Effects of Connexin43 Overexpression on U251 Cell Growth, Migration, and Apoptosis

BACKGROUND Glioblastoma multiforme (GBM) is a highly aggressive malignant brain tumor with a high incidence in adults. Connexin43 (Cx43) has general roles in tumorigenesis and is expressed in U251 glioma cells. Accordingly, the effects of Cx43 on the growth, migration, and apoptosis and the underlying mechanisms mediating Cx43-dependent migration and apoptosis were examined in U251 cells. MATERIAL AND METHODS A Cx43-overexpressing U251 cell line was generated to analyze the effects of Cx43 overexpression on cell growth, wound healing, and apoptosis-related protein expression after treatment with temozolomide. RESULTS The growth rate of U251 cells overexpressing Cx43 was significantly lower than that of parental wild-type cells, and cell morphology was considerably altered. The expression level of Bcl-2 was higher and the expression levels of Bax and caspase-3 were lower in cells overexpressing Cx43 than in wild-type cells. Additionally, the Bax/Bcl-2 ratio decreased. CONCLUSIONS Cx43 inhibited the growth of U251 cells, promoted morphological changes and migration, and inhibited apoptosis via a mitochondria-associated pathway.