MicroRNA (miRNA) opens up a new field for molecular diagnosis of cancer. However, the role of circulating miRNAs in plasma/ serum in cancer diagnosis is not clear. The aim of this study was to investigate whether plasma miRNAs can be used as biomarkers for the early detection of colorectal carcinoma (CRC). We measured the levels of 12 miRNAs (miR-134, 2146a, 217-3p, 2181d, 2191, 2221, 2222, 2223, 225, 229a, 2320a and 292a) in plasma samples from patients with advanced colorectal neoplasia (carcinomas and advanced adenomas) and healthy controls using real-time RT-PCR. We found that plasma miR-29a and miR-92a have significant diagnostic value for advanced neoplasia. MiR-29a yielded an AUC (the areas under the ROC curve) of 0.844 and miR-92a yielded an AUC of 0.838 in discriminating CRC from controls. More importantly, these 2 miRNAs also could discriminate advanced adenomas from controls and yielded an AUC of 0.769 for miR-29a and 0.749 for miR-92a. Combined ROC analyses using these 2 miRNAs revealed an elevated AUC of 0.883 with 83.0% sensitivity and 84.7% specificity in discriminating CRC, and AUC of 0.773 with 73.0% sensitivity and 79.7% specificity in discriminating advanced adenomas. Collectively, these data suggest that plasma miR-29a and miR-92a have strong potential as novel noninvasive biomarkers for early detection of CRC.Colorectal carcinoma (CRC) is one of the leading causes of cancer-related death worldwide.1 The CRC incidence and mortality in China increase rapidly in the past several decades.2 Detection of early-stage cancer and precancerous lesions appears to be a key measure to reduce its mortality, and most CRC-related deaths can be preventable through early detection and removal of early-stage cancer and precancerous lesions. The advanced adenoma (a size of at least 10 mm or histologically having high grade dysplasia or significant villous components) is associated with a high risk of progression to an invasive lesion, and represents the optimal target lesion for strategies to prevent CRC.3 Thus, most CRC screening studies evaluate the detection rate of invasive CRC and advanced adenomas.3,4 Several CRC screening tests, including fecal occult-blood testing (FOBT), colonoscopy, and stool DNA test, have been available for years.4,5 However, none of these methods has been established as a wellaccepted screening tool, because of their low adherence rates, high cost or low sensitivity. An ideal screening method should have a high sensitivity and specificity for early-stage cancers and precancerous lesions; it should be also safe and affordable so that it can be broadly accepted by patients.MicroRNAs (miRNAs) are $22 nucleotide noncoding RNA molecules that regulate a variety of cellular processes including cell differentiation, cell cycle progression and apoptosis. MiRNAs have been demonstrated to play an important role in the multistep processes of carcinogenesis either by oncogenic or tumor suppressor function. Study of miRNA has been extended into many kinds of tumors, including CRC. 6,7 Those st...

Purpose: miR-204-5p was found to be downregulated in colorectal cancer tissues in our preliminary microarray analyses. However, the function of miR-204-5p in colorectal cancer remains unknown. We therefore investigated the role, mechanism, and clinical significance of miR-204-5p in colorectal cancer development and progression.Experimental Design: We measured the expression of miR-204-5p and determined its correlation with patient prognoses. Ectopic expression in colorectal cancer cells, xenografts, and pulmonary metastasis models was used to evaluate the effects of miR-204-5p on proliferation, migration, and chemotherapy sensitivity. Luciferase assay and Western blotting were performed to validate the potential targets of miR-204-5p after the preliminary screening by a microarray analysis and computer-aided algorithms.Results: miR-204-5p is frequently downregulated in colorectal cancer tissues, and survival analysis showed that the downregulation of miR-204-5p in colorectal cancer was associated with poor prognoses. Ectopic miR-204-5p expression repressed colorectal cancer cell growth both in vitro and in vivo. Moreover, restoring miR-204-5p expression inhibited colorectal cancer migration and invasion and promoted tumor sensitivity to chemotherapy. Mechanistic investigations revealed that RAB22A, a member of the RAS oncogene family, is a direct functional target of miR-204-5p in colorectal cancer. Furthermore, RAB22A protein levels in colorectal cancer tissues were frequently increased and negatively associated with miR-204-5p levels and survival time.Conclusions: Our results demonstrate for the first time that miR-204-5p acts as a tumor suppressor in colorectal cancer through inhibiting RAB22A and reveal RAB22A to be a new oncogene and prognostic factor for colorectal cancer.

