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Dependency of Cholangiocarcinoma on Cyclin D-Dependent Kinase Activity

Cholangiocarcinoma (CCA) is a bile duct cancer with a very poor prognosis. Currently, there is no effective pharmacological treatment available for it. We showed that CCA ubiquitously relies on CDK4/6 activity to proliferate. Primary CCA tissues express high levels of cyclin D1 and the specific marker of CDK4/6 activity, phospho-RB Ser780. Treatment of a 15-CCA cell line collection by pharmacological CDK4/6 inhibitors leads to reduced numbers of cells in the S-phase and senescence in most of the CCA cell lines. We found that expression of pRB is required for the activity of the CDK4/6 inhibitor and that loss of pRB conferred the CDK4/6 inhibitor-drug resistance. We also identified that the sensitivity of CCA to CDK4/6 inhibition is associated with the activated KRAS signature. The effectiveness of CDK4/6 inhibition for CCA was confirmed in the 3D spheroid, xenograft, and patient-derived xenograft models. Lastly, we identified a list of genes whose expressions can be used to predict the response to the CDK4/6 inhibitor. CONCLUSION: We uncovered a ubiquitous dependency of CCA on CDK4/6 activity, and the universal response to CDK4/6 inhibition. We propose that the CDK4/6-pRB pathway is a suitable therapeutic target for CCA treatment. This article is protected by copyright. All rights reserved.

Related Products

Cat.No. Product Name Information Publications Customer Product Validation
S1116 Palbociclib (PD-0332991) HCl Palbociclib (PD-0332991) HCl is a highly selective inhibitor of CDK4/6 with IC50 of 11 nM/16 nM in cell-free assays, respectively. It shows no activity against CDK1/2/5, EGFR, FGFR, PDGFR, InsR, etc. Phase 3. (335) (11)

Related Targets

CDK