microRNA Expression In Whole Blood Research Articles

Platelet Function and Maturity and Related microRNA Expression in Whole Blood in Patients with ST-Segment Elevation Myocardial Infarction.

Reduced effect of antiplatelet therapy has been reported in patients with ST-segment elevation myocardial infarction (STEMI). MicroRNAs (miRs) may influence platelet function and maturity, and subsequently the effect of antiplatelet therapy. We aimed to explore the association between miR expression and platelet function and maturity in patients with acute STEMI and healthy individuals. We performed an observational study of STEMI patients admitted directly to primary percutaneous coronary intervention. Patients were treated with antiplatelet therapy according to guidelines. Within 24 hours after admission, blood samples were obtained to measure: the expression of 10 candidate miRs, platelet function markers using advanced flow cytometry, platelet aggregation, serum thromboxane B2, and platelet maturity markers. Furthermore, blood samples from healthy individuals were obtained to determine the normal variation. In total, 61 STEMI patients and 50 healthy individuals were included. STEMI patients had higher expression of miR-21-5p, miR-26b-5p, and miR-223-3p and lower expression of miR-150-5p, miR423-5p, and miR-1180-3p than healthy individuals. In STEMI patients, the expression of miR-26b-5p showed the most consistent association with platelet function (all p-values <0.05, Spearman's rho ranging from 0.27 to 0.41), while the expression of miR-150-5p and miR-223-3p showed negative associations with platelet function. No association between miR expression and platelet maturity markers was observed. In patients with STEMI, the expression of six miRs was significantly different from healthy individuals. The expression of miR-26b-5p may affect platelet function in acute STEMI patients and potentially influence the effect of antiplatelet therapy.

American Heart Association Cardiovascular Genome-Phenome Study: foundational basis and program.

The American Heart Association has established the Cardiovascular Genome-Phenome Study (CV-GPS) as a means by which to achieve the goal of using modern genomics and phenotyping optimally to combat cardiovascular disease (CVD). CVD remains the leading cause of death in the United States and has become a major cause of morbidity and mortality worldwide. The course of CVD begins at an early age and evolves throughout life. Typically, risk factor precursors (eg, prehypertension, borderline abnormal lipids) are first observed in adolescence or young adulthood. By middle age, they develop into full-fledged cardiometabolic risk factors and subclinical disease, which usually become clinically apparent in older age. Importantly, risk factors for CVD reflect the complex interplay between genetic and environmental factors and demonstrate the complexity of the multiple determinants of disease. Editorial see p 17 Many of the genetic and environmental determinants of CVD have been identified over the past 50 years, and successful preventive and therapeutic strategies have been developed as a result. However, many potential genetic or acquired disease drivers remain unaccounted for, as illustrated by the observation that the major CVD risk factors combined account for only a fraction of the population-attributable risk.1 In addition, variations in CVD risk exist among individuals with similar risk profiles. Part of these differences may reflect differences in profiles of known risk factors that have not yet been fully refined but also individual differences in underlying genetic modifiers of such risk factors. Modern genomics, with its ability to provide ideally unbiased analysis of the entire genome, offers an approach to the ascertainment of all genetic determinants of CVD. Furthermore, the increasingly broad range of “omics” methods, including RNA-Seq, modern proteomics, metabolomics, and metabonomics, provide deeper and more refined molecular detail by which to define an individual’s genome and its relationship to (patho)phenotype. …

