MicroRNA-32 functions as a tumor suppressor and directly targets EZH2 in uveal melanoma.

MicroRNA-32 (miR-32) has been shown to be dysregulated in some human malignancies and this has been found to be correlated with tumor progression. However, its role in uveal melanoma formation and progression remains largely unknown. Thus, the aim of this study was to explore the expression and function of miR-32 in human uveal melanoma. Using quantitative reverse transcription-polymerase chain reaction, we detected miR-32 expression in uveal melanoma tumor tissues and cell lines. The effects of miR-32 on the biological behavior of uveal melanoma cells were also investigated. Finally, the potential regulatory function of miR-32 on EZH2 expression was confirmed. miR-32 expression levels were significantly downregulated in uveal melanoma samples and cell lines (both P < 0.01). Ectopic expression of miR-32 could inhibit uveal melanoma cell proliferation, migration, and invasion, and promote cell apoptosis in vitro. Further, EZH2 was confirmed as a direct target of miR-32 by using the luciferase reporter assay. These findings indicate that miR-32 may function as a novel tumor suppressor in uveal melanoma and could be a potential therapeutic target for this disease.

Correlation of miR-494 expression with tumor progression and patient survival in pancreatic cancer.

MicroRNA-494 (miR-494) expression is aberrant in various types of human cancer. However, the prognostic value of miR-494 in pancreatic cancer remains unclear. The level of miR-494 expression was determined in 99 pairs of primary pancreatic cancer and their corresponding, adjacent non-tumor tissues by using quantitative reverse transcriptase polymerase chain reaction. We also analyzed the associations between miR-494 expression and clinicopathological features. The survival correlations were analyzed by using the Kaplan-Meier method and Cox proportional hazards model. The level of miR-494 expression was significantly downregulated in pancreatic cancer tissues (mean relative expression level ± SD, 0.48 ± 0.11) as compared to matched adjacent normal tissues (1.80 ± 0.28, P < 0.05). We found significant correlations between the miR-494 expression levels and TNM stage (P = 0.009), lymphatic invasion (P = 0.036), vascular invasion (P = 0.011), distant metastasis (P = 0.007), and tumor grade (P = 0.031). Pancreatic cancer patients with a low miR-494 expression level had a shorter overall survival than those with a high miR-494 expression level (P < 0.05). Reduced miR-494 expression in pancreatic cancer tissues is correlated with tumor progression and might be an independent, poor prognostic factor for patients with pancreatic cancer.

Nucleotide mismatches of foot-and-mouth disease virus during replication.

As there is a lack of error correction mechanisms during RNA replication, foot-and-mouth disease virus (FMDV) has a very high mismatch rate, which leads to a high mutation rate, in the range of 10(-3) to 10(-5) per nucleotide site per genome replication. We examined the nucleotide mismatch of FMDV during replication, based on the whole genomes of the 7 serotypes retrieved from NCBI. With the Mega bio-software, SPSS, and Microsoft Excel, we studied the nucleotide differences compared to the sequence in the RefSeq database, and developed two probable mutation models, i.e., once mutation model and complication mutation model. Further analysis on the nucleotide mismatch during replication was made. We found that FMDV share similar difference rates between nucleotide and reverse differences, for example the mutation U→C and C→U. We also found that each nucleotide has its domain mismatch, and the virus kept a constant nucleotide composition during mutations.

Endothelial nitric oxide synthase gene polymorphisms and essential hypertension in Han Chinese.

We examined the effect of polymorphisms in the endothelial nitric oxide synthase gene on the risk for essential hypertension in a Han Chinese population through a meta-analysis of data from 15 studies. Associations between increased risk for essential hypertension and 4b/a were obtained in a dominant model and allele contrast (aa + ab vs bb: odds ratio (OR)(FE) = 1.26, 95% confidence interval (CI) = 1.10-1.44; a vs b allele: OR(FE) = 1.23, 95%CI: 1.09-1.40). Four studies with sample sizes over 500 produced similar results. No evidence of publication bias was found. Also, no significant heterogeneity was observed among these studies. When we examined the G894T polymorphism, we found a marginally significant association for allele contrast and the recessive model when all the eligible studies were pooled together. However, there was no evidence for a significant association after the exclusion of two studies deviating from Hardy-Weinberg equilibrium in the control group. Heterogeneity among studies was observed. Results of cumulative and recursive cumulative meta-analysis indicated that more studies are needed to objectively determine the effects of these two polymorphisms.