Single cell derived organoids capture the self-renewing subpopulations of metastatic ovarian cancer

Abstract

High Grade Serous Ovarian cancer (HGSOC) is a major unmet need in oncology, due to its precocious dissemination and the lack of meaningful human models for the investigation of disease pathogenesis in a patient-specific manner. To overcome this roadblock, we present a new method to isolate and grow single cells directly from patients' ascites, establishing the conditions for propagating them as single-cell derived ovarian cancer organoids (scOCOs). By single cell RNA sequencing (scRNAseq) we define the cellular composition of metastatic ascites and trace its propagation in 2D and 3D culture paradigms, finding that scOCOs retain and amplify key subpopulations from the original patients' samples and recapitulate features of the original metastasis that do not emerge from classical 2D culture, including retention of individual patients' specificities. By enabling the enrichment of uniquely informative cell subpopulations from HGSOC metastasis and the clonal interrogation of their diversity at the functional and molecular level, this method transforms the prospects of precision oncology for ovarian cancer.

Human-Derived Model Systems in Gynecological Cancer Research

“…Utilizing a novel single-cell DNA sequencing analysis, it has been confirmed that the organoids reliably maintain the tumor heterogeneity in culture, even after prolonged passaging [69]. A promising preprint on single-cell transcriptomic analysis of high-grade ovarian cancer organoids further supports the preservation of tumor heterogeneity in culture [74]. These recent studies have shown that tumor organoids recapitulate the histological and genomic features of original tumor subtypes and capture intra-and interpatient heterogeneity.…”

Exploiting epigenetic dependencies in ovarian cancer therapy

“…124 Patient-derived organoid models have recently been developed for ovarian cancer, through several approaches that recapitulate the genomic landscape and tumor heterogeneity of primary ovarian cancer tumors. 11,125 One of the key challenges in ovarian cancer is the capacity of a small subpopulation of quiescent cells to evade treatment, and results in post-chemotherapy relapse. 126 It is becoming clear that a combination of therapies targeting individual susceptibilities of cancer subpopulations may lead to greater disease-free survival rates.…”

Current concepts in tumour-derived organoids

“…26 Although the tissue for organoid culture is most commonly derived from surgical resection specimens, 27,28 organoid cultures have been successfully established from other tissue sources, for example, endoscopic biopsy from Barrett's oesophagus, 27 needle biopsy for hepatocellular carcinoma, 29 endoscopic ultrasound-scan-guided fine-needle biopsy for pancreatic ductal adenocarcinoma 30 and ascitic fluid for both pancreatic and ovarian cancers. 25,31 Successful tumour organoid cultures can therefore be generated from a small amount of biological material and from cancers that are difficult to access in the clinical setting. Previously, the interval between specimen collection and successful establishment of organoid culture has been dictated by the viability of fresh samples, which has limited the time, location and demographic from which a patient sample can be taken, but Tsai and colleagues published a robust method in to cryopreserve fresh human biopsy tissue and later thaw the specimen to generate gastrointestinal organoid cultures, thus overcoming this limitation.…”