Definition

An orally bioavailable small molecule inhibitor of phosphorylated-p68 RNA helicase (P-p68), with potential anti-proliferative and antineoplastic activity. Upon oral administration, P-p68 inhibitor RX-5902 may both inhibit the activity of the anti-apoptotic B-cell lymphoma 2 (Bcl-2) protein and facilitate the induction of cyclin-dependent kinase inhibitor 1 (p21). This may prevent G2/M cell cycle progression and lead to growth inhibition in tumor cells. P-p68 is overexpressed in various types of solid tumors but absent in normal tissues, and plays a role in tumor progression and metastasis. p21 is a potent cyclin-dependent kinase inhibitor which regulates cell cycle progression and mediates both growth arrest and cellular senescence.