OBJECTIVE: To determine the effect of Ad-E1A gene therapy on the radiosensitivity of nasopharyngeal carcinoma cell by downregulating the expression of VEGF in vitro. METHOD: The human nasopharyngeal carcinoma CNE-2Z cell lines were investigated. The recombinant adenovirus vector containing E1A gene was used for this study. After CNE-2Z cells was treated with PBS, Ad-beta-gal and Ad-E1A for 48 h, the three groups were irradiated in different doses at 0, 2.4, 6, 8 and 10 Gy, the cytotoxicity was determined by MTT assay and cell cycle was analysis by flow cytometry. The VEGF expression were evaluated by RT-PCR assay and immunocytochemical analysis. RESULT: Significant cell deaths by IR were observed in a dose dependent manner in the three group CNE-2Z cells. After transduction of the E1A gene into CNE-2Z cells, the sensitivity of these cells to radiation was enhanced than the PBS treated group and Ad-beta-gal treated group. Cell growth inhibition in Ad-E1A group by IR was strongly enhanced than Ad-beta-gal treated group and PBS treated group. RT-PCR assay and immunocytochemical analysis showed VEGF expression was downregulated in Ad-E1A treated group. CONCLUSION: E1A gene therapy can effectively enhance the nasopharyngeal carcinoma cell sensitivity to the radiotherapy by down-regulating VEGF expression. These findings may pave the way for efficient radiation-gene therapy to NPC in future.
OBJECTIVE: To determine the effect of Ad-E1A gene therapy on the radiosensitivity of nasopharyngeal carcinoma cell by downregulating the expression of VEGF in vitro. METHOD: The humannasopharyngeal carcinoma CNE-2Z cell lines were investigated. The recombinant adenovirus vector containing E1A gene was used for this study. After CNE-2Z cells was treated with PBS, Ad-beta-gal and Ad-E1A for 48 h, the three groups were irradiated in different doses at 0, 2.4, 6, 8 and 10 Gy, the cytotoxicity was determined by MTT assay and cell cycle was analysis by flow cytometry. The VEGF expression were evaluated by RT-PCR assay and immunocytochemical analysis. RESULT: Significant cell deaths by IR were observed in a dose dependent manner in the three group CNE-2Z cells. After transduction of the E1A gene into CNE-2Z cells, the sensitivity of these cells to radiation was enhanced than the PBS treated group and Ad-beta-gal treated group. Cell growth inhibition in Ad-E1A group by IR was strongly enhanced than Ad-beta-gal treated group and PBS treated group. RT-PCR assay and immunocytochemical analysis showed VEGF expression was downregulated in Ad-E1A treated group. CONCLUSION: E1A gene therapy can effectively enhance the nasopharyngeal carcinoma cell sensitivity to the radiotherapy by down-regulating VEGF expression. These findings may pave the way for efficient radiation-gene therapy to NPC in future.