Effects of roniciclib in preclinical models of anaplastic thyroid cancer.

Many human cancers have altered cyclin-dependent kinase activity. Inhibition of cyclin-dependent kinases may arrest cell cycle progression and represents an important strategy in the treatment of malignancies. We evaluated the therapeutic effects of roniciclib, a cyclin-dependent kinase inhibitor, as a treatment for anaplastic thyroid cancer. Roniciclib inhibited anaplastic thyroid cancer cell proliferation in a dose-dependent manner. Roniciclib activated caspase-3 activity and induced apoptosis. Cell cycle progression was arrested in G2/M phase. In vivo, the growth of anaplastic thyroid cancer xenograft tumors was retarded by roniciclib treatment without evidence of toxicity. These data provide a rationale for further clinical evaluation using roniciclib in the treatment of patients with anaplastic thyroid cancer.