Establishment of a new valid animal model for the evaluation of hyperthermic intraperitoneal chemotherapy (HIPEC) in pediatric rhabdomyosarcoma

Background: Cytoreductive surgery in combination with hyperthermic intraperitoneal chemotherapy has been established as a novel treatment approach for peritoneal sarcomatosis. Despite promising clinical reports, there is still a lack of knowledge regarding optimal drug usage and local effects. Therefore, we intended to establish a murine animal model for further evaluation. Procedure: Alveolar rhabdomyosarcoma cells were xenotransplanted into NOD/LtSz-scid IL2Rγnullmice (n=100). The mice received a continuous intraperitoneal lavage with isotonic saline solution as control- or with cisplatin (30 or 60 mg/m2) as treatment group for 60 minutes at 37 or 42 °C (6 subgroups, each n=16). Tumor spread was documented by an adapted peritoneal cancer index and MRI (n=4). Tumor and tissue samples, harvested at the end of the perfusion, were evaluated regarding morphology, proliferation and apoptosis (H&E-, Ki-67-, Cleaved Caspase 3-staining, TUNEL-assay). Results: Extensive peritoneal sarcomatosis in over 91% of the cases was observed. HIPEC was feasible without acute side effects. Ki-67 staining revealed concentration- or temperature-dependent effects of cisplatin-based HIPEC on the tumors. While Cleaved Caspase-3 showed only sporadic apoptotic effects. TUNEL-assay detected concentration- or temperature-dependent apoptotic effects at the outer tumor surface. MRI scans confirmed the observed tumor dissemination. Conclusion: This is the first animal model for evaluation of HIPEC in pediatric RMS in mice. Cisplatin-based HIPEC had early effects on the proliferation whereas circumscribed apoptotic effects could be detected at the tumor surface. This model allows further insights on the possible efficiency of HIPEC in RMS. Further studies using other drug combinations and treatment will follow.

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Increasing the efficiency of hyperthermic intraperitoneal chemotherapy (HIPEC) by a combination with a photosensitive drug in pediatric rhabdomyosarcoma

10.22541/au.164011101.14113880/v1 ◽

2021 ◽

Author(s):

Benedikt Wagner ◽

Anna Adamus ◽

Laura Hempfling ◽

Reza Vahdad ◽

Antje Haap-Hoff ◽

...

Keyword(s):

Animal Model ◽

Photodynamic Therapy ◽

Intraperitoneal Chemotherapy ◽

Hyperthermic Intraperitoneal Chemotherapy ◽

Ki 67 ◽

Tissue Samples ◽

Proliferation Capacity ◽

Tumor Dissemination ◽

Cell Layers

Background: Cytoreductive surgery (CRS) in combination with hyperthermic intraperitoneal chemotherapy (HIPEC) is an option in advanced peritoneal sarcomatosis. Nevertheless, CRS and HIPEC are not successful in all patients. An enhancement of HIPEC using photodynamic therapy might be beneficial. Therefore, a combination of the photosensitizer Hypericin (HYP) with HIPEC was evaluated in an animal model. Procedure: An established HIPEC animal model for rhabdomyosarcoma (NOD/LtSz-scid IL2Rγnullmice, n=80) was used. All groups received HYP (100 µg/200 µl) intraperitoneally with and without cisplatin-based (30 or 60 mg/m2) HIPEC (37 or 42 °C, for 60 min) (five groups, each n=16). Tumor dissemination was documented visually and by using HYP-based fluorescence guidance. HYP-based photodynamic therapy (PDT) of the tumor was performed. Finally, tissue samples were evaluated regarding proliferation (Ki-67) and apoptosis (TUNEL). Results: HYP uptake even in smallest tumor nodes (< 1 mm) was found. HYP-based fluorescence guidance allowed a better tumor detection in comparison to visual inspection. Immunohistochemistry revealed HYP penetration across the tumor surface. HYP-based PDT without HIPEC induced marginal apoptotic effects at the tumor surface. Combining HYP with HIPEC revealed cisplatin concentration dependent decrease in proliferation capacity and induction of apoptosis across determined cell layers of the tumor surfaces. Conclusion: HYP as fluorescent photosensitizer offers an intraoperative diagnostic advantage detecting intraperitoneal tumor dissemination. The combination of HYP and cisplatin-based HIPEC was feasible in vivo showing enhanced effects on tumor proliferation and apoptosis induction across the tumor surface. Further studies combining HYP and HIPEC will follow to establish a clinical application.

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The Temperature-Dependent Effectiveness of Platinum-Based Drugs Mitomycin-C and 5-FU during Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Colorectal Cancer Cell Lines

Cells ◽

10.3390/cells9081775 ◽

2020 ◽

Vol 9 (8) ◽

pp. 1775 ◽

Cited By ~ 2

Author(s):

Roxan F.C.P.A. Helderman ◽

Daan R. Löke ◽

Jan Verhoeff ◽

Hans M. Rodermond ◽

Gregor G.W. van Bochove ◽

...

Keyword(s):

Colorectal Cancer ◽

Dna Damage ◽

Mitomycin C ◽

Cell Lines ◽

Cell Cultures ◽

Intraperitoneal Chemotherapy ◽

Hyperthermic Intraperitoneal Chemotherapy ◽

Drug Uptake ◽

Temperature Dependent ◽

2D And 3D

Cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment with curative intent for peritoneal metastasis of colorectal cancer (CRC). Currently, there is no standardized HIPEC protocol: choice of drug, perfusate temperature, and duration of treatment vary per institute. We investigated the temperature-dependent effectiveness of drugs often used in HIPEC. Methods: The effect of temperature on drug uptake, DNA damage, apoptosis, cell cycle distribution, and cell growth were assessed using the temperature-dependent IC50 and Thermal Enhancement Ratio (TER) values of the chemotherapeutic drugs cisplatin, oxaliplatin, carboplatin, mitomycin-C (MMC), and 5-fluorouracil (5-FU) on 2D and 3D CRC cell cultures at clinically relevant hyperthermic conditions (38–43 °C/60 min). Results: Hyperthermia alone decreased cell viability and clonogenicity of all cell lines. Treatment with platinum-based drugs and MMC resulted in G2-arrest. Platinum-based drugs display a temperature-dependent synergy with heat, with increased drug uptake, DNA damage, and apoptosis at elevated temperatures. Apoptotic levels increased after treatment with MMC or 5-FU, without a synergy with heat. Conclusion: Our in vitro results demonstrate that a 60-min exposure of platinum-based drugs and MMC are effective in treating 2D and 3D CRC cell cultures, where platinum-based drugs require hyperthermia (>41 °C) to augment effectivity, suggesting that they are, in principle, suitable for HIPEC.

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