Lung cancer is the leading cause of cancer death in the US with »124,000 new cases annually, and a 5 y survival rate of »16%. Mutant KRAS-driven lung adenocarcinoma (KRAS LADC) is a particularly prevalent and deadly form of lung cancer. Protein kinase Ci (PKCi) is an oncogenic effector of KRAS that activates multiple signaling pathways that stimulate transformed growth and invasion, and maintain a KRAS LADC tumor-initiating cell (TIC) phenotype. PKCi inhibitors used alone and in strategic combination show promise as new therapeutic approaches to treatment of KRAS LADC. These novel drug combinations may improve clinical management of KRAS LADC.KEYWORDS lung adenocarcinoma; oncogenic Kras; Protein Kinase Ciota; therapeutic targeting KRAS mutation is an oncogenic driver required for LADC tumor initiation and maintenance Activating KRAS mutations are detected in approximately 33% of LADC. KRAS mutations are also present in preneoplastic lesions of the lung (atypical alveolar hyperplasias, AAH), suggesting early acquisition during lung neoplasia.1 Genomic sequencing of lung adenomas in situ revealed both regional histological and genomic heterogeneity; however, KRAS mutations were observed uniformly throughout individual lesions, indicating that mutant KRAS drives early tumor cell transformation, selection and evolution.
2Expression of mutant KrasG12D in the mouse lung is sufficient to drive LADC initiation, providing in vivo evidence that KRAS is a key oncogenic driver of LADC initiation.3,4 Interestingly, systemic delivery of KRAS siRNA significantly inhibited tumor growth and metastasis of mutant KRAS LADC tumors, demonstrating a continued dependency on mutant KRAS signaling for tumor maintenance.