Search

As demonstrated in previous studies, the phosphorylated form of 4E-binding protein 1 (p-4E-BP1) may be a suitable tumor biomarker. The aim of the current study was to examine the expression status of p-4E-BP1 in colorectal cancer (CRC), in order to determine its clinical significance. The present study enrolled 89 patients with CRC that had undergone radical resection. Paired tumor and adjacent normal tissues were evaluated using immunohistochemistry to detect the protein expression of p-4E-BP1 and phosphatase and tensin homolog (PTEN). The study identified 53 cases (59.6%) that exhibited moderate or high expression of p-4E-BP1 in tumor tissues, compared with little or no expression in the adjacent normal tissues. Conversely, PTEN protein expression was markedly lower in CRC compared with adjacent normal tissues. p-4E-BP1 protein upregulation tissues samples was consistent with PTEN downregulation in CRC samples. p-4E-BP1 overexpression was predominant in patients with metastasis to the regional lymph nodes. Moderate/high expression of p-4E-BP1 protein was significantly associated with adverse overall survival (OS) in patients. Statistical analysis using the Cox proportional hazards model, indicated that p-4E-BP1 expression was an independent factor suitable for predicting OS in CRC patients, which was independent of lymph node metastasis. In conclusion, p-4E-BP1 protein expression appears to be upregulated in CRC, suggesting that it may be a suitable biomarker for predicting CRC prognosis. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the effects of small interfering (si)RNA interference of connexin 37 (Cx37) on subcutaneous gastric tumours in mice. Constructed lentiviruses carrying siRNA against Cx37 significantly knocked down Cx37 mRNA and protein expression in vitro. A total of 60 mice with gastric cancer were randomly divided into the Cx37 siRNA group, the mock-siRNA group and the control group. Cx37 siRNA, mock-siRNA and saline were separately injected (with the lentiviruses transfected into the gastric cancer cells). Following six weeks, the Cx37 mRNA expression, Cx37 protein expression and tumor apoptosis were detected using semiquantitative reverse transcription-polymerase chain reaction, western blot analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling, respectively. Six weeks following lentiviral transfection, the Cx37 mRNA levels in the Cx37 siRNA group, mock-siRNA group and saline group decreased to 42, 63 and 67%, respectively (P<0.05). The mock-siRNA group demonstrated no significant change in Cx37 levels compared with the control group. Western blot analysis revealed lower Cx37 protein levels in the Cx37-RNAi group than in the other groups (0.21±0.07 vs. 0.65±0.06 vs. 0.54±0.07), and that the apoptotic index of the Cx37-RNAi group was higher than those of the mock-siRNA and control groups (19.7±5.1 vs. 9.8±6.4 vs. 10.5±7.2%, 11.1±6.9; P<0.05). In conclusion, it was demonstrated that Cx37 siRNA is correlated with gastric cancer. Interference of Cx37 effectively reduces Cx37 mRNA and protein expression and promotes tumour apoptosis. [ABSTRACT FROM AUTHOR]