Studies On The Expression Of KLF4 In Human Gastric Adenocarcinoma And Its Clinical Significance

Objective: To investigate the expression of KLF4 in human gastric adenocarcinoma and the correlation with clinicopathological parameter of gastric adenocarcinoma . To explore the role of KLF4 gene on the development and progression of gastric adenocarcinoma .Methods: All samples were obtained from surgically resection specimens of 50 patients , which contain primary gastric adenocarcinoma and corresponding non- cancerous gastric mucosa . The expressions of KLF4 and Sp1 protein of samples were detected by immunohistochemistry , the expressions of KLF4 and Sp1 mRNA were detected by reverse transcription-PCR(RT-PCR).Result: The positive expression rate of KLF4 protein in gastric adenocarcinoma was 64%(32/50), strong positive staining was 40%(20/50), whereas the positive expression rate of KLF4 protein in corresponding non-cancerous gastric mucosa was 100%(50/50), strong positive staining was 72%(36/50). Compared with non-cancerous gastric mucosa, the level of KLF4 protein was significantly decreased in gastric adenocarcinoma(P<0.01) . The positive expression rate of Sp1 protein in gastric adenocarcinoma was 60%(30/50), strong positive staining was 28%(14/50), whereas the positive expression rate of Sp1 protein in corresponding non- cancerous gastric mucosa was 30%(15/50), strong positive staining was 0%(0/50). Compared with non-cancerous gastric mucosa, the level of Sp1 protein was significantly increased in gastric adenocarcinoma ( P<0.01 ) . The expression of KLF4 mRNA in gastric adenocarcinoma was significantly lower than that in non-cancerous gastric mucosa(0.565±0.324 vs 1.045±0.249, P<0.01), the expression of Sp1 mRNA in gastric cancer was higher than that in non-cancerous gastric mucosa(1.213±0.238 vs 0.684±0.294, P<0.01). Both KLF4,Sp1 protein and mRNA expression levels was correlated with differentiation , lymph node metastasis and TNM stage(P <0.05), but has no correlation with other clinic parameters as age , gender , histological classification , tumor size and tumor location(P>0.05), and a significantly negative correlation between KLF4 and Sp1 mRNA expression was found(r = -0.652 , P<0.05).Conclusion: Down-regulation of KLF4 and up-regulation of Sp1 was correlated with differentiation , lymph node metastasis and TNM stage . KLF4 and Sp1 gene may be powerful indicators for prediciting the progress of gastric adenocarcinoma .