OBJECTIVETo further explore the effect of annexin I on the tumor growth of human pancreatic cancer in nude mice.

METHODSTo knock down the expression of annexin I in pancreatic carcinoma cells by RNAi. A nude mouse model of human pancreatic cancer was established by subcutaneous inoculation of human pancreatic cancer cell line Suit-II cells. The effect of annexin I on tumor growth was assessed by tumor growth curve and tumor weight records, and Westen blot and flow cytometry were used to examine the expression of annexin I after annexin I-knocking down.

RESULTSThe results of Western blot revealed that the expression of annexin I was significantly decreased in Suit-II cells transfected with pSilencer-annexin I-siRNA1, and almost completely inhibited in the cells transfected with pSilencer-annexin I-siRNA2 and pSilencer-annexin I-siRNA3. The growth of tumors transfected with annexin I-siRNA2 and annexin I-siRNA3 was inhibited by 76.6% and 68.4%, respectively, in comparison with that of tumor from the parent Suit-II cells. At 44 days after tumor cell inoculation, the tumor weight was 0.8987 g (transfected with annexin I-siRNA2) and 0.8992 g (transfected with annexin I-siRNA3), significantly lower (P < 0.001) than that of tumor from parent Suit-II cells (2.5866 g) and transfected with annexin I-siRNAN (2.4070 g).

CONCLUSIONannexin I promotes the growth and proliferation of pancreatic carcinoma cells in vivo and increases the ability of tumor formation in nude mice. The results of this study support that annexin I may become a potential target in gene therapy for this disease.