Serum miR-122 Levels Research Articles

Serum MicroRNAs in HIV-Infected Individuals as Pre-Diagnosis Biomarkers for AIDS-NHL

To determine if changes in levels of serum microRNAs (miRNAs) were seen preceding the diagnosis of AIDS-related non-Hodgkin lymphoma (AIDS-NHL). Serum miRNA levels were compared in 3 subject groups from the Multicenter AIDS Cohort Study: HIV-negative men (n = 43), HIV-positive men who did not develop NHL (n = 45), and HIV-positive men before AIDS-NHL diagnosis (n = 62, median time before diagnosis, 8.8 months). A total of 175 serum-enriched miRNAs were initially screened to identify differentially expressed miRNAs among these groups and the results validated by quantitative polymerase chain reaction. Receiver-operating characteristic analysis was then performed to assess biomarker utility. Higher levels of miR-21 and miR-122, and a lower level of miR-223, were able to discriminate HIV-infected from the HIV-uninfected groups, suggesting that these miRNAs are biomarkers for HIV infection but are not AIDS-NHL specific. Among the HIV-infected groups, a higher level of miR-222 was able to discriminate diffuse large B-cell lymphoma (DLBCL) and primary central nervous system lymphoma (PCNSL) subjects from HIV-infected subjects who did not develop NHL, with area under the receiver-operating characteristic curve of 0.777 and 0.792, respectively. At miR-222 cutoff values of 0.105 for DLBCL and 0.109 for PCNSL, the sensitivity and specificity were 75% and 77%, and 80% and 82%, respectively. Altered serum levels of miR-21, miR-122, and miR-223 are seen in HIV-infected individuals. Higher serum level of miR-222 has clear potential as a serum biomarker for earlier detection of DLBCL and PCNSL among HIV-infected individuals.

MiR-21: A Non-invasive Biomarker and Potential Therapeutic Target for Lung Cancer?

We read with great interest the article, published in Cell Biochem Biophys, showing that serum level of miR-21 was significantly elevated in lung cancer patients compared with controls. Receiver operating characteristic (ROC) curve analysis showed that miR-21 could differentiate lung cancer from healthy controls with an AUC (the area under the curve) of 0.85, and the optimal sensitivity and specificity were 85.7 and 86.5 %, respectively [1]. These findings suggest that miR-21 can be a potential non-invasive biomarker for lung cancer patients and miR-21 may be a potential therapeutic target for lung cancer. Lung cancer is one of the most common malignant tumors and is the leading cause of cancer mortality in the world [2]. Non-small cell lung cancer (NSCLC) accounts for approximately 80–85 % of all cases of lung cancer [3]. Despite much advances in lung cancer therapy, the survival rate for lung cancer patients remains very poor [4]. Recent advances in functional genomics provide an increasingly comprehensive portrayal of lung tumorigenesis, but the molecular pathogenesis of lung cancer remains poorly understood. These findings highlight the need for a better understanding of novel molecular mechanisms to guide treatment of lung cancer. MicroRNAs (miRNAs) are small non-coding RNAs that repress target gene expression by a combination of mRNA degradation and translation inhibition [5]. Recently, miR-21 expression was found to be higher in lung cancer serum samples than in control serum samples [3, 6–9]. High serum miR-21 was significantly correlated with tumor node metastases stage and lymph node metastasis of NSCLC patients [3, 5]. Overexpression of miR-21 showed a highly discriminative ROC curve profile, clearly distinguishing cancer patients from cancer-free subjects, and the detection of miR-21 expression yielded high sensitivity and specificity in the diagnosis of lung cancer [7–9]. Furthermore, miR-21 expression was elevated in human lung cancer cell lines (NCI-H446 and NCI-H460) [2]. Human mutS homolog 2 (hMSH2), one of the core mismatch repair genes, is affected in lung cancer development. Zhong et al. [2] found that hMSH2 was directly regulated by miR-21, and miR-21 expression was inversely correlated with hMSH2 expression in human lung cancer cell lines [2]. Notably, upregulation of miR-21 markedly promoted cell proliferation and revealed a higher proportion of cells at S phase. However, knockdown of miR-21 expression led to cell cycle arrest at G2/M phase and inhibited cell proliferation [2]. Similarly, tumor tissues showed an inverse correlation between high expression of miR-21 and low amounts of PTEN protein, where miR-21 suppresses PTEN by direct binding to the 30-UTR of PTEN [5]. Lung cancer cell lines (A549, H1703, and 801D) transfected with miR-21 inhibitor showed decreased endogenous miR-21 levels but significantly increased PTEN protein expression [5]. In addition, A549 and H1703 cells transfected with miR-21 inhibitor could restrain the growth of A549 and H1703 cells, and downregulation of miR-21 with miR-21 inhibitor in 801D cells could restrain its invasion ability [5]. Collectively, available evidence suggests that miR-21 may be a good biomarker for detection of lung cancer, and miR-21 may play an important role in lung cancer. However, further studies, especially in human systems, are needed to comprehensively explore the role of miR-21 in lung cancer, and miR-21 may be a potential therapeutic target for lung cancer. S.-C. Wang (&) Y.-F. Zhang Q. Xie PET/CT Center, Anhui Provincial Hospital, 17 Lujiang Road, Hefei 230001, Anhui, People’s Republic of China e-mail: wangsc3329@163.com

