AIM:To clone genes that may predispose us to humangastric cancer and to analyze it’s expression in gastric tissues.METHODS:Specimens of paired tumor,paratumor andnormal gastric mucosa tissues collected from fifteen patientswho suffered from stomach antrum adenocarcinoma wereused for analysis.Seven out of the fifteen cases were firststudied by fluorescent differential display reversetranscription polymerase chain reaction(DDTR-PCR)analysis.The differentially expressed bands of interest were cloned,analyzed by Northern blot,sequencing and RT-PCR.ThroughBLAST,the sequencing results were compared with GenBankdatabase for homology analysis.In situ hybridization withDIG-labeled cRNA probes was used to analyze the expressionof interesting cDNA bands in paraffin embedded pairednormal gastric mucosa and cancer tissues isolated from 30gastric adenocarcinoma patients.RESULTS:DDRT-PCR showed that one of the interestingcDNA bands,which was named W2,expressed much higherin all seven tested tumor and paratumor samples than intheir normal counterparts,it was sub-cloned into a pGEM-TEasy vector.Two subclones were subsequently obtained.One of the subclone,GCRG224,was studied further.Thesequencing result showed that GCRG224 consisted of 1 159base pairs and had one open reading frame(ORF).It locatedat human chromosome 11q14.No homologue was found inGenBank database with GCRG224-ORF.This nucleotidesequence data were submitted to GenBank with accessionNo.AF438406.RT-PCR showed that GCRG224 expressedhigher in 11/15 gastric cancer tissues than in non-tumortissues.However,the result of Northern blot analysis showeda higher GCRG224 expression in the non-tumor tissue thanin the tumor one.Human multiple tissue Northern blot analysisrevealed that GCRG224 also expressed in human normal colontissue,and peripheral blood leukocyte.In situ hybridizationanalysis showed that only 5/30 adenocarcinoma,3/18dysplasia and 6/18 intestinal metaplasia showed higherGCRG224 expression level than the normal gastric glands.However,GCRG224 was over-expressed predominantly in 26/30 cases of normal mucosal epithelium.CONCLUSION:A novel gene named GCRG224 wasidentified from human gastric mucosal tissue.It overexpressed in almost all gastric mucosal epithelium butonly a small portion of cancer and precancerous leisions.The role of GCRG224 expression in gastric epithelium needsfurther study. AIM: To clone genes that may predispose us to humangastric cancer and to analyze it’s expression in gastric tissues. METHODS: Specimens of paired tumor, paratumor and normal gastric mucosa tissues collected from fifteen patients who suffered from stomach antrum adenocarcinoma wereused for analysis. Seven out of the fifteen cases were first blocked by fluorescent differential display reversetranscription polymerase chain reaction (DDTR-PCR) analysis. differentially expressed bands of interest were cloned, analyzed by Northern blot, sequencing and RT-PCR. Through BLAST, the sequencing results were compared with GenBank database for homology analysis.In situ hybridization with DIG-labeled cRNA probes was used to analyze the expression of interesting cDNA bands in paraffin embedded paired normal gastric mucosa and cancer tissues isolated from 30 gastric adenocarcinoma patients. RESULTS: DDRT-PCR showed that one of the interesting cDNA bands, which was named W2, expressed much higher in all seven tested tumor and paratumor samples than intheir normal counterparts, it was sub-cloned into a pGEM-TEasy vector.Two subclones were made. One of the subclone, GCRG224, was studied further. The sequencing result showed that GCRG224 consisted of 1 159base pairs and had one open reading frame (ORF). It located at human chromosome 11q14.No homologue was found in GenBank database with GCRG224-ORF. this nucleotide sequence were submitted to GenBank with accession No. AF438406.RT-PCR showed that GCRG224 expressed higher in 11/15 gastric cancer tissues than in non-tumortissues. Yet, the result of Northern blot analysis showed higher GCRG224 expression in the non-tumor tissue than in the tumor one. Human multiple tissue Northern blot analysis that was GCRG224 also expressed in human normal colontissue, and peripheral blood leukocyte. In situ hybridizationanalysis showed that only 5/30 adenocarcinoma, 3 / 18dysplasia and 6/18 intestinal metaplasia showed higherGCRG224 expression level than the normal gasTric glands. However, GCRG224 was over-expressed predominantly in 26/30 cases of normal mucosal epithelium. CONCLUSION: A novel gene named GCRG224 wasidentified from human gastric mucosal tissue. It overexpressed in almost all gastric mucosal epithelium butonly a small portion of cancer and precancerous leisions. The role of GCRG224 expression in gastric epithelium needsfurther study.