English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

K-rasis frequently mutated in lung adenocarcinomas. Recent discovery that wild-type K-rasis tumor suppressive in the lung raises a question: how is mutant K-rasaggressively oncogenic? We hypothesized that mutant K-ras might lead to generation of reactive oxygen species (ROS) and DNA damage, contributing to malignant transformation. We stably transfected human mutant K-ras  V12into non-transformed peripheral mouse lung epithelial cells (E10 line). Constitutively active mutant K-ras  V12in E10 cells led to a highly significant (P&lt; 0.001) increased level of peroxides, and a corresponding increase in the amount of DNA strand-break damage, compared with the parental line E10 and the vector control. Levels of superoxide were not increased, suggesting a direct source of peroxides, such as cyclooxygenase-2 (COX-2). COX-2 protein and activity measured as prostaglandin E2level were up-regulated in cells expressing mutant K-rasV12; COX-2 activity correlated with K-ras activity (K-ras p21-GTP). Both peroxide generation and DNA single strand breaks were significantly reduced by pre-treatment with COX-2-specific inhibitor SC 58125, confirming COX-2 as the source of the ROS. COX-2 has been repeatedly implicated in lung cancer, and is known to be regulated by ras and to release ROS. Our data suggest that up-regulation of COX-2, with a consequent increase in peroxides and DNA damage, contributes to the dominant oncogenicity of mutant K-ras.

Mutant K- ras V12 increases COX-2, peroxides and DNA damage in lung cells