The polymorphism in miR-25 attenuated the oncogenic function in gastric cancer

The association between polymorphisms in miRNA and the cholinesterase activity of workers in an omethoate-exposed environment

To explore the association between polymorphisms in microRNAs (miRNAs) and the cholinesterase (ChE) activity in omethoate-exposed workers, we recruited 180 omethoate-exposed workers and 115 controls to measure their ChE activity using acetylcholine and dithio-bis-(nitrobenzoic acid) and genotype susceptible SNPs in their miRNA by time-of-flight mass spectrometry. ChE activity in the exposure group was lower than that in the control group (P < 0.001). The analysis of covariance result showed that ChE activity was lower in the (- -/- T) genotype in miR-30a rs111456995 (1.97 ± 0.47) than in the TT genotype (2.23 ± 0.59) of the exposure group (P = 0.004). Multivariate linear regression was performed to find influencing factors on ChE activity, and variables kept in the model included omethoate exposure (b = -1.094, P < 0.001), gender (b = -0.381, P < 0.001), miR-30a rs111456995 (- -/- T)(b = -0.248, P < 0.001), and drinking (b = 0.258, P =0.019). The results suggest that individuals carrying a (- -/- T) genotype in miR-30a rs111456995 were more susceptible to damage in their cholinesterase induced by omethoate exposure.

Identification of the association between rs41274221 polymorphism in the seed sequence of microRNA-25 and the risk of neonate sepsis

BACKGROUND

Many studies have investigated the role of microRNA-25 (miR-25) in the initiation and progression of sepsis in newborns. In this study, we aim to explore how rs41274221 polymorphism in miR-25 compromises the interaction between miR-25 and CD69, so as to understand the mechanisms involved in the control of sepsis in newborns.

METHODS

Computational analysis, luciferase assay, real-time polymerase chain reaction (PCR), and western blot analysis were performed in this study.

RESULTS

The luciferase assays results showed that CD69 was a target gene of miR-25, because the luciferase activity in cells transfected with wild type CD69 was much lower than that in the cells transfected with mutant CD69 or the scramble control. Real-time PCR and western blot analysis results showed that the expression of miR-25 in sepsis patients was significantly upregulated as compared with that in the normal control group, and the CD69 position ratio as well as the messenger RNA (mRNA) and protein level of CD69 in sepsis patients was much higher than those in the normal control group. As compared with the scramble control, miR-25 mimics, and CD69 small interfering RNA (siRNA) downregulated the mRNA and protein expression of CD69, whereas the expression of CD69 mRNA and protein in cells transfected with miR-25 inhibitors was significantly higher as compared with that in the scramble control. In addition, interferonγ production was significantly downregulated in cells transfected with miR-25 inhibitors but notably upregulated in cells transfected with miR-25 mimics or CD69 siRNA.

CONCLUSION

The single-nucleotide polymorphism (SNP; rs41274221) in miR-25 is associated with the risk of sepsis in newborns.

Overexpression of miR-25 is associated with progression and poor prognosis of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a rare but highly aggressive type of malignancy. MicroRNA (miR)-25 has been demonstrated to be involved in the genesis of numerous cancer types. The aim of the present study was to investigate the prognostic value and functional role of miR-25 in CCA. The expression of miR-25 was determined by reverse transcription-quantitative (RT-q)PCR. The association between miR-25 expression and clinicopathological features was analyzed using the χ² test. Kaplan-Meier survival analysis and Cox linear regression were performed to explore the prognostic value of miR-25. The effects of miR-25 on the biological behavior of CCA cells were determined using loss-and gain-of-function experiments in CCA cell lines. Upregulated miR-25 expression was observed in CCA tissues and cell lines compared with that in the respective controls (all P<0.05). Patients with high expression of miR-25 in CCA tissues had a comparatively higher tumor-nodes-metastasis stage (P=0.026), a higher rate of lymph node metastasis (P=0.032) and a shorter overall survival rate (log-rank P=0.022). miR-25 was determined to be an independent prognostic factor for CCA patients (P=0.036). In vitro, transfection with miR-25 inhibitor suppressed cell viability, migration and invasion, while miR-25 mimics had the opposite effect. These results indicated that miR-25 functions as an oncogene and is involved in tumor progression in CCA. miR-25 may serve as a prognostic biomarker and a potential therapeutic target for CCA treatment.

Expression of miR-124 in gastric adenocarcinoma and the effect on proliferation and invasion of gastric adenocarcinoma SCG-7901 cells

Expression of miR-124 in gastric adenocarcinoma cell line SGC-7901 and its effect on biological functions was investigated. Expression of miR-124 in cancer tissues and paracancerous tissues of gastric adenocarcinoma patients was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RT-qPCR was used to detect the expression of miR-124 in human normal gastric epithelial cells GES-1 and gastric adenocarcinoma SGC-7901 cells. Cells in miR-124 group were transfected with miR-124 agomir, cells in NC group were transfected with agomir-negative control sequence and cells in the control group were not transfected. MTT assay was used to detect cell proliferation, and Transwell invasion assay to detect cell invasion ability, and the effect of transfected miR-124 agonist on the proliferation and invasive ability of gastric adenocarcinoma cells was evaluated. RT-qPCR results showed that miR-124 expression was significantly downregulated in gastric adenocarcinoma tumor tissues compared with paracancerous tissues. Compared with cells of normal human gastric epithelial cell line GES-1, the expression of miR-124 human gastric adenocarcinoma SGC-7901 cells was significantly downregulated. At 12 h, there was no significant difference in OD at 490 nm in the three groups (P>0.05). OD (490) in the three groups showed a gradual upward trend. After transfection, proliferation curves of the three groups showed an upward trend, proliferation rate of miR-124 group was significantly lower than that of NC and control groups (P<0.05). The number of invading cells in miR-124 group was significantly lower than that in NC group and control group, but there was no significant difference in the number of cell invasion between the NC and control groups. miR-124 can inhibit the proliferation and invasion of gastric adenocarcinoma cells. Downregulation of miR-124 expression in gastric adenocarcinoma may be closely related to the development of gastric adenocarcinoma.

