Human fallopian tube epithelial organoids with TP53 mutation recapitulate features of serous tubal intraepithelial carcinoma (STIC).

OBJECTIVE

Serous tubal intraepithelial carcinoma (STIC) is the immediate precursor lesion for high-grade serous ovarian carcinoma (HGSOC) and harbors universal TP53 mutations. The lack of an appropriate in vitro model for STIC presents a major challenge in studying its pathogenesis. We aimed to develop a human in vitro model that mimics STIC lesions.

METHODS

Using CRISPR-Cas9 gene editing, we generated human fallopian tube epithelial organoids with TP53 loss-of-function mutations (TP53-/- FTOs). We characterized TP53-/- FTOs on a cellular and molecular level using immunofluorescence confocal imaging, copy number variation (CNV) analysis, and RNA sequencing.

RESULTS

TP53-/- FTOs recapitulated key features of STIC lesions. They exhibited increased proliferation and nuclear abnormalities, including nuclear enlargement and atypical mitotic figures. Copy number variation analysis revealed aneuploidy in some TP53-/- FTOs. Compared to unedited controls, TP53-/- FTOs demonstrated significant transcriptomic changes, including the downregulation of DNA repair genes and upregulation of epithelial-mesenchymal transition (EMT) pathways. Similar to STIC lesions, TP53-/- FTOs showed a marked reduction in ciliated cells and ciliogenesis-associated gene expression.

CONCLUSIONS

These findings suggest that p53 loss in FTOs promotes a proliferative and genomically unstable state that is conducive to carcinogenesis. The TP53-/- FTO model we have generated provides a valuable tool for studying early events in ovarian carcinogenesis and for developing new strategies for the early detection and prevention of ovarian cancer.