MicroRNA-21 is a unique signature associated with coronary plaque instability in humans by regulating matrix metalloproteinase-9 via reversion-inducing cysteine-rich protein with Kazal motifs

BackgroundCoronary atherosclerotic unstable plaque is one of the leading causes of cardiovascular death. Macrophage-derived matrix metalloproteinase (MMP) 9 is considered for degrading extracellular matrix and collagen, thereby thinning the fibrous cap in plaques. miR-21 is implicated to play an important role in the progression of atherosclerosis. Nevertheless, miR-21 as the biomarker for coronary atherosclerotic unstable plaque remains unknown. We aimed to investigate the prediction role of miR-21 for unstable plaque by pathway study of miR-21 on MMPs and its inhibitor RECK in macrophages. MethodsExpression of miR-21 in macrophages and serum miR-21 as well as MMP-9 was measured in patients with coronary non-calcified plaque, calcified plaque and controls. In vitro experiment was done in human macrophages by over-expressing miR-21 or down-regulating RECK. The regulation of RECK and MMP-9 by miR-21 was evaluated by western blotting and siRNA strategy. ResultsPatients with non-calcified coronary artery lesions had significantly higher miR-21 in macrophages and lower miR-21 serum levels compared to the control and calcified plaque patients. At the same time, the serum levels of MMP-9 were significantly elevated in non-calcified patients. Experiments in vitro indicated that over-expressing miR-21 could induce the expression and secretion of pro-MMP-9 and active-MMP-9 in human macrophages via targeting gene RECK, and knocking down RECK expression by specific siRNA can resemble that of miR-21 over-expression. ConclusionsmiR-21 might be a biomarker for plaque instability by suppressing target gene RECK to promote the expression and secretion of MMP-9 in macrophages.

Serum microRNA-21 as a Potential Biomarker for Response to Hypomethylating Agents in Myelodysplastic Syndromes

