Bcl-2 protein is one of the major apoptosis regulators. The study examines the effect of Bcl-2 protein on the chemosensitivity of a human hepatocellular carcinoma cell line, QGY-7703. Western blot analysis showed that Bcl-2 and Bax proteins were expressed in QGY-7703 cells. Characteristic features of Taxol- and doxorubicin-induced apoptosis were evidenced by the Annexin-V binding assay, TUNEL and DAPI staining. At constant Bax protein levels, stable sense and antisense gene-transfected QGY-7703 cells showed that constitutive expression of Bcl-2 could render the cells more resistant to Taxol and doxorubicin. Contrarily, decreased Bcl-2 levels caused the cells to be more sensitive to the drugs. As Bcl-2 levels are directly proportional to the resistance of QGY-7703 cells to Taxol and doxorubicin, manipulation of Bcl-2 could be performed to enhance the sensitivity of liver cancer to chemotherapeutic agents.
Copyright 1999 S. Karger AG, Basel