MicroRNA Biomarkers in Whole Blood for Detection of Pancreatic Cancer

Biomarkers for the early diagnosis of patients with pancreatic cancer are needed to improve prognosis. To describe differences in microRNA expression in whole blood between patients with pancreatic cancer, chronic pancreatitis, and healthy participants and to identify panels of microRNAs for use in diagnosis of pancreatic cancer compared with the cancer antigen 19-9 (CA19-9). A case-control study that included 409 patients with pancreatic cancer and 25 with chronic pancreatitis who had been included prospectively in the Danish BIOPAC (Biomarkers in Patients with Pancreatic Cancer) study (July 2008-October 2012) plus 312 blood donors as healthy participants. The microRNA expressions in pretreatment whole blood RNA samples were collected and analyzed in 3 randomly determined subcohorts: discovery cohort (143 patients with pancreatic cancer, 18 patients with chronic pancreatitis, and 69 healthy participants), training cohort (180 patients with pancreatic cancer, 1 patient with chronic pancreatitis, and 199 healthy participants), and validation cohort (86 patients with pancreatic cancer, 7 patients with chronic pancreatitis, and 44 healthy participants); 754 microRNAs were screened in the discovery cohort and 38 microRNAs in the training cohort and 13 microRNAs in the validation cohort. Identification of microRNA panels (classifiers) for diagnosing pancreatic cancer. The discovery cohort demonstrated that 38 microRNAs in whole blood were significantly dysregulated in patients with pancreatic cancer compared with controls. These microRNAs were tested in the training cohort and 2 diagnostic panels were constructed comprising 4 microRNAs in index I (miR-145, miR-150, miR-223, miR-636) and 10 in index II (miR-26b, miR-34a, miR-122, miR-126*, miR-145, miR-150, miR-223, miR-505, miR-636, miR-885.5p). The test characteristics for the training cohort were index I area under the curve (AUC) of 0.86 (95% CI, 0.82-0.90), sensitivity of 0.85 (95% CI, 0.79-0.90), and specificity of 0.64 (95% CI, 0.57-0.71); index II AUC of 0.93 (95% CI, 0.90-0.96), sensitivity of 0.85 (95% CI, 0.79-0.90), and specificity of 0.85 (95% CI, 0.80-0.85); and CA19-9 AUC of 0.90 (95% CI, 0.87-0.94), sensitivity of 0.86 (95% CI, 0.80-0.90), and specificity of 0.99 (95% CI, 0.96-1.00). Performances were strengthened in the validation cohort by combining panels and CA19-9 (index I AUC of 0.94 [95% CI, 0.90-0.98] and index II AUC of 0.93 [95% CI, 0.89-0.97]). Compared with CA19-9 alone, the AUC for the combination of index I and CA19-9 was significantly higher (P = .01). The performance of the panels in patients with stage IA-IIB pancreatic cancer was index I AUC of 0.80 (95% CI, 0.73-0.87); index I and CA19-9 AUC of 0.83 (95% CI, 0.76-0.90); index II AUC of 0.91 (95% CI, 0.87-0.94); and index II and CA19-9 AUC of 0.91 (95% CI, 0.86-0.95). This study identified 2 diagnostic panels based on microRNA expression in whole blood with the potential to distinguish patients with pancreatic cancer from healthy controls. Further research is necessary to understand whether these have clinical implications for early detection of pancreatic cancer and how much this information adds to serum CA19-9.

Prediction of survival in patients with metastatic colorectal cancer treated with third-line cetuximab and irinotecan through changes in microRNA expression in whole blood during treatment

