Project description:Lymph node status is a crucial predictor for the overall survival of invasive breast cancer. However, lymph node involvement is only detected in about half of HER2 positive patients. Currently, there are no biomarkers available for distinguishing small size HER2-positive breast cancers with different lymph node statuses. Thus, in the present study, we applied label-free quantitative proteomic strategy to construct plasma proteomic profiles of ten patients with small size HER2-positive breast cancers (5 patients with lymph node metastasis versus 5 patients with lymph node metastasis).
Project description:Forkhead box protein A1 (FOXA1) has been shown to have critical functions in prostate and ER alpha positive breast cancer. As a pioneering transcriptional factor, FOXA1 regulates DNA accessibility for the androgen receptor in prostate and the estrogen receptor alpha in ER positive breast cancer, respectively. FOXA1 is also expressed in human epidermal growth factor receptor-2 (HER2/ErbB2) positive breast cancers, but its functions in HER2 positive breast cancer are unclear. The loss of FOXA1 results in a decrease in the viability of HER2 positive and HER2 amplified cell lines suggesting that FOXA1 may have an important role in HER2 positive breast cancers. In this report, we examined patient-derived single-cell RNA sequencing and spatial transcriptomics data and demonstrated that FOXA1 is co-expressed with ErbB2 in HER2 positive breast cancers. Knocking down FOXA1 expression led to the reduction of HER2 expression and signaling. Chromatin Immunoprecipitation Sequencing (ChIP-seq) and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) identified FOXA1 binding motifs in the ErbB2 promoter and regulatory element regions, which controlled ErbB2 gene expression. Interestingly, the knockdown of FOXA1 increased Epithelial Mesenchymal Transition (EMT) signaling and inhibited luminal tumor differentiation. Furthermore, FOXA1 and TRPS1 regulated TEAD/YAP-TAZ activity. Taken together, our data demonstrate that FOXA1 is required for HER2 expression and luminal identity in HER2+ breast cancer.
Project description:Forkhead box protein A1 (FOXA1) has been shown to have critical functions in prostate and ER alpha positive breast cancer. As a pioneering transcriptional factor, FOXA1 regulates DNA accessibility for the androgen receptor in prostate and the estrogen receptor alpha in ER positive breast cancer, respectively. FOXA1 is also expressed in human epidermal growth factor receptor-2 (HER2/ErbB2) positive breast cancers, but its functions in HER2 positive breast cancer are unclear. The loss of FOXA1 results in a decrease in the viability of HER2 positive and HER2 amplified cell lines suggesting that FOXA1 may have an important role in HER2 positive breast cancers. In this report, we examined patient-derived single-cell RNA sequencing and spatial transcriptomics data and demonstrated that FOXA1 is co-expressed with ErbB2 in HER2 positive breast cancers. Knocking down FOXA1 expression led to the reduction of HER2 expression and signaling. Chromatin Immunoprecipitation Sequencing (ChIP-seq) and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) identified FOXA1 binding motifs in the ErbB2 promoter and regulatory element regions, which controlled ErbB2 gene expression. Interestingly, the knockdown of FOXA1 increased Epithelial Mesenchymal Transition (EMT) signaling and inhibited luminal tumor differentiation. Furthermore, FOXA1 and TRPS1 regulated TEAD/YAP-TAZ activity. Taken together, our data demonstrate that FOXA1 is required for HER2 expression and luminal identity in HER2+ breast cancer.
Project description:Forkhead box protein A1 (FOXA1) has been shown to have critical functions in prostate and ER alpha positive breast cancer. As a pioneering transcriptional factor, FOXA1 regulates DNA accessibility for the androgen receptor in prostate and the estrogen receptor alpha in ER positive breast cancer, respectively. FOXA1 is also expressed in human epidermal growth factor receptor-2 (HER2/ErbB2) positive breast cancers, but its functions in HER2 positive breast cancer are unclear. The loss of FOXA1 results in a decrease in the viability of HER2 positive and HER2 amplified cell lines suggesting that FOXA1 may have an important role in HER2 positive breast cancers. In this report, we examined patient-derived single-cell RNA sequencing and spatial transcriptomics data and demonstrated that FOXA1 is co-expressed with ErbB2 in HER2 positive breast cancers. Knocking down FOXA1 expression led to the reduction of HER2 expression and signaling. Chromatin Immunoprecipitation Sequencing (ChIP-seq) and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) identified FOXA1 binding motifs in the ErbB2 promoter and regulatory element regions, which controlled ErbB2 gene expression. Interestingly, the knockdown of FOXA1 increased Epithelial Mesenchymal Transition (EMT) signaling and inhibited luminal tumor differentiation. Furthermore, FOXA1 and TRPS1 regulated TEAD/YAP-TAZ activity. Taken together, our data demonstrate that FOXA1 is required for HER2 expression and luminal identity in HER2+ breast cancer.
Project description:Some HER2 positive breast cancer patients are refractory to trastuzumab therapy. MicroRNAs have been used to predict therapeutic effects for various cancers, and our study suggests that the serum-based miRNA signature can effectively distinguish HER2+ MBC patients who are sensitive to trastuzumab from those are resistant.
