Cationic lipids enhanced cellular uptake and activity of bcl-2 antisence oligodeoxynucleotide G3139 in HL-60 cells

AIM: To explore the effect of cationic lipid 1, 3-dioleoyloxy-2-(6-carboxy- spermyl)-propylamid (DOSPER) on cellular uptake and activity of bcl-2 antis ense oligodeoxynucleotide G3139 in HL-60 cells. METHODS: The cell-associate d mean fluorescence intensity and the percentage of cells with positive sta ining for Bcl-2 were measured by flow cytometry. The subcellular distributi on of fluorescein isothiocyanate ( FITC)-labeled G3139 was observed by fluo rescence microscope and the bcl-2 mRNA level was detected by reverse transc ription polymerase chain reaction (RT-PCR). RESULTS: (I) DOSPER increased c ellular uptake of G3139 into HL-60 cells greatly. When DOSPER/G3139 (mug : mug) was 2:1, the uptake of G3139 reached top after treatment for 2 h and i ncreased about 20 times compared with application of G3139 alone. In the pr esence of DOSPER, G3139 was localized in nucleus and cytosol with a bright spotted fluorescence staining. However, G3139 was localized in cytoplasm wi th faint fluorescence in the absence of DOSPER. (2) Cell-associated G3139 c ould be effluxed out of cells. After treated with G3139 in the presence of DOSPER for 4 h, the cell-associated G3139 could be fitted by C(t) = 68.2e(- 0-60 t) +31.8e(-0-02) (t) (% of initial value), with a half-life of approxi mately 1. I h. In the absence of DOSPER, the cell-associated G3139 could be fitted by C ( t) = 64. 8e(-2.27) (t) + 35.2e(-0-04 t), with a half-life of about 18 min. (3) In the presence of DOSPER, G3139 1.0 mu mol.L-1 speciall y reduced bcl-2 mRNA level, and Bcl-2 protein decreased from 97 % +/- 4 % t o 70.6 % +/- 2.1 %. CONCLUSION: DOSPER enhanced the activity of G3139 and i t might be attributed to increase of the cellular uptake and change of the subcellular distribution of G3139.