miRNA-766 induces apoptosis of human colon cancer cells through the p53/Bax signaling pathway by MDM4

miRNAs are closely associated with tumor genesis and development. The present study investigated the role of the expression of miRNA-766 in the survival of patients with colon cancer and the underlying molecular mechanisms. Reverse transcription-quantitative polymerase chain reaction analysis and microarray analysis were used to analyze the expression of miRNA-766. The results revealed that the expression of miRNA-766 was decreased in patients with colon cancer. The overall survival and disease-free survival rates of patients with colon cancer with a high expression of miRNA-766 were prolonged, compared with those with a low expression of miRNA-766. The overexpression of miRNA-766 reduced cell growth and induced apoptosis in colon cancer cells through suppression of the MDM4/p53 pathway. By contrast, the downregulation of miRNA-766 promoted cell growth and reduced apoptosis in colon cancer cells through activation of the MDM4/p53 pathway. The promotion of MDM4 attenuated the anticancer effect of miRNA-766 in colon cancer cells. These results demonstrated that miRNA-766 induced cell apoptosis in human colon cancer through MDM4/p53.

Thymosin α1 treatment reduces hepatic inflammation and inhibits hepatocyte apoptosis in rats with acute liver failure

The present study aimed to evaluate whether thymosin α1 (Tα1) increases survival rates through the improvement of immunofunction and inhibition of hepatocyte apoptosis in rats with acute liver failure (ALF). A total of 25 rats were randomly divided into the control group (CG), the model group (MG) and the treatment group (TG). The CG received an intraperitoneal injection of saline (2 ml). The ALF rat model was established by the intraperitoneal injection of D-galactosamine (700 mg/kg) and lipopolysaccharide (10 µg/kg). The TG received an intraperitoneal injection of Tα1 (0.03 mg/kg) 1 h prior to and 30 min after modeling. The survival rates of the rats were recorded. An additional 63 rats were randomly divided into a CG (n=3), MG (n=30) and TG (n=30). Three rats were sacrificed at 3, 6, 9 and 12 h after establishment of the rat model to detect plasma alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin (TBIL), tumor necrosis factor (TNF)-α and interleukin-10 (IL-10). Liver samples were stained with hematoxylin and eosin and TUNEL, and reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed to detect B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) in liver tissue. The results indicated that the survival rate of the TG was significantly higher compared with that of the MG at 24 h (P<0.05). Plasma ALT, AST and TBIL in the MG and TG increased over time (3–12 h), with ALT, AST and TBIL observed to be significantly lower in the TG compared with the MG at each time-point (P<0.05). Hepatocellular necrosis, hemorrhage and inflammatory cell infiltration of ALF were aggravated over time (3–12 h) in the MG and TG. Notably, in the Tα1-treated rats, the hepatocytes appeared healthier with fewer apoptotic cells compared with those from the MG at the same time-points. Hepatocyte apoptotic index increased in the TG and MG, but was significantly lower in the TG compared with the MG at each time-point (P<0.05) in TUNEL assays. Plasma TNF-α and IL-10 in the MG and TG increased over time (3–12 h), with TNF-α observed to be significantly lower in the TG compared with the MG at each time-point (P<0.05), however, IL-10 was observed to be significantly higher in the TG compared with the MG at each time-point (P<0.05). Bax mRNA expression was significantly lower in the TG compared with the MG at each time-point (P<0.05), whereas Bcl-2 was significantly higher (P<0.05). In conclusion, Tα1 improved survival rates in an ALF rat model by downregulating TNF-α and upregulating IL-10, leading to the attenuation of hepatic inflammation and hepatocyte apoptosis.

Effect of docosahexaenoic acid on traumatic brain injury in rats

The present study aimed to investigate the protective effects of docosahexaenoic acid (DHA) on traumatic brain injury (TBI) in rats. A model of TBI was induced by lateral fluid percussion injury in adult rats and rats were randomly divided into the TBI-model group, TBI-low DHA group and TBI-high DHA group, while other healthy rats were assigned to the sham-operated group. Motor recovery was tested with beam-walking trials at 2, 7 and 15 days post-TBI. Cognitive recovery was tested with Morris water maze trials at 15 days post-TBI. The expression levels of caspase-3, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were measured by western blotting. DHA protected against motor deficits induced by TBI in beam walking tests. All TBI-model groups had longer escape latency and swimming distances than the sham groups. Compared with the TBI-low DHA group, the TBI-high DHA group demonstrated shorter escape latency and swimming distances. DHA inhibited the expression of caspase-3 and the inhibition effect was more obvious at a high dosage. Furthermore, DHA dose-dependently rescued neurons by upregulating the Bcl-2:Bax ratio. DHA supplementation was a viable strategy to mitigate injury from TBI.

Potential impact of (rs 4645878) BAX promoter -248G>A and (rs 1042522) TP53 72Arg>pro polymorphisms on epithelial ovarian cancer patients

BACKGROUND

In India, Epithelial ovarian cancer has emerged as one of the most common malignancies affecting women. Tumor protein 53 (TP53) induces expression of the B cell lymphoma 2-associated X protein (BAX) gene by directly binding to the TP53-binding element in the BAX promoter. Therefore, we hypothesized that single-nucleotide polymorphism of BAX promoter -248G>A and TP53 72Arg>Pro gene may jointly contribute to ovarian cancer risk.

OBJECTIVES

This study aimed at exploring the association of BAX promoter -248G>A and TP53 72Arg>Pro gene polymorphism with risk of developing EOC and its clinicopathological features and to evaluate gene-gene interaction of these two polymorphisms with risk of developing EOC.

MATERIALS

The study was conducted on 70 Epithelial ovarian cancer patients and 70 healthy controls. Genotyping of p53 codon 72 and BAX promoter gene was examined by ASO-PCR and PICA-PCR, respectively. Odds ratios and 95 % confidence intervals were calculated.

RESULTS

We found an increased cancer risk associated with the BAX AA (ORs = 4.1, 95 %, CI = 1.23-13.97) genotype. An increased risk was also associated with the TP53 Pro/Pro (OR = 4.4, 95 % CI = 1.40-13.99) and Arg/Pro genotype (OR = 2.3, 95 % CI = 1.13-4.86). The gene-gene interaction of these polymorphisms increased EOC risk in a more than additive manner (ORs for the presence of both BAX AA and TP53 Arg/Pro genotypes = 8.7, 95 % CI = 1.66-45.48). BAX GG genotype was associated with adverse staging of cancer (P = 0.01).

CONCLUSIONS

The findings suggest that polymorphism of BAX and TP53 genes may be potential genetic modifiers for developing ovarian cancer.