No targeted drugs are currently available against small cell lung cancer (SCLC). BCL-2 family members are involved in apoptosis regulation and represent therapeutic targets in many malignancies.
Expression of BCL-2 family members in 27 SCLC cell lines representing all known four SCLC molecular subtypes was assessed by qPCR, Western blot and mass spectrometry-based proteomics. BCL-2 and MCL-1 inhibition (venetoclax and S63845, respectively) was assessed by MTT assay and flow cytometry and in mice bearing human SCLC tumours. Drug interactions were calculated using the Combenefit software. Ectopic BAX overexpression was achieved by expression plasmids.
The highest BCL-2 expression levels were detected in ASCL1- and POU2F3-driven SCLC cells. Although sensitivity to venetoclax was reflected by BCL-2 levels, not all cell lines responded consistently despite their high BCL-2 expression. MCL-1 overexpression and low BAX levels were both characteristic for venetoclax resistance in SCLC, whereas the expression of other BCL-2 family members did not affect therapeutic efficacy. Combination of venetoclax and S63845 resulted in significant, synergistic in vitro and in vivo anti-tumour activity and apoptosis induction in double-resistant cells; however, this was seen only in a subset with detectable BAX. In non-responding cells, ectopic BAX overexpression sensitised to venetoclax and S63845 and, furthermore, induced synergistic drug interaction.
The current study reveals the subtype specificity of BCL-2 expression and sheds light on the mechanism of venetoclax resistance in SCLC. Additionally, we provide preclinical evidence that combined BCL-2 and MCL-1 targeting is an effective approach to overcome venetoclax resistance in high BCL-2-expressing SCLCs with intact BAX.
This is a preview of subscription content, access via your institution
Subscribe to this journal
Receive 24 print issues and online access
$259.00 per year
only $10.79 per issue
Rent or buy this article
Get just this article for as long as you need it
Prices may be subject to local taxes which are calculated during checkout
Data were generated by the authors and are available on request.
Gazdar AF, Bunn PA, Minna JD. Small-cell lung cancer: what we know, what we need to know and the path forward. Nat Rev Cancer. 2017;17:725–37.
Schwendenwein A, Megyesfalvi Z, Barany N, Valko Z, Bugyik E, Lang C, et al. Molecular profiles of small cell lung cancer subtypes: therapeutic implications. Mol Ther Oncolytics. 2021;20:470–83.
Rudin CM, Brambilla E, Faivre-Finn C, Sage J. Small-cell lung cancer. Nat Rev Dis Prim. 2021;7:3.
Kahnert K, Kauffmann-Guerrero D, Huber RM. SCLC-state of the art and what does the future have in store? Clin Lung Cancer. 2016;17:325–33.
Karachaliou N, Pilotto S, Lazzari C, Bria E, de Marinis F, Rosell R. Cellular and molecular biology of small cell lung cancer: an overview. Transl Lung Cancer Res. 2016;5:2–15.
Ganti AKP, Loo BW, Bassetti M, Blakely C, Chiang A, D’Amico TA, et al. Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw. 2021;19:1441–64.
Gong J, Salgia R. Managing patients with relapsed small-cell lung cancer. J Oncol Pract. 2018;14:359–66.
Esposito G, Palumbo G, Carillio G, Manzo A, Montanino A, Sforza V, et al. Immunotherapy in small cell lung cancer. Cancers. 2020;12:2522.
Horn L, Mansfield AS, Szczęsna A, Havel L, Krzakowski M, Hochmair MJ, et al. First-line atezolizumab plus chemotherapy in extensive-stage small-cell lung cancer. N Engl J Med. 2018;379:2220–9.
Ready N, Farago AF, de Braud F, Atmaca A, Hellmann MD, Schneider JG, et al. Third-line nivolumab monotherapy in recurrent SCLC: CheckMate 032. J Thorac Oncol. 2019;14:237–44.
Rudin CM, Poirier JT, Byers LA, Dive C, Dowlati A, George J, et al. Molecular subtypes of small cell lung cancer: a synthesis of human and mouse model data. Nat Rev Cancer. 2019;19:289–97.
