Comparative analysis of chemical profiles, antioxidant, antibacterial, and anticancer effects of essential oils of two Thymus species from Montenegro.

The essential oils of Thymus vulgaris (TVEO) and Thymus serpyllum (TSEO) show different biological activities. The aim of the study was to evaluate the biological activities of TVEO and TSEO from Montenegro. The main components of TVEO were p-cymene (29.52%), thymol (22.8%) and linalool (4.73%) while the main components of TSEO were p-cymene (19.04%), geraniol (11,09%), linalool (9.16%), geranyl acetate (6.49%) and borneol (5.24%). Antioxidant activity determined via DPPH for TVEO was 4.49 and FRAP 1130.27, while for TSEO it was estimated that DPPH was 4.88 µL/mL and FRAP was 701.25 µmol FRAP/L. Both essential oils were active against all tested bacteria, with the highest level of sensitivity of E. coli with MIC of 1.5625 µL/mL. Essential oils showed strong cytotoxic effects on human cancer cell lines, with IC50 values ranging from 0.20 to 0.24 µL/mL for TVEO and from 0.32 to 0.49 µL/mL for TSEO. TVEO caused apoptosis in cervical adenocarcinoma HeLa cells through activation of caspase-3 and caspase-8, while TSEO caused apoptosis through caspase-3. EOs decreased levels of oxidative stress in normal MRC-5 cells. HeLa cells treated with TVEO had reduced MMP2 expression levels, while cells treated with TSEO had lowered MMP2 and MMP9 levels. The treatment of HeLa cells with TVEO increased the levels of miR-16 and miR-34a, indicating potential tumor-suppressive properties. Our findings suggest that Thymus essential oils may be considered as good candidates for further investigation as cancer-chemopreventive and cancer-therapeutic agents.

MicroRNA networks linked with BRCA1/2, PTEN, and common genes for Alzheimer's disease and breast cancer share highly enriched pathways that may unravel targets for the AD/BC comorbidity treatment.

MicroRNAs (miRNAs) are involved in the regulation of various cellular processes including pathological conditions. MiRNA networks have been extensively researched in age-related degenerative diseases, such as cancer, Alzheimer's disease (AD), and heart failure. Thus, miRNA has been studied from different approaches, in vivo, in vitro, and in silico including miRNA networks. Networks linking diverse biomedical entities unveil information not readily observable by other means. This work focuses on biological networks related to Breast cancer susceptibility 1 (BRCA1) in AD and breast cancer (BC). Using various bioinformatics approaches, we identified subnetworks common to AD and BC that suggest they are linked. According to our results, miR-107 was identified as a potentially good candidate for both AD and BC treatment (targeting BRCA1/2 and PTEN in both diseases), accompanied by miR-146a and miR-17. The analysis also confirmed the involvement of the miR-17-92 cluster, and miR-124-3p, and highlighted the importance of poorly researched miRNAs such as mir-6785 mir-6127, mir-6870, or miR-8485. After filtering the in silico analysis results, we found 49 miRNA molecules that modulate the expression of at least five genes common to both BC and AD. Those 49 miRNAs regulate the expression of 122 genes in AD and 93 genes in BC, from which 26 genes are common genes for AD and BC involved in neuron differentiation and genesis, cell differentiation and migration, regulation of cell cycle, and cancer development. Additionally, the highly enriched pathway was associated with diabetic complications, pointing out possible interplay among molecules underlying BC, AD, and diabetes pathology.

Association of polymorphisms in TGFB1, XRCC1, XRCC3 genes and CD8 T-lymphocyte apoptosis with adverse effect of radiotherapy for prostate cancer.