3532 Background: MicroRNAs (miRNAs) have shown potential as predictive markers for disease outcome in patients with cancer. MiRNA profiling in whole blood from patients with metastatic colorectal cancer (CRC) before and during treatment was performed to identify a panel of deregulated miRNAs and changes in miRNA expression over time that could predict overall survival (OS). Methods: A total of 144 patients with metastatic CRC included in a prospective phase II study of third-line treatment with cetuximab and irinotecan every second week were studied. MiRNAs before and during treatment were isolated from whole blood collected in PAXgene Blood RNA tubes (Qiagen), and miRNA profiling was performed using TaqMan MicroRNA Array v2.0 (Applied Biosystems). The Cox proportional hazard (CPH) model was applied to study the absolute effect of miRNA expression on OS. Each miRNA expression for every measurement was included as a time varying covariate and each miRNA effect on OS was tested. All miRNA that met the 0.001 significance level was then included in a multivariate CPH model. Second, we studied the effect of miRNA change over time by calculating relative changes in miRNA for patients with at least two miRNAs (n=105). Results: At time of follow-up 132 (92%) of the patients were dead. High expression of miR-361-5p and miR-597, and low expression of miR-31, miR324-3p, let-7e and miR-24 predicted OS after controlling for KRAS mutation status, performance status, age and gender. Hazard ratios (HR) and 95% confidence interval (CI) were miR-31 (0.72; 0.55-0.94), miR-361-5p (2.01; 1.33-3.03), miR-597 (1.70; 1.27-2.27), miR324-3p (0.47; 0.31-0.70), let-7e (0.63; 0.44-0.90) and miR-24 (0.66; 0.44-0.99). During treatment, relative changes in miRNA expression for miR-31 (0.77; 0.62-0.95), let-7g (0.62; 0.43-0.89) and miR-424 (1.38; 1.08-1.76) predicted OS. Conclusions: We identified 6 miRNAs that may be good biomarkers of value for OS in patients with metastatic CRC treated with cetuximab and irinotecan. MiR-31 was a predictor for OS at any time point during treatment, and relative change in miR-31 expression during treatment was a predictor for OS.

The Genomic Analysis of Erythrocyte microRNA Expression in Sickle Cell Diseases

BackgroundSince mature erythrocytes are terminally differentiated cells without nuclei and organelles, it is commonly thought that they do not contain nucleic acids. In this study, we have re-examined this issue by analyzing the transcriptome of a purified population of human mature erythrocytes from individuals with normal hemoglobin (HbAA) and homozygous sickle cell disease (HbSS).Methods and FindingsUsing a combination of microarray analysis, real-time RT-PCR and Northern blots, we found that mature erythrocytes, while lacking ribosomal and large-sized RNAs, contain abundant and diverse microRNAs. MicroRNA expression of erythrocytes was different from that of reticulocytes and leukocytes, and contributed the majority of the microRNA expression in whole blood. When we used microRNA microarrays to analyze erythrocytes from HbAA and HbSS individuals, we noted a dramatic difference in their microRNA expression pattern. We found that miR-320 played an important role for the down-regulation of its target gene, CD71 during reticulocyte terminal differentiation. Further investigation revealed that poor expression of miR-320 in HbSS cells was associated with their defective downregulation CD71 during terminal differentiation.ConclusionsIn summary, we have discovered significant microRNA expression in human mature erythrocytes, which is dramatically altered in HbSS erythrocytes and their defect in terminal differentiation. Thus, the global analysis of microRNA expression in circulating erythrocytes can provide mechanistic insights into the disease phenotypes of erythrocyte diseases.

The Identification and Genomic Analysis of microRNAs in Human Erythrocytes in Sickle Cell Diseases.

Erythrocytes are circulating blood cells responsible for efficient gas exchange in human body. Since mature erythrocytes are terminally differentiated cells without nuclei and organelles, it is commonly thought that they do not contain nucleic acids. In this study, we re-examined this issue and found that human mature erythrocytes, while lacking ribosomal and large-sized RNAs, possess abundant small-sized RNAs. Using a combination of microarray analysis, real-time RT-PCR and Northern blots we found that mature erythrocytes contained abundant and diverse microRNAs which were distinct from microRNAs observed in reticulocytes/leukocytes and contributed to the majority of the microRNA expression in whole blood. When we used microarrays to analyze erythrocytes from normal (HbAA) and homozygous sickle (HbSS) individulas, we noted dramatic a difference in their microRNA expression pattern. To investigate how this difference is associated with erythrocyte disease phenotypes, we found that the poor expression of miR-320 was responsible for the defective downregulation of its target gene CD71 in HbSS cells during terminal differentiation. Collectively, we have discovered significant microRNA expression in human mature erythrocytes, which enables the microarray analysis of erythrocyte property to provide insights into the human erythrocyte diseases.