Epithelial ovarian cancer (EOC) patients frequently develop peritoneal metastasis, especially in the human omentum. However, the mechanism underlying this propensity remains unknown. A previous study found that human omental adipose-derived mesenchymal stem cells are potentially involved in ovarian cancer growth and metastasis, but the results were inconsistent and even contradictory. In addition, the underlying mechanisms of visceral adipose metastasis remain poorly understood. Here, our goal is to clarify the role and mechanism of human omental adipose-derived mesenchymal stem cells (HO-ADSCs) in EOC cancer growth and metastasis. We first found that human omental tissue conditioned medium (HO-CM) enhances EOC cell function. Subsequent coculture studies indicated that HO-ADSCs increase the growth, migratory and invasive capabilities of ovarian cancer cells. Then, we demonstrated that exosomes secreted by HO-ADSCs (HO-ADSC exosomes) enhanced ovarian cancer cell function, and further mechanistic studies showed that the FOXM1, Cyclin F, KIF20A, and MAPK signaling pathways were involved in this process. In addition, subcutaneous tumorigenesis and peritoneal metastatic xenograft experiments provided evidence that HO-ADSC exosomes promote ovarian cancer growth and metastasis in vivo. Finally, our clinical studies provided evidence that ascites from ovarian cancer patients enhance EOC cell line proliferation, migration, and invasion in vitro. The present study indicated that HO-ADSC exosomes are secreted into ascites and exert a tumor-promoting effect on EOC growth and metastasis, providing a new perspective and method to develop future novel therapeutic strategies for the treatment of ovarian cancer.
Keywords: ADSCs: Adipose-derived mesenchymal stem cells; EOC: Epithelial ovarian cancer; HE: Hematoxylin and eosin; HO-ADSC: Human omental Adipose-derived mesenchymal stem cell; HO-CM: Human omental tissue conditioned medium; IHC: Immunohistochemistry; MSC: Mesenchymal stem cell; PMX: Peritoneal metastatic xenograft; SBT: Subcutaneous tumorigenesis; TEM: Transmission electron microscopy; ascites; epithelial ovarian cancer; exosomes; exosomes secreted by HO-ADSCs: HO-ADSC exosomes; human omentum; mesenchymal stem cells; peritoneal metastasis; qRT-PCR: Quantitative real-time PCR.