Restoring microRNA-34a overcomes acquired drug resistance and disease progression in human breast cancer cell lines via suppressing the ABCC1 gene.

PURPOSE: Breast cancer is one of the leading types of cancer diagnosed in women. Despite the improvements in chemotherapeutic cure strategies, drug resistance is still an obstacle leading to disease aggressiveness. The small non-coding RNA molecules, miRNAs, have been implicated recently to be involved as regulators of gene expression through the silencing of mRNA targets that contributed to several cellular processes related to cancer metastasis. Hence, the present study aimed to investigate the beneficial role and mechanism of miRNA-34a-based gene therapy as a novel approach for conquering drug resistance mediated by ATP-binding cassette (ABC) transporters in breast cancer cells, besides exploring the associated invasive behaviors. MATERIAL AND METHODS: Bioinformatics tools were used to predict miRNA ABC transporter targets by tracking the ABC transporter pathway. After the establishment of drug-resistant breast cancer MCF-7 and MDA-MB-231 sublines, cells were transfected with the mimic or inhibitor of miRNA-34a-5p. The quantitative expression of genes involved in drug resistance was performed by QRT-PCR, and the exact ABC transporter target specification interaction was confirmed by dual-luciferase reporter assay. Furthermore, flow cytometric analysis was utilized to determine the ability of miRNA-34a-treated cells against doxorubicin uptake and accumulation in cell cycle phases. The spreading capability was examined by colony formation, migration, and wound healing assays. The apoptotic activity was estimated as well. RESULTS: Our findings firstly discovered the mechanism of miRNA-34a-5p restoration as an anti-drug-resistant molecule that highly significantly attenuates the expression of ABCC1 via the direct targeting of its 3'- untranslated regions in resistant breast cancer cell lines, with a significant increase of doxorubicin influx by MDA-MB-231/Dox-resistant cells. Additionally, the current data validated a significant reduction of metastatic potentials upon miRNA-34a-5p upregulation in both types of breast cancer-resistant cells. CONCLUSION: The ectopic expression of miRNA-34a ameliorates the acquired drug resistance and the migration properties that may eventually lead to improved clinical strategies and outcomes for breast cancer patients. Additionally, miRNA-34a could be monitored as a diagnostic/prognostic biomarker for resistant conditions.

In Silico and In Vivo Evaluation of microRNA-181c-5p's Role in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a fatal disease, accounting for 75-85% of primary liver cancers. The conclusive research on miR-181c-5p's role in hepatocarcinogenesis, whether it has oncogenic effects or acts as a tumor repressor, is limited and fluctuating. Therefore, the current study aimed to elucidate the role of miR-181c-5p in HCC in silico and in vivo. The bioinformatics analysis of miR-181c-5p expression data in HCC using several databases strongly shed light on its involvement in HCC development, but also confirmed the fluctuating data around its role. miR-181c-5p was proven here to have an oncogenic role by increasing HepG2 cells' viability as confirmed by MTT analysis. In addition, miR-181c-5p was upregulated in the HCC positive control group and progressed the HCC development and malignant features by its forced expression in an HCC mouse model by targeted delivery using a LA-PAMAM polyplex. This is indicated by the cancerous gross and histological features, and the significant increase in liver function biomarkers. The functional enrichment bioinformatics analyses of miR-181c-5p-downregulated targets in HCC indicated that miR-181c-5p targets were significantly enriched in multiple pathways and biological processes involved in HCC development. Fbxl3, an example for miR-181c-5p potential targets, downregulation and its correlation with miR-181c-5p were validated by qPCR. In conclusion, miR-181c-5p is upregulated in HCC and has an oncogenic role enhancing HCC progression.