Association between the SNPs of the TOB1 gene and gastric cancer risk in the Chinese Han population of northeast China

The TOB1 (ErbB-2,1) gene is an anti-proliferative factor that has the potential to regulate cell growth and encodes a member of the transducer of erbB-2/B-cell translocation gene protein. The association between the polymorphisms of the TOB1 gene and gastric cancer (GC) risk is still unclear. In this study, 506 GC cases and 548 healthy controls (HCs) were collected to evaluate the association between the eleven SNPs (rs35220381, rs12950561, rs7221352, rs61482741, rs9303568, rs34700818, rs12949115, rs9903822, rs12601477, rs11656976 and rs4626) of the TOB1 gene and GC risk in the population of northeast China. The results showed that there were significant associations of haplotype GCCTTGC, haplotype ATCTTGG, and haplotype GCCACGC with GC risk (P < 0.05, P < 0.001, and P <0.001, respectively). The association between rs12601477 GA+AA genotypes and GC risk was significant among individuals older than 58 (adjusted OR=1.53, 95% CI=1.05-2.22, P< 0.05). The association between rs4626 AG+GG genotypes and GC risk was significant among individuals older than 58 (adjusted OR=1.54, 95% CI = 1.03-2.28, P<0.05). The rs34700818 CT+TT genotypes were associated with a significantly increased risk of T3-T4 (CT+TT vs CC, adjusted OR=1.71, 95% CI= 1.01-2.88, P<0.05) and TNM stage II (CT+TT vs CC, adjusted OR=2.40, 95% CI =1.27-4.52, P<0.01). The rs61482741 CG+GG genotypes were also associated with a significantly increased risk of T3-T4 (CG+GG vs CC, adjusted OR=1.71, 95% CI = 1.01-2.88, P<0.05) and TNM stage II (CG+GG vs CC, adjusted OR=2.40, 95% CI=1.27-4.52, P<0.01). The results suggest that four SNPs (rs12601477, rs4626, rs34700818 and rs61482741) of the TOB1 gene play an important role in the occurrence and development of GC in the Chinese Han population of northeast China.

A myriad of roles of miR-25 in health and disease

Small non-coding RNAs including microRNAs (miRNAs) have been recently recognized as important regulators of gene expression. MicroRNAs play myriads of roles in physiological processes as well as in the pathogenesis of a number of diseases by translational repression or mRNA destabilization of numerous target genes. The miR-106b-25 cluster is highly conserved in vertebrates and consists of three members including miR-106b, miR-93 and miR-25. MiR-106b and miR-93 share the same seed sequences; however, miR-25 has only a similar seed sequence resulting in different predicted target mRNAs. In this review, we specifically focus on the role of miR-25 in healthy and diseased conditions. Many of miR-25 target mRNAs are involved in biological processes such as cell proliferation, differentiation, and migration, apoptosis, oxidative stress, inflammation, calcium handling, etc. Therefore, it is no surprise that miR-25 has been reported as a key regulator of common cancerous and non-cancerous diseases. MiR-25 plays an important role in the pathogenesis of acute myocardial infarction, left ventricular hypertrophy, heart failure, diabetes mellitus, diabetic nephropathy, tubulointerstitial nephropathy, asthma bronchiale, cerebral ischemia/reperfusion injury, neurodegenerative diseases, schizophrenia, multiple sclerosis, etc. MiR-25 is also a well-described oncogenic miRNA playing a crucial role in the development of many tumor types including brain tumors, lung, breast, ovarian, prostate, thyroid, oesophageal, gastric, colorectal, hepatocellular cancers, etc. In this review, our aim is to discuss the translational therapeutic role of miR-25 in common diseased conditions based on relevant basic research and clinical studies.

Decreased TOB1 expression and increased phosphorylation of nuclear TOB1 promotes gastric cancer

TOB1, a member of the BTG/TOB protein family, inhibits tumor cell proliferation. We previously observed down-regulation and phosphorylation of TOB1 in gastric cancer (GC). Here, we examined the subcellular distribution and clinical significance of TOB1 expression and phosphorylation in GC. Immunohistochemical analysis of 341 primary GC and corresponding normal gastric tissue samples demonstrated that nuclear TOB1 expression was lower in GC than normal tissue (80.4% vs. 92.4%), and decreased nuclear TOB1 expression correlated with high TNM stage. By contrast, phosphorylation of nuclear TOB1 was higher in GC than normal gastric tissue (66.0% vs. 36.4%), and was associated with poorly differentiated and high TNM stage tumors. Patients with intestinal type GC and increased nuclear TOB1 phosphorylation had poor overall survival. Multivariate survival analysis indicated the nuclear concentration of phosphorylated TOB1 was an independent prognostic factor for intestinal type GC. Overexpression of TOB1 containing mutations in its nuclear export signal inhibited GC cell proliferation, migration, and invasion compared to cells expressing TOB1 with the nuclear localization signal. Thus, decreased TOB1 expression and increased phosphorylation of nuclear TOB1 is associated with aggressive tumor behavior and poor prognosis in intestinal type GC. Additionally, TOB1 nuclear retention is critical for its anti-proliferative activity.