반하 추출물의 종양연관대식세포 조절을 통한 암세포 이동능 저해 효과

Abstract

The tuber of Pinellia ternata (Thunb.) Brei (TPT) used in traditional Oriental medicine for the treatment of cough, sputum, vomiting, and insomnia, possesses antioxidant, antibacterial, and anti-inflammatory effects. Although recent studies have reported the anticancer effects of TPT in several cancer cells, it is still unclear whether TPT regulates tumor-associated macrophage (TAM) characterized by the immunosuppressive M2 macrophage phenotype. Our results showed that the ethanol extract of TPT (ETPT) suppressed the migration of RAW264.7 mouse macrophage cells and THP-1 human monocytes differentiated into macrophages towards the conditioned media (CM) collected from lung cancer cells, suggesting that ETPT would attenuate the recruitment of macrophages into tumors. In addition, ETPT suppressed the interleukin (IL)-4 or IL-6-induced M2 macrophage polarization in RAW264.7 cells. ETPT treatment not only downregulated the mRNA expression of M2 macrophage markers including arginase-1, mannose receptor C type 1 (MRC-1), and IL-10, but also inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and STAT6, general regulators of M2 macrophage polarization. Finally, the transwell assay results showed that the CM from M2-polarized RAW264.7 cells increased the migration of mouse lewis lung carcinoma (LLC) cells, while those from RAW264.7 cells co-treated with ETPT and IL-6 significantly reduced the migration of LLC cells. Taken together, our observations clearly demonstrate that ETPT suppressed the cancer cell migration by regulating macrophage recruitment and M2 macrophage polarization.