Optimization of patient-derived colorectal cancer organoid culture platform for personalized drug screening

Abstract

In the conventional oncologic approach, patients with the same type of cancer are treated with similar drugs. However, clinical data often show that treatments may work well for some patients and not for others. This is because each patient has a unique profile, which results in different responses to the reference treatments. The use of patient-derived tumor organoids (PDOs) as predictive biomarkers for response to clinical treatment emerges as a potential personalized platform for drug screening for solid tumors. Therefore, the main objectives of the project involve optimizing the PDO generation techniques and the drug screening platform, for further clinical validation. The first step will be to evaluate the reproducibility and robustness of the protocol to produce colorectal cancer PDOs. Samples of colorectal tumors will be collected from resection and biopsy at the Hospital das Clínicas in Ribeirão Preto (HC-FMRP) and at the Cancer Institute of São Paulo (ICESP). Processing and cultivation protocols, standardized in phase 1, will be used to generate PDOs that will be characterized in terms of number, size, cell viability, and presence of tumor markers. Together with ICESP, the method of freezing fresh biological samples will be improved to ensure cell integrity and viability. For this, different formulations of transport and cryopreservation solution will be tested. To increase the efficiency of PDOs production, the feasibility of applying technologies for agitated cultures in suspension will be evaluated. Once this production is optimized, a bioprinter will be used to plate the PDOs in 96 and 384-well plates in a reproducible and miniaturized manner, automating the platform for drug screening. Finally, validation studies will be started, correlating the functional results obtained in the in vitro platform with data from clinical trials and in the real world. Once the project is successfully completed, we expect: to produce PDOs from colorectal tumor samples from different patients using a reproducible protocol; to get a sufficient number of viable PDOs in a short amount of time; to improve the conservation capacity of samples for transport over long distances, enabling access to other locations in the State of São Paulo; to standardize the use of the bioprinter for faster and more reproducible plating; and to obtain a high prediction rate of PDOs regarding clinical response. Once validated, the drug screening platform with colorectal tumor PDOs will be used by Living Out to offer a personalized treatment selection service, indicating which are more likely to be effective for a particular colorectal cancer patient. The data obtained regarding the functional profile of these drugs can be used in synergy with pharmacogenomic tests to guide the oncologist in choosing the individualized treatment. In the future, it is expected to apply the platform to other types of solid tumors. The service can be applied to: newly diagnosed patients; treatment combination evaluation; situations where there are several drugs with the same effect; patients in relapse, when the cancer reappears after having gone through all the standard lines of treatment; refractory tumors, when the cancer does not respond to treatment; metastatic tumors; rare tumors without well-established treatment protocols. The more assertive the choice of treatment, the faster the patient can improve, reducing their suffering with side effects and increasing their quality of life. As a result, shorter hospital stays result in considerable savings for operators and healthcare systems. (AU)