406903

MIR10B

microRNA 10b;MIR10B;microRNA 10b

-

2q31.1

ncRNA

MicroRNAs have been implicated in regulating diverse cellular pathways. Although there is emerging evidence that some microRNAs can function as oncogenes or tumour suppressors, the role of microRNAs in mediating cancer metastasis remains unexplored. Here we show, using a combination of mouse and human cells, that microRNA-10b (miR-10b) is highly expressed in metastatic breast cancer cells and positively regulates cell migration and invasion. Overexpression of miR-10b in otherwise non-metastatic breast tumours initiates robust invasion and metastasis. expression of miR-10b is induced by the transcription factor Twist, which binds directly to the putative promoter of mir-10b (MIRN10B). The miR-10b induced by Twist proceeds to inhibit translation of the messenger RNA encoding homeobox D10, resulting in increased expression of a well-characterized pro-metastatic gene, RHOC. Significantly, the level of miR-10b expression in primary breast carcinomas correlates with clinical progression. These findings suggest the workings of an undescribed regulatory pathway, in which a pleiotropic transcription factor induces expression of a specific microRNA, which suppresses its direct target and in turn activates another pro-metastatic gene, leading to tumour cell invasion and metastasis.

Metastases, and not the primary tumor from which they originate, are the main reason for mortality from carcinoma. Although the molecular mechanisms behind metastasis are poorly understood, it is clear that epigenetic dysregulation at the level of microRNA expression is a key characteristic of the metastatic process that can be exploited for therapy. Here, we describe an miRNA-targeted therapeutic approach for the prevention and arrest of lymph node metastasis. Therapy relies on the inhibition of the pro-metastatic microRNA-10b. It is delivered to primary and lymph node metastatic tumor cells using an imaging-capable nanodrug that is designed to specifically home to these tissues. Treatment of invasive human breast tumor cells (MDA-MB-231) with the nanodrug in vitro downregulates miR-10b and abolishes the invasion and migration of the tumor cells. After intravenous delivery to mice bearing orthotopic MDA-MB-231-luc-D3H2LN tumors, the nanodrug accumulates in the primary tumor and lymph nodes. When treatment is initiated before metastasis to lymph nodes, metastasis is prevented. Treatment after the formation of lymph node metastases arrests the metastatic process without a concomitant effect on primary tumor growth raising the possibility of a context-dependent variation in miR-10b breast oncogenesis.

BACKGROUND: Recent studies have suggested that microRNA-10b (miR-10b) acts as a promoter of metastasis in breast cancer, although the underlying mechanism remains largely unknown. In this study, we provide the first evidence that E-cadherin (E-cad) is a potential target of miR-10b. MATERIAL/METHOD: By applying gain-of-function and loss-of-function approaches in the metastatic breast cancer cell line MDA-MB-231, we demonstrated that miR-10b is necessary and sufficient to regulate the cellular expression of E-cad and in vitro tumor cell invasion. RESULTS: Comparative expression analysis of miR-10b in benign breast lesions (N=16), primary breast cancers (N=21), and metastatic breast carcinomas (N=23) revealed that miR-10b transcription was uniquely up-regulated in metastatic cancers. The expression level of miR-10b positively correlated with tumor size, pathological grading, clinical staging, lymph node metastasis, Her2-positivity and tumor proliferation, but was negatively associated with estrogen receptor-positivity, progesterone receptor-positivity and E-cad mRNA and protein levels. CONCLUSIONS: These findings indicate the existence of a novel E-cadherin-related mechanism by which miR-10b modulates breast cancer metastasis. In addition, miR-10b may be a useful biomarker of advanced progression and metastasis of breast cancer.