Project description:Alterations in the histone methylation profiles are observed in various types of cancer and targeting of this epigenetic process has therapeutic potential. Here we provide proof-of-principle that pharmacological targeting of KDM5 histone-demethylases is a new strategy for the personalized treatment of HER2-positive breast cancer. This analysis demonstrates that cells characterized by HER2-positivity are particularly sensitive to KDM5 inhibition. The results are confirmed in an appropriate in vivo model with a close structural analogue (KDM5-inh1A). In selected HER2-positive breast cancer cells, we demonstrate synergistic interactions between KDM5-inh1 and HER2-targeting agents (trastuzumab and lapatinib). In addition, HER2-positive cell lines showing innate/acquired resistance to trastuzumab show sensitivity to KDM5-inh1. The levels of KDM5A/B/C proteins, which are selectively targeted by the agent, have no significant association with KDM5-inh1 responsiveness across our panel of breast cancer cell lines, suggesting the existence of other determinants of sensitivity. Using RNA-sequencing data of the breast cancer cell lines, we generate a gene-expression model, consisting of fifteen genes, which is a robust predictor of KDM5-inh1 sensitivity. In a test set of breast cancers, this model correctly predicts sensitivity to the compound in a large fraction of HER2+ tumors. In conclusion, KDM5 inhibition has potential in the treatment of HER2+ breast cancer and our gene-expression model can be developed into a diagnostic tool to select patients who may benefit from treatments based on KDM5-inhibitors.
Project description:The goal of our study is to build an integrated transcriptome landscape model for HER2 positive breast tumors and identify the crucial signaling pathways associated with HER2 tumors. Genomic features include, 685 genes that were differentially expressed only in HER2-positive tumors, 102 genes that were alternatively spliced in a pattern that is unique to HER2-positive tumors, and 303 genes that expressed single nucleotide sequence variants (eSNVs) that were unique to HER2-positive tumors. Network analysis was performed to integrate the genomic features into a transcriptome landscape model that identified 12 highly interconnected cellular processes that appear to be critical to the establishment and maintenance of HER2-positive tumors. We observed that integrin signaling was linked to lapatinib sensitivity in vitro and strongly associated with risk of relapse in the NCCTG N9831 adjuvant trastuzumab clinical trial dataset. We analyzed RNA-seq data from a survey panel consisting of 8 benign breast lesions, 8 ER+, 8 triple negative, and 8 HER2-positive primary breast tumors to identify genomic features that were uniquely associated with HER2-positive tumors
Project description:Hormones and growth factors accelerate cell proliferation of breast cancer cells, and these molecules are well investigated targets for drug development and application. The mechanisms of cell proliferation of breast cancers lacking estrogen receptor (ER) and HER2 have not been fully understood. The purpose of the present study is to find genes that are differentially expressed in breast cancers and that might significantly contribute to cell proliferation in these cancers. Forty tumor samples, consisting of ten each of immunohistochemically ER(+)/HER2(-), ER(+)/HER2(+), ER(-)/HER2(+), and ER(-)/HER2(-) cancer were analyzed using oligonucleotide microarrays. Both genes and tumor samples were subjected to hierarchical clustering. ER(+)/HER2(-) breast cancers and ER(-)/HER2(-) cancers tended to form a tumor cluster, but HER2 positive breast cancers were split into different tumor clusters. Significant differential expression between IHC-ER(-)/HER2(-) and other tumors was defined as having an expression level at least 2-fold higher or 2-fold lower, and analyzed by multi-step two-way ANOVA. Genes overexpressed differently in IHC-ER(-)/HER2(-) breast cancers compared to other all three types were 8 genes (FABP7, GABRP, GAL, CXCL13, CDC42EP4, C2F, FOXM1, CSDA), and underexpressed genes were nine including ITGB5, KIAA0310, MAGED2, PRSS11, SORL1, TGFB3, KRT18, CPE, BCAS1. No gene was directly related to cell proliferation such as cyclins, cyclin-dependent kinase, p53, p16, and the pRb and p21 families. We had a particular focus on a transcriptional factor E2F-5 from a list of genes overexpressed in ER negative breast cancers compared to ER positive breast cancers, and further examined. Gene amplification of E2F-5 was detected in 5/57 (8.8%) in breast cancers by FISH. No point mutation was found at the binding domain with DNA or dimerization partner of E2F-5. Immunohistochemically E2F-5 positive cancers were more frequent in ER(-)/HER2(-) cancer (14/27, 51.9%) than in other types of cancer (5/30, 16.7%) (p=0.05). E2F-5 positive cancers had higher Ki-67 labeling index (59.5%) than E2F-5 negative cancers (36.3%). E2F-5 positive cancers showed higher histological grade including metaplastic carcinoma, and worse clinical outcome with shorter disease free survival in node negative patients. In conclusion, we demonstrated that there is a population of breast cancer with overexpression of a cell cycle related transcriptional factor E2F-5. E2F-5 positive breast cancers were frequent in ER(-)/HER2(-) group with high Ki-67 labeling index, high histological grade and worse clinical outcome. Keywords: immunohistochemical phenotype
Project description:Conditioned medium experiments carried out in our laboratory with CAFs derived from HER2-positive patients showed a significant capacity to promote resistance to trastuzumab plus pertuzumab therapies in two HER2-positive breast cancer cell lines (BCCLs), even in the presence of docetaxel. In order to elucidate the components of CAF-conditioned medium that would be relevant in the promotion of BCCL resistance, we performed a multi-omics strategy to identify miRNAs, cytokines, transcription factors and/or kinases in the secretome that target specific objectives in cancer cells. The combination of miRNA analysis, label-free LC-MS/MS quantification and cytokine arrays to explore the secretome of CAFs under treatment conditions revealed several up- and down-regulated candidates. We discuss the potential role of some of the most interesting candidates in generating resistance in HER2-positive breast cancer