Effect Of Arsenic Trioxide On The Expression Of PML Isoforms And HTERT Of Cutaneous T Cell Lymphoma Cell Line Hut-78 Cells

Objective:To investigate the possible function and mechanism of the genes, such as Promyelocytic Leukemia, Promyelocytic Leukemia isoform I, Promyelocytic Leukemia isoformⅣ, Promyelocytic Leukemia isoform V and human telomerase reverse transcriptase, in Arsenic Trioxide on cutaneous T cell lymphoma cell line Hut-78 cells by detecting the apoptosis, effects of cell cycles and expression of these genes in cutaneous T-cell lymphoma cell line Hut-78 which was treated with Arsenic Trioxide of different concentrations.Methods:The effect of Arsenic Trioxide in different concentrations and for different duration of time on apoptosis and cell cycles of hut-78 cells were analyzed by Flow cytometry with PI staining. The transcription level changes of hTERT, PML, PML-I, PML-Ⅳand PML-Ⅴgenes were detected by the reverse transcriptase-polymerase chain reaction (RT-PCR)Results:1. Hut-78 cells were treated with the concentration range of 2-10μmol/L of ATO respectively for 24 h,48h and 72h. Then cell cycle, apoptosis and necrosis were measured by flow cytometry with PI staining. The results showed that, the ratio of G2/M phase of Hut-78 cells that was treated with Arsenic Trioxide was increased. When the Hut-78 cells were treated with 10μmol/L Arsenic Trioxide for 72 hours, the highest percentage of G2/M phase was detected. With the increasing of concentration and extending of action time, the rate of apoptosis and necrosis of Hut-78 cells was gradually increased; 2.The expressions of hTERT, PML, PML-Ⅰ, PML-Ⅳand PML-Ⅴgenes in Hut-78 cells treated with Arsenic Trioxide in different concentrations for different action time were detected by RT-PCR.The results show that:(1) The expression of hTERT mRNA gradually decreased with the concentration of ATO increasing and acting time extending; (2) After treated with ATO in different concentrations after 48h, the transcription level of PML reached a maximum value, which was gradually decreased from 48h to 72h; (3) With prolonging treatment with 2umol/L and 10umol/L ATO respectively,the transcription level of PML-Ⅰwas gradually increased,When the concentration of ATO is 0 umol/L and 5 umol/L respectively,with prolonging treatment,the transcription level was gradually decreased from 24h to 48h,while that was gradually increased from 48h to 72h; (4) With ATO in different concentration,the transcription level of PML-Ⅳwas gradually increased from 24h to 48h with the acting time extending,while that was gradually decreased from 48h to 72h; (5) When the concentration of ATO is 0 umol/L and 2 umol/L respectively,with prolonging treatment,The expression of PML-Ⅴdid not change significantly.When the concentration of ATO was 5 umol/L and 10 umol/L respectively, with prolonging treatment, the transcription level was gradually increased; And at the dosage of 10 umol/L the increased trend of the transcription level was the most significant; 3. There was no correlation between the expression level of PML-IVand hTERT.Conclusion:1.Arsenic trioxide can inhibit the proliferation of Hut-78 cells in a certain range of concentrations, which may be related to the decreasement in the transcription level of hTERT to some extent; 2.ATO can induce apoptosis of Hut-78 cells. And apoptosis occurs mainly in G2/M phase, which may be related to PML, PML-Ⅰand PML-Ⅳincreased and decreased the expression of telomerase activity; 3.ATO can induce apoptosis of Hut-78 cells, which is dependent on time and dose; 4.The expression of PML-Ⅴwas different with ATO in different concentrations, we speculated that the expression level of PML-Ⅴcould remarkably increase only in the strong stress caused by drug.