Mutations in genes such as KRAS, NRAS, BRAF and PIK3CA have become an important part of colorectal carcinoma evaluation. The aim of this study was to screen for mutations in these genes in Chinese patients with colorectal cancer (CRC) and to explore their correlations with certain clinicopathological parameters. We tested mutations in the KRAS (exons 2, 3 and 4), NRAS (exons 2, 3 and 4), PIK3CA (exon 20) and BRAF (exon 15) genes using reverse transcriptase-polymerase chain reaction (RT-PCR) and Sanger sequencing in a large cohort of 1,110 Chinese CRC patients who underwent surgical resection at one of three major teaching hospitals located in different regions of China. The prevalence rates of KRAS, NRAS, BRAF and PIK3CA mutations were 45.4%, 3.9%, 3.1% and 3.5%, respectively. Mutant KRAS was associated with the mucinous subtype and greater differentiation, while mutant BRAF was associated with right-sided tumors and poorer differentiation. Our results revealed differences in the genetic profiles of KRAS, NRAS, PIK3CA and BRAF at mutation hotspots between Chinese CRC patients and those of Western countries, while some of these gene features were shared among patients from other Asian countries.

No abstract

Background: Anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) rearrangements represent two most frequent fusion targets in lung adenocarcinoma. Our study was intended to explore the clinicopathological characteristics, coexistence and treatment of ALK/ROS1-rearranged patients of lung adenocarcinoma without epidermal growth factor receptor (EGFR) mutation. Methods:Patients with wild-type EGFR mutation were screened for ALK/ROS1 at four domestic hospitals. ALK/ROS1 rearrangements were detected by reverse transcription-polymerase chain reaction (RT-PCR). Progression-free survival (PFS) curve was plotted with the Kaplan-Meier method.Results: Among 732 eligible cases, ALK and ROS1 rearrangements were detected in 89 (12.2%) and 32 (4.4%) patients respectively. One patient harbored coexisting ALK/ROS1 fusion. Both ALK and ROS1-positive phenotypes were predominantly detected in younger non-smokers. More ALK/ROS1-rearranged patients were correlated with the expressions of TTF1, napsin A and solid predominant adenocarcinoma subtype. Thirty-three ALK and six ROS1 rearrangement patients received crizotinib treatment at an advanced stage. The median PFS was 9.5 months for ALK-positive patients and it was not attained in ROS1-rearranged counterparts. Conclusions:The frequency of ALK and ROS1 rearrangements is elevated in EGFR-wild-type patients and the phenomenon of coexisting ALK/ROS1 has remained extremely rare. The rearrangements of ALK/ ROS1 are correlated with age, smoking status, expressions of TTF1 & napsin A and solid predominant adenocarcinoma subtype.

Lung cancer is the leading cause of cancer-related deaths in the world, and non-small cell lung carcinomas (NSCLC) account for 85 % of lung cancer cases. Despite enormous achievement in the treatment of NSCLC, the molecular mechanisms underlying the pathogenesis are largely unknown. The current study was designed to evaluate the role of miR-155 in NSCLC cell proliferation and to explore the possible molecular mechanisms. We found that miR-155 expression was increased in NSCLC tissues and cell lines. The increase of miR-155 significantly increased A549 cell proliferation, decreased S phase cell population and increased G2/M phase cell population. Decrease of miR-155 expression markedly inhibited cell proliferation, increased S phase cell population, and decreased G2/M phase cell population. Increase of miR-155 significantly decreased forkhead box protein O1 (FoxO1) 3'UTR luciferase activity and expression and decrease of miR-155 notably increased FoxO1 expression. Overexpression of FoxO1 significantly inhibited miR-155-exerted increase of cell proliferation and G2/M cell population. Downregulation of FoxO1 by siRNAs significantly promoted cell proliferation, decreased S phase cell numbers, and increased G2/M cell population. Downregulation of FoxO1 markedly increased ROS level, as reflected by increased DHE staining. Moreover, when N-acetylcysteine was present, increase of cell proliferation induced by downregulation of FoxO1, and upregulation of miR-155 was significantly inhibited. In conclusion, we found that miR-155 promoted NSCLC cell proliferation through inhibition of FoxO1 and the subsequent increase of ROS generation. Our findings highlight miR-155/FoxO1/ROS axis as a novel therapeutic target for the inhibition of NSCLC growth.