JBM  Vol.7 No.1 , January 2019
Trisubstituted Hexahydroimidazo[1,2-α]Pyridine 6 (TIP-6) as a Small-Molecule Inhibitor of Bcl-2 for Inhibition of Proliferation in Hepatoma Cells
Abstract: Background: Cancer poses a serious threat to human health and survival, and studies had been reported that imidazole or pyridine analogs play as an anti-cancer agent in cancer treatment. Meanwhile, Autophagy plays a dual and substantial role in maintaining cellular homeostasis in cancers, for it is either initiated to rescue cancer cells under stress or executed to promote autophagy cell death under certain circumstances. Objective: TIP-6 was designed and synthesized (7-(4-methoxyphenyl)-5,8α-diphenyl-1,2,3,7,8, 8α-hexahyd-roimidazo[1,2-α]pyridine-6) for evaluation of its biological effects on HepG2 cells and exploring the potential anti-cancer effect. Methods and Results: Chemical synthesis results indicated that the expected compound was obtained. The results of the MTT assay showed that TIP-6 arrested the growth of HepG2 cells in G2/M phase in the cell cycle, showing significant anti-proliferation effect. And analysis of morphological changes and formation of acidic vesicular organelles showed that the autophagy was induced but not apoptosis. The results were further validated by the enhanced expression of LC3I/II, Beclin1and down-regulated expression of Bcl-2in western blot analysis. In addition, the molecular docking predicted that TIP-6 preferentially binds to Bcl-2 and Bcl-xL in the active sites. Conclusion: Overall, this study demonstrated that autophagy cell death was executed in HepG2 cells which were induced by TIP-6.
Cite this paper: Zhang, W. , Pan, Y. , Zhou, H. , Gao, X. , Song, J. , Hua, Y. , Du, Y. , Yang, J. , Hui, X. , Wang, Q. (2019) Trisubstituted Hexahydroimidazo[1,2-α]Pyridine 6 (TIP-6) as a Small-Molecule Inhibitor of Bcl-2 for Inhibition of Proliferation in Hepatoma Cells. Journal of Biosciences and Medicines, 7, 29-41. doi: 10.4236/jbm.2019.71004.

[1]   Guo, J.Y., Xia, B. and White, E. (2013) Autophagy-Mediated Tumor Promotion. Cell, 155, 1216-1219.

[2]   Kroemer, G., Marino, G. and Levine, B. (2010) Autophagy and the Integrated Stress Response. Molecular Cell, 40, 280-293.

[3]   Wang, D.W., et al. (2015) The Different Roles of Selective Autophagic Protein Degradation in Mammalian Cells. Oncotarget, 6, 37098-37116.

[4]   Mizushima, N. and Levine, B. (2010) Autophagy in Mammalian Development and Differentiation. Nature Cell Biology, 12, 823-830.

[5]   Mizushima, N., et al. (2008) Autophagy Fights Disease through Cellular Self-Digestion. Nature, 451, 1069-1075.

[6]   Shintani, T. and Klionsky, D.J. (2004) Autophagy in Health and Disease: A Double-Edged Sword. Science, 306, 990-995.

[7]   Anding, A.L. and Baehrecke, E.H. (2015) Autophagy in Cell Life and Cell Death. Current Topics in Developmental Biology, 114, 67-91.

[8]   Altman, B.J. and Rathmell, J.C. (2009) Autophagy: Not Good OR Bad, But Good and Bad. Autophagy, 5, 569-570.

[9]   Bhutia, S.K., et al. (2013) Autophagy: Cancer’s Friend or Foe? Advances in Cancer Research, 118, 61-95.

[10]   Kimmelman, A.C. (2011) The Dynamic Nature of Autophagy in Cancer. Genes & Development, 25, 1999-2010.

[11]   Maycotte, P. and Thorburn, A. (2011) Autophagy and Cancer Therapy. Cancer Biology & Therapy, 11, 127-37.

[12]   Klionsky, D.J., et al. (2003) A Unified Nomenclature for Yeast Autophagy-Related Genes. Developmental Cell, 5, 539-545.

[13]   Maiuri, M.C., et al. (2009) Control of Autophagy by Oncogenes and Tumor Suppressor Genes. Cell Death and Differentiation, 16, 87-93.

[14]   Lee, J.S., et al. (2013) Anti-Cell Death Engineering of CHO Cells: Co-Overexpression of Bcl-2 for Apoptosis Inhibition, Beclin-1 for Autophagy Induction. Biotechnology and Bioengineering, 110, 2195-207.