The anti-androgenic effect of quercetin on hyperandrogenism and ovarian dysfunction induced in a dehydroepiandrosterone rat model of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a multi-factorial endocrine disorder associated with hyperandrogenism. Dehydroepiandrosterone (DHEA) administration to prepubertal rats stimulates androgen biosynthesis and generation of the PCOS model. The present study aimed to evaluate the anti-androgenic effects of quercetin (Q) in comparison with metformin (MET) on hyperandrogenism and ovarian dysfunction in a DHEA-induced PCOS rat model. After induction of PCOS, female rats were allocated into six groups with 7 rats in each group: normal control; PCOS (DHEA), MET (25 mg/kg, oral administration), Q (25 mg/kg, oral administration), DHEA + MET (25 mg/kg, oral administration), and DHEA + Q (25 mg/kg, oral administration) for 28 days. MET and Q individually reduced body weight, serum free testosterone (T) and luteinizing hormone (LH), and LH/follicle-stimulating hormone (FSH) ratio in the PCOS rats. Both treatments elevated estradiol (E2) level, ovarian aromatase protein content, and E2/free T ratio in the PCOS rats. Additionally, MET and Q increased preantral, antral, and preovulatory follicles and corpora lutea counts, while both treatments decreased atretic follicle count and eliminated the formation of cysts in the PCOS rats. MET and Q reduced ovarian Bax and elevated Bcl-2 protein abundance in the PCOS rats. Our study revealed that Q is as effective as MET in reducing hyperandrogenism via decreasing free T level and improving hypothalamic-pituitary-ovarian axis function. The results suggest that MET and Q may enhance E2 concentration, ovarian aromatase protein content, folliculogenesis, and decrease atresia via attenuation of hyperandrogenism in PCOS rats.

Targeted delivery of miR-218 via decorated hyperbranched polyamidoamine for liver cancer regression.

Hepatocellular carcinoma (HCC) is one of most common causes of cancer death worldwide. MicroRNA (miRNA) replacement gene therapy is a novel approach for HCC management. MiR-218 is a promising tumor suppressor miRNA that is down-regulated in HCC. Here, our aim was the targeted delivery of miR-218 expressing DNA plasmid (pmiR-218) to suppress HCC in vitro and in vivo. Hyperbranched polyamidoamine was synthesized via simple and economically one-pot reaction followed by decoration with lactobionic acid (LA-PAMAM) to selectively deliver and restore miR-218 expression in HCC. In vitro cytotoxicity investigations revealed the high biocompatibility of LA-PAMAM. Furthermore, decoration of hyperbranched polymer with LA moieties enabled LA-PAMAM to deliver pmiR-218 more efficiently to HepG2 cells compared to both PMAMA and naked pmiR-218. Such efficient delivery of miR-218 resulted in suppression of HepG2 proliferation and down-regulation of its oncogenic HOXA1 target. In vivo, LA-PAMAM/pmiR-218 treatment of HCC induced by DEN and CCl4 in mice leads to an obvious decrease in the number and size of HCC nodules. In addition, LA-PAMAM/pmiR-218 significantly improved the liver histological features, as well as down-regulated the HOXA1 in liver tissue. In conclusion, this study showed the potential of LA-PAMAM carrier for the targeted delivery of tumor suppressor miR-218 as a therapeutic candidate for HCC.

Quercetin stimulates the non-amyloidogenic pathway via activation of ADAM10 and ADAM17 gene expression in aluminum chloride-induced Alzheimer's disease rat model.

AIMS: Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder characterized by declined cognitive functions in the elderly. Quercetin (Q) is a potent flavonol that has neuroprotective effects on AD derangements. The present study aimed to evaluate the α-secretase stimulatory function of Q through activation of ADAM10 and ADAM17 gene expression in the aluminum chloride (AlCl3)-induced AD rat model. MAIN METHODS: After induction of AD in rats by oral administration of AlCl3 (50 mg/kg) for 28 days, the Q doses (25 and 50 mg/kg) were orally administered for 28 days. Rats performed the behavioral assessments during the last week of the treatment period. Hippocampi were harvested for assessments of the neurochemical and histopathological examinations and gene expression analysis. KEY FINDINGS: Administration of Q to AlCl3-induced AD rat model attenuated behavioral deficits, improved cholinergic and dopaminergic dysfunctions, and diminished insoluble amyloid ß (Aß) plaques aggregation in the hippocampus. These ameliorative effects of Q were associated with down-regulation of APP, BACE1, APH1, and PSEN1 and up-regulation of ADAM10 and ADAM17 gene expression levels in the hippocampus. SIGNIFICANCE: The present study suggests that Q might attenuate neurotransmission impairment, Aß aggregation in the hippocampus, and behavioral deficits in the AlCl3-induce AD rat model via up-regulating ADAM 10 and ADAM 17 (α-secretase) gene expression, leading to the inhibition of the amyloidogenic pathway. In support of the present finding, we suggest that ADAM10 and ADAM17 activation might be potential drug targets for AD to counteract the Aß aggregation and cognitive deterioration.

