Oncogene database

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.

MicroRNAs are small endogenous noncoding RNAs, which modulate target gene expression by binding with target mRNA sequences in the 3 untranslated region (UTR) with an imperfect complementarity that inhibits the mRNA translation. Many microRNAs have been reported to function as tumor oncogenes or anti-oncogenes. Recently, more and more microRNAs have been reported to contribute to a tumor s invasive potential. Here, we show that microRNA-10b (miR-10b) was over-expressed in glioma samples and directly associated with the glioma s pathological grade and malignancy. We also found that miR-10b induced glioma cell invasion by modulating tumor invasion factors MMP-14 and uPAR expression via the direct target HOXD10. The miR-10b/HOXD10/MMP-14/uPAR signaling pathway might contribute to the invasion of glioma. Accordingly, glioma cells lost their invasive ability when treated with specific antisense oligonucleotides (miR-10b inhibitors), suggesting that miR-10b could be used as a new bio-target to cure glioma.

MicroRNAs play critical roles in tumorigenesis as either oncogenes or tumor suppressors. As a microRNA induced by Twist, miR-10b function as a metastasis driver in different types of cancer, in which the downstream target gene HOXD10 is the main mediator. In gastric tumor species, miR-10b levels were dramatically elevated in lymphoma node metastasis-positive tumor tissues compared with lymphoma node metastasis-free tumor tissues, and were correlated to dowregulation of HOXD10 expression. In gastric cell lines with distinct degrees of differentiation, miR-10b was highly expressed in the cell line with strong metastatic ability. In MNK45 cells, inhibition of miR-10b led to abrogation of cell invasion. While in GES-1 cells, miR-10 overexpression resulted in enhancement of invasiveness through translational inhibition of HOXD10, and constitutive expression of HOXD10 reversed the effects of miR-10b on cell invasion. Furthermore, either knockdown of RhoC or inhibition of AKT activation interfered miR-10-induced invasiveness in GES-1 cells. In summary, these observations suggest that miR-10b can stimulate the upregulation of RhoC and AKT phosphorylation through targeting HOXD10, thus promoting cell invasion in gastric tumors.

The miRNA participates in a variety of biologic processes, and dysregulation of miRNA is associated with malignant transformation. In this study, we determined specific profile of miRNA associated with oral cancer by using miRNA array screening method. There were 23 miRNAs found with considerably differential expressions between six oral cancer cell lines and five lines of normal oral keratinocytes, in which, 10 miRNAs showed the highest significant difference after independent examination by reverse transcription quantitative PCR. Eight molecules were upregulated, miR-10b, miR-196a, miR-196b, miR-582-5p, miR-15b, miR-301, miR-148b, and miR-128a, and two molecules, miR-503 and miR-31, were downregulated. The most upregulated miR-10b was further examined, and its functions were characterized in two oral cancer cell lines. The miR-10b actively promotes cell migration (2.6- to 3.6-fold) and invasion (1.7- to 1.9-fold) but has minimal effect on cell growth or chemo-/radiosensitivity. Furthermore, miR-10b was considerably elevated in the plasma of xenografted tumor mice (20-fold). This upregulation of miR-10b in plasma was further shown in the patients with oral cancer [P < 0.0001, area under curve (AUC) = 0.932] and precancer lesions (P < 0.0001, AUC = 0.967), suggesting that miR-10b possesses a high potential to discriminate the normal subjects. In conclusion, we have identified at least 10 miRNAs significantly associated with oral cancer, including the most elevated miR-10b. The miR-10b actively participates in cancer formation by promoting cell migration and invasion. Our study using clinical samples suggests that plasma miR-10b has high potential as an early detection marker for oral cancer.

MicroRNAs (miRNAs) are small non-coding RNAs that function as negative gene regulators. Alterations in the expression of miRNAs have been implicated in the pathogenesis and development of most human malignancies. Recent data indicate that microRNA-21 and microRNA-10b are significantly elevated in glioblastoma multiforme (GBM) suggesting their role in the regulation of multiple genes associated with cancer. In this study, U87MG human glioblastoma cells were treated with miRNA inhibitors targeting miR-10b and miR-21, alone or in combination. The results showed that the miR-21 inhibitor additively interacted with miR-10b inhibitor on U87MG cells. The 50% inhibitory concentration values were dramatically decreased in cells treated with the combination of miR-10b and miR-21 inhibitors. Furthermore, inhibitors synergistically combined, enhanced apoptosis significantly and reduced invasion ability assessed by flow cytometry and Transwell migration assay. Thus, the miR-21 inhibitor may interrupt the activity of EGFR pathways, increasing PDCD4 and TPM1 expression and reducing MMP activities, independently of PTEN status. Meanwhile, miR-10b inhibitor reduced by Twist proceeds to inhibit translation of the mRNA encoding HOXD10 leading to the increase of the expression of the well-characterized pro-metastatic gene RHOC. Taken together, these data strongly suggest that a combination of miR-21 inhibitor and miR-10b inhibitor could be an effective therapeutic strategy for controlling the growth of GBM by inhibiting oncogene expression and overexpressing tumor suppressor genes. Moreover, a regulatory strategy based on the combination of miRNA inhibitors may provide insights into the mechanisms of the modulation of signaling genes involved in tumor cell apoptosis and invasiveness.