Drapkin BJ, Rudin CM. Advances in small-cell lung cancer (SCLC) translational research. Cold Spring Harb Perspect Med. 2021;11:a038240.
Gay CM, Stewart CA, Park EM, Diao L, Groves SM, Heeke S, et al. Patterns of transcription factor programs and immune pathway activation define four major subtypes of SCLC with distinct therapeutic vulnerabilities. Cancer Cell. 2021;39:346–60.e7.
Baine MK, Hsieh MS, Lai WV, Egger JV, Jungbluth AA, Daneshbod Y, et al. SCLC subtypes defined by ASCL1, NEUROD1, POU2F3, and YAP1: a comprehensive immunohistochemical and histopathologic characterization. J Thorac Oncol. 2020;15:1823–35.
Megyesfalvi Z, Barany N, Lantos A, Valko Z, Pipek O, Lang C, et al. Expression patterns and prognostic relevance of subtype-specific transcription factors in surgically resected small-cell lung cancer: an international multicenter study. J Pathol. 2022;257:674–86.
Huang YH, Klingbeil O, He XY, Wu XS, Arun G, Lu B, et al. POU2F3 is a master regulator of a tuft cell-like variant of small cell lung cancer. Genes Dev. 2018;32:915–28.
Lochmann TL, Floros KV, Naseri M, Powell KM, Cook W, March RJ, et al. Venetoclax Is effective in small-cell lung cancers with high BCL-2 expression. Clin Cancer Res. 2018;24:360.
Schenk RL, Strasser A, Dewson G. BCL-2: long and winding path from discovery to therapeutic target. Biochem Biophys Res Commun. 2017;482:459–69.
Campbell KJ, Tait SWG. Targeting BCL-2 regulated apoptosis in cancer. Open Biol. 2018;8:180002.
Byers LA, Wang J, Nilsson MB, Fujimoto J, Saintigny P, Yordy J, et al. Proteomic profiling identifies dysregulated pathways in small cell lung cancer and novel therapeutic targets including PARP1. Cancer Discov. 2012;2:798–811.
Anstee NS, Bilardi RA, Ng AP, Xu Z, Robati M, Vandenberg CJ, et al. Impact of elevated anti-apoptotic MCL-1 and BCL-2 on the development and treatment of MLL-AF9 AML in mice. Cell Death Differ. 2019;26:1316–31.
Pan R, Ruvolo VR, Wei J, Konopleva M, Reed JC, Pellecchia M, et al. Inhibition of Mcl-1 with the pan-Bcl-2 family inhibitor (-)BI97D6 overcomes ABT-737 resistance in acute myeloid leukemia. Blood. 2015;126:363–72.
Lochmann TL, Bouck YM, Faber AC. BCL-2 inhibition is a promising therapeutic strategy for small cell lung cancer. Oncoscience. 2018;5:218–9.
Roberts AW, Stilgenbauer S, Seymour JF, Huang DCS. Venetoclax in patients with previously treated chronic lymphocytic leukemia. Clin Cancer Res. 2017;23:4527–33.
Juárez-Salcedo LM, Desai V, Dalia S. Venetoclax: evidence to date and clinical potential. Drugs Context. 2019;8:212574.
Ben-Ezra JM, Kornstein MJ, Grimes MM, Krystal G. Small cell carcinomas of the lung express the Bcl-2 protein. Am J Pathol. 1994;145:1036–40.
Tahir SK, Smith ML, Hessler P, Rapp LR, Idler KB, Park CH, et al. Potential mechanisms of resistance to venetoclax and strategies to circumvent it. BMC Cancer. 2017;17:399.
Zhang Q, Riley-Gillis B, Han L, Jia Y, Lodi A, Zhang H, et al. Activation of RAS/MAPK pathway confers MCL-1 mediated acquired resistance to BCL-2 inhibitor venetoclax in acute myeloid leukemia. Signal Transduct Target Ther. 2022;7:51.
Szeitz B, Megyesfalvi Z, Woldmar N, Valko Z, Schwendenwein A, Barany N, et al. In-depth proteomic analysis reveals unique subtype-specific signatures in human small cell lung cancer. Clin Transl Med. 2022;12:e1060.