The genetic background of each person might affect the severity of radiotherapy (RT)-induced normal tissue toxicity. The aim of study was to evaluate the influence of TGFB1 C-509T and Leu10Pro, XRCC1 Arg280His and XRCC3 Thr241Met polymorphisms as well as the level of radiation-induced CD8 T-lymphocyte apoptosis (RILA) on adverse effects of RT for prostate cancer (PCa). The study included 88 patients with localized or locally advanced PCa who were treated with RT. The polymorphisms were determined by PCR-RFLP analysis on DNA from peripheral blood mononuclear cells. RILA values were measured by flow cytometry. We found that CT genotype of TGFB1 C-509T could be protective biomarker for acute genitourinary (GU) and gastrointestinal (GI) radiotoxicity, while Thr variant of XRCC3 Thr241Met could predict the risk for acute GU radiotoxicity. Correlation between RILA values and toxicity was not detected. Univariate logistic regression analysis showed that Gleason score and risk group were risk factors for late GU, while for late GI radiotoxicity it was diabetes mellitus type 2. However, in multivariate model those were not proven to be significant and independent risk factors. Identification of assays combination predicting individual radiosensitivity is a crucial step towards personalized RT approach.

Dual function miR-205 is positively associated with ER and negatively with five-year survival in breast cancer patients.

BACKGROUND: Precise molecular characterization of breast cancer, especially triple negative (TNBC) as the most lethal subtype, is needed to stratify patients for the individual treatment approach. MicroRNA-205 (miR-205) has tumor-suppressive and oncogenic functions across different cancers. Therefore, miR-205 might have a different role in TNBC and estrogen receptor (ER) positive BC. Our aim was to investigate how miR-205 expression is associated with ER/progesteron receptor status, clinical parameters, pathohistological characteristics of BC, and survival of patients METHODS: We determined miR-205 relative expressions in 73 primary breast tumors (50 TNBC and 23 ER+) by quantitative Real-time polymerase chain reaction (qPCR) and compared it to clinicopathological characteristics and outcome. RESULTS: The highest levels of miR-205 were in the ER+ /PR+ group, and the lowest in the TNBC group (p = 0.009). Significantly higher levels of miR-205 were also observed in the ER+ compared with the ER-negative group, regardless of the PR status (p = 0.002). Low miR-205 expression level was associated with prognostic stage III in TNBC samples (p = 0.049). Patients who received adjuvant chemotherapy had significantly lower levels of miR-205 (p = 0.016). Patients who received hormone therapy had significantly higher levels of miR-205 (p = 0.007). The low-miR-205 patients had significantly higher 5-year survival rates (p = 0.041). CONCLUSION: The expression of miR-205 in BC is subtype-specific and high expression is associated with the ER+ tumors. The miR-205 expression might be a useful marker of TNBC progression. High miR-205 expression had a detrimental effect on BC patient outcome. Our results indicate that miR-205 might be utilized in clinical practice as a biomarker and an adjunct parameter for the selection of the most effective therapeutic modality.

Association between microRNAs 10b/21/34a and acute toxicity in glioblastoma patients treated with radiotherapy and temozolomide.

A personalized approach to chemoradiation is important in reducing its potential side effects and identifying a group of patients prone to toxicity. MicroRNAs have been shown to have a predictive potential for radiotoxicity. The goal of the study was to test if levels of miRNA in peripheral blood mononuclear cells of glioblastoma patients are associated with toxicity and to identify the peak time point for toxicity. MicroRNA-10b/21/34a levels were measured in 43 patients with and without toxicity, at baseline, at the 15th, and at the 30th fraction by Real-Time quantitative Polymerase Chain Reaction. MicroRNA-10b/21 levels increased with toxicity grade (p = 0.014; p = 0.013); miR-21/34a levels were significantly different between patients with and without toxicity at the 15th fraction (p = 0.030; p = 0.045), while miR-34a levels significantly changed during treatment (p < 0.001). All three miRNAs showed a significantly high positive correlation with one another. MiR-34a might be considered as a predictive factor for toxicity due to its changes during treatment, and differences between the groups with and without toxicity; miR-10b might be used to predict toxicity; miR-10b/21 might be used for predicting the grade of toxicity in GB patients.

MicroRNAs in Prostate Cancer Following Radiotherapy: Towards Predicting Response to Radiation Treatment.