MicroRNAs (miRNAs) are a class of small noncoding RNAs whose expression changes are associated with cancer development and invasion. We hypothesized that miR-10b and miR-373, which are increased in lymphatic metastatic tissues, could be directly assayed in the plasma and used to detect the lymph node status of breast cancer patients. Between November 2009 and January 2012, 35 breast ductal carcinoma patients with lymph node metastasis (N patients), 25 ductal carcinoma patients without lymph node metastasis (N(0) patients), and ten healthy female donors were enrolled in the study. Circulating miR-10b and miR-373 were determined in preoperative plasma samples by reverse transcription quantitative real-time PCR assay. In preliminary tests, the plasma levels of circulating miR-10b and miR-373 were found to be significantly higher in ten breast cancer patients with lymph node metastasis compared to ten N(0) patients and ten normal donors (P < 0.01). On validation analysis, the median value level of miR-10b in the 35 N patients was 4.44-fold (P < 0.01) increased, and miR-373 was 4.38-fold (P < 0.01) increased in comparison to the 25 N(0) patients. MiR-10b was used for differentiation of N patients from N(0) patients; the odds ratio was 2.19, and the value of the area under the receiver-operating curve (AUC) was 0.80, with sensitivity of 71 % and specificity of 72 %. For miR-373, the odds ratio was 2.62, and the AUC was 0.84, with sensitivity of 68 % and specificity of 89 %. A combination of the two circulating miRNAs further enhanced the sensitivity to 72 % and the specificity to 94.3 %. Our data suggest that circulating miRNA-10b and miRNA-373 are potential biomarkers for detecting the lymph node status of breast cancer.

BACKGROUND: Qualitative alterations or abnormal expression of microRNAs (miRNAs) in colon cancer have mainly been demonstrated in primary tumors. Poorly overlapping sets of oncomiRs, tumor suppressor miRNAs and metastamiRs have been linked with distinct stages in the progression of colorectal cancer. To identify changes in both miRNA and gene expression levels among normal colon mucosa, primary tumor and liver metastasis samples, and to classify miRNAs into functional networks, in this work miRNA and gene expression profiles in 158 samples from 46 patients were analysed. RESULTS: Most changes in miRNA and gene expression levels had already manifested in the primary tumors while these levels were almost stably maintained in the subsequent primary tumor-to-metastasis transition. In addition, comparing normal tissue, tumor and metastasis, we did not observe general impairment or any rise in miRNA biogenesis. While only few mRNAs were found to be differentially expressed between primary colorectal carcinoma and liver metastases, miRNA expression profiles can classify primary tumors and metastases well, including differential expression of miR-10b, miR-210 and miR-708. Of 82 miRNAs that were modulated during tumor progression, 22 were involved in EMT. qRT-PCR confirmed the down-regulation of miR-150 and miR-10b in both primary tumor and metastasis compared to normal mucosa and of miR-146a in metastases compared to primary tumor. The upregulation of miR-201 in metastasis compared both with normal and primary tumour was also confirmed. A preliminary survival analysis considering differentially expressed miRNAs suggested a possible link between miR-10b expression in metastasis and patient survival. By integrating miRNA and target gene expression data, we identified a combination of interconnected miRNAs, which are organized into sub-networks, including several regulatory relationships with differentially expressed genes. Key regulatory interactions were validated experimentally. Specific mixed circuits involving miRNAs and transcription factors were identified and deserve further investigation. The suppressor activity of miR-182 on ENTPD5 gene was identified for the first time and confirmed in an independent set of samples. CONCLUSIONS: Using a large dataset of CRC miRNA and gene expression profiles, we describe the interplay of miRNA groups in regulating gene expression, which in turn affects modulated pathways that are important for tumor development.

Recently, microRNAs have emerged as regulators of cancer metastasis through acting on multiple signaling pathways involved in metastasis. In this study, we have analyzed the level of miR-10b and cell motility and invasiveness in several human esophageal squamous cell carcinoma cell lines. Our results reveal a significant correlation of miR-10b level with cell motility and invasiveness. Overexpression of miR-10b in KYSE140 cells increased cell motility and invasiveness, whereas inhibition of miR-10b in EC9706 cells reduced cell invasiveness, although it did not alter cell motility. Additionally, we identified KLF4, a known tumor suppressor gene that has been reported to suppress esophageal cancer cell migration and invasion, as a direct target of miR-10b. Furthermore, overexpression of miR-10b in KYSE140 and KYSE450 cells led to a reduction of endogenous KLF4 protein, whereas silencing of miR-10b in EC9706 cells caused up-regulation of KLF4 protein. Coexpression of miR-10b and KLF4 in KYSE140 cells and coexpression of small interfering RNA for KLF4 mRNA and miR-10b-AS in EC9706 cells partially abrogated the effect of miR-10b on cell migration and invasion. Finally, analyses of the miR-10b level in 40 human esophageal cancer samples and their paired normal adjacent tissues revealed an elevated expression of miR-10b in 95% (38 of 40) of cancer tissues, although no significant correlation of the miR-10b level with clinical metastasis status was observed in these samples.

