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Padilla Lab publishes two recent papers

Date Posted: Thursday, October 10, 2019


Teresita Padilla-Benavides, PhD, recently published research papers in Cells and bioRxiv. Read the abstracts below and follow the links to the full text:

Leptin Promotes Expression of EMT-Related Transcription Factors and Invasion in a Src and FAK-Dependent Pathway in MCF10A Mammary Epithelial Cells

Abstract: 
Leptin promotes expression...Leptin is one of the main adipokines secreted in breast tissue. Leptin promotes epithelial–mesenchymal transition (EMT), cell migration and invasion in epithelial breast cells, leading to tumor progression. Although, the molecular mechanisms that underlie these events are not fully understood, the activation of different signaling pathways appears to be essential. In this sense, the effects of leptin on the activation of kinases like Src and FAK, which regulate signaling pathways that activate the EMT program, are not 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’ chemical inhibitors PP2 and PF-573228. For instance, we tested the expression and subcellular localization of the EMT-related transcription factors Twist and β-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 leptin promotes an increase in the expression levels of Twist and β-catenin, the secretion of MMP-2, MMP-9, the invadopodia formation and invasion in MCF10A cells in a Src and FAK-dependent manner.

Leptin induces cell migration and invasion in a FAK-Src- dependent manner in breast cancer cells

Abstract: 
Leptin induces cell migration...Breast cancer is the most common invasive neoplasia, and the second leading cause of death associated with cancer in women worldwide. Mammary tumorigenesis is severely linked to obesity, the potential connection is leptin. Leptin is a hormone secreted by adipocytes, which contributes to the progression of breast cancer. Cell migration, metalloproteases secretion, and invasion are cellular processes associated with various stages of metastasis. These processes are regulated by the kinases FAK and Src. In this study, we utilized the breast cancer cell lines MCF7 and MDA-MB-231 to determine the effect of leptin on FAK and Src kinases activation, cell migration, metalloproteases secretion, and invasion. By Western blot we found that leptin activates FAK and Src, and induces the localization of FAK to the focal adhesions. Specific inhibitors of FAK and Src showed that the effect exerted by leptin in cell migration, and invasion in breast cancer cells is dependent on these kinases. Moreover, by gelatin zymmography we established that leptin promotes the secretion of the extracellular matrix remodelers, MMP-2 and MMP-9, in a FAK and Src dependent manner. Our findings strongly suggest that leptin promotes the development of a more aggressive invasive phenotype in mammary cancer cells.

 

For more about the Padilla Lab, please visit www.umassmed.edu/padillalab

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