Construction of Clinically Relevant Non‐Small Cell Lung Cancer Model in Athymic Nude Mice using 3D Spheroids of A549‐iRFP Cells

Abstract

BackgroundLung cancer is the top killer cancer in the US. Monolayer cultures of lung cancer cells and their animal xenografts are major models for testing therapeutic modalities against lung cancer. Injection of suspended cancer cells into the lung is one of the most common approach to build an orthotopic lung cancer model but carry several major disadvantages, including the omission of a primary solid tumor and the artificial metastasis generated from the premature leakage of the injected cell suspension [1]. All such drawbacks could severely mislead the development of new therapies against lung cancer. Compared to cell monolayers or cell suspensions in culture, three‐dimension (3D) cancer cell spheroids better mimic the tumor microenvironment [2].PurposeThe purpose of this study is to build a more clinically relevant, orthotopic lung cancer model by inoculating 3D spheroids of lung cancer cells into the mouse lung.MethodThe 3D spheroids were cultured by seeding human lung cancer cell line A549‐iRFP in corning 96 multicellular microplate. The cells stably expressed infrared fluorescent protein, whose signal was detected on Odyssey CLx imaging machine (λex = 685 nm, λem = 700 nm) to image the tumor growth in vivo. Tumor inoculation was performed by transpleural surgery on the left side of the athymic nude mice [3].ResultsThe fluorescence of the spheroids was proportional to their volume and viability (R2=0.9845 and 0.9305). Early in Day 7, the mice inoculated with the 3D spheroids (right 2 and 3) showed confined tumor growth at the inoculation side of the lung whereas those inoculated with cancer cell suspension (left 1) displayed perfused signal on both sides of the lung, indicating premature leakage of the inoculated cancer cells.ConclusionThe mice inoculated with the cancer cell suspension displayed artificial metastasis due to premature leakage of the injected cells inside the lung, which decreased its clinical relevance of mimicking lung cancer progression. In contrast, mice inoculated with the 3D cancer cell spheroids better mimic the progression of non‐small cell lung cancer in clinic.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.