Treatment Analysis via Individualised Organoid Responses (TAILOR)

— Background — Colorectal cancer (CRC) kills >0.9 million people per year worldwide and new treatment approaches are desperately needed. The CRC tumour microenvironment (TME) comprises mutated cancer cells, stromal fibroblasts, and various immune cells.

Despite the considerable influence of the TME, anti-cancer drugs are typically tested against cancer cells in isolation. As a result, we do not understand how TME cells regulate personalised therapy responses. Patient-derived organoids (PDOs) are personalised, stem cell-driven, biomimetic models of an individual’s cancer.

PDOs possess high plasticity and can be polarised towards different cell-states.

However, epithelial PDO monocultures do not recapitulate the heterocellular TME which any therapy must navigate to be effective and therefore cannot model the influence of stromal and immune cells on therapy responses.

My laboratory has recently shown that cancer associated fibroblasts (CAFs) are major regulators of patient-specific drug responses using a novel PDO TME co-culture system and custom single-cell signalling technologies.

We discovered CAFs protect PDOs from chemotherapies by altering cancer cell signalling networks and cell-state in a patient-specific manner. Using this platform, we will now be able to ask: 1. Do our observations hold true across a large autologous patient cohort? 2. Do normal fibroblasts, CAFs, and leukocytes regulate patient-specific drug responses? 3.

Can mechanistic insights be leveraged to overcome therapy resistance? — Aims — To answer these questions, I propose a translational research programme entitled: ‘Treatment Analysis via Individualised Organoid Responses’ (TAILOR). TAILOR has the following primary aims: 1.

Understand patient-specific intra- and inter-cellular signalling therapy-response mechanisms at single-cell resolution across a broad CRC cohort. 2. Explore patient-specific CRC therapy-induced canalisation regulated via cell-intrinsic and cell-extrinsic cues. 3.

Use mechanistic understanding to re-sensitise refractory CRC. — Methods — TAILOR will use autologous Patient-Derived Microenvironment (PDM) organoids from UCL Hospital to study individualised treatment responses in CRC.

PDMs comprise systematic combinations of epithelial PDOs with normal fibroblasts, CAFs, tumour infiltrating lymphocytes (TILs), and peripheral blood mononuclear cells (PMBCs).

We will analyse intra-cellular signalling using thiol-reactive organoid barcoding in situ mass cytometry (TOBis) and inter-cellular cell-cell communication with a new SPLiT-Seq method developed by my laboratory. — How the Results of This Research Will Be Used — TAILOR will combine unique autologous cancer models with custom single-cell technologies, to reveal fundamental biological mechanisms underlying patient-specific drug responses.

These results will help us understand TME and therapy induced cell-state transitions to develop rational patient-specific drug re-sensitisation strategies.