Abstract 2178: MET inhibition using SU11274 impairs cellular activities in hepatocellular and Cholangiocarcinomas with high levels of MET and low levels of EGFR expressions.
Authors: Tijeras-Raballand Annemilai , Serrate Camille , Riveiro Maria E. , Serova Maria , Neuzillet Cindy , Martinet Matthieu , Paradis Valérie , Bièche Ivan , Raymond Eric , de Gramont Armand , Faivre Sandrine 
Published: August 2014

Introduction: c-MET pathway is often deregulated in human cancer progression including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CK). Moreover, high level of HGF, and c-MET have been correlated with poor prognosis, aggressiveness and metastasis in HCC and CK (Kaposi-Novak et al., 2006; Miyamoto et al., 2011). We aimed to characterize the expression pattern of MET in HCC/CK specimens, to evaluate the effects of MET inhibition on HCC/CK cell properties, and to identify potential biomarkers of sensitivity and resistance to SU11274.

Methods: SU11274 is a specific inhibitor of overexpressed and activated MET. MET expression was assessed on human paraffin-embedded liver section by IHC. Antiproliferative effects of SU11274 and an EGFR/HER2 inhibitor (lapatinib) were evaluated in human HCC (Sk-Hep1 and its sunitinib-tolerant counterpart SK-Suni) and CK (Mz-ch-A1, Mz-ch-A2, and SK-CH) cell lines using MTT assay. mRNA expression and protein levels were assessed by qRT-PCR and Western blot, respectively. Cell motility was investigated by wound-healing and matrigel invasion assays.

Results: MET expression level was higher in HCC and CK tumor samples than adjacent normal liver tissue. Characterization of cell lines showed that MET-protein and -mRNA expression were detectable in all cell lines, Mz-ch-A1, Mz-ch-A2 and SK-HEP1 expressing higher MET levels (high-MET) compared to the other cell lines (low-MET). HGF-induced MET activation was associated with differential pattern of p-METTyr1234/35, p-GAB1, p-ERK1/2, and p-AKTser473 between high-MET and low-MET cell lines. We showed that SU11274 inhibits HGF-induced downstream signaling in all HCC and CK cell lines at 0.5-2μM. However, antiproliferative effects were only observed in the high-MET cell lines; inhibition rates were 83%, 53% and 48% in Mz-chA-1, Mz-chA-2 and SK-Hep1, respectively. Interestingly, SU11274 also potently decreased HGF-dependent cell motility (75-90% inhibition) in high-MET cells but not in low-MET cells. Since cells with low-MET showed high EGFR expression, we tested the EGFR/HER2 inhibitor lapatinib on cell proliferation. In contrast to SU11274, lapatinib inhibited proliferation in low-MET/high-EGFR cells (64% and 60% inhibition rate in SK-CH and SK-Suni, respectively) but not in high-MET/low-EGFR cell lines. Complementary results with a sorafenib-tolerant cell line, SK-sora and two intra-hepatic cholangiocarcinoma cell lines will be added.

Conclusion: In HCC and CK cells, inhibition of MET-signaling by SU11274 results in decreased cell proliferation, motility and invasion restricted to high-MET/low-EGFR cell lines. Thus, high-MET/low EGFR HCC and CK might be the candidate tumor types to evaluate novel MET inhibitors, whereas low-MET/high-EGFR HCC and CK may be preferentially tested for EGFR pathway inhibition.

Citation Format: Annemilai Tijeras-Raballand, Camille Serrate, Maria E. Riveiro, Maria Serova, Cindy Neuzillet, Matthieu Martinet, Valérie Paradis, Ivan Bièche, Eric Raymond, Armand de Gramont, Sandrine Faivre. MET inhibition using SU11274 impairs cellular activities in hepatocellular and Cholangiocarcinomas with high levels of MET and low levels of EGFR expressions. [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 2178. doi:10.1158/1538-7445.AM2013-2178