Mitochondrial transcription factor A (TFAM) is essential for the replication, transcription and maintenance of mitochondrial DNA (mtDNA). The role of TFAM in non-small cell lung cancer (NSCLC) remains largely unknown. Herein, we report that downregulation of TFAM in NSCLC cells resulted in cell cycle arrest at G1 phase and significantly blocked NSCLC cell growth and migration through the activation of reactive oxygen species (ROS)-induced c-Jun amino-terminal kinase(JNK)/p38 MAPK signaling and decreased cellular bioenergetics. We further found that TFAM downregulation in NSCLC cells led to increased apoptotic cell death and enhanced the sensitivity of NSCLC cells to cisplatin. Tissue microarray (TMA) data showed that elevated expression of TFAM was related to the histological grade and TNM stage of NSCLC patients. We also demonstrated that TFAM is an independent prognostic factor for overall survival of NSCLC patients. Taken together, our findings suggest that TFAM could serve as a potential diagnostic biomarker and molecular target for the treatment of NSCLC, as well as for prediction of the effectiveness of chemotherapy.

Background: Definitive early-stage diagnosis of severe acute respiratory syndrome (SARS) is important despite the number of laboratory tests that have been developed to complement clinical features and epidemiologic data in case definition. Pathologic changes in response to viral infection might be reflected in proteomic patterns in sera of SARS patients. Methods: We developed a mass spectrometric decision tree classification algorithm using surface-enhanced la-

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.

Non-small cell lung cancer (NSCLC) accounts for approximately 80-85% of all lung cancer cases. Cigarette smoking is the number one risk factor which is attributed to more than four out of five cases of lung cancers. The prognostic impact of cell cycle regulation-associated tumor suppressors including p53 and p21 for NSCLC is still controversial. In the present study, we examined p53 and p21 expression using immunoblotting in tumor and adjacent non-cancerous tissues from NSCLC patients. Moreover, tissue microarrays (TMAs) including 150 specimens was used to examine p53 and p21 expression by immunohistochemical staining (IHC). The association between p53/p21 and various clinicopathological characteristics was evaluated. Kaplan-Meier overall survival was used to analyze the association between p53/p21 expression and prognosis of NSCLC patients, as well as the association of cigarette smoking with p53/p21 expression and prognosis. The results of the immunoblotting showed that expression of p53 and p21 in tumor tissues was significantly higher than that in the matched adjacent non-cancerous tissues (P<0.001 and P<0.05, respectively). The IHC results showed that 50.67% of the cases had high expression of p21; however, the percentage of patients having high expression of p53 was 31.3%. Univariate and Cox regression models were used to evaluate the factors related to prognosis with p53 and p21 expression. Multivariate analysis indicated that p53 expression was an independent prognostic factor for NSCLC (P=0.005), while p21 could not serve as an independent prognostic factor (P=0.123). In addition, smoking history was closely related to lung cancer risk (P=0.041), but could not be an independent assessment factor (P=0.740). In this study, we further demonstrated the association of p53/p21 expression and cigarette smoking. Our results suggest that cigarette smoking and overexpression of p53 or p21 are associated with poor prognosis. The combination of p53/p21 expression and smoking history may be a useful biomarker for tumor progression and prognosis of NSCLC patients.