RESUMO
Objectives To establish real-time fluorenscence quantitative polymerase chain reaction ( RFQ-PCR ) for measurement of the expression level of guanylyl cyclase-C(GC-C) in the Peripheral blood mononuclear cell(PBMC)in 30 blood donors, 10 cases colorectal cancer tissue and 1 case T84 human colon cancer cell line. Methods Specific primers and TaqMan probe have been designed,and fluorenscence of the PCR product was detected continuously during amplification. According to the standard curve created by plasmid DNA, the expression level of GC-C in clinical samples has been determined using software, and the results were presented as the ratios of GC-C mRNA to?2-microgluobulin(?2M)mRNA. Results The detection range of the assay was from 101 pg/ml to109pg/ml,the coefficient of variation values of both intra-experimental and inter- experimental reproducibility were 6. 87% to 11. 12% and 8. 86% to 15. 19% . None of 30 blood donors and 11 benign intestinal patients expressed GC-C mRNA,it was expressed in 31/37 colorectal cancer patients. The expression level of GC-C mRNA in colorectal cancer patients was 0. 88?0.06,and the expression level of its in colorectal carcinoma tissue and T84 cells were 0. 86?0.07/ug tissue and 0.0082/per cell. Conclusions This assay had high sensitivity,specificity and reproducibility.