Development of target therapy against KRAS mutant lung cancer stratified by EMT status.

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07164
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Tumor therapeutics
• Research Institution: Aichi Cancer Center Research Institute (2017-2018); Kanazawa University (2016)
• Principal Investigator: EBI Hiromichi 愛知県がんセンター(研究所), がん標的治療TR分野, 分野長 (00645145)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: KRAS / EMT / feedback / MEK

Outline of Final Research Achievements

Whereas the mitogen-activated protein kinase (MAPK) is a well-known effector pathway of KRAS, blocking this pathway with clinically-available MAPK inhibitors is relatively ineffective. We identified that epithelial-to-mesenchymal transition (EMT) rewires the expression of receptor tyrosine kinases, leading to differential feedback activation of the MAPK pathway following MEK inhibition. In epithelial-like KRAS mutant lung cancers, this feedback was attributed to ERBB3. In contrast, in mesenchymal-like KRAS mutant lung cancers, FGFR1 was dominantly expressed but suppressed by the negative regulator sprouty proteins; MEK inhibition led to de-repression of SPRY4 and subsequent FGFR1-mediated re-activation of MEK. Therapeutically, the combination of MEK inhibitor and FGFR inhibitor induced cell death in vitro and tumor regressions in vivo. We established the rationale and a therapeutic approach to treat KRAS mutant lung cancers effectively.

Free Research Field

腫瘍内科学、標的治療開発

Academic Significance and Societal Importance of the Research Achievements

本研究課題を通し、KRAS変異肺がんが上皮間葉移行状態により2種類に分類されることを初めて示した。さらに、それぞれのKRAS変異肺がんに優位に発現している受容体をMEKとともに阻害することにより、KRAS変異肺がんを治療できる可能性を示した。MEK阻害薬単剤では治療効果が不十分であることがこれまでの臨床試験の結果明らかとなっており、本研究は今後の臨床開発の方向性を示すとともに、KRAS変異肺がんに対し個別化医療を行える可能性を示している。本研究の成果は米国癌学会雑誌（Cancer Discovery）に掲載された。