Kuras M, Woldmar N, Kim Y, Hefner M, Malm J, Moldvay J, et al. Proteomic workflows for high-quality quantitative proteome and post-translational modification analysis of clinically relevant samples from formalin-fixed paraffin-embedded archives. J Proteome Res. 2021;20:1027–39.
Szeitz B, Woldmar N, Valko Z, Megyesfalvi Z, Barany N, Paku S, et al. Proteomic characterization of small cell lung cancer subtypes. 16th Annual US HUPO Conference; Seattle Washington, USA, 2020.
Laszlo V, Valko Z, Ozsvar J, Kovacs I, Garay T, Hoda MA, et al. The FAK inhibitor BI 853520 inhibits spheroid formation and orthotopic tumor growth in malignant pleural mesothelioma. J Mol Med. 2019;97:231–42.
Kilkenny C, Browne WJ, Cuthill IC, Emerson M, Altman DG. Improving bioscience research reporting: the ARRIVE guidelines for reporting animal research. PLoS Biol. 2010;8:e1000412.
Torok S, Rezeli M, Kelemen O, Vegvari A, Watanabe K, Sugihara Y, et al. Limited tumor tissue drug penetration contributes to primary resistance against angiogenesis inhibitors. Theranostics. 2017;7:400–12.
Costanzo F, Martínez Diez M, Santamaría Nuñez G, Díaz-Hernandéz JI, Genes Robles CM, Díez, et al. Promoters of ASCL1- and NEUROD1-dependent genes are specific targets of lurbinectedin in SCLC cells. EMBO Mol Med. 2022;14:e14841.
Augustyn A, Borromeo M, Wang T, Fujimoto J, Shao C, Dospoy PD, et al. ASCL1 is a lineage oncogene providing therapeutic targets for high-grade neuroendocrine lung cancers. Proc Natl Acad Sci USA. 2014;111:14788–93.
Knelson EH, Patel SA, Sands JM. PARP inhibitors in small-cell lung cancer: rational combinations to improve responses. Cancers. 2021;13:727.
Dutta C, Day T, Kopp N, van Bodegom D, Davids MS, Ryan J, et al. BCL2 suppresses PARP1 function and nonapoptotic cell death. Cancer Res. 2012;72:4193–203.
Punnoose EA, Leverson JD, Peale F, Boghaert ER, Belmont LD, Tan N, et al. Expression profile of BCL-2, BCL-XL, and MCL-1 predicts pharmacological response to the BCL-2 selective antagonist venetoclax in multiple myeloma models. Mol Cancer Ther. 2016;15:1132–44.
Yue X, Chen Q, He J. Combination strategies to overcome resistance to the BCL2 inhibitor venetoclax in hematologic malignancies. Cancer Cell Int. 2020;20:524.
Bose P, Gandhi V, Konopleva M. Pathways and mechanisms of venetoclax resistance. Leuk Lymphoma. 2017;58:1–17.
Fresquet V, Rieger M, Carolis C, García-Barchino MJ, Martinez-Climent JA. Acquired mutations in BCL2 family proteins conferring resistance to the BH3 mimetic ABT-199 in lymphoma. Blood. 2014;123:4111–9.
Yasuda Y, Ozasa H, Kim YH, Yamazoe M, Ajimizu H, Yamamoto Funazo T, et al. MCL1 inhibition is effective against a subset of small-cell lung cancer with high MCL1 and low BCL-X(L) expression. Cell Death Dis. 2020;11:177.
Wang Y, Wang Y, Fan X, Song J, Wu H, Han J, et al. ABT-199-mediated inhibition of Bcl-2 as a potential therapeutic strategy for nasopharyngeal carcinoma. Biochem Biophys Res Commun. 2018;503:1214–20.
Moujalled DM, Pomilio G, Ghiurau C, Ivey A, Salmon J, Rijal S, et al. Combining BH3-mimetics to target both BCL-2 and MCL1 has potent activity in pre-clinical models of acute myeloid leukemia. Leukemia. 2019;33:905–17.
