Serum exosomal microRNAs as novel biomarkers for multiple myeloma

Accumulating studies have focused on circulating microRNAs, which might be potential biomarkers for different malignancies. The aim of this study was to investigate the potential of serum exosomal microRNAs to be novel serum biomarkers for smouldering myeloma (SMM) or even multiple myeloma (MM). The levels of serum exosomal microRNAs and serum circulating microRNAs were measured in healthy individuals and patients with SMM (n = 20) or MM (n = 20). Serum exosomal microRNAs and serum circulating microRNAs were extracted from serum, and the expression levels of selected microRNAs were quantified by real‐time polymerase chain reaction (PCR). The levels of serum exosome‐derived miR‐20a‐5p, miR‐103a‐3p, and miR‐4505 were significantly different among patients with MM, patients with SMM, and healthy individuals, while there were differences in the levels of let‐7c‐5p, miR‐185‐5p, and miR‐4741 in patients with MM relative to those in SMM patients or healthy controls. Additionally, a significant correlation was rarely found between the levels of serum and exosomal microRNAs. This study shows that serum exosomal microRNAs can be used independently as novel serum biomarkers for MM.     

Plasma microRNAs as biomarkers of pancreatic cancer risk in a prospective cohort study

Noninvasive biomarkers for early pancreatic ductal adenocarcinoma (PDAC) diagnosis and disease risk stratification are greatly needed. We conducted a nested case‐control study within the Prospective Investigation into Cancer and Nutrition (EPIC) cohort to evaluate prediagnostic microRNAs (miRs) as biomarkers of subsequent PDAC risk. A panel of eight miRs (miR‐10a, ‐10b, ‐21‐3p, ‐21‐5p, ‐30c, ‐106b, ‐155 and ‐212) based on previous evidence from our group was evaluated in 225 microscopically confirmed PDAC cases and 225 controls matched on center, sex, fasting status and age/date/time of blood collection. MiR levels in prediagnostic plasma samples were determined by quantitative RT‐PCR. Logistic regression was used to model levels and PDAC risk, adjusting for covariates and to estimate area under the receiver operating characteristic curves (AUC). Plasma miR‐10b, ‐21‐5p, ‐30c and ‐106b levels were significantly higher in cases diagnosed within 2 years of blood collection compared to matched controls (all p‐values <0.04). Based on adjusted logistic regression models, levels for six miRs (miR‐10a, ‐10b, ‐21‐5p, ‐30c, ‐155 and ‐212) overall, and for four miRs (‐10a, ‐10b, ‐21‐5p and ‐30c) at shorter follow‐up time between blood collection and diagnosis (≤5 yr, ≤2 yr), were statistically significantly associated with risk. A score based on the panel showed a linear dose‐response trend with risk (p‐value = 0.0006). For shorter follow‐up (≤5 yr), AUC for the score was 0.73, and for individual miRs ranged from 0.73 (miR‐212) to 0.79 (miR‐21‐5p).     

Exosome‐encapsulated microRNAs as circulating biomarkers for breast cancer

Breast cancer is a highly prevalent disease, accounting for 29% of invasive cancers in women. Survival from this disease depends on the stage at diagnosis, with patients who are detected earlier having more favourable outcomes. It is because of this that research groups are focusing on the development of a blood‐based biomarker for breast cancer. Such biomarkers may facilitate the detection of breast cancer in its infancy before it has spread beyond the primary site. MicroRNAs (miRNAs) have shown immense potential in this setting. These short, non‐coding RNA sequences have been shown to be dysregulated in breast cancer. Despite showing immense promise, miRNAs have not been successfully implemented in the clinical setting due to a lack of a standardised approach which has resulted in conflicting results. These challenges may be addressed at least in part through the study of exosomes. The biomarker potential for exosomes holds huge promise and may revolutionise the way in which we diagnose and manage breast cancer. These nanovesicles may be isolated from a variety of bodily fluids, including serum, and their miRNA content has been shown to reflect that of the parent breast cancer cell. This review will highlight the nomenclature and defining characteristics of exosomes, and current methods of isolation of serum‐derived exosomes. Initial promising reports on the potential utility of exosomal miRNAs to be used as breast cancer biomarkers will also be addressed.     

Circulating biomarkers for detection of ovarian cancer and predicting cancer outcomes

Background:

Securing a diagnosis of ovarian cancer and establishing means to predict outcomes to therapeutics remain formidable clinical challenges. Early diagnosis is particularly important since survival rates are markedly improved if tumour is detected early.

Methods:

Comprehensive miRNA profiles were generated on presurgical plasma samples from 42 women with confirmed serous epithelial ovarian cancer, 36 women diagnosed with a benign neoplasm, and 23 comparably age-matched women with no known pelvic mass.