Evaluation of reproductive hormones in Egyptian workers occupationally exposed to di-2-ethylhexyl phthalate (DEHP): a cross-sectional study.

OBJECTIVES: Di-2-ethylhexyl phthalate (DEHP) is ubiquitous, known as an endocrine disruptor. DEHP is a widespread prevalence in general and occupational populations which raised great public concerns due to its potentially harmful health effects on the male reproductive system. We aimed to assess occupational levels of DEHP on gonadotropin and gonadal hormones including luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (TT), and sex hormone binding globulin (SHBG) and evaluate its potential effects on Asp327Asn polymorphisms SHBG gene. METHODS: We measured the levels of DEHP of 90 male workers in one of polyvinyl chloride (PVC) industry plant using enzyme-linked immunosorbent assay. Sex hormones were examined and Asp327Asn polymorphisms SHBG gene were detected by PCR-RFLP in all participants. RESULTS: The workers were divided into low- and high- DEHP exposed groups based on the geometric mean (GM) levels (183.86 U/L) in serum. TT and TT: LH ratio were negatively correlated to DEHP levels (r=-0.213, p=0.038), (r=-0.225, p=0.027), respectively. The linear regression analysis revealed that a 10-fold increase of serum DEHP was found to be associated with 2.07 fold decreased in TT and a 2.26 fold decreased in TT/LH ratio. CONCLUSIONS: Serum testosterone is negatively associated with DEHP exposure in occupational workers.

Expression profiling and analysis of some miRNAs in subcutaneous white adipose tissue during development of obesity.

BACKGROUND: MicroRNAs are emerging as new mediators in the regulation of adipocyte physiology and have been approved to play a role in obesity. Despite several studies have focused on microRNA expression profiles and functions in different metabolic tissues, little is known about their response to nutritional interventions in white adipose tissue during obesity stages, and whether they differ in this response to weight-reduction strategy is poorly understood. Our objectives were to study the dysregulation of some miRNAs in subcutaneous inguinal white adipose tissue during weight change, expansion/reduction; in response to both a high-fat diet and switching to a normal diet feeding, and to evaluate them as potential biomarkers and therapeutic targets for early obesity management METHOD: A hundred 6-week-old male Wister rats were randomly divided into a normal diet group (N.D), a high-fat diet group (H.F.D), and a switched to a normal diet group (H.F.D/N.D). At the beginning and at intervals 2 weeks, serum lipid, hormone levels, total body fat mass, and inguinal subcutaneous white adipose tissue mass (WAT) measurements were recorded using dual-energy X-ray absorptiometry (DEXA). The expression levels of microRNAs were evaluated using real-time PCR. RESULTS: Significant alterations were observed in serum glucose, lipid profile, and adipokine hormones during the early stages of obesity development. Alteration in rno-mir 30a-5p, rno-mir 133a-5p, and rno-mir 107-5p expression levels were observed at more than one time point. While rno-let-7a-5p, rno-mir 193a-5p, and rno-mir125a-5p were downregulated and rno-mir130a-5p was upregulated at all time points within 2 to 4 weeks in response to H.F.D feeding for 10 weeks. The impact of switching to normal diet has a reversed effect on lipid profile, adipokine hormone levels, and some miRNAs. The bioinformatics results have identified a novel and important pathway related to inflammatory signalling. CONCLUSION: Our research demonstrated significant alterations in some adipocyte-expressed miRNAs after a short time of high caloric diet consumption. This provides further evidence of the significant role of nutrition as an epigenetic factor in regulation of lipid and glucose metabolism genes by modulating of related key miRNAs. Therefore, we suggest that miRNAs could be used as biomarkers for adiposity during diet-induced obesity. Perhaps limitation in calories intake is a way to manipulate obesity and associated metabolic disorders. Further studies are needed to fully elucidate the role of microRNAs in the development of obesity.

