Li Wenjun, Cai Shaohui, Cai Lu, Li Xiaokun
School of Pharmacy, Wenzhou Medical College, Wenzhou, PR China.
Toxicol Lett. 2006 Aug 20;165(2):142-8. doi: 10.1016/j.toxlet.2006.02.006. Epub 2006 Apr 17.
Actinomycin D (ActD) is a well-known cytotoxic chemotherapeutic reagent and the prevention of ActD-induced apoptotic cell death has been an attractive issue for biomedical investigators. Since phosphatidylinositol-3 kinase (PI3K)/Akt pathway is essential for cell survival, the present study has examined whether the preventive effect of hepatocyte growth factor (HGF) on ActD-induced apoptotic cell death in a human hepatocyte-derived cell line (HL7702) is associated with PI3K/Akt activation. Apoptotic cell death was measured by several methods including Hoechst 33342 staining, DNA fragmentation, and flow cytometry. We found that ActD caused a significant increase in apoptotic cell death, an effect significantly prevented by pre-addition of HGF in the cultures. HGF was found to significantly activate Akt phosphorylation while pre-treatment with PI3K specific inhibitor wortmannin further enhanced ActD-induced apoptotic effect, and also significantly prevented HGF's protection against ActD-induced apoptosis. These results suggest that HGF's prevention of ActD-induced apoptotic cell death in HL7702 cells is associated with the activation of PI3K/Akt signaling.
放线菌素D（ActD）是一种著名的细胞毒性化疗试剂，预防ActD诱导的凋亡性细胞死亡一直是生物医学研究人员关注的热点问题。由于磷脂酰肌醇-3激酶（PI3K）/Akt信号通路对细胞存活至关重要，本研究探讨了肝细胞生长因子（HGF）对人肝细胞系（HL7702）中ActD诱导的凋亡性细胞死亡的预防作用是否与PI3K/Akt激活有关。通过多种方法检测凋亡性细胞死亡，包括Hoechst 33342染色、DNA片段化和流式细胞术。我们发现ActD导致凋亡性细胞死亡显著增加，而在培养物中预先添加HGF可显著预防这种效应。发现HGF可显著激活Akt磷酸化，而用PI3K特异性抑制剂渥曼青霉素预处理可进一步增强ActD诱导的凋亡效应，并且也显著阻止了HGF对ActD诱导凋亡的保护作用。这些结果表明，HGF预防HL7702细胞中ActD诱导的凋亡性细胞死亡与PI3K/Akt信号激活有关。
