Ovarian Cancer Patient-Derived Organoids Used as a Model for Replicating Genetic Characteristics and Testing Drug Responsiveness: A Preliminary Study.

Abstract

This study aimed to explore the role of ovarian cancer patient-derived organoids (PDOs) in their replicating genetic characteristics and testing drug responsiveness. Ovarian cancer PDOs were cultured in Matrigel with a specialized medium. The successful rate and proliferation rate were calculated. Morphology, histology, and immunohistochemistry (IHC) (PAX8, P53, and WT1) were used to identify the tumor characteristics. Gene sequencing, variant allele frequency (VAF), and copy number variation were used to explore the mutation profile. The sensitivity to chemodrugs (carboplatin, paclitaxel, gemcitabine, doxorubicin, and olaparib) was conducted. Successful generation of organoids occurred in 54% (7/13) of attempts, encompassing 4 high-grade serous carcinomas (HGSC), 1 mucinous carcinoma (MC), 1 clear cell carcinoma (CCC), and 1 carcinosarcoma. The experiments used six organoids (3 HGSC, 1 CCC, 1 MC, and 1 carcinosarcoma). The derived organoids exhibited spherical-like morphology, and the diameter ranged from 100 to 500 μm. The histology and IHC exhibited the same between organoids and primary tumors. After cryopreservation, the organoid's growth rate was slower than the primary culture (14 days vs 10 days, P < 0.01). Targeted sequencing revealed shared DNA variants, including mutations in key genes, such as BRCA1, PIK3CA, ARID1A, and TP53. VAF was similar between primary tumors and organoids. The organoids maintained inherited most copy number alterations. Drug sensitivity testing revealed varying responses, with carcinosarcoma organoids showing higher sensitivity to paclitaxel and gemcitabine than HGSC organoids. Our preliminary results showed that ovarian cancer PDOs could be successfully derived and histology, mutations, and diverse copy numbers of genotypes could be faithfully captured. Drug testing could reveal the individual PDO's responsiveness to drugs. PDOs might be as valuable resources for investigating genomic biomarkers for personalized treatment.