ABSTRACT
Fallopian tube epithelium (FTE) plays a critical role in reproduction and can be the site where High Grade Serous Ovarian Carcinoma (HGSOC) originates. Tumorigenic oviductal cells, which are the murine equivalent of human fallopian tube secretory epithelial cells (FTSEC), enhance testosterone secretion by the ovary when co-cultured with the ovary, suggesting that testosterone is part of the signaling axis between the ovary and FTSEC. Furthermore, testosterone promotes proliferation of oviductal cells. Oral contraceptives, tubal ligation, and salpingectomy, which are all protective against developing ovarian cancer, also decrease circulating levels of androgen. In the current study, we investigated the effect of increased testosterone on FTE and found that testosterone upregulates wingless-type MMTV integration family, member 4 (WNT4) and induces migration and invasion of immortalized human fallopian tube cells. We profiled primary human fallopian tissues grown in the microfluidic system SOLO-microfluidic platform -(MFP) by RNA sequencing and found that p53 and its downstream target genes, such as paired box gene 2 (PAX2), cyclin-dependent kinase inhibitor 1A (CDK1A or p21), and cluster of differentiation 82 (CD82 or KAI1) were downregulated in response to testosterone treatment. A microfluidic platform, the PREDICT-Multi Organ System (PREDICT-MOS) was engineered to support insert technology that allowed for the study of cancer cell migration and invasion through Matrigel. Using this system, we found that testosterone enhanced FTE migration and invasion, which was reversed by the androgen receptor (AR) antagonist, bicalutamide. Testosterone also enhanced FTSEC adhesion to the ovarian stroma using murine ovaries. Overall, these results indicate that primary human fallopian tube tissue and immortalized FTSEC respond to testosterone to shift expression of genes that regulate invasion, while leveraging a new strategy to study migration in the presence of dynamic fluid flow.
ABSTRACT
High grade serous ovarian cancers (HGSOC) predominantly arise in the fallopian tube epithelium (FTE) and colonize the ovary first, before further metastasis to the peritoneum. Ovarian cancer risk is directly related to the number of ovulations, suggesting that the ovary may secrete specific factors that act as chemoattractants for fallopian tube derived tumor cells during ovulation. We found that 3D ovarian organ culture produced a secreted factor that enhanced the migration of FTE non-tumorigenic cells as well as cells harboring specific pathway modifications commonly found in high grade serous cancers. Through size fractionation and a small molecule inhibitors screen, the secreted protein was determined to be 50-100kDa in size and acted through the Epidermal Growth Factor Receptor (EGFR). To correlate the candidates with ovulation, the PREDICT organ-on-chip system was optimized to support ovulation in a perfused microfluidic platform. Versican was found in the correct molecular weight range, contained EGF-like domains, and correlated with ovulation in the PREDICT system. Exogenous versican increased migration, invasion, and enhanced adhesion of both murine and human FTE cells to the ovary in an EGFR-dependent manner. The identification of a protein secreted during ovulation that impacts the ability of FTE cells to colonize the ovary provides new insights into the development of strategies for limiting primary ovarian metastasis.