Objective: To employ RNA interference technology to silence transforming growth factor-β1 (TGF-β1) gene to examine the gene silencing effects of RNAi on the expression of vascular endothelial growth factor (VEGF) in human bladder cancer cell lines (EJ).
Methods: The TGF-β1 gene-specific siRNA expression vector was constructed. And the most efficiently suppressed target sequences were screened through reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). The samples were divided into 3 groups of EJ, control (TGF-β1) and recombinant plasmid (TGF-β1 siRNA expression vector). And the expression level of VEGF protein was detected by Western blot.
Results: TGF-β1 gene-specific siRNA expression vector was constructed successfully. TGF-β1 relative mRNA expression was 0.92 ± 0.19 and the protein expression level (50 ± 6) pg/ml. The protein expression level of EJ group after transfection was (0.86 ± 0.18) pg/ml, control group (1.15 ± 0.29) pg/ml and recombinant plasmid group (0.45 ± 0.16) pg/ml(both P < 0.05).
Conclusions: An inhibition of TGF-β1 gene down-regulates the expression of VEGF. And TGF-β1 may regulate angiogenesis of bladder tumor through an induction of VEGF gene expression.