Identification of biomarkers that predict responses to hypomethylating agents (HMAs) will allow optimal strategies for epigenetic therapy in myelodysplastic syndromes (MDS) to be established. Serum miR-21 was quantitatively measured in 58 MDS patients treated with HMAs and 14 healthy controls. Serum miR-192 was an internal control, and diagnostic performance was evaluated according to receiver operating characteristics (ROCs). ROC analysis indicated that serum miR-21 levels differentiated responders from non-responders with an area under the curve of 0.648 (95% confidence, 0.49 to 0.72). The baseline level of serum miR-21 was significantly lower in the responder group than in the non-responder group (P = 0.041). The overall response rate (ORR) of the high miR-21 group was significantly lower than that of the low miR-21 group (41.2 vs. 73.2%, P = 0.021). Progression-free survival (PFS) was significantly inferior in the high group versus the low group (14.0 vs. 44.5 months, P = 0.001). Multivariate analyses revealed that the initial serum miR-21 level (P = 0.001) and circulating blasts (P = 0.007) were prognostic factors for PFS. Serum miR-21 level was significantly associated with ORR and PFS in MDS patients treated with HMAs. Although validation with a large prospective study is required, serum miR-21 is a potential biomarker of epigenetic therapy in MDS patients.

Clinical translation of human microRNA 21 as a potential biomarker for exposure to ionizing radiation

This study investigated to what extent the serum microRNA 21 (miR-21) level alters in response to ionizing radiation (IR). Initially, we evaluated the appropriateness of our RNA extraction efficiency and microRNA assay in serum, and then investigated the serum miR-21 level in 4 patients with breast cancer in 4 stages: pre- and postoperation, at the beginning radiotherapy, and after 25 sessions of radiotherapy with a total of 50 Gy irradiation, as well as in 20 healthy volunteers. The initial analysis showed the appropriateness of our RNA extraction efficiency and microRNA assay in serum for identifying people exposed to IR. We then analyzed the serum miR-21 level in another group of 40 patients with breast cancer before and after radiotherapy. During our large-scale analysis, the miR-21 level before radiotherapy was comparable with healthy volunteers (P = 0.10) and increased significantly after radiotherapy (P < 0.001)-an indication that this could discriminate irradiated patients from nonirradiated ones with high specificity (75%) and sensitivity (80%). According to this study, serum miR-21 has the potential to be used as a biomarker for the identification of people exposed to ionizing radiation.

Significance of serum and hepatic microRNA‐122 levels in patients with non‐alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is believed to be a type of metabolic syndrome. MicroRNA-122 (miR-122) is the most abundant microRNA in the liver and is an important factor for the metabolism of glucose and lipids. In the present study, we examined the correlation between the hepatic and serum miR-122 expression levels and the clinicopathological factors of patients with NAFLD. We extracted the total RNA, along with preserved miRNAs, from liver biopsy samples of 67 patients with NAFLD. In 52 of these 67 patients, the total RNA was extracted from serum. The miR-122 that was obtained by quantitative reverse transcription-polymerase chain reaction was quantified using TaqMan MicroRNA assays. A significant correlation was detected between serum and hepatic miR-122 expression (correlation coefficient, 0.461; P=0.005). Patients with mild steatosis (<33%) showed significantly lower levels of hepatic miR-122 compared with patients with severe steatosis (>33%) (hepatic miR-122: mild/severe=2.158±1.786/4.836±7.506, P=0.0473; serum miR-122: mild/severe=0.002±0.005/0.007±0.001, P=0.0491). Moreover, hepatic and serum miR-122 levels were significantly higher in patients with mild fibrosis than in those with severe fibrosis (hepatic miR-122: mild/severe=5.201±7.275/2.394±1.547, P=0.0087; serum miR-122: mild/severe=0.008±0.011/0.002±0.004, P=0.0191). We found that the hepatic and serum miR-122 levels were associated with hepatic steatosis and fibrosis. The serum miR-122 level can be a useful predictive marker of liver fibrosis in patients with NAFLD.

Expression and clinical significance of miR-122 and miR-29 in hepatitis B virus-related liver disease.

