Adenovirus-mediated ING4Expression Suppresses Colorectal Cancer Cell Growth And Its Molecular Mechanism

Object: To explore the effect of Adenovirus-mediated ING4expression suppressingcolorectal cancer cell growth and its molecular mechanism. Methods: Recombinantadenovirus Ad-ING4was transfected into the human embryonic kidney293(QBI-293A)cells. The adenovirus completed the amplification in QBI-293A cells and the titrationwas also detected. The expression of ING4in QBI-293A cells and SW1116colorectalcarcinoma cells was detected by reverse transcription-polymerse chain reaction(RT-PCR). In vitro the SW1116colorectal carcinoma cells were randomly divided intofive groups: PBS negative control group(PBS group), idling adenovirus group (Ad-GFPgroup), adenovirus-mediated ING4group (Ad-ING4group), PTX group (PTX group),Ad-ING4combined with PTX group (combination group).The expression of ING4protein in SW1116colorectal carcinoma cells and the expression of STAT3,pSTAT3,Ki-67protein were detected by western blot. The effect of enhancedgrowth-suppressing and apoptosis-inducing by Ad-ING4on SW1116colorectalcarcinoma cells were analyzed by MTT assay and flow cytometry. In vivo groups aresimilar with in vitro. The human colorectal carcinoma model was established withSW1116cells in athymic nude mice.The tumor volumes were measured dynamically.The inhibition rates of tumor were calculated. The tumors were observed by HE stainingmethod. Immunohistochemistry for the detection of protein expression: ING4,STAT3,pSTAT3, Ki-67. Results:1, Ad-ING4gene can proliferate in QBI-293A cells, thetitration was (1-2)×109pfu/ml.2, Infected with Ad-ING4gene in SW1116colorectalcarcinoma cells, ING4gene can be expressed by RT-PCR and western blot. In vitroAd-ING4can enhance growth-suppressing and apoptosis-inducing in human SW1116 colorectal carcinoma cells. It showed that the expression of pSTAT3and Ki-67inAd-ING4group, PTX group, combination group of SW1116colorectal carcinoma cellswas significantly decreased, comparing with PBS group, Ad-GFP group (P<0.05), theexpression of STAT3was constant.3, In vivo Ad-ING4gene can inhibit the growth ofcolorectal carcinoma transplanted tumor in athymic nude mice significantly, comparingwith PBS group, Ad-GFP group (P<0.05), and the combination group effect is moresignificant than that of Ad-ING4group, PTX group. It showed that the expression ofpSTAT3and Ki-67in Ad-ING4group, PTX group, combination group in tumor tissuewere significantly decreased, comparing with PBS group, Ad-GFP group (P<0.05), theexpression of STAT3was constant. The positive expression of pSTAT3and Ki-67inAd-ING4group,PTX group and combination group was decreased byImmunohistochemistry, the positive expression of STAT3was constant. Conclusion:1,Ad-ING4had significant effect in suppressing cell growth and inducing cell apoptosisin SW1116colorectal carcinoma cells, and had significant effect in suppressingcolorectal carcinoma transplanted tumor growth in athymic nude mice.2, Ad-ING4hadpotent effect in down-regulating the expression of pSTAT3, Ki-67, which may be one ofimportant mechanisms involved in its anti-tumor effect.3, Ad-ING4combined withPTX had more potent effect in suppressing cell growth and inducing cell apoptosis inSW1116colorectal carcinoma cells and colorectal carcinoma transplanted tumor growthin athymic nude mouse, which indicating ING4has the effect of chemotherapysensitivity.