Prostate cancer (PCa) is the second most frequently diagnosed male cancer worldwide. Early diagnosis of PCa, response to therapy, and prognosis still represent a challenge. Nearly 60% of PCa patients undergo radiation therapy (RT) which might cause side effects. Despite numerous researches in this field, predictive biomarkers for radiation toxicity are still not elucidated. MicroRNAs as posttranscriptional regulators of gene expression are shown to be changed during and after irradiation. MicroRNA level changes might be utilized to predict response to RT in the near future, which might help clinicians to make the decision on treatment regimens if needed. Individual radiation response results from the interactions among radiation treatment parameters and the biological background of each patient. In this review, we have listed and described miRNAs involved in response to RT in PCa and highlighted potential candidates for future biological tests predicting radiation response to RT, with the special focus on side effects of RT. According to described literature, we concluded that let-7, miR-21, miR-34a, miR-146a, miR-155, and members of miR-17/92 cluster might be promising candidates for biological tests predicting radiosensitivity of PCa patients undergoing radiation treatment. Predictive miRNA panels, especially for acute and late side effects of RT, can serve as a starting point for decisions for individualized RT planning. We believe that this review might be one step closer to understanding molecular mechanisms underlying individual radiation response of patients with PCa.

circRNAs in drug resistance of breast cancer.

Breast cancer (BC) is the most common heterogeneous disease in women and one of the leading causes of cancer-related death. Surgery, chemotherapy, radiotherapy, hormone, and targeted therapy are the gold standards for BC treatment. One of the significant challenges during the treatment of BC represents resistance to chemotherapeutics, resistance that severely limits the use and effectiveness of the drugs used for BC treatment. Therefore, it is essential to develop new strategies to improve therapeutic efficacy. Circular RNAs (circRNAs) are a large group of non-coding RNAs that covalently form closed circular loops by joining their 5', and 3'; ends. Accumulating evidence suggests that circRNAs have a vital role in cancer development, progression, and BC resistance to chemotherapy. The purpose of this review is to discuss the biological properties of circRNAs, and how circRNAs induce resistance to conventional therapeutic anti-cancer drugs used in BC treatment, by emphasizing and summarizing the potential roles of circRNAs in mechanisms of drug resistance, such as drug efflux, apoptosis dysfunction, autophagy, and DNA damage repair. CircRNAs are associated with drug resistance via ATP-binding cassette (ABC) efflux transporters, while some others by inhibition of cell apoptosis, thus leading to resistance to tamoxifen in BC cells. In contrast, others are involved in the promotion of BC cells chemoresistance by doxorubicin-induced autophagy. CircRNAs may have clinical significance in regulating or overcoming BC drug resistance and may give directions towards a novel approach to personalized BC treatment. CircRNAs may significantly contribute to the identification of new therapeutic targets for the prevention of BC chemoresistance.

Antitumor activity, DNA and BSA interactions of novel copper(II) complexes with 3,4-dihydro-2(1H)-quinoxalinones.

In order to discover new therapeutically active agents a series of novel copper(II) complexes with 3,4-dihydro-2(1H)-quinoxalinones were synthesized. All complexes were characterized by IR and EPR spectroscopic techniques and examined for their cytotoxic effect on human cancer cell lines HeLa, LS174, A549 and normal fibroblasts (MRC-5). For further examination of the cytotoxic mechanisms of novel complexes, three of them were chosen for analysing their effects on the distribution of HeLa cells in the cell cycle phases. The results of the flow cytometry analysis suggest that tested complexes lead to time-dependent accumulation of the cells in S and G2/M phases. The strongest accumulation effect showed complex 2d after 48 h of incubation. Competitive experiments with ethidium bromide (EB) indicated that tested compound 2d have affinity to displace EB from the EB-DNA complex through intercalation. Also, the binding parameters values for 2d-BSA complex showed that a reversible 2d-BSA complex is formed and ligand 2d can be stored and carried by BSA.

Cytotoxic activities of Hypericum perforatum L. extracts against 2D and 3D cancer cell models.

