miR-124 Expression Research Articles

Inhibiting essential elements of the DNA methylation pathway negatively impacts the miRNA pathway and fitness of the whitefly Bemisia tabaci

DNA methylation is an epigenetic process that involves the chemical modification of DNA, leading to the regulation of its transcriptional activity. It is primarily known for the addition of methyl groups to cytosine in DNA. The whitefly Bemisia tabaci is a polyphagous pest insect and a vector that is responsible for transmitting numerous plant viruses, resulting in significant economic losses in agricultural crops globally. In our study, we characterized the expression of two key DNA methylation genes, the DNA methyltransferases Dnmt1 and Dnmt3, in B. tabaci. Additionally, we explored the impact of inhibiting DNMTs on the miRNA pathway and fitness of whitefly. To investigate the role of the DNA methylation pathway in B. tabaci, we found that the expression of Dnmt1 and Dnmt3 varied across different tissues and developmental stages of B. tabaci. We employed azacytidine (5-AZA) treatment of adults to inhibit DNMTs (DNMT1 and DNMT3). Administration of 5-AZA affected the survival and reproduction of this pest. Moreover, inhibition of DNMTs led to a decrease in the expression of the miRNA pathway core genes Dicer1 and Argonaute1, which subsequently resulted in reduced expression of Let-7 and miR-184 which are essential microRNAs in the physiology and biology of insects. The study suggests that DNA methyltransferases could be targeted for developing an inhibition strategy to control this pest and vector insect.

Expression of Concern MiR-140 Expression Regulates Cell Proliferation and Targets PD-L1 in NSCLC

Expression of Concern MiR-140 Expression Regulates Cell Proliferation and Targets PD-L1 in NSCLC

Biological functions of LncRNA SNHG14 in the development of thyroid cancer cells via targeting miR-206.

This study aimed to determine lncRNA SNHG14 and miR-206 in Thyroid Cancer ( TC) and to explore the related mechanisms. Sixty-four samples of thyroid tissue were collected from patients with TC. TC cell lines and a normal human thyroid cell line (HTori-3) were bought. lncRNA SNHG14-siRNA (si-lncRNA SNHG14), lncRNA SNHG14-shRNA (sh-lncRNA SNHG14), blank plasmid (siRNA-NC), miR-206-inhibitor, miR-206-mimics were transfected into BHT101 and Ocut-2C cells. qRT-PCR quantified the expression of lncRNA SNHG14 and miR-206, and the expression of vimentin, Snail, N-cadherin, Slug, E-cadherin and ZO-1 proteins were identified via WB. MTT assay, flow cytometry, and Transwell were employed to determine cellular proliferation, apoptosis, and invasion, separately. The high expression of lncRNA SNHG14 and low expression of miR-206 were exhibited in patients with TC. lncRNA SNHG14 and miR-206 were related to lymph node metastases, TNM staging, as well as differentiation of TC. Silencing lncRNA SNHG14 and over-expressing miR-206 inhibited cell EMT, proliferation, and invasion, but accelerated apoptosis. WB demonstrated that silencing lncRNA SNHG14 and over-expressing miR-206 suppressed the expression of Akt, p-ERK1/2, p-p38, p-4EBP1, p-Akt, PI3K, vimentin, Snail, N-cadherin, and Slugn, as well as up-regulated the expression of E-cadherin and ZO-1. Rescue experiment showed that after BHT101 and Ocut-2C cells were transfected with either sh-lncRNA SNHG14+miR-206-mimics or si-lncRNA SNHG14+miR-206-inhibitor, the cellular proliferative, invasive, and apoptotic activities weren't different from those transfected with siRNA-NC. Suppression of lncRNA SNHG14 up-regulates miR-206 and affects EMT, as well as proliferative, invasive, and apoptotic activities of cells, which may become an underlying treatment target for TC.

Expression of Selected miRNAs in Undifferentiated Carcinoma with Osteoclast-like Giant Cells (UCOGC) of the Pancreas: Comparison with Poorly Differentiated Pancreatic Ductal Adenocarcinoma.

