Advanced 3D model for assessing efficacy of ovarian cancer therapy

Christiane Helgestad Gjerde defended her dissertation Development of Advanced 3D Ovarian Carcinoma Models at the University of Bergen June 24, 2024. Main supervisor has been Professor Line Bjørge, with co-supervisors Professor Emmet McCormack and Researcher Katrin Kleinmanns. The project was financed by the University of Bergen, Helse Vest and the Kolbjørn Brambani grant.

Targeting an aggressive cancer type

Epithelial ovarian cancer (EOC) is the leading cause of death from gynecological cancers. The disease is usually diagnosed at advanced stages, leading to a poor prognosis. The most aggressive subtype of EOC, high-grade serous ovarian carcinoma (HGSOC), primarily metastasizes within the peritoneal cavity. Peritoneal metastases exhibit unique genomic features and tumor microenvironments (TMEs) distinct from the primary tumor and other metastatic sites. Both the cells and the noncellular compartment of the TME influence therapy response. Advanced preclinical models allow us to study tumor biology and evaluate the efficacy of new therapies. Three-dimensional (3D) in vitro tumor models can recapitulate various aspects of the TME. However, existing models using artificial hydrogels fail to replicate the complex extracellular matrix (ECM) architecture of native tissues. Decellularized ECM (dECM) tissue scaffolds offer a promising alternative that replicates tissue architecture and can be used for 3D model establishment. No peritoneal dECM scaffold exists. 

A more realistic preclinical in vitro model

The main goal of this thesis was to establish a preclinical in vitro model of HGSOC peritoneal metastases. The group aimed to create a scaffold that would mimic the ECM of the native peritoneum and use this to establish a 3D in vitro model of HGSOC that could be used to evaluate the efficacy of traditional chemotherapy and a novel cellbased immunotherapy.

Porcine and human peritoneal tissue were chemically and enzymatically decellularized to generate a dECM scaffold. The scaffold’s structure and composition were characterized using histology, multiphoton microscopy, rheology, a permeability assay, and proteomic analysis and compared to the established small intestinal submucosa (SIS) scaffold. A custom-designed culture plate insert was developed to enable the use of a novel dECM scaffold for cell culture, termed peritoneal matrix (PerMa). EOC and fibroblast cell lines were cultured on the dECM scaffold and subjected to treatment with carboplatin chemotherapy (Paper I) and chimeric antigen receptor (CAR) T cell therapy (Paper I & II). Confocal microscopy was used to assess cell growth and viability.

The group developed a novel dECM scaffold, PerMa, derived from porcine and human peritoneum (Paper I). The PerMa maintained the structural integrity of major ECM components, with minor batch-to-batch variation. The porcine PerMa (pPerMa) closely reflected the ECM architecture of the human PerMa derived from autopsies (hPerMa) and ovarian cancer patients (ocPerMa). Comparisons between the PerMa and the SIS revealed differences in the protein diversity and the composition of matrisome proteins. The porcine PerMa supported the 3D growth of HGSOC and fibroblast cell lines in a cell culture system using a custom-designed culture plate insert. The cytotoxicity of chemotherapy and cell-based immunotherapies was assessed by quantification of the fluorescence signal of the HGSOC cell lines (Paper I). A novel CAR T cell therapy targeting Mucin 16 was shown to be highly effective in killing tumor cells in both the 3D model and xenograft mouse models (Paper II).

In-depth characterization of the decellularized pPerMa confirms the similarity to the human PerMa, the integrity of the ECM architecture of native peritoneum and the growth of HGSOC and fibroblast cell lines (Paper I).

The PerMa 3D model presents a valuable model to assess the efficacy of traditional chemotherapy (Paper I) and novel cell-based immunotherapies (Paper I & II).