Association between circulating microRNA-126 expression level and tumour necrosis factor alpha in healthy smokers.

Introduction: Smoking contributes to the death of a million people worldwide each year. Smokers experience an alteration in tumour necrosis factor-alpha (TNF-α), and the risk of expected lung cancer. The study aimed at investigating the expression levels of mir-126 and mir-124, as well as TNF-α as possible biomarkers of expected smoking-related diseases. Methods: Twenty-five male smokers' age and sex-matched with 25 non-smokers were recruited for the present study. Plasma expression levels of mir-126 and mir-124 were evaluated using quantitative real-time PCR. Lipid profile, TNF-α, interleukin-6 and C-reactive protein were assessed in plasma of each participant. Results: Plasma miR-126 was statistically down-regulated in smokers relative to non-smokers; however, mir-124 did not show any significant changes between groups. Among the measured parameters, mir-126 and tumour necrosis factor alpha (TNF-α) displayed a good discrimination and sensitivity between smokers and non-smokers (AUC = 0.809 (95% CI: 0.668-0.95; p < 0.001) and 0.742(95% CI: 0.584-0.9; p < 0.01), respectively. Also, the combined evaluation of miR-126 and TNF-α levels showed high discrimination (AUC= 0.889 (95% CI: 0.779-1.00; p < 0.0001), sensitivity = 85%, and specificity = 80% in the diagnosis of smokers with non-smokers. Conclusions: MiR-126 and TNF-α are potential biomarkers of smoking-related diseases and are important in assessing the expected tobacco-related harm.

MicroRNA-150 down Regulation in Acute Myeloid Leukaemia Patients and Its Prognostic Implication.

BACKGROUND: MicroRNAs (miRNAs) are small, non-coding RNAs that are important for post-transcriptional gene regulation in both healthy and morbid conditions. Numerous miRNAs promote tumorigenesis, while others have a tumour suppressive effects. Acute myeloid leukaemia (AML) is a heterogeneous group of genetically diverse hematopoietic malignancies with variable response to treatment. AIM: Our study aimed to investigate the possible role of miR-150 in de novo adult AML and the impact of its level on survival, and we used in the silicon analysis to predict the main target genes involved in miR-150 mediated cancer pathway. MATERIAL AND METHODS: We evaluated miR-150 expression profiling assay using TaqMan primer probes RT-PCR in the plasma of 50 adult AML patients, before the start of treatment and at day 28 of treatment, along with 20 normal adult control samples. miR-16 was used as an endogenous reference for standardisation. Follow-up of patients during treatment at day 28 of induction chemotherapy and after one year was done. RESULTS: In this study, we found a significantly lower level of miR-150 in AML patients when compared to controls (p = 0.005) with 0.62 fold change than in healthy controls. Patients were divided into two groups: the low miR-150 group (miR-150 < 1) and the high miR-150 group (miR-150 > 1). A statistically significant difference was found between the two groups regarding initial total leukocytic count and initial PB blast count while for the TLC, HB and PLT count at follow up. No difference in the overall survival between the low and the high miR-150 groups could be demonstrated. CONCLUSION: Our results suggest that miR-150 functions as a tumour suppressor and gatekeeper in inhibiting cell transformation and that its downregulation is required for leukemogenesis.

Down-regulation of circulating microRNA let-7a in Egyptian smokers.

Altered miRNAs were associated with cigarette smoking. The study aimed to examine the gene expression level of plasma let-7a among healthy smokers and compared it with the non-smokers. Forty subjects were recruited for the present study and classified into 21 smokers and 19 non-smokers, age, and sex were matched. The software that used to design functional primers was MIRprimer. Quantitative real-time PCR was employed to compare the relative expression of plasma let-7a. Results showed that the level of let-7a was down-regulated in smokers to 0.34fold (p = 0.006) that of the non-smokers. Plasma let-7a showed an area under curve (AUC) of 0.749 with sensitivity 43% and specificity 100%. In conclusion, plasma let-7a was significantly down-regulated in the smokers, and it might be considered a candidate biomarker to discriminate between smokers and non-smokers.