Constructing an in vitro choriocarcinoma model by three-dimensional bioprinting

Choriocarcinoma is a rare and highly aggressive trophoblastic tumor. Although in-depth research has been conducted on the treatment options for choriocarcinoma, especially chemotherapy regimens, there are still 10% to 20% of choriocarcinoma patients who develop resistance or experience tumor recurrence. The research on the pathogenesis of choriocarcinoma and its treatment remains a major challenge and an unresolved clinical issue. Accurately replicating the key characteristics of choriocarcinoma in preclinical tumor models is crucial for research into tumor mechanisms and treatment. Up to now, the lack of a universal in vitro model required for studying tumor-related diseases is a key problem faced by researchers. It is notable that three-dimensional bioprinting (3DP) technology has seen expanding utilization across multiple domains of biomedical research. To this end, we aimed to employ 3DP technology to construct an in vitro choriocarcinoma model and to comprehensively compare it with conventional two-dimensional (2D) culture systems in multiple aspects.

A 3DP approach was employed to generate an in vitro choriocarcinoma model, and the cells in this model were comprehensively compared with those in traditional 2D cultured cells. A fluorescence live/dead kit was used to assess cell viability. Proliferation of JEG-3 cells was assessed by the Cell Counting Kit-8 (CCK-8) assay. We also analyzed the gene expression of 2D and 3D bioprinted cells. Finally, we used antitumor drugs to conduct drug response tests on the cells in the 2D and 3DP groups.

The cells in the 3DP system exhibited stronger vitality, metabolic activity, and key tumor biological characteristics, compared to the cells cultured in a single layer in the 2D cultures. Throughout the entire observation window, JEG-3 cells in the 3D bioprinted model proliferated more robustly, suggesting that the 3D bioprinted environment supports sustained cell growth and is suitable for long-term experiments. Cells in the 3D bioprinted model exhibited significantly higher levels of genes associated with proliferation, metastasis, drug resistanace, immune suppression, and epithelial-to-mesenchymal transition (EMT), compared to those cultured in 2D. We also found that the 3D bioprinted model released markedly greater amounts of human chorionic gonadotropin (hCG) than the 2D culture. The results of drug screening assays indicated that the half-maximal inhibitory concentration (IC₅₀) values for three tested chemotherapeutic agents were substantially elevated in the 3D bioprinted model relative to the 2D model.

This study demonstrates the feasibility of engineering a 3D bioprinted tumor model using a composite hydrogel system to mimic the in vivo tumor microenvironment more effectively. The 3D bioprinted microtissue model provides a realistic platform for studying cancer cell behavior and holds significant promise for preclinical applications, particularly in advancing our understanding of choriocarcinoma. This approach is adaptable to other tumor types and could significantly contribute to the development of personalized therapeutic strategies.