Search

Chemoresistance is a primary cause of breast cancer treatment failure, and protein-protein interactions significantly contribute to chemoresistance during different stages of breast cancer progression. In pursuit of novel biomarkers and relevant protein-protein interactions occurring during the emergence of breast cancer chemoresistance, we used a computational predictive biological (CPB) approach. CPB identified associations of adhesion molecules with proteins connected with different breast cancer proteins associated with chemoresistance. This approach identified an association of Integrin β1 (ITGB1) with chemoresistance and breast cancer stem cell markers. ITGB1 activated the Focal Adhesion Kinase (FAK) pathway promoting invasion, migration, and chemoresistance in breast cancer by upregulating Erk phosphorylation. FAK also activated Wnt/Sox2 signaling, which enhanced self-renewal in breast cancer. Activation of the FAK pathway by ITGB1 represents a novel mechanism linked to breast cancer chemoresistance, which may lead to novel therapies capable of blocking breast cancer progression by intervening in ITGB1-regulated signaling pathways. [Display omitted] • Developed a novel Computational-Predictive-Biological (CPB) strategy to predict different types of biomarkers in cancers. • CBP identified that ITGB1 is associated with chemoresistance, and cancer stem cell associated proteins in breast cancer. • ITGB1 regulated chemoresistance via activation of FAK pathway which regulates survival pathways, invasion, migration. • ITGB1 also regulated activated Wnt/Sox2 signaling through FAK, which enhanced self-renewal in breast cancer. • Thus, CBP established a unified pathway to regulate chemoresistance in breast cancer and ITGB1 as a potential biomarker. [ABSTRACT FROM AUTHOR]

The Transforming growth factor-β1 (TGF- β1) in the tumor microenvironment (TME) is the major cytokine that acts as a mediator of tumor-stroma crosstalk, which in fact has a dual role in either promoting or suppressing tumor development. The cancer-associated fibroblasts (CAFs) are the major cell types in the TME, and the interaction with most of the epithelial cancers is the prime reason for cancer survival. However, the molecular mechanisms, associated with the TGF- β1 induced tumor promotion through tumor-CAF crosstalk are not well understood. In the Reverse Warburg effect, CAFs feed the adjacent cancer cells by lactate produced during the aerobic glycolysis. We hypothesized that the monocarboxylate transporter, MCT4 which is implicated in lactate efflux from the CAFs, must be overexpressed in the CAFs. Contextually, to explore the role of TGF- β1 in the hypoxia-induced autophagy in CAFs, we treated CoCl 2 and external TGF- β1 to the human dermal fibroblasts and L929 murine fibroblasts. We demonstrated that hypoxia accelerated the TGF- β1 signaling and subsequent transformation of normal fibroblasts to CAFs. Moreover, we elucidated that synergistic induction of autophagy by hypoxia and TGF- β1 upregulate the aerobic glycolysis and MCT4 expression in CAFs. Furthermore, we showed a positive correlation between glucose consumption and MCT4 expression in the CAFs. Autophagy was also found to be involved in the EMT in hypoxic CAFs. Collectively, these findings reveal the unappreciated role of autophagy in TME, which enhances the CAF transformation and that promotes tumor migration and metastasis via the reverse Warburg effect. [Display omitted] • The crosstalk between the tumor and CAFs via TGF-β1 promotes tumor progression. • TGF-β1 from the tumors induces the transformation of normal fibroblast to CAFs. • Synergistically, TGF-β1, and hypoxia induce autophagy in the CAFs. • CAFs metabolically support tumor growth via lactate production and MCT4 upregulation. [ABSTRACT FROM AUTHOR]