An experimental model for ovarian cancer: propagation of ovarian cancer initiating cells and generation of ovarian cancer organoids

Abstract

Background Ovarian cancer (OC) is the most lethal gynecological cancer due to the recurrence of drug-resistance. Cancer initiating cells (CICs) are proposed to be responsible for the aggressiveness of OC. The rarity and difficulty of in vitro long-term cultivation of CICs challenge the development of CIC-targeting therapeutics. Reprogramming cancer cells into induced cancer initiating cell (iCICs) could be an approach to solve these. Several inducible CICs have been acquired by activating the expression of stemness genes in different cancer cells. However, few reports have demonstrated the feasibility in OC. Methods Patients with primary OC receiving surgery were enrolled. Tumor tissue were collected, and OCT4, SOX2, and NANOG expressions were assessed by immunohistochemistry (IHC) staining to investigate the association of stemness markers with overall survival (OS). An high-grade serous ovarian cancer (HGSOC) cell line, OVCAR-3 was reprogrammed by transducing Yamanaka four factors OCT4, SOX2, KLF4 and MYC (OSKM) to establish an iOCIC model, iOVCAR-3-OSKM. CIC characteristics of iOVCAR-3-OSKM were evaluated by RT-PCR, sphere formation assay and animal experiments. Drug-resistance and migration ability were accessed by dye-efflux activity assay, MTT assay and migration assay. Gene profile was presented through RNA-sequencing. Lineage differentiation ability and organoid culture were determined by in vitro differentiation assays. Results In OC patients, the co-expression of multiple stem-related transcription factors (OCT4, SOX2, and NANOG) was associated with worse OS. iOVCAR-3-OSKM cells generated by reprogramming successfully exhibited stemness characteristics with strong sphere-forming and tumorigenesis ability. iOVCAR-3-OSKM cells also showed malignant potential with higher drug resistance to chemodrug, Paclitaxel (PTX) and migration ability. iOVCAR-3-OSKM was maintainable and expandable on feeder-dependent culture condition, it also preserved ovarian lineage differentiation abilities, which could well differentiate into OC cells with CK-7 and CA125 expressions and develop into an organoid mimic poor prognostic OC histological feature. Conclusions The establishment of iOVCAR-3-OSKM not only allows us to fill the gap in the information on induced CICs in OC but also provides a potential strategy to develop personalized CICs and organoid models for treating OC in the near future.

The occurrence and development of induced pluripotent stem cells

“…Many drugs and candidate drugs, such as cancer drugs, have achieved good results in animals but have had unexpected side effects on the human body and have not entered the market. The application of human pluripotent stem cells has potentially solved this problem, and reprogramming cancer cells into inducible cancer-initiating cells (iCICs) may be a way to address these issues ( Li et al, 2017 ; Verusingam et al, 2017 ; Bindhya et al, 2021 ; Taguchi et al, 2021 ; Ahn et al, 2022 ; Canals et al, 2022 ; Chen et al, 2022 ). This approach not only provides rich and stable human samples but also greatly reduces the cost of early detection of human toxic side effects in drug development.…”

Patient-Derived Organoids: The Beginning of a New Era in Ovarian Cancer Disease Modeling and Drug Sensitivity Testing

“…These cells were generated from the HGSOC cell line OVCAR-3 after reprogramming with the Yamanaka factors OCT4, SOX2, KLF4 and MYC (OSKM). The iOVCAR-3-OSKM organoids recapitulate successfully the histopathology of OC and may represent a valuable model for the study of OC pathogenesis [46]. OC organoids are not only prepared from primary or metastatic tumor, but also from body fluids containing OC cells.…”