Effect of tumor-associated macrophages on malignant biological behaviors of gastric cancer MGC-803 cells / 中国肿瘤生物治疗杂志

ABSTRACT

@# Objective: To investigate the effects of tumor-associated macrophages (TAM) on proliferation, migration, invation and apoptosis of gastric cancer MGC-803 cells and the possible mechanisms. Methods: Human monocyte THP-1 was cultured in vitro. After being added with PMA and IL-4, the levels of interleukin-12 (IL-12) and interleukin-10 (IL-10) in cell supernatant were detected by enzyme-linked immunosorbent assay (ELISA). MGC-803 cells at logarithmic phase and M2-type TAM cells were divided into single cell culture group, non-contact co-culture group and contact co-culture group according to different culture methods. MTT assay was used to detect the proliferation of MGC-803 cells, Transwell assay was used to detect cell migration and invasion, andAnnexin V-FITC/ PI staining flow cytometry was used to examine the apoptosis and cell cycle changes of MGC-803 cells; In addition, the mRNAand protein expressions of matrix metalloproteinase-9 (MMP-9) and MMP-2 were detected by Real-time fluorescence quantitative PCR (qPCR) and Western blotting. Results: Compared with PMA group, the level of IL-12 in cell supernatant of PMA+IL-4 group decreased significantly while the level of IL-10 increased significantly (all P<0.05), indicating THP-1 cells were successfully induced to differentiate into M2-type TAM. Compared with the single cell culture group, the non-contact co-culture group and the contact co-culture group exhibited (1) significantly increased proliferation rate of MGC-803 cells (P<0.05)； (2) increased number of migrated and invaded cells (all P < 0.05)； (3) significantly decreased apoptotic rate (P<0.05)； (4) increased proportion of S, G2 phase cells and decreased proportion of G1 phase cells (all P<0.05)；and (5) significantly increased mRNA and protein expressions of MMP-9 and MMP-2 (all P<0.05). Conclusion: TAM can promote the proliferation, migration and invasion of gastric cancer MGC-803 cells, relieve G1 phase arrest and reduce cell apoptosis, which may be related to the up-regulation of MMP-9 and MMP-2 expression in gastric cancer cells.