MicroRNA molecules have been increasingly regarded as a diagnostic and prognostic marker of certain diseases. The aim of this study was to investigate the expression and clinical significance of miR-122 and miR-29 in liver disease related to hepatitis B virus infection. The serum levels of miR-122 and miR-29 in 20 patients with hepatocellular carcinoma (HCC), 20 patients with liver cirrhosis (LC), 29 patients with chronic hepatitis B (CHB), 20 cases of hepatitis B virus carriers (ASC), and 20 healthy controls (HC) were determined by a fluorescence real-time quantitative PCR method and then evaluated by clinical correlation analysis. Compared with the serum levels of miR-122 in the HC, LC, and ASC groups, those in patients with HCC and CHB were significantly increased. The serum levels of miR-29 in LC patients were lower than those in the healthy controls (P < 0.01). A positive correlation was observed between the expression of miR-122 and miR-29, and HBV DNA in patients with CHB. A negative correlation was found between miR-29 and α-fetoprotein in patients with HCC. The elevation in miR-122 was correlated with liver damage in CHB patients and with the pathogenesis of liver cancer in HCC patients. The decrease in miR-29 expression was related to the incidence of liver fibrosis. The detection of miR-122 and miR-29 may be useful in evaluating the inflammatory liver injury and fibrosis associated with chronic HBV infection.

Serum miR-122 levels are related to coagulation disorders in sepsis patients

Coagulation abnormalities may have a major impact on the outcome of sepsis in patients. This study aimed to explore the relationship between miRNA levels and coagulation disorders during sepsis. Blood samples from 123 sepsis patients were collected on the day of admission and another 45 sepsis patients on days 1, 3, 5, 7, 10, and 14 following admission to the intensive care unit. miR-223, miR-15a, miR-16, miR-122, miR-193b*, and miR-483-5p levels were evaluated by quantitative reverse transcription polymerase chain reaction. Based on the International Society on Thrombosis and Haemostasis (ISTH) Disseminated Intravascular Coagulation (DIC) score, sepsis patients were divided into coagulation abnormal (CA) group and coagulation normal (CN) group. Only the levels of miR-122 were significantly higher in CA patients than in CN patients (p<0.001). Serum levels of miR-122 were correlated to the serum activated partial thromboplastin time (APTT) ratios (R=0.426, p=0.008) and the fibrinogen (FIB; R=0.398, p=0.008) and antithrombin III (R=0.913, p<0.001) levels. In addition, Pearson's correlation coefficients for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) with miR-122 were 0.663 (p<0.001) and 0.445 (p=0.001), respectively. In the 45 patients, the miR-122 levels were significantly higher on day 1, 3, 7, and 10 in the CA group than in the CN group, and no difference in the ISTH-DIC scores was evident. Serum levels of miR-122 were correlated to the coagulation disorder in sepsis patients.

Predicting distant metastasis and chemoresistance using plasma miRNAs

In the clinic, predicting metastasis and chemoresistance takes high priority, but has not been well established. This study seeks to investigate whether dynamically monitoring serum microRNAs (miRNAs) can help predict metastasis, chemoresistance, and prognosis of colorectal cancer. Serum miR-155, miR-200c, and miR-210 levels in 15 patients with colon cancer were measured by real-time PCR at different time points post surgery and chemotherapy for 3 years. Significant increases in miR-155, miR-200c, and miR-210 levels were observed in the serum and tumor tissues of colon cancer patients compared to that of healthy subjects. After surgery and chemotherapy, the serum levels of these miRNAs in patients with good prognosis returned to normal levels found in healthy controls during the 3-year follow-up. In patients with recurrence and distant metastasis, serum miR-155, miR-200c, and miR-210 levels remained at an elevated level or became elevated again after a short period of decline. In patients with good response to chemotherapy for metastatic tumors, re-elevation of miR-155 was not significant compared to miR-200c and miR-210. In contrast, miR-155 re-elevated more significantly in patients not sensitized to chemotherapy than miR-200c and miR-210. Our study suggests that re-elevation or sustained elevation of serum miR-155 level after surgery and chemotherapy is a sign of chemoresistance in colon cancer, while high and/or re-elevated miR-155, miR-200c, and miR-210 levels implicate local recurrence and distant metastasis as well as poor prognosis.

