Establishment of immortalized ovarian stromal cell lines using Sendai virus vectors: a platform for studying tumor–stroma interactions and carcinogenesis

We aimed to generate immortalized stromal cell lines from the ovarian and fallopian tube tissues of a single patient using Sendai virus (SeV) vectors and identify candidate stromal genes involved in ovarian carcinogenesis. Tissues were collected from a 48-year-old woman with endometrioid borderline tumors and endometriomas. Primary cultures were established from the right ovarian endometrioma, left ovarian surface, bilateral fallopian tube, and endometrial surface. Immortalization was achieved using SeV vectors encoding human telomerase reverse transcriptase (TERT), B lymphoma Mo-MLV insertion region 1 homolog (Bmi-1), and Simian virus 40 large T antigen (SV40T). Morphologically, the established cells exhibited spindle-shaped fibroblast-like features and expressed stromal markers (Vimentin-positive, Keratin-negative), confirming their stromal origin. Genetic and molecular changes associated with immortalization were evaluated via chromosomal analyses, transcriptome sequencing, and reverse transcription-polymerase chain reaction (RT-PCR). SeV-infected stromal cell lines retained their proliferative capacity for over 25 passages, whereas non-infected primary cells lost their epithelial characteristics and underwent senescence after five passages. Chromosomal abnormalities were more prevalent in stromal cells derived from the ovarian endometriomas, suggesting early genomic instability. Transcriptomic profiling and RT-PCR revealed upregulation of matrix metallopeptidase 1 (MMP1), pregnancy-associated plasma protein A (PAPPA), and C-X-C motif chemokine ligand 1 in cyst-derived stromal cells compared to those from the normal ovary and fallopian tube, implicating these genes in extracellular matrix remodeling and tumor-stroma crosstalk. We established immortalized ovarian and fallopian tube stromal cell lines using SeV-based vectors. The cyst-derived stromal cells exhibited early chromosomal instability and overexpression of MMP1 and PAPPA, supporting their potential role in ovarian carcinogenesis. These immortalized stromal cell lines provide a novel and stable platform for mechanistic studies and may contribute to biomarker discovery and therapeutic target development in ovarian cancer.