PTPN11/SHP2 negatively regulates growth in breast epithelial cells: implications on tumorigenesis

2020 
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.
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    37
    References
    0
    Citations
    NaN
    KQI
    []