Abstract: Abstract: Objective To investigate the targeted silencing of neurotrophic factor tyrosine kinase receptor B (TrkB) gene in SW620 colon cancer cell line on the apoptotic level of anoikis. Methods TrkB-shRNA lentivirus interference vector was constructed to infect SW620 cells. Real-time PCR and Western blot assay were used to detect the expression levels of TrkB gene at levels of RNA and protein respectively. ELISA assay was performed to investigate the apoptotic level of anoikis after down-regulation of TrkB gene expression in adhering and suspension cells. Results TrkB-shRNA lentivirus interference vector was successfully constructed to obtain SW620-iTrkB stable infected cell line. Compared with the SW620-iLuc control group, the mRNA and protein relative expression levels of TrkB gene were significantly decreased in SW620-iTrkB cells (P＜0.05). It was found that different growth states and different transfection plasmid transfections showed effects on the apoptotic levels of anoikis in SW620-iTrkB cells, and there were interaction effects between them (P＜ 0.05). Compared with the adherent cells, the apoptosis rates were significantly increased in the suspension cells of SW620- iLuc group and SW620-iTrkB group (P＜0.05). In the suspension group, the apoptosis rate was significantly higher in SW620-iTrkB group than that of SW620-iLuc group (P＜0.05). Conclusion Lentiviral vector-mediated TrkB-shRNA can produce specific gene silencing effect in colon cancer SW620 cells, which significantly increases the apoptotic level of anoikis.

Key words: receptor protein-tyrosine kinases, anoikis, gene silencing, neoplasm metastasis, shRNA