Influence of Matrices on 3D-Cultured Prostate Cancer Cells' Drug Response and Expression of Drug-Action Associated Proteins

This study investigated the effects of matrix on the behaviors of 3D-cultured cells of two prostate cancer cell lines, LNCaP and DU145. Two biologically-derived matrices, Matrigel and Cultrex BME, and one synthetic matrix, the Alvetex scaffold, were used to culture the cells. The cell proliferation rate, cellular response to anti-cancer drugs, and expression levels of proteins associated with drug sensitivity/resistance were examined and compared amongst the 3D-cultured cells on the three matrices and 2D-cultured cells. The cellular responses upon treatment with two common anti-cancer drugs, Docetaxel and Rapamycin, were examined. The expressions of epidermal growth factor receptor (EGFR) and β-III tubulin in DU145 cells and p53 in LNCaP cells were examined. The results showed that the proliferation rates of cells cultured on the three matrices varied, especially between the synthetic matrix and the biologically-derived matrices. The drug responses and the expressions of drug sensitivity-associated proteins differed between cells on various matrices as well. Among the 3D cultures on the three matrices, increased expression of β-III tubulin in DU145 cells was correlated with increased resistance to Docetaxel, and decreased expression of EGFR in DU145 cells was correlated with increased sensitivity to Rapamycin. Increased expression of a p53 dimer in 3D-cultured LNCaP cells was correlated with increased resistance to Docetaxel. Collectively, the results showed that the matrix of 3D cell culture models strongly influences cellular behaviors, which highlights the imperative need to achieve standardization of 3D cell culture technology in order to be used in drug screening and cell biology studies.