Exosomal microRNA in serum is a novel biomarker of recurrence in human colorectal cancer

Background:

Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the early detection of recurrence in human colorectal cancer (CRC).

Methods:

Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT–PCR.

Results:

Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001).

Conclusions:

Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.     

MicroRNA-451 functions as a tumor suppressor in human non-small cell lung cancer by targeting ras-related protein 14 (RAB14)

Accumulating evidence suggests that microRNAs (miRNAs) are important gene regulators, which can have critical roles in diverse biological processes including tumorigenesis. In this study, we analyzed the miRNA expression profiles in non-small cell lung carcinoma (NSCLC) by use of a miRNA microarray platform and identified 40 differentially expressed miRNAs. We showed that miRNA (miR)-451 was the most downregulated in NSCLC tissues. The expression level of miR-451 was found to be significantly correlated with tumor differentiation, pathological stage and lymph-node metastasis. Moreover, low miR-451 expression level was also correlated with shorter overall survival of NSCLC patients (P<0.001). Ectopic miR-451 expression significantly suppressed the in vitro proliferation and colony formation of NSCLC cells and the development of tumors in nude mice by enhancing apoptosis, which might be associated with inactivation of Akt signaling pathway. Interestingly, ectopic miR-451 expression could significantly inhibit RAB14 protein expression and decrease a luciferase-reporter activity containing the RAB14 3'-untranslated region (UTR). In addition,, RNA interference silencing of RAB14 gene could recapitulate the tumor suppressor function of miR-451, whereas restoration of RAB14 expression could partially attenuate the tumor suppressor function of miR-451 in NSCLC cells. Furthermore, we also showed that strong positive immunoreactivity of RAB14 protein was significantly associated with downregulation of miR-451 (P=0.01). These findings suggest that miR-451 regulates survival of NSCLC cells partially through the downregulation of RAB14. Therefore, targeting with the miR-451/RAB14 interaction might serve as a novel therapeutic application to treat NSCLC patients.     

Circulating exosomal miR-125a-5p as a novel biomarker for cervical cancer

Exosomal microRNAs (miRs/miRNAs) have been reported to be associated with cervical cancer. The aim of the present study was to investigate circulating exosomal miRNA as a biomarker for cervical cancer diagnosis. In the present study, samples from 6 patients with cervical cancer and 6 healthy control subjects were retrieved for exosomal RNA-sequencing. The results revealed that a total of 39 miRNAs were differentially expressed between patients with cervical cancer and healthy controls (P<0.001; fold-change >2.0). Exosomal miR-125a-5p was further quantified in plasma from 60 subjects, which included 22 healthy individuals and 38 patients with cervical cancer. miR-16a-5p served as the reference miRNA for quantitative PCR analysis of exosomal miR-125a-5p in patients with cervical cancer and healthy individuals. The results revealed that exosomal miR-125a-5p expression levels in the patients with cervical cancer were significantly lower than those in the healthy controls (P<0.001). Receiver operating characteristic (ROC) curve analyses were performed and the results revealed that the level of plasma exosomal miR-125a-5p was a potential marker for differentiating between non-cervical cancer and cervical cancer, with an ROC area under the curve of 0.7129. At the cut-off value of 2.537 for miR-125a-5p, cervical cancer diagnostic sensitivities and specificities were 59.1 and 84.2%, respectively. The present study provides confirmation that exosomal miR-125a-5p could potentially serve as a biomarker for cervical cancer diagnosis. The present study involved only a small number of clinical samples; more samples are required to support the conclusions of the present study.     