Results:

Twenty-two miRNAs were differentially expressed between healthy controls and the ovarian cancer group (P<0.05), while a six miRNA profile subset distinguished presurgical plasma from benign and ovarian cancer patients. There were also significant differences in miRNA profiles in presurgical plasma from women diagnosed with ovarian cancer who had short overall survival when compared to women with long overall survival (P<0.05).

Conclusion:

Our preliminary data support the utility of circulating plasma miRNAs to distinguish women with ovarian cancer from those with a benign mass and identify women likely to benefit from currently available treatment for serous epithelial ovarian cancer from those who may not.     

多发性骨髓瘤生物标志物研究进展

多发性骨髓瘤(Multiple myeloma,MM)是一种克隆性浆细胞异常增殖的恶性疾病,在大多数国家是第二位常见的血液系统恶性肿瘤,其发病率约占全部恶性肿瘤的1%,约占血液系统恶性肿瘤的10%,在癌症相关死亡中占0.9%。目前临床上的分期和预后评估系统主要包括国际分期系统(ISS)、修订的国际分期系统(R-ISS)、mSMART分期以及国际骨髓瘤工作组(IMWG)分层标准,主要基于肿瘤生物学、肿瘤负荷和患者特征,而没有考虑免疫及微环境相关的因素,原因之一是缺乏易于获取的生物标志物。近几年,随着液体活检、分子生物学和细胞遗传学等新技术的发展,发现了许多MM相关的新型生物标志物,为MM早期诊断和预后评估提供了新方法。在这篇综述中,将从免疫因素、骨髓微环境、细胞遗传学及液体活检等几个方面论述MM生物标志物的研究进展。     

多发性骨髓瘤分型的进展

 关于多发性骨髓瘤的分型,目前临床上常规根据其分泌M蛋白成分的不同进行分型,并依据Durie-Salmon 分期标准和ISS分期系统进行分期。此外,人们还根据骨髓瘤细胞染色体的异常以及荧光原位杂交（FISH）检测的结果进行分型,其中最常见的细胞遗传学异常有del(13), t(4;14)(p16;q32), del 17p等。随着比较基因组杂交（CGH）、FISH 及基因表达谱等分子生物学研究技术的进步和广泛运用,人们正在探索诸如TC分期系统,UAMS分子分期系统及基因表达谱预后模型以提示多发性骨髓瘤的预后和指导治疗。     

Identification of predictive circulating biomarkers of bevacizumab-containing regimen efficacy in pre-treated metastatic colorectal cancer patients

Background:

To identify whether circulating levels of angiogenesis-related factors may be predictive of bevacizumab efficacy in pre-treated metastatic colorectal cancer (mCRC) patients.

Methods:

Pre-treatment serum levels of 24 cytokines were measured using a multiplex bead assay (MBA) in 32 pre-treated mCRC patients treated with irinotecan plus bevacizumab-based salvage therapy. Macrophage-derived chemokine (MDC), interleukins (ILs) 8 and 6 levels were also validated by enzyme-linked immunosorbent assay (ELISA) at different time points during therapy.

Results:

Higher epidermal growth factor (EGF) and MDC baseline levels (2.2- and 1.4-fold, respectively) and lower IL-10, IL-6 and IL-8 levels (0.2-, 0.6-, and 0.6-fold, respectively, P<0.05) were observed in patients responding to therapy. Baseline levels of these five serum factors compose a risk signature that may define the subset of patients most likely to benefit from bevacizumab-based therapy in terms of response rate and survival times. A positive correlation was found between MBA and ELISA results (P<0.01). Treatment exposure increased MDC and had opposite effects on IL-8 levels, which were decreased (P<0.05).

Conclusion:

This study suggests that a set of inflammatory and angiogenesis-related serum markers may be associated with the efficacy of bevacizumab-containing regimen.     

Genome-wide pharmacologic unmasking identifies tumor suppressive microRNAs in multiple myeloma

Epigenetic alterations have emerged as an important cause of microRNA (miRNA) deregulation. In Multiple Myeloma (MM), a few tumor suppressive miRNAs silenced by DNA hypermethylation have been reported, but so far there are few systemic investigations on epigenetically silenced miRNAs. We conducted genome-wide screening for tumor suppressive miRNAs epigenetically silenced in MM. Four Human MM Cell lines were treated with demethylating agent 5′azacytidine (5′aza). Consistently upregulated miRNAs include miR-155, miR-198, miR-135a*, miR-200c, miR-125a-3p, miR-188-5p, miR-483-5p, miR-663, and miR-630. Methylation array analysis revealed increased methylation at or near miRNA-associated CpG islands in MM patients. Ectopic restoration of miR-155, miR-198, miR-135a*, miR-200c, miR-663 and miR-483-5p significantly repressed MM cell proliferation, migration and colony formation. Furthermore, we derived a 33-gene signature from predicted miRNA target genes that were also upregulated in MM patients and associated with patient survival in three independent myeloma datasets. In summary, we have revealed important, epigenetically silenced tumor suppressive miRNAs by pharmacologic reversal of epigenetic silencing.     

