Overexpression of the 32-kilodalton dopamine and cyclic adenosine 3',5'-monophosphate-regulated phosphoprotein in common adenocarcinomas.

Background: The 32-kilodalton dopamine and cyclic adenosine 3',5'-monophosphate-regulated phosphoprotein (DARPP-32) is the only known protein that can act as a protein phosphatase-1 inhibitor or a protein kinase inhibitor. It is known as a neurogenic protein that plays a major role in dopamine regulation in the central nervous system. Recently, DARPP-32 and a truncated isoform, t-DARPP, have been cloned in gastric carcinoma.

Gastric cancers overexpress DARPP-32 and a novel isoform, t-DARPP.

Gastric carcinoma is the second most common cause of cancer-related death worldwide. Recently, we have demonstrated that expressed sequence tag AA552509 was frequently amplified and the most consistently overexpressed target at 17q in gastric cancers. Herein, we report that DARPP-32 (dopamine and cAMP-regulated phosphoprotein of M(r) 32,000) is the target gene for overexpression of expressed sequence tag AA552509.