Exosomal microRNA: A Diagnostic Marker for Lung Cancer

BackgroundTo date, there is no screening test for lung cancer shown to affect overall mortality. MicroRNAs (miRNAs) are a class of small noncoding RNA genes found to be abnormally expressed in several types of cancer, suggesting a role in the pathogenesis of human cancer. Their accumulation within the peripheral circulation appears to be unique to cancer. The genome-wide expression profiling of miRNAs has been shown to be significantly different among primary lung cancers and corresponding noncancerous lung tissues. In studies demonstrating diagnostic miRNA signatures of NSCLC, specific miRNAs were overexpressed compared with normal lung tissue (miR-17-3p, miR-21, miR-106a, miR-146, miR-155, miR-191, miR-192, miR-203, miR-205, miR-210, miR-212, and miR-214). In this study, we evaluate the levels of circulating tumor exosomes, the circulating levels of exosomal small RNA, and specific exosomal miRNAs in patients with and without lung adenocarcinoma, correlating the levels with the American Joint Committee on Cancer (AJCC) stage of disease to validate it as an acceptable marker for diagnosis and prognosis in patients with adenocarcinoma of the lung.Patients and MethodsPlasma from patients with lung adenocarcinoma and a control group without known lung cancer or other active cancer were collected. Exosomes were isolated from plasma samples by a 2-step procedure using size-exclusion chromatography and magnetic activated cell sorting (MACS). Plasma samples (1 mL) were separated on Sepharose 2B, monitoring elution at 280 nm, and using a modified MACS procedure, exosomes of tumor origin were isolated using anti—epithelial cell adhesion molecule. Small RNA was isolated from circulating tumor exosomes using mirVana isolation kit (Ambion, Austin, TX) and this low molecular RNA enriched fraction was used for miRNA profiling as defined by microarray analysis. Low molecular weight RNA (5 μg) was used for hybridization on miRNA microarray chips. These miRNA were identified as hsa-miR-17-3p, hsa-miR-21, hsa-miR-106a, hsa-miR-146, hsa-miR-155, miR-191, miR-192, miR-203, miR-205, miR-210, miR212, and hsa-miR-214.ResultsTo date, 28 patients and 9 controls, AJCC stages I-IV, ages 21–80 years, were enrolled in the study. Exosome concentration ranged from 1.02–9.24 mg/mL for the lung adenocarcinoma group versus 0.62–1.7 mg/mL in the control group. The total miRNA concentration ranged from 131.1–275 ug/mL for the lung adenocarcinoma group versus 44.9–131.1 ug/mL in the control group. The mean exosome value in the lung cancer group was 2.85 mg/mL (CI, 1.94–3.76) and 0.77 mg/mL (CI, 0.68–0.86; P < .001). The mean RNA value in the lung cancer group was 158.6 ug/mL (CI, 145.7–171.5) and 68.1 ug/mL (CI, 57.2–78.9; P < .001). The only patient in the control group who had an exosome concentration > 1.0 mg/mL and RNA concentration > 100 ug/mL had a history of vulvar cancer without evidence of active disease. No correlation between the levels and the stage of disease was found. To compare the presence of specific miRNAs between tumors and their corresponding circulating exosomes, miRNA fractions were isolated and profiled from circulating tumor exosomes and the original tumor. MicroRNA profiling was performed in duplicate, using microarrays containing probes for 467 human mature miRNA. Comparisons between peripheral circulation-derived exosomes and tumors indicated that the miRNA signatures were not significantly different. This approach confirmed that the 12 specific miRNA were elevated in NSCLC and that the associations of these 12 were mirrored in the circulating exosomes. The levels of tumor-derived miRNA profiles exhibited a strong correlation with the levels of peripheral blood-derived exosomal miRNAs (for miR-17-3p, r = 0.76; miR-21, r = 0.77; miR-146, r = 0.88; miR-155, r = 0.85; miR-191, r = 0.83; miR-203, r = 0.85; miR-205, r = 0.91; and miR-214, r = 0.71).ConclusionThe significant difference in total exosome and miRNA levels between patients with lung cancer and controls suggests that exosomal miRNA is a screening test for lung adenocarcinoma. There is no obvious correlation between the total exosomal miRNA levels and stage of disease; however, it has been suggested in miRNA profiling studies of tumor tissue, that miRNA expression might be critical for the development of cancer but not for its progression. If specific miRNA levels predict response to treatment and can add prognostic information in addition to conventional staging needs further study. While validation studies will be necessary before bypassing the use with tumor mass biopsies, the use of exosomal miRNA profiling could extend this approach to screening of asymptomatic individuals as well as for monitoring disease recurrence.     

