Enhanced oxidative stress and the glycolytic switch in superficial urothelial carcinoma of urinary bladder

AbstractObjectiveTo examine whether oxidative stress and the glycolytic switch are correlated to tumor grading, tumor recurrence, and disease progression in urothelial carcinoma (UC) of the urinary bladder (UB).MethodsAll surgical specimens obtained from 27 patients (each containing their UC and normal tissues of UB) were subjected to a pathological examination by computerized tomography, and a portion of each specimen was used for the analysis of molecular biomarkers. The mRNA expression levels of pyruvate dehydrogenase kinase-1 (PDK1), hypoxia-inducible factor 1 alpha (HIF-1α), lactate dehydrogenase A (LDHA), pyruvate dehydrogenase, and glucose transporter protein 1 (Glut-1) were measured using TaqMan-based real-time quantitative polymerase chain reaction. In addition, 8-hydroxy-2-deoxyguanosine (8-OHdG) and the mitochondrial DNA (mtDNA) copy number were also determined.ResultsThe 8-OHdG content and glycolytic genes expression were higher in UC of the UB than those in the normal tissues of UB, whereas the mtDNA copy number was depleted. According to the multivariate analysis, patients with Grade 3 tumors had higher expression levels of HIF-1α, LDHA, and Glut-1 than those with Grades 1 and 2 tumors. In addition, patients with locally recurrent tumors had a higher expression of HIF-1α and LDHA than those with nonrecurrent tumors. Furthermore, patients under disease progression had higher levels of HIF-1α and PDK1 than those not under disease progression.ConclusionsUC of the UB manifested that the glycolytic phenotype would reflect the Warburg effect. We suggest that the molecular mechanism in the regulation of glycolytic switch in UC of the UB might provide a specific biomarker for the future development of cancer diagnosis

The role of cytochrome c oxidase subunit Va in non-small cell lung carcinoma cells: association with migration, invasion and prediction of distant metastasis

BACKGROUND: Lung cancer is one of the most lethal malignancies worldwide, but useful biomarkers of lung cancer are still insufficient. The aim of this study is to identify some membrane-bound protein(s) associated with migration and invasion in human non-small cell lung cancer (NSCLC) cells. METHODS: We classified four NSCLC cell lines into high and low migration/invasion groups by Transwell and Matrigel assays. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), we identified 10 membrane-associated proteins being significantly overexpressed in the high migration/invasion group. The expression of the target protein in the four NSCLC cell lines was then confirmed by reverse transcription polymerase chain reaction (RT-PCR), western blot and immunostaining. RNA interference technique was applied to observe the influence of the target protein on migration and invasion. Gelatin zymography was also performed to evaluate the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Expression condition of the target protein on surgical specimens was further examined by immunohistochemical staining and the clinicopathologic data were analyzed. RESULTS: We identified a mitochondria-bound protein cytochrome c oxidase subunit Va (COX Va) because of its abundant presence found exclusively in tumorous areas. We also demonstrated that migration and invasion of NSCLC cells decreased substantially after knocking down COX Va by siRNA. Meanwhile, we found a positive correlation between COX Va expression, Bcl-2 expression and activities of MMP-2 and MMP-9 in NSCLC cells. Immunohistochemical staining of surgically resected lung adenocarcinomas in 250 consecutive patients revealed that strong COX Va expression was found in 54.8% (137/250) of patients and correlated positively with the status of lymph node metastasis (P = 0.032). Furthermore, strong COX Va expression was associated with the presence of distant metastasis (P = 0.033). CONCLUSIONS: Our current study showed that COX Va may play a role in migration and invasion of NSCLC cells and can be used as a biomarker to predict aggressiveness of NSCLC

Resveratrol Impedes the Stemness, Epithelial-Mesenchymal Transition, and Metabolic Reprogramming of Cancer Stem Cells in Nasopharyngeal Carcinoma through p53 Activation

Cancer stem cells (CSCs) are able to self-renew and are refractory to cancer treatment. To investigate the effects of resveratrol on CSCs of nasopharyngeal carcinoma (NPC), we employed a behavior selection strategy to isolate CSCs based on radioresistance, chemoresistance, and tumor sphere formation ability. These NPC CSCs displayed stem cell properties and underwent metabolic shift to predominately rely on glycolysis for energy supply. Intriguingly, we found that resveratrol turned off the metabolic switch, increased the reactive oxygen species (ROS) level, and depolarized mitochondrial membranes. These alterations in metabolism occurred concomitantly with the suppression of CSC properties including resistance to therapy, self-renewal capacity, tumor initiation capacity, and metastatic potential in NPC CSCs. We found that resveratrol impeded CSC properties through the activation of p53 and this effect could be reversed by knockdown of p53. Furthermore, resveratrol suppressed the stemness and EMT through reactivating p53 and inducing miR-145 and miR-200c, which were downregulated in NPC CSCs. In conclusion, we demonstrated that resveratrol employed the p53 pathway in regulating stemness, EMT, and metabolic reprogramming. Further investigation of the molecular mechanism of p53 activation by resveratrol may provide useful information for the development of novel therapies for cancer treatment through targeting to CSCs