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Objective:To investigate the effects of arsenic trioxide combined with dihydroartemisinin on proliferation, cell cycle, and apoptosis of THP-1 cells, and explore the mechanism. Method:The thiazolyl blue （MTT） method was applied to detect the effect of different concentrations of arsenic trioxide, dihydroartemisinin and arsenic trioxide combined with dihydroartemisinin on the proliferation of THP-1 cells. Annexin V/propidium iodide（PI）assay was used to detect the change of THP-1 cell cycle and apoptosis．Western blot was performed to assess the expression of cysteine protease-3（Caspase-3）, cleaved Caspase-3, B-lymphocytoma-2（Bcl-2） and Bcl-2 associated X protein （Bax）. The changes of cell morphology were observed under high intension microscope. Result:Compared with blank group, arsenic trioxide and dihydroartemisinin both exhibited obvious antiproliferative effect on the human acute monocytic leukemia cell line THP-1 in time-dose dependence （P<0.01）. After 48 h, compared with the same dose of arsenic trioxide or that of dihydroartemisinin alone, the inhibition effect of 1 µmol·L-1 arsenic trioxide combined with 2 µmol·L-1 dihydroartemisinin on proliferation of THP-1 cells was significantly stronger （P<0.01）. Compared with the control group, arsenic trioxide combined with dihydroartemisinin significantly arrested the cells in G1 phase （P<0.01）, induced the downregulation of Caspase-3 and Bcl-2 （P<0.01） and upregulation of cleaved Caspase-3 significantly（P<0.05）. Conclusion:Arsenic trioxide combined with dihydroartemisinin can significantly inhibit the proliferation and induce apoptosis of THP-1 cells. The possible mechanism may be related to arrest the cells in G1 phase, reduce the expression of Caspase-3 and Bcl-2, increase the expression of cleaved Caspase-3.
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Aim To investigate the role of autophagy and its mechanism in Raji cell death induced by arse-nic trioxide. Methods Transmission electron micros-copy ( SEM) and MDC fluorescence staining were used to observe autophagy. MTT colorimetry was employed to assay the cellular proliferating activity. Cell apopto-sis and cell cycle analysis were performed using FITC-Annexin-V/PI double staining and flow cytometry ( FCM) . The expressions of LC3 and the conversion of LC3-I to LC3-II were measured by western bloting. The expression of bcl-2 mRNA and p53 mRNA were detected by reverse transcription-polymerase chain re-action ( RT-PCR ) . Results Arsenic trioxide could obviously inhibit the proliferation of Raji cells, arrest the cells at G2/M phase and induce apoptosis. Mean-while, arsenic trioxide markedly inhibited the expres-sion of bcl-2 mRNA and enhanced the expression of p53 mRNA in Raji cells. Arsenic trioxide also induced autophagy synchronously which paralleled with the in-duction of apoptosis in Raji cells, and 3-MA, an auto-phagy inhibitor, was able to reverse the arsenic triox-ide-activated autophagic activity, up-regulate bcl-2, down-regulated p53 expression and suppress the lethal effect of arsenic trioxide on Raji cells to reduce their sensitivity to arsenic trioxide. In contrast, the Rapamy-cin, an autophagy inducer, possessed the completely opposite effects on Raji cells compared with 3-MA. Conclusions The apoptosis and autophagic cell death are coexistent in arsenic trioxide-triggered death of Raji lymphoma cells, and Bcl-2 and p53 may play a key regulating role in this process.
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Objective To investigate the possibility of human gastric carcinoma cells apoptosis induced by arsenic trioxide and its mechanism.Methods After treatment with arsenic trioxide, the cytotoxicity to human gastric carcinoma cells MKN45 was quantified using trypan blue exclusion, and IC 50 was determined. Apoptotic cells were detected with flow cytometry, DNA cytofluorometry, DNA electrophoresis. Results Arsenic trioxide inhibited the growth of human gastric carcinoma cells MKN45 in a dose-dependent manner in a certain range of dose with a IC 50 of (11.05?0.25)?mol/L; Apoptotic peak, characteristic morphologic features of apoptosis and DNA ladder were observed in human gastric carcinoma cells MKN45 treated with 1~10 ?mol/L arsenic trioxide. Conclusions Arsenic trioxide can induce apoptosis of human gastric carcinoma cells MKN45, suggesting a great potential in the treatment of gastric carcinoma.
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@#ObjectiveTo detect the effect arsenic trioxide (As2O3) on the expressions of human gastric cancer genes nm23 and P53.MethodsThe expressions of proteins coded by nm23 and P53 were examined with immunohistochemistry method after treated by As2O3.ResultsThe expressions of proteins coded by nm23 and P53 decreased after treated by As2O3 (P<0.05).ConclusionAs2O3 can down-regulate the expressions of proteins coded by nm23 and P53.