Identification of new aberrantly expressed miRNAs in intestinal-type gastric cancer and its clinical significance

miRNAs are small 19 to 22 nucleotide sequences of RNA that negatively regulate gene expression. miRNA expression profiles may become useful biomarkers for diagnostics, prognosis and prediction of response to treat, and it could be a powerful tool for cancer prevention and therapeutics. Several miRNA expression profiles of miRNAs in gastric cancer have been reported, but these studies screened only few miRNAs and samples used in experiments include several different subtypes of gastric cancers, which decrease the sensitivity to identify new aberrant miRNAs. In this study, a miRNA expression profile was identified by miRCURY LNA Array (v.14.0) between intestinal-type gastric cancers and normal tissues. Forty miRNA precursors were up-regulated and thirty-six miRNA were down-regulated in intestinal-type gastric cancers (p<0.01). Sixteen new miRNAs were found in intestinal-type gastric cancers. Seventeen new miRNAs were found in intestinal-type gastric cancers. miR-145, miR-27a, miR-494 are differently expressed between intestinal-type and diffuse-type gastric cancers. miR-32, miR-182 and miR-143 dysregulated expression levels are related with different pathological stages of intestinal-type gastric cancers (p<0.01). Taken together, aberrantly expressed miRNAs may offer new clues to tumorigenesis of gastric cancers. miR-32, miR-182 and miR-143 may be potential diagnostic biomarkers for intestinal-type gastric cancers.     

结肠癌组织和癌旁组织miRNA表达谱研究

目的探讨结肠癌癌组织和癌旁组织中miRNA的表达差异,寻找潜在的结肠癌特异表达谱。方法miRNA表达芯片检测手术切除未发生转移的原位结肠癌组织和癌旁组织标本中miRNA表达水平,并采用Real-time PCR对差异表达的miRNA进行验证。结果miRNA表达芯片分析发现肿瘤细胞中24种miRNA表达下调,27种表达上调。miR-145、miR-143在癌组织中表达显著下调,miR-451在癌组织中表达显著上调,并被Real-time PCR方法进一步证实。结论结肠癌癌组织和癌旁组织中miRNA的表达存在差异,miR-145、miR-143在结肠癌组织中表达下调,miR-451表达上调,结肠癌组织具有特异miRNA表达谱,可作为结肠癌潜在诊断芯片进行开发。     

人肝细胞肝癌和癌旁正常组织microRNA表达差异的分析

目的比较肝细胞肝癌和癌旁正常组织microRNA的表达差异,为研究肝癌的发病机理提供理论依据。方法用microRNA 微阵列芯片技术研究肝细胞肝癌细胞474种miRNAs表达谱,对比癌旁正常组织筛选差异表达miRNAs。结果获得213个差异表达（P<0.01）的miRNAs分子数据,与配对癌旁正常组织相比,其中上调表达的有116个,如miR-181,miR-21,let-7e等;下调表达的有97个,如miR-199,miR-451,miR-122等。结论miRNA可能成为肝癌的诊断工具,并对研究肝癌的致病机理提供新的理论依据。     

microRNA expression profiling of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is posing a serious health problem worldwide. The association between its pathogenesis and microRNAs (miRNA) has not been elucidated. In this study, miRNA expression profiling was performed to screen the miRNA expression changes in 8 NPC tissues and 4 normal nasopharyngeal tissues. Thirty-four miRNAs were identified to be differentially expressed; of these, one miRNA (miR-18a) was overexpressed and 33 miRNAs (miR-34b, miR-34c, let-7 family, etc.) were underexpressed in NPC tissues compared to the normal samples. Validation was performed by real-time quantitative PCR for two altered miRNAs (miR-34b and let-7g) and one non-differentially expressed miRNA (miR-30c). Unsupervised hierarchical clustering analysis showed that the aberrant miRNAs were correlated with the clinical stage of NPC patients. In addition to several biological pathways that are well characterised in NPC and which were significantly targeted by the underexpressed miRNAs, two novel pathways, nervous system development and sensory perception of sound, were identified to be strongly associated with NPC development. Furthermore, a c-Myc centered miRNA regulatory network was inferred in NPC. Our study reveals that aberrantly expressed miRNAs play important roles in NPC tumorigenesis and may serve as potential targets for novel therapeutic strategies in the future.     

