Sphingosine-1-Phosphate Receptor 1 Promotes Ovarian Cancer Tumorsphere Proliferation and Metastasis

Area of Science:

• Oncology
• Molecular Biology
• Cancer Metastasis

Background:

• High-grade serous ovarian cancer (HGSOC) has a poor prognosis, with half of diagnosed women succumbing annually.
• Malignant ascites are present in nearly all HGSOC cases at diagnosis and are associated with poor outcomes.
• Ovarian cancer cells in ascites form tumorspheres, which are the primary metastatic units, but the underlying mechanisms are poorly understood.

Purpose of the Study:

• To investigate the molecular mechanisms by which ovarian cancer tumorspheres survive and proliferate within the ascites environment.
• To identify key pathways that promote the metastatic potential of HGSOC tumorspheres.

Main Methods:

• Analysis of tumorspheres isolated from ascites of treatment-naïve HGSOC patients.
• Utilized three-dimensional spheroid models in vitro and in vivo.
• Investigated the role of the sphingosine-1-phosphate (S1P) and its receptor S1PR1 axis.

Main Results:

• The sphingosine-1-phosphate (S1P) ligand and its receptor S1PR1 axis are crucial for ovarian tumorsphere survival and proliferation.
• This axis promotes an autocrine positive loop, driving proliferation via MEK1/2-ERK activation.
• The S1P-S1PR1-MEK1/2 pathway provides a selective advantage to tumorspheres in ascites, enhancing metastatic potential.

Conclusions:

• The S1P-S1PR1-MEK1/2 pathway is a key driver of ovarian tumorsphere proliferation and survival in the ascites microenvironment.
• Targeting this pathway may represent a novel therapeutic strategy to reduce HGSOC metastasis.