论文部分内容阅读
Background: Colorectal cancer(CRC)is one of the most commonly diagnosed cancers and a major cause of cancer death.However,the molecular mechanisms underlying CRC initiation,growth and metastasis are poorly understood.MicroRNAs(miRNAs)are small(approximately 20~22 nucleotides),noncoding RNAs that regulate gene expression by the inhibition of the translation and/or decreasing of the stability of their mRNA targets.It has been demonstrated that miRNAs play a significant role in tumorigenesis by down-regulating tumor suppressor genes or oncogenes.Method: The miRNA microarrays that we used in this study were deposited in the National Center for Biotechnology Information(NCBI)Gene Expression Omnibus(GEO)database with accession code GSE35602.step 1: Normalization for miRNA expression profile; step 2:Compute the global repression effect of miRNA expression profile on their target genes; step 3:Do differential analysis for target genes based on the repression score; step 4:Do gene function enrichment analysis.Results: In this study,based on our previous work for comprehensively analyzing miRNA sequencing data,we examined a series of colorectal cancer microRNAs expression profiles data.Results show that all these CRC samples share the same four pathways including TGF-beta signaling pathway,which is important in colorectal carcinogenesis.Twenty-one microRNAs that evolved in the four overlapped pathways were then discovered.Further analysis selected miR-21 as an important regulator for CRC through TGF-beta pathways.This study develops methods for discovering tumor specific miRNA cluster as biomarker and for screening new cancer therapy targets based on miRNA sequencing.