Each of the tumor items was weighed and adjusted to be 150 mg with scissors. P-selectin Mab treated group was lower than that in the PBS treated group (with tumors). The NK activity of normal mice increased over time. The immune functions (T, B cell function, NK activity) of the tumor group in the 6th week were significantly lower than those in the 4th week, but the switch was attenuated by P-selectin Mab. Summary: P-selectin Mab could suppress the metastasis of gastric malignancy with no adverse effect on sponsor immune function. Intro Gastric carcinoma is one of the most frequent tumors in China. Tumor metastasis is very common clinically. Cell adhesion molecules have been implicated to be crucial elements in the process of metastasis[1-28]. P-selectin is an adhesion molecules that mediates the cell to cell connection of platelets and endothelial cells with neutrophils and monocytes as well as tumor cells[29]. Our earlier study Ace shows that P-selectin manifestation is related to aggressive behavior, dissemination and poor prognosis of human being gastric carcinomas, and P-selectin monoclonal artibody can inhibit gastric carcinoma metastasis[30-32]. The present study was performed to investigate effects of P-selectin monoclonal antibody on metastasis and immune function in SCID mouse metastaic models of human being gastric cancer constructed by orthotopic implantation of histologically intact tumor cells. MATERIALS AND METHODS Animal model Forty-eight male SCID mice from Shanghai Malignancy Institute were 7-8 wk aged with excess weight of 20-25 g. Human being gastric malignancy SGC-7901, a poorly-differentiated adenocarcinoma collection, was originally derived from a primary tumor and managed by passage in nude mice subcutaneously. SCID mice were randomly divided into experimental group (= 24) and normal group (= 24). Animal models in experimental group were made using orthotopic implantation of histologically intact cells of human being gastric carcinoma[33]. Tumors were resected aseptically. Necrotic tumor cells were BMT-145027 removed and the remaining non-necrotic tumor cells were minced into items about 5-7 mm in diameter in Hanks balanced salt solution. Each of the tumor items was weighed and modified to be 150 mg with scissors. Mice were anesthetized with 4.3% trichloraldehyde hydrate and an incision was made through the remaining upper abdominal pararectal collection and peritoneal cavity was carefully exposed and a part of the serosal membrane in the middle of the greater curvature of the glandular belly was mechanically injured by using scissors. A tumor piece of 150 mg was fixed on each hurt site of the serosal surface. The belly was then returned to the peritoneal cavity, and the abdominal wall and pores and skin were closed. 3 d later on, all animals implanted with intact tumor cells received i.v. injection of PBS (group3, = 12) or P-selectin antibody (Suzhou Medical College; 100 g/injectiom; group4, = 12) twice weekly for 3 wk. Animals in normal group received i.v. injections of PBS (group1, = 12) or P-selectin antibody (100 g/injection; group2, = 12). Sample collection and pathological exam Two mice in each group were sacrificed randomly on weeks 1, 2, and 4. The remaining animals were sacrificed BMT-145027 at 6th week and the tumors growing on the belly wall were removed and examined histologically. Cells from all organs were examined for metastasis after careful macroscopic exam. The spleen of mice was harvested for detection of immune function. Lymphocyte transformation test Using 3H TdR infiltration method, T cell transformation function was recognized with Con A (5 g/ml, Sigma), B cell function with LPS (50 g/ml, Sigma). The spleen was made into suspension and mononuclear cells were acquired with lymphocyte-separating fluid. The cell suspension was modified to 2 106/mL with RPMI 1640 liquid comprising 10% calf serum (GIBCO). Then 200 L of the cell suspension was put into each well in 96-well plates. One plate was for Con A group, and another plate for LPS group. There were bad control group and experimental group for Con A or LPS group respectively, and each test had 5 repeated wells and was cultivated under 5% CO2 at 37 C. The cell suspension in Con A group was BMT-145027 cultivated for 3 d, while it was carried out for BMT-145027 5 d in Con A group. All wells were added up 3H TdR 16 h before the end of cultivation. They were collected in filtration paper, and given 0.5 mL of scintillating liquid to detect cpm value with -scintillator, which was presented with SI. SI amounts to cpm of experimental group/cpm of vacant group. NK activity NK activity was recognized from the 4 h LDH launch method. NK cell activity (%) = (Experimental organizations OD-Natural launch groups OD)/(Maximum launch groups OD-Natural launch organizations OD) Statistical methods Comparisons among organizations were performed from the students test and test. A value of.