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目的研究肝癌细胞(HepG2)和正常胎肝细胞(CL-48)血管内皮生长因子(VEGF)和信号转导与转录激活因子3(STAT3)的表达状态,以及S-腺苷甲硫氨酸(SAM e)对其的干预作用,为HepG2和CL-48的不同调控途径提供功能性依据。方法在对数生长期的CL-48和HepG2细胞中加入不同浓度的SAM e(0、0.5、1.0 mmol/L)作用72 h,分别采用Northern印迹法、实时荧光定量PCR、W estern印迹法以及[3H]胸腺嘧啶脱氧核苷掺入法(3H-Tdr)和细胞克隆形成法,观察VEGF和STAT3表达的变化趋势,分析DNA合成及细胞生长能力的变化。结果SAM e作用前(SAM e 0 mmol/L),HepG2和CL-48均呈现VEGF和STAT3高表达状态。SAM e作用后:HepG2的VEGF和STAT3表达明显降低,并呈现剂量-效应关系,DNA合成和细胞生长能力明显受限;CL-48的STAT3表达虽然受到抑制,但VEGF的高表达状态无明显降低趋势,且DNA合成和细胞生长能力无显著变化。结论虽然HepG2和CL-48均呈现VEGF和STAT3的高表达,但二者具有不同的调控途径;SAM e通过抑制STAT3的组成性活化而降低VEGF的高表达状态,可能是SAM e的肝脏保护机制之一。
Objective To investigate the expression of vascular endothelial growth factor (VEGF) and signal transducers and activators of transcription 3 (STAT3) in HepG2 and normal fetal hepatocytes (CL-48), and to investigate the role of S-adenosylmethionine SAM e), which provided the functional basis for different regulatory pathways of HepG2 and CL-48. Methods Different concentrations of SAM e (0, 0.5 and 1.0 mmol / L) were added to CL-48 and HepG2 cells in logarithmic growth phase for 72 h. Northern blotting, real-time fluorescence quantitative PCR and Western blotting were used respectively. The [3H] thymidine incorporation (3H-Tdr) and cell clone formation method were used to observe the changes of VEGF and STAT3 expression. The changes of DNA synthesis and cell growth ability were analyzed. Results Before SAM e (SAM e 0 mmol / L), both HepG2 and CL-48 showed high expression of VEGF and STAT3. The expression of VEGF and STAT3 in HepG2 significantly decreased after treated with SAM e, showing a dose-effect relationship and obvious limitation of DNA synthesis and cell growth. Although the STAT3 expression of CL-48 was inhibited, the high expression of VEGF was not significantly reduced Trend, and DNA synthesis and cell growth ability did not change significantly. Conclusions Although both VEGF and STAT3 are highly expressed in both HepG2 and CL-48, SAMe may have different regulatory pathways. SAM e may reduce the high expression of VEGF by inhibiting the constitutive activation of STAT3, which may be the protective mechanism of SAM e one.