The molecular mechanism that down-regulation of VEGF gene transcription inhibits nasopharyngeal carcinoma cell proliferation

Abstract

Objective To investigate down-regulation of vascular endothelial growth factor (VEGF) gene at mRNA level on effects of nasopharyngeal carcinoma (NPC) cell proliferation and analyze the key molecule expressions of extracellular-signal regulated protein kinase/mitogen-activated protein kinase (Erk/MAPK) pathway to explore its molecular mechanism. Methods Highest-efficiency VEGF-siRNA plasmid was successfully constructed and screened, confirmed by sequencing, and then transfected to CNE2 cell line. Interference efficiency was quantitatively evaluated by a fluorescence quantitation polymerase chain reaction assay. Expressions of VEGF, cell cycle regulator cyclin D1, and key molecules in Erk/MAPK pathway were analyzed with Western blot. Cell proliferation was tested by cell counting kit-8 (CCK-8) kit. Clone formation rate was checked with plate clone formation assay. Alteration of cell cycle was measured with flow cytometry. Stable cell clones were screened by G418. Results VEGF expression in NPC cells transfected with specific siRNA were significantly down-regulated at the levels of mRNA or protein, and cell proliferations were inhibited in a time-dependent manner, with significant decreases of colony-forming, cyclinD1, and p-Erk, and with cell cycle arrested at G1 phase. Conclusions Intervencing VEGF gene transcription inhibited NPC cell proliferation through Erk/MAPK signaling pathway, and suggesting that VEGF should be a novel therapeutic target for NPC. Key words: Vascular endothelial growth factors/PD; RNA, small interfering; Nasopharyngeal neoplasms/DT; Cell proliferation; Neoplasm metastasis