Circulating microRNA 122 in the methionine and choline-deficient mouse model of non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease (NAFLD) and is a major cause of liver cirrhosis and hepatic failure. The methionine choline-deficient diet (MCD) is a frequently used hepatotoxicity animal model of NASH that induces hepatic transaminase (ALT, AST) elevations and hepatobiliary histological changes similar to those observed in human NASH. Liver-specific microRNA-122 (miR-122) has been shown as a key regulator of cholesterol and fatty acid metabolism in adult liver, and has recently been proposed as a sensitive and specific circulating biomarker of hepatic injury. The purpose of this study was to assess miR-122 serum levels in mice receiving an MCD diet for 0, 3, 7, 14, 28 and 56 days and compare the performance vs. routine clinical chemistry when benchmarked against the histopathological liver findings. MiR-122 levels were quantified in serum using RT-qPCR. Both miR-122 and ALT/AST levels were significantly elevated in serum at all timepoints. MiR-122 levels increased on average by 40-fold after 3 days of initiating the MCD diet, whereas ALT and AST changes were 4.8- and 3.3-fold, respectively. In general, miR-122 levels remained elevated across all time points, whereas the ALT/AST increases were less robust but correlated with the progressive severity of NASH as assessed by histopathology. In conclusion, serum levels of miR-122 can potentially be used as a sensitive biomarker for the early detection of hepatotoxicity and can aid in monitoring the extent of NAFLD-associated liver injury in mouse efficacy models.

Serum miR-210 as a potential biomarker of early clear cell renal cell carcinoma

Early detection and treatment are critical in the management of renal cell carcinoma (RCC). However, there is no standard serum biomarker to facilitate early diagnosis or prognostic stratification in patients with RCC. Recent reports suggest that circulating microRNAs (miRNAs) have great potential as biomarkers for diagnosis and prognosis in patients with several types of cancers. Further, many studies using miRNA microarray analysis demonstrated that miR-210 expression in clear cell carcinoma (CCC), which is the largest subtype of RCC, was significantly upregulated in tumor tissue. Therefore, we investigated whether serum miR-210 could be a useful biomarker for the diagnosis and progression of CCC. This study included 34 CCC patients and 23 healthy controls (HC). First, we analyzed tissue miR-210 levels in tumor tissues and matched normal tissues from the 34 CCC patients. Second, we investigated the serum miR-210 levels in the 34 CCC patients and the 23 HC patients. Real-time polymerase chain reaction (PCR) was used to measure miRNA levels. Moreover, we examined the correlation between serum miR-210 levels and the clinicopathological parameters. Among patients with CCC, expression of miR-210 was higher in tumor tissues compared to normal tissues (P<0.001). Serum miR-210 levels were higher in CCC patients compared to HCs (P=0.001). Receiver operating characteristic (ROC) curve analysis showed an area under the ROC curve (AUC) of 0.77 (95% confidence interval, 0.65-0.89) and a sensitivity and specificity of 65 and 83%, respectively. In addition, there was no significant association between serum miR-210 levels and age, sex, tumor size or existence of metastasis at diagnosis among the 34 CCC patients. In conclusion, serum miR-210 upregulation may occur in the early stage of CCC and serum miR-210 can be a useful biomarker for early CCC in humans.

