BACKGROUNDTo investigate the expression of the SOCS3 gene and its effect on proliferation of A549 cells.

METHODSA549 cells were cotransfected with pEFSOCS3 and pSV2neo by liposome, then G418 was used to screen the positive cells. Expression of SOCS3 mRNA and protein was detected by RT-PCR and immunocytochemistry respectively before and after transfection. MTT assay was used to detect the cell growth. Flow cytometric DNA analysis was used to determine the cell cycle.

RESULTSRT-PCR and immunocytochemistry showed that no expression of SOCS3 mRNA and protein was detected in A549 cells before transfection, but a stable expression of SOCS3 gene was observed after transfection with SOCS3 gene. Compared with control group, growth of A549 cells transfected with SOCS3 gene was significantly suppressed, with a suppressive rate of 41.07%. The cells at G₀/G₁ cell phases increased, and those at S and G₂/M phases decreased significantly after transfection.

CONCLUSIONSSOCS3 protein might inhibit the proliferation of A549 cells by negatively regulating cellular signal pathways.