It is important to select appropriate targeted therapies for subgroups of patients with lung adenocarcinoma who have specific gene alterations. This prospective study was a multicenter project conducted in Taiwan for assessment of lung adenocarcinoma genetic tests. Five oncogenic drivers, including EGFR, KRAS, BRAF, HER2 and EML4-ALK fusion mutations, were tested. EGFR, KRAS, BRAF and HER2 mutations were assessed by MALDI-TOF MS (Cohort 1). EML4-ALK translocation was tested by Ventana method in EGFR-wild type patients (Cohort 2). From August 2011 to November 2013, a total of 1772 patients with lung adenocarcinoma were enrolled. In Cohort 1 analysis, EGFR, KRAS, HER2 and BRAF mutations were identified in 987 (55.7%), 93 (5.2%), 36 (2.0%) and 12 (0.7%) patients, respectively. Most of these mutations were mutually exclusive, except for co-mutations in seven patients (3 with EGFR + KRAS, 3 with EGFR + HER2 and 1 with KRAS + BRAF). In Cohort 2 analysis, 29 of 295 EGFR-wild type patients (9.8%) were positive for EML4-ALK translocation. EGFR mutations were more common in female patients and non-smokers and KRAS mutations were more common in male patients and smokers. Gender and smoking status were not correlated significantly with HER2, BRAF and EML4-ALK mutations. EML4-ALK translocation was more common in patients with younger age. This was the first study in Taiwan to explore the incidence of five oncogenic drivers in patients with lung adenocarcinoma and the results could be valuable for physicians in consideration of targeted therapy and inclusion of clinical trials.
Inactivation of p53 by human papillomavirus 16/18 E6 plays a crucial role in cervical tumorigenesis. To investigate the involvement of HPV16/18 in lung tumorigenesis, the association between HPV16 or HPV18 E6 and p53 protein expression in 122 lung tumors was evaluated by immunohistochemistry, and data showed that HPV16/18 E6 expression correlated inversely with p53 expression, which was further confirmed by tissue in situ immunostaining. Real-time reverse transcription-PCR analysis indicated that E6-positive tumors had lower p21WAF1/CIP1 and mdm2 mRNA levels than E6-negative tumors. To elucidate the role of E6 in p53 inactivation, we successfully established lung adenocarcinoma cell lines with or without HPV16 infection from patients' pleural effusions. Western blotting showed that E6 protein was indeed expressed in HPV16-infected cells and a lower level of p53 protein was observed in E6-positive cells compared with E6-negative cells. Moreover, the levels of p21WAF1/CIP1 and mdm2 mRNA in E6-positive cells were lower than in E6-negative cells. The interaction of E6 with p53 protein was revealed by immunoprecipitation assay showing that p53 could be inactivated by E6 protein. Conversely, p53 proteins and p21WAF1/CIP1 and mdm2 mRNA expressions were restored in E6-knockdown cells by RNA interference compared with control cells. These results reveal that HPV16/18 E6 may be partially involved in p53 inactivation to down-regulate p21WAF1/CIP1 and mdm2 transcription. In conclusion, HPV16/18 E6 is indeed expressed in HPV DNA–positive lung tumors and is involved in p53 inactivation to contributing to HPV-mediated lung tumorigenesis. [Cancer Res 2007;67(22):10686–93]
Autophagy is a self-digestive process that degrades the cytoplasmic constituents. Immunomodulatory protein, one major bioactive component of Ganoderma, has antitumor activity. In this study, recomb...
This study aimed to challenge chemoresistance by curcumin (CUR) with drug-selected human lung cancer A549 sublines that continuously proliferate in the present of docetaxel (DOC) and vincristine (VCR). Their sensitivities to CUR were measured by MTT assay and the particular intracellular reactive oxygen species (ROS) was detected by fluorescence activated cell sorting (FACS) analysis. Apoptosis was analyzed by Annexin V assay of the flow cytometry. Inhibitors and RNA interference were used to examine the signaling pathway regulated by the kinases. The obtained data demonstrated that CUR induces chemoresistant cell apoptosis by generating ROS and application of N-acetylcysteine (NAC) blocks ROS production, resulting in apoptosis suppression. Phosphorylation of extracellular regulated kinase (ERK), p38 MAPK, and eIF-2α were increased but c-Jun N-terminal kinase (JNK) did not increase when chemoresistant cells were treated with CUR. Downregulation of ERK and p38 MAPK phosphorylation by their inhibitors had no effect on CUR-induced apoptosis. Interestingly, the knockdown of p38 MAPK with shRNA significantly reduced CUR-induced apoptosis on the chemoresistant sublines. Phosphorylation of the eIF-2α protein was inhibited when p38 MAPK was knocked down in DOC-resistant A549 cells, but a high level of phosphorylated eIF-2α protein remained on the VCR-resistant A549 cells when p38 MAPK was knocked down. These data confirmed that CUR-augmented ROS potently induced apoptosis via upregulated p38 MAPK phosphorylation. Therefore, activated p38 MAPK is considered a pro-apoptotic signal for CUR-induced apoptosis of chemoresistant human lung cancer cells.