Undifferentiated carcinoma with osteoclast-like giant cells (UCOGC) of the pancreas represents a rare subtype of pancreatic ductal adenocarcinoma (PDAC). Despite a distinct morphology and specific clinical behavior, UCOGCs exhibit unexpected similarities in regard to DNA mutational profiles with conventional PDAC. Treating pancreatic ductal adenocarcinoma is particularly challenging, with limited prospects for cure. As with many other malignant neoplasms, the exploration of microRNAs (miRNAs, miRs) in regulating the biological characteristics of pancreatic cancer is undergoing extensive investigation to enhance tumor diagnostics and unveil the therapeutic possibilities. Herein, we evaluated the expression of miR-21, -96, -148a, -155, -196a, -210, and -217 in UCOGCs and poorly differentiated (grade 3, G3) PDACs. The expression of miR-21, miR-155, and miR-210 in both UCOGCs and G3 PDACs was significantly upregulated compared to the levels in normal tissue, while the levels of miR-148a and miR-217 were downregulated. We did not find any significant differences between cancerous and normal tissues for the expression of miR-96 and miR-196a in G3 PDACs, whereas miR-196a was slightly, but significantly, downregulated in UCOGCs. On the other hand, we have not observed significant differences in the expression of the majority of miRNAs between UCOGC and G3 PDAC, with the exception of miR-155. UCOGC samples demonstrated lower mean levels of miR-155 in comparison with those in G3 PDACs.

Role of Micro Ribonucleic Acid-124 in Protecting Against Nerve Injury After Cerebral Ischemia/Reperfusion

The researchers aimed to evaluate micro ribonucleic acid (miR)-124 for its protective role in nerve injury in rats following cerebral ischemia/reperfusion. A focal middle cerebral artery embolism model was constructed. Compared with sham operation group, model and miR-124 NC groups had significantly increased miR-124 expression, neurobehavioral score, malondialdehyde (MDA) content, brain infarct volume, and apoptosis rate, elevated expression levels of Bcl-2- associated X (Bax) protein as well as cleaved caspase-3, 8 and 9, attenuated activity of superoxide dismutase (SOD), and lowered expression of B-cell lymphoma 2 (Bcl-2) (P<0.01). By contrast to those in model and miR-124 NC groups, Bcl- 2 expression rose, miR-124 expression, neurobehavioral score, brain infarct volume percentage and apoptosis rate reduced, Bax, cleaved caspase-3, 8 and 9 expression levels declined, SOD activity enhanced, and MDA content in miR- 124 mimic group dropped (P<0.01). In conclusion, miR-124 protects rats from nerve injury after cerebral ischemia/ reperfusion by improving the antioxidant capacity and regulating the expressions of apoptosis-associated proteins.

MiR-214-PTEN pathway is a potential mechanism for stress-induced immunosuppression affecting chicken immune response to avian influenza virus vaccine

Stress-induced immunosuppression (SIIS) is one of common problems in the intensive poultry industry, affecting the effect of vaccine immunization and leading to high incidences of diseases. In this study, the expression characteristics and regulatory mechanisms of miR-214 in the processes of SIIS and its influence on the immune response to avian influenza virus (AIV) vaccine in chicken were explored. The qRT-PCR results showed that serum circulating miR-214 was significantly differentially expressed (especially on 2, 5, and 28 days post immunization (dpi)) in the processes, so had the potential as a molecular marker. MiR-214 expressions from multiple tissues were closely associated with the changes in circulating miR-214 expression levels. MiR-214-PTEN regulatory network was a potential key regulatory mechanism for the heart, bursa of Fabricius, and glandular stomach to participate in the process of SIIS affecting AIV immune response. This study can provide references for further understanding of stress affecting immune response.

MiR-214 aggravates oxidative stress in thalassemic erythroid cells by targeting ATF4.

