Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

BCL9/BCL9L promotes tumorigenicity through immune-dependent and independent mechanisms in triple negative breast cancer


Treatment of patients with triple-negative breast cancer (TNBC) has been challenging due to a lack of well-defined molecular targets. The Wnt/β-catenin pathway is known to be activated in many TNBC patients and BCL9 and BCL9L are important transcriptional co-activators of β-catenin, but whether inhibition of BCL9/BCL9L can suppress TNBC growth and the underlying mechanism are not fully understood. Here we demonstrate that the expression of BCL9 and BCL9L is directly correlated with malignancy in TNBC patient tumors and that BCL9 and BCL9L promote tumor cell growth, cell migration and metastasis in TNBC models. Mechanistically, we found that BCL9/BCL9L promotes tumorigenicity through both the Wnt and TGF-β pathways. Besides, BCL9/BCL9L expression inversely correlates with CD8+ T cell infiltration in TNBC and BCL9/BCL9L inhibits the infiltration of CD8+ T cells in the tumor microenvironment. hsBCL9CT-24, an inhibitor of BCL9/β-catenin peptides, promotes intratumoral infiltration of cytotoxic T cells, reducing regulatory T cells (Treg) and increasing dendritic cells (DCs). Inhibition of BCL9/BCL9L and TGF-β suppresses activity of Treg. TGF-β signaling increases tumor infiltration of cytotoxic CD8+ T cells. In accordance, genetic or pharmacological inhibition of BCL9/BCL9L synergizes with PD-1/L1 antibodies to inhibit tumor growth. In summary, these results suggest that targeting BCL9/BCL9L has a direct anti-tumor effect and also unleashes an anti-cancer immune response through inhibition of both Wnt and TGF-β signaling, suggesting a viable therapeutic approach for TNBC treatment.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: BCL9 expression is associated with malignant TNBC phenotypes.
Fig. 2: BCL9 expression correlates with immune cell tumor infiltration.
Fig. 3: BCL9 promotes tumor growth and experimental liver metastasis in TNBC mouse models.
Fig. 4: Depletion of BCL9 and BCL9L promotes infiltration of CD8+ T cells in the tumor microenvironment and synergizes with PD-1 antibody to attenuate TNBC progression.
Fig. 5: BCL9 mediates TGF-β pathway expression in TNBC cells.
Fig. 6: Inhibition of Bcl9 modulates tumor immune microenvironment and reactivates anticancer immunity.

Data availability

The datasets analyzed during the current study are available in the figshare repository at


  1. 1.

    Nusse R, Clevers H. Wnt/β-catenin signaling, disease, and emerging therapeutic modalities. Cell. 2017;169:985–99.

    CAS  PubMed  Google Scholar 

  2. 2.

    Liu J, Pan S, Hsieh MH, Ng N, Sun F, Wang T, et al. Targeting Wnt-driven cancer through the inhibition of Porcupine by LGK974. Proc Natl Acad Sci U.S.A. 2013;110:20224–9.

    CAS  PubMed  PubMed Central  Google Scholar 

  3. 3.

    Adachi S, Jigami T, Yasui T, Nakano T, Ohwada S, Omori Y, et al. Role of a BCL9-related beta-catenin-binding protein, B9L, in tumorigenesis induced by aberrant activation of Wnt signaling. Cancer Res. 2004;64:8496–501.

    CAS  PubMed  Google Scholar 

  4. 4.

    Gay DM, Ridgway RA, Müller M, Hodder MC, Hedley A, Clark W, et al. Loss of BCL9/9l suppresses Wnt driven tumourigenesis in models that recapitulate human cancer. Nat Commun. 2019;10:723.

    CAS  PubMed  PubMed Central  Google Scholar 

  5. 5.

    Mani M, Carrasco DE, Zhang Y, Takada K, Gatt ME, Dutta-Simmons J, et al. BCL9 promotes tumor progression by conferring enhanced proliferative, metastatic, and angiogenic properties to cancer cells. Cancer Res. 2009;69:7577–86.

    CAS  PubMed  PubMed Central  Google Scholar 

  6. 6.

    De la Roche M, Worm J, Bienz M. The function of BCL9 in Wnt/β-catenin signaling and colorectal cancer cells. BMC Cancer. 2008;8:199.

    PubMed  PubMed Central  Google Scholar 

  7. 7.

    Elsarraj HS, Hong Y, Valdez KE, Michaels W, Hook M, Smith WP, et al. Expression profiling of in vivo ductal carcinoma in situ progression models identified B cell lymphoma-9 as a molecular driver of breast cancer invasion. Breast Cancer Res. 2015;17:128.