Six extracts were obtained from plant species Hypericum perforatum L., collected at Samsun in Turkey. The aim of this study was to examine the mechanisms of the anticancer activity of these extracts. Methanol, ethyl-acetate and hexane were used as a solvents for extraction from both branch-body part of the plant (extracts 1, 2 and 3) and from plant flowers (extracts 4, 5 and 6). The cytotoxic effects of the extracts were determined against 2D and 3D cancer cell models. Cell cycle changes of treated HeLa cells were analyzed by flow cytometry. Measurements of gene and microRNA expression levels in treated HeLa cells were done by quantitative real time PCR. Five examined extracts (2-6) exerted selective concentration-dependent cytotoxic effects on HeLa, K562, and A549 cancer cells, while the extract 1 exhibited very weak cytotoxicity. The extract 6 showed the highest intensity of cytotoxic activity. All tested extracts (2-6) demonstrated the ability to induce apoptosis in HeLa cells through activation of caspase-3. These extracts remarkably decreased gene expression levels of MMP2, MMP9, TIMP3, and VEGFA in HeLa cells. Flower extracts might have stronger effects on miR128/193a-5p/335 level changes than branch-body extracts. Hypericum perforatum extracts exerted weaker cytotoxic effects on 3D HeLa spheroids when compared with their effects on 2D monolayer HeLa cells. Taken together, results of our research may suggest the promising anticancer properties of the Hypericum perforatum extracts.

Breast Cancer Response to Therapy: Can microRNAs Lead the Way?

Breast cancer (BC) is a leading cause of death among women with malignant diseases. The selection of adequate therapies for highly invasive and metastatic BCs still represents a major challenge. Novel combinatorial therapeutic approaches are urgently required to enhance the efficiency of BC treatment. Recently, microRNAs (miRNAs) emerged as key regulators of the complex mechanisms that govern BC therapeutic resistance and susceptibility. In the present review we aim to critically examine how miRNAs influence BC response to therapies, or how to use miRNAs as a basis for new therapeutic approaches. We summarized recent findings in this rapidly evolving field, emphasizing the challenges still ahead for the successful implementation of miRNAs into BC treatment while providing insights for future BC management.The goal of this review was to propose miRNAs, that might simultaneously improve the efficacy of all four therapies that are the backbone of current BC management (radio-, chemo-, targeted, and hormone therapy). Among the described miRNAs, miR-21 and miR-16 emerged as the most promising, closely followed by miR-205, miR-451, miR-182, and miRNAs from the let-7 family. miR-21 inhibition might be the best choice for future improvement of invasive BC treatment.New therapeutic strategies of miRNA-based agents alongside current standard treatment modalities could greatly benefit BC patients. This review represents a guideline on how to navigate this elaborate puzzle.

Bone microRNA-21 as surgical stress parameter is associated with third molar postoperative discomfort.

OBJECTIVE: To evaluate an association between bone levels of inflammation/oxidative stress mediators and postoperative discomfort after third molar conventional or piezosurgery. MATERIAL AND METHODS: Twenty-six subjects with bilaterally impacted mandibular third molars, who underwent either piezo or conventional surgery, were included in a split-mouth design study. MicroRNA-21 (miR-21) expression, interleukin-1 beta (IL-1ß), and vascular endothelial growth factor (VEGF) proteins, as well as superoxide dismutase (SOD) activity in alveolar bone, were evaluated. Pain intensity, the first pain appearance, analgesic first use and total dose taken, trismus, and swelling were clinically recorded. RESULTS: MiR-21 expression was higher while VEGF protein was lower in piezosurgery vs. conventional groups. The differences in IL-1ß protein and SOD activity were not significant between groups. The pain intensity on the first day was significantly decreased in piezosurgery group. The first pain appearance and the first analgesic taken were reported sooner in conventional vs. piezosurgical group. Significantly pronounced trismus on the third day following conventional surgery was found. In conventional group, significantly increased trismus was observed on the third compared to the first postoperative day. MiR-21 showed significant correlation with the first pain appearance. CONCLUSION: Delayed onset of less pronounced postoperative pain after piezosurgical vs. conventional extraction of impacted lower third molar was significantly associated with expression of bone miR-21. CLINICAL RELEVANCE: Alveolar bone miR-21 may reflect surgical stress and is associated with third molar postoperative pain onset.

Evaluation of cytokine expression and circulating immune cell subsets as potential parameters of acute radiation toxicity in prostate cancer patients.

