human omentum specimen processing and co-culture with ovarian cancer cells

Establishing a 3D Ex Vivo Model for Ovarian Cancer-Omentum Interaction

Ovarian cancer is the deadliest gynecologic malignancy worldwide1. The lifetime risk of developing this cancer is approximately 1 in 70, with the median age of diagnosis at 63 years old2. Primary ovarian malignancies are classified histologically as either epithelial or non-epithelial. Epithelial ovarian cancers (EOC) represent over 90% of tumors, and the most common subtype is high-grade serous carcinoma (HGSC), which accounts for approximately 70%-80% of EOCs. Currently, there are no effective screening methods to detect disease early. So most patients are diagnosed at an advanced stage (i.e., F&#233;d&#233;ration Internationale de Gyn&#233;cologie et d&#39;Obst&#233;trique [FIGO] stage III or IV) after the cancer has spread throughout the peritoneal cavity2.
Standard frontline treatment is cytoreductive surgery to remove all visible macroscopic disease, followed by adjuvant platinum-based chemotherapy to destroy any residual microscopic disease. While there have been many advances in ovarian cancer treatment over the last two decades, approximately 70% of patients with advanced disease will relapse within 3 years of treatment3. Given the overall poor prognosis of these patients, ongoing and future translational research efforts in EOC aim to identify biomarkers for early detection, prevent metastasis, improve current therapies to evade resistance and develop new personalized cancer treatments.
Generalized metastasis within the peritoneal cavity and its associated chemoresistance are two of the major limitations for the improvement of the treatment of patients with ovarian cancer4,5. The omentum, a fatty apron-like structure that hangs down from the stomach over the intestines, is a main site of ovarian cancer metastasis6,7. In addition to its function as a physical barrier, the omentum has been shown to have regenerative and angiogenic capacities and possess immune activities, which together promote vascularization, accelerate wound healing, and limit infection8. It contains a high concentration of stem cells that can differentiate into various cell types and can help repair damaged tissues. The omentum can become inflamed in response to injury or infection, which triggers the migration of immune cells to the site of injury9. These immune cells release growth factors and other molecules that help to promote the repair and regeneration of damaged tissue. Immune cells, such as macrophages, lymphocytes, and plasma cells, localized in the omentum are structures known as &#34;milky spots&#34;, which are responsible for detecting and attacking pathogens and regulating peritoneal immunity. The omentum has also been shown to play a role in inducing immune tolerance10, which is the ability of the immune system to tolerate self-antigens and not attack healthy tissues. However, the same immune-related activities are also involved in pathological responses, such as the growth of omental tumors, metastasis, and escape of immune surveillance9,11. Previous studies from our lab and others have demonstrated a unique and active role of the adipose microenvironment in the inhibition of anti-tumoral immune responses and in the acquisition of chemoresistance12,13,14. Unfortunately, we have limited information on the cellular and molecular mechanisms by which the omentum provides a pro-tumoral microenvironment.
To better understand the interactions between cancer cells and the omentum, a 3D culture system consisting of human ovarian cancer cells and patient-derived omentum explants was developed. The protocol described here represents a novel ex vivo model of peritoneal carcinomatosis. This model mimics the natural progression of ovarian cancer tumorigenesis in this adipose-rich tissue. The proposed model is easy to generate, inexpensive, and potentially applicable to translational investigations in ovarian cancer research.

Author Spotlight: Advanced Ex Vivo Model for Investigating Cancer-Adipose Microenvironment Interaction 

An Ex Vivo Model of Ovarian Cancer Peritoneal Metastasis Using Human Omentum

Current studies use co-culture systems comprised of isolated adipocytes and ovarian cancer cells. These adipocytes are differentiated in vitro from pre adipocytes. These cells are then separated through a transwell insert and therefore lack direct cell to cell contact.This ex vivo culture method offers a model to study the direct interaction of cancer cells with the adipose microenvironment. Our model preserves the structure of the human momentum and therefore maintains the various cell types that are typically in this organ. In addition to adipocytes, these cells include supporting fibroblasts as well as immune cells.This model also maintains these cells in their inherent matrix. This model provides an excellent platform for the development and evaluation of novel therapeutic approaches to target metastatic cancer cells in this niche.

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Human Omentum Specimen Processing and Co-Culture with Ovarian Cancer Cells  

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JoVE Journal

Cancer Research

770 Views.  Karmanos Cancer Institute. Human Omentum Specimen Processing and Co-Culture with Ovarian Cancer Cells