Vaccinia Virus Mediated Expression of Human APC Induces Apoptosis in Colon Cancer Cells
Sarah Umphress, Tatyana Timiryasova, Takeshi Arakawa, Sandra Hilliker, Istvan Fodor and William Langridge
Mutations in the adenomatous polyposis coli (apc) gene disrupt homeostatic pathways controlling enterocyte cell growth, division and death resulting in adenoma formation leading ultimately to colon carcinoma. A recombinant vaccinia virus containing the human apc gene (rVV-APC) was constructed and its effect on cultured colon cancer cells analyzed. Recombinant vaccinia virus mediated transfer of the apc gene into human SW480, T84 and HCT116 adenocarcinoma cells containing an altered, deleted or full length apc gene respectively, resulted in synthesis of full length APC protein detected by immunoblot analysis. Significant decreases in viability of the virus-infected SW480, T84 and HCT116 cells were detected by TTC assay. The decrease in cell viability correlated with increased levels of apoptotosis measured by cytochemistry, DNA fragmentation analysis, TUNEL assay and flow cytometry. Increases in cell apoptosis were independent of the presence of endogenous apc. The experimental results show that recombinant vaccinia virus containing the apc gene can restore tumor suppressor gene function in human adenocarcinoma cells. This result demonstrates the efficacy of vaccinia virus mediated APC gene transfer as a method for colon cancer therapy.
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