Apoptosis in SW480 Cells Induced by Combining Oncolytic Adenovirus ZD55-IL-24 with Histone Deacetylase Inhibitor SAHA

Abstract: To investigate the anti-tumor effects in colorectal cancer cell line SW480 in vitro by combining oncolytic adenovirus ZD55-IL-24 with suberoylanilide hydroxamic acid (SAHA)， MTT assay and crystal violet assay were used to determine the growth inhibition effect of single or combination therapy on colorectal cancer cell line SW480 and normal human lung epithelial cell line Beas-2B. After Hoechst33342 staining， the morphological changes of apoptosis in treated cells were observed under fluorescence microscope. And flow cytometry assay was used to quantify apoptosis. The expression level of IL-24 protein was assayed by Western blot. The results of MTT and crystal violet staining showed that the growth inhibition of SW480 cells treated with the combination of ZD55- IL-24 and SAHA were more obvious than that in ZD55-IL-24 group or SAHA group alone. Four days after administration of 10 MOI ZD55-IL-24 and 0.5 μmol/L SAHA， the cell viability rate of SW480 cells was only 12%， which was significantly lower than that of cells treated only by 10 MOI ZD55-IL-24 (40%， P<0.05). In contrast， Beas-2B cells were spared from inhibition of combined treatment (P<0.05). Hoechst33342 staining and flow cytometry also confirmed that there were much more apoptotic SW480 cells in combinational treatment group. In addition， IL-24 protein was effectively expressed in SW480 cells infected with ZD55-IL-24 alone or treated with ZD55-IL-24 plus SAHA.

CSTR: 32200.14.cjcb.2012.01.0008