Background: Non-small-cell lung cancers (NSCLC) constitute the majority of lung cancer cases, whose risk is associated with environmental factors, such as air pollution, and smoking habits. KRAS mutations are present in about 20% of NSCLC patients, mostly at codon 12 and have been associated to tumor progression and resistance to chemotherapy in many types of cancer. Increasingly evidences seem to highlight that the definition of KRAS status is not sufficient to determine its predictive and/or prognostic role in NSCLC, and indicate that different KRAS mutations could differently impact on crucial cellular processes. An issue still to be addressed is whether different KRAS mutations may modulate cellular metabolism with possible implications on different response to anticancer treatments which specifically inhibit metabolism modulating pathways, such as the PI3K/AKT/mTOR axis.
Methods: We generated from the human NSCLC cell line NCI-H1299 clones overexpressing WT KRAS, and the three most common NSCLC KRAS mutations (G12C, G12V and G12D). The clones were used to determine in vitro response to PI3K, mTOR and AMPK interfering agents. We applied an explorative mass spectrometry-based untargeted metabolomics strategy to characterize the largest possible number of metabolites that might distinguish the different KRAS mutated clones.
Results: KRAS overexpressing clones resulted sensitive to the PI3K inhibitors BKM-120 and PIK-75 and to the PI3K/mTOR dual inhibitor BEZ-235. Metformin (acting on AMPK) did not display a cytotoxic activity on the clones at concentrations below or equal to 1mM. Metabolomics analyses revealed that clones harboring different KRAS mutations at codon 12 had different metabolic remodellings such as different redox buffering system and different glutamine-dependency.
Conclusion: The preliminary findings reported herein indicate that specific KRAS mutations at codon 12 are associated to different metabolomics profiles that might have an impact to the response to anticancer treatments. Combination studies including metformin and PI3K/mTOR interfering agents and more detailed metabolomics analyses are ongoing in order to clarify whether metabolic adaptations dependent on KRAS mutants might account for the behaviour of KRAS overexpressing clones treated with different drugs.
Citation Format: Elisa Caiola, Laura Brunelli, Mirko Marabese, Marina Chiara Garassino, Gabriella Farina, Massimo Broggini, Roberta Pastorelli. Role of KRAS in modulating the metabolomic profile and the response of NSCLC cells to PI3K/mTOR and AMPK interfering agents. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4406. doi:10.1158/1538-7445.AM2014-4406