Differential microRNA Expression by Solexa Sequencing in the Sera of Ovarian Cancer Patients

MicroRNAs are a class of small noncoding RNA which play important regulatory roles in a variety of cancers.MiRNA-specific expression profiles have been reported for several pathological conditions. In this study, wecombined large scale parallel Solexa sequencing to identify 11 up-regulated miRNAs and 19 down-regulatedmiRNAs with computational techniques in the sera of ovarian cancer patients while using healthy serum as thecontrol. Among the above, four miRNAs (miR-22, miR-93, miR-106b, miR-451) were validated by quantitativeRT-PCR and found to be significantly aberrantly expressed in the serum of ovarian cancer patients (P<0.05).There were no significant differences between samples from cancer stage Ⅰ/Ⅱ and Ⅲ/Ⅳ. However, the levelsof miR-106b (p=0.003) and miR-451 (p=0.007) were significantly different in those patients under and over 51yearsof age. MiR-451 and miR-93 were also specific when analyzed with reference to different levels of CA125.This study shows that Solexa sequencing provides a promising method for cancer-related miRNA profiling, andselectively expressed miRNAs could be used as potential serum-based biomarkers for ovarian cancer diagnosis.     

MicroRNA signatures in human ovarian cancer

Epithelial ovarian cancer (EOC) is the sixth most common cancer in women worldwide and, despite advances in detection and therapies, it still represents the most lethal gynecologic malignancy in the industrialized countries. Unfortunately, still relatively little is known about the molecular events that lead to the development of this highly aggressive disease. The relatively recent discovery of microRNAs (miRNA), a class of small noncoding RNAs targeting multiple mRNAs and triggering translation repression and/or RNA degradation, has revealed the existence of a new level of gene expression regulation. Multiple studies involving various types of human cancers proved that miRNAs have a causal role in tumorigenesis. Here we show that, in comparison to normal ovary, miRNAs are aberrantly expressed in human ovarian cancer. The overall miRNA expression could clearly separate normal versus cancer tissues. The most significantly overexpressed miRNAs were miR-200a, miR-141, miR-200c, and miR-200b, whereas miR-199a, miR-140, miR-145, and miR-125b1 were among the most down-modulated miRNAs. We could also identify miRNAs whose expression was correlated with specific ovarian cancer biopathologic features, such as histotype, lymphovascular and organ invasion, and involvement of ovarian surface. Moreover, the levels of miR-21, miR-203, and miR-205, up-modulated in ovarian carcinomas compared with normal tissues, were significantly increased after 5-aza-2'-deoxycytidine demethylating treatment of OVCAR3 cells, suggesting that the DNA hypomethylation could be the mechanism responsible for their overexpression. Our results indicate that miRNAs might play a role in the pathogenesis of human EOC and identify altered miRNA gene methylation as a possible epigenetic mechanism involved in their aberrant expression.     

Down Regulated Expression Levels of miR-27b and miR-451a as a Potential Biomarker for Triple Negative Breast Cancer Patients Undergoing TAC Chemotherapy

Background: Triple negative breast cancer (TNBC) is associated with poor prognosis, aggressive phenotype(s) of tumours, partial chemotherapy response, and lack of clinically proven therapies. MicroRNAs (miRNAs) can target and modulate key genes that are involved in TNBC chemotherapy. Deregulated miRNA expression is highly involved in anti-cancer drug resistance phenotype and thus, miRNAs tend to be promising candidates for prediction of chemotherapy response and recurrence. Aim: This study aimed to investigate the expression levels of selected miRNAs (miR-21, miR-27b, miR-34a, miR-182, miR-200c and miR-451a) in cancerous and normal adjacent tissues of TNBC patients and to correlate with the clinicopathological data. Methods: Forty-one (41) FFPE tissue block of histopathologically confirmed TNBC patients was collected. Total RNA from the cancerous and adjacent non-cancerous tissues were isolated, transcribed, and pre-amplified. The relative expression level of miRNAs in tumour and normal adjacent tissues of TNBC patients was analysed using qRT-PCR. Results: Out of six miRNAs studied, the relative expression of miR-27b and miR-451a were found to be significantly lower in cancerous as compared to normal adjacent tissues of TNBC patients. In addition, a significant down regulation of miR-451a was also observed in infiltrating ductal carcinoma subtype, stages I and II, in both grade II and III, premenopausal and postmenopausal as well as in those with positive axillary lymph node metastases. Conclusion: The results suggest the possible utilization of miR-27b and miR-451a expression levels as potential predictive risk markers for TNBC patients undergoing TAC chemotherapy.     

