Abstract PR-2: KRAS mutation and amplification status predicts sensitivity to antifolate therapies in non-small cell lung cancer

Autor: Sarah S. Bacus
Rok vydání: 2011
Předmět:
Zdroj: Molecular Cancer Therapeutics. 10:PR-2
ISSN: 1538-8514
1535-7163
Popis: Somatic genetic mutation in the V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) gene has been linked to poor prognosis and resistance to various targeted therapeutics in Non Small Cell Lung Cancer (NSCLC). Therapeutic strategies that target tumors harboring these mutations represent an unmet medical need. In this study, we investigated the relationship between antifolate sensitivity and KRAS mutation/amplification status in NSCLC. Human NSCLC cell lines (KRAS wild type, KRAS mutant non-amplified and KRAS mutant amplified) were treated with Methotrexate (MTX) or Pemetrexed (PEM) and assayed for proliferation after 72h. In these studies, 5 out of 7 KRASwt (wildtype) cells and all KRASmut (mutant) amplified cells showed resistance to MTX treatment (IC50 >10μM). In contrast, growth of all KRASmut non-amplified cell lines studied was inhibited with MTX treatment (IC50 Collectively, these studies identify increased sensitivity to antifolates in KRASmut non-amp NSCLC cell lines. Anti-folate therapies decrease KRAS gene expression in KRASwt and KRASmut cells but do not do so in KRASmut amplified cells. We propose that decreased KRAS gene expression is detrimental to KRASmut cells due to their dependency on this pathway for survival. We also propose that decreases in KRAS gene expression are mechanistically linked to stress (folate inhibition) induced miRNA expression which target KRAS gene expression. Overall, antifolates represent a novel method to target KRAS and as such should be investigated further for use in this subtype of NSCLC. As clinical evidence emerges, it is apparent that both KRAS mutation and amplification status should be considered for patient stratification prior to antifolate treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr PR-2.
Databáze: OpenAIRE