Identification Of The Molecular Markers To Distinguish Malignant Neoplasia Of Gastroscopically Obtained Gastric Mucosa From Benign Ones

Gastric cancer is a common cancer, the mortality rate remain second in the world. incidence of gastric cancer is high in China with a still high mortality. The 5-year survival rate of gastric cancer depend on its depth of invasion, so early diagnosis of gastric cancer and a radical treatment is the only way to a good prognosis. Gastroscopy combined with pathological examination greatly improved the early diagnosis of gastric cancer, but the misdiagnosis rate of gastric cancer before surgery is still up 10% to 20% because of the restriction of physicians technical proficiency and pathological doctor's judgement. The development of new molecules diagnosis system for the prevention and treatment of gastric cancer is essential. So this search is designed to identify molecular markers by comparing expression profile between pathologic diagnosed malignant and benign gastric mucosa changes.gastric mucosa samples with malignant and benign pathological changes, along with contra-lateral gastric mucosa were gastroscopically obtained in 35 patients, RNA was extracted, amplified and hybridized to Oligo microarray containing 1299 spots prepared by our laboratory. The data obtained were normalized with locally weighted linear regression (LOWESS) Method. The significance of intragroup difference between pathological changes and contra-lateral samples is analyzed by significance analysis of microarray (SAM) and the intergroup difference between malignant and benign pathological changed samples was analyzed by t-TEST(P < 0.01).Real-time PCR was applied as a verification method. 367 genes are up-regulated and 261 genes are down-regulated in malignant sample group, 496 genes are up-regulated and 252 genes are down-regulated in benign sample group. 49 genes have been identified as molecular marker can successfully differentiate maglinant samples from benign ones at a 100% rate.mRNA of 6 genes Randomly picked from the 49 genes were quantified by Real time-PCR method, showing the same tendency with the results of microarray. 85% coincidence between pathologic diagnosis and prediction using the 49 genes were proved in 6 unknowm samples testing . Oligonucleotide gene chips to detect gene expression profiling methods can be used for gastric distinguish between benign and malignant lesions of molecular markers to identify research.In short, the gastric mucosa of malignant lesions and benign lesions is successfully clustered based on our establishment of a genetic composition, we believe our finding will provide a valuable reference for clinical malignant gastric diseases distinction.