Natural Dibenzo[b,f]oxepines, Pacharin and Bauhiniastatin-1, Isolated from Bauhinia acuruana Induce Apoptosis on Breast Cancer Cells via MCL-1 Protein Reduction

Abstract

Herein, we describe the antiproliferative effects of two natural dibenzo [b,f]oxepines, pacharin and bauhiniastatin-1, isolated from Bauhinia acuruana on a breast cancer cell line and the mode of action underlying the cytotoxicity. Both compounds were cytotoxic in a panel of six tumor lines analyzed by the MTT assay, and IC₅₀ values ranged from 7.8 to 45.1 µM, including human breast adenocarcinoma (MCF-7) cells. In contrast, none of the compounds were cytotoxic on normal human peripheral blood mononuclear cells (IC₅₀ > 100 µM). Human breast adenocarcinoma (MCF-7) cells treated with pacharin or bauhiniastatin-1 20 µM for 24 h presented a reduction in cell volume and intensification of chromatin condensation, DNA fragmentation, and apoptotic cells. These findings became more evident after 48 h of exposure. Antiapoptotic B-cell lymphoma-2 family members, such as myeloid cell leukemia-1 and B-cell lymphoma-extra large, are important targets in cancer cells since their overexpression confers resistance to cancer treatments. A significant reduction of the myeloid cell leukemia-1 protein levels in human breast adenocarcinoma (MCF-7) cells after 24 h of treatment with pacharin or bauhiniastatin-1 at 20 µM was observed, while the B-cell lymphoma-extra large protein content was reduced in bauhiniastatin-1-treated cells at 40 µM only. The cytotoxic effects of pacharin and bauhiniastatin-1 are likely linked to myeloid cell leukemia-1 inhibition, which leads to the apoptosis of breast adenocarcinoma cells.

Key words

Bauhinia acuruana - Fabaceae - pacharin - bauhiniastatin-1 - breast adenocarcinoma - MCL-1 - Bcl-xL - apoptosis

