The
quinolinone derivative,
vesnarinone, is a novel inotropic agent used in the treatment of
heart failure. It has also been found that
vesnarinone has a potential anti-
cancer activity. To evaluate the anti-
cancer activity of
vesnarinone in combination with irradiation, we investigated the
cytostatic and cytotoxic effects on human
lung cancer cell lines (PC-9 and Lu 134A) using MTT assay and isobologram analysis. We also analyzed the nuclear fragmentation of
tumor cells by flow cytometric analysis. Our study demonstrated that combination of
vesnarinone with irradiation had an additive inhibitory effect on both PC-9 and Lu 134A
tumor cell growth.
Vesnarinone could improve the sensitivity of
tumor cells to irradiation and thus the dose of irradiation could be reduced to half without decreased inhibitory effect. Significant increase of the
tumor cell nuclear fragmentation was observed with combination of
vesnarinone and irradiation. These results indicate that
vesnarinone not only directly inhibited
tumor cell growth, but also improved the sensitivity to irradiation. Combination of
vesnarinone with irradiation may be an efficacious protocol for
lung cancer treatment. The inhibitory effect was ascribed to inducing
tumor cell apoptosis.