Combination of chloroquine and GX15-070 (obatoclax) results in synergistic cytotoxicity against pancreatic cancer cells

Wang,Guan; Chen,Shaohua; Edwards,Holly; Cui,Xinming; Cui,Li; Ge,Yubin

doi:10.3892/or.2014.3525

Combination of chloroquine and GX15-070 (obatoclax) results in synergistic cytotoxicity against pancreatic cancer cells

Authors:
- Guan Wang
- Shaohua Chen
- Holly Edwards
- Xinming Cui
- Li Cui
- Yubin Ge
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Affiliations: National Engineering Laboratory of AIDS Vaccine, Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun, P.R. China, Department of Oncology, Wayne State University School of Medicine, Detroit, MI, USA, Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, P.R. China
Published online on: October 3, 2014 https://doi.org/10.3892/or.2014.3525
Pages: 2789-2794

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Abstract

Pancreatic cancer is an aggressive disease with a poor prognosis. Therefore, new treatment is urgently required. GX15-070 is a pan-Bcl-2 inhibitor which has shown promising antitumor activity in different malignancies. We previously demonstrated that clinically achievable concentrations of GX15-070 caused growth arrest in pancreatic cancer cell lines. However, they only induced minimal levels of apoptosis. We hypothesized that GX15-070 induced autophagy in pancreatic cancer cells which blocked apoptosis. In this study, we investigated the effects of GX15-070 on autophagy and the antitumor activities of the combination of GX15-070 and chloroquine (CQ), an autophagy inhibitor, in six pancreatic cancer cell lines. We found that GX15-070 treatment indeed induced autophagy in 5 of the 6 pancreatic cancer cell lines, reflected by the conversion of LC3B-I to LC3B-II and detection of autophagosomes by transmission electron microscopy. Furthermore, we found additive to synergistic antitumor interactions in all six cell lines by MTT assays. CQ significantly enhanced GX15-070-induced apoptosis in the cell line models, possibly due to downregulation of Bcl-2, Bcl-xL and Mcl-1 in the cells by the two agents. These results provide compelling evidence for the further development of the combination of GX15-070 and CQ in pancreatic cancer.

