Abstract 4391: MET is a potential therapeutic target and a candidate for combination therapy with EGFR inhibition in triple-negative/basal-like breast cancer.

Abstract

Abstract Triple-negative breast cancer (TNBC)/basal-like breast cancer (BLBC) are known as poor outcome subtypes with deficiency of targeted molecular therapy. Previous studies showed that MET may play a critical role in the development of TNBC and may be a rational therapeutic target. In order to evaluate MET as a potential therapeutic target for TNBC, we investigated genomic aberration and expression status of MET and evaluated efficacy of MET inhibitor, PHA-665752 in TNBC cell lines. MET protein expression was relatively high in TNBC cell lines. The depletion of MET using small interfering RNA (siRNA) led decreased cell proliferation and migration. PHA-665752 treatment resulted in decreased cell viability, and most of these cell lines were found to be moderately sensitive in their response to PHA-665752. The most resistant cell line, MDA-MB-468, showed exclusively high expression of EGFR, and then EGFR depletion using siRNA induced increased sensitivity to PHA-665752. In our cohort, BLBC was the subtype showing the highest relationship with MET expression among 5 subtypes (77/134, 57.5%, P<0.001). MET expression had a poorer OS (P=0.001) and DFS (P=0.010). Interestingly, TNBC patients with co-expression of MET and EGFR worsen the DFS significantly compared with EGFR expression only. Our findings highly suggest that MET can be a potential therapeutic target in TNBC, and the combined inhibition of MET and EGFR may benefit for the treatment of BLBC patients. Citation Format: Yu Jin Kim, Jong-Sun Choi, Ji-Young Song, Kyungsoo Jung, Ensel Oh, Young Kee Shin, Yoon-La Choi. MET is a potential therapeutic target and a candidate for combination therapy with EGFR inhibition in triple-negative/basal-like breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4391. doi:10.1158/1538-7445.AM2013-4391