Figure 2. Ovarian cancer epithelial markers and morphologic characteristics in parent tumors are preserved over multiple mouse passages.

(A) BRCA^MUT patient-derived-xenograft (PDX) models (WO-2, WO-3) and 2 BRCA^WT PDX models (WO-4, WO-20) were evaluated by H&E and immunohistochemistry for epithelial ovarian cancer markers. PAX8 (paired box 8, nuclear stain), CK7 (cytokeratin 7, cytoplasmic stain), and ER (estrogen receptor, nuclear stain) in parent tumor and matched PDXs up to mouse passage 3 (MP1–MP3) are shown. Magnification is ×10 for large panels and ×100 for inserts. (B) Five matched BRCA^MUT patient/PDXs and 5 matched BRCA^WT patient /PDXs were reviewed for SET (solid, pseudoendometrioid, and translational cell carcinoma-like) morphology in a blinded fashion. WO-4 (BRCA^WT), WO-2-1 (BRCA2^MUT), and WO-3-1 (BRCA1^MUT) representative parent and PDX tumors of MP1, MP2, and MP3 H&E sections shown demonstrating SET criteria in BRCA^MUT and not in BRCA^WT tumors. Parent WO-2-1 tumor showed micropapillary features, while the MP1–MP3 tumors showed both micropapillary and solid architecture. Magnification is ×10 for all panels.