12Z Cells

The 12Z cell line is an immortalized human endometriotic epithelial cell model derived from peritoneal endometriotic lesions. It was originally established by transfecting primary endometriotic epithelial cells with the SV40 large T antigen, enabling extended proliferative capacity. The 12Z cells are cytokeratin-positive and E-cadherin-negative, distinguishing them as an epithelial-like population with an invasive phenotype. These cells have been shown to exhibit high migratory and invasive behavior in vitro, similar to metastatic carcinoma cells, and express N-cadherin, a cadherin associated with increased invasiveness and motility. This molecular profile supports their use in studying invasion mechanisms relevant to endometriosis and parallels seen in cancer biology. Functionally, 12Z cells express genes involved in estrogen and progesterone signaling, extracellular matrix remodeling, angiogenesis, cytokine production, and prostaglandin E2 (PGE2) biosynthesis and signaling. They exhibit elevated activity of matrix metalloproteinases MMP-2 and MMP-9, which are critical for degrading extracellular matrix components and facilitating tissue invasion. Furthermore, 12Z cells produce high levels of PGE2, an inflammatory mediator implicated in the pathophysiology of endometriosis. These features, along with their responsiveness to steroid hormones, make 12Z cells an effective in vitro model for dissecting the molecular underpinnings of endometriotic lesion establishment, invasion, and hormonal regulation. Importantly, recent quality control studies have confirmed the genetic authenticity of 12Z cells through STR (short tandem repeat) profiling, mitigating previous concerns about cross-contamination and misidentification in endometriosis research. These cells, along with the closely related Z11 line, have been proposed as standard models for improving reproducibility and reliability in the field of reproductive biology and endometriosis research.