Detection of telomerase gene expression In the peripheral blood mononuclear cells in patients with colorectal carcinoma by real-time quantitative telomeric-repeat amplification protocol assay

Objective To investigates the gene expression of telomerase by real-time quantitative telomeric-repeat amplification protocol assay (RTQ-TRAP) in the peripheral blood mononuclear cells (PBMC) of colorectal carcinoma patients and the relationship between the telomerase gene expression in PBMC and clinicopathological features. Methods Peripheral blood samptes were collected from 71 colorectal carcinoma patients, 20 benign colorectal disease patients and 25 normal controls. The telomerase gene expression in PBMC was measured by RTQ-TRAP, and serum CEA in colorectal carcinoma patients was measured by chemiluminescence immunoassay. Results The gene expression of telomerase in PBMC was positive in 50 out of 71 cancer patients (70. 4% ) , 1 out of benign patients (5. 0% ), respectively. The difference of the telomerase gene expression of PBMC in benign colorectal diseases and cancer patients was significant (χ2 = 24. 521, P < 0. 001 ). There was no significant association between the expression of telomerase and patient's gender, age, Dukes stage, and tumor site. The positive rate of CEA in colorectal carcinoma patients was not significantly higher than positive rate of telomerase gene expression(χ2 = 2. 286,P = 0. 125). Conclusions The RTQ-TRAP method is highly accurate and sensitive in measuring telomerase gene expression. The detection of telomerase gene expression in PBMC of colorectal carcinoma patients is a simple and useful molecular marker for the diagnosis of colorectal carcinoma. Key words: Colorectal neoplasms;  Telomerase;  Leukocytes, mononucleur;  Polymerase chain reaction;  Gene expression