One of the challenges of radiation oncology in the era of personalized medicine is identification of biomarkers associated with individual radiosensitivity. The aim of research was to evaluate the possible clinical value of the associations between clinical, physical, and biological factors, and risk for development of acute radiotoxicity in patients with prostate cancer. The study involved forty four patients treated with three-dimensional conformal radiotherapy. The concentrations of IL-1ß, IL-2, IL-6, IFN-γ and TGF-ß1 were assessed before radiotherapy, after 5th, 15th and 25th radiotherapy fractions, at the end, and 1 month after the end of radiotherapy. Cytokine gene expression was determined in peripheral blood mononuclear cells. The univariate analysis of circulating cytokine levels during radiotherapy showed that increased serum concentrations of IL-6 were significantly associated with higher grade of acute genitourinary toxicity. The multivariate analysis demonstrated that increased level of IL-6 during the radiotherapy was significantly associated with higher grade of acute genitourinary toxicity across treatment. TGF-ß expression levels significantly decreased during course of radiotherapy. Research indicates that changes in circulating cytokine levels might be important parameter of radiotoxicity in patients with prostate cancer. These findings suggest that future studies based on multi-parameter examination are necessary for prediction of individual radiosensitivity.

Discovery of the Biginelli hybrids as novel caspase-9 activators in apoptotic machines: Lipophilicity, molecular docking study, influence on angiogenesis gene and miR-21 expression levels.

In order to investigate potential therapeutically agents, novel products of Biginelli reaction (4a-l) were synthesized and exposed to cytotoxic and caspase activities, angiogenesis, cell cycle distribution, gene and microRNA expression levels, lipophilicity assessment and docking study. Among the twelve novel compounds (4a-l) evaluated for the cytotoxic activity, five of them (4c, 4d, 4f, 4k and 4l) that showed excellent activity on the tested cell lines (HeLa, LS174 and A549) were selected for further evaluation. Interestingly, compound 4f has up to three times higher selectivity index (SI) towards cancer cells than cisplatin (on HeLa, LS174 and A549 SI = 18.2, 13.5 and 11.2, respectively). The obtained results from cell cycle distribution and caspase activity indicate that tested compounds (4c, 4d, 4f, 4k and 4l) promoted caspase-9 activation, implicated in the intrinsic pathway of apoptosis. Lipophilicity of 4a-l was determinate by using reversed-phase high-performance liquid chromatography.

Association between miR-21/146a/155 level changes and acute genitourinary radiotoxicity in prostate cancer patients: A pilot study.

INTRODUCTION: Nearly sixty percent of patients with prostate cancer (PCa) undergo radiation therapy (RT). During the course of treatment patients may experience normal tissue reactions. It is a well established fact that genetic and epigenetic mechanisms, such as microRNA (miRNA) level changes might be associated with radiotoxicity, as a response to irradiation. MATERIALS AND METHODS: This is the first study that has investigated levels of radiosensory miRNAs in association with acute genitourinary radiotoxicity extracted from peripheral blood mononuclear cells (PBCs), in three points; before RT (BRT), after RT (ART) and on the first control examination (FCONT). We measured levels of miR-21/146a/155 expression by quantitative real-time PCR (qRT-PCR), comparative ΔΔCt method, in fifteen patients with localized prostate cancer, treated with three-dimensional conformal radiotherapy (3DCRT). Nine subjects have experienced acute genitourinary (GU) radiotoxicity whereas six where without GU radiotoxicity. RESULTS: Firstly, we detected the highest levels of miR-21 in ART group (p = 0.043) in the patients with acute GU radiotoxicity. Secondly, we found trend towards higher miR-21 levels and significantly higher levels of miR-146a/155 within the patients with acute GU toxicity than in patients without (p = 0.068, p = 0.016, and p = 0.010, respectively). Thirdly, we detected significant change in miR-146a/155 levels within the patients without acute GU radiotoxicity during RT p = 0.042, and p = 0.041, respectively). CONCLUSION: miR-21/146a/155 might be useful potential factors of radiosensitivity and acute genitourinary radiotoxicity in prostate cancer patients. miRNA might have great potential as predictors of various pathological conditions extracted from PBMCs.

