High throughput chemotherapeutic drug screening system for gastric cancer: cure-GA

Abstract

To discover clinically applicable anticancer drugs and predict therapeutic response for advanced gastric cancer, we developed a high-throughput drug (HTD) screening system that could rapidly evaluate drug reactivity using 3D cultured primary cells derived from gastric cancer (GC) patients. Primary cancer cells were isolated from fresh surgical specimens that resected from 143 GC patients using Gentle Max tissue dissociation system. Primary cells were mixed with Matrigel, and placed on a micropillar for three-dimensional (3D) culture. After the primary cells were stabilized in the complete culture medium (CCM) than added various chemotherapeutic drugs containing 5-FU, Oxaliplatin, and Paclitaxel in CCM and incubated for 7 days. Cell viability was determined through calcein staining and quantified scanned images. The IC50 for each drug was calculated by a sigmoidal dose-response curve, using the GraphPad Prism 9 program. The average weight of gastric cancer tissue used in the experiment was 300 mg (75 mg ~ 1930 mg), and the average number of dissociated viable cells for each tissue was 3.9 × 10^6 cells/case. About 2.4 × 10^5 live cell was required per drug, we were able to obtain an average of 6.4 (Min.2, Max 14) drug reactivity data per tissue using the HTD screening system. GC tissues obtained from the operating room were dissociated within 16 hours and then loaded into the HTS system within 3 hours. Cells were stabilized for 1 day in 3D culture plate and exposed to the drug for 7 days, and then data reports were made within 3 days. As a result, it was possible to obtain within 14 days from fresh surgical GC tissue to drug response data. Additionally, we confirmed that 3D cultured primary cells derived from GC tissues consistently preserved primary characters using IHC. Similar to their parental cancer tissue, GC 3D cultured primary cells derived from adenocarcinoma large glandular patterns and retain the expression of some marker proteins. In this study, we evaluated the drug response data for 101 cases (success rate 71%; 101/143) to 5-FU, Oxaliplatin, and Palitaxel, etc. using the HTD screening system and it was confirmed that individual patient had a difference response to each drug. Here we established the HTD screening system using 3D cultured GC patient derived primary cells. The advantages of this system were that it is the first model system that directly used patient-derived primary cells for drug screening, and it can rapidly evaluate drug reactivity to various anticancer drugs within 10 days. The HTD screening system based on patient-derived primary cells can provide that information to predict drug response and allow for finding more appropriate therapy for each patient.