Identification of 9 serum microRNAs as potential noninvasive biomarkers of human astrocytoma

BackgroundCirculating microRNAs (miRNAs) are emerging as promising biomarkers for human cancer. In the current study, we investigated the potential use of serum miRNAs as biomarkers for diagnosis and prognosis in a cohort of Chinese astrocytoma patients.MethodsAn initial screening of the circulating miRNA expression profile was performed on pooled serum samples from 10 preoperative patients and 10 healthy controls using a TaqMan low-density array. The selected serum miRNAs were then validated in 90 preoperative patients and 110 healthy controls who were randomly divided into a training set and a validation set. An additional double-blind test was performed in 50 astrocytomas and 50 controls to assess the serum miRNA-based biomarker accuracy in predicting astrocytoma. The differentially expressed miRNAs were evaluated in paired preoperative and postoperative serum samples from 73 astrocytoma patients. The correlation of the miRNA levels with survival in astrocytoma samples was estimated.ResultsNine serum miRNAs were significantly increased in the astrocytoma patients. The biomarker composed of these 9 miRNAs had high sensitivity, specificity, and accuracy. These 9 miRNAs were markedly decreased in the serum after operation. The upregulation of miR-20a-5p, miR-106a-5p, and miR-181b-5p was associated with advanced clinical stages of astrocytoma. Kaplan-Meier survival analysis showed that the high expression of miR-19a-3p, miR-106a-5p, and miR-181b-5p was significantly associated with poor patient survival. Finally, the combined 3-miRNAs panel was an important prognostic predictor, independent of other clinicopathological factors.ConclusionsThe results indicated the potential of serum miRNAs as novel diagnostic and prognostic biomarkers for human astrocytoma.     

Identification and validation of potential prognostic lncRNA biomarkers for predicting survival in patients with multiple myeloma

Background

Dysregulated long non-coding RNAs (lncRNAs) have been found to have oncogenic and/or tumor suppressive roles in the development and progression of cancer, implying their potentials as novel independent biomarkers for cancer diagnosis and prognosis. However, the prognostic significance of expression profile-based lncRNA signature for outcome prediction in patients with multiple myeloma (MM) has not yet been investigated.

Methods

LncRNA expression profiles of a large cohort of patients with MM were obtained and analyzed by repurposing the publically available microarray data. An lncRNA-focus risk score model was developed from the training dataset, and then validated in the testing and another two independent external datasets. The time-dependent receiver operating characteristic (ROC) curve was used to evaluate the prognostic performance for survival prediction. The biological function of prognostic lncRNAs was predicted using bioinformatics analysis.

Results

Four lncRNAs were identified to be significantly associated with overall survival (OS) of patients with MM in the training dataset, and were combined to develop a four-lncRNA prognostic signature to stratify patients into high-risk and low-risk groups. Patients of training dataset in the high-risk group exhibited shorter OS than those in the low-risk group (HR = 2.718, 95 % CI = 1.937-3.815, p <0.001). The similar prognostic values of four-lncRNA signature were observed in the testing dataset, entire {"type":"entrez-geo","attrs":{"text":"GSE24080","term_id":"24080"}}GSE24080 dataset and another two independent external datasets. Multivariate Cox regression and stratified analysis showed that the prognostic power of four-lncRNA signature was independent of clinical features, including serum beta 2-microglobulin (Sβ2M), serum albumin (ALB) and lactate dehydrogenase (LDH). ROC analysis also demonstrated the better performance for predicting 3-year OS. Functional enrichment analysis suggested that these four lncRNAs may be involved in known genetic and epigenetic events linked to MM.

Conclusions

Our results demonstrated potential application of lncRNAs as novel independent biomarkers for diagnosis and prognosis in MM. These lncRNA biomarkers may contribute to the understanding of underlying molecular basis of MM.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0219-5) contains supplementary material, which is available to authorized users.     

Potential relationship and clinical significance of miRNAs and Th17 cytokines in patients with multiple myeloma

We evaluated the potential relationship between miRNAs and Th17 cytokines in multiple myeloma (MM) patients. Twenty-seven newly diagnosed myeloma patients and eight normal donors were studied. We determined that the relative expression levels of miR-15a/16, miR-34a, miR-194 in MM patients were significantly lower than those in the healthy controls with exception for miR-181a/b, which showed significantly higher in MM patients (P < 0.05). In contrast, the levels of IL-17, IL-21 and IL-27 were up-regulated in MM patients compared to healthy controls while IL-22 was down-regulated (P < 0.05). The expression patterns of them were differentially present in various groups according to the International Staging System (ISS) criteria. Up-regulated IL-17, IL-21 and IL-27 may potentially down-regulate the expression of several miRNAs in MM patients. Establishment of the relationship may be useful for understanding the pathogenesis of MM and for clinical diagnosis of the disease.     

