Effect of interferon on HEL cell apoptosis and JAK2 V617F mutation gene expression / 实用医学杂志

Objective To observe the effect of Interferon-α2b on HEL cells (human erythroleukemia cell line) growth, apoptosis and JAK2 V617F mutation gene expression. Methods HEL cells were placed in RPMI1640 containing 10% FBS and incubated in a cell incubator. Cells in the logarithmic growth phasem were collected, adjusting the cell density to 1 × 105/mL for experimental research. The interferon concentration in five groups were 0, 5 × 105, 10 × 105, 50 × 105, 100 × 105 U/L, with different incubation time (0, 24, 72, 120 h), respectively. The cell growth status in different groups was observed in the inverted optical microscope; MTT was used to detect the inhibition of interferon on HEL cell proliferation. Cell apoptosis was detected by flow cytometry. Fluorescence quantitative PCR was used to detect the mutation gene of JAK2 V617F expression. Results Inhibition rates of Interferon on the HEL cell proliferation in 5 × 105 U/L, 10 × 105 U/L, 50 × 105 U/L, 100 × 105 U/L groups were 18.57%, 25.10%, 42.10%, 57.00%, respectively. JAK2 V617F/GAPDH by fluorescence quantitative was 1.556, 1.213, 0.870 respectively under the concentration of interferon 100 × 105 U/L for 24, 72, 120 h. Conclusions Interferon-α2b can inhibit HEL cells proliferation and induce HEL cells apoptosis. Increasing concentration of interferon increases HEL cell apoptosis rate. Interferon can inhibit JAK2 V617F expression of HEL cells in a dose-dependent manner.

Incidence of JAK2V617F mutation in myeloproliferative diseases and its clinical significance / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the incidence of JAK2V617F gene point mutation in patients with myeloproliferatives diseases (MPD) and its clinical significance.</p><p><b>METHODS</b>Genomic DNA from bone marrow and peripheral blood cells were extracted from 68 patients with MPD. Allele specific polymerase chain reaction was used to amplify the exon 12 of JAK2 gene which harbours V617F mutation. The PCR products were identified by DNA sequencing. JAK2V617F gene point mutation and its impact on peripheral blood cells were analyzed.</p><p><b>RESULTS</b>The incidence of JAK2V617F mutation in 68 patients with MPD was 65.28 %. The positive rate of JAK2V617F point mutation was 77.77 % in patients with PV (36/59), 56.52 % in patients with ET (23/59) and 44.44 % in patients with IMF (4/9). In all groups, the incidence of JAK2V617F point mutation in bone marrow and peripheral blood were equal. Patients with JAK2V617F mutation in PV group had higher counts of white blood cell and hemoglobin in peripheral blood than patients without JAK2V617F point mutation (P <0.05). Patients with JAK2V617F mutation in ET group had higher counts of white blood cell than those without JAK2V617F mutation (P <0.05); there was no significant difference in platelet count.</p><p><b>CONCLUSION</b>JAK2V617F point mutation can affect the hematologic features, which may be of diagnostic value for MDP with negative BCR-ABL gene.</p>

The influence of heparin on the apoptosis and proliferation for K562 cells induced by vincristine / 白血病·淋巴瘤

Objective To investigate the effect of heparin on the apoptosis and proliferation of human myeloid leukemia cell line K562 induced by vincristine.Methods K562 cells were pretreated by heparin for 1h,then cultured with 0.05 mg/L vincristine in 37℃ 5% CO2 for 24 h.Apoptosis of KS62 cells was evaluated by Hoechst 33342 staining,flow cytometer and DNA agarose gel electrophoresis after culture for 24 hours.The effect of heparin on KS62 cell proliferation and toxicitv was determined by Trypan blue staining and MTT assay.Results In the apeptosis induced group,the apeptosis rate was 40.10% dected by Hoechst 33342 fluorescence staining.The hepafin in different concentrations was found to be able to inhibit the apoptosis of K562 cells triggered by vincristine and the apoptosis rate was 32.47%,29.7%,25.5%,19.53% in the heparin groups of 25,50,100,200 U/ml,respectively.The apeptosis rate was significantly lower in the apeptosis induced group than in the heparin groups of 25,50,100,200 U/ml(P＜0.05).The typical DNA ladder could be found in the apoptosis-induced group,and the DNA ladder gradually disappeared along with the increase of heparin(5～200 U/ml).The sub-G1 peak of K562 cells could be found in the induced group by FACS and the apoptosis rate was 21.61%.In the heparin groups of 25,50,100,200 U/ml,the sub-G1 Peak of K562 cells gradually dropped and the apoptosis rate was 13.64%,11.75%,8.59%,6.03%(P＜0.05),respectively.After K562 cells were incubated with different hepafin concentrations(5～200 U/ml)for 24 hours,there was no difference compared with the normal control group in both the total live cell numbers and the cell proliferation rate measured by trypan blue staining and MTT assay(P＞0.05).Conclusion The results suggested that heparin had no influence on KS62 cell toxicity and proliferation,but may inhibit the apoptosis of KS62 cells induced by vincristine.