF1Rβ). The selective estrogen degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while the combination treatment with the mTOR inhibitor everolimus, restored Tam sensitivity. Since we detected relatively high frequencies of these three mutations in primary breast tumors, our results suggest that clinical targeted sequencing of both primary and metastatic tumors may be justified and comination therapies considered.
Project description:Estrogen insensitivity syndrome (EIS) arises from rare mutations in estrogen receptor α (ERα, encoded by ESR1 gene) resulting in the inability of estrogen to exert its biological effects. Due to the rarity, mutations in ESR1 gene and the underlying molecular mechanisms of EIS have not been thoroughly studied. We used human EPIC DNA methylation array to comparison of the transcriptome between the WT ESR1 and Q375H and R394H clinical mutants in MB231 stable cell lines.
Project description:We report the first discovery of naturally occurring ESR1Y537C and ESR1Y537S mutations in MCF7 and SUM44 ESR1-positive cell-lines after acquisition of resistance to long-term-estrogen-deprivation (LTED) and subsequent resistance to fulvestrant (ICIR).
Project description:We report the first discovery of naturally occurring ESR1Y537C and ESR1Y537S mutations in MCF7 and MCF7 ESR1-positive cell-lines after acquisition of resistance to long-term-estrogen-deprivation (LTED) and subsequent resistance to fulvestrant (ICIR).
Project description:Three quarters of all breast cancer cases express the estrogen receptor (ER, ESR1 gene), which promotes tumor growth and constitutes a direct target for endocrine therapies. ESR1 mutations have been implicated in therapy resistance in metastatic breast cancers, in particular to aromatase inhibitors. ESR1 mutations promote constitutive ER activity and affect other signaling pathways, allowing cancer cells to proliferate by employing mechanisms within and outwith direct regulation by the ER. Although subjected to extensive genetic and transcriptomic analyses, understanding of protein alterations remains poorly investigated. Towards this, we employed an integrated mass spectrometry (MS) based proteomic approach to profile the protein and phosphoprotein differences in breast cancer cell lines expressing the frequent Y537N and Y537S ER mutations. Global proteome analysis revealed enrichment of mitotic and immune signaling pathways in ER mutant cells, while phosphoprotein analysis evidenced enriched activity of proliferation associated kinases, in particular CDKs and MTOR. Integration of protein expression and phosphorylation data revealed pathway-dependent discrepancies (motility vs proliferation) that were observed at varying degrees across mutant and wt ER cells. Additionally, protein expression and phosphorylation patterns, while under different regulation, still recapitulated the estrogen-independent phenotype of ER mutant cells.
Project description:Three quarters of all breast cancer cases express the estrogen receptor (ER, ESR1 gene), which promotes tumor growth and constitutes a direct target for endocrine therapies. ESR1 mutations have been implicated in therapy resistance in metastatic breast cancers, in particular to aromatase inhibitors. ESR1 mutations promote constitutive ER activity and affect other signaling pathways, allowing cancer cells to proliferate by employing mechanisms within and outwith direct regulation by the ER. Although subjected to extensive genetic and transcriptomic analyses, understanding of protein alterations remains poorly investigated. Towards this, we employed an integrated mass spectrometry (MS) based proteomic approach to profile the protein and phosphoprotein differences in breast cancer cell lines expressing the frequent Y537N and Y537S ER mutations. Global proteome analysis revealed enrichment of mitotic and immune signaling pathways in ER mutant cells, while phosphoprotein analysis evidenced enriched activity of proliferation associated kinases, in particular CDKs and MTOR. Integration of protein expression and phosphorylation data revealed pathway-dependent discrepancies (motility vs proliferation) that were observed at varying degrees across mutant and wt ER cells. Additionally, protein expression and phosphorylation patterns, while under different regulation, still recapitulated the estrogen-independent phenotype of ER mutant cells.
Project description:The goal of the study was to understand whether mutations in ERa can promote resistance to various ERa antagonists of the SERD and SERM class. We found that ESR1 mutations can maintain higher ER pathway activity relative to control lines following short-term treatment with ERa antagonists raloxifene or fulvestrant.
Project description:Three quarters of all breast cancer cases express the estrogen receptor (ER, ESR1 gene), which promotes tumor growth and constitutes a direct target for endocrine therapies. ESR1 mutations have been implicated in therapy resistance in metastatic breast cancers, in particular to aromatase inhibitors. ESR1 mutations promote constitutive ER activity and affect other signaling pathways, allowing cancer cells to proliferate by employing mechanisms within and outwith direct regulation by the ER. Although subjected to extensive genetic and transcriptomic analyses, understanding of protein alterations remains poorly investigated. Towards this, we employed an integrated mass spectrometry (MS) based proteomic approach to profile the protein and phosphoprotein differences in breast cancer cell lines expressing the frequent Y537N and Y537S ER mutations. Global proteome analysis revealed enrichment of mitotic and immune signaling pathways in ER mutant cells, while phosphoprotein analysis evidenced enriched activity of proliferation associated kinases, in particular CDKs and MTOR. Integration of protein expression and phosphorylation data revealed pathway-dependent discrepancies (motility vs proliferation) that were observed at varying degrees across mutant and wt ER cells. Additionally, protein expression and phosphorylation patterns, while under different regulation, still recapitulated the estrogen-independent phenotype of ER mutant cells.