Studies on the expression of hematopoietic growth factor modulated by Egr-1 promoter sequence in transcriptional targeting by chemotherapeutic agents / 解放军医学杂志

ABSTRACT

Objective To explore the chemotherapeutic agents-induced modulating effects of Egr-1 promoter sequence on GM-CSF expression and its protective effect against injury to haematopoiesis due to chemotherapy.Methods Human GM-CSF cDNA and enhanced green fluorescent protein(EGFP) cDNA were linked to internal ribosome entry site(IRES) respectively,and then recombined to pCIneo vector containing Egr-1 promoter(Egr-EG).The vector was transferred into human bone marrow stromal cell line HFCL by lipofection,and the HFCL/EG cells were then finally constructed.MTT assay was performed to determine the effects of cisplatin(DDP),5-fluorouracil(5-FU),gemcitabine(GEM) and paclitaxel(PTX) on the survival rates of HFCL/EG and HFCL cells,and the IC50 of such agents against HFCL/EG and HFCL cells were calculated.The percentage of HFCL/EG cells which positively expressed EGFP was assessed by both flow cytometry and inverted fluorescence microscope.The effects of the active oxygen inhibitor N-acetylcysteine(NAC) on the expression of GM-CSF,which was modulated by promotor Egr-1,were detected by ELISA.The effects of HFCL/EG supernatant on CFU-GM after being exposed to chemotherapeutic agents were examined.Results With different sensitivity to DDP,5-FU,GEM and PTX,HFCL/EG cells were successfully constructed.The drugs showed higher IC50 value against HFCL/EG cells than HFCL cells(P