Synthetic Dibenzoxanthene Derivatives Induce Apoptosis Through Mitochondrial Pathway in Human Hepatocellular Cancer Cells
A new series of dibenzoxanthenes 4a–4f were synthesized through the nucleophilic substitution and characterized by NMR and MS spectra. Their antitumor activity was screened by MTT assay. Compounds (except 4b and 4c) displayed strong growth inhibitory effects against chosen five tumor cells under light irradiation. The molecular mechanism of compound-induced cell apoptosis was investigated by AO/EB staining, comet assay, DCFH-DA, JC-1 fluorescent probe, and western blotting. Compounds induced the apoptosis of HepG2 cells and DNA damage. Location assay showed that compounds entered the nucleus of tumor cells. Furthermore, it was found that compounds induced loss of mitochondrial membrane potential, acceleration of ROS production, and activation of caspse-3, caspase-7, and caspase-9 proteins. Compounds upregulated the expression of pro-apoptotic Bim and Bax and downregulated the expression of anti-apoptotic Bcl-xl and Bcl-2. These results indicated that compounds induced the apoptosis of HepG2 cells through ROS-mediated mitochondrial pathway. The induction of apoptosis by dibenzoxanthenes may provide an important mechanism for their cancer chemopreventive function.
KeywordsDibenzoxanthenes Nucleophilic substitution Cytotoxicity Comet assay Apoptosis
This work was supported by the Priority Academic Program Development of Guangdong Higher Education Institutions (2013LYM0047), the Natural Science Foundation of Guangdong Province (No. 2016A030313728) and the National Nature Science Foundation of China (No. 81403111), and Project of Innovation for Enhancing Guangdong Pharmaceutical University, Provincial Experimental Teaching Demonstration Center of Chemistry & Chemical Engineering.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no competing interest.
- 2.Siegel, R., Ma, J., Zou, Z., & Jemal, A. (2014). Cancer statistics. CA: a Cancer Journal for Clinicians, 64(1), 9–29.Google Scholar
- 3.Gonzalez-Polo, R. A., Boya, P., Pauleau, A. L., Jalil, A., Larochette, N., Souquere, S., Eskelinen, E. L., Pierron, G., Saftig, P., & Kroemer, G. (2005). The apoptosis/autophagy paradox: autophagic vacuolization before apoptotic death. Journal of Cell Science, 118(14), 3091–3102.CrossRefPubMedGoogle Scholar
- 6.Li, X. K., Srinivasan, S. R., Connarn, J., Ahmad, A., Young, Z. T., Kabza, A. M., Zuiderweg, E. R. P., Sun, D. X., & Gestwicki, J. E. (2013). Analogues of the allosteric heat shock protein 70 (Hsp70) inhibitor, MKT-077, as anti-cancer agents. ACS Medicinal Chemistry Letters, 4, 1042−1047.PubMedCentralGoogle Scholar
- 7.Tuncbilek, M., Guven, E. B., Onder, T., & Atalay, R. C. (2012). Synthesis of novel 6-(4-substituted piperazine-1-yl)-9-(β-Dribofuranosyl) purine derivatives, which lead to senescence-induced cell death in liver cancer cells. Journal of Medicinal Chemistry, 55(7), 3058–3065.CrossRefPubMedGoogle Scholar
- 10.Hafez, H. N., Hegab, M. I., Ahmed-Farag, I. S., & El-Gazzar, A. B. A. (2008). A facile regioselective synthesis of novel spiro-thioxanthene and spiro-xanthene-90,2-[1,3,4]thiadiazole derivatives as potential analgesic and anti-inflammatory agents. Bioorganic & Medicinal Chemistry Letters, 18(16), 4538–4543.CrossRefGoogle Scholar
- 13.Yang, H. H., Han, B. J., Li, W., Liu, Y. J., & Wang, X. Z. (2015). Synthesis, molecular structure, DNA/protein binding, cytotoxicity, apoptosis, reactive oxygen species and mitochondrial membrane potential of dibenzoxanthenes derivatives. The Journal of Membrane Biology, 248(6), 951–965.CrossRefPubMedGoogle Scholar
- 21.Smiley, S. T., Reers, M., & Mottola-Hartshorn, C. (1991). Intracellular heterogeneity in mitochondrial membrane potentials revealed by a J-aggregate forming lipophilic cation JC-1. Proceedings of the National Academy of Sciences of the United States of America, 88(9), 3671–3675.CrossRefPubMedPubMedCentralGoogle Scholar
- 24.Spector, D. L., Goldman, R. D., & Leinwand, L. A. (1998). Cell: a laboratory manual (Vol. l). New York: Cold Spring Harbor Laboratory Press (Chapter 15).Google Scholar
- 26.Tarhan, L., Nakipoğlu, M., Kavakcıoğlu, B., Tongul, B., & Nalbantsoy, A. (2016). The induction of growth inhibition and apoptosis in HeLa and MCF-7 cells by Teucrium sandrasicum, having effective antioxidant properties. Applied Biochemistry and Biotechnology, 178(5), 1028–1041.CrossRefPubMedGoogle Scholar
- 27.Lan, A. T. Y., Wang, Y., & Chiu, J. F. (2008). Reactive oxygen species: current knowledge and applications in cancer research and therapeutic. Journal of Cellular Biochemistry, 104, 657−667.Google Scholar
- 28.Kuo, Y. F., Su, Y. Z., Tseng, Y. H., Wang, S. Y., Wang, H. M., & Chueh, P. J. (2010). Flavokawain B, a novel chalcone from Alpinia pricei Hayata with potent apoptotic activity: Involvement of ROS and GADD153 upstream of mitochondria- dependent apoptosis in HCT116 cells. Free Radical Biology & Medicine, 49, 214−226.CrossRefGoogle Scholar
- 30.Liu, J. Q., Mao, J., Jiang, Y., Xia, L. G., Liu, J. Q., Mao, J., Jiang, Y., & Xia, L. G. (2016). AGEs induce apoptosis in rat osteoblastcells by activating the caspase-3 signaling pathway under a high-glucose environment in vitro. Applied Biochemistry and Biotechnology, 178(5), 1015–1027.CrossRefPubMedGoogle Scholar
- 32.Song, W., Yang, H. B., Chen, P., Wang, S. M., Zhao, L. P., Xu, W. H., Fan, H. F., Gu, X., & Chen, L. Y. (2013). Apoptosis of human gastric carcinoma SGC-7901 induced by deoxycholic acid via the mitochondrial-dependent pathway. Applied Biochemistry and Biotechnology, 171(4), 1061–1071.CrossRefPubMedGoogle Scholar