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RNA interference remarkably suppresses bcl-2 gene expression in cancer cells in vitro and in vivo
Geng-Feng Fu1, Xue-Hong Lin, Qing-Wang Han
1Medical School and State Key Loboratory of Pharmaceutical Biotechnology, Nanjing University, China.
Abstract:
Bcl-2 is an anti-apoptotic protein. If the level of Bcl-2 protein can be reduced sufficiently in tumors using RNA interference (RNAi) to target the gene message, the apoptosis of tumor cells may be promoted. In this study, we synthesized 19 nucleotides (nts) small interference RNA (siRNA) constructs suppressing bcl-2 gene expression in human tumor cells (HeLaB2 and BGC-823 cell lines) in vitro. The bcl-2 gene expression levels were significantly reduced when these siRNA were transfected into experimental two tumor cells for 72 hours. The apoptosis process was also examined in the tumor cells. Here we synthesized siRNA from a DNA template under the control of the RNA polymerase III promoter in transfected tumor cells. Using this DNA vector-based approach, we found that the siRNA efficiently and specifically inhibited the synthesis of protein encoded by the bcl-2 gene in HeLaB2 and BGC-823 tumor cells. Tumor growth was inhibited by 66.5% with 2mg/kg pSilencer 3.1H1-bcl-2 in mouse liver tumor-bearing BALB/c mice. This approach may prove to be a valuable clinical technique for the analysis of specific gene functions and gene therapy of malignant tumors that utilize the bcl-2 gene via RNA interference.
Insights
Small interfering RNA (siRNA) targeting the anti-apoptotic Bcl-2 protein effectively suppressed gene expression in human tumor cells. This RNA interference approach significantly inhibited tumor growth in mice, offering potential for gene therapy.
Area of Science:
- Molecular Biology
- Cancer Research
- Gene Therapy
Background:
- Bcl-2 is an anti-apoptotic protein that promotes tumor cell survival.
- Reducing Bcl-2 levels via RNA interference (RNAi) could induce tumor cell apoptosis.
- Targeting Bcl-2 is a potential strategy for cancer treatment.
Purpose of the Study:
- To develop and evaluate small interfering RNA (siRNA) constructs for suppressing Bcl-2 gene expression.
- To assess the efficacy of siRNA in inhibiting tumor cell growth in vitro and in vivo.
- To explore the potential of DNA vector-based RNA interference for cancer gene therapy.
Main Methods:
- Synthesized 19-nucleotide siRNA constructs targeting the bcl-2 gene message.
- Transfected siRNA into human tumor cell lines (HeLaB2 and BGC-823) in vitro.
- Utilized a DNA vector-based approach with RNA polymerase III promoter for siRNA synthesis.
- Administered siRNA via a DNA vector (pSilencer 3.1H1-bcl-2) to tumor-bearing mice.
Main Results:
- Significantly reduced bcl-2 gene expression in HeLaB2 and BGC-823 cells within 72 hours.
- Demonstrated efficient and specific inhibition of Bcl-2 protein synthesis.
- Achieved a 66.5% inhibition of tumor growth in mouse liver tumor models at 2mg/kg.
- Observed promotion of apoptosis in treated tumor cells.
Conclusions:
- DNA vector-based RNA interference effectively suppresses Bcl-2 expression and inhibits tumor growth.
- This method shows promise as a clinical technique for gene function analysis.
- RNA interference targeting Bcl-2 represents a potential gene therapy strategy for malignant tumors.
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