Effect of Matrix Stiffness and Hepatocyte Growth Factor on Small Cell Lung Cancer Cells in Decellularized Extracellular Matrix-Based Hydrogels.

Small cell lung cancer (SCLC) is one of lethal cancers resulting in very low 5-year-survival rate. Although its clinical treatment largely relies on chemotherapy, SCLC cell physiology in three-dimenstional (3D) matrix has been less explored. In this work, the tumor microenvironment is reconstructed with decellularized porcine pulmonary extracellular matrix (dECM) with hyaluronic acid. To modulate matrix stiffness, the methacrylate groups are introduced into both dECM and hyaluronic acid, followed by photocrosslinking with photoinitiator. The stiffness of the resulting dECM-based hydrogel covers the stiffness of normal or cancerous tissue with varying dECM content. The proliferation and cancer stem cell marker expression of encapsulated SCLC cells are promoted in a compliant hydrogel matrix, which has a low shear modulus similar to that of the normal tissue. The hepatocyte growth factor (HGF) that induces SCLC cell invasion and chemoresistance markedly increases invasiveness and gene expression levels of CD44 and Sox2 in the hydrogel matrix. In addition, HGF treatment causes higher resistance against anticancer drugs (cisplatin and paclitaxel) in the 3D microenvironment. These findings indicate that malignant SCLC can be recapitulated in a pulmonary dECM-based matrix.