Project description:We identified the SOX4 transcription factor and integrin alpha V encoded by the ITGAV gene as important resistance mechanisms to T cell-mediated cytotoxicity of TNBC cells. Here, we performed RNA seq. analysis of SOX4 and ITGAV deficient (CRISPR knockout) BT549 human and 4T1 murine TNBC cells as compared to control edited counterparts. Additionally, we performed SOX4 specific ChIP-seq studies in BT549 human TNBC cells. The objective of the study was to identify the molecular regulators and signaling pathways that mediate resistance to T cell mediated immunity. GSEA analysis of RNA-seq data showed that the 'interferon response' represented one of the top pathways for genes upregulated in SOX4 or ITGAV edited compared to control TNBC cells. In contrast, gene sets associated with TGF beta and TNF alpha/NF kappa b were negatively enriched in both Sox4 and Itgav edited TNBC cells. Further analysis of RNA-seq data showed that SOX4 or ITGAV edited TNBC cells contained higher mRNA levels of many interferon-stimulated genes (ISGs), including genes associated with important innate immune pathways such as RIG-I/MDA-5, cGAS - STING and the AIM2 inflammasome
Project description:We identified the SOX4 transcription factor and integrin alpha V encoded by the ITGAV gene as important resistance mechanisms to T cell-mediated cytotoxicity of TNBC cells. Here, we performed RNA seq. analysis of SOX4 and ITGAV deficient (CRISPR knockout) BT549 human and 4T1 murine TNBC cells as compared to control edited counterparts. Additionally, we performed SOX4 specific ChIP-seq studies in BT549 human TNBC cells. The objective of the study was to identify the molecular regulators and signaling pathways that mediate resistance to T cell mediated immunity. GSEA analysis of RNA-seq data showed that the 'interferon response' represented one of the top pathways for genes upregulated in SOX4 or ITGAV edited compared to control TNBC cells. In contrast, gene sets associated with TGF beta and TNF alpha/NF kappa b were negatively enriched in both Sox4 and Itgav edited TNBC cells. Further analysis of RNA-seq data showed that SOX4 or ITGAV edited TNBC cells contained higher mRNA levels of many interferon-stimulated genes (ISGs), including genes associated with important innate immune pathways such as RIG-I/MDA-5, cGAS - STING and the AIM2 inflammasome
Project description:Tumor-associated macrophages (TAMs) are closely related to poor prognosis in triple-negative breast cancer (TNBC). Thus, gaining insight into how TAMs support cancer progression could contribute to effective therapies. We utilized the 4T1 murine TNBC cell line and murine bone marrow-derived macrophages to assess TAMs mediated pro-proliferative effects in vivo and in vitro. Further, Transcriptional analysis was performed to identify pathways activated in TAMs stimulated 4T1 cells. To simulate tumor microenvironment, M2 macrophages and 4T1 cells were plated into upper and lower chambers of Transwell co-culture systems respectively. we performed RNA-sequencing analysis of 4T1 cells incubated with vehicle control or M2 macrophages.
Project description:Malignant T-cell amplified sequence (MCT-1 or MCTS1) is an oncoprotein that regulates translation re-initiation, ribosomal recycling, and tumorigenicity. Given that MCT-1 amplifies interleukin-6 (IL-6) trans-signaling by elevating interaction between interleukin-6 receptor (IL-6R) and glycoprotein 130 (gp130), we aimed to dissect whether targeting IL-6R alters transcriptional profile of TNBC cells with different MCT-1 background. Through RNA-seq, we have characterized that anti-IL6R immunotherapy suppressed genes involved in cell proliferation and metastatic cascades but enriched genes associated in cell adhesion in 4T1 murine TNBC cells with shMCT-1.
Project description:Dysregulation of PI3K/Akt signaling is a dominant feature in basal-like or triple-negative breast cancers (TNBC). However, the mechanisms regulating this pathway are largely unknown in this subset of aggressive tumors. Here we demonstrate that the transcription factor SOX4 is a key regulator of PI3K signaling in TNBC. Genomic and proteomic analyses coupled with mechanistic studies identified TGFBR2 as a direct transcriptional target of SOX4 and demonstrated that TGFBR2 is required to mediate SOX4-dependent PI3K signaling. We further report that SOX4 and the SWI/SNF ATPase SMARCA4, which are uniformly overexpressed in basal-like tumors, form a previously unreported complex that is required to maintain an open chromatin conformation at the TGFBR2 regulatory regions in order to mediate TGFBR2 expression and PI3K signaling. Collectively, our findings delineate the mechanism by which SOX4 and SMARCA4 cooperatively regulate PI3K/Akt signaling and suggest that this complex may play an essential role in TNBC genesis and/or progression.
