Abstract: Objective To detect the level of Chemokine(C-C motif) ligand 22(CCL22) expression level in serum of gastric cancer,and analyze its relationship with the development of gastric.
Methods Fifty-five gastric patients and 30 healthy controls were enrolled in the present study.Peripheral blood of gastric cancer patients and healthy controls was collected,respectively.Total RNA in PBMCs was extracted by TRIzol.Then RNA was reversely transcribed into cDNA by reverse transcription PCR.CCL22 mRNA level in PBMCs was assayed by real-time PCR method.CCL22 protein level in serum was detected by ELSIA.Migration assay was used to evaluate the chemotactic effect of CCL22 on gastric cancer cells.
Results CCL22 RNA expression level in serum of gastric cancer patients was higher than that in healthy controls(P<0.05).CCL22 protein expression level in serum of gastric cancer patients was (1401.67±481.12)pg/ml,which was significantly higher than that in healthy controls[(500.08±100.51)pg/ml](P<0.05).Furthermore,the increase of CCL22 protein expression level in serum was in accordance with the clinical stage of gastric cancer.CCL22 could induce the migration of gastric cancer cells in a dose-dependent manner.
Conclusion Serum CCL22 expression in gastric cancer patients was increased.CCL22 had a chemotactic effect on gastric cancer cells.We  think that CCL22 might be involved in the development of gastric cancer.

Key words: gastric cancer, CCL22, peripheral blood