Oxidative damage to erythroid cells plays a key role in the pathogenesis of thalassemia. The oxidative stress in thalassemia is potentiated by heme, nonheme iron, and free iron produced by the Fenton reaction, due to degradation of the unstable hemoglobin and iron overload. In addition, the levels of antioxidant enzymes and molecules are significantly decreased in erythrocytes in α- and β-thalassemia. The control of oxidative stress in red blood cells (RBCs) is known to be mediated by microRNAs (miRNAs). In erythroid cells, microR-214 (miR-214) has been reported to respond to external oxidative stress. However, the molecular mechanisms underlying this phenomenon remain unclear, especially during thalassemic erythropoiesis. In the present study, to further understand how miR-214 aggravates oxidative stress in thalassemia erythroid cells, we investigated the molecular mechanism of miR-214 and its regulation of the oxidative status in thalassemia erythrocytes. We have reported a biphasic expression of miR-214 in β- and α-thalassemia. In the present study the effect of miR-214 expression was investigated by using miR -inhibitor and -mimic transfection in erythroid cell lines induced by hemin. Our study showed a biphasic expression of miR-214 in β- and α-thalassemia. Subsequently, we examined the effect of miR-214 on erythroid differentiation in thalassemia. Our study reveals the loss-of-function of miR-214 during translational activation of activating transcription factor 4 mRNA, leading to decreased reactive oxygen species levels and increased glutathione levels in thalassemia erythroid cell. Our results suggest that the expression of activating transcription factor 4 regulated by miR-214 is important for oxidative stress modulation in thalassemic erythroid cells. Our findings can help to better understand the molecular mechanism of miRNA and transcription factors in regulation of oxidative status in erythroid cells, particularly in thalassemia, and could be useful for managing and relieving severe anemia symptoms in patients in the future.

Bioinformatics Study and Experimental Evaluation of miR-182, and miR-34 Expression Profiles in Tuberculosis and Lung Cancer.

Lung cancer is one of the most dangerous cancers and tuberculosis is one of the deadliest infectious diseases in the world. Many studies have confirmed the connection between lung cancer and tuberculosis, and also the microRNAs (miRNAs) that play a major role in the development of these two diseases. This study aims to use different databases to find effective miRNAs and their role in different genes in lung and tuberculosis diseases. It also aims to determine the role of miR-34a and miR-182 in lung cancer and tuberculosis. Using the Gene Expression Omnibus (GEO) database, the influential miRNA databases were studied in the two diseases. Finally, considering bioinformatics results and literature studies, two miR-34a and miR-182 were selected. The role of these miRNAs and their target genes was carefully evaluated using bioinformatics. The expression of miRNAs in the plasma of patients with lung cancer and tuberculosis and healthy individuals was investigated. According to the GEO database, miR-34a and miR-182 are miRNAs that affect tuberculosis and lung cancer. By checking the miRBase, miRcode, DIANA, miRDB, galaxy, Kyoto Encyclopedia of Genes and Genomes databases, the role of these miRNAs on genes and different molecular pathways and their effect on these miRNAs were mentioned. The results of the present study showed that the expression of miR-34a and miR-182 was lower than that of healthy people. The p-value for miR-182 was <0.0001 and for miR-34a was 0.3380. Reducing the expression pattern of these miRNAs indicates their role in lung cancer and tuberculosis occurrence. Therefore, these miRNAs can be used as a biomarker for prognosis, diagnosis, and treatment methods.

Linc01588 deletion inhibits the malignant biological characteristics of hydroquinone-induced leukemic cells via miR-9-5p/SIRT1