[15]   Lindqvist, L.M., et al. (2014) Prosurvival Bcl-2 Family Members Affect Autophagy Only Indirectly, by Inhibiting Bax and Bak. Proceedings of the National Academy of Sciences of the United States of America, 111, 8512-8517.

[16]   Zhang, X.-Q., et al. (2010) Apogossypolone, a Novel Inhibitor of Antiapoptotic Bcl-2 Family Proteins, Induces Autophagy of PC-3 and LNCaP Prostate Cancer Cells in Vitro. Asian Journal of Andrology, 12, 697-708.

[17]   Gueiffier, A., Lhassan, M., et al. (1996) Synthesis of Acyclo-C-nucleosides in the Imidazo[1,2-a]pyridine and Pyrimidine Series as Antiviral Agents. Journal of Medical Chemistry, 39, 2856-2859.

[18]   Gueiffier, A., et al. (1998) Synthesis of Imidazo[1,2-a]pyridines as Antiviral Agents. Journal of Medical Chemistry, 41, 5108-5112.

[19]   Gudmundsson, K.S., et al. (1997) Synthesis and Antiviral Activity of Certain 5’-Modified Analogs of 2,5,6-Trichloro-1-(beta-D-ribofuranosyl)benzimidazole. Journal of Medical Chemistry, 40, 785-793.

[20]   Srivastava, P., Pandey, V.C., Misra, A.P., Gupta, P., Raj, K. and Bhaduri, A.P. (1998) Potential Inhibitors of Plasmodial Heme Oxygenase; an Innovative Approach for Combating Chloroquine Resistant Malaria. Bioorganic & Medicinal Chemistry, 6, 181-187.

[21]   Kaminski, J.J. and Doweyko, A.M. (1997) Antiulcer Agents. 6. Analysis of the in Vitro Biochemical and in Vivo Gastric Antisecretory Activity of Substituted Imidazo[1,2-a]pyridines and Related Analogues Using Comparative Molecular Field Analysis and Hypothetical Active Site Lattice Methodologies. Journal of Medical Chemistry, 40, 427-436.

[22]   Kaminski, J.J., et al. (1989) Antiulcer Agents. 4. Conformational Considerations and the Antiulcer Activity of Substituted Imidazo[1,2-a]pyridines and Related Analogues. Journal of Medical Chemistry, 32, 1686-1700.

[23]   Steyn, P.S. (1970) The Isolation, Structure and Absolute Configuration of Secalonic Acid D, the Toxic Metabolite of Penicillium oxalicum. Tetrahedron, 26, 51-57.

[24]   Hirano, A., Iwai, Y., Masuma, R., Tei, K. and Omura, S. (1979) Neoxaline, a New Alkaloid Produced by Aspergillus Japonicus. Production, Isolation and Properties. Journal of Antibiotics (Tokyo), 32, 781-785.

[25]   Koizumi, Y., Arai, M., Tomoda, H. and ōmura, S. (2004) Oxaline, a Fungal Alkaloid, Arrests the Cell Cycle in M Phase by Inhibition of Tubulin Polymerization. Biochimica et Biophysica Acta, 1693, 47-55.

[26]   Muchmore, S.W., et al. (1996) X-Ray and NMR Structure of Human BclxL, an Inhibitor of Programmed Cell Death. Nature, 381, 335-341.

[27]   Vance, B.A., Zacharchuk, C.M. and Segal, D.M. (1996) Recombinant Mouse Bcl-2(1-203). Two Domains Connected by a Long Protease-Sensitive Linker. Journal of Biological Chemistry, 271, 30811-30815.

[28]   Levine, B. and Kroemer, G. (2008) Autophagy in the Pathogenesis of Disease. Cell, 132, 27-42.

[29]   He, C. and Klionsky, D.J. (2009) Regulation Mechanisms and Signaling Pathways of Autophagy. Annual Review of Genetics, 43, 67-93.

[30]   Mizushima, N. (2004) Methods for Monitoring Autophagy. The International Journal of Biochemistry & Cell Biology, 36, 2491-2502.

[31]   Pattingre, S., et al. (2005) Bcl-2 Antiapoptotic Proteins Inhibit Beclin 1-Dependent Autophagy. Cell, 122, 927-939.

[32]   Oltersdorf, T., et al. (2005) An Inhibitor of Bcl-2 Family Proteins Induces Regression of Solid Tumours. Nature, 435, 677-681.