Project description:TGF-betas have complex roles in tumorigenesis, with context-dependent effects that can either suppress or promote tumor progression. We have previously shown that TGF-beta has tumor suppressor activity in the MCF10Ca1h (M3) human breast cancer xenograft model. To identify potential molecular players in the tumor suppressor responses, we performed global gene expression analyses. To determine which genes were regulated by TGF-beta in this tumor model in vivo, we performed gene expression arrays on tumors derived from xenografts of M3 cells with and without expression of a dominant negative TGF-beta receptor to block activity of endogenous TGF-beta.
Project description:TGF-betas have complex roles in tumorigenesis, with context-dependent effects that can either suppress or promote tumor progression. Our goal was to use integrated genomic approaches in a model of human breast cancer progression to identify core TGF-beta-regulated genes that specifically reflect the tumor suppressor activity of TGF-beta. The model consisted of the non-tumorigenic MCF10A (“M1”), the premalignant MCF10AT1k.cl2 (“M2”), the early malignant MCF10Ca1h (“M3”) and the highly malignant, metastatic MCF10Ca1a.cl1 (“M4”) cell lines. We have previously shown that tumor suppressor activity of TGF-beta is lost in the highly malignant M4 cells. To determine how the spectrum of TGF-beta-regulated genes changes with cancer progression, we performed gene expression array analysis on four cell lines of the MCF10A-based model of breast cancer progression (M1-M4) cultured in vitro under serum-free conditions and treated with TGF-beta (5ng/ml plus condition) or vehicle (minus condition) for 1h or 6h.
Project description:TGF-betas have complex roles in tumorigenesis, with context-dependent effects that can either suppress or promote tumor progression. Our goal was to use integrated genomic approaches in a model of human breast cancer progression to identify core TGF-beta-regulated genes that specifically reflect the tumor suppressor activity of TGF-beta. The model consisted of the non-tumorigenic MCF10A (“M1”), the premalignant MCF10AT1k.cl2 (“M2”), the early malignant MCF10Ca1h (“M3”) and the highly malignant, metastatic MCF10Ca1a.cl1 (“M4”) cell lines. We have previously shown that tumor suppressor activity of TGF-beta is dependent on Smad3, and is lost in M4 cells. To identify how TGF-beta/Smad3 targets change with cancer progression, we performed promoter-wide Smad3 ChIP-chip on all four cell lines of the breast cancer progression model (M1-M4), following treatment with TGF-beta or vehicle control.
Project description:Breast cancer is hallmarked by phenotypic transitions enabling abnormal cell proliferation and invasion. The stress-protective transcription factor heat shock factor 2 (HSF2) is associated with cancer, but its function in breast carcinogenesis remains poorly understood. Analysis of human breast tumor samples and mouse in vivo xenografts uncovered that HSF2 expression and activity undergo dynamic changes as a function of tumor progression. HSF2 expression, nuclear localization, and co-expression with the proliferation marker Ki67 are increased in ductal carcinoma in situ (DCIS), suggesting that HSF2 designates hyperplastic cells underlying tumor expansion. In mouse xenografts, HSF2 localization switches from nuclear to cytoplasmic upon DCIS-to-invasive transition. Using cell-based models, we identify canonical TGF-β signaling as the molecular mechanism regulating HSF2. TGF-β-mediated downregulation of HSF2 allowed acquisition of an invasive cell phenotype, which was counteracted by ectopic HSF2. Altogether, we propose that HSF2 acts as a stage-specific switch between proliferation and invasion in breast cancer.
Project description:Tumor-derived extracellular vesicles (EVs) have been associated with cancer progression and metastasis due to the transfer of bioactive molecules in between the tumor microenvironment. Although Transforming Growth Factor-β (TGF-β) signaling associated molecules have been implicated as cargo of EVs, the role of TGF-β pathway on EV’s biology to promote tumorigenesis is poorly understood. Hence, we aimed to describe the impact of TGF-β signaling on biogenesis and functional transfer of cargo from tumor-derived EVs induced by TGF-β (EV+TGF-β1). To this end, EV-fractions enriched in CD81 or Cholerae toxin B chain (CTB) were isolated from the vesicular secretome fraction (VSF) of human breast cancer and lung adenocarcinoma cells and further characterized.
Project description:Inappropriate activation of developmental pathways is a well-recognized tumor-promoting mechanism. Here we show that overexpression of the homeoprotein Six1, normally a developmentally restricted transcriptional regulator, increases Transforming Growth Factor-beta (TGF-beta) signaling in mammary carcinoma cells and induces an epithelial to mesenchymal transition (EMT) that is in part dependent on its ability to increase TGF-beta signaling. TGF-beta signaling and EMT have been implicated in metastatic dissemination of carcinoma. Using spontaneous and experimental metastasis mouse models, we demonstrate that Six1 overexpression promotes breast cancer metastasis. In addition, we show that, like its induction of EMT, Six1-induced experimental metastasis is dependent on its ability to activate TGF-beta signaling. Importantly, in human breast cancers Six1 significantly correlates with nuclear Smad3, and thus increased TGF-beta signaling. Further, breast cancer patients whose tumors overexpress Six1 have a shortened time to relapse and metastasis, and an overall decrease in survival. Finally, we show that the effects of Six1 on tumor progression likely extend beyond breast cancer, since its overexpression correlates with adverse outcomes in numerous other cancers, including brain, cervical, prostate, colon, kidney, and liver, amongst others. Our findings argue that Six1, acting through TGF-beta signaling and EMT, is a powerful and global promoter of cancer metastasis.
Project description:Transforming growth factor-β (TGF-β) comprises a key component in the tumor microenvironment. It is reported that TGF-β can be pro-tumorigenic or anti-tumorigenic depending on various contexts. Some of the triple negative breast cancers highly express TGF-β, but pro-tumorigenic function of TGF-β in triple negative breast cancer cells is not fully known. Therefore, we analyzed genome-wide gene expression changes after stimulation with TGF-β in a triple negative breast cancer cell line, Hs578T cells.
Project description:RATIONALE: Measuring levels of transforming growth factor-beta (TGF-beta) in the blood of patients with epithelial cancers (head and neck, lung, breast, colorectal, and prostate) may help doctors predict how patients will respond to treatment with radiation therapy.
PURPOSE: This research study is measuring levels of TGF-beta in patients with epithelial cancers who are undergoing radiation therapy.