Differential gene expression profiling of gastric intraepithelial neoplasia and early-stage adenocarcinoma

• Published in: World journal of gastroenterology : WJG 2014-12, Vol.20 (47), p.17883-17893
• Main Authors: Xu, Xue, Feng, Lin, Liu, Yu, Zhou, Wei-Xun, Ma, Ying-Cai, Fei, Gui-Jun, An, Ning, Li, Yuan, Wu, Xi, Yao, Fang, Cheng, Shu-Jun, Lu, Xing-Hua
• Format: Article
• Language: English
• Subjects: adenocarcinoma; Adenocarcinoma - chemistry; Adenocarcinoma - metabolism; Adenocarcinoma - pathology; Adult; Aged; Biomarkers, Tumor - analysis; Biomarkers, Tumor - genetics; Biopsy; Carcinoma in Situ - chemistry; Carcinoma in Situ - genetics; Carcinoma in Situ - pathology; Cell Cycle Proteins - analysis; Cell Cycle Proteins - genetics; Computational Biology; Databases, Genetic; Diagnosis, Differential; early-stage; Female; Gastric; Gene Expression Profiling - methods; Gene Expression Regulation, Neoplastic; Genetic Predisposition to Disease; Highand; Humans; Immunohistochemistry; low-gra; Male; Middle Aged; Neoplasm Grading; Neoplasm Staging; Oligonucleotide Array Sequence Analysis; Original; Phenotype; Predictive Value of Tests; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Reverse Transcriptase Polymerase Chain Reaction; Stomach Neoplasms - chemistry; Stomach Neoplasms - genetics; Stomach Neoplasms - pathology; Transcription, Genetic
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.v20.i47.17883

AIM:To investigate the differentiated whole genome expression profiling of gastric high-and low-grade intraepithelial neoplasia and early-stage adenocarcinoma.METHODS:Gastric specimens from an upper magnifying chromoendoscopic targeted biopsy were collected from March 2010 to May 2013.Whole genome expression profiling was performed on 19 low-grade intraepithelial neoplasia(LGIN),20 high-grade intraepithelial neoplasia(HGIN),19 early-stage adenocarcinoma(EGC),and 19 chronic gastritis tissue samples using Agilent 4×44K Whole Human Genome microarrays.Differentially expressed genes between different types of lesions were identified using an unpaired t-test and corrected with the Benjamini and Hochberg false discovery rate algorithm.A gene ontology(GO)enrichment analysis was performed using the Gene Spring software GX 12.6.The differentially expressed gene was verified using a real-time TaqManPCR assay with independent tissue samples,including 26 LGIN,15 HGIN,14 EGC,and 20 chronic gastritis.The expression of G0S2 were further validated by immunohistochemical staining(IHC)in 24 LGIN,40 HGIN,30 EGC and 61 chronic gastritis specimens.RESULTS:The gene expression patterns of LGIN and HGIN tissues were distinct.There were 2521 significantly differentially expressed transcripts in HGIN,with951 upregulated and 1570 downregulated.A GO enrichment analysis demonstrated that the most striking overexpressed transcripts in HGIN compared with LGIN were in the category of metabolism,defense response,and nuclear factorκB(NF-κB)cascade.While the vast majority of transcripts had barely altered expression in HGIN and EGC tissues,only 38 transcripts were upregulated in EGC.A GO enrichment analysis revealed that the alterations of the immune response were most prominent in the progression from HGIN to EGC.It is worth noting that,compared with LGIN,289 transcriptswere expressed at higher levels both in HGIN and EGC.A characteristic gene,G0/G1 switch 2(G0S2)was one of the 289 transcripts and related to metabolism,the immune response,and the NF-κB cascade,and its expression was validated in independent samples through real-time TaqManPCR and immunohistochemical staining.In real-time PCR analysis,the expression of G0S2 was elevated both in HGIN and EGC compared with that in LGIN(P<0.01 and P<0.001,respectively).In IHC analysis,G0S2 immunoreactivity was detected in the cytoplasmic of neoplastic cells,but was undetectable in chronic gastritis cells.The G0S2 expression in HGIN was