ObjectiveTo investigate the clinical significance of CK20 mRNA expression in blood of patients with colorectal cancer. MethodsThe expressions of CK20 mRNA in blood of twenty healthy volunteers, ten patients with colorectal polyp and sixtyone patients with colorectal cancer were detected by RT-PCR. ResultsThe positive rate of CK20 mRNA in peripheral venous blood and portal venous blood of patients with colorectal cancer were 41.0%(25/61) and 45.9%(28/61), which was not significantly different (Pgt;0.05). The expression of CK20 mRNA in patients with colorectal cancer was associated with clinical TNM stage of tumor, local lymph node metastasis, distance metastasis, and the depth of invasion (Plt;0.05). No expression of CK20 mRNA was detected in blood of twenty healthy volunteer’s and ten patients with colorectal polyp. ConclusionCK20 is a specific marker for detecting blood micrometastasis of colorectal cancer. The expression of CK20 mRNA in blood of patients with colorectal cancer is related with TNM stage, invasion, and metastasis of colorectal cancer.
Objective To detect the expression of cytokeratin 20 (CK20) mRNA (micrometastasis) in regional lymph nodes and the serum activities of CD4+ cells, CD8+ cells and NK cells, serum levels of IL-2, IL-12 and sIL-2R in peripheral blood of patients with colorectal cancer; and to investigate the relationship between them. Methods Total 281 lymph nodes of 21 patients with colorectal cancer were collected. The positive expression of CK20 mRNA in lymph nodes was detect by reverse transcription-polymerase chain reaction (RT-PCR) and the metastasis in lymph nodes was detected by conventional pathological examination; the serum activities of CD4+ cells, CD8+ cells and NK cells were detected by flow cytometry and serum levels of IL-2, IL-12 and sIL-2R were detected by ELISA method in peripheral blood of patients with colorectal cancer. Results Among the positive metastasis in the 281 lymph nodes of the 21 patients, there were 16 (5.7%， 16/281) lymph nodes in 2 patients detected by pathological examination and 140 (49.8%， 140/281) lymph nodes in 10 patients by RT-PCR. There was a significant difference between the two measures in the aspects of the detection rate and the positive cases of lymph node metastasis in the 21 patients. Before operation, the serum activities of CD4+ cells, CD4+/CD8+ and NK cells, levels of IL-2 and IL-12 in 11 patients whose CK20 mRNA in regional lymph nodes were negative expression were higher than those in the other 8 patients whose lymph nodes metastasis were negative by conventional pathological examination but CK20 mRNA were positive expression （P＜0.05）; and the serum activity of CD8+ cells and level of sIL-2R in the former ones were lower than those in the latter ones （P＜0.05）. The serum activities of CD4+（r＝－0.769） cells, CD4+/CD8+（r=－0.755） and NK cells （r=－0.532）, the levels of IL-2 （r＝－0.834） and IL-12 （r＝－0.819） were negative correlated with the expression of CK20 mRNA （P＜0.05, P＜0.01）; and the activity of CD8+ cells （r=0.562） and level of sIL-2R （r=0.751） were positive correlated with the expression of CK20 mRNA （P＜0.05）. Conclusion The micrometastasis in lymph nodes is correlated significantly with the lower immune function of patients with colorectal cancer.