Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.30.228445v1?rss=1 Authors: Chakladar, M., Nair, M., Prabhu, J., Sridhar, T., Kelkar, D., Kulkarni, M., SHASHIDHARA, L. Abstract: PTPN11/SHP2, a non-receptor protein tyrosine phosphatase is a prominent target of the receptor tyrosine kinase that participates in positive feedback signalling of the human epidermal growth factor receptors and helps in growth and migration. PTPN11/SHP2 is widely believed to be an oncoprotein, although its possible tumor-suppressor role is also reported. Our analysis of breast cancer metadata shows, PTPN11/SHP2 copy number loss in luminal A subtype is correlated to poor disease-specific survival and late-stage cancer at diagnosis. Analysis of the level 4 Reverse Phase Protein Array (RPPA) data available on the TCGA database resulted in positive correlations between the lower expression levels of constitutively active variant, the phospho-SHP2-Y542, of PTPN11/SHP2 and larger tumor size and lymph node positivity. We experimentally examined possible negative regulation of growth by PTPN11/SHP2 using MCF10A, a normal breast epithelial cell line. Knock-down of PTPN11/SHP2 resulted in increased cell migration, cell shape changes to mesenchymal morphology, and increased survival in cells treated with epirubicin, a DNA-damaging drug. However, it did not alter the rate of cell proliferation. It is possible that PTPN11/SHP2 might function as a tumor suppressor by potentiating proliferating cells with increased cell migration and resistance to apoptosis. Copy rights belong to original authors. Visit the link for more info