Systematic kinome shRNA screening identifies CDK11 (PITSLRE) kinase expression is critical for osteosarcoma cell growth and proliferation.
OBJECTIVE
Identification of new targeted therapies is critical to improving the survival rate of patients with osteosarcoma. The goal of this study is to identify kinase based potential therapeutic target in osteosarcomas.


METHODS
We used a lentiviral-based shRNA kinase library to screen for kinases which play a role in osteosarcoma cell survival. The cell proliferation assay was used to evaluate cell growth and survival. siRNA assays were applied to confirm the observed phenotypic changes resulting from the loss of kinase gene expression. CDK11 (PITSLRE) was identified as essential for the survival of osteosarcoma cells, and its expression was confirmed by Western blot analysis and immunohistochemistry. Overall patient survival was correlated with the CDK11 expression and its prognosis. The role of CDK11 expression in sustaining osteosarcoma growth was further evaluated in an osteosarcoma xenograft model in vivo.


RESULTS
Osteosarcoma cells display high levels of CDK11 expression. CDK11 expression knocked down by either lentiviral shRNA or siRNA inhibit cell growth and induce apoptosis in osteosarcoma cells. Immunohistochemical analysis showed that patients with osteosarcoma with high CDK11 tumor expression levels were associated with significantly shorter survival than patients with osteosarcoma with low level of tumor CDK11 expression. Systemic in vivo administration of in vivo ready siRNA of CDK11 reduced the tumor growth in an osteosarcoma subcutaneous xenograft model.


CONCLUSIONS
We show that CDK11 signaling is essential in osteosarcoma cell growth and survival, further elucidating the regulatory mechanisms controlling the expression of CDK11 and ultimately develop a CDK11 inhibitor that may provide therapeutic benefit against osteosarcoma.
Center for Sarcoma and Connective Tissue Oncology and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA. zduan@partners.org
Zhenfeng
Z
Duan
Jianming
J
Zhang
Edwin
E
Choy
David
D
Harmon
Xianzhe
X
Liu
Petur
P
Nielsen
Henry
H
Mankin
Nathanael S
NS
Gray
Francis J
FJ
Hornicek
D000293:Adolescent; D000328:Adult; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D051379:Mice; D008875:Middle Aged; D012516:Osteosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics; D014183:Transplantation, Heterologous
D034741:RNA, Small Interfering; C447612:CDK11a protein, human; D018844:Cyclin-Dependent Kinases