Cisplatin exhibits superiority over MMC as a perfusion agent in a peritoneal mesothelioma patient specific organoid HIPEC platform

Abstract

Peritoneal mesothelioma (PM) is a rare malignancy with poor prognosis, representing about 10-15% of all mesothelioma cases. Herein we apply PM patient-derived tumor organoids (PTOs) in elucidating personalized HIPEC responses to bypass rarity of disease in generating preclinical data. Specimens were obtained from PM patients undergoing cytoreductive surgery with HIPEC. PTOs were fabricated with tumor cells suspended in ECM-hydrogel and treated with HIPEC regimen parameters. Viability and characterization analyses were performed post-treatment. Treatment efficacy was defined as ≥ 50% viability reduction and p < 0.05 compared to controls. From October 2020 to November 2022, 17 tumors from 7 patients were biofabricated into organoids, with 16/17 (94.1%) sites undergoing comparative 37° and 42° treatments with cisplatin and mitomycin C (MMC). Hyperthermic cisplatin and MMC enhanced cytotoxicity which reduced treatment viability by 25% and 22%, respectively, compared to normothermia. Heated cisplatin displayed the greatest cytotoxicity, with efficacy in 12/16 (75%) tumors and an average viability of 38% (5-68%). Heated MMC demonstrated efficacy in 7/16 (43.8%) tumors with an average treatment viability of 51% (17-92.3%). PTOs fabricated from distinct anatomic sites exhibited site-specific variability in treatment responses. PM PTOs exhibit patient and anatomic location treatment responses suggestive of underlying disease clonality. In PM organoids cisplatin is superior to MMC in HIPEC.

Figure 1

Fabrication of mesothelioma tumor organoids for HIPEC testing. Created with www.BioRender.com (created June 2023).

Figure 2

PTO sets demonstrate variable response to treatment in different patients using (a) Cell-Titer Glo and (b) LIVE/DEAD Imaging where green, living cells and red, dead cells.

Figure 3

Summary of all PTO Cell-Titer Glo© results.

Figure 4

Variability in PTO treatment response between mesothelioma implants from Patient 6 with biphasic histologic subtype, suggesting heterogenous tumor cell populations when comparing implant tumor cells from (a) colon (epithelioid) and (b) ovary (sarcomatoid) using analyses (i) Cell-Titer Glo, (ii) LDH quantification and (iii) LIVE/DEAD imaging.

Figure 5

(a) Increased localization of DNA damage response to nucleus. Figure demonstrates the increase of DNA damage markers including 53BP1, phosphorylated RAD51 and yH2AX to the nucleus (DAPI), suggesting increased damage response in these cells. (b) Overlap of DNA damage markers (TxRed) in CK7+ expressing cells (FITC), displaying total number of CK7+ cells with DNA damage. (c) Overlap of DNA damage on nucleus (DAPI), displaying total number of cells with measurable DNA damage.