In the search to identify kinases required for human cancer cell growth, we found CDK11 (PITSLRE) by a comprehensive human kinome-wide shRNA screen to be critical for human cancer cell growth and proliferation. We observed that the expression level of CDK11 was elevated in a variety of human cancer cells and tumor tissues. Furthermore, knock-down of CDK11 either by lentiviral shRNA or by synthetic siRNA inhibits cell growth and induces apoptosis in human cancer cells. In these cells, suppression of CDK11 reduces the expression of several antiapoptotic genes essential for tumor cell survival and proliferation including MCL-1, BcL-XL and survivin. We showed by immunohistochemical analysis that osteosarcoma and ovarian cancer patients with high CDK11 tumor expression levels were associated with significantly shorter survival than patients with lower expression levels of CDK11 expression. Systemic administration of In Vivo Ready siRNA of CDK11 reduced tumor growth in an osteosarcoma s.c. xenograft model. Taken together, these observations suggest that CDK11 signaling is essential in human cancer cell growth and survival. CDK11 may serve as a promising therapeutic target in the treatment of human cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 859. doi:1538-7445.AM2012-859