ABSTRACT
Objective To study on the expression and clinical significance of programmed death ligant 1 (PD-1) in the development of colorectal cancer.Methods Flow cytometry (FCM) was used to detect and analyse the positive expression rate of PD-1 on CD3+ T cells in peripheral blood samples of 88 colorectal cancer patients and 74 healthy volunteers,and in sixpairs of tissue specimens (colorectal cancer tumor and adjacent normal tissues).Colon cancer tumor-bearing mice models were constructed by subcutaneous implantation of murine colon cancer cell line CT26,and the changes of positive expression rate of PD-1 on CD3+ T cells in spleens and transplanted tumor tissues were also detected by FCM in different time points during five,eight,11,14,17,20 days after the model was constructed.Finally,the experimental results were analyzed by t test or variance analysis.Results The positive expression rate of PD-1 on CD3+ T cells in peripheral blood of colorectal cancer patients was significantly higher than that in healthy volunteers ((29.25 ± 9.37) ％ vs (19.35 ± 7.37) ％,t =7.375,P＜ 0.01),and the positive expression rates were significantly increased in colorectal cancer patients with lower degree of differentiation,lymph node metastasis and higher Duke's stage.The positive expression rate of PD-1 on CD3+T cells was significantly higher in colorectal cancer tissues compared to adjacent normal tissues ((52.38±12.28)％ vs (24.72±4.78)％,t=5.143,P＜0.01).In the colon cancer tumor-bearing mice models,along with the growth of transplanted tumors,PD-1 positive expression rates on the CD3+T cells of tumor-bearing mice spleens and transplanted tumors showed a gradually rising tendency.From the eighth day to the 20th day after subcutaneous transplanted colon cancer cells,the average positive expression rate of PD-1 on the CD3+T cells of tumor-bearing mice spleens rose from (52.83±6.17)％ to (77.30± 6.84) ％,and the average positive expression rate of transplanted tumors rose from (60.43 ± 2.77)％ to (90.47±4.31) ％.Conclusion There is a correlation between the expression of PD-1 on mature T cell surface and the development of colorectal cancer,and the high specific expression of PD-1 may promote the invasion and metastasis of colorectal cancer.
ABSTRACT
Objective:To establish the best way of tumor-bearing nude mice model with epithelial ovarian adenocarcinoma cell lines. Methods:CAOV3 (wall-attached cell) and COC2 (suspended cell) cell lines were transplanted subcutaneously to the nude mice by injection with different cell concentration or tissue block implantation. Results:The rate and time of tumor formation in the two cell lines were not related to cell concentration in the range from 5?10 6/0.2 ml to 6?10 7/0.2 ml. Time of tumor formation was earlier(especially in the manner of tissue block implantation),the successful rate of tumor formation was higher and the speed of tumor growth was relatively retarded in the nude mice bore CAOV3 cell line's tumor than that in COC2 cell line's. But once tumors were formed in nude mice bearing COC2 cell line, the mice died too fast to make experiment because of very quick speed of tumor growth. Conclusion:Wall-attached cell line, tissue block implantation with trocar may be the best way to establish tumor-bearing nude mice model in epithelial ovarian adenocarcinoma cell lines.