Expression And Significance Of KAI1 Gene In Gastric Carcinomas

Objective: To investigate the expression of KAI1 gene in normal grastric tissues,gastric atypical hyperplasias and gastric carcinomas and compare with the expressionof nm23 and p53 ptotein. Furtherly to understand the relationship between geneexpression of KAI1 and its role in tumorgenesis and development. To find newmolecular marker and taget for diagnosis and treatment of gastric carcinoma.Methods: The expression of KAI1, nm23 and p53 protein in 22 normal grastrictissues, 65 gastric atypical hyperplasias and 74 gastric carcinomas were examined bySP immunohistochemical method. The KAI1 mRNA was examined by in situhybridization(ISH) method.Result:1. The positive expression rates of KAI1, nm23 proteins in normal gastric tissues,gastric atypical hyperplasias and gastric carcinomas were 81.8％,76.9％, 43.2％and86.3％, 80.0％, 40.5％respectively, and were gradually decreased with significantdifference (P＜0.001) among the groups. However, p53 ptotein expression exhibited aincreasing tendency with significant difference (P＜0.001) among the groups and were18％, 18.4％and 70.2％respectively. The expression of KAI1 was positively relatedto that of nm23 protein, but negatively related to that of p53.2.x~2 and Fisher exact test showed that the expressions of KAI1 gene werecorrelated to the malignant progression of gastric carcinoma, lymph nodes metastasisand vessel invassion, but were not correlated with patient's age and gender.3. The positive rates of KAI1 gene mRNA by in situ hybridization (ISH) methodin normal grastric tissues, gastric atypical hyperplasias and gastric carcinomas were92.0％, 83.1％, 40.5％. Spearman degress test showed that there was a positivecorrelation between KAI1 gene mRNA of protein expressions (r=0.967,P=0.001).Conclusions: 1.The positive expression of KAI1 protein in gastric carcinomas were lower than that in nomal gastric tissues, and the positive expression ininfiltrating group were lower than that in non-infiltrating group. KAI1 gene may beone of the useful biomarker for the evaluation of gastric carcinomas invasion abilityand prognosis.2. The positive of KAI1 both mRNA and protein in normal gastric tissues, gastricatypical hyperplasia and gastric carcinomas are gradually decreased. The consistencyexpression of KAI1 both mRNA and protein in different lesions shows that theexpression of KAI1 gene is suppressed in carcinoma tissues and the suppression takeplace at the transcription level or above, and KAI1 gene may be a available taget forgene treatment.