Identification of genes with universally upregulated or downregulated expressions in colorectal cancer

Abstract

Background and Aim Differentially expressed (DE) genes detected at the population‐level through case–control comparison provide no information on the dysregulation frequencies of DE genes in a cancer. In this work, we aimed to identify the genes with universally upregulated or downregulated expressions in colorectal cancer (CRC). Methods We firstly clarified that DE genes in an individual cancer tissue should be the disease‐relevant genes, which are dysregulated in the cancer tissue in comparison with its own previously normal state. Then, we identified DE genes at the individual level for 2233 CRC samples collected from multiple data sources using the RankComp algorithm. Results We found 26 genes that were upregulated or downregulated in almost all the 2233 CRC samples and validated the results using 124 CRC tissues with paired adjacent normal tissues. Especially, we found that two genes (AJUBA and EGFL6), upregulated universally in CRC tissues, were extremely lowly expressed in normal colorectal tissues, which were considered to be oncogenes in CRC oncogenesis and development. Oppositely, we found that one gene (LPAR1), downregulated universally in CRC tissues, was silenced in CRC tissues but highly expressed in normal colorectal tissues, which were considered to be tumor suppressor genes in CRC. Functional evidences revealed that these three genes may induce CRC through deregulating pathways for ribosome biogenesis, cell proliferation, and cell cycle. Conclusions In conclusion, the individual‐level DE genes analysis can help us find genes dysregulated universally in CRC tissues, which may be important diagnostic biomarkers and therapy targets.

The LIM Protein Ajuba Augments Tumor Metastasis in Colon Cancer

“…Ajuba has been found to be significantly upregulated in several cancers such as esophageal squamous cell carcinoma, cervical cancer and colorectal cancer [ 6 , 7 , 8 , 9 ]. In the literature, there are discrepancies as to whether Ajuba is a driver or suppressor of tumor cell proliferation.…”

EGFL6 Promotes Colorectal Cancer Cell Growth and Mobility and the Anti-cancer Property of Anti-EGFL6 Antibody

“…EGFL6 is proved to relate to the progression of several cancers [31][32][33][34]; however, the function and mechanism of EGFL6 in CRC has not yet been elucidated in detail. Recently, a research found EGFL6 increased abundance in human CRC tissues by gene analysis, but were nearly undetected in normal colorectal tissues [35]. EGFL6 also signi cantly express in oral squamous cell carcinoma tumor part but not express in normal part, with signi cantly higher expression in stage IV compare to stage I [31].…”

EGFL6 promotes colorectal cancer cell growth and mobility and the anti-cancer property of anti-EGFL6 antibody

“…EGFL6 is proved to relate to the progression of several cancers [28][29][30][31]; however, the function and mechanism of EGFL6 in CRC has not yet been elucidated in detail. Recently, a research found EGFL6 increased abundance in human CRC tissues by gene analysis, but were nearly undetected in normal colorectal tissues [32]. EGFL6 also signi cantly express in oral squamous cell carcinoma tumor part but not express in normal part, with signi cantly higher expression in stage IV compare to stage I [28].…”