BackgroundThe long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) has been reported to be overexpressed in colorectal cancer (CRC). However, its underlying mechanisms in the progression of CRC have not been well studied.MethodsTo investigate the clinical significance of NEAT1, we analyzed its expression levels in a publicly available dataset and in 71 CRC samples from Fudan University Shanghai Cancer Center. Functional assays, including the CCK8, EdU, colony formation, wound healing, and Transwell assays, were used to determine the oncogenic role of NEAT1 in human CRC progression. Furthermore, RNA pull-down, mass spectrometry, RNA immunoprecipitation, and Dual-Luciferase Reporter Assays were used to determine the mechanism of NEAT1 in CRC progression. Animal experiments were used to determine the role of NEAT1 in CRC tumorigenicity and metastasis in vivo.ResultsNEAT1 expression was significantly upregulated in CRC tissues compared with its expression in normal tissues. Altered NEAT1 expression led to marked changes in proliferation, migration, and invasion of CRC cells both in vitro and in vivo. Mechanistically, we found that NEAT1 directly bound to the DDX5 protein, regulated its stability, and sequentially activated Wnt signaling. Our study showed that NEAT1 indirectly activated the Wnt/β-catenin signaling pathway via DDX5 and fulfilled its oncogenic functions in a DDX5-mediated manner. Clinically, concomitant NEAT1 and DDX5 protein levels negatively correlated with the overall survival and disease-free survival of CRC patients.ConclusionsOur findings indicated that NEAT1 activated Wnt signaling to promote colorectal cancer progression and metastasis. The NEAT1/DDX5/Wnt/β-catenin axis could be a potential therapeutic target of pharmacological strategies.Electronic supplementary materialThe online version of this article (10.1186/s13045-018-0656-7) contains supplementary material, which is available to authorized users.

BackgroundColorectal cancer (CRC) is a major cause of death worldwide. Sensitive, non-invasive diagnostic screen methods are urgently needed to improve its survival rates. Stable circulating microRNA offers unique opportunities for the early diagnosis of several diseases, including cancers. Our aim has been to find new plasma miRNAs that can be used as biomarkers for the detection of CRC.Methodology/Principal FindingsAccording to the results of miRNA profiling performed on pooling plasma samples form 10 CRC patients or 10 healthy controls, a panel of miRNAs (hsa-miR-10a, -19a, -22*, -24, -92a, 125a-5p, -141, -150, -188-3p, -192, -210, -221, -224*, -376a, -425*, -495, -572, -601, -720, -760 and hsa-let-7a, -7e) were deregulated in CRC plasma with fold changes >5. After large scale validation by qRT-PCR performed on another 191 independent individuals (90 CRC, 43 advanced adenoma and 58 healthy participants), we found that the levels of plasma miR-601 and miR-760 were significantly decreased in colorectal neoplasia (carcinomas and advanced adenomas) compared with healthy controls. ROC curve analysis showed that plasma miR-601 and miR-760 were of significant diagnostic value for advanced neoplasia. These two miRNAs together yield an AUC of 0.792 with 83.3% sensitivity and 69.1% specificity for separating CRC from normal controls, and yield an AUC of 0.683 with 72.1% sensitivity and 62.1% specificity in discriminating advanced adenomas from normal controls.Conclusions/SignificancePlasma miR-601 and miR-760 can potentially serve as promising non-invasive biomarkers for the early detection of CRC.

MicroRNAs (miRNAs) are strongly implicated in cancer but their specific roles and functions in the major cancers have yet to be fully elucidated. In this study, we defined the oncogenic significance and function of miR-95, which we found to be elevated in colorectal cancer (CRC) tissues by microarray analysis. Evaluation of an expanded CRC cohort revealed that miR-95 expression was up-regulated in nearly half of the tumors examined (42/87) compared with the corresponding noncancerous tissues. Ectopic overexpression of miR-95 in human CRC cell lines promoted cell growth in vitro and tumorigenicity in vivo, whereas RNAi-mediated silencing of miR-95 decreased cell growth ratio. Mechanistic studies revealed that miR-95 repressed the expression of reporter gene coupled to the 3 0 -untranslated region of sorting nexin 1 (SNX1), whereas miR-95 silencing up-regulated SNX1 expression. Moreover, miR-95 expression levels correlated inversely with SNX1 protein levels in human CRC tissues. RNAi-mediated knockdown of SNX1 phenocopied the proliferation-promoting effect of miR-95, whereas overexpression of SNX1 blocked miR-95-induced proliferation of CRC cells. Taken together, these results demonstrated that miR-95 increases proliferation by directly targeting SNX1, defining miR-95 as a new oncogenic miRNA in CRC. Cancer Res; 71(7); 2582-9. Ó2011 AACR.

