Relationship Between The Expressing Of PCNA, Ki-67,Nanog,Oct-4in Gastric Cancer And Recurrence Or Metastasis

Background and PurposeGastric cancer is one of the most common malignancies with the characteristics of high malignancy, strong invasiveness and drug resistance. In recent years, the developments of cancer stem cell theories have taken new ideas for the treatment of malignant tumors. However, limited researches have been done in the field of gastric cancer. Markers of embryonic stem cell, such as Nanog, Oct-4are also expressed in cancer stem cells and their expression levels have close correlation with the cancer formation, reproduction and transference. But the relationship between the prognosis of gastric cancer and the expression levels of Nanog and Oct-4is not clear. PCNA and Ki-67are common reproduction biomarkers in malignant tumor. But, the relationship between the expression of PCNA, Ki-67and the prognosis of gastric cancer is unclear. And this research examined the expression of stem cell markers of Nanog, Oct-4and proliferative markers of PCNA and Ki-67in gastric cancer tissues in order to explore the relevance of their expressions and clinical pathology factors such as pathological stage, invasion, and lymphatic metastasisand disease-free survives metastatic sites.The internal relations between Nanog, Oct-4and PCNA, Ki-67are also preliminarily explored.in order to provide some clinical basis for the diagnosis and prognosis of gastric cancer. Materials and MethodsSixty-nine patients with gastric cancer from January1,2007, through January1,2008were included in the retrospective study. All these patients had accepted adjunctive chemotherapy followed by surgery. The protein expression levels of Nanog, Oct-4, PCNA and Ki-67were detected by the Elivison immunohistochemistry method. The differences of Nanog, Oct-4, PCNA and Ki-67protein expression levels in gastric cancer tissue were evaluated by Chi-square test or Chi-square test after correction. Kaplan-Meier method was used for analysis of overall survival. The Log-rank test was used for univariate prognostic analysis and Cox proportional hazards regression analyses was used for multivariable prognostic analysis, then use Sperman analyze therelationship between these markers.ResultExpression rates in gastric cancer of Nanog, Oct-4, PCNA, Ki-67were24.6%,52.2%,52.2%and37.7%. Analysis of a single marker, Clinicopathological factors: Oct-4negatively correlated with the degree of differentiation (p=0.041,x2=4.182). Between the different PCNA expression group, the T stage was statistically significant difference (p=0.005,x2=7.951). Between indicators of PCNA, Oct-4expression and DFS showed a negative correlation (p values were0.043and0.032, respectively,x2values were4.083and4.619, respectively). In different Nanog and Ki-67expression group, the difference of DFS was not statistically significance, but the positive expression group had a lower DFS. Although there was no statistically significant relationship between the recurrence rate and these markers, but the patient with positive expression may have higher metastasis and recurrence rate. Packet analysis:The degree of differentiation in Nanog and Oct-4positive expression group was higher than the other groups (p=0.027,x2=7.234), but the analyze of DFS had no statistically significant difference. PCNA, Ki-67both positive group had lower DFS than the other groups (p=0.017,x2=8.167), and compared with T stage in positive expression group, negative expression group was earlier (p=0.018,x2=8.016). Joint analysis of the four indicators found it was shorter that the DFS in the more indicator expression groups (p=0.028,x2=10.882).Multivariate analysis found that T stage, lymph node metastasis and Nanog expression were independent risk factor for DFS (p<0.05). Correlation analysis, Nanog was positive correlation with Oct-4and PCNA. PCNA and Ki-67was positive relevant too.(p<0.05).ConclusionNanog, Oct-4, PCNA, Ki-67independent or combined detection may become a judgment postoperative DFS predictor, and the more the expression of indicators may mean that the worse DFS. The combined detection may be more conducive to prognosis. PCNA alone or joint with Ki-67detection may related to the ability of tumor invasion,these markers may be indicators of proliferation and invasion capacity in early gastric cancer. Correlation analysis indicate that there may be a relationship between Nanog and Oct-4; Naong and PCNA; PCNA and Ki-67, and may closely related to the occurrence and development of tumors.