# 3D pentaculture model unveils malignant cell-driven macrophage polarization in high-grade serous ovarian cancer

## TL;DR

A 3D lab model of ovarian cancer shows how cancer cells influence immune cells called macrophages in the tumor environment.

## Contribution

A novel 3D pentaculture model reveals malignant cell-driven macrophage polarization in HGSOC.

## Key findings

- Macrophage clusters in the model match those in human HGSOC metastases.
- Malignant cell heterogeneity influences macrophage activity and tumor environment.
- Anti-CD47 and anti-CD24 antibodies affect macrophage behavior and cancer cell viability.

## Abstract

High-grade serous ovarian cancer (HGSOC) is characterized by a complex, immunosuppressive tumor microenvironment (TME) that contributes to poor clinical outcomes and resistance to therapy. To replicate the human TME in vitro, we develop a 3D pentaculture model incorporating five human cell types: malignant HGSOC cells and primary fibroblasts, mesothelial cells, adipocytes, monocytes. Monocytes differentiate into macrophages without exogenous cytokines in the pentacultures. Bulk RNA sequencing and deconvolution with single-cell RNA data from patient biopsies reveal that macrophage clusters within the pentacultures replicate those found in human HGSOC metastases, and proportions of individual clusters vary according to the malignant cell line. The pentacultures enable detailed analysis of malignant cell–macrophage interactions and highlight the influence of malignant cell genomic, transcriptomic and proteomic heterogeneity on the TME. Furthermore, targeting of “do-not-eat-me” signals with anti-CD47 and anti-CD24 monoclonal antibodies demonstrate differential effects on macrophage activity and cancer cell viability, again depending on the individual malignant cell line. Real-time microscopic monitoring of the pentacultures confirms dynamic modulation of macrophage behavior. We conclude that this pentaculture model offers a platform to study malignant cell control of TME elements and in particular their interactions with myeloid cells.

High-grade serous ovarian cancer (HGSOC) is characterised by a complex tumour microenvironment contributing to poor clinical outcomes and resistance to therapy. Here, the authors develop a 3D pentaculture in vitro model of HGSOC incorporating five human cell types, revealing how malignant cells drive macrophage polarisation and influence the tumour microenvironment.