Abstract PO018: The development of chemoresistant liver cancer cells to explore visfatin and the IGF-1/IR/Akt axis
Authors: Groll Curissa , Price Ramona Salcedo 
Published: September 2022

Abstract
Background: Obesity is a risk factor for liver cancer a lethal cancer that has increased in incidence and mortality. Understanding how obesity increases the risk for liver cancer progression and chemoresistance is important because of the high prevalence of obesity. In late-stage liver cancer, sorafenib, a multi-kinase inhibitor, is an effective first-line of chemotherapy until resistance emerges. Considering the potential for obesity-related promotion of hepatocellular carcinoma (HCC), there is also a potential link between obesity and HCC Sorafenib resistance. In addition to higher levels of insulin and IGF-1, obese individuals also have higher circulating amounts of adipocytokines such as visfatin, which may have a role in resistance to treatment. The purpose of this study is to develop an in vitro model of chemoresistance to identify strategies to break the obesity-cancer link.Methods: HepG2, Huh7, and SNU-449 liver cancer cells were used to develop sorafenib resistant cells. Cells continuously exposed to sorafenib are referred to as HepG2R, Huh7R, and SNU-449R. Cells were exposed to Sorafenib concentration beginning at 5 µM to 10 µM gradually, over approximately four months. To characterize resistance, cell viability, survival, and protein signaling were analyzed every four weeks. MTT, colony formation, and immunoblot assays were used to determine viability survival and protein signaling. Resistant cells were exposed to the following conditions; control, 80 ng/mL of visfatin, visfatin + 100 µM of HNMPA, visfatin + 500 nM of PPP, visfatin + 10 µM of LY294002, visfatin + 100 µM of HNMPA + 500 nM of PPP.Results: For the first two time points HepG2, SNU-449 and Huh7 cell lines did not demonstrate resistance. Huh7R and HepG2R cells did not differ in proliferation compared to cells not exposed to sorafenib. SNU-449R cells when treated with Sorafenib were more proliferative and increased survival compared to SNU-449 non-resistant cells. HepG2R cells had increased survival and BCL-xL protein expression compared to non-resistant cells. At time point 4, SNU-449R and HepG2R cells demonstrated resistance to sorafenib with increased anti-apoptotic signaling, survival, and cell viability. HUH7 non-resistant and HUH7R cells had no significant differences when treated with Sorafenib or the control. Visfatin increased proliferation compared to cells exposed to visfatin plus inhibitors. Visfatin plus iNAMPT or IR inhibitor decreased proliferation.Conclusion: HepG2 and SNU-449 liver cancer cells that were continuously exposed to Sorafenib resulted in increased proliferation, survival, and anti-apoptotic signaling. Visfatin promoted proliferation and inhibited IR, and iNAMPT inhibition suppressed these effects. Using these cell lines, future studies can identify strategies to sensitize chemoresistance cells to chemotherapy in the context of obesity by inhibiting visfatin ligand or enzyme activity.
Citation Format: Curissa Groll, Ramona Salcedo Price. The development of chemoresistant liver cancer cells to explore visfatin and the IGF-1/IR/Akt axis [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr PO018.