All trans retinoic acid and cancer.

All-trans retinoic acid (ATRA) is an active metabolite of vitamin A under the family retinoid. Retinoids, through their cognate nuclear receptors, exert potent effects on cell growth, differentiation and apoptosis, and have significant promise for cancer therapy and chemoprevention. Differentiation therapy with ATRA has marked a major advance and become the first choice drug in the treatment of acute promyelocytic leukemia (APL). Conversions of 13-cis-retinoic acid and 9-cis-retinoic acid to all-trans-retinoic acid is very rapid. Currently, two distinct families of retinoid responsive nuclear receptors have been identified and characterized: retinoic acid receptors (RARs) and retinoid receptors (RXRs), each of which include three isoforms, α,β,and γ. ATRA is being increasingly included in anti-tumour therapeutical schemes for the treatment of various tumoral diseases such as Kaposi's sarcoma, head and neck squamous cell carcinoma, ovarian carcinoma, bladder cancer, neuroblastoma and has shown antiangiogenic effects in several systems, inhibiting proliferation in vascular smooth muscle cells (VSMCs) and anti-inflammatory in rheumatoid arthritis. This review helps to understand in details about the ATRA and its role on cancer and it is predicted that modulating the activity of ATRA will soon provide novel prevention and treatment approaches for the cancer patients.