Leptin promotes expression of EMT-related transcription factors and invasion in a Src and FAK-dependent pathway in MCF10A mammary epithelial cells

Abstract

Leptin is one of the main adipokines secreted in breast tissue, and has been associated with epithelial-mesenchymal transition (EMT) and tumor progression in breast cancer. Leptin promotes EMT, cell migration and invasion in epithelial breast cells, leading to tumor progression. However, the molecular mechanism that underlies these events is not fully understood; however, the activation of different signaling pathways appears to be essential. In this sense, the effect of leptin on the activation of kinases like Src and FAK, which regulate signaling pathways that activate the EMT program, has not been completely described. Therefore, we investigated the involvement of these kinases using an in vitro model for leptin-induced EMT process in the non-tumorigenic MCF10A cell line. To this end, MCF10A cells were stimulated with leptin, and Src and FAK activation was assessed. Specific events occurring during EMT were also evaluated in the presence or absence of the kinases's chemical inhibitors PP2 and PF-573228. For instance, we tested the expression and subcellular localization of the EMT--catenin, by western blot and immunofluorescence. We also evaluated the secretion and activation of matrix metalloproteases (MMP-2 and MMP-9) by gelatin zymography. Invasiveness properties of leptin-stimulated cells were determined by invadopodia formation assays, and by the transwell chamber method. Our results showed that leptin promotes EMT through Src and FAK activation, which leads to the secretion and activation of MMP-2 and MMP-9, invadopodia formation and cell invasion in MCF10A cells. In conclusion, our data suggest that -catenin, the secretion of MMP-2, MMP-9, the invadopodia formation and invasion in MCF10A cells in a Src and FAK-dependent manner.

Loss of exosomal miR-146a-5p from cancer-associated fibroblasts after androgen deprivation therapy contributes to prostate cancer metastasis

“…Gelatin zymography was performed as previously described [ 26 ]; however, we made some modifications. Briefly, LNcaP and DU145 cells were incubated with CAFs-derived exosomes or/and transfected with miRNA mimics, then cultured in serum-free medium.…”

Src Family Kinases as Therapeutic Targets in Advanced Solid Tumors: What We Have Learned So Far

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MET transcriptional regulator/serine peptidase inhibitor kunitz type 1 panel operating through HGF/c‐MET axis as a prognostic signature in pan‐cancer

“…Transcription factors (TFs) are key proteins that regulate transcription rate of mRNAs of specific genes by binding to the promoter sequences with a unique structure 1,2 . Previous studies have revealed that dysregulation of tumor‐associated TFs mediated several malignant biological processes, including uncontrolled cell proliferation, apoptosis, metastasis, and invasion by affecting the proper expression of downstream signaling molecules 3‐5 . Therefore, the expression levels of TFs and their regulatory products (e.g., mRNAs, proteins, miRNAs, and lncRNAs) have been investigated to establish strategies for cancer diagnosis, prognosis, and evaluation of therapeutic responses 6‐8 .…”