Anticancer effects of a novel chroman analog in HeLa cells are associated with G2‑phase arrest and mitochondrial‑mediated apoptosis.

In the present study, the anticancer activity of 1‑[(3S,4R)‑2,2‑dimethyl‑3‑oxo‑4‑(2‑piperidonyl)chroman‑6‑yl]‑3‑phenylurea (S32) was investigated by testing its effect in vitro on the growth of HeLa cells. First, we showed that the IC50 value of S32 was ~70 µM by using WST‑8 assay, and that it significantly inhibited the proliferation and viability of HeLa cells in a dose‑dependent manner after 48 h. Morphological changes in apoptotic cells included cellular shrinkage and nuclear condensation. The results of [3H]‑thymidine incorporation and flow cytometric analysis indicated that S32 induced inhibition of DNA replication and G2‑phase cell cycle arrest. Moreover, S32 induced the levels of reactive oxygen species (ROS) and decreased the mitochondrial membrane potential (MMP) in a time‑dependent manner. Using Annexin V‑FITC/propidium iodide (PI) dual staining assay, we found that S32 noticeably increased early apoptosis in HeLa cells in a time‑dependent manner. The result of western blot analysis showed that the apoptotic induction was associated with an increase in Bax levels and a decrease in Bcl‑2 levels, which led to activation of caspase‑8, ‑9 and ‑3. Taken together, our findings demonstrated that S32 induces mitochondrial‑mediated apoptosis in HeLa cells and suggest that S32 has potential as an anticancer drug.