Sinodielide A exerts thermosensitizing effects and induces apoptosis and G2/M cell cycle arrest in DU145 human prostate cancer cells via the Ras/Raf/MAPK and PI3K/Akt signaling pathways

  • Authors:
    • Masanori Hatashita
    • Masahiko Taniguchi
    • Kimiye Baba
    • Ken Koshiba
    • Takefumi Sato
    • Yutaka Jujo
    • Ryuta Suzuki
    • Sachiko Hayashi
  • View Affiliations

  • Published online on: November 27, 2013     https://doi.org/10.3892/ijmm.2013.1568
  • Pages: 406-414
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Abstract

Sinodielide A (SA) is a naturally occurring guaianolide, which is isolated from the root of Sinodielsia yunnanensis. This root, commonly found in Yunnan province, is used in traditional Chinese medicine as an antipyretic, analgesic and diaphoretic agent. A number of studies have reported that agents isolated from a species of Umbelliferae (Apiaceae) have antitumor activities. We previously reported, using combined treatments with this medicinal herb and hyperthermia at various temperatures, an enhanced cytotoxicity in the human prostate cancer androgen‑independent cell lines, PC3 and DU145, and analyzed the related mechanisms. In the present study, we investigated the effects of treatment with SA prior to hyperthermia on the thermosensitivity of DU145 cells, and the mechanisms related to the induction of apoptosis and G2/M cell cycle arrest via the activation of extracellular-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) signaling pathways, as well as the phosphoinositide 3-kinase (PI3K)/Akt signaling pathways. Cells were exposed to hyperthermia alone (40-44˚C) or hyperthermia in combination with SA. Lethal damage to cells treated with mild hyperthermia (40 or 42˚C) for up to 6 h was slight; however, hyperthermia in combination with SA synergistically enhanced thermosensivity. Lethal damage to cells treated with acute hyperthermia (43 or 44˚C) was more severe, but these effects were also enhanced and were more significant by the combined treatment with SA. The kinetics of apoptosis induction and cell cycle distribution were analyzed by flow cytometry. In addition, the levels of ERK1/2, JNK and Akt were determined by western blot analysis. The incidence of apoptotic cells after treatment with SA (20.0 µM) at 37˚C for 4 h, hyperthermia (44˚C) alone for 30 min, and the combination in sequence were examined. The sub-G1 division (%) in the diagram obtained by flow cytometry was applied to that assay. The percentage of apoptotic cells (10.53±5.02%) was higher at 48 h as compared to 0, 12 and 24 h after treatment. The distribution of DU145 cells in the G2/M cell cycle phase was markedly increased after 24 h of heating at 44˚C and after the combined treatment with heating and SA. The phosphorylation of ERK1/2 was reduced following treatment with heating and SA, while the levels of phosphorylated JNK (p-JNK) were markedly increased immediately after heating at 44˚C and when heating was combined with SA. By contrast, the levels of phosphorylated Akt (p-Akt) were immediately increased only after heating at 44˚C. Thus, we concluded that SA exerts its thermosensitizing effects on DU145 cells by inhibiting the activation of the MAPK/ERK1/2 and PI3K/Akt signaling pathways.
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2014-February
Volume 33 Issue 2

Print ISSN: 1107-3756
Online ISSN:1791-244X

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Spandidos Publications style
Hatashita M, Taniguchi M, Baba K, Koshiba K, Sato T, Jujo Y, Suzuki R and Hayashi S: Sinodielide A exerts thermosensitizing effects and induces apoptosis and G2/M cell cycle arrest in DU145 human prostate cancer cells via the Ras/Raf/MAPK and PI3K/Akt signaling pathways. Int J Mol Med 33: 406-414, 2014
APA
Hatashita, M., Taniguchi, M., Baba, K., Koshiba, K., Sato, T., Jujo, Y. ... Hayashi, S. (2014). Sinodielide A exerts thermosensitizing effects and induces apoptosis and G2/M cell cycle arrest in DU145 human prostate cancer cells via the Ras/Raf/MAPK and PI3K/Akt signaling pathways. International Journal of Molecular Medicine, 33, 406-414. https://doi.org/10.3892/ijmm.2013.1568
MLA
Hatashita, M., Taniguchi, M., Baba, K., Koshiba, K., Sato, T., Jujo, Y., Suzuki, R., Hayashi, S."Sinodielide A exerts thermosensitizing effects and induces apoptosis and G2/M cell cycle arrest in DU145 human prostate cancer cells via the Ras/Raf/MAPK and PI3K/Akt signaling pathways". International Journal of Molecular Medicine 33.2 (2014): 406-414.
Chicago
Hatashita, M., Taniguchi, M., Baba, K., Koshiba, K., Sato, T., Jujo, Y., Suzuki, R., Hayashi, S."Sinodielide A exerts thermosensitizing effects and induces apoptosis and G2/M cell cycle arrest in DU145 human prostate cancer cells via the Ras/Raf/MAPK and PI3K/Akt signaling pathways". International Journal of Molecular Medicine 33, no. 2 (2014): 406-414. https://doi.org/10.3892/ijmm.2013.1568