Pre-clinical and clinical importance of miR-21 in human cancers: Tumorigenesis, therapy response, delivery approaches and targeting agents.

The field of non-coding RNA (ncRNA) has made significant progress in understanding the pathogenesis of diseases and has broadened our knowledge towards their targeting, especially in cancer therapy. ncRNAs are a large family of RNAs with microRNAs (miRNAs) being one kind of endogenous RNA which lack encoded proteins. By now, miRNAs have been well-coined in pathogenesis and development of cancer. The current review focuses on the role of miR-21 in cancers and its association with tumor progression. miR-21 has both oncogenic and onco-suppressor functions and most of the experiments are in agreement with the tumor-promoting function of this miRNA. miR-21 primarily decreases PTEN expression to induce PI3K/Akt signaling in cancer progression. Overexpression of miR-21 inhibits apoptosis and is vital for inducing pro-survival autophagy. miR-21 is vital for metabolic reprogramming and can induce glycolysis to enhance tumor progression. miR-21 stimulates EMT mechanisms and increases expression of MMP-2 and MMP-9 thereby elevating tumor metastasis. miR-21 is a target of anti-cancer agents such as curcumin and curcumol and its down-regulation impairs tumor progression. Upregulation of miR-21 results in cancer resistance to chemotherapy and radiotherapy. Increasing evidence has revealed the role of miR-21 as a biomarker as it is present in both the serum and exosomes making them beneficial biomarkers for non-invasive diagnosis of cancer.

Effect of transcranial direct current stimulation on short-term and long-term treatment of chronic tinnitus.

OBJECTIVE: This study was conducted to investigate the effectiveness of anodal and cathodal methods in reducing the intensity of tinnitus and to compare them with the control. METHODOLOGY: This randomized double-blind clinical trial with case and control groups was conducted in Al-Zahra Hospital in Isfahan between 2015 and 2016. In this trial, 51 patients with tinnitus, for at least one year, were selected among those outpatients visiting the throat, nose and ear clinic within this period. Inclusion criteria were patients on electrical stimulation prohibition, with Ménière's disease, otosclerosis, chronic headache, and pulsatile tinnitus. Patients were randomly divided in three equal-sized groups: anodal stimulation group, cathodal stimulation group, and control group. The subjects received 20-min current stimulation (2 mA). Five subjects were selected from those with a significant difference between the stimulated states (anodal or cathodal) and/or control. They received weekly transcranial electrical stimulation for two months, and their long-term recovery from tinnitus was investigated. Data analysis was done with SPSS20. RESULTS: Findings showed no significant between-groups difference in mean scores of tinnitus before the intervention (p = .68); whereas, this difference was significant immediately after the intervention (p = .02) and 1 h after it (p = .03). The mean score of tinnitus in the anodal stimulation group was significantly lower than the control; whereas, no significant difference was observed between the anodal and cathodal stimulation groups, and between the cathodal and control groups (p < .05). Findings also showed that the mean scores of tinnitus in two cathodal stimulation groups (p = .24) and control group (p = .62) were not significantly different at three different points of time; whereas, this score was significantly different in the anodal group at these time points (p = .01). CONCLUSION: In conclusion, anodal stimulation was more effective than the cathodal and control stimulation in reducing the intensity of tinnitus in the short term.

The prevalence of dental anxiety and fear in patients referred to Isfahan Dental School, Iran.

BACKGROUND: Dental anxiety and fear are major complications for both patient and dental care provider. The purpose of this study was to assess the prevalence of dental anxiety and fear in patients who referred to Isfahan Dental School and their relation to their age, gender, educational level, past traumatic experiences and frequency of dental visits. MATERIALS AND METHODS: In this cross-sectional study, 473 patients were provided with a questionnaire including three sections. First section contained questions concerning their age, gender, educational level, frequency of dental visits, reasons for irregular attendance and existence of past traumatic experiences. Second section comprised a Farsi version of Modified Dental Anxiety Scale (MDAS); and third included a Farsi version of dental fear survey (DFS). Data were analyzed by t-test, ANOVA, Pearson and Spearman correlation tests. RESULTS: The prevalence of dental anxiety among the study population was 58.8%. No correlation was found between age and MDAS (r = -0.08, P = 0.07) and DFS (r = -0.03, P = 0.53). Women demonstrated higher anxiety (P < 0.001) and fear (P = 0.003). Education had no significant effect on dental anxiety (r = -0.046, P = 0.32) and dental fear (r = -0.017, P = 0.79). Previous traumatic experiences were found to result in elevated anxiety and fear (P < 0.001). There was an inverse relationship between frequency of dental attendance and anxiety (r = -0.128, P = 0.008). CONCLUSIONS: Within the limitations of this study, anxiety associated with dental treatment was widespread in the study population. Dental fear and anxiety were not affected by age or education level. Dental fear and anxiety were higher in women. In addition, people who visited the dentist more regularly and individuals without previous traumatic dental experiences were less anxious.