Yingna Chen, Liuyu Sun, Yitong Luo, Ying Jiang, Yan Zhou
School of Pharmacy, Changzhou University, Changzhou, Jiangsu 213164, China
*Corresponding Author: Yan Zhou, Yingna Chen; E-mail: 2897044877@qq.com, chenyingna@cczu.edu.cn
Abstract
Objective
This study aims to investigate the effects of ginsenoside Rg3 on the proliferation, migration, and invasion of gastric cancer (GC) cells and its underlying molecular mechanism.
Methods
Normal gastric mucosal epithelial cells (GES-1) and GC cell lines were cultured. GC cells were treated with ginsenoside Rg3, and the expression of TREM2 (triggering receptor expressed on myeloid cells 2) was detected by qRT-PCR (quantitative reverse transcription PCR) or western blot. THP-1 cells were differentiated into M0 macrophages using PMA (phorbol 12-myristate 13-acetate), and then polarized towards an M2 phenotype (TAMs, tumor-associated macrophages) using IL-4 and IL-13. TAMs were co-cultured with ginsenoside Rg3-pretreated cells. The expression of M1 macrophage markers[TNF-α (tumor necrosis factor-α), IL-6 (interleukin-6), iNOS (nitric oxide synthase 2)] and M2 macrophage markers [(CD206, CD163, IL-10 (interleukin-10)] was detected by qRT-PCR. Immunofluorescence was used to assess changes in the M1 marker CD163 and the M2 marker CD68. Cell viability was measured using CCK-8 assay, cell proliferation by colony formation assay, and cell migration and invasion by Transwell assay. To validate the mechanism, TREM2 was overexpressed in the GC cell line BGC-823 combined with ginsenoside Rg3 treatment.
Results
TREM2 expression was elevated in GC. Ginsenoside Rg3 treatment inhibited TREM2 expression in GC cells. Furthermore, ginsenoside Rg3 promoted the polarization of TAMs towards the M1 phenotype, thereby reducing GC cell viability and inhibiting GC cell proliferation, migration, and invasion. Overexpression of TREM2 in GC reversed the promoting effect of ginsenoside Rg3 on M1 polarization of TAMs, while simultaneously increasing GC cell viability, proliferation, migration, and invasion capabilities.
Conclusion
Ginsenoside Rg3 inhibits TREM2 expression, promotes the polarization of TAMs towards the M1 phenotype, and consequently suppresses the proliferation, migration, and invasion of gastric cancer cells.
Keywords: Gastric cancer; Ginsenoside Rg3; TREM2; TAMs; Macrophage polarization