• References

• 1 Vaz AMST, Tozzi AMGA. Bauhinia ser. Cansenia (Leguminosae: Caesalpinioideae) no Brasil. Rodriguésia 2003; 54: 55-143
• 2 Garbicz D, Tobiasz P, Borys F, Pilżys T, Marcinkowski M, Poterała M, Grzesiuk E, Krawczyk H. The stilbene and dibenzo [b,f]oxepine derivatives as anticancer compounds. Biomed Pharmacother 2020; 123: 109781
• 3 Góis RWS, De Sousa LM, Santiago GMP, Romero NR, Lemos TLG, Arriaga AMC, Braz-Filho R. Larvicidal activity against Aedesaegypti of pacharin from Bauhinia acuruana . Parasitol Res 2013; 112: 2753-2757
• 4 Góis RWS, De Sousa LM, Da Silva HC, Da Silva FEF, Pimenta ATA, Lima MAS, Arriaga AMC, Lemos TLG, Braz-Filho R, Militao GCG, Da Silva PBN, Goncalves FJT, Santiago GMP. Chemical constituents from Bauhinia acuruana and their cytotoxicity. Rev Bras Farmacogn 2017; 27: 711-715
• 5 Pettit GR, Numata A, Iwamoto C, Usami Y, Yamada T, Ohishi H, Cragg GM. Antineoplastic agents. 551. Isolation and structures of bauhiniastatins 1–4 from Bauhinia purpurea . J Nat Prod 2006; 69: 323-327
• 6 Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F. Global Cancer Statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2021; 71: 209-249
• 7 Hata AN, Engelman JA, Faber AC. The BCL2 family: Key mediators of the apoptotic response to targeted anticancer therapeutics. Cancer Discov 2015; 5: 475-487
• 8 Akgul C. Mcl-1 is a potential therapeutic target in multiple types of cancer. Cell Mol Life Sci 2009; 66: 1326-1336
• 9 Wang H, Guo M, Wei H, Chen Y. Targeting MCL-1 in cancer: current status and perspectives. J Hematol Oncol 2021; 14: 67
• 10 Modugno M, Banfi P, Gasparri F, Borzilleri R, Carter P, Cornelius L, Gottardis M, Lee V, Mapelli C, Naglich JG, Tebben A, Vite G, Pastori W, Albanese C, Corti E, Ballinari D, Galvani A. Mcl-1 antagonism is a potential therapeutic strategy in a subset of solid cancers. Exp Cell Res 2015; 332: 267-277
• 11 Mitchell C, Yacoub A, Hossein H, Martin AP, Bareford MD, Eulitt P, Yang C, Nephew KP, Dent P. Inhibition of MCL-1 in breast cancer cells promotes cell death in vitro and in vivo . Cancer Biol Ther 2010; 10: 903-917
• 12 Anjaneyulu ASR, Reddy AVR, Reddy DSK, Ward RS, Adhikesavalu D, Cameron TS. Pacharin: a new dibenzo(2, 3–6, 7)oxepin derivative from Bauhinia racemosa Lank. Tetrahedron 1984; 40: 4245-4252
• 13 Galluzzi L, Vitale I, Aaronson SA, Abrams JM, Adam D, Agostinis P, Alnemri ES, Altucci L, Amelio I, Andrews DW, Annicchiarico-Petruzzelli M, Antonov AV, Arama E, Baehrecke EH, Barlev NA, Bazan NG, Bernassola F, Bertrand MJM, Bianchi K, Blagosklonny MV, Blomgren K, Borner C, Boya P, Brenner C, Campanella M, Candi E, Carmona-Gutierrez D, Cecconi F, Chan FK, Chandel NS, Cheng EH, Chipuk JE, Cidlowski JA, Ciechanover A, Cohen GM, Conrad M, Cubillos-Ruiz JR, Czabotar PE, DʼAngiolella V, Dawson TM, Dawson VL, De Laurenzi V, De Maria R, Debatin KM, DeBerardinis RJ, Deshmukh M, Di Daniele N, Di Virgilio F, Dixit VM, Dixon SJ, Duckett CS, Dynlacht BD, El-Deiry WS, Elrod JW, Fimia GM, Fulda S, García-Sáez AJ, Garg AD, Garrido C, Gavathiotis E, Golstein P, Gottlieb E, Green DR, Greene LA, Gronemeyer H, Gross A, Hajnoczky G, Hardwick JM, Harris IS, Hengartner MO, Hetz C, Ichijo H, Jäättelä M, Joseph B, Jost PJ, Juin PP, Kaiser WJ, Karin M, Kaufmann T, Kepp O, Kimchi A, Kitsis RN, Klionsky DJ, Knight RA, Kumar S, Lee SW, Lemasters JJ, Levine B, Linkermann A, Lipton SA, Lockshin RA, López-Otín C, Lowe SW, Luedde T, Lugli E, MacFarlane M, Madeo F, Malewicz M, Malorni W, Manic G, Marine JC, Martin SJ, Martinou JC, Medema JP, Mehlen P, Meier P, Melino S, Miao EA, Molkentin JD, Moll UM, Muñoz-Pinedo C, Nagata S, Nuñez G, Oberst A, Oren M, Overholtzer M, Pagano M, Panaretakis T, Pasparakis M, Penninger JM, Pereira DM, Pervaiz S, Peter ME, Piacentini M, Pinton P, Prehn JHM, Puthalakath H, Rabinovich GA, Rehm M, Rizzuto R, Rodrigues CMP, Rubinsztein DC, Rudel T, Ryan KM, Sayan E, Scorrano L, Shao F, Shi Y, Silke J, Simon HU, Sistigu A, Stockwell BR, Strasser A, Szabadkai G, Tait SWG, Tang D, Tavernarakis N, Thorburn A, Tsujimoto Y, Turk B, Vanden Berghe T, Vandenabeele P, Vander Heiden MG, Villunger A, Virgin HW, Vousden KH, Vucic D, Wagner EF, Walczak H, Wallach D, Wang Y, Wells JA, Wood W, Yuan J, Zakeri Z, Zhivotovsky B, Zitvogel L, Melino G, Kroemer G. Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018. Cell Death Differ 2018; 25: 486-541
• 14 Hanahan D, Weinberg RA. Hallmarks of cancer: the next generation. Cell 2011; 144: 646-674
• 15 DʼAguanno S, Del Bufalo D. Inhibition of anti-apoptotic Bcl-2 proteins in preclinical and clinical studies: current overview in cancer. Cells 2020; 9: 1287
• 16 Youle RJ, Strasser A. The BCL-2 protein family: opposing activities that mediate cell death. Nat Rev Mol Cell Biol 2008; 9: 47-59
• 17 Kotschy A, Szlavik Z, Murray J, Davidson J, Maragno AL, Le Toumelin-Braizat G, Chanrion M, Kelly GL, Gong JN, Moujalled DM, Bruno A, Csekei M, Paczal A, Szabo ZB, Sipos S, Radics G, Proszenyak A, Balint B, Ondi L, Blasko G, Robertson A, Surgenor A, Dokurno P, Chen I, Matassova N, Smith J, Pedder C, Graham C, Studeny A, Lysiak-Auvity G, Girard AM, Gravé F, Segal D, Riffkin CD, Pomilio G, Galbraith LC, Aubrey BJ, Brennan MS, Herold MJ, Chang C, Guasconi G, Cauquil N, Melchiore F, Guigal-Stephan N, Lockhart B, Colland F, Hickman JA, Roberts AW, Huang DC, Wei AH, Strasser A, Lessene G, Geneste O. The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models. Nature 2016; 538: 477-482
• 18 Campbell KJ, Mason SM, Winder ML, Willemsen R, Cloix C, Lawson H, Rooney N, Dhayade S, Sims AH, Blyth K, Tait S. Breast cancer dependence on MCL-1 is due to its canonical anti-apoptotic function. Cell Death Differ 2021; 28: 2589-2600