miR-181c/d is dysregulated in gastric cancer(GC).We investigated the amplification and expression of miR-181c/d and its predicted target genes in GC.Amplification of miR-181c/d was quantified by genomic real-time PCR in GC and adjacent normal tissues,as well as the levels of mature miR-181c/d was performed by real-time PCR in the same tissues.The potential target genes of miR-181c/d were predicted using bioinformatics software.Expression of one potential target gene,PDCD4,was measured by semiquantitative RT-PCR,real-time PCR,and immunohistochemistry.Next,the relationship between miR181c/d expression and PDCD4 expression was analyzed.Results indicated that the amplification and expression of miR-181c/d were significantly higher in GC than in adjacent normal tissues(primary miR-181c/d,P\0.001;miR-181c,P=0.0344;miR-181d,P=0.0153),and there was a strong correlation between mature miR-181c/d and primary miR-181c/d.Thirty-two target genes were predicted,including PDCD4 which is a known tumor suppressor gene.Expression of PDCD4 was significantly down-regulated in GC as compared to adjacent normal tissues and was inversely correlated with miR-181c/d expression in GC(miR-181c and PDCD4:R=-0.496,P=0.008;miR-181d and PDCD4:R=-0.454,P=0.003).Therefore,miR-181c/d may play a pivotal role in the pathogenesis of GC by downregulating PDCD4 expression.
Yuanming PanRui XingJuan AnJiantao CuiWenmei LiMingzhou GuoYouyong Lu
Aberrant expression of microRNAs(miRNAs)was reported frequently in different human cancers.The major role of miRNA is targeting 30-UTR of coding gene and causing translational repression or mRNA degradation.miR-10b overexpression was reported to promote breast cancer metastasis by up-regulating RHOC expression.But its expression in hepatocellular carcinoma(HCC)remains unclear.Our study indicated that the expression of miR-10b was different in HCC and adjacent tissue samples,and reduced expression of miR-10b in HCC was related tovein invasion.High-level expression of RHOC was also related to vein invasion in HCC.But no correlation was found between miR-10b and RHOC expression.These results suggest that miR-10b and RHOC are independent predictors of HCC invasion and metastasis.
Objective:FHL2 was previously identified to be a novel interacting factor of Id family proteins.The aim of this study was to investigate,the effects of FHL2 on Id1-mediated transcriptional regulation activity and its oncogenic activity in human breast cancer cells.Methods:Cell transfection was performed by Superfect reagent.Id1 stably overexpressed MCF-7 cells was cloned by G418 screening.The protein level of Id1 was detected by western blot analysis.Dual relative luciferase assays were used to measure the effect of E47-mediated transcriptional activity in MCF-7 human breast cancer cells.MTT assay was used to measure cell proliferation.Transwell assay was used to measure the invasive capacity of MCF-7 cancer cells.Results:The basic helix-loop-helix(bHLH) factor E47-mediated transcription activity was markedly repressed by Id1 in MCF-7 cells.This Id1-mediated repression was effectively antagonized by FHL2 transduction.Overexpression of Id1 markedly promoted the proliferation rate and invasive capacity of MCF-7 cells;however,these effects induced by Id1 were significantly suppressed by overexpression of FHL2 in cells.Conclusion:FHL2 can inhibit the proliferation and invasiveness of human breast cancer cells by repressing the functional activity of Id1.These findings provide the basis for further investigating the functional roles of FHL2-Id1 signaling in the carcinogenesis and development of human breast cancer.
Wei-dong HanZhi-qiang WuYa-li ZhaoYi-ling SiMing-zhou GuoXiao-bing Fu
Epigenetic changes frequently occur in human colorectal cancer.Genomic global hypomethylation,gene promoter region hypermethylation,histone modifications,and alteration of miRNA patterns are major epigenetic changes in colorectal cancer.Loss of imprinting(LOI) is associated with colorectal neoplasia.Folate deficiency may cause colorectal carcinogenesis by inducing gene-specific hypermethylation and genomic global hypomethylation.HDAC inhibitors and demethylating agents have been approved by the FDA for myelodysplastic syndrome and leukemia treatment.Non-coding RNA is regarded as another kind of epigenetic marker in colorectal cancer.This review is mainly focused on DNA methylation,histone modification,and microRNA changes in colorectal cancer.