Novel 1,3,4-thiadiazole-chalcone hybrids containing catechol moiety: synthesis, antioxidant activity, cytotoxicity and DNA interaction studies.

Hybrid compounds that combine the 1,3,4-thiadiazole-containing catechol moiety with a chalcone motif were synthesized and examined for their antioxidant activity, cytotoxicity, and DNA-binding activity. A series of thirteen compounds showed strong antioxidant and cytotoxic effects on human acute promyelocytic leukemia HL-60 cells. Several compounds exerted good cytotoxic activities on cervical adenocarcinoma HeLa cells. The treatment of HeLa cells with IC50 and double IC50 concentrations of the compounds 5a, 5c, 5f, and 5m induced a statistically significant increase in the percentage of cells within a subG1 cell cycle phase. The examined compounds caused G2/M cell cycle arrest in HeLa cells. Each of these compounds triggered apoptosis in HeLa cells through activation of caspase-3, the main effector caspase, caspase-8, which is involved in the extrinsic apoptotic pathway, and caspase-9, which is involved in the intrinsic apoptotic pathway. All of the examined compounds decreased the expression levels of MMP2 in HeLa cells and levels of protumorigenic miR-133b. Compounds 5a and 5m lowered the expression level of oncogenic miR-21 in HeLa cells. In addition, compounds 5a, 5f, and 5m decreased the expression levels of oncogenic miR-155 while the treatment of HeLa cells with compounds 5a, 5c, and 5f increased expression of tumor-suppressive miR-206. Observed effects of these compounds on expression levels of four examined miRNAs suggest their prominent cancer-suppressive activity. An investigation by absorption and fluorescence spectroscopy showed more efficient calf thymus DNA binding activity of the compound 5m in comparison to other tested compounds. Results of a pUC19 plasmid cleavage study and comet assay showed DNA damaging activities of compounds 5a and 5c.

Highly selective anthraquinone-chalcone hybrids as potential antileukemia agents.

A series of 23 novel anthraquinone-chalcone hybrids containing amide function was synthesized and structurally characterized. Sixteen compounds exerted strong cytotoxic activities against K562, Jurkat and HL-60 leukemia cell lines and significantly lower cytotoxic effects against normal MRC-5 cells, indicating very high selectivity in their anticancer action. The compounds 6g, 6u and 6v activate apoptosis in K562 cells through the extrinsic and intrinsic apoptotic pathway. The compound 6e triggered apoptosis in K562 cells only through the extrinsic apoptotic pathway. Treatment of K562 cells with each of these four compounds caused decrease in the expression levels of MMP2, MMP9, and VEGF, suggesting their anti-invasive, antimetastatic and antiangiogenic properties. The compounds 6g and 6v downregulated expression levels of miR-155 in K562 cells, while compounds 6e and 6u upregulated miR-155 levels in treated cells, in comparison with control cells. The structure-based 3-D QSAR models for 6f, 6e, 6i and 6l describe pro-apoptotic activity against caspase-3.

Significance of miR-15a-5p and CNKSR3 as Novel Prognostic Biomarkers in Non-Small Cell Lung Cancer.

BACKGROUND: In recent years, targeted cancer treatment methods at various molecular levels have been developed for Non-Small Cell Lung Cancer (NSCLC), one of two major subtypes of lung cancer. miRNAbased clinical trials are currently the preferred targeted therapeutic strategy. Also, ceRNAs (competing endogenous RNA) would be the newest and the most effective approach to uncover novel interactions between mRNAs and miRNAs in NSCLC carcinogenesis. There are many factors influencing the efficiency of a miRNA to suppress or silence translation of the target mRNA. The most effective event is the presence of other RNAs showing ceRNA activity. These RNAs contain binding sites for specific miRNAs and enable miRNAs to bind these pseudo targets, instead of the original binding sites on the target mRNA. Therefore, the mRNA of the target gene is less affected by this miRNA, while the amount of miRNA remains the same in the media. METHOD: For this project, we determined that five clinically important different oncogenes (PDL1, FGFR1, DDX3X, SLC1A5, FXR1 ) are involved in the pathogenesis of NSCLC. For this purpose, we transfected model NSCLC cell line, A549, with miRNAs (miR-150-5p, miR-15a-5p, miR-503-5p) targeting these oncogenes to investigate whether these oncogenes will be suppressed at the mRNA level and also how the suppression efficiency of these miRNA on the oncogenes will be affected by possible ceRNA (CNKSR3, POU2F1, HIPK2) activities. RESULTS: miR-15a-5p was determined to have the most suppressive effect on the five genes and three potential ceRNAs (p<0.05). Furthermore, CNKSR3 was the ceRNA most affected by all three miRNAs (p<0.05). CONCLUSION: CNKSR3 was affected more than the oncogenes known to act on NSCLC and this might make it a stronger and novel marker for use in possible treatment regimens designed using miR-15a-5p silencing effect on oncogenes in NSCLC pathogenesis. According to the literature, this is the first study associating NSCLC with miR-15a-5p and CNKSR3.

