Oral Presentation 11th Annual Conference of the International Chemical Biology Society 2022

Targeting MKK3-induced MYC activation to reduce racial disparity in breast cancer (#44)

Sophia West 1 2 , Xuan Yang 1 2 , Dacheng Fan 1 2 , Yoon H Oum 1 2 , Min Qui 1 2 , Yuhong Du 1 2 3 , Haian Fu 1 2 3 4 , Andrey A Ivanov 1 2 3
  1. Emory Chemical Biology Discovery Center, Emory University School of Medicine, Emory University, Atlanta, GA, United States
  2. Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Emory University, Atlanta, GA, United States
  3. Winship Cancer Institute, Emory University, Atlanta, GA, United States
  4. Department of Hematology & Medical Oncology, Emory University, Atlanta, GA, United States

Breast cancer is the most common cancer in women. The triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer. African American women are >40% more likely to die from breast cancer than women of other ethnicities. However, the molecular bases for the racial disparity in TNBC survival are unclear, and the lack of targeted TNBC therapy poses a critical barrier to breast cancer treatment. To overcome this barrier new non-surgical approaches are urgently needed. We address this unmet medical need by developing novel computational methods combined with experimental chemical biology and high-throughput screening (HTS) technologies. Using our specially designed bioinformatics workflow, we discovered that high expression of mitogen-activated protein kinase kinase 3 (MKK3) strongly correlates with worsened clinical outcomes in African American TNBC patients. The analysis of TNBC patient genomic profiles revealed that MKK3 promotes TNBC in part by activating the major tumor driver transcription factor MYC. MYC is a highly appealing therapeutic target in TNBC, however, no approved MYC inhibitors are available. We found that MKK3 binds and activates MYC through protein-protein interaction (PPI) in TNBC cells. Both genetic and pharmacological inhibition of the MKK3/MYC complex suppresses MYC activity and the viability of TNBC cells. Thus, MKK3/MYC interaction represents a novel vulnerability for therapeutic intervention in TNBC. By combining computational modeling with experimental HTS, we have discovered the first small molecule MKK3/MYC PPI inhibitors. For example, a quinoline derivative SGI-1027 disrupts the MKK3/MYC complex in cells and in vitro, inhibits MYC transcriptional activity, and suppresses the viability of TNBC cells. Together, our studies revealed a novel mechanism of TNBC tumorigenesis through MKK3-induced MYC activation, defined the MKK3/MYC complex as a promising druggable target to control TNBC progression, and may open new clinical strategies to reduce racial disparity in TNBC mortality.

  1. Yang X, Amgad M, Cooper LAD, Du Y, Fu H, Ivanov AA. High expression of MKK3 is associated with worse clinical outcomes in African American breast cancer patients. J Transl Med. 2020 Sep 1;18(1):334. doi: 10.1186/s12967-020-02502-w. PMID: 32873298; PMCID: PMC7465409.
  2. Yang X, Fan D, Troha AH, Ahn HM, Qian K, Liang B, Du Y, Fu H, Ivanov AA. Discovery of the first chemical tools to regulate MKK3-mediated MYC activation in cancer. Bioorg Med Chem. 2021 Sep 1;45:116324. doi: 10.1016/j.bmc.2021.116324. Epub 2021 Jul 22. PMID: 34333394; PMCID: PMC8456368.
  3. Acknowledgements: This work was supported in part by NCI’s Informatics Technology for Cancer Research (ITCR) Program (R21CA274620, A.A.I.), Mary Kay Ash Foundation Grant for Cancer Research (A.A.I.), Winship Cancer Institute #IRG-17-181-06 from the American Cancer Society (A.A.I.). Emory initiative on Biological Discovery through Chemical Innovation (A.A.I.), Cancer Target Discovery and Development (CTD2) Network (U01CA217875, H.F.), NCI Emory Lung Cancer SPORE (P50CA217691, H.F.), Career Enhancement Program (A.A.I., P50CA217691), Winship Cancer Institute (NIH 5P30CA138292).