血清外泌体miR-148a联合miR-106a检测用于胃癌筛查的研究探讨

  目的  寻找合适的外泌体miRNA作为肿瘤生物标志物，辅助临床进行胃癌筛查。  方法  将miR-148a及miR-106a作为潜在标志物，研究两种miRNA在癌组织及癌旁组织表达的差异性。选取2017年9月至2018年9月在福建省立医院诊治的初诊胃癌术后标本共37对（胃癌组织及癌旁组织）进行组织学miRNA检测。选取初诊胃癌患者83例为胃癌组，良性病变的患者78例为对照组，全部进行血清外泌体miRNA检测。  结果  与癌旁组织相比，癌组织中miR-148a表达水平降低，miR-106a表达水平升高，联合检测2-△△CP[△CP=CP_{（miR-148a）}-CP_{（miR-106a）}]值降低。与对照组相比，胃癌患者中血清外泌体miR-106a表达水平降低，联合检测2-△△CP值升高。血清外泌体联合检测2-△△CP值对胃癌组和对照组鉴别的曲线下面积[AUC为0.844（95%CI:0.782~0.905，P < 0.001）]，大于miR-148a及miR-106a单独检测，其cut-off值为0.315 3，敏感度为91，6%，特异度为64.1%。  结论  血清外泌体miR-148a联合miR-106a检测的2-△△CP值可以作为胃癌筛查的手段。      

miR-10a-5p基因甲基化对卵巢癌铂类耐药的影响

目的 卵巢癌是死亡率最高的妇科肿瘤,较强的化疗耐药性是其预后差的主要原因之一,为了阐明卵巢癌对铂类药物的耐药机制,本研究探讨miRNA基因的甲基化水平对卵巢癌铂类耐药的影响.方法 将卵巢癌组织分为敏感组和耐药组,每组各3例;采用基因芯片技术,对比分析了两组微RNA(microRNA,miRNA)的表达差异;采用实时荧光定量PCR,分别在6例敏感和3例耐药组织、铂类药物敏感(CoC1)和耐药的卵巢癌细胞系(CoC1/DDP),检测了候选miRNA的表达差异;应用Massarray技术,检测敏感组织(15例)与耐药组织(6例)中miRNA基因启动子的甲基化差异;应用生物信息学分析,鉴定目标miRNA的潜在靶基因.结果 以铂类药物敏感的卵巢癌组织样本为对照,利用基因芯片筛选,鉴定了6条在耐药组织样本中出现表达上调的miRNA(miR-493-3p、miR-10a-5 p、miR-16-2-3p、miR-1248、miR-451a、miR-628-3p)和6条表达下调的miRNA(miR-509-3p、miR-1197、miR-376a-3p、miR-1273a、miR-550a-3p、miR-19b-3p).组织验证发现,miR-509-3p、miR-493-3p、miR-10a-5p、miR-16-2-3p和miR-451a,与芯片结果一致;培养细胞研究发现,4条miRNA的表达调控方式与组织芯片结果一致,miR-10a-5p、miR-16-2-3p、miR-1248和miR-628-3p在耐药细胞系中高表达.进一步研究发现,与敏感肿瘤组织相比,耐药组织中miR-10a-5p基因启动子的甲基化水平出现显著降低,P=0.04.结合生物信息学预测HOXA1和USF2为miR-10a-5p与耐药相关的靶基因.结论 与敏感组相比,耐药组miR-10a-5p基因启动子甲基化水平显著降低,miR-10a-5p表达升高,通过抑制 HOXA1和USF2,抑制细胞凋亡,导致铂类化疗药物耐受.     