Prukova D, Andera L, Nahacka Z, Karolova J, Svaton M, Klanova M, et al. Cotargeting of BCL2 with venetoclax and MCL1 with S63845 is synthetically lethal in vivo in relapsed mantle cell lymphoma. Clin Cancer Res. 2019;25:4455–65.
Seiller C, Maiga S, Touzeau C, Bellanger C, Kervoëlen C, Descamps G, et al. Dual targeting of BCL2 and MCL1 rescues myeloma cells resistant to BCL2 and MCL1 inhibitors associated with the formation of BAX/BAK hetero-complexes. Cell Death Dis. 2020;11:316.
Algarín EM, Díaz-Tejedor A, Mogollón P, Hernández-García S, Corchete LA, San-Segundo L, et al. Preclinical evaluation of the simultaneous inhibition of MCL-1 and BCL-2 with the combination of S63845 and venetoclax in multiple myeloma. Haematologica. 2020;105:e116–20.
Siu KT, Huang C, Panaroni C, Mukaihara K, Fulzele K, Soucy R, et al. BCL2 blockade overcomes MCL1 resistance in multiple myeloma. Leukemia. 2019;33:2098–102.
Souers AJ, Leverson JD, Boghaert ER, Ackler SL, Catron ND, Chen J, et al. ABT-199, a potent and selective BCL-2 inhibitor, achieves antitumor activity while sparing platelets. Nat Med. 2013;19:202–8.
Kotschy A, Szlavik Z, Murray J, Davidson J, Maragno AL, Le Toumelin-Braizat G, et al. The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models. Nature. 2016;538:477–82.
Sundararajan R, Cuconati A, Nelson D, White E. Tumor Necrosis Factor-alpha induces Bax-Bak interaction and apoptosis, which is inhibited by adenovirus E1B 19K. J Biol Chem. 2001;276:45120–7.
Debernardi J, Hollville E, Lipinski M, Wiels J, Robert A. Differential role of FL-BID and t-BID during verotoxin-1-induced apoptosis in Burkitt’s lymphoma cells. Oncogene. 2018;37:2410–21.
We thank Barbara Dekan, Barbara Peter-Vörösmarty and Erzsebet Nagy for technical assistance and Nicole Woldmar and Beáta Szeitz for their help with the proteomic analyses.
KS was supported the Austrian Science Fund (FWF No. T 1062-B33) and the City of Vienna Fund for Innovative Interdisciplinary Cancer Research. BD, ZM and AR acknowledge funding from the Hungarian National Research, Development and Innovation Office (KH130356 to BD; 2020-1.1.6-JÖVŐ and TKP2021-EGA-33 to BD and ZM; FK-143751 to BD, ZM and AH-R). BD was also supported by the Austrian Science Fund (FWF I3522, FWF I3977 and I4677). ZM was supported by the UNKP-20-3 and UNKP-21-3 New National Excellence Program of the Ministry for Innovation and Technology of Hungary and by the Hungarian Respiratory Society (MPA #2020). ZM is recipient of the IASLC/ILCF Young Investigator Grant 2023. VL is a recipient of the Bolyai Research Scholarship of the Hungarian Academy of Sciences and the UNKP-19-4 New National Excellence Program of the Ministry for Innovation and Technology. MG was supported by the City of Vienna Fund for Innovative Interdisciplinary Cancer Research and the Berndorf Private Foundation. MR acknowledges funding from the Mrs. Berta Kamprad´s Cancer Foundation (FBKS-2020-22-(291)).
The authors declare no competing interests.
Ethics approval and consent to participate
All mentioned animal experiments were performed according to the ARRIVE guidelines and to the animal welfare regulations of the host institutes (permission number: PEI/001/2574-6/2015).
Consent for publication
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Valko, Z., Megyesfalvi, Z., Schwendenwein, A. et al. Dual targeting of BCL-2 and MCL-1 in the presence of BAX breaks venetoclax resistance in human small cell lung cancer. Br J Cancer (2023). https://doi.org/10.1038/s41416-023-02219-9