Circulating Liver-Specific miR-122 as a Novel Potential Biomarker for Diagnosis of Cholestatic Liver Injury

BackgroundCirculating microRNA-122 (miR-122) has been increasingly reported to be a potential biomarker for drug-, viral-, alcohol- and chemical-induced liver injury. The present study was initiated to determine the potential of circulating miR-122 as a biomarker for cholestatic liver injury.MethodsBoth bile-duct ligation (BDL) mice and patients with biliary calculi were employed as cholestatic liver injury models, and serum miR-122 level was determined by stem-loop real-time reverse-transcription PCR (SLqRT-PCR). All quantitative PCR values were normalized to those for U6 RNA and calculated with the 2−△Ct method.ResultsSerum miR-122 increased significantly after BDL-induced cholestatic injury and showed a similar time course to ALT concentrations. Compared with the sham controls, BDL mice had increased serum levels of miR-122 by 24.36±12.86, 423.63±322.89, 4.43±2.02 and 12.23±8.92 folds after 1, 3, 7 and 14 days, respectively. Moreover, serum miR-122 level was substantially higher in patients with biliary calculi than that in the healthy control group. In addition, patients with severe liver injury showed significantly higher levels of serum miR-122 when compared with healthy controls or patients with mild or moderate liver injury. Furthermore, serum miR-122 was found to show significant diagnostic value for biliary calculi by yielding an AUC (the areas under the receiver operating characteristic curve) of 0.931 with 77.4% sensitivity and 96.4% specificity in discriminating biliary calculi from healthy controls.ConclusionCollectively, these data suggest that serum miR-122 has strong potential as a novel, specific and noninvasive biomarker for diagnosis of cholestasis-induced liver injury.

Prognostic significance of serum microRNA-210 levels in nonsmall-cell lung cancer

To investigate the levels of microRNA-210 (miR-210) in the serum of patients with nonsmall-cell lung cancer (NSCLC) and to determine whether there was a correlation with the prognosis of NSCLC patients following cisplatin-based chemotherapy. Quantitative real-time reverse transcription-polymerase chain reaction was used to measure the serum levels of miR-210 in patients with NSCLC and healthy age-matched control subjects. Correlations between serum miR-210 levels and clinicopathological factors and prognosis were investigated. Serum miR-210 was significantly upregulated in 60 patients with NSCLC compared with 30 healthy control subjects. Higher serum miR-210 levels were significantly correlated with the clinical stage and the presence of regional lymph node metastasis in patients with NSCLC. Serum miR-210 levels in patients that achieved a partial response following cisplatin-based chemotherapy were significantly lower than in patients with stable or progressive disease, and were similar to those in healthy control subjects. These findings suggest that serum miR-210 levels might be a novel diagnostic and prognostic marker of NSCLC.

Liver-specific microRNAs as biomarkers of nanomaterial-induced liver damage

Although nanomaterials are being used in various fields, their safety is not yet sufficiently understood. We have been attempting to establish a nanomaterials safety-assessment system by using biomarkers to predict nanomaterial-induced adverse biological effects. Here, we focused on microRNAs (miRNAs) because of their tissue-specific expression and high degree of stability in the blood. We previously showed that high intravenous doses of silica nanoparticles of 70 nm diameter (nSP70) induced liver damage in mice. In this study, we compared the effectiveness of serum levels of liver-specific or -enriched miRNAs (miR-122, miR-192, and miR-194) with that of conventional hepatic biomarkers (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) as biomarkers for nSP70. After mice had been treated with nSP70, their serum miRNAs levels were measured by using quantitative RT-PCR. Serum levels of miR-122 in nSP70-treated mice were the highest among the three miRNAs. The sensitivity of miR-122 for liver damage was at least as good as those of ALT and AST. Like ALT and AST, miR-122 may be a useful biomarker of nSP70. We believe that these findings will help in the establishment of a nanomaterials safety-assessment system.

