Comprehensive analysis of microRNA expression patterns in hepatocellular carcinoma and non-tumorous tissues

Abstract

MicroRNAs (miRNAs) are a non-coding family of genes involved in post-transcriptional gene regulation. These transcripts are associated with cell proliferation, cell differentiation, cell death and carcinogenesis. We analysed the miRNA expression profiles in 25 pairs of hepatocellular carcinoma (HCC) and adjacent nontumorous tissue (NT) and nine additional chronic hepatitis (CH) specimens using a human miRNA microarray. Targets and references samples were co-hybridized to a microarray containing whole human mature and precursor miRNA sequences. Whereas three miRNAs exhibited higher expression in the HCC samples than that in the NT samples, five miRNAs demonstrated lower expression in the HCC samples than in the NT samples (Po0.0001). Classification of samples as HCC or NT by using support vector machine algorithms based on these data provided an overall prediction accuracy of 97.8% (45/46). In addition, the expression levels of four miRNAs were inversely correlated with the degree of HCC differentiation (Po0.01). A comparison of CH and liver cirrhosis samples revealed significantly different pattern of miRNA expression (Po0.01). There were no differences, however, between hepatitis B-positive and hepatitis C-positive samples. This information may help clarify the molecular mechanisms involved in the progression of liver disease, potentially serving as a diagnostic tool of HCC.

Do microRNA 96, 145 and 221 expressions really aid in the prognosis of prostate carcinoma?

“…2,12 They found five downregulated types of miRNA, including miR-145, and emphasized that the finding of decreased miR-145 expression was consistent with the finding that miR-145 was one of the most frequently downregulated types of miRNA in 16 prostatectomy specimens in the study by Ozen et al 10 Decreased miR-145 expression has been described in lung caner, breast cancer and hepatocellular carcinoma. 17,18 In addition, the expression of miR-145 has consistently been found to be decreased in the adenomatous and cancer stages of colorectal cancer. 19,20 Porkka et al 11 reported that miR-145 was downregulated in PCa compared with BPH.…”

Potentially important microRNA cluster on chromosome 17p13.1 in primary peritoneal carcinoma

“…Of note, dysregulation of miR-16, miR-195 and miR-497 have also been found in a range of other cancers, including chronic lymphocytic leukaemia, prostate, pancreas, cervical carcinomas together with sarcomas and benign uterine leiomyomata (Table 4). 12,[53][54][55][56][57][58][59][60][61][62][63] Little is known about the mechanisms of micro-RNA deregulation in neoplastic tissue. MicroRNA genes are commonly located at minimal regions of amplification, loss of heterozygosity and breakpoint regions, suggesting that abnormal microRNA profiles can be caused by somatic gene mutation.…”

MicroRNA analysis as a potential diagnostic tool for papillary thyroid carcinoma

“…By using array-based technology and reverse transcription (RT)-PCR, the global miRNA expression profiles as well as the level of individual miRNA species have been analyzed in various human cancers, and aberrant miRNA expression was found in all tumor types studied to date, including hematological malignancies, 6 lymphoma, 7 melanoma, 8 glioblastoma, 9,10 as well as epithelial cancers from lung, 11,12 breast, 13,14 colon, 15,16 liver, 17,18 thyroid, [19][20][21][22] pancreas [23][24][25][26] etc. When compared to their normal-tissue counterparts, both overexpression and underexpression of miRNA has been observed, with decreased expression appearing to be more common in some studies, 8,27 leading to the hypothesis that oncogenes might be target genes for these miRNAs.…”