Article

Enhanced antitumor effect of combined triptolide and ionizing radiation.

Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York 14642-8647, USA.
Clinical Cancer Research (Impact Factor: 7.84). 09/2007; 13(16):4891-9. DOI: 10.1158/1078-0432.CCR-07-0416
Source: PubMed

ABSTRACT The lack of effective treatment for pancreatic cancer results in a very low survival rate. This study explores the enhancement of the therapeutic effect on human pancreatic cancer via the combination of triptolide and ionizing radiation (IR).
In vitro AsPC-1 human pancreatic cancer cells were treated with triptolide alone, IR alone, or triptolide plus IR. Cell proliferation was analyzed with sulforhodamine B (SRB) method and clonogenic survival; comparison of apoptosis induced by the above treatment was analyzed by annexin V-propidium iodide (PI) staining. Furthermore, the expression of apoptotic pathway intermediates was measured by the assay of caspase activity and Western blot. Mitochondrial transmembrane potential was determined by JC-1 assay. In vivo, AsPC-1 xenografts were treated with 0.25 mg/kg triptolide, 10 Gy IR, or triptolide plus IR. The tumors were measured for volume and weight at the end of the experiment. Tumor tissues were tested for terminal nucleotidyl transferase-mediated nick end labeling (TUNEL) and immunohistochemistry.
The combination of triptolide plus IR reduced cell survival to 21% and enhanced apoptosis, compared with single treatment. In vivo, tumor growth of AsPC-1 xenografts was reduced further in the group treated with triptolide plus IR compared with single treatment. TUNEL and immunohistochemistry of caspase-3 cleavage in tumor tissues indicated that the combination of triptolide plus IR resulted in significantly enhanced apoptosis compared with single treatments.
Triptolide in combination with ionizing radiation produced synergistic antitumor effects on pancreatic cancer both in vitro and in vivo and seems promising in the combined modality therapy of pancreatic cancer.

0 Bookmarks
 · 
74 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Triptolide, an active compound extracted from Chinese herb Leigongteng (Tripterygium wilfordii Hook F.), shows a broad-spectrum of anticancer activity through its cytotoxicity. However, the efficacy of triptolide on laryngocarcinoma rarely been evaluated, and the mechanism by which triptolide-induced cellular apoptosis is still not well understood. In this study, we found that triptolide significantly inhibited the laryngocarcinoma HEp-2 cells proliferation, migration and survivability. Triptolide induces HEp-2 cell cycle arrest at the G1 phase and apoptosis through intrinsic and extrinsic pathways since both caspase-8 and -9 are activated. Moreover, triptolide enhances p53 expression by increasing its stability via down-regulation of E6 and E6AP. Increased p53 transactivates down-stream target genes to initiate apoptosis. In addition, we found that short time treatment with triptolide induced DNA damage, which was consistent with the increase in p53. Furthermore, the cytotoxicity of triptolide is decreased by p53 knockdown or use of caspases inhibitor. In conclusion, our results demonstrated that triptolide inhibits cell proliferation and induces apoptosis in laryngocarcinoma cells by enhancing p53 expression and activating p53 functions through induction of DNA damage and suppression of E6 mediated p53 degradation. These studies indicate that triptolide is a potential anti-laryngocarcinoma drug.
    PLoS ONE 01/2013; 8(11):e80784. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Triptolide (TPL/TL) is a natural drug with novel anticancer effects. Preclinical studies indicated that TPL inhibits cell proliferation, induces cell apoptosis, inhibits tumor metastasis and enhances the effect of other therapeutic methods in various cancer cell lines. Multiple molecules and signaling pathways, such as caspases, heat-shock proteins, NF-κB, and deoxyribonucleic acid (DNA) repair-associated factors, are associated with the anti-cancer effect. TPL also improves chemoradiosensitivity in cancer therapy. Phase I trials indicate the potential clinical value of TPL use. However, further trials with larger sample sizes are needed to confirm these results.
    10/2014; 26(5):622-6.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Most bone-related diseases are characterized by excessive bone resorption by osteoclasts. Receptor activator of nuclear factor-kappaB (NF-κB) ligand (RANKL) has emerged as a major mediator of bone resorption, commonly associated with cancer and chronic inflammatory diseases. Thus inhibitors of RANKL signaling have a potential in preventing bone loss. In the present study, we investigated the ability of triptolide, a diterpenoid isolated from Thunder of God Vine, to inhibit signaling by receptor activator of NF-κB (RANK) and its ligand (RANKL) and to modulate osteoclastogenesis induced by RANKL and human cancer cells. We found that triptolide suppressed RANKL-induced differentiation of precursor cells to osteoclasts, and also inhibited osteoclast formation induced by human breast tumor cells (MDA-MB-231), multiple myeloma cells (U266) and prostate tumor cells (PC-3). Triptolide inhibited RANKL-induced NF-κB activation in osteoclast precursor cells by inhibiting IκBα kinase activation, IκBα phosphorylation, and IκBα degradation. Our results suggest that triptolide effectively inhibits RANKL-induced NF-κB activation and RANKL- and tumor cell-induced osteoclastogenesis. This warrants further study of triptolide as a potential therapy for osteoporosis and cancer-associated bone loss.
    Biochimie 10/2014; · 3.14 Impact Factor