Leukemia caused by environmental chemical pollutants has attracted great attention, the malignant leukemic transformation model of TK6 cells induced by hydroquinone (HQ) has been previously found in our team. However, the type of leukemia corresponding to this malignant transformed cell line model needs further study and interpretation. Furthermore, the molecular mechanism of malignant proliferation of leukemic cells induced by HQ remains unclear. This study is the first to reveal the expression of aberrant genes in leukemic cells of HQ-induced malignant transformation, which may correspond to chronic lymphocytic leukemia (CLL). The expression of Linc01588, a long non-coding RNA (lncRNA), was significantly up-regulated in CLL patients and leukemic cell line model which previously described. After gain-of-function assays and loss-of-function assays, feeble cell viability, severe apoptotic phenotype and the increased secretion of TNF-α were easily observed in malignant leukemic TK6 cells with Linc01588 deletion after HQ intervention. The tumors derived from malignant TK6 cells with Linc01588 deletion inoculated subcutaneously in nude mice were smaller than controls. In CLL and its cell line model, the expression of Linc01588 and miR-9–5p, miR-9–5p and SIRT1 were negative correlation respectively in CLL and cell line model, while the expression of Linc01588 and SIRT1 were positive correlation. The dual-luciferase reporter assay showed that Linc01588 & miR-9–5p, miR-9–5p & SIRT1 could bind directly, respectively. Furthermore, knockdown of miR-9–5p successfully rescued the severe apoptotic phenotype and the increased secretion of TNF-α caused by the Linc01588 deletion, the deletion of Linc01588 in human CLL cell line MEC-2 could also inhibit malignant biological characteristics, and the phenotype caused by the deletion of Linc01588 could also be rescued after overexpression of SIRT1. Moreover, the regulation of SIRT1 expression in HQ19 cells by Linc01588 and miR-9–5 P may be related to the Akt/NF-κB pathway. In brief, Linc01588 deletion inhibits the malignant biological characteristics of HQ-induced leukemic cells via miR-9–5p/SIRT1, and it is a novel and hopeful clue for the clinical targeted therapy of CLL.

Exosomal miR-433 regulates the secretion of inflammatory factors in endometrium epithelial cells of dairy cows with endometritis

Endometritis is a common postpartum reproductive system disease, which causes reproductive disorders and even infertility in dairy cows. High-throughput sequencing revealed that exosomal miR-433 is differentially expressed in the peripheral blood of dairy cows with endometritis. However, the specific roles of miR-433 in the occurrence and development of endometritis in dairy cows are still unclear. Therefore, a miR-433-labeled probe was used initially and found that miR-433 is mainly located in uterine cavity epithelial cells and stromal cells. The fluorescence expression of miR-433 in the uterine cavity epithelium and stromal tissues of dairy cows with endometritis is significantly weaker than that in the healthy tissues. The qRT-PCR results showed that the expressions of miR-433 in the uterine tissues of dairy cows with endometritis, LPS stimulated endometrial epithelial cells (EECs), and their derived exosomes were significantly lower than those in the uterine tissues of healthy dairy cows, EECs and their derived exosomes. Exosomal miR-433 derived from EECs transports into neighboring LPS-stimulated EECs by exosome vesicles fusion, regulating the secretion of inflammatory factors within the endometrial epithelium of dairy cows with endometritis, further influencing the development of endometritis. In conclusion, the intensity of miR-433 expression decreased in the epithelial and stromal cells of the uterine lumen and exosomes derived from endometrial epithelium in dairy cows during the occurrence of endometritis, which to some extent promotes the development and progression of endometritis in dairy cows.

ω3-PUFA alleviates neuroinflammation by upregulating miR-107 targeting PIEZO1/NFκB p65

BackgroundMiR-107 is reduced in sepsis and associated with inflammation regulation. Dietary supplementation with polyunsaturated fatty acids (ω3-PUFA) can increase the expression of miR-107; this study investigated whether the ω3-PUFA can effectively inhibit neuroinflammation and improve cognitive function by regulating miR-107 in the brain. MethodsThe LPS-induced mouse model of neuroinflammation and the BV2 cell inflammatory model were used to evaluate the effects of ω3-PUFA on miR-107 expression and inflammation. Intraventricular injection of Agomir and Antagomir was used to modulate miR-107 expression. HE and Nissl staining for analyzing hippocampal neuronal damage, immunofluorescence analysis for glial activation, RT-qPCR, and Western blot were conducted to examine miR-107 expression and inflammation signalling. ResultsThe result shows that LPS successfully induced the mouse neuroinflammation model and BV2 cell inflammation model. Supplementation of ω3-PUFA effectively reduced the secretion of pro-inflammatory factors TNFα, IL1β, and IL6 induced by LPS, improved cognitive function impairment, and increased miR-107 expression in the brain. Overexpression of miR-107 in the brain inhibited the nuclear factor κB (NFκB) pro-inflammatory signalling pathway by targeting PIEZO1, thus suppressing microglial and astrocyte activation and reducing the release of inflammatory mediators, which alleviated neuroinflammatory damage and improved cognitive function in mice. miR-107, as an intron of PANK1, PANK1 is subject to PPAR α Adjust. ω3-PUFA can activate PPARα, but ω3-PUFA upregulates brain miR-107, and PPARα/PANK1-related pathways may not be synchronized, and further research is needed to confirm the specific mechanism by which ω3-PUFA upregulates miR-107. ConclusionThe miR-107/PIEZO1/NFκB p65 pathway represents a novel mechanism underlying the improvement of neuroinflammation by ω3-PUFA.

