Osteosarcoma is the most common type of bone cancer in children and adolescents. MicroRNAs (miRNAs) play important roles in the development, differentiation, and function of different cell types and in the pathogenesis of various human diseases. miRNAs are differentially expressed in normal and cancer cells. The investigation of miRNA expression between healthy subjects and patients with osteosarcoma is crucial for future clinical trials. In this study, the expression levels of miRNAs were detected by qRT-PCR. Correlation between expression levels of tow miRNAs and different clinicopathological characteristics were analyzed using the χ (2) test. Survival rate was detected using the log-rank test and Kaplan-Meier method. qRT-PCR was shown that expression levels of miR-29b and miR-422a were strongly decreased in osteosarcoma bone tissue compared with noncancerous bone tissues. Our result indicated that the low expression levels of miR-29b and miR-422a showed strong correlation with large tumor size (P = 0.20; 0.029), advanced TNM stage (P = 0.001; 0.012), distant metastasis (P = 0.008; 0.019), and grade of tumor (P = 0.009; 0.016). Kaplan-Meier survival analysis showed that the low expressions of miR-29b/miR-422a were correlated with shorter time overall survival (log-rank test, P = 0.009; P = 0.013). Moreover, multivariate Cox proportional hazards model indicated that miR-29b and miR-422a (P = 0.024; P = 0.016) were independent prognostic markers of overall survival of patients. Our result indicated that downregulation of miR-29b and miR-422a may be linked to the prediction of poor prognosis, indicating that miR-29b and miR-422a may be a valuable prognostic marker for osteosarcoma patients.

IntroductionThe aim of this study was to investigate the expression levels of microRNA-182 and microRNA-183 and their association with clinicopathological features in patients with osteosarcoma.Material and methodsTotal RNA was purified from samples and noncancerous bone tissues and then quantitative real-time polymerase chain reaction was applied to evaluate the expression levels of microRNAs, and their relationship with clinicopathological features and survival in osteosarcoma patients.ResultsOur findings showed that expression of MiR-182 was clearly lower in osteosarcoma bone tissue (mean ± SD: 2.84 ±.07) compared with noncancerous bone tissues (6.23 ±1.72, p = 0.004). On the other hand, lower expression of MiR-183 was seen in osteosarcoma bone tissue (1.43 ±0.59) when compared with normal tissues (4.36 ±2.47, p = 0.036). Decreased expression of MiR-182 was clearly correlated with advanced clinical stage (p = 0.001), metastasis or recurrence (p = 0.024), and large tumor size (p = 0.032). Decreased expression of MiR-183 was associated with advanced TNM stage (p = 0.004), and metastasis or recurrence (p = 0.002). A multivariate Cox proportional hazards model revealed that low expression of MiR-182 and MiR-183 (p = 0.02; p = 0.016), TNM stage (p = 0.04), and metastasis or recurrence (p = 0.03) were significantly associated with poor survival as independent prognostic factors.ConclusionsThese findings suggest that MiR-182 and MiR-183 may be associated with progression and metastasis of osteosarcoma.

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Background:Shiga-toxigenic Escherichia coli is an important human pathogen cause of diarrhea, hemorrhagic colitis, hemolytic uremic syndrome and thrombotic thrombocytopenic purpura in humans is a significant public health.Objectives:The aim of this study was to determine the molecular characteristics and antimicrobial resistance properties of Shiga toxigenic Escherichia coli (STEC) strains with respect to their seasonal, age and geographical distributions in Iranian pediatric patients with and without diarrhea.Patients and Methods:Four hundred and eighty swab samples were taken from pediatric patients with and without diarrhea of four major provinces of Iran. Swab samples were immediately cultured and the positive culture samples were analyzed by the polymerase chain reaction (PCR) method. Finally, antimicrobial susceptibility testing was performed using the disk diffusion method in Mueller-Hinton agar.Results:In total, 118 out of 200 diarrheic stool samples (59%) and 77 out of 280 non-diarrheic stool samples (27.5%) were positive for E. coli. Samples taken from one to ten months old cases (73.33%) and those from Shiraz province (81.13%) were the most commonly infected. Samples taken in the summer season (91.66%) were the most commonly infected. A significant difference was shown between AEEC and EHEC strains of E. coli. The genes encoding Shiga toxins and intimin protein were the most commonly detected in all strains. O26 (33.33%), O111 (18.18%) and O91 (12.12%) serogroups had the highest incidence in patients with and without diarrhea. Prevalence of the genes that encode resistance against ampicillin (CITM), gentamicin (aac(3)-IV) and tetracycline (tetA) were 80.30%, 75.75% and 65.15%, respectively. The STEC strains harbored the highest levels of resistance against ampicillin (84.84%), gentamycin (78.78%), tetracycline (50%) and sulfamethoxazole (40.90%) antibiotics. We found that 55.08% of diarrheic and 1.29% of non-diarrheic E. coli isolates were resistant to more than six antibiotics.Conclusions:Accurate control programs should be organized for antibiotic prescription especially during warmer seasons in Iran. Primary treatment of diarrheic patients with co-trimoxazole, cefotaxime and ceftriaxone is effective.