Prognostic implications of serum microRNA-21 in colorectal cancer

MicroRNAs (miRNAs) are small, noncoding RNAs that are involved in carcinogenesis through postranscriptional gene regulatory activity. Few studies have focused on the detection of miR-21 in serum rather than in tissue. The current study aimed to measure serum miR-21 expression levels and to evaluate their association with the outcome of colorectal cancer (CRC). Blood samples were collected from 102 CRC patients undergoing surgery with curative intent. The expression levels of miR-21 were measured using a quantitative reverse transcription polymerase chain reaction (qRT-PCR). The results were analysed to assess the relationship between serum miR-21 levels and patient survival. A univariate analysis revealed that lower expression levels of serum miR-21 were associated with higher local recurrence (P = 0.025) and mortality (P = 0.029). A logistic regression analysis demonstrated that the relative overexpression of miR-21 (expression > 1) was associated with a 51% reduction in the risk of recurrence. A Cox regression analysis identified miR-21 expression as an independent predictor of survival (P = 0.048); a relative increase in miR-21 expression (>1) was associated with a 50% reduction in the risk of mortality. The expression level of serum miR-21 correlates with the recurrence and mortality of CRC patients. Our results suggest that circulating serum miR-21 is a promising prognostic tumour marker, and they highlight the potential clinical utility of miR-21 expression as a prognostic marker for CRC prognosis.

Studying the association of microRNA‐210 level with chronic hepatitis B progression

We studied the relationship between hypoxia and microRNA-210 (miR-210) levels, the miR-210 levels in patients with hepatitis B and the roles of miR-210 in liver inflammation. We used the concanavalin A (Con A) murine hepatitis model and inflammation, hypoxia and miR-210 levels were examined. In these patients, we studied serum miR-210 levels and clinical indexes related to hepatitis in 90 patients with different stages of chronic hepatitis B and 30 controls. Two functional assays of miR-210 in vitro under hypoxic condition were conducted. The animal experiments indicated that the liver and serum miR-210 levels significantly increased with liver hypoxia and inflammation. In humans, serum miR-210 levels enhanced with hepatitis severity and were related to serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB) and prothrombin activity (PTA) levels. The miR-210 functional assays showed that miR-210 elevation might be related to the decreases in HepG2.2.15 cell dehydrogenase activity and HBV replication under hypoxic conditions. Because the liver inflammation causes liver hypoxia which also results in liver and serum miR-210 level elevation, the serum miR-210 level may serve as a molecular biomarker for the severity of hepatitis and increases in liver miR-210 that we see may be a response of hepatocytes to hypoxia during hepatitis progression.

Circulating microRNA Profiling Identifies a Subset of Metastatic Prostate Cancer Patients with Evidence of Cancer-Associated Hypoxia

MicroRNAs (miRNAs) are small (∼22 nucleotide) non-coding RNAs that regulate a myriad of biological processes and are frequently dysregulated in cancer. Cancer-associated microRNAs have been detected in serum and plasma and hold promise as minimally invasive cancer biomarkers, potentially for assessing disease characteristics in patients with metastatic disease that is difficult to biopsy. Here we used miRNA profiling to identify cancer-associated miRNAs that are differentially expressed in sera from patients with metastatic castration resistant prostate cancer (mCRPC) as compared to healthy controls. Of 365 miRNAs profiled, we identified five serum miRNAs (miR-141, miR-200a, miR-200c, miR-210 and miR-375) that were elevated in cases compared to controls across two independent cohorts. One of these, miR-210, is a known transcriptional target of the hypoxia-responsive HIF-1α signaling pathway. Exposure of cultured prostate cancer cells to hypoxia led to induction of miR-210 and its release into the extracellular environment. Moreover, we found that serum miR-210 levels varied widely amongst mCRPC patients undergoing therapy, and correlated with treatment response as assessed by change in PSA. Our results suggest that (i) cancer-associated hypoxia is a frequent, previously under-appreciated characteristic of mCRPC, and (ii) serum miR-210 may be further developed as a predictive biomarker in patients with this distinct disease biology.