An integrated ceRNA network identifies miR-375 as an upregulated miRNA playing a tumor suppressive role in aggressive prostate cancer.

Prostate cancer (PCa) remains a significant cause of morbidity and mortality among men worldwide. A number of genes have been implicated in prostate tumorigenesis, but the mechanisms underlying their dysregulation are still incompletely understood. Evidence has established the competing endogenous RNA (ceRNA) theory as a novel regulatory mechanism for post-transcriptional alterations. Yet, a comprehensive characterization of ceRNA network in PCa lacks. Here we utilize stringent in-silico methods to construct a large ceRNA network across different PCa stages, and provide experimental demonstration for the competing regulation among protumorigenic SEC23A, PHTF2, and their corresponding ceRNA pairs. Using machine learning, we establish a ceRNA-based signature (ceRNA_sig) predictive of androgen receptor (AR) activity, tumor aggressiveness, and patient outcomes. Importantly, we identify miR-375 as a key node in PCa ceRNA network, which is upregulated in PCa relative to normal tissues. Forced expression of miR-375 significantly inhibits, while its inhibition promotes, aggressive behaviors of both AR+ and AR- PCa cells in vitro and in vivo. Mechanistically, we show that miR-375 predominantly targets genes possessing oncogenic roles (e.g., proliferation, DNA repair, and metastasis), and thus release targets with tumor suppressive functions. This action model well clarifies why an upregulated miRNA plays a tumor suppressive role in PCa. Together, our study provides new insights into understanding of transcriptomic aberrations during PCa evolution, and nominates miR-375 as a potential therapeutic target for combating aggressive PCa.

Serum microRNA-16 as a potential biomarker for HCV-induced hepato-cellular carcinoma in Egyptian patients

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers in the world. Two risk factors that cause 80–90% of HCC cases globally are chronic infection with hepatitis B virus (HBV) and hepatitis C virus (HCV). The diagnostic value of circulating microRNAs (miRNAs) in numerous tumors has been described. Our research assessed microRNA-16 (miR-16) as a novel biomarker in patients with HCV-induced HCC. The study included three groups. Group 1 included 55 individuals with cirrhosis caused by liver HCV infection in addition to HCC. Group 2 included 55 individuals with cirrhosis brought on by HCV infection. Group 3 included 55 normal control individuals. Expression of miR-16 in blood was assessed by real-time polymerase chain reaction (RT-PCR). The mean level of miR-16 was significantly different in the three groups, with group 1 having the greatest value (1.098 ± 0.647), followed by group 2 (1.1035 ± 0.8567) and group 3 (control subjects) having the lowest value (0.3842 ± 0.21485). The receiver operating characteristic (ROC) curve analysis showed that miR-16 had a higher diagnostic value at area under the curve (AUC) of 0.935 than alpha-feto protein (AUC of 0.859) to differentiate between HCC and control subjects. MiR-16 has a sensitivity of 81.82 % and a specificity of 69.09%, to distinguish between patients with liver cirrhosis and HCC patients. Our findings illustrated that circulating miR-16 can be proposed as a marker for detection of patients with HCV-induced HCC.