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BACKGROUND: Recently, inorganic arsenic trioxide (As2O3) was reported to induce complete remission in a high proportion of patients with refractory acute promyelocytic leukemia (APL). To illustrate cellular and molecular mechanisms of As2O3 in the treatment of APL, many experimental studies were performed on APL-derived cell lines in vitro. Previous studies showed that As2O3 inhibited proliferation and induced apoptosis in the APL-derived cell lines. This study was done to clarify the in vitro mechanisms of As2O3-induced apoptosis in APL-derived NB4 cell lines. METHODS: To determine the effects of As2O3 in the various concentrations, NB4 cells were cultured with 0.1 to 2micro M/L of As2O3. To assay the apoptosis in NB4 cell lines, DNA fragmentation assay and TUNEL were performed. To find out the molecular change of As2O3- induced apoptotic NB4 cell lines, RT-PCR and Western blot analysis for PML-RARalpha chimeric protein expression and flow cytometry for bcl- 2/bax expression were performed. To clarify the caspase activation pathway, Western blot analysis and flow cytometry for procaspase expression were performed. RESULTS: As2O3 induces apoptosis on NB4 cells in relatively high concentration (0.5 to 2 micro M/L) for 2 days. After 2 days of culture the PML-RARalpha chimeric protein expression decreased rapidly by Western blot and RT-PCR analysis and bcl-2 expression also decreased by flow cytometry. The expression of bax by flow cytometry showed a marked increase in high concentration (2micro M/L) but there was no change in low concentration (0.5micro M/L). In the Western blot analysis, the amount of pro`enzyme of caspase-3 was significantly decreased in the cells with high concentration (2micro M/L) compared with that in the cells with low concentration (0.5micro M/L). As2O3 induces proteolytic processing of pro-caspase 7 but not pro-caspase 9 and 8. CONCLUSION: Apoptosis of APL-derived NB4 cell lines was induced by As2O3 and progressed rapidly in higher concentrations. During apoptosis, activation of caspase-7 pathway and degradation of PML-RARalpha chimeric protein, decrease in bcl-2 and increase in bax were shown.
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Humans , Apoptosis , Arsenic , Blotting, Western , Caspase 3 , Caspase 7 , Cell Line , DNA Fragmentation , Flow Cytometry , In Situ Nick-End Labeling , Leukemia, Promyelocytic, AcuteABSTRACT
OBJECTIVE:To detect the expressions of five gastric cancer cell metastasis associated genes induced by arsenic trioxide METHODS:The expressions of CD44,P53,nm23,H-ras,PCNA induced by arsenic trioxide were examined by immunohistochemistry method RESULTS:Arsenic trioxide induced the decrease of the expressions of CD44,P53,PCNA in gastric cancer cells;the expressions of nm23 and H-ras were not changed by As2 O 3 CONCLUSION:It is tentatively proved that the antineoplastic action of As2 O 3 may be related to the down-regulation of CD44,P53 and PCNA
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Objective To test the expression of five cancer metastasis associated genes indu ced by arsenic trioxide. Methods The expression of CD44,p53,nm23 ,H-r as and PCNA induced by arsenic trioxide were examined by immunohistochemistry me thod . Results Arsenic trioxide induced decrease of the expression of C D44,p 53 and PCNA in gastric cancer cells,and the expression of nm23 and H-ras were not changed by As_2O_3. Conclusions Arsenic trioxide inhibits the metastasis of gastric ca ncer cells through reducing the expression of cancer metastasis associated gene s.
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Objective To observe the effects of arsenic trioxide(As2O3)on the expressions of TNF-?,Fas and bcl-2 in lung adenocarcinoma cells(LAC)and to explore the mechanism of arsenic trioxide inducing apoptosis.Methods The expressions of TNF-?,Fas and bcl-2 in lung adenocarcinoma cells pretreated by arsenious acid were determined by the double antibody sandwich ABC-ELISA method.Results Compared with the control group,As2O3 showed no effects on the contents of bcl-2 in lung adenocarcinoma cells after 72 hours treatment,but increased the contents of TNF-? and Fas significantly,and the effects in different concentration groups had significant differences.The protein expressions of TNF-? and Fas showed a tendency of concentration-dependent increasing.Conclusions The results suggest that As2O3 induces the apoptosis of LAC cells possibly by up-regulating the expression of TNF-? and Fas.
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Objective To investigate the biological effects of As 2O 3 and its mechanism on human oral squamous carcinoma cell line in vitro . Methods The effects of As 2O 3 on Tca8113 cell line were investigated in vitro with morphological method, MTT, clone forming, DNA ladder, TUNEL assay and flow cytometry(FCM). Results As 2O 3 had marked suppressive effect on the growth of Tca8113 cell line. The growth suppression rate of the Tca8113 cells was 76.3% shown by MTT. DNA ladder, TUNEL and FCM showed As 2O 3 could induce the apoptosis of Tca8113 which might be related to cell cycle arrest shown by FCM. Conclusion As 2O 3 can inhibit the growth and induce the apoptosis of oral squamous carcinoma cell in vitro .