Estradiol-mediated regulation of hepatic iNOS in obese rats: Impact of Src, ERK1/2, AMPKα, and miR-221.

PURPOSE: This study aimed to investigate in vivo effects of estradiol on the regulation of hepatic inducible nitric oxide synthase (iNOS) expression in the high fat (HF) diet-induced obesity. Also, we aimed to investigate whether activation of the extracellular signal-regulated kinase (ERK1/2), adenosine monophosphate-activated protein kinase (AMPK), Src kinase, and miR-221 is involved in estradiol-mediated regulation of iNOS in the liver of obese male Wistar rats. Male Wistar rats were fed a standard laboratory diet or a HF diet for 10 weeks. Half of HF rats were treated with estradiol intraperitoneally (40 µg/kg), whereas the other half were placebo-treated 24 H before euthanasia. Results show that estradiol treatment of HF rats decreased hepatic iNOS mRNA (P < 0.05) and protein expression (P < 0.01), the protein levels of p65 subunit of nuclear factor κB (P < 0.05) and ERα (P < 0.05), ERK1/2 phosphorylation (P < 0.001), and ERα/Src kinase association (P < 0.05). By contrast, hepatic Src protein level (P < 0.05), AMPKα phosphorylation (P < 0.05), and miR-221 expression (P < 0.05) were increased in HF rats after estradiol treatment. Our results indicate that estradiol in vivo regulates hepatic iNOS expression in obese rats via molecular mechanisms involving ERK1/2, AMPK, Src, and miR-221 signaling.

Expression of VHL tumor suppressor mRNA and miR-92a in papillary thyroid carcinoma and their correlation with clinical and pathological parameters.

A growing body of evidence suggests a role of the von Hippel-Lindau (VHL) tumor suppressor gene in the progression of papillary thyroid carcinoma (PTC). Our previous study of VHL in PTCs showed that lower VHL expression was associated with aggressive tumor features, but we found no evidence for VHL downregulation through common genetic or epigenetic modifications. Several studies pointed to a role of microRNA-92a (miR-92a) in the regulation of VHL expression in different cancers. In the present study, we examined the expression levels of VHL mRNA and miR-92a in 42 pairs of PTCs and matched non-tumor thyroid tissues by means of quantitative RT-PCR. We explored the correlation between them and their association with clinicopathological parameters. The results revealed that both VHL and miR-92a were either up- or downregulated in PTCs compared to corresponding non-tumor tissues. On univariate analysis, lower VHL levels were significantly associated with extrathyroid spread (P = 0.022) and capsular invasion (P = 0.032). Multivariate analysis confirmed the association of low VHL with extrathyroid spread (OR 0.246, 95% CI 0.069-0.872, P = 0.038). Higher miR-92a among PTC tissues associated with the presence of nodal metastases (univariate analysis: P = 0.012; multivariate: OR 4.703, 95% CI 1.109-19.938, P = 0.036). A negative correlation between VHL and miR-92a was observed in a subgroup of PTCs having vascular invasion (P = 0.033, r = - 0.673). The data here reported demonstrate that the expression of both VHL and miR-92a is deregulated in PTC tissues and that in some PTCs they may have opposite roles. These roles, as well as their diagnostic and/or prognostic utility, remain to be clarified.