Tumor suppressive microRNAs miR-34a/c control cancer cell expression of ULBP2, a stress-induced ligand of the natural killer cell receptor NKG2D

Malignant cells express ligands for the natural killer cell immunoreceptor NKG2D, which sensitizes to early recognition and elimination by cytotoxic lymphocytes and provides an innate barrier against tumor development. However, the mechanisms that control NKG2D ligand (NKG2DL) expression in tumor cells remain unknown. We recently identified the NKG2DL ULBP2 as strong prognostic marker in human malignant melanoma. Here, we provide evidence that the tumor-suppressive microRNAs (miRNA) miR-34a and miR-34c control ULBP2 expression. Reporter gene analyses revealed that both miRNAs directly targeted the 3'-untranslated region of ULBP2 mRNA and that levels of miR-34a inversely correlated with expression of ULBP2 surface molecules. Accordingly, treatment of cancer cells with miRNA inhibitors led to upregulation of ULBP2, whereas miR-34 mimics led to downregulation of ULBP2, diminishing tumor cell recognition by NK cells. Treatment with the small molecule inhibitor Nutlin-3a also decreased ULBP2 levels in a p53-dependent manner, which was due to a p53-mediated increase in cellular miR-34 levels. Taken together, our study shows that tumor-suppressive miR-34a and miR-34c act as ULBP2 repressors. These findings also implicate p53 in ULBP2 regulation, emphasizing the role of the specific NKG2DL in tumor immune surveillance.     

液态活检miR-509-5p/miR-124比值诊断膀胱癌的临床应用

背景与目的:液态活检是一种从血液、尿液等非实体生物组织中取样分析,主要用于恶性肿瘤诊断、监测及判断预后的方法.该研究通过优化尿液miRNA的提取方法,建立标准化的液态活检手段,筛选并验证膀胱癌患者尿液miRNA标志物以阐明其临床应用价值.方法:收集2014年1月—2015年9月膀胱癌患者及健康对照者的尿液,应用miRNA表达谱芯片进行筛选,在78例膀胱癌患者及23例健康对照者的晨尿中进行实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,RTFQ-PCR)验证,分析液态活检的miRNA标志物与膀胱癌临床病理的关系及其诊断价值.结果:通过对6例膀胱癌及6例健康对照者的尿液miRNA表达谱进行分析,筛选出了10个miRNA有差异表达,结合既往文献报道的膀胱癌尿液miRNA标志物,我们挑选了20个miRNA进行RTFQ-PCR验证,发现miR-509-5p/miR-124比值在膀胱癌患者尿液中表达水平较健康对照者高,差异有统计学意义(P<0.0001).尿液miR-509-5p/miR-124比值随着患者肿瘤分期和肿瘤分级的上升而升高(P=0.003).当界值定在0.41时,miR-509-5p/miR-124比值对膀胱癌的诊断灵敏度为73.1%,特异度为82.6%,曲线下面积(area under the curve,AUC)达到0.864,比尿液脱落细胞学的诊断价值高(P=0.0002).结论:该研究优化了尿液miRNA的提取方法,建立了标准化的液态活检尿液miRNA标志物的检测手段,发现miR-509-5p/miR-124比值可能是膀胱癌理想的诊断标志物.     

Roles for microRNAs, miR-93 and miR-130b, and tumor protein 53-induced nuclear protein 1 tumor suppressor in cell growth dysregulation by human T-cell lymphotrophic virus 1

A role for microRNAs (miRNA) in human T-cell leukemia virus 1 (HTLV-1)-mediated cellular transformation has not been described. Here, we profiled miRNA expression in HTLV-1-transformed human T-cell lines and primary peripheral blood mononuclear cells from adult T-cell leukemia patients. Analyses of 11 different profiles revealed six miRNAs that were consistently up-regulated. Two of the up-regulated miRNAs (miR-93 and miR-130b) target the 3' untranslated region (3'UTR) of the mRNA for a tumor suppressor protein, tumor protein 53-induced nuclear protein 1 (TP53INP1). A low expression level of TP53INP1 protein was found in HTLV-1-transformed cells. Additionally, when antagomirs were used to knock down miR-93 and miR-130b in these cells, the expression of TP53INP1 was increased, suggesting that the latter is regulated inside cells by the former. A role for TP53INP1 in regulating cell growth was established by experiments that showed that enhanced TP53INP1 expression increased apoptosis. Collectively, the findings implicate a miR-93/miR-130b-TP53INP1 axis that affects the proliferation and survival of HTLV-1-infected/transformed cells.     

miR-181a/b significantly enhances drug sensitivity in chronic lymphocytic leukemia cells via targeting multiple anti-apoptosis genes

