Here, we present a protocol to construct a three-dimensional in vitro model of the lining of the peritoneal cavity, composed of primary human mesothelial cells and fibroblasts layered with extracellular matrix, as a tool to investigate ovarian cancer cell adhesion, invasion, and proliferation.
The pattern of ovarian cancer metastasis is markedly different from that of most other epithelial tumors, because it rarely spreads hematogenously. Instead, ovarian cancer cells exfoliated from the primary tumor are carried by peritoneal fluid to metastatic sites within the peritoneal cavity. These sites, most notably the abdominal peritoneum and omentum, are organs covered by a mesothelium-lined surface. To investigate the processes of ovarian cancer dissemination, we assembled a complex three-dimensional culture system that reconstructs the lining of the peritoneal cavity in vitro. Primary human fibroblasts and mesothelial cells were isolated from human omentum. The fibroblasts were then mixed with extracellular matrix and covered with a layer of the primary human mesothelial cells to mimic the peritoneal and omental surfaces encountered by metastasizing ovarian cancer cells. The resulting organotypic model is, as shown, used to examine the early steps of ovarian cancer dissemination, including cancer cell adhesion, invasion, and proliferation. This model has been used in a number of studies to investigate the role of the microenvironment (cellular and acellular) in early ovarian cancer dissemination. It has also been successfully adapted to high throughput screening and used to identify and test inhibitors of ovarian cancer metastasis.
Ovarian cancer is the deadliest gynecologic malignancy1. The majority of patients are diagnosed after the cancer has disseminated throughout the peritoneal cavity. Once the cancer has spread throughout the peritoneal cavity, cytoreductive surgery and chemotherapy are often not sufficient treatment to prevent cancer recurrence and chemoresistance, resulting in a less than 30% 5-year survival rate. Ovarian cancer metastasis is predominantly limited to the peritoneal cavity, and several other cancer types, including gastric, pancreatic, and colon cancers, metastasize to the same anatomic sites in the peritoneal cavity. In general, ovarian cancer cells detach from the in situ carcinoma in the fallopian tube or the primary ovarian tumor, travel in peritoneal fluid as single cells or spheroids, and attach to mesothelium-lined surfaces of the omentum, bowel, and abdominal wall2.
The tumor microenvironment plays an important role in disease progression and chemoresistance in many cancers3-6. The peritoneal cavity is a unique microenvironment, with a mesothelial cell monolayer covering the majority of surfaces (Figure 1A)7. The mesothelial lining acts as a barrier that creates a low-friction surface, which tends to be protective against cancer cell adhesion8. Immediately underneath this mesothelial-lined surface is a layer made predominantly of fibroblasts and extracellular matrix (ECM), which promote cancer cell adhesion and invasion8. Ovarian cancer cells secrete factors that induce changes in the mesothelial cell lining that enhance ovarian cancer cell adhesion, invasion, and metastasis9,10. Ovarian cancer cells adhere to the mesothelial surface via integrin and CD44-mediated mechanisms (Figure 1B)11-16.
Historically, several 3D models have been developed to investigate ovarian cancer interactions with the microenvironment. Some of the first models studied ovarian cancer-ECM interface17-21, ovarian cancer-mesothelial cell communication13,14,21-24, or both25 (reviewed by us 26). Niedbala et al. discovered that ovarian cancer cells display a quicker and firmer adhesion to ECM than to mesothelial cells or to plastic alone25. However, these models did not histologically resemble the peritoneal microenvironment. Therefore, we established a 3D organotypic model to more thoroughly replicate the ovarian cancer microenvironment. In order to better understand the role of the microenvironment and the interaction between cancer and peritoneal cells in the peritoneal dissemination of ovarian cancer, we have developed a 3D organotypic in vitro culture model of the peritoneal cavity lining (schematic in Figure 1C). The proposed model is composed of primary human fibroblasts and ECM, covered with a layer of primary human mesothelial cells-each cell type is isolated from human omentum. Histologically, this model resembles the normal peritoneal or omental lining, and provides a surface on which we can study the tumor microenvironment, the interaction between cancer cells and normal tissue, and the processes of cancer cell adhesion, invasion, and proliferation8.
