OBJECTIVEThe purpose of this study was to investigate the effect of an angiogenesis inhibitor (TNP-470) on the ultra micro-structural morphological changes of GNM cell line, which was derived from human oral squamous cell carcinomas in vitro.

METHODSThe GNM cells were cultured and, the effect of TNP-470 on ultra micro-structural morphological changes of GNM cells was observed under the inverted microscope, the scanning electron microscope (SEM) and the transmission electron microscope (TEM).

RESULTSNumerous round cells, shrinkage of cellular membrane and dead cells were observed 48 hours after 2 micrograms/ml of TNP-470 was added into the GNM cellular suspension. After 72 hours, GNM cells became shortened and, the number of microvilli of the cellular surface was observed under the SEM and TEM. A large number of GNM cells turned into necrosis, accompanying with the destruction of mitochondria and endoplasmic reticula.

CONCLUSIONTNP-470 has a strong tumor cytotoxic effect on GNM cells, which may be due to its destructibility on mitochondria and endoplasmic reticula of GNM cells. TNP-470 can alter the surface structure of GNM cell membrane, which suggests that TNP-470 may interrupt the metastasis of GNM cells.