Project description:Dysregulation of PI3K/Akt signaling is a dominant feature in basal-like or triple-negative breast cancers (TNBC). However, the mechanisms regulating this pathway are largely unknown in this subset of aggressive tumors. Here we demonstrate that the transcription factor SOX4 is a key regulator of PI3K signaling in TNBC. Genomic and proteomic analyses coupled with mechanistic studies identified TGFBR2 as a direct transcriptional target of SOX4 and demonstrated that TGFBR2 is required to mediate SOX4-dependent PI3K signaling. We further report that SOX4 and the SWI/SNF ATPase SMARCA4, which are uniformly overexpressed in basal-like tumors, form a previously unreported complex that is required to maintain an open chromatin conformation at the TGFBR2 regulatory regions in order to mediate TGFBR2 expression and PI3K signaling. Collectively, our findings delineate the mechanism by which SOX4 and SMARCA4 cooperatively regulate PI3K/Akt signaling and suggest that this complex may play an essential role in TNBC genesis and/or progression. Kinase enrichment proteomic analysis was performed using HCC1143 breast cancer cells treated with a control siRNA pool or a pool targeting SOX4 in biological triplicate to evaluate the effects on the functional kinome.
Project description:MCT-1 (malignant T cell amplified sequence) is an oncoprotein encoded by Mcts1 gene that regulates translation re-initiation, ribosomal recycling, and tumorigenicity. We have characterized the metastasis cascade, immune evasion,and inflammatory responses which are suppressed by silencing of MCT-1 (shMCT-1) through transcriptional profiling of the 4T1 metastatic TNBC cell line. shMCT-1-altered gene lists are related to the IFNα-response, IFNγ-response, IL-6/JAK/STAT pathway, inflammatory response. shMCT-1 also suppresses expression of upstream regulators of PD-L1 and epidermal growth factor receptor (EGFR) ligands as compared to scramble cells.
Project description:Purpose: Compare the tumor outgrowth and immunology of an immunocompetent 4T1- and Py230-based intraductal model for triple-negative breast cancer (TNBC). Methods: BALB/c-derived 4T1 and C57BL/6-derived Py230 mammary tumor cells were side-by-side intraductally inoculated in lactating and syngeneic mice, 4T1 and Py230 primary tumors were subsequently resected at 1, 3 and 6 weeks (w) post-inoculation (p.i.), and RNA was isolated from the 4T1 and Py230 primary tumors using in house developed protocols. Results: The differentially expressed genes in the 4T1 versus Py230 primary tumor datasets at the 3 different time points were categorized into 28 hallmark gene sets using GSEA. Nine hallmarks could be related to tumor immunology and collectively showed a decreased difference in expression over time, although every immunology-related gene set remained most expressed in 4T1 primary tumors across all time points. Seven hallmarks could be related to cellular mitosis and tumor progression and were significantly upregulated at 1 w p.i. in 4T1 primary tumors, whereas at 3 w p.i. they became significantly upregulated in Py230 primary tumors, indicative for enhanced Py230 tumor proliferation. The hallmark epithelial-mesenchymal transition was significantly upregulated at 3 w p.i. in 4T1 compared to Py230 primary tumors, indicative for metastatic progression. Gene sets involved in adipose/stromal processes within the mammary gland were downregulated or weakly expressed at 1 w p.i., but became upregulated at 3 w p.i. in 4T1 compared to Py230 primary tumors, indicating that at the time 4T1 tumor cells were less proliferative compared to Py230 tumor cells, the surrounding stroma and fat tissue were more active in the 4T1- compared to the Py230-based intraductal model. The hallmark androgen response also showed a significantly upregulated expression in Py230 tumors at 3 and 6 w p.i., indicating that androgen signaling is important in invasive Py230 tumors. Conclusion: Our findings highlight an innovative 4T1- and Py230-based intraductal mouse model for TNBC with a different tumor outgrowth and associated tumor microenvironment. These differential models may broadly represent the clinically observed TNBC diversity and together provide a powerful tool to evaluate therapeutics.