CDK8 is a colorectal cancer oncogene that regulates beta-catenin activity by Firestein Ron, Bass Adam J, Kim So Young, Dunn Ian F, Silver Serena J, Guney Isil, Freed Ellen, Ligon Azra H, Vena Natalie, Ogino Shuji, Chheda Milan G, Tamayo Pablo, Finn Stephen, Shrestha Yashaswi, Boehm Jesse S, Jain Supriya, Bojarski Emeric, Mermel Craig, Barretina Jordi, Chan Jennifer A, Baselga Jose, Tabernero Josep, Root David E, Fuchs Charles S, Loda Massimo, Shivdasani Ramesh A, Meyerson Matthew, Hahn William C in Nature (2008). PubMed

Abstract

Aberrant activation of the canonical WNT/beta-catenin pathway occurs in almost all colorectal cancers and contributes to their growth, invasion and survival. Although dysregulated beta-catenin activity drives colon tumorigenesis, further genetic perturbations are required to elaborate full malignant transformation. To identify genes that both modulate beta-catenin activity and are essential for colon cancer cell proliferation, we conducted two loss-of-function screens in human colon cancer cells and compared genes identified in these screens with an analysis of copy number alterations in colon cancer specimens. One of these genes, CDK8, which encodes a member of the mediator complex, is located at 13q12.13, a region of recurrent copy number gain in a substantial fraction of colon cancers. Here we show that the suppression of CDK8 expression inhibits proliferation in colon cancer cells characterized by high levels of CDK8 and beta-catenin hyperactivity. CDK8 kinase activity was necessary for beta-catenin-driven transformation and for expression of several beta-catenin transcriptional targets. Together these observations suggest that therapeutic interventions targeting CDK8 may confer a clinical benefit in beta-catenin-driven malignancies.

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