Exosomal microRNA panels as biomarkers for hematological malignancies

Hematological malignancies are classified as a heterogeneous category of cancers with various degrees of incidence and prognosis and different etiologies. Due to their aggressive essence they should be diagnosed as early as possible to improve prognosis, treatment outcome and survival. Bases on the limitations of previously identified biomarkers in terms of sensitivity, specificity and predictability, it is necessary to develop new diagnostic tools and biomarkers for the early diagnosis of hematological malignancies. Exosomes are nanovesicles secreted by almost all cell types in both physiological and pathological conditions. They play major roles in intercellular communication and are recently being considered as disease biomarkers. These nanovesicles carry proteins, lipids and nucleic acids like microRNAs (miRNAs). miRNAs are small noncoding RNAs, which act as translational suppressors via regulating protein-coding genes. The aberrant expression of miRNAs has been shown in various conditions including hematological malignancies. Moreover, it is now known that tumor cells secrete higher amounts of exosomes compared to normal cells. The idea of using exosomal miRNAs in serum as biomarkers is based on their surprisingly high stability and specificity. In the present paper, we reviewed and recommended exosomal miRNA panels including (miR-150, miR-155 and miR-1246), (miR-17-5p, miR-20a-5p, miR-16-5p and miR-5a-5p), (miR-18a, Let-7b) and (miR192-5p, miR21-5p, miR320b and Let-7d), for their potential to be used as non-invasive biomarkers in different hematological malignancies such as multiple myeloma, leukemia, and lymphoma.     

miR-451 抑制肝癌HepG2 细胞增殖及其在肝癌诊断和预后中的作用

[摘要] 目的：寻找用于肝癌诊断的miRNA分子靶标,探讨其在肝癌细胞增殖及细胞周期中的作用及其机制。方法：通过对TCGA数据库中377 例肝癌样本和37 例癌旁样本的miRNAs 表达数据资料进行统计分析,得到一组包含33 个差异表达的miRNA。对差异表达的miRNA采用受试者工作特征曲线（ROC曲线）和Kaplan-Meier 生存分析进行进一步的筛选,同时结合现有文献最终选择miR-451 作为研究目标。向人肝癌细胞株HepG2 转染pLVX-shRNA2-miR-451,使之过表达miR-451,通过CCK-8 细胞增殖实验检测其对HepG2 细胞增殖能力的影响,用流式细胞术观察对HepG2 细胞细胞周期的影响。结果：miR-451 在肝癌组织中的表达水平明显低于癌旁组织[ （473.40±390.24) vs (1 990.47±2 118.04),P<0.05],且可以作为肝癌诊断的标志物,ROC值为0.91（敏感度0.89,特异性0.87）。体外实验结果表明,过表达miR-451 后肝癌HepG2 细胞增殖能力明显降低[48 h：(0.69±0.04) vs(1.08±0.05);72 h：(0.76±0.07) vs (1.52±0.02);均P<0.01],大量细胞被阻滞于S 期（P<0.05）。结论：miR-451 不但可以作为诊断肝癌和指示预后的生物标志物,还具有抑制肝癌细胞增殖的作用。     

Integrated miRNA and mRNA expression profiling of the inflammatory breast cancer subtype

Background:

MicroRNAs (miRNAs) are key regulators of gene expression. In this study, we explored whether altered miRNA expression has a prominent role in defining the inflammatory breast cancer (IBC) phenotype.

Methods:

We used quantitative PCR technology to evaluate the expression of 384 miRNAs in 20 IBC and 50 non-IBC samples. To gain understanding on the biological functions deregulated by aberrant miRNA expression, we looked for direct miRNA targets by performing pair-wise correlation coefficient analysis on expression levels of 10 962 messenger RNAs (mRNAs) and by comparing these results with predicted miRNA targets from TargetScan5.1.

