Establishment of Precision-Cut Tumor Slices for Pre-Clinical Evaluation of Existing and Novel Therapeutics

Abstract

Most pre-clinical models fail to reliably predict the effects of immunotherapeutic drugs intended for treatment of cancer. A major limitation is their inability to reliably model the tumor microenvironment (TME), a complex and essential component of tumor resistance to treatment. Patient-derived tumor models, like precision-cut tumor slices (PCTS), preserve the tumor architecture and capture the cell populations of the TME, including the critical elements of the immune system, making them an ideal platform for testing therapeutic modalities. In this study, we develop an ex vivo bladder tumor model using bladder PCTS and initiate establishment of the model in ovarian cancer.

Fresh tumor tissue was cut into slices with 300 µm thickness using a vibratome. PCTS were cultivated for up to three days including overnight recovery to ensure stable tissue viability. Initial establishment of ovarian PCTS evaluated preservation of tissue architecture and cell subsets through H&E staining and high-plex flow cytometry. The PCTS from both tumor types were treated with immune stimulating agents (CD3/CD28), PCTS from bladder were further treated with chemotherapeutics (gemcitabine and cisplatin), or immunotherapeutic (anti-PD-1 antibody, Nivolumab). Response signatures were assessed after 24 h using H&E- and immunofluorescence staining, high-plex flow cytometry and multiplex immunoassays (Luminex).

PCTS maintained tissue architecture and viable cells, including immune cell subsets, throughout the culture period. Immune cells remained functional, represented by T cells showing elevated levels of activation markers upon exposure to immunostimulants. As in the clinical setting, anti-PD-1 responses were patient-dependent where PCTS from 2 out of 9 patients responded with secretion of inflammatory cytokines and chemokines like Granzyme B and IP10. The findings suggest the PCTS model and the established workflow to be highly robust and applicable also in other types of cancers. Overall, PCTS present a promising pre-clinical model of high translational value.

Popular Abstract

Slicing into cancer: 3D tumor slice model brings us closer to personalized cancer treatment

Cancer research has made significant progress over the last decade. Despite this, many types of cancer are still difficult to treat, and a large portion of patients don’t respond well to the current treatments, pointing to a need for new innovative approaches.

In recent years, a new type of cancer treatment called immunotherapy has revolutionized the way we treat cancer. Instead of broadly attacking cancer like traditional chemotherapy, immunotherapy works by helping the body’s own immune system recognize and directly kill cancer cells. For some patients, this has led to long-lasting responses and overall longer survival times. Unfortunately, not all patients benefit from immunotherapy, as tumors from two individuals can be incredibly diverse, making standardized treatments difficult. Additionally, tumors can employ clever tricks to hide from or suppress the immune system, making these treatments less effective.

To develop better, more personalized cancer therapies, meaning the right treatment for the right patient at the right time, we need advanced lab models that can accurately represent how tumors behave in the human body. Traditional cancer models often fail to capture the full picture, many solely focus on the cancer cells and as such do not consider the importance of immune cells. Moreover, in the case of animal models they don’t always translate into human physiology. This means that crucial information regarding treatment response is lost, leading to the failure of many drug candidates and them never reaching the patients. This is where Precision Cut Tumor Slices (PCTS) come in. PCTS are thin slices generated from tumor tissue which has been removed from patients by surgery. What makes them unique is that they contain the original features of the tumor, including its various cell types and supporting tissue, just like it was in the human body. Because of this, PCTS offers a powerful way to study how a specific patient’s tumor responds to different treatments.

In this project, tumor tissue from the bladder and ovaries were used for developing the PCTS model. First, we confirmed the maintained architecture and survival of the tissue in the slices. It was possible to characterize the PCTS, gaining valuable insight into the cellular composition and confirming the survival of both tumor and immune cells. Next, we challenged the model, testing the responsiveness of the immune cells in the slices, an essential aspect necessary for the model to be used for pre-clinical testing. The slices generated a measurable increase in signaling molecules and proteins on the immune cells, meaning that the cells have responded to the challenge, being not just alive but able to be activated. We further tested therapeutics that are currently used in the clinic. Overall, by comparing results between patients we showcase just how different these tumors can be and how important these types of models are. Using PCTS, researchers can test how a tumor reacts outside the body, which could help guide treatment decisions and improve the development of more effective, personalized cancer therapies.

Master’s Degree Project in Molecular Biology: Immunology & Infection biology, 60 credits, 2025. Department of Biology, Lund University.

Advisor: Kristina Lundberg & Sarah Richtmann.
Department of Immunotechnology, LTH, Lund University.

• author: Radak, Maja
• supervisor: Kristina Lundberg; Sarah Richtmann
• organization: Degree Projects in Molecular Biology
• course: MOBN03 20242
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Biology and Life Sciences
• language: English
• id: 9214709
• date added to LUP: 2025-10-31 16:18:31
• date last changed: 2025-10-31 16:18:31