MicroRNAs (miRNAs) have been shown to play critical roles in regulating the progress of leukemia. We performed miRNA expression profile in six Chinese patients with chronic lymphocytic leukemia (CLL), and in peripheral B cells from pooled 30 healthy donors, using a platform containing 866 human miRNAs. The most frequent changes in miRNAs in CLL cells included downregulation of miR-126, miR-572, miR-494, miR-923, miR-638, miR-130a, miR-181a and miR-181b and up-regulation of miR-29a, miR-660, miR-20a, miR-106b, miR-142-5p, miR-101, miR-30b, miR-34a, miR-let-7f, miR-21 and miR-155. Among the miRNAs down-regulated in CLL cells, we showed that miR-181a/b expression levels were significantly lower in poor prognostic subgroups defined by unmutated immunoglobulin heavy chain variable status and p53 aberrations. Furthermore, under-expression of miR-181a and miR-181b was associated with shorter overall survival and treatment-free survival in CLL patients. We further evaluated fludarabine-induced apoptosis after transfection of primary CLL cells from 40 patients with miR-15a, miR-16-1, miR-34a, miR-181a and miR-181b mimics. Transfection of miR-34a, miR-181a and miR-181b mimics into CLL cells from p53 wild-type patients led to significant increase in apoptosis compared with miRNA control. However, enforced expression of these miRNAs had no effect on B-CLL cells from p53-attenuated patients. We further demonstrated that miR-181a and miR-181b inhibiting BCL-2, MCL-1 and X-linked inhibitor of apoptosis protein by direct binding to 3'UTR. Thus, these results suggest that miR-181a/b may play important roles in the pathogenesis of CLL and may provide a possible therapeutic avenue and a sensitive indicator of the activity of the p53 axis in CLL.     

胃癌组织中高表达的miR-504通过TP53INP1调控胃癌细胞BGC-823的生物学行为

目的:探究微小RNA-504(miRNA-504)在胃癌(GC)组织中的表达水平及其对GC细胞生物学行为的调控机制.方法:收集2020年6月至2020年12月期间三亚中心医院外科收治的48例胃癌患者的肿瘤组织及癌旁组织标本,qPCR检测组织中miR-504、肿瘤蛋白53诱导型核蛋白1(tumor protein 53-...     

Testicular germ cell tumour cells release microRNA-containing extracellular vesicles that induce phenotypic and genotypic changes in cells of the tumour microenvironment

Malignant germ-cell-tumours (GCTs) are characterised by microRNA (miRNA/miR-) dysregulation, with universal over-expression of miR-371~373 and miR-302/367 clusters regardless of patient age, tumour site, or subtype (seminoma/yolk-sac-tumour/embryonal carcinoma). These miRNAs are released into the bloodstream, presumed within extracellular-vesicles (EVs) and represent promising biomarkers. Here, we comprehensively examined the role of EVs, and their miRNA cargo, on (fibroblast/endothelial/macrophage) cells representative of the testicular GCT (TGCT) tumour microenvironment (TME). Small RNA next-generation-sequencing was performed on 34 samples, comprising representative malignant GCT cell lines/EVs and controls (testis fibroblast [Hs1.Tes] cell-line/EVs and testis/ovary samples). TME cells received TGCT co-culture, TGCT-derived EVs, and a miRNA overexpression system (miR-371a-OE) to assess functional relevance. TGCT cells secreted EVs into culture media. MiR-371~373 and miR-302/367 cluster miRNAs were overexpressed in all TGCT cells/subtypes compared with control cells and were highly abundant in TGCT-derived EVs, with miR-371a-3p/miR-371a-5p the most abundant. TGCT co-culture resulted in increased levels of miRNAs from the miR-371~373 and miR-302/367 clusters in TME (fibroblast) cells. Next, fluorescent labelling demonstrated TGCT-derived EVs were internalised by all TME (fibroblast/endothelial/macrophage) cells. TME (fibroblast/endothelial) cell treatment with EVs derived from different TGCT subtypes resulted in increased miR-371~373 and miR-302/367 miRNA levels, and other generic (eg, miR-205-5p/miR-148-3p) and subtype-specific (seminoma, eg, miR-203a-3p; yolk-sac-tumour, eg, miR-375-3p) miRNAs. MiR-371a-OE in TME cells resulted in increased collagen contraction (fibroblasts) and angiogenesis (endothelial cells), via direct mRNA downregulation and alteration of relevant pathways. TGCT cells communicate with nontumour stromal TME cells through release of EVs enriched in oncogenic miRNAs, potentially contributing to tumour progression.     

