CCL22 and IL-37 inhibit the proliferation and epithelial-mesenchymal transition process of NSCLC A549 cells

Abstract

In the present study, we aimed to investigate the effects of CC chemokine ligand 22 (CCL22) and interleukin-37 (IL-37) on the proliferation and epithelial-mesenchymal transition (EMT) of non-small cell lung cancer (NSCLC) A549 cells. pDsRed-CCL22 and pEGFP-IL-37 plasmids were constructed. A549 cells were divided into six groups: the control, the pDsRed-N1 blank plasmid, the pEGFP-C1 blank plasmid, the pDsRed-CCL22 plasmid, the pEGFP‑IL-37 plasmid and the pDsRed-CCL22 + pEGFP-IL-37 plasmid group. Expression levels and localization of CCL22 and IL-37 in cells were detected by confocal microscopy. Phase-contrast microscopy was applied for observing cellular morphology. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used for detecting the mRNA levels of vimentin, N-cadherin and E-cadherin, and their protein expression levels were tested using western blotting. Constructed plasmids expressed CCL22 and IL-37, both of which had a co-localization in the cell membrane. MTT assay and cell observation results revealed that CCL22 and IL-37 inhibited the proliferation and EMT process of the A549 cells. The results of RT-qPCR and western blotting revealed that decreased vimentin and N-cadherin mRNA and protein expression levels, and increased E-cadherin mRNA and protein expression levels were found in the pDsRed-CCL22 plasmid, pEGFP-IL-37 plasmid and pDsRed‑CCL22 + pEGFP‑IL-37 plasmid groups when compared with the control, the pDsRed-N1 blank plasmid and the pEGFP-C1 blank plasmid groups (all P<0.05), and decreased vimentin and N-cadherin mRNA and protein expression levels and increased E-cadherin mRNA and protein expression levels were found in the pDsRed‑CCL22 + pEGFP‑IL-37 plasmid group when compared with the pDsRed-CCL22 plasmid and the pEGFP‑IL-37 plasmid groups (all P<0.05). CCL22 and IL-37 with a co-localization in the A549 cells inhibited the proliferation and EMT process in A549 cells. The antitumor effects of CCL22 and IL37 provide a strategy for the treatment of NSCLC.