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: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: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
Project description:The use of trastuzumab and pertuzumab in combination with docetaxel for initial treatment of HER2-positive breast cancer patients has resulted in notable clinical benefits in comparison to docetaxel administered with trastuzumab alone. Nevertheless, although therapeutic success is evident at the outset, the majority of tumours eventually advance, rendering metastatic disease and subsequent recurrence in patients who have developed acquired resistance. There is an urgent requirement to enhance our comprehension of the mechanisms governing resistance, enabling us to develop targeted therapeutic approaches to improve efficacy. We produced four HER2-positive-derived cell lines through prolonged exposure to trastuzumab and pertuzumab, determining their resistance rates. We confirmed long-term resistance through a notable increase in colony formation capacity of the derived cells. We confirmed the molecular identity of the new cell lines using immunohistochemistry of their receptors and profiling of point mutations. We detected HER2 overexpression in all cell lines and resistance to trastuzumab and pertuzumab did not result in variations in ER, PR and HER2 receptor expression. Finally, a study using proteomics analysis confirmed a significant alteration in the abundance patterns of over 600 proteins. This has implications for various vital biological processes such as ribosome creation, mitochondrial functionality, and metabolism. These mechanisms may play a crucial role in developing resistance in HER2-positive breast cancer. We conclude that these BCCLs resistant to trastuzumab plus pertuzumab-based anti-HER2 therapy could be a useful resource to enhance comprehension of resistance acquisition mechanisms.
Project description:Trastuzumab, a humanized monoclonal antibody directed to the HER2 protein, is the standard-of-care treatment for patients with HER2 positive breast cancer, reducing the risk of relapse and death in patients. Nonetheless, some patients do not benefit from this treatment, underscoring the need to identify patients for whom chemotherapy + trastuzumab is adequate versus patients requiring additional drugs. The series comprised 24 incisional biopsies of breast carcinomas derived from patients that received neoadjuvant trastuzumab based therapy. Gene expression profiling was performed using RNA from frozen core biopsies from 24 patients with primary HER2-positive (HER2+) tumors treated with neoadjuvant chemotherapy and trastuzumab.
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:Trastuzumab, a humanized monoclonal antibody directed to the HER2 protein, is the standard-of-care treatment for patients with HER2 positive breast cancer, reducing the risk of relapse and death in patients. Nonetheless, some patients relapse after treatment, underscoring the need to identify patients for whom chemotherapy + trastuzumab is adequate versus patients requiring additional drugs. To search for genes predictive of relapse in HER2-positive breast carcinoma patients treated with adjuvant trastuzumab, we conducted gene expression profiling analysis in 53 cases treated in the clinic with doxorubicin/paclitaxel (AT) followed by cyclophosphamide/methotrexate/fluorouracil (CMF) and trastuzumab. Gene expression profiling was performed using RNA from formalin-fixed paraffin-embedded tissues from 53 patients with primary HER2-positive (HER2+) tumors. The series consists in 23 relapsed and 30 non-relapsed cases with similar clinical-pathological characteristics (size, pathological lymph node involvement and estrogen receptor positivity) (3-year median follow up).