Inhibitory Effect Of Recombinant Plasmid PhTERT-PE38KDEL Combined Bortezomib On Pancreatic Tumors In Athymic Mice

ObjectiveTo explore the inhibiting effects of recombinant plasmid phTERT-PE38KDEL and bortezomib on transplanted pancreatic tumour in athymic mice.MethodsPancreatic carcinoma cell line MiaPaCa2was seeded subcutaneously into the BalB/C nude mice,and subcutaneous pancreatic carcinoma xenografts model was established.By abdominal cavity administration and intratumoral injection,the mice bearing tumor were treated with bortezomib in combination with recombinant plasmid of phTERT-PE38KDEL.The tumour volume and weight were detected,and the tumour inhibitory rate was calculated. Survival periods of nude mice in each group were also compared. The tissues obtained from heart,liver and kidney stained by hematoxylin-eosin were observed under optic microscope.The Proliferating Cell Nuclear Antigen (PCNA) and Micro vascular Density(MVD)were examined by immunohistochemistry method.Cell apoptosis in tumour tissues was observed by TUNEL method and apoptosis index was calculated. The tumor cell apoptosis rate and cell cycle kinetics of each group were detected by flow cytometry.ResultsFour groups of xenograft models of human pancreatic carcinoma were established successfully.The tumour volume and weight of combined therapeutic group(Group A)was obviously smaller than that of gene therapeutic group(Group B)、 chemotherapy group(Group C)and control group(Group D) at any time point (P <0.01). Compared with Group D,the inhibitory rate to tumor growth in Group A、B、 C were68.98%、51.44%and16.39%, respectively. The necrosis and apoptosis were occurred more frequently in Group A.There were no obviously abnormal changes in heart,liver and kidney. The PCNA examined by immunohisto-chemistry in tumour tissues of Group A were lowed sharply and MVD declined to7.78±0.96.Apoptosis cells examined by TUNEL were increased in tumour tissues of Group A with AI of40.41%±3.24%,which had significant differences(P<0.01). The proportion of G1/S phase cells of group A was significantly higher than other groups. while the proportion of G2/M phase cells was lower than other groups,which indicated that the combination therapy could inhibit DNA replication of tumor cell,so that more tumor cells were stagnation in cell division prophase. ConclusionsDouble phTERT-PE38KDEL and bortezomib have antitumor effect in vivo and combined therapy have stronger antitumor effect, which make no obvious damage to normal tissue and have good security and targeting.