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Article

The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization

  • Authors:
    • Tengfei Huang
    • Cuiping Li
    • Xingzhi Sun
    • Zhenfu Zhu
    • Yun Fu
    • Youxun Liu
    • Yanbin Yuan
    • Shaoshan Li
    • Changzheng Li
  • View Affiliations / Copyright

    Affiliations: Department of Molecular Biology and Biochemistry, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China, Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China, Department of Surgery, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
  • Pages: 1854-1862
    |
    Published online on: September 11, 2015
       https://doi.org/10.3892/ijo.2015.3158
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Abstract

Iron depletion and stimulation of iron-dependent free radical damage is a rapidly developing field for chelation therapy, but the iron mobilization from ferritin by chelators has received less attention. In this study, the di-2-pyridylketone 2-pyridine carboxylic acid hydrazone (DPPCAH) and its copper complex was prepared and characterized by NMR and MS spectra. The proliferation inhibition assay showed that both DPPCAH and its copper complex exhibited selectively proliferation inhibition for HepG2 (IC50, 4.6±0.2 µM for DPPACH and 1.3±0.2 µM for its copper complex), but less inhibition for HCT-116 cell line (IC50, >100 µM for DPPACH and 7.8±0.4 µM for its copper complex). The mechanistic studies revealed that DPPACH could remove iron from ferritin in a oxygen-catalytic manner, and contributed to redox activity of labile iron pool (LIP), that is less reported for the chelators that possess significant biological activity. The reactive oxygen species (ROS) generation and DNA cleavage assay in vitro and in vivo showed that both DPPACH-Fe(II) and DPPACH-Cu were redox-active species, indicating that ROS may mediate their antitumor activity. Further study revealed that both DPPACH and its copper complex displayed certain degree of inhibition of type II topoisomerase (Top) which contributed to their antitumor activity. Thus, the mechanism that iron mobilization by DPPACH from ferritin contributed to LIP was proposed, and both DPPACH and its copper complex were involved in ROS generation and Top II inhibition for their antitumor activities.
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View References

1 

Chen Z, Zhang D, Yue F, Zheng M, Kovacevic Z and Richardson DR: The iron chelators Dp44mT and DFO inhibit TGF-β-induced epithelial-mesenchymal transition via up-regulation of N-Myc downstream-regulated gene 1 (NDRG1). J Biol Chem. 287:17016–17028. 2012. View Article : Google Scholar : PubMed/NCBI

2 

Valko M, Rhodes CJ, Moncol J, Izakovic M and Mazur M: Free radicals, metals and antioxidants in oxidative stress-induced cancer. Chem Biol Interact. 160:1–40. 2006. View Article : Google Scholar : PubMed/NCBI

3 

Wondrak GT: Redox-directed cancer therapeutics: Molecular mechanisms and opportunities. Antioxid Redox Signal. 11:3013–3069. 2009. View Article : Google Scholar : PubMed/NCBI

4 

Crespo-Ortiz MP and Wei MQ: Antitumor activity of artemisinin and its derivatives: from a well-known antimalarial agent to a potential anticancer drug. J Biomed Biotechnol. 2012:2475972012. View Article : Google Scholar

5 

Wolszczak M and Gajda J: Iron release from ferritin induced by light and ionizing radiation. Res Chem Intermed. 36:549–563. 2010. View Article : Google Scholar

6 

Sánchez P, Gálvez N, Colacio E, Miñones E and Domínguez-Vera JM: Catechol releases iron(III) from ferritin by direct chelation without iron(II) production. Dalton Trans. 2005:811–813. 2005. View Article : Google Scholar

7 

Bou-Abdallah F, McNally J, Liu XX and Melman A: Oxygen catalyzed mobilization of iron from ferritin by iron(III) chelate ligands. Chem Commun (Camb). 47:731–733. 2011. View Article : Google Scholar

8 

Saad SY, Najjar TA and Al-Rikabi AC: The preventive role of deferoxamine against acute doxorubicin-induced cardiac, renal and hepatic toxicity in rats. Pharmacol Res. 43:211–218. 2001. View Article : Google Scholar : PubMed/NCBI

9 

Jansson PJ, Hawkins CL, Lovejoy DB and Richardson DR: The iron complex of Dp44mT is redox-active and induces hydroxyl radical formation: An EPR study. J Inorg Biochem. 104:1224–1228. 2010. View Article : Google Scholar : PubMed/NCBI