    PubMed  PubMed Central  Google Scholar 

  8. 8.

    Zatula N, Wiese M, Bunzendahl J, Birchmeier W, Perske C, Bleckmann A, et al. The BCL9-2 proto-oncogene governs estrogen receptor alpha expression in breast tumorigenesis. Oncotarget. 2014;5:6770.

    PubMed  PubMed Central  Google Scholar 

  9. 9.

    Pardoll DM. The blockade of immune checkpoints in cancer immunotherapy. Nat Rev Cancer. 2012;12:252–64.

    CAS  PubMed  PubMed Central  Google Scholar 

  10. 10.

    Michot J, Bigenwald C, Champiat S, Collins M, Carbonnel F, Postel-Vinay S, et al. Immune-related adverse events with immune checkpoint blockade: a comprehensive review. Eur J Cancer. 2016;54:139–48.

    CAS  PubMed  Google Scholar 

  11. 11.

    Rizvi NA, Mazières J, Planchard D, Stinchcombe TE, Dy GK, Antonia SJ, et al. Activity and safety of nivolumab, an anti-PD-1 immune checkpoint inhibitor, for patients with advanced, refractory squamous non-small-cell lung cancer (CheckMate 063): a phase 2, single-arm trial. Lancet Onco. 2015;16:257–65.

    CAS  Google Scholar 

  12. 12.

    Brahmer JR, Tykodi SS, Chow LQ, Hwu W-J, Topalian SL, Hwu P, et al. Safety and activity of anti–PD-L1 antibody in patients with advanced cancer. N. Engl J Med. 2012;366:2455–65.

    CAS  PubMed  PubMed Central  Google Scholar 

  13. 13.

    Schmid P, Adams S, Rugo HS, Schneeweiss A, Barrios CH, Iwata H, et al. Atezolizumab and nab-paclitaxel in advanced triple-negative breast cancer. N. Engl J Med. 2018;379:2108–21.

    CAS  PubMed  Google Scholar 

  14. 14.

    Feng M, Jin J, Xia L, Xiao T, Mei S, Wang X, et al. Pharmacological inhibition of β-catenin/BCL9 interaction overcomes resistance to immune checkpoint blockades by modulating Treg cells. Sci Adv. 2019;5:eaau5240.

    CAS  PubMed  PubMed Central  Google Scholar 

  15. 15.

    Ovcaricek T, Frkovic SG, Matos E, Mozina B, Borstnar S. Triple negative breast cancer — prognostic factors and survival. Radio Oncol. 2011;45:46–52.

    Google Scholar 

  16. 16.

    Foulkes WD, Smith IE, Reis-Filho JS. Triple-negative breast cancer. N. Engl J Med. 2010;363:1938–48.

    CAS  PubMed  Google Scholar 

  17. 17.

    Lehmann BD, Bauer JA, Chen X, Sanders ME, Chakravarthy AB, Shyr Y, et al. Identification of human triple-negative breast cancer subtypes and preclinical models for selection of targeted therapies. J Clin Invest. 2011;121:2750–67.

    CAS  PubMed  PubMed Central  Google Scholar 

  18. 18.

    Pohl S-G, Brook N, Agostino M, Arfuso F, Kumar AP, Dharmarajan A. Wnt signaling in triple-negative breast cancer. Oncogenesis. 2017;6:e310.

    CAS  PubMed  PubMed Central  Google Scholar 

  19. 19.

    Bilir B, Kucuk O, Moreno CS. Wnt signaling blockage inhibits cell proliferation and migration, and induces apoptosis in triple-negative breast cancer cells. J Transl Med. 2013;11:280.

    PubMed  PubMed Central  Google Scholar 

  20. 20.

    Wend P, Runke S, Wend K, Anchondo B, Yesayan M, Jardon M, et al. WNT10B/β‐catenin signalling induces HMGA2 and proliferation in metastatic triple‐negative breast cancer. EMBO Mol Med. 2013;5:264–79.

    CAS  PubMed  PubMed Central  Google Scholar 

  21. 21.

    Bhola NE, Balko JM, Dugger TC, Kuba MG, Sánchez V, Sanders M, et al. TGF-β inhibition enhances chemotherapy action against triple-negative breast cancer. J Clin Invest. 2013;123:1348–58.

    CAS  PubMed  PubMed Central  Google Scholar 

  22. 22.