Identification of circulating microRNAs as biomarkers in diagnosis of hematologic cancers: a meta-analysis

Recent studies have provided new insights into the diagnostic value of circulating microRNAs (miRNAs) for hematologic cancers. However, inconsistent results have been reported on the diagnostic performance of various kinds of miRNAs. To systematically assess the potential diagnostic value of miRNAs in hematologic cancers, we conducted the present meta-analysis. Multiple databases (PubMed, Cochrane Library, EMBASE, CNKI, and Wan Fang) were carefully searched for available studies up to April 4, 2014. Sensitivity and specificity were pooled using a random-effects model. Likelihood ratio (LR), diagnostic odds ratio (DOR), and the area under the curve (AUC) were used to measure the diagnostic values. Subgroup and meta-regression analyses were used to find potential sources of heterogeneity. Thirty-four studies from 14 publications, which involved 1,159 hematologic cancer patients and 826 healthy controls, were included in this meta-analysis. The pooled estimates indicated a moderately high diagnostic accuracy for circulating miRNAs, with a sensitivity of 0.83, a specificity of 0.85, a PLR of 5.7, a NLR of 0.20, a DOR of 29, and an AUC of 0.91. The subgroup analyses showed that diagnostic accuracy was better for acute myeloid leukemia (AML) patients and Asians compared with other subgroups. In addition, multiple miRNA assays displayed a better performance than single ones. Furthermore, we found that plasma might be a more promising matrix for detecting the expression of miRNAs than serum. Our results identified the potential use of circulating miRNAs in second-line diagnosis for hematologic cancers, especially the value of miRNA panels. However, further large cohort studies are still required to confirm our findings.     

microRNAs在肿瘤干细胞中的研究进展

microRNAs（miRNAs）是一类非编码的小RNA,在肿瘤发生发展及侵袭转移中发挥着至关重要的作用。肿瘤干细胞是导致恶性肿瘤复发、转移和耐药的主要根源。研究发现miRNAs可以促进或抑制肿瘤干细胞“干性”的维持,调控肿瘤干细胞的分化及自我更新,从而参与肿瘤的发生发展过程。本文详细介绍了肿瘤干细胞中miRNAs的表达情况及调控机制,阐述其在肿瘤诊断及治疗中的潜在作用。     

Circulating miR-148b and miR-133a as biomarkers for breast cancer detection

Circulating microRNAs have drawn a great deal of attention as promising novel biomarkers for breast cancer. However, to date, the results are mixed. Here, we performed a three-stage microRNA analysis using plasma samples from breast cancer patients and healthy controls, with efforts taken to address several pitfalls in detection techniques and study design observed in previous studies. In the discovery phase with 122 Caucasian study subjects, we identified 43 microRNAs differentially expressed between breast cancer cases and healthy controls. When those microRNAs were compared with published data from other studies, we identified three microRNAs, including miR-148b, miR-133a and miR-409-3p, whose plasma levels were significantly higher in breast cancer cases than healthy controls and were also significant in previous independent studies. In the validation phase with 50 breast cancer cases and 50 healthy controls, we validated the associations with breast cancer detection for miR-148b and miR-133a (P = 1.5×10⁻⁶ and 1.3×10⁻¹⁰, respectively). In the in-vitro study phase, we found that both miR-148b and miR-133a were secreted from breast cancer cell lines, showing their secretory potential and possible tumor origin. Thus, our data suggest that both miR-148b and miR-133a have potential use as biomarkers for breast cancer detection.     

Current progress in the clinical use of circulating tumor cells as prognostic biomarkers

The process of metastasis is characterized by the shedding of tumor cells into the bloodstream, where they are transported to other parts of the body to seed new tumors. These cells, known as circulating tumor cells (CTCs), have the potential to reveal much about an individual cancer case, and theoretically can aid in the prediction of outcomes and design of precision treatments. Recent advances in technology now allow for the robust and reproducible characterization of CTCs from a simple blood draw. Both the number of circulating cells and important molecular characteristics correlated with clinical phenotypes such as drug resistance can be obtained and used for real-time prognostic analysis. Molecular characterization can provide a snapshot of the activity of the main tumor (serving as a “liquid biopsy”) and early warnings concerning changes such as the development of resistance, and aid in predicting the efficacy of different therapeutic approaches for treatment optimization. Herein, the authors review the current clinical use of CTCs as prognostic biomarkers for several different cancers. The quantification of CTCs can lead to more accurate staging and decision making regarding options such as adjuvant chemotherapy.