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1	Siegel R, Ma J, Zou Z and Jemal A: Cancer statistics, 2014. CA Cancer J Clin. 64:9–29. 2014. View Article : Google Scholar
2	Vincent A, Herman J, Schulick R, Hruban RH and Goggins M: Pancreatic cancer. Lancet. 378:607–620. 2011. View Article : Google Scholar
3	Miyamoto Y, Hosotani R, Wada M, et al: Immunohistochemical analysis of Bcl-2, Bax, Bcl-X, and Mcl-1 expression in pancreatic cancers. Oncology. 56:73–82. 1999. View Article : Google Scholar : PubMed/NCBI
4	Wei Y, Kadia T, Tong W, et al: The combination of a histone deacetylase inhibitor with the Bcl-2 homology domain-3 mimetic GX15-070 has synergistic antileukemia activity by activating both apoptosis and autophagy. Clin Cancer Res. 16:3923–3932. 2010. View Article : Google Scholar
5	McCoy F, Hurwitz J, McTavish N, et al: Obatoclax induces Atg7-dependent autophagy independent of beclin-1 and BAX/BAK. Cell Death Dis. 1:e1082010. View Article : Google Scholar : PubMed/NCBI
6	Konopleva M, Watt J, Contractor R, et al: Mechanisms of anti-leukemic activity of the novel Bcl-2 homology domain-3 mimetic GX15-070 (obatoclax). Cancer Res. 68:3413–3420. 2008. View Article : Google Scholar : PubMed/NCBI
7	Nguyen M, Marcellus RC, Roulston A, et al: Small molecule obatoclax (GX15-070) antagonizes MCL-1 and overcomes MCL-1-mediated resistance to apoptosis. Proc Natl Acad Sci USA. 104:19512–19517. 2007. View Article : Google Scholar : PubMed/NCBI
8	Rahmani M, Aust MM, Attkisson E, Williams DC Jr, Ferreira-Gonzalez A and Grant S: Inhibition of Bcl-2 antiapoptotic members by obatoclax potently enhances sorafenib-induced apoptosis in human myeloid leukemia cells through a Bim-dependent process. Blood. 119:6089–6098. 2012. View Article : Google Scholar
9	Chen S, Wang G, Niu X, et al: Combination of AZD2281 (Olaparib) and GX15-070 (Obatoclax) results in synergistic antitumor activities in preclinical models of pancreatic cancer. Cancer Lett. 348:20–28. 2014. View Article : Google Scholar : PubMed/NCBI
10	Maiuri MC, Zalckvar E, Kimchi A and Kroemer G: Self-eating and self-killing: crosstalk between autophagy and apoptosis. Nat Rev Mol Cell Biol. 8:741–752. 2007. View Article : Google Scholar : PubMed/NCBI
11	Yang Z and Klionsky DJ: Mammalian autophagy: core molecular machinery and signaling regulation. Curr Opin Cell Biol. 22:124–131. 2010. View Article : Google Scholar : PubMed/NCBI
12	Malik SA, Orhon I, Morselli E, et al: BH3 mimetics activate multiple pro-autophagic pathways. Oncogene. 30:3918–3929. 2011. View Article : Google Scholar : PubMed/NCBI
13	Pan J, Cheng C, Verstovsek S, Chen Q, Jin Y and Cao Q: The BH3-mimetic GX15-070 induces autophagy, potentiates the cytotoxicity of carboplatin and 5-fluorouracil in esophageal carcinoma cells. Cancer Lett. 293:167–174. 2010. View Article : Google Scholar : PubMed/NCBI
14	Vogler M, Weber K, Dinsdale D, et al: Different forms of cell death induced by putative BCL2 inhibitors. Cell Death Differ. 16:1030–1039. 2009. View Article : Google Scholar : PubMed/NCBI
15	Maiuri MC, Criollo A, Tasdemir E, et al: BH3-only proteins and BH3 mimetics induce autophagy by competitively disrupting the interaction between Beclin 1 and Bcl-2/Bcl-X(L). Autophagy. 3:374–376. 2007. View Article : Google Scholar
16	Hashimoto D, Blauer M, Hirota M, Ikonen NH, Sand J and Laukkarinen J: Autophagy is needed for the growth of pancreatic adenocarcinoma and has a cytoprotective effect against anti-cancer drugs. Eur J Cancer. 50:1382–1390. 2014. View Article : Google Scholar : PubMed/NCBI
17	Yang S, Wang X, Contino G, et al: Pancreatic cancers require autophagy for tumor growth. Genes Dev. 25:717–729. 2011. View Article : Google Scholar : PubMed/NCBI
18	Edwards H, Xie C, LaFiura KM, et al: RUNX1 regulates phosphoinositide 3-kinase/AKT pathway: role in chemotherapy sensitivity in acute megakaryocytic leukemia. Blood. 114:2744–2752. 2009. View Article : Google Scholar : PubMed/NCBI
19	Xie C, Edwards H, Xu X, et al: Mechanisms of synergistic anti-leukemic interactions between valproic acid and cytarabine in pediatric acute myeloid leukemia. Clinical cancer research: an official journal of the American Association for Cancer Research. 16:5499–5510. 2010. View Article : Google Scholar : PubMed/NCBI
20	Xu X, Xie C, Edwards H, Zhou H, Buck SA and Ge Y: Inhibition of histone deacetylases 1 and 6 enhances cytarabine-induced apoptosis in pediatric acute myeloid leukemia cells. PloS One. 6:e171382011. View Article : Google Scholar : PubMed/NCBI
21	Chou TC: Theoretical basis, experimental design, and computerized simulation of synergism and antagonism in drug combination studies. Pharmacol Rev. 58:621–681. 2006. View Article : Google Scholar : PubMed/NCBI
22	Wang G, He J, Zhao J, et al: Class I and class II histone deacetylases are potential therapeutic targets for treating pancreatic cancer. PloS One. 7:e520952012. View Article : Google Scholar : PubMed/NCBI
23	Maiuri MC, Le Toumelin G, Criollo A, et al: Functional and physical interaction between Bcl-X(L) and a BH3-like domain in Beclin-1. EMBO J. 26:2527–2539. 2007. View Article : Google Scholar : PubMed/NCBI