    Tauriello DV, Palomo-Ponce S, Stork D, Berenguer-Llergo A, Badia-Ramentol J, Iglesias M, et al. TGFβ drives immune evasion in genetically reconstituted colon cancer metastasis. Nature. 2018;554:538–43.

    CAS  PubMed  Google Scholar 

  23. 23.

    Fu CM, Liang XJ, Cui WG, Ober-Blobaum JL, Vazzana J, Shrikant PA, et al. beta-Catenin in dendritic cells exerts opposite functions in cross-priming and maintenance of CD8(+) T cells through regulation of IL-10. P Natl Acad Sci U.S.A. 2015;112:2823–8.

    CAS  Google Scholar 

  24. 24.

    Spranger S, Gajewski TF. A new paradigm for tumor immune escape: β-catenin-driven immune exclusion. J Immunother Cancer. 2015;3:43.

    PubMed  PubMed Central  Google Scholar 

  25. 25.

    Augustin I, Dewi DL, Hundshammer J, Rempel E, Brunk F, Boutros M. Immune cell recruitment in teratomas is impaired by increased Wnt secretion. Stem Cell Res. 2016;17:607–15.

    CAS  PubMed  Google Scholar 

  26. 26.

    Gattinoni L, Ji Y, Restifo NP. Wnt/beta-catenin signaling in T-cell immunity and cancer immunotherapy. Clin Cancer Res. 2010;16:4695–701.

    CAS  PubMed  PubMed Central  Google Scholar 

  27. 27.

    Hong Y, Manoharan I, Suryawanshi A, Majumdar T, Angus-Hill ML, Koni PA, et al. beta-catenin promotes regulatory T-cell responses in tumors by inducing vitamin A metabolism in dendritic cells. Cancer Res. 2015;75:656–65.

    CAS  PubMed  PubMed Central  Google Scholar 

  28. 28.

    Togashi Y, Shitara K, Nishikawa H. Regulatory T cells in cancer immunosuppression—implications for anticancer therapy. Nat Rev Clin Oncol. 2019;16:356–71.

    CAS  PubMed  Google Scholar 

  29. 29.

    Golovina TN, Vonderheide RH. Regulatory T cells: overcoming suppression of T-cell immunity. Cancer J. 2010;16:342–7.

    CAS  PubMed  Google Scholar 

  30. 30.

    van Loosdregt J, Fleskens V, Tiemessen MM, Mokry M, van Boxtel R, Meerding J, et al. Canonical Wnt signaling negatively modulates regulatory T cell function. Immunity. 2013;39:298–310.

    PubMed  Google Scholar 

  31. 31.

    Xu Y, Yang Z, Yuan H, Li Z, Li Y, Liu Q, et al. PCDH10 inhibits cell proliferation of multiple myeloma via the negative regulation of the Wnt/β-catenin/BCL-9 signaling pathway. Oncol Rep. 2015;34:747–54.

    CAS  PubMed  Google Scholar 

  32. 32.

    Jiang Y-Z, Ma D, Suo C, Shi J, Xue M, Hu X, et al. Genomic and transcriptomic landscape of triple-negative breast cancers: subtypes and treatment strategies. Cancer Cell. 2019;35:428–40. e425.

    CAS  PubMed  Google Scholar 

  33. 33.

    Massagué J, Seoane J, Wotton D. Smad transcription factors. Genes Dev. 2005;19:2783–810.

    PubMed  Google Scholar 

  34. 34.

    Mahmoud SM, Paish EC, Powe DG, Macmillan RD, Grainge MJ, Lee AH. et al.Tumor-infiltrating CD8+ lymphocytes predict clinical outcome in breast cancer.J Clin Oncol. 2011;29:1949–55.

    Google Scholar 

  35. 35.

    Ahmadzadeh M, Rosenberg SA. TGF-β1 attenuates the acquisition and expression of effector function by tumor antigen-specific human memory CD8 T cells. J Immunol. 2005;174:5215–23.

    CAS  PubMed  PubMed Central  Google Scholar 

  36. 36.

    Savas P, Virassamy B, Ye C, Salim A, Mintoff CP, Caramia F, et al. Single-cell profiling of breast cancer T cells reveals a tissue-resident memory subset associated with improved prognosis. Nat Med. 2018;24:986.

    CAS  PubMed  Google Scholar 

  37. 37.

    Takada K, Zhu D, Bird GH, Sukhdeo K, Zhao J-J, Mani M, et al. Targeted disruption of the BCL9/β-catenin complex inhibits oncogenic Wnt signaling. Sci Transl Med. 2012;4:148ra117–148ra117.