10 

Rao VA, Klein SR, Agama KK, Toyoda E, Adachi N, Pommier Y and Shacter EB: The iron chelator Dp44mT causes DNA damage and selective inhibition of topoisomerase IIalpha in breast cancer cells. Cancer Res. 69:948–957. 2009. View Article : Google Scholar : PubMed/NCBI

11 

Lovejoy DB, Jansson PJ, Brunk UT, Wong J, Ponka P and Richardson DR: Antitumor activity of metal-chelating compound Dp44mT is mediated by formation of a redox-active copper complex that accumulates in lysosomes. Cancer Res. 71:5871–5880. 2011. View Article : Google Scholar : PubMed/NCBI

12 

Fu Y, Zhou SF, Liu YX, Yang Y, Sun X and Li C: The cytotoxicity of benzaldehyde nitrogen mustard-2-pyridine carboxylic acid hydrazone being involved in topoisomerase IIa inhibition. Biomed Res Int. 2014:5270422014. View Article : Google Scholar

13 

Likussar W and Boltz DF: Theory of continuous variations plots and a new method for spectrophotometric determination of extraction and formation constants. Anal Chem. 43:1265–1272. 1971. View Article : Google Scholar

14 

Jakubowski W and Bartosz G: 2,7-dichlorofluorescin oxidation and reactive oxygen species: What does it measure? Cell Biol Int. 24:757–760. 2000. View Article : Google Scholar : PubMed/NCBI

15 

Singh NP, McCoy MT, Tice RR and Schneider EL: A simple technique for quantitation of low levels of DNA damage in individual cells. Exp Cell Res. 175:184–191. 1988. View Article : Google Scholar : PubMed/NCBI

16 

Osheroff N, Shelton ER and Brutlag DL: DNA topoisomerase II from Drosophila melanogaster. Relaxation of supercoiled DNA. J Biol Chem. 258:9536–9543. 1983.PubMed/NCBI

17 

Banerjee S, Sen S, Basak S, Mitra S, Hughes DL and Desplanches C: Two new pseudohalide-bridged Cu(II) complexes with a hydrazone ligand: Syntheses, crystal structures and magnetic studies. Inorg Chim Acta. 361:2707–2714. 2008. View Article : Google Scholar

18 

Ok K, Jung YW, Jee JG and Byun Y: Facile docking and scoring studies of carborane ligands with estrogen receptor. Bull Korean Chem Soc. 34:1051–1054. 2013. View Article : Google Scholar

19 

Trott O and Olson AJ: AutoDock Vina: Improving the speed and accuracy of docking with a new scoring function, efficient optimization, and multithreading. J Comput Chem. 31:455–461. 2010.

20 

Boukhalfa H and Crumbliss AL: Chemical aspects of siderophore mediated iron transport. Biometals. 15:325–339. 2002. View Article : Google Scholar : PubMed/NCBI

21 

Kakhlon O and Cabantchik ZI: The labile iron pool: Characterization, measurement, and participation in cellular processes(1). Free Radic Biol Med. 33:1037–1046. 2002. View Article : Google Scholar : PubMed/NCBI

22 

Stäubli A and Boelsterli UA: The labile iron pool in hepatocytes: Prooxidant-induced increase in free iron precedes oxidative cell injury. Am J Physiol. 274:G1031–G1037. 1998.PubMed/NCBI

23 

Becker EM, Lovejoy DB, Greer JM, Watts R and Richardson DR: Identification of the di-pyridyl ketone isonicotinoyl hydrazone (PKIH) analogues as potent iron chelators and anti-tumour agents. Br J Pharmacol. 138:819–830. 2003. View Article : Google Scholar : PubMed/NCBI

24 

Mylonas S and Mamalis A: Synthesis and antitumor activity of new thiosemicarbazones of 2-acetylimidazo[4,5-b]pyridine. J Heterocycl Chem. 42:1273–1281. 2005. View Article : Google Scholar

25 

Chaston TB, Watts RN, Yuan J and Richardson DR: Potent antitumor activity of novel iron chelators derived from di-2-pyridylketone isonicotinoyl hydrazone involves fenton-derived free radical generation. Clin Cancer Res. 10:7365–7374. 2004. View Article : Google Scholar : PubMed/NCBI

26 

Korystov YN, Shaposhnikova VV, Korystova AF and Emel'yanov MO: Detection of reactive oxygen species induced by radiation in cells using the dichlorofluorescein assay. Radiat Res. 168:226–232. 2007. View Article : Google Scholar : PubMed/NCBI

27 

Fatfat M, Merhi RA, Rahal O, Stoyanovsky DA, Zaki A, Haidar H, Kagan VE, Gali-Muhtasib H and Machaca K: Copper chelation selectively kills colon cancer cells through redox cycling and generation of reactive oxygen species. BMC Cancer. 14:5272014. View Article : Google Scholar : PubMed/NCBI

