B7 and ICOS mRNA expression in human colorectal carcinoma

    XIAO Juª²Xiang, LAI Baoª²Chang, ZHU Juan, LI Li, BAI Peiª²Song, WANG Yiª²Li

    1Department of Oncology, First Hospital, 2School of Life Science & Technology, Xi¡¯an Jiaotong University, Xi¡¯an 710061, China

    ¡¾Abstract¡¿ AIM: To observe the tumor associated B7 family molecules mRNA expression on human colorectal cancerous tissue by in situ hybridization. METHODS: The mRNA expression patterns of cancer associated B7ª²1, B7H1, B7H2 and ICOS mRNA expression in 22 specimens of human colorectal cancer were monitored by the technique of in situ hybridization (ISH) with the Diogenesª²labeled Oligonucleotideª²probes. RESULTS: B7ª²1, B7H1, B7H2 and ICOS mRNA were detected in both cancer cells and tumor infiltrating lymphocytes (TILs). The mRNA expression level of these molecules in tumor cells was higher than that in TILs (0.76¡À0.54-1.62¡À0.82 vs 0.38¡À0.19-0.65¡À0.33, P<0.01). There was no correlation between the expression level of tested B7 family molecules and the sex, age, differentiation status of cancer and regional lymph nodes metastasis of the patients. CONCLUSION: Th2 cytokine predominant in tumor microenvironment may be related to the expression of B7H1 and B7H2 coª²signal molecules on tumor cells and TILs. ......