MicroRNA-34b functions as a potential tumor suppressor in endometrial serous adenocarcinoma

Endometrial serous adenocarcinoma (ESC) is aggressive and carries a poor prognosis. p53 is frequently mutated in ESC. microRNAs (miRNAs) are a direct p53 target and have been implicated in cancer cell behavior. In this study, we compared miRNA expression levels in ESC with the levels in endometrial endometrioid adenocarcinoma (EEC) and normal endometria. Six miRNAs were identified as having aberrant down-regulation specific to ESC with miR-34b being most pronounced. miR-34b was found to have promoter hypermethylation, which when reversed, restored miR-34b expression in the cell lines treated with 5-aza-2' deoxycytidine (DAC). Ectopic expression of miR-34b in turn inhibited cell growth, migration and most notably invasion. Our findings suggest a relationship among p53 mutation, miR-34b promoter methylation and tumor cell behavior. These effects are likely mediated by the downstream target of miR-34b, the proto-oncogene mesenchymal-epithelial transition factor (MET), a known prognostic factor in endometrial carcinomas. The expression of MET was reduced following the restoration of miR-34b in cell lines. In summary, our data suggest that miR-34b plays a role in the molecular pathogenesis of endometrial cancer.     

MicroRNAs miR-371-3 in serum as diagnostic tools in the management of testicular germ cell tumours

Background:

miRNAs are small noncoding RNA molecules that can be released into body fluids. Germ cell tumours (GCTs) overexpress miRNAs of the miR-371-3 cluster. Thus, serum levels of these miRNAs may correlate with tumour load.

Methods:

miRNAs of the miR-371-3 cluster were quantified in cubital vein blood samples of 20 GCT patients with clinical stage 1, and of 4 patients with advanced stages before and after treatment. In six patients testicular vein blood (TVB) was examined additionally. Seventeen healthy males served as controls. Likewise, expression of miRNAs in 15 matching tumour specimens was measured.

Results:

In all patients, serum levels of miRNAs 371-3 were much higher than in controls. In stage 1, levels decreased postoperatively 336.7-fold, 7.4-fold, and 7.7-fold for miRNAs 371a-3p, 372, and 373-3p, respectively (P<0.01). Also, in those cases with advanced disease levels dropped to the normal range after completion of treatment. miR-371-3 levels in TVB exceeded those in peripheral blood in all cases. Expression of miR-371a-3p was also documented in tumour tissue. However, no correlation was found regarding the extent of miRNA expression in tissue and the values measured in matching serum.

Conclusion:

Thus, miR-371a-3p serum level appears to be a useful biomarker in GCTs.     

血清微小RNA(miR-129-3p、miR-767-3p和miR-877)在结直肠癌诊断中的价值

目的:探讨血清微小RNA (microRNA,mi RNA)在结直肠癌诊断中的价值.方法:通过miRNA表达谱芯片检测7例结直肠癌患者血清和10例健康志愿者血清中差异表达的miRNA.应用实时荧光定量PCR法在40例结直肠癌患者血清和18例健康志愿者血清中验证芯片结果,并分析血清特异性miRNA在结直肠癌诊断中的价值.结果:筛选获得10个在结直肠癌中特异性表达的血清miRNA,实时荧光定量PCR验证后获得一组结直肠癌特异性血清miRNA(miR-129-3p、miR-767-3p及miR-877*)生物标志物,这组生物标志物组合检测结直肠癌的灵敏度为77.78％、特异度为100％,并可产生最大受试者工作特征曲线(receiver operator characteristic curve,ROC)的曲线下面积(area under the curve,AUC)为0.914.结论:miR-129-3p、miR-767-3p和miR-877*生物标志物组合有望成为结直肠癌筛查和早期诊断的指标.     

miR-145 inhibits tumor growth and metastasis by targeting metadherin in high-grade serous ovarian carcinoma

High-grade serous ovarian carcinoma (HGSOC), the most common and aggressive subtype of epithelial ovarian cancer, is characterized by TP53 mutations and genetic instability. Using miRNA profiling analysis, we found that miR-145, a p53 regulated miRNA, was frequently down-regulated in HGSOC. miR-145 down-regulation was further validated in a large cohort of HGSOCs by qPCR. Overexpression of miR-145 in ovarian cancer cells significantly suppressed proliferation, migration and invasion in vitro and inhibited tumor growth and metastasis in vivo. Metadherin (MTDH) was subsequently identified as a direct target of miR-145, and was found to be significantly up-regulated in HGSOC. Furthermore, overexpression of MTDH rescued the inhibitory effects of miR-145 in ovarian cancer cells. Finally, we found that high level of MTDH expression correlated with poor prognosis of HGSOC. Therefore, lack of suppression of MTDH by miR-145 when p53 is dysfunctional leads to increased tumor growth and metastasis of HGSOC. Our study established a new link between p53, miR-145 and MTDH in the regulation of tumor growth and metastasis in HGSOC.