Expression And The Relationship Of P16 Gene, Ki-67 And Mcm2 In Gastric Cancer

Objective: To study the expressions of P16 gene,Ki-67 and Mcm2 in gastric cancer for investigating their roles and their correlation in pathogenesis, progression,invasion and metastasis of in gastric cancer , and provide theoretical evidence for clinicopathological diagnosis and evaluation of prognosis.Methods: Detection of the expression of P16,Ki-67 and Mcm2 in 10 cases of normal gastric mucosa,30 cases of atypical hyperplasia and 64 cases of gastric cancer by using tissue chip technique and immunohistochemical SP methods.Results : (1) Expression rate of P16 nuclear antigen was 80.0%, 63.3% and 37.5% in normal gastric mucosa , atypical hyperplasia and gastric cancer respectively. The positive expression rate of P16 in gastric cancer was significantly lower than in normal gastric mucosa and atypical hyperplasia, and there was a significant difference in positive rates among them. The positive expression rate of P16 in gastric cancer was significantly correlated with differentiated degree, but negative correlated with lymph node metastasis and infiltrative depth. There was no statistical significance such as age, sex and histopathology .(2)The expression of Mcm2 was 20%,33.3% and 57.8% in normal gastric mucosa, atypical hyperplasia and gastric cancer respectively. The positive expression rate of Mcm2 in gastric cancer was significantly higher than in normal gastric mucosa and atypical hyperplasia,and there was a significant difference in positive rates among them. The positive expression rate of Mcm2 in gastric cancer was significantly negative correlated with differentiated degree, but positive correlated with infiltrative depth. There was no statistical significance such as age, sex and, histopathology and lymph node metastasis. (3) The expression of Ki-67 was 10%,26.7% and 53.1% in normal gastric mucosa, atypical hyperplasia and gastric cancer respectively. The positive expression rate of Mcm2 in gastric cancer was significantly higher than in normal gastric mucosa and atypical hyperplasia,and there was a significant difference in positive rates among them. The positive expression rate of Ki-67 in gastric cancer was significantly negative correlated with differentiated degree, but positive correlated with infiltrative depth and lymph node metastasis. There was no statistical significance such as age, sex and histopathology. (4) The expression level of P16 in gastric cancer was negatively correlated with Mcm2 and Ki-67. The expression level of Ki-67 in gastric cancer was positively correlated with Mcm2.Conclusion:(1)There was a high frequency of P16 protein expression loss in gastric cancer, P16 gene may be involoved in carcinogenesis and progression of gastric cancer. (2)Mcm2 and Ki-67 may play an important role in the progression of gastric cancer and be identified as a defining diagnostic marker,both of them are worth of analyzing malignancy grade and judging the prognosis of gastric cancer.