Co-expression of E2F-2 enhances the p53 anti-cancer effect in human glioma cells
P G Mitlianga1, A P Kyritsis, C Gomez-Manzano
1Department of Neuro-Oncology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
Abstract:
Gliomas are highly resistant to conventional treatment. Improved knowledge of the molecular defects of glioma cells offers new avenues for the development of gene therapy strategies. Transfer of the p53 gene has proven effective in suppressing proliferation in human glioma cell lines. However, several human glioma cell lines are resistant to p53-induced cell death. The E2F family of transcription factors are pivotal for the regulation of cell-cycle and cell-death related genes in gliomas. In the present study, we sought a more effective strategy for glioma treatment by examining the therapeutic potential of the simultaneous transfer of p53 and E2F-2 to gliomas. Trypan blue cell viability assays and flow cytometric cell-cycle analysis demonstrated that the transfer of both p53 and E2F-2 induced cell death in D-54 MG, a p53-resistant glioma cell line. In addition, transfer of E2F-2 did not interfere with the apoptotic properties of exogenous wild-type p53 in U-251 MG cells. Finally, the expression of E2F-2 in D-54 MG cells suppressed the expression of the apoptotic molecule mdm-2 induced by exogenous p53 in these cells. These results show that co-expression of E2F-2 and p53 enhances the anti-cancer effect of p53 in gliomas.
Insights
Gene therapy combining p53 and E2F-2 shows promise for treating resistant gliomas. Co-expression of these genes enhances p53
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Gliomas exhibit resistance to conventional therapies.
- Understanding molecular defects in glioma cells is crucial for developing novel gene therapy strategies.
- While p53 gene transfer can inhibit glioma cell proliferation, some cell lines are resistant to p53-induced apoptosis.
Purpose of the Study:
- To investigate the therapeutic potential of simultaneously transferring p53 and E2F-2 genes in glioma treatment.
- To determine if combined gene transfer can overcome p53 resistance in glioma cells.
Main Methods:
- Utilized trypan blue cell viability assays to assess cell death.
- Employed flow cytometric cell-cycle analysis to evaluate cell-cycle progression.
- Examined the expression of apoptosis-related molecules, including mdm-2.
Main Results:
- Simultaneous transfer of p53 and E2F-2 induced cell death in the p53-resistant D-54 MG glioma cell line.
- E2F-2 transfer did not impede the apoptotic effects of exogenous p53 in U-251 MG cells.
- E2F-2 expression in D-54 MG cells suppressed p53-induced mdm-2 expression.
Conclusions:
- Co-expression of E2F-2 and p53 enhances the anti-cancer efficacy of p53 in gliomas.
- This combined gene therapy approach offers a potential strategy to overcome p53 resistance in glioma treatment.