28 

Gaetke LM and Chow CK: Copper toxicity, oxidative stress, and antioxidant nutrients. Toxicology. 189:147–163. 2003. View Article : Google Scholar : PubMed/NCBI

29 

Jacquemin G, Margiotta D, Kasahara A, Bassoy EY, Walch M, Thiery J, Lieberman J and Martinvalet D: Granzyme B-induced mitochondrial ROS are required for apoptosis. Cell Death Differ. 22:862–874. 2015. View Article : Google Scholar

30 

Xiao D, Vogel V and Singh SV: Benzyl isothiocyanate-induced apoptosis in human breast cancer cells is initiated by reactive oxygen species and regulated by Bax and Bak. Mol Cancer Ther. 5:2931–2945. 2006. View Article : Google Scholar : PubMed/NCBI

31 

Pinar A, Yurdakul P, Yildiz I, Temiz-Arpaci O, Acan NL, Aki-Sener E and Yalcin I: Some fused heterocyclic compounds as eukaryotic topoisomerase II inhibitors. Biochem Biophys Res Commun. 317:670–674. 2004. View Article : Google Scholar : PubMed/NCBI

32 

Fu Y, Yang Y, Zhou S, Liu Y, Yuan Y, Li S and Li C: Ciprofloxacin containing Mannich base and its copper complex induce antitumor activity via different mechanism of action. Int J Oncol. 45:2092–2100. 2014.PubMed/NCBI

33 

Yalowich JC, Wu X, Zhang R, Kanagasabai R, Hornbaker M and Hasinoff BB: The anticancer thiosemicarbazones Dp44mT and triapine lack inhibitory effects as catalytic inhibitors or poisons of DNA topoisomerase IIα. Biochem Pharmacol. 84:52–58. 2012. View Article : Google Scholar : PubMed/NCBI

34 

Yang Y, Huang T, Zhou S, Fu Y, Liu Y, Yuan Y, Zhang Q, Li S and Li C: Antitumor activity of a 2-pyridinecarboxaldehyde 2-pyridinecarboxylic acid hydrazone copper complex and the related mechanism. Oncol Rep. 34:1311–1318. 2015.PubMed/NCBI

35 

Huang B: MetaPocket: A meta approach to improve protein ligand binding site prediction. OMICS. 13:325–330. 2009. View Article : Google Scholar : PubMed/NCBI

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Copy and paste a formatted citation
Spandidos Publications style
Huang T, Li C, Sun X, Zhu Z, Fu Y, Liu Y, Yuan Y, Li S and Li C: The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization. Int J Oncol 47: 1854-1862, 2015.
APA
Huang, T., Li, C., Sun, X., Zhu, Z., Fu, Y., Liu, Y. ... Li, C. (2015). The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization. International Journal of Oncology, 47, 1854-1862. https://doi.org/10.3892/ijo.2015.3158
MLA
Huang, T., Li, C., Sun, X., Zhu, Z., Fu, Y., Liu, Y., Yuan, Y., Li, S., Li, C."The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization". International Journal of Oncology 47.5 (2015): 1854-1862.
Chicago
Huang, T., Li, C., Sun, X., Zhu, Z., Fu, Y., Liu, Y., Yuan, Y., Li, S., Li, C."The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization". International Journal of Oncology 47, no. 5 (2015): 1854-1862. https://doi.org/10.3892/ijo.2015.3158
Copy and paste a formatted citation
x
Spandidos Publications style
Huang T, Li C, Sun X, Zhu Z, Fu Y, Liu Y, Yuan Y, Li S and Li C: The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization. Int J Oncol 47: 1854-1862, 2015.
APA
Huang, T., Li, C., Sun, X., Zhu, Z., Fu, Y., Liu, Y. ... Li, C. (2015). The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization. International Journal of Oncology, 47, 1854-1862. https://doi.org/10.3892/ijo.2015.3158
MLA
Huang, T., Li, C., Sun, X., Zhu, Z., Fu, Y., Liu, Y., Yuan, Y., Li, S., Li, C."The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization". International Journal of Oncology 47.5 (2015): 1854-1862.
Chicago
Huang, T., Li, C., Sun, X., Zhu, Z., Fu, Y., Liu, Y., Yuan, Y., Li, S., Li, C."The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization". International Journal of Oncology 47, no. 5 (2015): 1854-1862. https://doi.org/10.3892/ijo.2015.3158
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