Shu-Juan Jiang1, Song Zhang, Xiao-Yan Mu, Wei Li, Yan Wang. 1. Department of Respiratory Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China. shujuan-jiang@163.com
Abstract
OBJECTIVE: To investigate the effects of trichostatin A (TSA) and paclitaxel (PTX) on the apoptosis and microtubulin stabilization in human endometrial carcinoma cells and its mechanism. METHODS: Human endometrial carcinoma cells of the line Ark2, KLE and AN3 were cultured in the presence of TSA (TSA group), or PTX (PTX group), or TSA plus PTX (TSA + PTX group) respectively. The growth curve was obtained by trypan-blue exclusion assay. Apoptosis was observed by annexin V and Hoechst staining. Perturbation of mitochondrial membrane potential (MMP) was detected by flow cytometry. Western blotting was used to detect the protein expression of caspase-9, poly ADP-ribose polymerase (PARP), and acetylated microtubulin. RESULTS: The growth of the Ark2, KLE, and AN3 cells of the TSA, PTX, and TSA + PTX group, especially in the latter group, was inhibited. The Ark2 cell apoptotic rates 4 days later of the TSA, PTX, TSA + PTX, and control group were 4.25% +/- 0.25%, 12.12% +/- 0.62%, 16.56% +/- 0.74%, and 46.78% +/- 2.68% respectively by annexin V staining, and 3.39% +/- 0.12%, 6.00% +/- 0.25%, 10.05% +/- 0.53%, and 22.30% +/- 1.25% respectively by Hoechst staining. The apoptotic rates of the TSA + PTX group by both staining methods were both significantly higher than those of the other groups (all P < 0.05). Lysis of caspase-9 and PARP in the Ark2 and KLE cells increased greatly 24 hours after the TSA and PTX treatment. The disappearance rate of MMP in the Ark2 and AN3 cells of the TSA + PTX groups were 16.80% +/- 0.92% and 11.28% +/- 0.78% respectively, significantly higher than that of the PTX group (5.34% +/- 0.45% and 5.61% +/- 0.56% respectively) and TSA group (4.96% +/- 0.47% and 6.46% +/- 0.62% respectively, all P < 0.05). The expression of acetylated microtubulin was increased in the Ark2 and KLE cells of the TSA + PTX groups. CONCLUSIONS: Synergy of TSA and PTX inhibits the cell growth and induces apoptosis. The acetylation of non-histone protein induced by histone deacetylase inhibitor is one of the possible mechanisms of its anti-cancer effects.
OBJECTIVE: To investigate the effects of trichostatin A (TSA) and paclitaxel (PTX) on the apoptosis and microtubulin stabilization in humanendometrial carcinoma cells and its mechanism. METHODS:Humanendometrial carcinoma cells of the line Ark2, KLE and AN3 were cultured in the presence of TSA (TSA group), or PTX (PTX group), or TSA plus PTX (TSA + PTX group) respectively. The growth curve was obtained by trypan-blue exclusion assay. Apoptosis was observed by annexin V and Hoechst staining. Perturbation of mitochondrial membrane potential (MMP) was detected by flow cytometry. Western blotting was used to detect the protein expression of caspase-9, poly ADP-ribose polymerase (PARP), and acetylated microtubulin. RESULTS: The growth of the Ark2, KLE, and AN3 cells of the TSA, PTX, and TSA + PTX group, especially in the latter group, was inhibited. The Ark2 cell apoptotic rates 4 days later of the TSA, PTX, TSA + PTX, and control group were 4.25% +/- 0.25%, 12.12% +/- 0.62%, 16.56% +/- 0.74%, and 46.78% +/- 2.68% respectively by annexin V staining, and 3.39% +/- 0.12%, 6.00% +/- 0.25%, 10.05% +/- 0.53%, and 22.30% +/- 1.25% respectively by Hoechst staining. The apoptotic rates of the TSA + PTX group by both staining methods were both significantly higher than those of the other groups (all P < 0.05). Lysis of caspase-9 and PARP in the Ark2 and KLE cells increased greatly 24 hours after the TSA and PTX treatment. The disappearance rate of MMP in the Ark2 and AN3 cells of the TSA + PTX groups were 16.80% +/- 0.92% and 11.28% +/- 0.78% respectively, significantly higher than that of the PTX group (5.34% +/- 0.45% and 5.61% +/- 0.56% respectively) and TSA group (4.96% +/- 0.47% and 6.46% +/- 0.62% respectively, all P < 0.05). The expression of acetylated microtubulin was increased in the Ark2 and KLE cells of the TSA + PTX groups. CONCLUSIONS: Synergy of TSA and PTX inhibits the cell growth and induces apoptosis. The acetylation of non-histone protein induced by histone deacetylase inhibitor is one of the possible mechanisms of its anti-cancer effects.