Absent in melanoma 2 (AIM2) has been reported to be an important inflammasome component that exerts tumor suppression in several tumors. However, whether CCL19/CCR7/AIM2 is involved in the progression of GC still remains unclear. Quantitative real-time and ELISA assay were used to determine the expressions of AIM2, CCL19 and CCR7 in GC tissues and cell lines. CCK-8, Edu staining, flow cytometry, Transwell assay, and tumorigenesis in nude mice were used to explore the function of AIM2 and CCL19 in vitro and in vivo. Apoptosis and inflammation-related biomarkers were detected by Western blot and ELISA assay. H&E staining was used to assess the histological changes in the subcutaneous tumor model. Immunohistochemistry (IHC) was used to evaluate the expression of Ki-67. We found that expression levels of AIM2, CCL19 and CCR7 were obviously lower in early GC tissues than those in progressive GC tissues. In vitro assays revealed that CCL19 treatment could enhance the suppressive effects of AIM2 overexpression on cell proliferation, migration, and invasion through CCR7. An in vivo assay also demonstrated that silencing of AIM2 reversed the suppressive effects of CCL19 on tumor growth. Collectively, CCL19 overexpression significantly inhibited GC cell proliferation and tumor growth in vitro and in vivo by up-regulating the CCR7/AIM2 pathway. Thus, CCL19 activated CCR7/AIM2 signaling pathway and it may be a potential therapeutic approach for GC therapy.
Keywords: AIM2; CCL19/CCR7; Gastric cancer; Inflammation; Tumor growth.