    PubMed  PubMed Central  Google Scholar 

  38. 38.

    Yun M-S, Kim S-E, Jeon SH, Lee J-S, Choi K-Y. Both ERK and Wnt/β-catenin pathways are involved in Wnt3a-induced proliferation. J Cell Sci. 2005;118:313–22.

    CAS  PubMed  Google Scholar 

  39. 39.

    Atezolizumab Combo Approved for PD-L1-positive TNBC. Cancer Discov. 2019; 9: OF2.

  40. 40.

    MacDonald BT, Tamai K, He X. Wnt/β-catenin signaling: components, mechanisms, and diseases. Dev Cell. 2009;17:9–26.

    CAS  PubMed  PubMed Central  Google Scholar 

  41. 41.

    Josefowicz SZ, Lu LF, Rudensky AY. Regulatory T cells: mechanisms of differentiation and function. Annu Rev Immunol. 2012;30:531–64.

    CAS  PubMed  PubMed Central  Google Scholar 

  42. 42.

    Galluzzi L, Spranger S, Fuchs E, López-Soto A. WNT signaling in cancer immunosurveillance. Trends Cell Biol. 2019;29:44–65.

    CAS  PubMed  Google Scholar 

  43. 43.

    Sharma P, Hu-Lieskovan S, Wargo JA, Ribas A. Primary, adaptive, and acquired resistance to cancer immunotherapy. Cell. 2017;168:707–23.

    CAS  PubMed  PubMed Central  Google Scholar 

  44. 44.

    Parveen S, Siddharth S, Cheung L, Murphy JR, Sharma D, Bishai WR. Transient depletion of MDSCs and Tregs asan effective immunotherapy against triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the AACR Special Conference on TumorImmunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A54.

  45. 45.

    He Y, Jiang Z, Chen C, Wang X. Classification of triple-negative breast cancers based on Immunogenomic profiling. J Exp Clin Canc Res. 2018;37:327.

    CAS  Google Scholar 

  46. 46.

    King TD, Suto MJ, Li Y. The wnt/β‐catenin signaling pathway: a potential therapeutic target in the treatment of triple negative breast cancer. J Cell Biochem. 2012;113:13–18.

    CAS  PubMed  Google Scholar 

  47. 47.

    Guo X, Ramirez A, Waddell DS, Li Z, Liu X. Wang X-F. Axin and GSK3-β control Smad3 protein stability and modulate TGF-β signaling. Genes Dev. 2008;22:106–20.

    CAS  PubMed  PubMed Central  Google Scholar 

  48. 48.

    Baron V, Adamson ED, Calogero A, Ragona G, Mercola D. The transcription factor Egr1 is a direct regulator of multiple tumor suppressors including TGFβ1, PTEN, p53, and fibronectin. Cancer Gene Ther. 2006;13:115.

    CAS  PubMed  PubMed Central  Google Scholar 

  49. 49.

    Yang L, Pang Y, Moses HL. TGF-β and immune cells: an important regulatory axis in the tumor microenvironment and progression. Trends Immunol. 2010;31:220–7.

    CAS  PubMed  PubMed Central  Google Scholar 

  50. 50.

    Salgado R, Denkert C, Campbell C, Savas P, Nuciforo P, Aura C, et al. Tumor-infiltrating lymphocytes and associations with pathological complete response and event-free survival in HER2-positive early-stage breast cancer treated with lapatinib and trastuzumab: a secondary analysis of the NeoALTTO trial. JAMA Oncol. 2015;1:448–55.

    PubMed  PubMed Central  Google Scholar 

Download references


The current study was supported by projects on the National Natural Science Foundation of China (81373442) (KY), National Science and Technology Major Project of China (2018ZX09711002–008) (KY), the National Basic Research Program (973 Program) of China (2013CB932500) (KY), the Science and Technology Commission of Shanghai (18ZR1403900, 18JC1413800) (DZ), the National Natural Science Foundation of China (81872895) (DZ), and the project on joint translational research in the School of Pharmacy and Minhang Hospital (RO-MY201712) (DZ).

Author information



Corresponding authors

Correspondence to Ker Yu or Di Zhu.

Ethics declarations

Conflict of interest

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wang, X., Feng, M., Xiao, T. et al. BCL9/BCL9L promotes tumorigenicity through immune-dependent and independent mechanisms in triple negative breast cancer. Oncogene 40, 2982–2997 (2021).

Download citation


Quick links