LAUSR

Intrahepatic cholangiocarcinoma (iCCA) is a subtype of biliary malignancy that arises along the peripheral bile duct epithelium. Given its limited and inefficacious treatment options, the mortality rate of iCCA remains high and thus a novel therapeutic strategy is urgently needed. The concept of cancer stem cells (CSCs) explains a subpopulation of cancer cells that possesses self-renewal and differentiation capacities. These CSCs become the culprit for cancer metastasis, cancer recurrence and chemotherapeutic resistance, making them promising targets for cancer treatment. The propose of this study is to identify the signaling pathways crucial for the survival of iCCA with stemness characteristics. Gene expression analysis on a dataset of Thai iCCA patients (n=91) showed that iCCA tumors are enriched in the Adult Stem Cell (ASC) signature which are the shared characteristics among the epithelial-derived cancer with stemness characteristics. Although iCCA cells exhibit some degree of enrichment in stem cells markers when compared with cholangiocyte cells, further upregulation of stem cell-related genes, e.g. Nanog, Oct3/4, Sox2, and Sox9, were found in iCCA cells grown as 3D tumorspheres. A kinase inhibitor screening library was then performed on iCCA tumorspheres. Our initial screening demonstrated that 11 out of the top 50 kinase inhibitors that effectively decrease viability of iCCA tumorspheres belongs to the insulin-like growth factor-1 receptor (IGF-1R)/phosphoinositide-3-kinase (PI3K)/protein kinase B (PKB/AKT) axis. Additionally, these inhibitors increase cell apoptosis, judged by the caspase 3/7 activity, within iCCA tumorspheres. Conversely, IGF-1 treatment which is sufficient to induce activation of IGF-1R and AKT also enhances cell viability and decrease cell apoptosis in iCCA. Taken together, our data demonstrate that IGF-1R/PI3K/AKT axis is crucial for survival of iCCA cells with stemness characteristics and this pathway could be a potential therapeutic target in iCCA. Citation Format: Chotirat Rattanasinchai, Chidchanok Chornkrathok, Donlaporn Sriphan, Panida Navasumrit, Mathuros Ruchirawat. Kinase library screening identifies IGF-1R/PI3K/AKT axis as a crucial pathway for survival of intrahepatic cholangiocarcinoma cells with stemness characteristics. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5806.