|The promoting molecular mechanism of alpha-fetoprotein on the growth of human hepatoma Bel7402 cell line|
|Li, MS1; Li, PF1; He, SP1; Du, GG1; Li, G1|
|刊名||WORLD JOURNAL OF GASTROENTEROLOGY|
|WOS标题词||Science & Technology|
|类目[WOS]||Gastroenterology & Hepatology|
|研究领域[WOS]||Gastroenterology & Hepatology|
|关键词[WOS]||HUMAN HEPATOCELLULAR-CARCINOMA ; GENE-EXPRESSION ; FETAL HEPATOCYTES ; BINDING-PROTEINS ; DOWN-REGULATION ; MESSENGER-RNA ; TUMOR-CELLS ; IN-VITRO ; PROLIFERATION ; ACID|
AIM: The goal of this study was to characterize the AFP receptor, its possible signal transduction pathway and its proliferative functions in human hepatoma cell line Bel 7402.
METHODS: Cell proliferation enhanced by AFP was detected by MTT assay, H-3-thymidine incorporation and S-stage percentage of cell cycle analysis. With radioactive labeled I-125-AFP for receptor binding assay; cAMP accumulation, protein kinase A activity were detected by radioactive immunosorbent assay and the change of intracellular free calcium ([ Ca2+](i)) was monitored by scanning fluorescence intensity under TCS-NT confocal microscope. The expression of oncogenes N- ras, p53, and p21(ras) in the cultured cells in vitro were detected by Northern blotting and Western blotting respectively.
RESULTS: It was demonstrated that AFP enhanced the proliferation of human hepatoma Bel 7402 cell in a dose dependent fashion as shown in MTT assay, H-3-thymidine incorporation and S-phase percentage up to 2-fold. Two subtypes of AFP receptors were identified in the cells with Kds of 1.3 x 10(-9) mol.L-1 and 9.9 x 10(-8) mol.L-1 respectively. Pretreatment of cells with AFP resulted. in a significant increase (625 %) in cAMP accumulation. The activity of protein kinase A activity were increased up to 37.5, 122.6, 73.7 and 61. 2 % at treatment time point 2, 6, 12 and 24 hours, The level of intracellular calcium were elevated after the treatment of alpha-fetoprotein and achieved to 204 % at 4 min, The results also showed that AFP (20 mg.L-1) could upregulate the expression of N-m oncogenes and p53 and p21(ras) in Bel 7402 cells. In the later case, the alteration were 81. 1 % (12 h) and 97.3 % (12 h) respectively compared with control.
CONCLUSION: These results demonstrate that AFP is potential growth factor to promote the proliferation of human hepatoma Bel 7402 cells. Its growth-regulatory effects are mediated by its specific plasma membrane receptors coupled with its transmembrane signaling transduction through the pathway of cAMP-PKA and intracellular calcium to regulate the expression of oncogenes.
|作者单位||1.Hainan Med coll, Dept Biochem, Haikou 571101, Hainan, Peoples R China|
2.Peking Univ, Dept Biochem & Mol Biol, Hlth Sci Ctr, Beijing 100083, Peoples R China
3.Peking Univ, Dept Biophys, Hlth Sci Ctr, Beijing 100083, Peoples R China
|Li, MS,Li, PF,He, SP,et al. The promoting molecular mechanism of alpha-fetoprotein on the growth of human hepatoma Bel7402 cell line[J]. WORLD JOURNAL OF GASTROENTEROLOGY,2002,8(3):469-475.|
|APA||Li, MS,Li, PF,He, SP,Du, GG,&Li, G.(2002).The promoting molecular mechanism of alpha-fetoprotein on the growth of human hepatoma Bel7402 cell line.WORLD JOURNAL OF GASTROENTEROLOGY,8(3),469-475.|
|MLA||Li, MS,et al."The promoting molecular mechanism of alpha-fetoprotein on the growth of human hepatoma Bel7402 cell line".WORLD JOURNAL OF GASTROENTEROLOGY 8.3(2002):469-475.|