The Expression And Clinical Significance Of Nucleostemin Gene In Some Tumor Cells And In Alimentary Canal Cancer

Objective To establish the method of RT-PCR, real-time PCR and nested RT-PCR to detect expression of Nucleostemin(NS) in various tumor cells and alimentary canal cancer , and to analyze the clinical significance for diagnosing alimentary canal cancer.Methods Tumor cell lines (SGC,A549,D95,SW480,U937,PC3) were cultured, cancer tissues, paraneoplastic tissue and the corresponding peripheral blood from patients of gastric cancer, colon carcinoma or rectum carcinoma were collected, and paraneoplastic lymph nodes were collected from patients with gastric cancer. The total RNA was extacted. The expression level of NS in tumor cell lines, peripheral blood and cancer tissues from patients of the cancers was detected by real-time PCR and RT-PCR . 30 months after operation, health status of all the patients was invetigated. The death rate was calculated. The expression of NS in mononuclear cells from peripheral blood of the patients with alimentary canal cancer was analysised by RT-PCR and nested RT-PCR .Results NS gene was strongly expressed in SGC , U937, SW480, PC3, F6, hBMMSC, A549 and D95. NS gene was expressed in the cancer tissues from 90%(27/30) patients with gastric cancer, and it was also expressed in 87.5%(14/16) paraneoplastic lymph nodes from the patients with gastric cancer. but it was expressed in paraneoplastic tissue from only 3.3% (1/30)patients with gastric cancer. The expression of NS gene was found in cancer tissue from 5 of 6 patients with rectal cancer, and all the patients with colon carcinoma.. The results of real-time quantitative PCR showed that NS gene was expressed more highly in cancer tissues than that in paraneoplastic tissues from the patients with gastric cancer, rectal cancer and colon carcinoma. The expression level of NS gene was uncorrelated to development stage of alimentary canal cancer, but it was correlated to the stage of differentiation. The expression of NS gene in the earlier stage of differentiation is higher than that in the advanced stage. NS gene could not be detected in mononuclear cells from peripheral blood of the patients with alimentary canal cancer and the healthy persons by RT-PCR, but by nested PCR, NS gene can be detected in mononuclear cells from peripheral blood of 60% (18/30) of awaiting operation patients with gastric cancer, 71.4% (5/7) of awaiting operation patients with colon caicinoma and 83.3% (5/6) of awaiting operation patients with rectal cancer. 1 week after operation, the positive rate of NS in mononuclear cells from peripheral blood of patients with gastric cancer, colon carcinoma and rectal cancer is 43.3% (13/30), 71.4% (5/7), 33.3% (2/6) respectively. All the patients were divided into 6 groups according to cancer and the results of nested PCR: Three and positive groups and three corresponding negtive groups. The death rate of every positive group is higher than that of the corresponding negtive group.Conclusion Up regulation of the expression of NS might play an important role in the tumorigenesis and development of alimentary canal cancer, The real time PCR, RT-PCR and nested PCR for NS might provide a novel methd for diagnosis of alimentary canal cancer. Nested PCR for NS is a potential and useful method to detect micro reliquus focus of infection in peripheral blood from patients of alimentary canal cancer, and can be used to propose palindromia of alimentary canal cancer. In peripheral blood from the patients with gastric cancer, colon carcinoma, rectum carcinoma,The expression of NS gene could be detected by nested RT-PCR, but could not be detected by RT-PCR, Detection of expression of NS by nested PCR in peripheral blood from the patients will help to diagnosis for alimentary canal cancer.