Activated δ‑opioid receptors inhibit hydrogen peroxide‑induced apoptosis in liver cancer cells through the PKC/ERK signaling pathway

  • Authors:
    • Kaiqi Jia
    • Deguang Sun
    • Sunbin Ling
    • Yu Tian
    • Xuejun Yang
    • Jidong Sui
    • Bo Tang
    • Liming Wang
  • View Affiliations

  • Published online on: June 5, 2014     https://doi.org/10.3892/mmr.2014.2301
  • Pages: 839-847
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Abstract

Apoptotic liver cancer cells have important roles in liver tumorigenesis and liver cancer progression. Recent studies have shown that δ‑opioid receptors are highly expressed in human liver and liver cancer cells. The present study aimed to investigate the role of activated δ‑opioid receptors on human liver cancer cell apoptosis and its interrelation with the mitochondria and the protein kinase C/extracellular‑signal‑regulated kinase (PKC/ERK) signaling pathway. H2O2 was used to induce apoptosis in human liver cancer cells. During apoptosis, mitochondrial transmembrane potentials were observed to decrease, cytochrome c expression was found to increase and B cell lymphoma 2 (Bcl‑2) expression decreased. These findings suggested that H2O2‑induced apoptosis was mediated through the mitochondrial pathway. Of note, activated δ‑opioid receptors were observed to inhibit H2O2‑induced apoptosis in human liver cancer cells. Following δ‑opioid receptor activation, the number of apoptotic liver cancer cells decreased, mitochondrial transmembrane potentials were restored, cytoplasmic cytochrome c and Bcl‑2‑associated X protein expression decreased and Bcl‑2 expression increased. These data suggested that δ‑opioid receptor activation inhibited mitochondria‑mediated apoptosis. In addition, activation of δ‑opioid receptors was observed to increase the expression of PKC and ERK in human liver cancer cells. Furthermore, upon inhibition of the PKC/ERK signaling pathway, the protective effect associated with the δ‑opioid receptor on liver cancer cell apoptosis was inhibited, which was not associated with the status of δ‑opioid receptor activation. These findings suggested that the PKC/ERK signaling pathway has an important role in δ‑opioid receptor‑mediated inhibition of apoptosis in human liver cancer cells.
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August-2014
Volume 10 Issue 2

Print ISSN: 1791-2997
Online ISSN:1791-3004

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Spandidos Publications style
Jia K, Sun D, Ling S, Tian Y, Yang X, Sui J, Tang B and Wang L: Activated δ‑opioid receptors inhibit hydrogen peroxide‑induced apoptosis in liver cancer cells through the PKC/ERK signaling pathway. Mol Med Rep 10: 839-847, 2014.
APA
Jia, K., Sun, D., Ling, S., Tian, Y., Yang, X., Sui, J. ... Wang, L. (2014). Activated δ‑opioid receptors inhibit hydrogen peroxide‑induced apoptosis in liver cancer cells through the PKC/ERK signaling pathway. Molecular Medicine Reports, 10, 839-847. https://doi.org/10.3892/mmr.2014.2301
MLA
Jia, K., Sun, D., Ling, S., Tian, Y., Yang, X., Sui, J., Tang, B., Wang, L."Activated δ‑opioid receptors inhibit hydrogen peroxide‑induced apoptosis in liver cancer cells through the PKC/ERK signaling pathway". Molecular Medicine Reports 10.2 (2014): 839-847.
Chicago
Jia, K., Sun, D., Ling, S., Tian, Y., Yang, X., Sui, J., Tang, B., Wang, L."Activated δ‑opioid receptors inhibit hydrogen peroxide‑induced apoptosis in liver cancer cells through the PKC/ERK signaling pathway". Molecular Medicine Reports 10, no. 2 (2014): 839-847. https://doi.org/10.3892/mmr.2014.2301