957P - Modelling immune-mediated cytotoxicity for HCC with patient-derived organoid co-culture platform

Background

Patient-derived organoids (PDOs) have been generated for various cancer types in recent years. We obtained over 80 hepatocellular carcinoma (HCC) samples, with a viable PDO establishment rate of ∼45%, surpassing current studies. PDOs offer additional treatment options for HCC patients and our study aims to evaluate the predictive immune checkpoint blockade (ICB) response in HCC through PDO co-culture.

Methods

Surgical samples were collected from HCC patients at Prince of Wales Hospital in Hong Kong. The specimens were digested and plated in Matrigel for 3D organoid culture. We then authenticated the phenotypic and genotypic characteristics of PDOs, and performed downstream drug test assays. PDOs were labelled prior to co-culture assay, while CD8⁺ T cells were isolated from peripheral blood mononuclear cells (PBMCs) using microbeads and cultured for 3 days. T cells purity was confirmed by flow cytometry. The cells were then co-cultured in basal medium with 10% Matrigel, with or without the addition of ICB. T cell-mediated apoptosis was quantified by measuring the intensity of Caspase3/7 probe.

Results

The PDOs established from HCC tissues harbored common HCC markers and were treated with targeted therapeutic and chemotherapeutic agents, yet only modest anti-cancer effects were observed. Next, we examined the cytotoxic activity of CD8⁺ T cells through direct co-culture with PDOs and noted a remarkable T cell-mediated apoptosis of PDOs over chemotherapy-treated control. Apoptotic cell death also showed a dose-dependent response to T cell ratios. The PDO co-culture system was further explored to assess ICB response, with moderate expression of PD-L1 in the HCC PDOs. Durvalumab (anti-PD-L1) exhibited a superior apoptotic event on PDO compared to T cell standalone control.

Conclusions

We demonstrated that PDOs from HCC tissues provide a feasible platform for predicting therapeutic response. Furthermore, we evaluated the cytotoxicity of T cells in PDO co-culture system and observed the effectiveness of ICB. This study lays the foundation for evaluating novel or off-label ICB treatments to determine which would be most effective for individual HCC patients.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.