ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of Platycarya strobilacea Sieb. et Zucc (PSZ) extract on methuosis of human nasopharyngeal carcinoma CNE1 and CNE2 cells and explore the underlying mechanism.</p><p><b>METHODS</b>CNE1 and CNE2 cells were treated with 1 mg/mL PSZ extract and the expressions of Rac1 mRNA and Rac1 protein were detected using RT-qPCR and Western blotting, respectively. Results CNE1 and CNE2 cells showed obvious morphological changes typical of methuosis following treatment with PSZ extract characterized by cell merging, accumulation of large cytoplasmic vacuoles, and membrane rupture without obvious changes in the nuclei. PSZ treatment resulted in up-regulated Rac1 mRNA and Rac1 protein expressions in the cells. Application of EHT 1864 obviously blocked the effect of PSZ extract in inducing methuosis in CNE1 and CNE2 cells.</p><p><b>CONCLUSION</b>PSZ extract can induce methuosis in CNE1 and CNE2 cells by inducing the overexpression of Rac1.</p>