Results:

We identified 13 miRNAs for which expression levels were able to correctly predict the nature of the sample analysed (IBC vs non-IBC). For these miRNAs, we detected a total of 17 295 correlated miRNA–mRNA pairs, of which 7012 and 10 283 pairs showed negative and positive correlations, respectively. For four miRNAs (miR-29a, miR-30b, miR-342-3p and miR-520a-5p), correlated genes were concordant with predicted targets. A gene set enrichment analysis on these genes demonstrated significant enrichment in biological processes related to cell proliferation and signal transduction.

Conclusions:

This study represents, to the best of our knowledge, the first integrated analysis of miRNA and mRNA expression in IBC. We identified a set of 13 miRNAs of which expression differed between IBC and non-IBC, making these miRNAs candidate markers for the IBC subtype.     

A novel signaling role for miR-451 in esophageal tumor microenvironment and its contribution to tumor progression

Objective

We evaluated miR-451 expression in serum and tissue samples of esophageal squamous cell carcinoma (ESCC) patients. Then, we examined a secretory role of miR-451 in esophageal tumor microenvironment.

Methods

miR-451 expression was evaluated in 39 serum samples from esophageal SCC patients compared to 39 normal individuals as well as 26 pairs of fresh-frozen tumor and adjacent normal tissues from patients with ESCC, using qRT-PCR. In a co-culture system of human normal fibroblasts (HFSF-PI3) and esophageal cancer cell line (KYSE-30), we evaluated exosomal miR-451 secretion into the conditioned medium (CM) of both cell lines. Then, we analyzed the effect of primiR-451-transfected fibroblasts on the migration potency of their neighboring KYSE-30 cells.

Results

We detected miR-451 over-expression in serum samples of esophageal cancer patients compared to the normal group (P = 0.005). Interestingly, fresh-frozen tumor tissues from the same patients showed miR-451 down-regulation compared to their adjacent normal counterparts (P = 0.043). Co-culturing the KYSE-30 cell line with normal fibroblasts significantly induced miR-451 exosomal secretion into the CM. Moreover, co-culture of KYSE-30 cell line with miR-451-over-expressing fibroblasts significantly induced migration tendency in KYSE-30 cell line compared to the mock-transfected fibroblasts (P < 0.0001). In this system, MIF expression (a validated target of miR-451) in the KYSE-30 cell line was increased although this alteration was not statistically significant (fold change = 4.44).

Conclusions

Our data suggest that cancer-associated fibroblasts use exosomal miR-451 as a signaling molecule to provide a favorable niche for tumor cell migration and cancer progression. Our findings provide new insights into the stromal role of miR-451 in the esophageal tumor microenvironment as a communicatory molecule and suggest a signaling role for miR-451 in extracellular matrix cross-talks.

     

Exosomal miRNA profiles of triple-negative breast cancer in neoadjuvant treatment

Triple-negative breast cancer (TNBC) is characterized by aggressive clinicopathological features and is associated with a poor prognosis. Identifying patients that are non-responsive to chemotherapy remains a critical goal for effective personalized therapies. In the present study, the predictive value of exosomal microRNAs (miRNAs) was investigated in patients with TNBC. Exosomes were isolated from patients with TNBC undergoing neoadjuvant chemotherapy. Microarray-based miRNA profiles were compared between patients with pathological complete response (pCR; n=12) and non-pCR (n=12). Furthermore, the miRNA profiles of non-pCR patients with breast cancer recurrence were compared with those with no recurrence. A total of 16 differentially expressed exosomal miRNAs were identified between the patients with pCR and non-pCR by microarray analysis. Of these, a combined signature of four miRNAs (miR-4448, miR-2392, miR-2467-3p and miR-4800-3p) could be used to discriminate between pCR and non-pCR patients with TNBC with an area under the curve value of 0.7652. Furthermore, this study found 43 differentially expressed miRNAs between the patients with non-pCR and recurrence and non-pCR patients without recurrence. In network analysis, ‘pathway in cancer’, ‘focal adhesion’ and ‘cell cycle’ were identified as the crucial pathways in patients with non-pCR who also developed recurrence. Several exosomal miRNAs may be useful biomarkers to predict treatment efficacy for TNBC. The present study identified patients who were resistant to standard chemotherapy and therefore more likely to develop breast cancer recurrence.