CDK4/6 Inhibitor PD 0332991 Sensitizes Acute Myeloid Leukemia to Cytarabine-Mediated Cytotoxicity. Academic Article uri icon

Overview

abstract

  • Cyclin-dependent kinase (CDK)4 and CDK6 are frequently overexpressed or hyperactivated in human cancers. Targeting CDK4/CDK6 in combination with cytotoxic killing therefore represents a rational approach to cancer therapy. By selective inhibition of CDK4/CDK6 with PD 0332991, which leads to early G1 arrest and synchronous S-phase entry upon release of the G1 block, we have developed a novel strategy to prime acute myeloid leukemia (AML) cells for cytotoxic killing by cytarabine (Ara-C). This sensitization is achieved in part through enrichment of S-phase cells, which maximizes the AML populations for Ara-C incorporation into replicating DNA to elicit DNA damage. Moreover, PD 0332991 triggered apoptosis of AML cells through inhibition of the homeobox (HOX)A9 oncogene expression, reducing the transcription of its target PIM1. Reduced PIM1 synthesis attenuates PIM1-mediated phosphorylation of the proapoptotic BAD and activates BAD-dependent apoptosis. In vivo, timely inhibition of CDK4/CDK6 by PD 0332991 and release profoundly suppresses tumor growth in response to reduced doses of Ara-C in a xenograft AML model. Collectively, these data suggest selective and reversible inhibition of CDK4/CDK6 as an effective means to enhance Ara-C killing of AML cells at reduced doses, which has implications for the treatment of elderly AML patients who are unable to tolerate high-dose Ara-C therapy.

publication date

  • March 5, 2015

Research

keywords

  • Antineoplastic Agents
  • Cyclin-Dependent Kinase 4
  • Cyclin-Dependent Kinase 6
  • Leukemia, Myeloid, Acute
  • Piperazines
  • Protein Kinase Inhibitors
  • Pyridines

Identity

PubMed Central ID

  • PMC4417369

Scopus Document Identifier

  • 84937925218

Digital Object Identifier (DOI)

  • 10.1158/0008-5472.CAN-14-2486

PubMed ID

  • 25744718

Additional Document Info

volume

  • 75

issue

  • 9