Characterization of ascites-derived tumor cells from an endometrial cancer patient

Abstract

Improved treatment outcomes for the endometrial cancer patient requires precision methods to investigate the biology of this disease and clinically relevant models to test treatment drugs. Hence, we applied a personalized platform to investigate whether in vitro and in vivo models could accurately predict effective treatment regimens. We successfully expanded ascites-derived tumor cells from an endometrial cancer patient with malignant ascites using ascites collected prior to chemotherapy treatment. Hematoxylin-eosin and immunohistochemistry staining of ascites-derived tumor cells confirmed the source of endometrial cancer cells. Ascites-derived tumor cells were sensitive to cisplatin and doxorubicin single-agent treatments in CCK-8 assay and 3-D culture, a condition that more closely mimics the in vivo environment. We further showed that ascites-derived tumor cells from this patient could form tumors in NOD/SCID mice with preserved morphological characteristics. A remarkable concordance between the clinical response of cisplatin and the results of in vitro and in vivo drug tests reflected the reliability of our personalized approach in this case. Together, our results indicated that an effective platform for ex vivo and in vivo culture of ascites-derived tumor cells from our endometrial cancer patient could be applied to identify treatment options, and may be commonly used in treating cancer patients with malignant ascites in the future.

Keywords: Ascites; drug sensitivity test; endometrial cancer; ex vivo culture; patient-derived xenograft model.

Figure 1

Tumor sites and treatment timelines in a 62‐year‐old woman with endometrial cancer and breast cancer. (a) Different tumor localizations for endometrial cancer, left breast cancer, malignant ascites, and clinical suspicion of thyroid carcinoma. Right panel, representative images of H&E staining and ultrasound (Yellow arrows mean tumor lesions). CK8, cytokeratin 8; ER, estrogen receptor; HER2, human epidermal growth factor receptor‐2; PR, progesterone receptor; WT1, Wilms’ tumor suppressor gene 1. (b) Treatment timeline. CBP, carboplatin; DDP(6), six cycles of cisplatin; DT, radiotherapy; GEM, gemcitabine; IPT, i.p. perfusion therapy; i.v., i.v. injection; T, paclitaxel; TAM, tamoxifen.

Figure 2

Representative images and drug sensitivity of cultured ascites‐derived tumor cells from a 62‐year‐old woman with endometrial cancer and breast cancer. (a) Representative images of H&E and immunohistochemistry staining. CK8, cytokeratin 8; pS6RP, phosphorylated S6 ribosomal protein; PTEN, phosphatase and tensin homolog; WT1, Wilms’ tumor suppressor gene 1. (b) Heat maps representing cell viability after treatment of selected anticancer drugs. Each concentration represents a twofold increase from the previous dose, with each concentration tested in triplicate. Conditions were optimized for highly repeatable testing of viability. (c) Ascites‐derived tumor cells were grown in 3‐D culture and treated with indicated drugs. Over 25 structures were scored for each drug. (d) Representative images of scored structures: intact, semi‐disintegrated, and disintegrated (Disint.).

Figure 3

Ascites‐derived tumor cells are tumorigenic and patient‐derived xenografts mirror patient response to therapy in a 62‐year‐old woman with endometrial cancer and breast cancer. (a) Ascites‐derived tumor cells enriched from the patient were injected into NOD/SCID mice. Representative images of H&E staining are shown. (b,c) Representative images of immunohistochemistry staining in primary endometrial cancer (b) and the patient‐derived xenograft model (c). CA125, cancer antigen 125; CK8, cytokeratin 8; PTEN, phosphatase and tensin homolog; WT1, Wilms’ tumor suppressor gene 1. (d) Prominent central necrosis in the treated group and immunohistochemistry staining of anti‐Ki67.

Figure 4

A reliable platform for cancer individualized medicine. The ex vivo culture of ascites‐derived tumor cells and in vivo models were developed for predicting potential effective treatment regimens. All methods ended in a recommendation for a specific therapy for a patient with malignant ascites on an individualized basis. Gene sequencing and immunohistochemistry (IHC) staining were part of a comprehensive approach to precise matching of novel therapies to patients. PDX, patient‐derived xenograft.