Prostaglandin 12 analog suppresses lung metastasis by recruiting pericytes in tumor angiogenesis

Prostaglandin I-2 (PGI(2)) agonist has been reported to reduce tumor metastasis by modifying tumor angiogenesis; however, the mechanisms of how PGI(2), affects the endothelial cells or pericytes in tumor vessel maturation are still unclear. The purpose of this study was to clarify the effects of PGI(2), on tumor metastasis in a mouse lung metastasis model using Lewis lung carcinoma (LLC) cells. The mice were treated continuously with beraprost sodium (BPS), a PGI(2), analog, for 3 weeks and then examined for lung metastases. The number and size of lung metastases were decreased significantly by BPS treatment. In addition, scanning electron microscopy and immunohistochemistry revealed that BPS increased the number of tumor-associated pericytes and improved intratumor hypoxia. Collectively, this study suggests that BPS attenuated vascular functional maturation in metastatic tumors.