Effect of AXL on cholangiocarcinoma survival and sensitivity to cytotoxic chemotherapy.

Authors

null

Shohei Takaichi

Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN;

Shohei Takaichi , Jennifer L Tomlinson , Mincheng Yu , Amro M Abdelrahman , Nathan W Werneburg , Gregory J Gores , Rory L Smoot

Organizations

Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN; , Department of Surgery, Mayo Clinic, Rochester, MN; , Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN;

Research Funding

No funding received
None.

Background: Cholangiocarcinoma (CCA) is a lethal disease with limited therapeutic options. We have demonstrated the interaction of Src-family kinase LCK with AXL, a TAM receptor tyrosine kinase (RTK), by phosphoproteomic analysis in CCA (J Hepatol 2022). AXL is reported to act as a mechanism of acquired drug resistance in solid cancers. However, the role of AXL in CCA remains to be elucidated. Here, we investigated the significance of AXL expression as a potential therapeutic target in CCA. Methods: We first evaluated the expression levels of AXL in CCA and the associations with patient outcome using publicly available data from The Cancer Genome Atlas (TCGA). Next, to evaluate whether AXL inactivation sensitizes CCA cells to gemcitabine and cisplatin (GemCis) therapy as a standard therapy. AXL downregulation was achieved via siRNA approach and the selective inhibitor bemcentinib. We examined 50% inhibitory concentration (IC50) value of HuCCT1, a well characterized CCA cell line, on GemCis therapy with and without AXL knockdown using CellTiter-Glo cell viability assay. Then we assessed the efficacy of the combinatorial therapy of GemCis and bemcentinib utilizing Calcusyn software. Finally, apoptosis was evaluated by Annexin V assay. In vivo efficacy was assessed using a SB-1 (murine CCA cell line) and syngeneic murine model of CCA in C57Bl/6J mice treated with vehicle, GemCis, bemcentinib, and the combination of GemCis and bemcentinib. Results: In the TCGA cohorts, AXL is significantly expressed in CCA (P < 0.01), and disease-free survival and overall survival in low AXL expression group are significantly longer than those in high AXL expression group (P = 0.04, 0.01). In in vitro study, IC50 value of GemCis was decreased from 685nM to 129nM after AXL knockdown. Synergy effect was observed with the value of CI = 0.17 and Fa = 0.50 in the combinatorial therapy. The combinatorial therapy caused significantly increased apoptosis compared to GemCis or bemcentinib alone (P < 0.01, P < 0.01). In in vivo study, the combinatorial therapy significantly suppressed the tumor growth compared to GemCis or bemcentinib alone (P = 0.04, 0.01). Conclusions: Targeting AXL sensitizes CCA cell lines and preclinical models to standard of care GemCis combinatorial therapy. Our study suggests that the addition of AXL targeted therapy to cytotoxic chemotherapy can increase the response in CCA patients and is a promising combination.

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Abstract Details

Meeting

2023 ASCO Gastrointestinal Cancers Symposium

Session Type

Poster Session

Session Title

Poster Session B: Cancers of the Pancreas, Small Bowel, and Hepatobiliary Tract

Track

Pancreatic Cancer,Hepatobiliary Cancer,Neuroendocrine/Carcinoid,Small Bowel Cancer

Sub Track

Translational Research

Citation

J Clin Oncol 41, 2023 (suppl 4; abstr 591)

DOI

10.1200/JCO.2023.41.4_suppl.591

Abstract #

591

Poster Bd #

F3

Abstract Disclosures