Effects of Danshen Injection （丹参注射液） on Inhibiting Proliferation and Inducing Apoptosis through Down-Regulation of Mutant JAK2 Gene and Its Protein Phosphorylation in Human Erythroid Leukemic Cells

Objective： To explore the effects of Danshen Injection （丹参注射液） on inhibition proliferation, inducing apoptosis and its possible mechanisms on human erythroid leukemic （HEL） cells. Methods： The commercial Chinese patent medicine of Danshen Injection was extracted and isolated from Chinese herb of Salvia miltiorrhiza bung. The inhibition effects of proliferation were assayed by 3-（4,5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （M＇l-r） method in HEL cells treated by Danshen Injection at various concentrations for 48 h. The cellular apoptosis was observed in morphology, analyzed by flow cytometry with annexin V and propidium iodide （PI） staining, and examined by DNA degradation ladder on agarose gel electrophoresis. Meanwhile, the expression levels of mutant Janus kinasez （JAK2） gene and phosphorylation-JAK2 （P-JAK2） protein were detected by allele specific-polymerase chain reaction and Western blot. ]Results： The proliferation of HEL cells was effectively inhibited by Danshen Injection in a dose-dependent manner, with suppression rates from 19.46 ± 2.31% to 50.20 ± 5.21%. Typical apoptosis cells was observed in Danshen Injection treated HEL cells, the rates of annexin V positive cells increased obviously in a dose-dependent manner, as well as the DNA degradation ladder of apoptosis revealed on gel electrophoresis. The expression levels of mutant JAK2 gene and P-JAK2 protein reduced gradually with increasing dosage of Danshen injection. Conclusion： Danshen Injection could not only significantly inhibit the proliferation, but also induce apoptosis in HEL cells; down-regulation of the mutant JAK2 gene and P-JAK2 protein expressions are probably one of its molecular mechanisms.