1.Effect of P38MAPK signal transduction pathway on apoptosis of THP-1 induced by allicin.
Yang LIAO ; Jianbin CHEN ; Weixue TANG ; Qunfang GE ; Qianwei LU ; Zesong YANG
China Journal of Chinese Materia Medica 2009;34(11):1439-1443
OBJECTIVEThe objective of this paper was to study the change of P38MAPK and Fas in the apoptosis of THP-1 cells induced by allicin.
METHODThe proliferation inhibition rates of THP-1 cells after various treatments were examined by MTT assay. Apoptosis rate was determined with Annexin V- FITC/PI double staining by flow cytometry. The expression and distribution change of the phosphorylation p38MAPK (P-p38MAPK) were detected by immunohistochemical staining. The changes of P-p38 MAPK and Fas proteins were detected by Western blot.
RESULTThe proliferations of leukemia cell line THP-1 are inhibited by allicin. MTT assay showed that allicin can inhibit the proliferation of the THP-1 cell, and the inhibition was dependent on both dose and time. The IC50 of 72 hours was 12.8 mg x L(-1). Apoptosis rate detected by Annexin V-FITC/PI was proportional to the concentration of the allicin. After the immunohistochemical staining test, the P-p38MAPK was located in the cell nucleus and plasma, showing deep brown, when adding allicin to THP-1 cell. Western blot test showed that the P-p38MAPK proteins expression was proportional to the concentration of Allicin and was also dose dependent. The levels of P-p38MAPK in negative control group, 1/2 IC50 of 72 hours group and IC50 of 72 hours group were 0.259 8 +/- 0.013 2, 0.61 2 +/- 0.008 3 and 0.505 6 +/- 0.005 5 respectively, and the levels of Fas proteins were 0.287 4 +/- 0.008 9, 0.426 8 +/- 0.007 9 and 0.597 1 +/- 0.010 9 respectively. The difference was statistically significant when compared with the negative control group (P < 0.01).
CONCLUSIONAllicin can significantly induce THP-1 cells apoptosis, and its mechanism may be related to the activation of P38MAPK/Fas.
Apoptosis ; drug effects ; Cell Line, Tumor ; Humans ; Neoplasms ; drug therapy ; metabolism ; physiopathology ; Phosphorylation ; Signal Transduction ; drug effects ; Sulfinic Acids ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism
2. An investigation of trichloroethylene-induced effects on histone methylation in L-02 hepatic cells
Rongxia DENG ; Xiaohu REN ; Jiawen RUAN ; Jian ZHENG ; Jiacheng ZHONG ; Weixue LU ; Xiaoqing ZOU ; Jianjun LIU
Chinese Journal of Preventive Medicine 2017;51(4):347-352
Objective:
To further explore TCE-induced hepatotoxicity and its mechanisms by identification of trichloroethylene (TCE) induced abnormal histone methylation in human liver cells.
Methods:
L-02 cells were treated with 0 and 8 mmol/L TCE for 24 h. Histones were extracted by acid. Liquid chromatography electrospray ionization tandem mass spectrometry (ESI-LC-MS/MS) were used to identify and quantify TCE related histone methylations. TCE induced abnormal methylation of H3K79 me2 and H3K79 me3 were validated by Western blot analysis. The further analysis of the function of histone abnormal methylation modifications were done by single cell gel electrophoresis (SCGE) and Western blot analysis of p53 and ɤH2AX.
Results:
After treatment with TCE for 24 h in L-02 cells, the 36 TCE related histone methylation sites in 28 peptide segments were identified by MS. After treatment with TCE in concentrations of 0 and 8.0 mmol/L in L-02 cells for 24 h, the relative expression level of histone H3K79 me3 were 1.00±0.06, 0.70±0.09 (
3. Studies on the DNA damage in the transformed bronchial epithelial cells induced by hexavalent chromium
Xiaohu REN ; Weixue LU ; Zhihong CHEN ; Wei LIU ; Shuqi WANG ; Nuanyuan LUO ; Jianjun LIU
Chinese Journal of Industrial Hygiene and Occupational Diseases 2018;36(7):481-484
Objective:
To investigate DNA damage in the transformed human bronchial epithelial cells (16HBE) induced by hexavalent chromium (Cr6+) and further elucidate the potential carcinogenesis mechanism of Cr6+.
Methods:
16HBE were treated with different concentration of Cr6+ (0, 0.625, 1.25, 2.5 μmol/L) for 15 weeks. The malignant degrees of transformed cells were identified by the assays for anchorage-independent growth and tumorigenicity. According to the single cell gel electrophoresis (SCGE) assay, the DNA damage rate was calculated. The expression level of 53BP1 was determined by Western blot.
Results:
Chromium-treated cells could form colonies in soft agar and tumors in nude mice. Compared with the control group, colony formation efficiency of 1.25μmol/L and 2.5 μmol/L Cr6+-treated cells in soft agar showed significant increases (p<0.05) . The 2.5 μmol/L Cr6+-treated cells also formed tumors subcutaneously in nude mice. Cr6+ could cause different degree of DNA damage to 16HBE cells in a dose-dependent manner. In addition, Western blot analyses showed that 53BP1 was aberrantly down-regulated at 2.5 μmol/L dose and has no significant changes at 0.625 μmol/L and 1.25 μmol/L dose under the treatment of Cr6+.
Conclusion
The declined expression of 53BP1 may mediate Cr6+-induced DNA damage and further involved in the cell malignant transformation.
4. Trichloroethylene-induced abnormal methylation on promoter region of SET in hepatic L-02 cells
Jiawen RUAN ; Zhihong CHEN ; Weixue LU ; Hang ZHANG ; Xiaohu REN ; Xinfeng HUANG ; Jianhui YUAN ; Yungang LIU ; Jianjun LIU
Chinese Journal of Industrial Hygiene and Occupational Diseases 2018;36(3):165-168
Objective:
To explore the trichloroethylene-induced alteration of methylation on the promoter region of SET and related mechanisms in hepatic L-02 cells.
Methods:
L-02 cells were treated with different concentrations of TCE(0 mmol/L, 1 mmol/L, 2 mmol/L, 4 mmol/L, 8 mmol/L) for 24 h. The genomic DNA were then extracted and modified by bisulfite sodium. The DNA methylation was then analyzed using bisulfite sequencing PCR (BSP).
Results:
The overall methylation on promoter region of SET was decreased along with the increased concentrations of TCE in hepatic L-02 cells. Moreover, 73 CpG islands were found abnormally altered, among which 9 were predicted in transcriptional factor binding regions.
Conclusion
The decreased levels of CpG islands in the transcriptional factor binding region may contribute to the elevation of SET in TCE-induced hepatotoxicity.