Study on attenuation of miR-1-mediated ischemia-induced arrhythmias and infarction in rats by means of fulvning granule

Patients post myocardial infarction (MI) have a high incidence of frequent and complex ventricular arrhythmias. miR-1 is involved in ischemia-induced arrhythmias. Fulvning Granule (FG) is a prescription for treating ischemia-induced arrhythmias. This research investigated therapeutic effect of FG on ischemia-induced arrhythmias in an depth way, focusing on expression of miR-1. 60 healthy Sprague Dawly rats were assigned to operation group, MI+normal saline group, MI+low dose of FG group, MI+moderate dose of FG group and MI+high dose of FG group, MI+propranolol group and MI+moderate dose of FG+propranolol group. Hemodynamic measurement, arrhythmia classification, infarct area evaluation and miR-1 level quantification with expression of PKA and SRF were adopted 4 weeks after operation. FG improved hemodynamic indexes and inhibited expression of miR-1. The optimal dose of FG was medium (P < 0.05). Combination of FG and propranolol further improved the hemodynamics indexes and inhibited the expression of miR-1, PKA and SRF (P < 0.05). FG regulated miR-1 expression via inhibition of Protein Kinase A (PKA) and serum response factor (SRF) expressions. Meanwhile, β-adrenoceptor/PKA signaling pathway played a role in regulating miR-1 expression, while Fulvning granule combined with propranolol and showed an antiarrhythmic role and improved cardiac function after myocardial infarction.

Fludrocortisone improves endometrial receptivity by regulating expression of ENaC, SGK1, HAND2, miR-200a, miR-145, miR-451, mTOR, and 4E-BP1 during the implantation window in mice

Fludrocortisone improves endometrial receptivity by regulating expression of ENaC, SGK1, HAND2, miR-200a, miR-145, miR-451, mTOR, and 4E-BP1 during the implantation window in mice

Low expression of miR-182 caused by DNA hypermethylation accelerates acute lymphocyte leukemia development by targeting PBX3 and BCL2: miR-182 promoter methylation is a predictive marker for hypomethylation agents + BCL2 inhibitor venetoclax

BackgroundmiR-182 promoter hypermethylation frequently occurs in various tumors, including acute myeloid leukemia, and leads to low expression of miR-182. However, whether adult acute lymphocyte leukemia (ALL) cells have high miR-182 promoter methylation has not been determined.MethodsTo assess the methylation status of the miR-182 promoter, methylation and unmethylation-specific PCR analysis, bisulfite-sequencing analysis, and MethylTarget™ assays were performed to measure the frequency of methylation at the miR-182 promoter. Bone marrow cells were isolated from miR-182 knockout (182KO) and 182 wild type (182WT) mice to construct BCR-ABL (P190) and Notch-induced murine B-ALL and T-ALL models, respectively. Primary ALL samples were performed to investigate synergistic effects of the hypomethylation agents (HMAs) and the BCL2 inhibitor venetoclax (Ven) in vitro.ResultsmiR-182 (miR-182-5P) expression was substantially lower in ALL blasts than in normal controls (NCs) because of DNA hypermethylation at the miR-182 promoter in ALL blasts but not in normal controls (NCs). Knockout of miR-182 (182KO) markedly accelerated ALL development, facilitated the infiltration, and shortened the OS in a BCR-ABL (P190)-induced murine B-ALL model. Furthermore, the 182KO ALL cell population was enriched with more leukemia-initiating cells (CD43+B220+ cells, LICs) and presented higher leukemogenic activity than the 182WT ALL population. Furthermore, depletion of miR-182 reduced the OS in a Notch-induced murine T-ALL model, suggesting that miR-182 knockout accelerates ALL development. Mechanistically, overexpression of miR-182 inhibited proliferation and induced apoptosis by directly targeting PBX3 and BCL2, two well-known oncogenes, that are key targets of miR-182. Most importantly, DAC in combination with Ven had synergistic effects on ALL cells with miR-182 promoter hypermethylation, but not on ALL cells with miR-182 promoter hypomethylation.ConclusionsCollectively, we identified miR-182 as a tumor suppressor gene in ALL cells and low expression of miR-182 because of hypermethylation facilitates the malignant phenotype of ALL cells. DAC + Ven cotreatment might has been applied in the clinical try for ALL patients with miR-182 promoter hypermethylation. Furthermore, the methylation frequency at the miR-182 promoter should be a potential biomarker for DAC + Ven treatment in ALL patients.

