Esophageal squamous cell carcinoma (ESCC) is the most common histological subtype of esophageal cancer and one of the most aggressive types of malignancy, with a high rate of mortality. Early diagnosis and treatment may improve the prognosis of ESCC and, thus, survival rates. As a significant tumor suppressor, p53 is closely associated with apoptosis and the differentiation of cancer cells. The present study evaluated the expression levels of the p53 protein and the clinical significance in patients presenting with ESCC. The p53 protein expression level of 64 paired ESCC and tumor-adjacent normal tissues was evaluated using western blot analysis. In addition, immunohistochemistry (IHC) was performed to detect the p53 expression level in specimens from 118 paraffin-embedded cancerous tissues. The correlation of the p53 expression level with the clinicopathological parameters and prognosis of the ESCC patients was also analyzed. The p53 protein was identified to be highly expressed in the ESCC tissue, with western blot analysis demonstrating that the expression level of p53 in the cancerous tissue was 1.89 times that of the tumor-adjacent normal tissue (P<0.001); furthermore, IHC indicated that there was a marked positive expression of p53 in the ESCC tissue (49.15%). The expression level of p53 protein was identified to be significantly correlated with the tumor grade (P<0.001), N stage (P=0.010). Additionally, the higher level of p53 expression was found to be associated with a poor survival rate in the ESCC patients (P=0.0404). The univariate analysis showed that the survival time of patients was significantly correlated with the T stage (RR=3.886, P<0.001), N stage (lymph node metastasis; RR=3.620, P<0.001) and TNM stage (RR=3.576, P<0.001). Furthermore, the multivariate analysis revealed that the T stage (RR=3.988, P<0.001) and N stage (RR=4.240, P=0.004) significantly influenced the overall survival of the ESCC patients.

ATP-dependent Lon protease within mitochondrial matrix contributes to the degradation of abnormal proteins. The oxidative or hypoxic stress which represents the stress phenotype of cancer leads to up-regulation of Lon. However, the role of Lon in bladder cancer remains undefined. Here, we found that Lon expression in bladder cancer tissues was significantly higher than those in noncancerous tissues; down-regulation of Lon in bladder cancer cells significantly blocked cancer cell proliferation via suppression c-Jun N-terminal kinase (JNK) phosphorylation due to decreased reactive oxygen species (ROS) production and enhanced the sensitivity of bladder cancer cells to chemotherapeutic agents by promoting apoptosis. We further found that Lon down-regulation in bladder cancer cells decreased cellular bioenergetics as determined by measuring aerobic respiration and glycolysis using extracellular flux analyzer. The tissue microarray (TMA) results showed that high expression of Lon was related to the T and TNM stage, as well as histological grade of bladder cancer patients. We also demonstrated that Lon was an independent prognostic factor for overall survival of bladder cancer. Taken together, our data suggest that Lon could serve as a potential diagnostic biomarker and therapeutic target for treatment of bladder cancer, as well as for prediction of the effectiveness of chemotherapy.

The long non-coding RNA taurine up-regulated gene 1 (TUG1) has been shown to be dysregulated in various types of malignant cancer; however, its underlying mechanism of action has not been fully elucidated. The present study aimed to investigate the biological role and clinical significance of TUG1 in the progression of colorectal cancer (CRC). A reverse transcription-quantitative polymerase chain reaction assay was used to evaluate TUG1 expression in tissues from patients with CRC. The effect of TUG1 on cell viability of CRC cells using MTT assay. The influence of TUG1 on tumorigenesis was monitored using an xenograft model. The status of the Wnt/β-catenin signaling pathway was evaluated using immunofluorescence, western blotting and luciferase reporter assays. The results demonstrated that the expression of TUG1 was positively associated with the pathological grade and clinical stage of CRC patients. Knockdown of TUG1 inhibited the proliferation of CRC cells and attenuated the activity of Wnt/β-catenin pathway in CRC cells. In addition, TUG1 knockdown inhibited the tumorigenicity in the CRC xenograft model, as well as the nuclear localization of β-catenin and downstream gene transcription. Taken together, the data of the present study highlighted the pivotal role of the TUG1-Wnt/β-catenin signaling pathway in CRC, which could be targeted to improve the therapeutic efficacy of CRC.