Mouse mammary tumor virus (MMTV) sequences have been reported to be present in some human breast cancers, but it is unclear whether they have any causal role. In mice, MMTV promotes tumor formation indirectly by insertional mutagenesis of Wnt oncogenes that lead to their activation. In this study, we investigated the status of Wnt-1 in human breast cancers harboring MMTV-like sequences encoding viral envelope (env) genes. We confirmed the detection of env sequences in the nucleus of human breast cancer specimens that are similar in appearance to mouse mammary tumors expressing MMTV env sequences. MMTV env sequences in human breast cancers were also nearly indistinguishable from env sequences in mouse MMTV isolates. Further, Wnt-1 expression was higher in specimens of env-positive ductal carcinoma in situ and invasive ductal carcinoma, relative to env-negative specimens. Our findings extend the evidence that MMTV sequences found in naturally occurring mouse mammary tumors can be found in some human breast cancers, prompting further evaluation of causal roles in these settings. Cancer Res; 70(9); 3576-85. ©2010 AACR.
Abstract. At present, a full understanding of the mechanisms by which colorectal cancer (CRC) distant metastases form is still beyond our reach because of the intricate regulation of gene expression. MicroRNAs (miRNAs) are shown to be involved in various human diseases including cancers through negative regulation of target gene expression at the post-transcriptional level. However, there are only a few studies on the roles of miRNA aberrations in liver metastasis of human colorectal cancer. To identify miRNA expression patterns associated with liver metastasis in human colorectal cancer, the miRNA expression profiles of colorectal cancer tissues with liver metastasis and their non-metastatic counterparts were studied using microRNA microarrays and further confirmed by quantitative RT-PCR. We show that 28 miRNAs are differentially expressed in the colorectal carcinomas with liver metastasis compared to the nonmetastatic counterparts. Of these, 4 miRNAs including miR-150 * , miR-125b-2 * , miR-1179 and miR-139-3p were upregulated in colorectal cancers with liver metastasis while the others were down-regulated. The target genes of selected deregulated miRNAs were predicted through bioinformatic techniques with two functional analyses, gene ontology and KEGG analysis, which showed that categories of high enrichment GOs and specific pathways targeted by dysregulated miRNAs were involved in liver metastasis during human colorectum carcinogenesis. Our results indicated that miRNAs are not only involved in carcinogenesis of colorectum, but may also participate in the progression such as with liver metastases in human colorectal cancers.
Crohn disease (CD) is a multifactorial autoimmune disease which is characterized by chronic and recurrent gastrointestinal tract inflammatory disorder. However, the molecular mechanisms of CD remain unclear. Increasing evidences have demonstrated that circular RNAs (circRNAs) participate in the pathogenesis of a variety of disease and were considered as ideal biomarkers in human disease. This study aimed to investigate circRNA expression profiles and detect new biomarkers in inflammatory bowel disease (IBD). Differentially expression of circRNAs between CD and HCs (health controls) were screened by microarray analysis. Peripheral blood mononuclear cells (PBMCs) from 5 CD patients and 5 HCs were included in the microarray analysis. Then, the differences were validated by quantitative polymerase chain reaction (qPCR) following reverse transcription polymerase chain reaction (RT-PCR) in the patients of CD and sex- and age-matched HCs. The most differential expressed circRNA was further validated in ulcerative colitis (UC) patients. Statistical significance between CD, UC, and HCs was analyzed by Student t test for unpaired samples or one-way analysis of variance (ANOVA). Diagnostic value of each circRNA was assessed by receiver operating characteristic (ROC) curve. We identified 155 up-regulated circRNAs and 229 down-regulated ones by microarray analysis in PBMCs from CD patients compared with HCs. Besides, 4 circRNAs (092520, 102610, 004662, and 103124) were significantly up-regulated validated by RT-PCR and qPCR between CD and HCs. ROC curve analysis suggested important values of circRNAs (092520, 102610, 004662, and 103124) in CD diagnosis, with area under the curve (AUC) as 0.66, 0.78, 0.85, and 0.74, respectively. Then, we further identified that the relative expression levels of circRNA_004662 was upregulated significantly in CD patients compared with UC patients. Herein, the upregulation of the 4 circRNAs (092520, 102610, 004662, or 103124) in PBMCs can be served as potential diagnostic biomarkers of CD, and circRNA_004662 might be a novel candidate for differentiating CD from UC. Moreover, a circRNA–microRNA-mRNA network predicted that circRNA_004662 appeared to be correlated with mammalian target of rapamycin (mTOR) pathway.
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