Objective    To explore whether there are suspension tumor spheres in human gastric BGC-823 cells

and investigate the expression of progastrin (Pro-GRP) in the tumor spheres.     Methods    Adherent cells were cultured by limit diluting and serum-free culture

then the existence of suspended cells that possessed the characteristic of stem cells was identified by colony formation capability assay. Flow cytometry was used to detect the expression of ABCG2 CD44 and CD166. The expression of Pro-GRP in the tumor spheres and the adherent cells was detected by ELISA

immunofluorescence and flow cytometry.      Results    The suspended tumor spheres were formed by limit diluting assay serum-free culture. The difference of colony formation was significant between suspended tumor spheres (37.63±5.99) and adherent cells (10.75±3.37) (P0.01). The expression of ABCG2 in suspended tumor spheres was obviously higher than adherent cells (57.17±3.49 vs 8.67±0.77

P0.01). The expression of Pro-GRP in suspended tumor spheres was markedly higher than adherent cells (73.37±9.42 vs 5.11±1.03

P0.01).     Conclusion    Tumor spheres exist in human gastric BGC-823 cells

and Pro-GRP expression is related to tumor spheres.