Related Experiment Videos
[Ectopic expression of cyclin G2 inhibits cell proliferation in HeLa cancer cell line]
Yu-lou Tian1, Fu-rong Liu, Jie Liu
1Department of Cell Biology, China Medical University, Shenyang 110001, P. R. China.
Background & Objective:
Cyclins are important proteins in cell cycle machinery, acting as positive regulators in cell proliferation. Cyclin G2 may exceptionally be a negative regulator since its expression could be induced by DNA damage and the VHL tumor suppressor protein. Furthermore, down-regulated cyclin G2 was detected in oral squamous cell carcinomas. The current study was aimed at clarifying the effects of cyclin G2 transgene expression on proliferation of cancer cells in vitro.
Methods:
Cyclin G2 cDNA was synthesized by reverse transcription-polymerase chain reaction (RT-PCR) and inserted into the pIRESneo vector at BamH I and BstX I sites to generate the recombinant plasmid pIRES-G2. The pIRES-G2 and pIRESneo plasmids were then individually introduced into HeLa cancer cell line through lipofectamine mediated transfection. After two weeks' selection in culture medium containing G418, the number of colonies was counted and the transfectant cells were morphologically observed.
Results:
The colony-forming efficiency of the cells transfected with pIRES-G2 construct was much lower compared with that with the control parental vector pIRESneo. The colony numbers were 76.7 +/- 24.8 and 18 +/- 10.4 in control and experimental groups, respectively, with a colony forming rate of 23.4% in the pIRES-G2 group. Furthermore, pIRES-G2 transfected cells showed a senescent morphology.
Conclusion:
Ectopic overexpression of cyclin G2 in cancer cell line HeLa could inhibit cell proliferation significantly.
Insights
Cyclin G2, a cell cycle regulator, was investigated for its impact on cancer cell proliferation. Overexpressing cyclin G2 significantly inhibited cancer cell growth and induced senescence in HeLa cells.
Area of Science:
- Molecular Biology
- Cell Biology
- Oncology
Context:
- Cyclins are key regulators of the cell cycle, typically promoting proliferation.
- Cyclin G2 is unique, potentially acting as a negative regulator, with expression induced by DNA damage and VHL.
- Down-regulation of cyclin G2 is observed in oral squamous cell carcinomas, suggesting a tumor-suppressive role.
Purpose:
- To investigate the in vitro effects of cyclin G2 transgene expression on cancer cell proliferation.
- To determine if ectopic cyclin G2 overexpression impacts cancer cell growth and morphology.
Summary:
- Cyclin G2 cDNA was cloned into a pIRESneo vector, creating pIRES-G2.
- HeLa cancer cells were transfected with either pIRES-G2 or the control pIRESneo vector.
- Transfected cells were selected, and colony formation and morphology were assessed.
Impact:
- Ectopic cyclin G2 expression significantly reduced colony-forming efficiency in HeLa cells.
- The study demonstrated a 23.4% colony-forming rate in the cyclin G2 group compared to controls.
- Cells overexpressing cyclin G2 exhibited a senescent morphology, indicating inhibited proliferation.