Circulating miR-200c Levels Significantly Predict Response to Chemotherapy and Prognosis of Patients Undergoing Neoadjuvant Chemotherapy for Esophageal Cancer

There is increasing evidence that microRNA expression in cancer tissue is useful for predicting the prognosis of patients with cancer. However, the relationship between the levels of circulating microRNAs and response to chemotherapy and prognosis remains unclear in esophageal cancer. We measured the serum levels of miR-21, miR-145, miR-200c, and let-7c by quantitative RT-PCR in 64 patients with esophageal cancer who underwent neoadjuvant chemotherapy. The serum levels of miR-21, miR-145, miR-200c, and let-7c in esophageal cancer patients were significantly higher than those in healthy volunteers. High expression of miR-200c correlated significantly with poor response to chemotherapy (p = 0.0211). There was no significant relationship between chemosensitivity and the levels of miR-21, miR-145, and let-7c. High expression of miR-200c was associated with shortened progression-free survival (p = 0.0076), but there was no significant relationship between prognosis and the expression of miR-21, miR-145, and let-7c. Multivariate analysis identified miR-200c expression as the most valuable prognostic factor for patients with esophageal cancer who receive neoadjuvant chemotherapy. The serum level of miR-200c can be useful for predicting the response to chemotherapy and the prognosis of patients with esophageal cancer who receive neoadjuvant chemotherapy.

Validation of Circulating miRNA Biomarkers for Predicting Lymph Node Metastasis in Gastric Cancer

We validated candidate biomarkers using circulating miRNAs by analyzing serum miRNA concentrations from patients with gastric cancer (GC) to predict lymph node (LN) metastasis. In a pilot study, serum levels of miR-21, miR-27a, miR-106b, miR-146a, miR-148a, miR-223, and miR-433 were compared in 10 healthy donors, 16 LN-positive patients with GC, and 15 LN-negative patients with GC. Then, we compared the level of three miRNAs (miR-21, miR-146a, and miR-148a) with the total of 79 GC patients with or without LN metastasis. In the pilot study, miR-21, miR-27a, miR-106b, miR-146a, miR-148a, and miR-223 concentrations from LN-positive patients with GC were significantly different from those of LN-negative patients with GC (P < 0.001, P = 0.003, P = 0.033, P < 0.001, P <0.001, and P = 0.017, respectively). In the validation study, levels of miR-21, miR-146a, and miR-148a increased as pN stage increased (P<0.001, P = 0.001, and P < 0.001, respectively). Levels of the miRNAs were significantly different between pN0 and pN0 in the pT1 group (P = 0.013, P = 0.004, and P = 0.035, respectively) and among clinical stages (P = 0.001, P = 0.002, and P < 0.001, respectively). No differences in miRNA levels were observed by pT stage, Lauren's classification, sex, or age. Serum concentrations of miR-21, miR-146a, and miR-148a were closely associated with GC pN stage. These serum miRNA levels could be biomarker candidates to predict the presence of LN metastasis.

Associations between circulating microRNAs (miR-21, miR-34a, miR-122 and miR-451) and non-alcoholic fatty liver

BackgroundIn many industrialized countries, non-alcoholic fatty liver disease (NAFLD) is recognized as an important disease that increases the risk of cardiovascular disease, type-2 diabetes, and metabolic syndrome. Most people with NAFLD are asymptomatic, and the disease is discovered incidentally during clinical laboratory tests. Present screening methods for NAFLD use ultrasound, and CT scans that are time-consuming, and a simple screening method for NAFLD is needed. In this study, we investigated whether serum miRNAs are associated with NAFLD and assessed the potential of serum miRNAs as a biomarker for NAFLD. MethodsWe assessed intrahepatic fat by ultrasound scan, and the serum levels of five miRNAs (miR-21, miR-34a, miR-122, miR-145, and miR-451), which help regulate cholesterol and fatty acid homeostasis in liver tissue, by real-time PCR in a cross-sectional sample of 403 participants who attended health examinations. ResultsSerum levels of miRNAs, miR-21, miR-34a, miR-122, and miR-451 were higher in participants with NAFLD. The serum level of miR-122 was correlated with the severity of liver steatosis. ConclusionSerum levels of miRNAs, particularly miR-122, may be a useful biomarker for NAFLD.