Hydrogen Peroxide Induces Cell Cycle Arrest in Cardiomyoblast H9c2 Cells, Which Is Related to Hypertrophy

Cell cycle arrest is associated with differentiation, senescence and apoptosis. We investigated alterations in the cell cycle during the development of hypertrophy induced by hydrogen peroxide (H2O2) in the H9c2 clonal myoblastic cell line. H2O2 induced hypertrophy in H9c2 cells that was indicated by an increase in atrial natriuretic peptide (ANP) gene expression, a marker of cardiomyocyte hypertrophy, and a larger cell size. On induction of hypertrophy by H2O2 in H9c2 cells, cell proliferation was arrested, indicated by the number of cells remaining constant during a 72-h incubation period. The cell cycle was arrested at the Cl and G2/M phases with an increase in p21 expression, a negative cell cycle regulator. Cell cycle arrest and increase in p21 expression were significantly inhibited by 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra (acetoxymethyl) ester (BAPTA-AM), an intracellular calcium chelator. Although ANP gene expression was induced significantly, H2O2 failed to induce hypertrophy in the presence of BAPTA-AM, and the cell cycle progressed. We concluded that H2O2 induced cell cycle arrest in H9c2 cells, which was related to cellular hypertrophy.