[Establishment of a novel co-cultured liver cancer model based on tumor microenvironment]

Objective: To construct a new co-cultured liver cancer research model composed of activated hepatic stellate cells (aHSC) and liver cancer cells, explore the efficacy difference between it and traditional model, so as to establish a liver cancer research model in vitro and in vivo that can reflect the real clinical efficacy. Methods: A new co-culture model of liver cancer consisting of aHSC and liver cancer cells was constructed. The differences in efficacy between the new co-culture model and the traditional single cell model were compared by cytotoxicity test, cell migration test, drug retention test and in vivo tumor inhibition test. Western blot was used to detect the drug-resistant protein P-gp and epithelial-mesenchymal transition-related proteins. Masson staining was used to observe the deposition of collagen fibers in tumor tissues of tumor-bearing mice. CD31 immunohistochemical staining was used to observe the microvessel density in tumor tissues of tumor-bearing mice. Results: The cytotoxicity of single cell model and co-culture model was dose-dependent. With the increase of curcumin (CUR) concentration, the cell viability decreased, but the cell viability of single cell model decreased faster than that of co-culture model. When the concentration of CUR was 10 μg/ml, the cell viability of the co-culture model was 62.3% and the migration rate was (28.05±3.68)%, which were higher than those of the single cell model [38.5% and (14.91±5.92)%, both P<0.05]. Western blot analysis showed that the expressions of P-gp and vimentin were up-regulated in the co-culture model, which were 1.55 and 2.04 fold changes of the single cell model, respectively. The expression of E-cadherin was down-regulated, and the expression level of E-cadherin in the single cell model was 1.17 fold changes of the co-culture model. Drug retention experiment showed that the co-culture model could promote drug efflux and reduce drug retention. In vivo tumor inhibition experiment showed that the m-HSC+ H22 co-transplantation model had faster tumor growth and larger tumor volume than those of the H22 single cell transplantation model. After CUR treatment, the tumor growths of m-HSC+ H22 co-transplantation model and H22 single cell transplantation model were inhibited. Masson staining showed that the deposition of collagen fibers in tumor tissues of m-HSC+ H22 co-transplantation model mice was more than that of H22 single cell transplantation model. CD31 immunohistochemical staining showed that the microvessel density in tumor tissue of m-HSC+ H22 co-transplantation model was higher than that of H22 single cell transplantation model. Conclusions: The aHSC+ liver cancer cell co-culture model has strong proliferation and metastasis ability and is easy to be resistant to drugs. It is a new type of liver cancer treatment research model superior to the traditional single cell model.