MicroRNA-10b (miR-10b) was recently reported to be dysregulated in some types of cancer and to play a role in invasion and metastasis. However, effects and potential mechanisms of action of miR-10b in the metastasis of hepatocellular carcinoma (HCC) have not been explored. In this study, we confirmed that miR-10b is highly expressed in metastatic HCC tissues and in metastatic HCC cell lines by qRT-PCR. Moreover, patients with higher miR-10b expression had significantly poorer overall survival, and high miR-10b expression was an independent predictor of poor prognosis. Inhibition of miR-10b reduced cell migration and invasion in MHCC97H cells, whereas over-expression of miR-10b in HepG2 cells increased cell migration and invasion. Bioinformatics and luciferase reporter assays revealed that miR-10b binds the 3'-UTR of CADM1 mRNA and represses its translation. Western blot and qRT-PCR showed that CADM1 is inhibited by miR-10b over-expression. Silencing of CADM1 resulted in substantially increased cell motility and invasion similar to that observed with over-expression of miR-10b in HepG2 cells. These results suggest that miR-10b may positively regulate the invasion and metastasis of HCC through targeting CADM1.

MicroRNA-10b (miR-10b) has been reported to facilitate the metastasis of breast cancer. However, little is known about the role of miR-10b in the metastasis of nasopharyngeal carcinoma (NPC). Here, we show that high levels of miR-10b expression in Epstein-Barr virus (EBV)-positive latent membrane protein-1 (LMP1)-expressing NPC cells, and its expression is down-regulated by silencing LMP1 or Twist. Induction of miR-10b over-expression in LMP1-silent C666-1 cells promoted significant wound healing and transmembrane invasiveness in vitro. More importantly, miR-10b over-expression promoted the metastasis of NPC and accelerated the death of tumor-bearing nude mice. These findings strongly suggest that miR-10b positively regulates the metastasis of NPC.

Minimally invasive follicular thyroid carcinoma (MI-FTC) is characterized by limited capsular and/or vascular invasion with good long-term outcomes. However, some cases of MI-FTC show a poor prognosis because of severe distant metastasis (i.e., metastatic MI-FTC). Nonetheless, no method has been established for predicting the prognosis of MI-FTC. This study was conducted to identify novel prognostic factors for metastatic MI-FTC by the use of microRNA (miRNA). Thirty-four patients with MI-FTC were categorized into two groups: the metastatic group, M(+) (n=12) and the non-metastatic group, M(-) (n=22). In the M(+) group, distant metastasis was recognized after the initial operation established the diagnosis of MI-FTC. In the M(-) group, no distant metastasis was recognized postoperatively for >/= 10 years. Using laser microdissection followed by quantitative real-time PCR and PCR arrays, we performed a comprehensive expression profiling of 667 miRNAs in formalin-fixed, paraffin-embedded samples from the initial MI-FTC operation. Furthermore, we assessed the potential use of miRNAs as novel biomarkers for the metastatic potential of MI-FTC by logistic regression analysis. Comprehensive quantitative analysis of miRNA expression in MI-FTC samples revealed that the miR-221/222 cluster (i.e., miR-221, miR-222 and miR-222*), miR-10b and miR-92a were significantly upregulated in the M(+) group compared with the M(-) group. Interestingly, the expression levels of these miRNAs were also shown to be upregulated in widely invasive FTC (WI-FTC; n=13) that has distant metastasis and worse prognosis, indicating a close similarity in the miRNA expression between metastatic MI-FTC and WI-FTC. Logistic regression analysis revealed that miR-10b made a significant contribution to prognosis (OR 19.759, 95%