MicroRNA-124 influenced depressive symptoms via large-scale brain connectivity in major depressive disorder patients

This study aimed to investigate the neurobiological mechanisms by which microRNA 124 (miR-124) is involved in major depressive disorder (MDD). We enrolled 53 untreated MDD patients and 38 healthy control (HC) subjects who completed behavior assessments and resting-state functional MRI (rs-fMRI) scans. MiR-124 expression levels were detected in the peripheral blood of all participants. We determined that miR-124 levels could influence depressive symptoms via disrupted large-scale intrinsic intra- and internetwork connectivity, including the default mode network (DMN)-DMN, dorsal attention network (DAN)-salience network (SN), and DAN-cingulo-opercular network (CON). This study deepens our understanding of how miR-124 dysregulation contributes to depression.

Abstract 2999: Evaluation of microRNA expression in metastatic and non-metastatic salivary gland mucoepidermoid carcinoma

Abstract Salivary gland tumors are a heterogeneous group of lesions, being mucoepidermoid carcinoma (MEC) the malignant neoplasm with the highest incidence, occurring mainly in the parotid gland. Characterization of its histological grade (high, intermediate, and low) is important for determining patient prognosis. Metastasis is more common high-grade tumors and can occur at regional lymph nodes or distant sites. Although the mechanisms underlying the metastatic process are largely unknown, large-scale microRNA expression profiling studies of human cancers have demonstrated that dysregulation of miRNA is frequently associated with many cancer types. The aim of this study is to validate the use of microRNA expression for the discrimination of the metastatic potential of MEC samples. Using Real Time RT-PCR (qPCR) we have analyzed the expression of 384 miRNAs and controls in 4 non-metastatic MECs, 3 MECs with lymph node metastasis, 3 MECs with distant metastasis, and 2 non-neoplastic human salivary gland samples. Comparing the expression among these groups we identified 45 differentially expressed miRNAs that may be related with the metastatic potential of these tumors. To validate the microRNA expression associated with the metastatic potential, we selected 7 out of the 45 differentially expressed microRNAs and 7 MEC samples from the different groups of samples. Considering the 7 microRNAs evaluated, we validated that the expression of miR-191 was increased in non-neoplastic samples when compared to MECs with lymph node metastasis and the expression of miR-494 was increased in non-neoplastic samples when compared to MECs with distant metastasis, suggesting that loss of these microRNAs might be involved in the development of metastasis in mucoepidermoid carcinoma. The determination of a miRNA expression profile could provide a better understanding of the molecular basis of MEC and facilitate the determination of diagnosis and prognosis of patients. Citation Format: Maria E. Trevizani, Katia K. Oliveira, Fabio A. Marchi, Daniela Bizinelli, Fernanda V. Mariano, Cibele P. Nagano, Felipe A. Costa, Clovis A. Pinto, Luiz P. Kowalski, Silvia V. Lourenço, Cláudia M. Coutinho-Camillo. Evaluation of microRNA expression in metastatic and non-metastatic salivary gland mucoepidermoid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2999.

