Abstract

AbstractOverexpression of CKS1B, a gene mapping within a minimally amplified region between 153 to 154 Mb of chromosome 1q21, is linked to a poor prognosis in multiple myeloma (MM). CKS1B binds to and activates cyclin-dependent kinases and also interacts with SKP2 to promote the ubiquitination and proteasomal degradation of p27Kip1. Overexpression of CKS1B or SKP2 contributes to increased p27Kip1 turnover, cell proliferation, and a poor prognosis in many tumor types. Using 4 MM cell lines harboring MAF-, FGFR3/MMSET-, or CCND1-activating translocations, we show that lentiviral delivery of shRNA directed against CKS1B resulted in ablation of CKS1B mRNA and protein with concomitant stabilization of p27Kip1, cell cycle arrest, and apoptosis. Although shRNA-mediated knockdown of SKP2 and forced expression of a nondegradable form of p27Kip1 (p27T187A) led to cell cycle arrest, apoptosis was modest. Of importance, while knockdown of SKP2 or overexpression of p27T187A induced cell cycle arrest in KMS28PE, an MM cell line with biallelic deletion of CDKN1B/p27Kip1, CKS1B ablation induced strong apoptosis. These data suggest that CKS1B influences myeloma cell growth and survival through SKP2- and p27Kip1-dependent and -independent mechanisms and that therapeutic strategies aimed at abolishing CKS1B function may hold promise for the treatment of high-risk disease for which effective therapies are currently lacking.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.