Project description:MicroRNAs (miRNA) are short non-coding RNAs widely implicated in development, gene regulation, and disease progression. Most miRNAs utilize the RNase III enzymes Drosha and Dicer for biogenesis in animals. One notable exception is the RNA polymerase II transcription start sites (TSS) miRNAs whose biogenesis requires Dicer but not Drosha. The functional importance of the TSS-miRNA biogenesis pathway has remained uncertain due to their unelucidated targetomes. To better understand the function of TSS-miRNAs, we applied a modified Crosslinking, Ligation, and Sequencing of Hybrids on Argonaute (Ago-qCLASH) to identify the targets for TSS-miRNAs in HCT116 colorectal cancer cells with or without Drosha knockout (KO). We observed that miR-320a hybrids dominate in TSS-miRNA hybrids identified by Ago-qCLASH. Targets for miR-320a are enriched in the eIF2 signaling pathway, a downstream component of the unfolded protein response. Consistently, in miR-320a mimic- and inhibitor- transfected cells, differentially expressed genes are enriched in the eIF2 signaling pathway. Within the Ago-qCLASH data, we identified the endoplasmic reticulum (ER) chaperone Calnexin as a direct miR-320a target, thus connecting miR-320a to the unfolded protein response. During ER stress, but not amino acid deprivation, miR-320a up-regulates ATF4, a critical transcription factor for resolving ER stress. Our study helps to elucidate the targetome of the TSS-miRNAs in colorectal cancer cells and establishes miR-320a as a regulator of unfolded protein response.
Project description:In this study we present an experimental pipeline that takes into consideration sample collection, processing, enrichment, and the subsequent comparative analysis of circulating small ribonucleic acids using small RNA sequencing and RT-qPCR. Initially, a panel of miRNAs dysregulated in circulating blood from breast cancer patients compared to healthy women were identified using small RNA sequencing. MiR-320a was identified as the most dysregulated miRNA between the two female cohorts. Total RNA and enriched small RNA populations (<30 bp) isolated from peripheral blood from the same female cohort samples were then tested using a miR-320a RT-qPCR assay. When total RNA was analyzed with this miR-320a RT-qPCR assay, a 2.3-fold decrease in expression levels was observed between blood samples from healthy controls and breast cancer patients. However, upon enrichment for the small RNA population and subsequent analysis of miR-320a using RT-qPCR, its dysregulation in breast cancer patients was more pronounced with an 8.89-fold decrease in miR-320a expression.
Project description:Analysis of gene expression of primary osteoblasts transfected with miR-320a mimic or miR-320a inhibitor or their respective controls.
Project description:Purpose: In this study, we performed RNA-seq analysis as a screening strategy to identify EV-miRNAs derived from serum of well clinically annotated breast cancer (BC) patients from South of Brazil. Methods: EVs from three groups of samples, healthy controls (CT), luminal A (LA), and triple negative (TNBC), were isolated from serum using a precipitation method and analyzed by RNA-seq (screening phase). Subsequently, four EV-miRNAs (miR-142-5p, miR-150-5p, miR-320a, and miR-4433b-5p) were selected to be quantified by RT-qPCR in individual samples (test phase). Results: A panel composed of miR-142-5p, miR-320a, and miR-4433b-5p discriminated BC patients from CT with an AUC of 0.8387 (93.33% sensitivity, 68.75% specificity). In addition, the combination of miR-142-5p and miR-320a, presented an AUC of 0.941 (100% sensitivity, 93.80% specificity) in distinguishing LA patients from CT. Interestingly, decrease expression of miR-142-5p and miR-150-5p were significantly associated with more advanced tumor grades (grade III), while the decrease expression of miR-142-5p and miR-320a with larger tumor size. Conclusion: These results provide insights into the potential application of EVs-miRNAs from serum as novel specific markers for early diagnosis of BC.