Abstract 2989: MicroRNA profiling in human samples and cell lines uncovers eight key players in the cisplain resistance of HGSOC

Abstract Metastasis and drug resistance remain significant contributors to cancer-related mortality globally. In ovarian cancer, a substantial 70% of cases develop resistance to the front-line therapy, cisplatin. Despite numerous proposed mechanisms for cisplatin resistance, the complete molecular events leading to this phenomenon in ovarian cancer remain incompletely understood. Mounting evidence suggests that dysregulation of microRNAs (miRNAs) plays a pivotal role in carcinogenesis, including the development of drug resistance. While various miRNAs have been identified in ovarian cancer samples and cell lines, few studies have compared miRNA expression in human paraffin ovarian samples and cisplatin-resistant high-grade serous ovarian cancer (HGSOC), the most prevalent and malignant of gynecological malignancies. This study aimed to identify key miRNAs implicated in cisplatin resistance. We performed miRNA expression profiles in RNA isolated from human paraffin ovarian tumors and ovarian cancers cell lines. Eight miRNAs were commonly increased in paraffin samples and cisplatin resistant ovarian cancer cells. Targeting these miRNAs with inhibitors significantly reduced cell proliferation by more than 50% for miR-203a, miR-96-5p, miR-10a-5p, miR-141-3p, miR-200c-3p, and miR-182-5p, and to a lesser extent, miR-296-5p and miR-1206. Inhibitors demonstrated a reduction in cell migration for all targets except miR-200c-3p and miR-10a-5p. Analysis of online databases, literature reports, and molecular pathway construction revealed that these eight miRNAs regulate key molecular pathways associated with cell proliferation, primarily through PTEN regulation in cisplatin-resistant HGSOC cells. Interrogation of the KM plotter patient database revealed that high expression of miR-1206, miR-10a, miR-141, and miR-96 correlates with a poor prognosis in ovarian cancer patients. These findings position these eight miRNAs as potential therapeutic targets and markers for cisplatin response in ovarian cancer therapy. Citation Format: Mariela Rivera-Serrano, Marienid Flores, Jose Rolon, Victor Reyes, Fatma Valiyeva, Pablo E. Vivas-Mejia. MicroRNA profiling in human samples and cell lines uncovers eight key players in the cisplain resistance of HGSOC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2989.

Abstract 3624: A low-cost kit for gentle, effective and timely extracellular vesicle (GET EVs) isolation: Accelerating development of RNA-based liquid biopsies for neuroendocrine neoplasms

Abstract Extracellular vesicles (EVs) are cell fragments released by all cells, making them promising platforms for cancer biomarker development. Effective isolation of ultra-pure EVs for downstream analyses is key for EV-based liquid biopsy development. However, current EV isolation methods such as ultracentrifugation (UC) and other commercialized EV isolation kits are lackluster because of damage to EVs, length of time required, and low EV recovery rates. In response, we developed an “GET EV” kit which is based on the principles of lipid energy states, also known as the aqueous two-phase system (ATPS) to isolate EVs from any media. Nanoscale flow cytometry (nFC) analysis revealed that ATPS has greater EV enrichment capability (21.4 × vs. 10.9 × times fold enrichment) and higher EV recovery efficiency (97.6% vs. 69.3% recovery) than UC. Other EV isolation kits were tested and were inferior to ATPS in terms of EV recovery and EV-RNA recovery. EV subpopulations as determined by EV biomarkers (CD9, CD63, CD81, etc.) were confirmed by nFC. “Omics” studies (small RNA sequencing and proteomics) also confirmed the presence of expected EV markers. We developed an RNA-based liquid biopsy for Neuroendocrine Neoplasms (NENs) by quantitating the presence of EVs containing miR-375, an established biomarker for NENs. Using the GET EVs kit, we isolated EVs from healthy volunteer and patient plasma samples of NEN patients. RT-qPCR demonstrated enriched expression of miR-375 in EVs isolated from Lung and GI NEN patient plasma samples. Our study establishes the use of GET EV kits to efficiently, rapidly, and gently isolate EVs from small plasma samples (250 uL). This is a low-cost innovation that will finally enable the development of other RNA-based Liquid Biopsies for other disease sites with significant diagnostic and prognostic implications. Citation Format: Boyang Su, Morteza Jeyhani, Xiaojing Yang, Jina Nanayakkara, Reese Wunsche, Neil Renwich, Scott Tsai, Hon Leong. A low-cost kit for gentle, effective and timely extracellular vesicle (GET EVs) isolation: Accelerating development of RNA-based liquid biopsies for neuroendocrine neoplasms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3624.