Experimental oncology

Kinase suppressor of Ras 2 is involved in regulation of cell proliferation and is up-regulated in human invasive ductal carcinomas of breast.

PMID 21403620


To study the expression of Kinase Suppressor of Ras 2 (KSR2) in human breast tumors and its effect on proliferation of breast epithelial cells. We reported previously that KSR2 was up-regulated in immortalized human breast epithelial cells. Proteomics technologies, systems biology tool for a KSR2 network analysis, immunoblotting, siRNA technology, overexpression of KSR2, cell proliferation assays and immunohistochemistry of tissue microarray of human breast tumors and normal breast tissue were used. In conditionally immortalized primary epithelial cells KSR2 expression was shown to be up-regulated. The involvement of KSR2 in regulation of cell proliferation was predicted by a KSR2-centered network analysis. We observed that KSR2 down-regulation with specific siRNA inhibited cell proliferation. By immunohistochemistry of tissue microarray it was demonstrated that KSR2 expression was enhanced in human invasive breast carcinomas. Our findings propose KSR2 as a new marker of immortalization, which has an impact on cell proliferation.