Abstract: Objective To study the effects of human insulin-like growth factor 1 (hIGF-1) gene transfection on the proliferation of NIH3T3 fibroblasts. Methods The plasmid of pcDNA3.1-hIGF-1 was transfected into NIH3T3 fibroblasts by using Lipofectin method. The positive cell clones were selected with G418 and cultured for 4 weeks. The stable expression of hIGF-1 in the positive cells was determined by in situ hybridization and immunocytochemical analysis. MTT assay and flow cytometer analysis were used to observe the proliferation of NIH3T3 fibroblasts. Results hIGF-1 mRNA and protein expressed in NIH3T3 fibroblasts transfected with pcDNA3.1-hIGF-1 by in situ hybridization and immunocytochemical analysis. MTT assay showed the A value of transfected NIH3T3 fibroblasts rose, compared with untransfected NIH3T3 fibroblasts group, the difference was significant (P<0.01). Cellular proportion in S period (59.3%) was increased and it in G₁ periods was decreased (27.2%) after transfection by flow cytometer measurement. Conclusion The stable expression of hIGF-1 in NIH3T3 fibroblasts transfected with pcDNA3.1-hIGF-1 is obtained. Gene transfection of hIGF-1 can stimulate the proliferation of NIH3T3 fibroblasts.

Key words: gene expression, fibroblasts, 3T3 cells, cell cycle