lucifer-yellow and Glioblastoma

Stable re-expression of connexin 43 (cx43) in human glioblastoma suppresses transformation and tumorigenicity. The present study was designed to examine the role of cx43 in chemotherapy-induced apoptosis. Expression of cx43 in human glioblastoma cells significantly increased sensitivity to several common chemotherapeutic agents, including etoposide, paclitaxel (Taxol) and doxorubicin, compared with control-transfected cells. The increased sensitivity to chemotherapeutic agents resulted from apoptosis as evidenced by Hoechst dye staining, TUNEL assay and annexin V assay. These cx43-mediated effects were coupled with decreased expression of the specific apoptosis inhibitor bcl-2. Over-expression of bcl-2 in cx43-transfected cells partially confers the resistance to apoptosis induced by etoposide, suggesting that the cx43-mediated apoptosis to chemotherapeutic agents is regulated in part through the down-regulation of bcl-2 expression. Furthermore, the cx43-mediated apoptosis in response to chemotherapeutic drugs may not be linked to increased gap junctional communication in cx43-transfected cells. Our results demonstrate a new role of cx43 in the mediation of apoptosis during chemotherapy.

Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Cell Survival; Connexin 43; Drug Interactions; Etoposide; Flow Cytometry; Fluorescent Dyes; G2 Phase; Gap Junctions; Gene Expression Regulation; Glioblastoma; Humans; In Situ Nick-End Labeling; Isoquinolines; Proto-Oncogene Proteins c-bcl-2; Transfection; Tumor Cells, Cultured