Oncostatin M-induced ABCC2 suppression sensitizes hepatocellular carcinoma cells to chemotherapeutics.

Oncostatin M (OncM/OSM), a member of the interleukin-6 family, was first characterized for inhibition of tumour cell proliferation. Physiologically, this cytokine participates in haematopoietic processes and is involved in normal functioning of systems and organs. However, Oncostatin M exhibits also modulatory properties on activity of cytochrome P-450 and ABC superfamily (ATP-binding cassette) proteins, which are considered to be cornerstones of multidrug resistance (MDR) phenotype. The aim of this study was to determine the role and effect of OSM on the expression and activity of ABCC2 (cMOAT), an ABC transporter, in a hepatocellular carcinoma line (Hep G2) as an model. Our results suggest that this cytokine reduces expression of ABCC2 which may have potent consequences for the biliary transport.