Expression of P53,P21 in Human Lung Adenocarcinoma A549 Cell Strains under Hypoxia Conditions and the Effect of TSA on Their Expression

This paper was designed to investigate the expression of p53, p21of A549 cell strains under hypoxic condition and the effect of trichostatin A (TSA), the inhibitor of histone deacetylase1 (HDAC1) on their expression. The authors designed 1 normoxia group (control group) and 6 hypoxia groups (experiemntal group): hypoxia 6 h group (A), TSA+ hypoxia 6 h (B), hypoxia 12 h group (C) ,hypoxia 24 h group (D), TSA+hypoxia 24 h (E), hypoxia 48 h group (F). The expression of HDAC1 in A549 cells was examined by using Western blot and the expression of p53, p21 in A549 cells and the effect of TSA on them were determined by using immunohistochemistry and reverse transcription polymerase chain reaction (RT PCR). The A value expressed by HDAC1 in A549 cell strains was 138±11 in the control group, 78±4, 86±5, 124±3, 120±9 in experimental groups A, C, D, F, respectively. The A value of the expression of the protein and mRNA of p53 in A549 cell strains were 0.12±0.02, 0.62±0.02 in the control group, 0.10±0.03, 0.32±0.03; 0.11±0.01, 0.33±0.02; 0.13±0.03, 0.58±0.01; 0.12±0.02, 0.56±0.02 in experimental group A, B, D, E, respectively. The A value of the expression of the protein and mRNA of p21 in A549 cell strains were 0.17±0.03, 0.62±0.03 in the control group, 0.16±0.02, 0.50±0.02; 0.14±0.02, 0.36±0.02; 0.15±0.03, 0.49±0.03; 0.13±0.02, 0.33±0.02 in experimental groups A, B, D, E, respectively. These results indicate that the expression of HDAC1 is regulated by hypoxia and the effect of TSA is closely related to the expression of P21 under hypoxia condition.

Effects of Trichostatin A on HDAC8 Expression,Proliferation and Cell Cycle of Molt-4 Cells

The effects of Trichostatin A （TSA） on histone deacetylase 8 （HDAC8） expression, proliferation and cell cycle arrest in T-lymphoblastic leukemia cell line Molt-4 cells in vitro were investigated. The effect of TSA on the growth of Molt-4 cells was studied by MTT assay. Flow cytometry was used to examine the cell cycle. The expression of HDAC8 was detected by using immunocytochemistry and Western blot. The results showed that proliferation of Molt-4 cells was inhibited in TSA-treated group in a time- and dose-dependent manner, The IC50 of TSA exposures for 24 h and 36 h were 254.3236 and 199.257 μg/L respectively. The cell cycle analysis revealed that Molt-4 was mostly in G0/G1 phase, and after treatment with TSA from 50 to 400 μg/L for 24 h, the percents of G0/G1 cells were decreased and cells were arrested in GJM phase. Treatment of TSA for 24 h could significantly inhibit the expression of HDAC8 protein in Molt-4 cells （P〈0.01）. It was concluded that TSA could decrease the expression of HDAC8 in Molt-4 cells, which contributed to the inhibition of proliferation and induction of cell cycle arrest in Molt-4 cells.