Generation and Integrated Analysis of Advanced Patient-Derived Orthoxenograft Models (PDOX) for the Rational Assessment of Targeted Therapies in Endometrial Cancer

The role of the pathologist in the design and conducting of biomarker-driven clinical trials in cancer: position paper of the European Society of Pathology

Clinical trials in oncology are important tools to identify and establish new effective drugs for cancer treatment. Since the development of the concept of precision oncology, a huge number of multi-centric biomarker-driven clinical trials have been performed and promoted by either academic institutions or pharmaceutical companies. In this scenario, the role of pathologists is essential in multiple aspects, with new challenges that should be addressed. In this position paper of the European Society of Pathology, the role of pathologists as contributors to the design of the clinical trial, as local collaborators, or as members of central review laboratories is discussed. Moreover, the paper emphasizes the important role of pathologists in guiding methods and criteria of tissue biomarker testing in the biomarker-driven clinical trials. The paper also addresses issues regarding quality control, training, and the possible role of digital pathology.

Prognostic implication of CD47 and CTLA-4 expressions in endometrial carcinoma

BACKGROUND

CD47 is an immune-regulatory protein that belongs to the immunoglobulin family. It inhibits the phagocytic ability of immune cells. So, it is related to an unfavorable outcome in leukemia and various solid tumors. One of the immune checkpoint molecules is cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) which interferes with anticancer immunity and has an important role in anti-cancer surveillance. This study aimed to investigate CD47 and CTLA-4 mRNA and protein expressions in relation to P53 mutation and different clinicopathological parameters in endometrial carcinoma (EC). We also investigated the relation between CD47 and CTLA-4 expressions in EC.

SUBJECT & METHOD

This study included sixty-eight patients with EC. Tissue samples of the tumor with adequate safety margin were obtained. Part of the tissues was preserved in formalin for histopathological and immunohistochemical examination while the other part was kept frozen at -80 °C for molecular profile.

RESULTS

CD47 and CTLA-4 gene expressions were upregulated in the tissues of EC in comparison with the adjacent control tissues. Significantly higher CD47 and CTLA-4 gene expressions were detected in the serous type, higher stage, muscle invasion ≥50 %, higher grade, LN metastasis, and distant metastasis. CD47 gene expression was a good marker of P53 mutation at a cut-off of 1.65. It showed a high sensitivity of 84 %, a high specificity of 75.3 %, an average PPV of 65.6 %, a high NPV of 88.9 %, and an accuracy of 77.9 % (P < 0.001). Similarly, CTLA-4 gene expression was a good marker of P53 mutation at a cut-off of 3.75. It showed a sensitivity of 88 %, a specificity of 74.3 %, a PPV of 66.7 %, an NPV of 91.4 %, and an accuracy of 79.4 % (P < 0.001).

CONCLUSION

CD47 and CTLA-4 expressions can be considered possible diagnostic and prognostic markers in EC. They were good markers of P53 mutation, and higher tumor grades and stages.

Progress in building clinically relevant patient-derived tumor xenograft models for cancer research

Patient-derived tumor xenograft (PDX) models, a method involving the surgical extraction of tumor tissues from cancer patients and subsequent transplantation into immunodeficient mice, have emerged as a pivotal approach in translational research, particularly in advancing precision medicine. As the first stage of PDX development, the patient-derived orthotopic xenograft (PDOX) models implant tumor tissue in mice in the corresponding anatomical locations of the patient. The PDOX models have several advantages, including high fidelity to the original tumor, heightened drug sensitivity, and an elevated rate of successful transplantation. However, the PDOX models present significant challenges, requiring advanced surgical techniques and resource-intensive imaging technologies, which limit its application. And then, the humanized mouse models, as well as the zebrafish models, were developed. Humanized mouse models contain a human immune environment resembling the tumor and immune system interplay. The humanized mouse models are a hot topic in PDX model research. Regarding zebrafish patient-derived tumor xenografts (zPDX) and patient-derived organoids (PDO) as promising models for studying cancer and drug discovery, zPDX models are used to transplant tumors into zebrafish as novel personalized medical animal models with the advantage of reducing patient waiting time. PDO models provide a cost-effective approach for drug testing that replicates the in vivo environment and preserves important tumor-related information for patients. The present review highlights the functional characteristics of each new phase of PDX and provides insights into the challenges and prospective developments in this rapidly evolving field.

A New Type of Endometrial Cancer Models in Mice Revealing the Functional Roles of Genetic Drivers and Exploring their Susceptibilities

Endometrial cancer (EC) is the most common female reproductive tract cancer and its incidence has been continuously increasing in recent years. The underlying mechanisms of EC tumorigenesis remain unclear, and efficient target therapies are lacking, for both of which feasible endometrial cancer animal models are essential but currently limited. Here, an organoid and genome editing-based strategy to generate primary, orthotopic, and driver-defined ECs in mice is reported. These models faithfully recapitulate the molecular and pathohistological characteristics of human diseases. The authors names these models and similar models for other cancers as organoid-initiated precision cancer models (OPCMs). Importantly, this approach can conveniently introduce any driver mutation or a combination of driver mutations. Using these models,it is shown that the mutations in Pik3ca and Pik3r1 cooperate with Pten loss to promote endometrial adenocarcinoma in mice. In contrast, the Kras G12D mutati led to endometrial squamous cell carcinoma. Then, tumor organoids are derived from these mouse EC models and performed high-throughput drug screening and validation. The results reveal distinct vulnerabilities of ECs with different mutations. Taken together, this study develops a multiplexing approach to model EC in mice and demonstrates its value for understanding the pathology of and exploring the potential treatments for this malignancy.

Highly Mimetic Ex Vivo Lung-Cancer Spheroid-Based Physiological Model for Clinical Precision Therapeutics

Lung cancer remains a major health problem despite the considerable research into prevention and treatment methods. Through a deeper understanding of tumors, patient-specific ex vivo spheroid models with high specificity can be used to accurately investigate the cause, metastasis, and treatment strategies for lung cancer. Biofabricate lung tumors are presented, consisting of patient-derived tumor spheroids, endothelial cells, and lung decellularized extracellular matrix, which maintain a radial oxygen gradient, as well as biophysicochemical behaviors of the native tumors for precision medicine. It is also demonstrated that the developed lung-cancer spheroid model reproduces patient responses to chemotherapeutics and targeted therapy in a co-clinical trial, with 85% accuracy, 86.7% sensitivity, and 80% specificity. RNA sequencing analysis validates that the gene expression in the spheroids replicates that in the patient's primary tumor. This model can be used as an ex vivo predictive model for personalized cancer therapy and to improve the quality of clinical care.