Related Experiment Videos
Carcinoma cell lines become sensitive to DNA-damaging agents by the expression of the adenovirus E1A gene
R Sánchez-Prieto1, M Quintanilla, A Cano
1Dpto. Patologia, Clinica Puerta de Hierro, San Martin de Porres, Madrid, Spain.
Abstract:
Squamous cell carcinomas can show different oncogenic alterations, histological patterns, and an unpredictable clinical behavior. We previously reported that the adenovirus E1a gene may induce sensitivity to DNA-damaging agents in mouse keratinocytes. In order to study whether E1a expression could be used as a therapeutic agent in different malignant cell lines carrying mutations on the p53 gene and other oncogenic alterations, we transfected and infected several murine and human carcinoma cell lines (HaCa4; MSC11A5; HeLa) with vectors containing the 13S or 12S E1a region. We evaluated the sensitivity to cisplatin (CDDP), doxorubicin (DOX) and gamma irradiation (RX) by the crystal violet method. The induction of apoptosis was assessed by flow cytometry and presence of DNA ladders in agarose gels. The expression of E1a and the tumor suppressor p53 protein was analysed by Western blotting. The carcinoma cell lines expressing E1a were about four- to tenfold more sensitive to CDDP and RX, respectively, than the control cells. Moreover, the reduction in cell viability and cell growth after exposure to CDDP or RX was very significant in the carcinoma cells expressing E1a. With these results, we conclude that expression of E1a may confer great sensitivity to DNA-damaging agents on squamous cell carcinoma cells independently of the p53 protein status and other oncogenic alterations.
Insights
Adenovirus E1a gene expression enhances squamous cell carcinoma sensitivity to DNA-damaging chemotherapy and radiation. This therapeutic approach is effective regardless of p53 gene mutations or other oncogenic alterations.
Area of Science:
- Oncology
- Molecular Biology
- Virology
Background:
- Squamous cell carcinomas exhibit diverse oncogenic alterations and unpredictable clinical behavior.
- Previous research indicated adenovirus E1a gene can induce DNA-damaging agent sensitivity in mouse keratinocytes.
Purpose of the Study:
- To investigate if adenovirus E1a gene expression can serve as a therapeutic agent in malignant cell lines with p53 mutations and other oncogenic alterations.
- To evaluate the impact of E1a expression on the sensitivity of various carcinoma cell lines to DNA-damaging agents.
Main Methods:
- Transfection and infection of murine and human carcinoma cell lines (HaCa4, MSC11A5, HeLa) with vectors containing adenovirus E1a gene regions (13S or 12S).
- Assessment of sensitivity to cisplatin (CDDP), doxorubicin (DOX), and gamma irradiation (RX) using the crystal violet method.
- Analysis of apoptosis induction via flow cytometry and DNA laddering, and evaluation of E1a and p53 protein expression by Western blotting.
Main Results:
- Carcinoma cell lines expressing E1a demonstrated a four- to tenfold increase in sensitivity to CDDP and RX, respectively, compared to control cells.
- Significant reduction in cell viability and growth was observed in E1a-expressing carcinoma cells upon exposure to CDDP or RX.
- E1a expression enhanced sensitivity to DNA-damaging agents independently of p53 protein status and other oncogenic alterations.
Conclusions:
- Adenovirus E1a gene expression can significantly enhance the sensitivity of squamous cell carcinoma cells to DNA-damaging agents like cisplatin and gamma irradiation.
- This therapeutic strategy shows promise for treating squamous cell carcinomas, offering a potential treatment option irrespective of specific genetic mutations like p53 alterations.