Een organotypische model van peritoneale micro opgericht om de individuele en collectieve functie (s) van zowel de cellulaire en aangeboren bestanddelen van de micro-omgeving bij eierstokkanker verspreiding van kanker te beoordelen. De specifieke protocollen voor plateren en het aanpassen van de 3D organotypische kweek eierstokkanker celhechting, proliferatie, invasie en onderzoeken zijn aanwezig. Omental primaire humane mesotheelcellen en fibroblasten werden geïsoleerd uit patiënten die in een vroeg doorgang naar nor…
The authors have nothing to disclose.
We thank all residents and attending physicians, notably Dr. A.F. Haney (the University of Chicago, Department of Obstetrics and Gynecology) for collecting omental biopsies. Also, we thank Stacey Tobin and Gail Isenberg for carefully editing this manuscript. This work was supported by Bears Care, the charitable beneficiary of the Chicago Bears Football Club, the National Institute of Neurological Disorders and Stroke (NINDS) R21 NS075702, and the National Cancer Institute grant R01 CA111882 to E.L.
1. Isolation and culture of primary cells | |||
PBS | Fisher Scientific | SH3001304 | |
Single-edged razor blades | Fisher Scientific | 12-640 | |
15 cm culture dishes | BD Biosciences | 353025 | |
Glass flask | ? | ? | |
Fetal Bovine Serum (FBS) | Life Technologies | 16000044_3616914956 | |
DMEM with L-Glutamine | Corning | 10-013-CV | |
MEM Vitamins | Corning | 25-020-Cl | |
MEM Nonessential amino acids | Corning | 25-025-CI | |
Penicillin-Streptomycin | Corning | 30-002-CI | |
Shaker | Thermo-Fisher | MaxQ 4450 | |
Centrifuge | Eppendorf | 5702 | |
Incubator | Thermo-Fisher | Forma Series II Water Jacketed CO2 Incubator Model 3100 | |
Trypsin EDTA, 1x (0.25%) | Corning | 25-053-CI | |
Hyaluronidase | Worthington Biochemical | LS002592 | |
T-75 Flasks | BD Biosciences | 353136 | |
T-175 Flasks | BD Biosciences | 353112 | |
Pipet tips | Rainin | P2, P10, P20, P200 and P1000 | |
Pipet tips | Corning | Filtered tips P2, P10, P20, P200 and P1000 | |
Name of Reagent/ Equipment | Company | Catalog Number | Comments/Description |
2. Plating 3D culture | |||
Cell Counter | Invitrogen | Countess | |
Countess Cell Counting Chamber Slides | Invitrogen | C10313 | |
Trypan Blue Stain (0.4%) | Gibco | 15250-061 | |
Collagen Type I (Rat Tail) | BD Biosciences | 354236 | |
96 well plate, clear bottom, black | BD Biosciences | 353219 | |
Name of Reagent/ Equipment | Company | Catalog Number | Comments/Description |
3. Adhesion assay | |||
Multichannel pipet | Eppendorf | Xplorer 300 | |
Paraformaldehyde solution 4% in PBS | Santa Cruz Biotechnology | sc-281692 | |
Plate reader | Molecular Devices | Minimax | |
Name of Reagent/ Equipment | Company | Catalog Number | Comments/Description |
5. Invasion assay | |||
Cell Culture Inserts (8um, 24-well) | BD Biosciences | 353097 | |
Cotton swabs | Q-tips | cotton swabs | |
Microscope | Zeiss | Axiovert 200m | |
Cell Profiler | public domain | ||
24 well plate | BD Biosciences | 353047 | |
Name of Reagent/ Equipment | Company | Catalog Number | Comments/Description |
6. Antibodies | |||
Anti-Integrin αVβ3 Antibody, clone LM609 | EMD Millipore | MAB1976 | |
Beta 1 | Oncosynergy | OS2966 | |
Alpha 5 [CD49e] | ID Pharmingen | 555615 | |
Beta 4 [CD104] | EMD Millipore | MAB 2058 |