A human ex vivo coculture model to investigate peritoneal metastasis and innovative treatment options

Abstract

Objectives Peritoneal metastasis (PM) is commonly observed in patients with colorectal cancer (CRC). The outcome of these patients is poor, with an average survival of only six months without therapy, which requires a better understanding of PM biology and new treatment strategies. Methods We established and characterized a human ex vivo peritoneal model to investigate the mechanisms of peritoneal seeding and possible treatment options. For this, CRC cell lines and patient-derived tumor organoids were cultured together with human peritoneum to investigate the invasion of malignant cells and the effects of local chemotherapy. Results Fresh human peritoneum was cultured for up to three weeks in a stainless steel ring system, allowing for survival of all peritoneal structures. Peritoneal cell survival was documented by light microscopy and immunohistochemical staining. Further, immunohistological characterization of the tissue revealed CD3-positive T-lymphocytes and vimentin-positive fibroblasts within the peritoneum. In addition, extracellular matrix components (collagens, matrix metalloproteinases) were localized within the tissue. Coculture with CRC cell lines and patient-derived CRC organoids revealed that cancer cells grew on the peritoneum and migrated into the tissue. Coculture with CRC cells confirmed that hyperthermal treatment at 41 °C for 90 min significantly enhanced the intracellular entry of doxorubicin. Moreover, treatment with mitomycin C under hyperthermic conditions significantly reduced the amount of cancer cells within the peritoneum. Conclusions This human ex vivo peritoneal model provides a stringent and clinically relevant platform for the investigation of PM and for further elucidation of possible treatment options.

Establishing a New Platform to Investigate the Efficacy of Oncolytic Virotherapy in a Human Ex Vivo Peritoneal Carcinomatosis Model

“…In the next step, the virotherapeutic effectiveness of GLV-0b347 and MeV-DsRed was tested for the first time with normal/nonmalignant peritoneum obtained from noncancer patients co-cultured with GFP/luc-labeled HT-29 cancer cells. For this purpose, the peritoneum obtained from the surgery room was inserted immediately between stainless steel rings, as described before [ 6 ] ( Figure 4 A,B). Next, GFP/luc-HT-29 cancer cells were seeded onto the peritoneum and, after subsequent attachment, infected with the oncolytic viruses GLV-0b347 or MeV-DsRed at a fixed virus dosage of 1.5 × 10 6 plaque-forming units (pfu) ( Figure 4 C).…”

“…Hence, the establishment of peritoneal ex vivo models is of particular relevance not only for cancer research, including the study of treatment options for PC in a physiologically adequate tumor microenvironment but also for the development of personalized virotherapy in the future. Recently, a human ex vivo model was established to mimic PC formation and to test possible treatment options for PC [ 6 , 7 ].…”

Pharmacologic Targeting of MMP2/9 Decreases Peritoneal Metastasis Formation of Colorectal Cancer in a Human Ex Vivo Peritoneum Culture Model

“…We also analysed the expression levels of MMPs and other candidate genes relevant to the PC of CRC in HT29 and Colo205 cells in our ex vivo PC model. For this, we used the previously established human ex vivo peritoneal model, which allows for the investigation of PC formation and possible treatment options in a clinically relevant ex vivo system [ 15 ] ( Figure 2 A). In this model, fresh human peritoneal tissue was obtained from the surgery room and directly inserted between two stainless steel rings.…”

“…In this model, fresh human peritoneal tissue was obtained from the surgery room and directly inserted between two stainless steel rings. To mimic PC formation and to analyse the molecular mechanisms’ underlying metastasis formation, the tissue was co-cultured with GFP-transduced CRC cells to induce PC, as described previously [ 15 ] ( Figure 2 B). Cells were co-cultured with cellularised or decellularised peritoneum to determine the roles of cellular and acellular ECM components, respectively, and their effects on gene expression in CRC cells during co-culture.…”

Establishment of the SIS scaffold-based 3D model of human peritoneum for studying the dissemination of ovarian cancer

“…Small intestinal submucosa scaffold (SIS) derived from pigs has already been successfully used to generate 3D models of skin, airway, and intestine, 10 , 11 as well as of the urogenital tract mucosal surfaces. 12 Regarding the peritoneal models, apart from the usage of explants, 13 , 14 there have been several reports, in which either human omentum fibroblasts were mixed with the ECM and covered by a layer of primary human mesothelial cells, 15 or an artificial human peritoneal tissue was generated by cell-accumulation technique. 16 A peritoneal model using a porous matrix as support has not been described so far.…”