Project description:In this study we present an experimental pipeline that takes into consideration sample collection, processing, enrichment, and the subsequent comparative analysis of circulating small ribonucleic acids using small RNA sequencing and RT-qPCR. Initially, a panel of miRNAs dysregulated in circulating blood from breast cancer patients compared to healthy women were identified using small RNA sequencing. MiR-320a was identified as the most dysregulated miRNA between the two female cohorts. Total RNA and enriched small RNA populations (<30 bp) isolated from peripheral blood from the same female cohort samples were then tested using a miR-320a RT-qPCR assay. When total RNA was analyzed with this miR-320a RT-qPCR assay, a 2.3-fold decrease in expression levels was observed between blood samples from healthy controls and breast cancer patients. However, upon enrichment for the small RNA population and subsequent analysis of miR-320a using RT-qPCR, its dysregulation in breast cancer patients was more pronounced with an 8.89-fold decrease in miR-320a expression. miRNAseq with Illumina 2000 of human females n=23 controls and n=14 cases [Ethics Statement] Written informed consent was received from all participants in the study. Ethical approval was granted by the Clinical Research Ethics Committee, Galway University Hospital.
Project description:Cervical cancer is a malignant disease that causes around 350 000 deaths annually. One of the essential things in enhancing the survival rates of cervical cancer is the availability of high-quality, sensitive, and specific diagnostic tests capturing the early stages of the disease. In this study, we analyzed the differential expression of microRNA in cervical cancer FFPE tissue samples. The comprehensive miRNA expression profile was detected using modern small-RNA sequencing technology, and the results were validated by real-time PCR. The relative expression of selected miRNAs was determined using the 2-ΔΔCt method. Moreover, two strategies for endogenous control selection were compared. miRNA profiling by small-RNA sequencing and a commercially supplied microfluidic card with 30recommended endogenous controls predesigned by the manufacturer. The RefFinder algorithm and coefficient of variation were used for endogenous control selection. A combination of miR-181a-5p and miR-423-3p was chosen as the most optimal normalizer. Statistically significant upregulation ofmiR-320a-3p, miR-7704, and downregulation of miR-26a-5p was detected, so we propose the combination as a new potential miRNA cervical cancer diagnostic panel. Using ROC curve analysis, the proposed panel showed 93.33% specificity and 96.97% sensitivity with AUC = 0.985. Inconclusion, our study suggests an optimal combination of two endogenous miRNAs for data normalization of miRNA expression studies in the cervical tissue (miR-181a-5p and miR-423-3p) and a novel diagnostic marker panel of three miRNAs (miR-320a-3p, miR-7704, miR-26a-5p) for cervical cancer.
Project description:Purpose: Preoperative 5-fluorouracil (5-FU) based radiochemotherapy (RCT) represents the standard treatment for locally advanced rectal cancer. Both, tumor response and progression vary considerably. MicroRNAs represent master regulators of gene expression, and may therefore contribute to this heterogeneity. Results: Thirty-six miRNAs were identified to significantly correlate with sensitivity of CRC cell lines to RCT (q < 0.05). This list included miR320a as most significantly correlated as well as other miRNAs involved in the MAPK-, TGF- and Wnt-pathway. Importantly, transfection of selected miRNAs (let7g, miR-132, miR-224, miR-320a and miR-429) each induced a shift of sensitivity (p<0.00001). Moreover, high expression of miR-224 was associated with a poor prognosis in rectal cancer patients (p=0.043).
Project description:microRNAs (miRNAs) are small non-coding RNAs that function in literally all cellular processes. miRNAs interact with Argonaute (Ago) proteins and guide them to specific target sites located in the 3’ untranslated region (UTR) of target mRNAs leading to translational repression and deadenylation-induced mRNA degradation. Most miRNAs are processed from hairpin-structured precursors by the consecutive action of the RNase III enzymes Drosha and Dicer. However, processing of miR-451 is Dicer-independent and cleavage is mediated by the endonuclease Ago2. Here we have characterized miR-451 sequence and structure requirements for processing as well as sorting of miRNAs into different Ago proteins. Pre-miR-451 appears to be optimized for Ago2 cleavage and changes result in reduced processing. In addition, we show that the mature miR-451 only associates with Ago2 suggesting that mature miRNAs are not exchanged between different members of the Ago protein family. Based on cloning and deep sequencing of endogenous miRNAs associated with Ago1-3, we do not find evidence for miRNA sorting in human cells. However, Ago identity appears to influence the length of some miRNAs, while others remain unaffected.