Background: Long noncoding RNA (lncRNA) and mRNAs are long RNAs (!200 nucleotides) compared with miRNAs. In blood, long RNAs may be protected by serum extracellular vesicles, such as apoptotic bodies (AB), microvesicles (MV), and exosomes (EXO). They are potential biomarkers for identifying cancer.Methods: Sera from 76 preoperative colorectal cancer patients, 76 age-and sex-matched healthy subjects, and 20 colorectal adenoma patients without colorectal cancer were collected. We investigated the distribution of long RNAs into the three vesicles. Seventy-nine cancer-related long RNAs were chosen and detected using qPCR.Results: The quantity of long RNA has varying distribution among three subtypes of extracellular vesicles in serum. Most mRNA and lncRNA genes had higher quantity in EXOs than that

The expression of miR-638 was found downregulated in colorectal carcinoma (CRC) in our previous study. However, the role of miR-638 in CRC remains unknown. The aim of this study was to determine the function and mechanism of miR-638 in CRC. Here, we verified that miR-638 was frequently downregulated in CRC tissues compared with corresponding noncancerous tissues (NCTs) in an expanded CRC cohort, and survival analysis showed that the downregulation of miR-638 in CRC was associated with poor prognoses. The ectopic expression of miR-638 inhibited CRC cell proliferation, invasion and arrest the cell cycle in G1 phase, whereas the repression of miR-638 significantly promoted CRC cell growth, invasion and cell cycle G1/S transition. Subsequent mechanism analyses revealed that miR-638 inhibited CRC cell growth, invasion and cell cycle progression by targeting TSPAN1. TSPAN1 protein levels were upregulated in CRC samples and were inversely correlated with miR-638 levels. More importantly, high TSPAN1 expression levels in CRC tissues predicted poor overall survival, and appears to be an independent prognostic factor for CRC survival. Furthermore, CpG island methylation analyses revealed that the miR-638 promoter was hypermethylated in CRC and that attenuating promoter methylation was sufficient to restore miR-638 expression in CRC cells. Taken together, our current data demonstrate that miR-638 functions as a tumor suppressor in human CRC by inhibiting TSPAN1, and that TSPAN1 is a potential prognostic factor for CRC.

Purpose: MicroRNAs (miRNA) that are strongly implicated in carcinogenesis have recently reshaped our understanding of the role of non-protein-coding RNAs. Here, we focused on the function and molecular mechanism of miR-202-3p and its potential clinical application in colorectal cancer.Experimental Design: miR-202-3p expression was determined by quantitative reverse transcriptase PCR (qRT-PCR) in 94 colorectal cancer tissues and corresponding noncancerous tissues (NCT). Cell proliferation and colony formation assays in vitro and xenograft experiments in vivo were used to evaluate the effect of miR-202-3p on colorectal cancer cell proliferation. Luciferase assay and Western blot analysis were performed to validate the potential targets of miR-202-3p after the preliminary screening by online prediction and microarray analysis. The mRNA and protein levels of target genes were detected by qRT-PCR and immunohistochemical staining. The copy number of pre-miR-202 was measured by quantitative PCR.Results: First, miR-202-3p was significantly downregulated in 46.7% colorectal cancer samples compared with NCTs. The overexpression of miR-202-3p inhibited colorectal cancer cell growth in vitro and repressed tumorigenesis in nude mice. Then, miR-202-3p downregulated ADP-ribosylation factor-like 5A (ARL5A) protein level by binding to its 3 0 untranslated region, and knockdown of ARL5A phenocopied the proliferation inhibition effect of miR-202-3p. Furthermore, both of ARL5A mRNA and protein levels were upregulated in colorectal cancer samples compared with NCTs and high ARL5A protein levels predicted a poor prognosis. Conclusions: miR-202-3p might function as a tumor suppressor in colorectal cancer, and ARL5A, the functional target of miR-202-3p in colorectal cancer, is a potential prognostic factor for colorectal cancer. Clin Cancer Res; 20(5); 1146-57. Ó2013 AACR.