Association of mast cell infiltration with gastric cancer progression.

The present study aimed to determine the expression of mast cells, C-C motif chemokine ligand 2 (CCL-2) and C-C motif chemokine receptor 2 (CCR2) in gastric cancer tumor tissue; and the association of mast cells with the proliferation, migration, invasion and apoptosis of gastric cancer cells. In addition, whether the stem cell factor (SCF)/c-Kit pathway was associated with the secretion of CCL-2 by gastric cancer cells was explored. Flow cytometry analysis and immunohistochemistry were used to observe the relative number of mast cells, and reverse transcription-quantitative polymerase chain reaction and western blot analysis were utilized to determine the expression of CCL-2 and CCR2 mRNA and protein. Following the co-culture of the mast cell line HMC-1 and the gastric cancer cell line BGC-823, a Transwell assay was used to validate the effect of mast cells on the migration and invasion of gastric cancer cells. Furthermore, Cell Counting kit-8 and dual acridine orange/ethidium bromide fluorescent staining assays were performed to determine the proliferation and apoptosis of gastric cancer cells, following co-culture with mast cells. The expression of SCF and c-Kit were also determined with a western blot analysis. A specific phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin, was used to test the effect of PI3K inhibition on the secretion of CCL-2 in gastric cancer. The results demonstrated that the proportion of infiltrating mast cells, and the mRNA/protein expression of CCL-2 and CCR2, were significantly increased in tumor tissue relative to adjacent tissues. In addition, the migration and invasion of gastric cancer cells were significantly increased when mast cells were used as an attractant. When co-cultured with mast cells, the viability of gastric cancer cells was significantly increased and H