Poster Presentation 50th Lorne Proteins Conference 2025

Uncovering the differential function and expression of DCLK1 isoforms in aggressive cancers (#123)

Lyn R. Deng 1 2 , Joshua M. Hardy 1 2 , Andrew P. Thompson 1 2 , Hanadi Hoblos 1 2 , Michael J. Roy 1 2 , Tracy L. Putoczki 1 2 , Isabelle S. Lucet 1 2
  1. WEHI - Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
  2. Department of Medical Biology , University of Melbourne , Parkville , VIC, Australia

Doublecortin-like kinase 1 (DCLK1) is a pro-oncogenic target with kinase activity and microtubule-associated functions. Upregulation of DCLK1 has been implicated in various aggressive cancers, including gastric cancer, colorectal cancer, brain cancer, and pancreatic ductal adenocarcinoma (PDAC), promoting tumour aggressiveness, invasion, metastasis and chemoresistance[1]. The role of DCLK1 in tumorigenesis is complicated by differential expression of distinct and multi-functional protein isoforms across disease settings[2, 3]. We describe these confounding factors as a “Double Trouble” scenario, complicating research efforts to understand its contribution to cancer. The two in-tandem N-terminal doublecortin domains (DC) of DCLK1 regulate microtubule dynamics, while the C-terminal serine/threonine kinase domain, along with its auto-inhibitory C-terminal tail, modulate kinase activity[4]. Additionally, alternative splicing and promoter usage generate four distinct DCLK1 isoforms that differ in the length of their regulatory C-terminal tails and the presence (isoform 1-2) or absence (isoform 3-4) of the DC domains. Due to the lack of isoform-specific tools, the complex relationship between DCLK1 isoforms and oncogenesis has been largely overlooked in the current literature.

My project aims to comprehensively characterise DCLK1 isoforms in aggressive cancers like PDAC to guide the development of isoform-centric diagnostic markers and precision therapies. I will develop biological tools to specifically target DCLK1 isoforms through phage display biopanning against a proprietary human antibody library. These tools will be used to profile DCLK1 isoform expression in cancer cell lines and patient samples, correlating expression levels with tumour phenotypes to clarify their role in tumorigenesis. Additionally, I will employ advanced imaging techniques, such as lattice light sheet microscopy and cryo-electron microscopy, to investigate the functional and structural attributes of these isoforms, supporting the development of selective biomarkers and precision therapies for aggressive cancers.

 

  1. Ye, L., et al., DCLK1 and its oncogenic functions: A promising therapeutic target for cancers. Life Sci, 2024. 336: p. 122294.
  2. O'Connell, M.R., et al., Epigenetic changes and alternate promoter usage by human colon cancers for expressing DCLK1-isoforms: Clinical Implications. Sci Rep, 2015. 5: p. 14983.
  3. Qu, D., et al., Overexpression of DCLK1-AL Increases Tumor Cell Invasion, Drug Resistance, and KRAS Activation and Can Be Targeted to Inhibit Tumorigenesis in Pancreatic Cancer. J Oncol, 2019. 2019: p. 6402925.
  4. Carli, A.L.E., et al., Structure-Guided Prediction of the Functional Impact of DCLK1 Mutations on Tumorigenesis. Biomedicines, 2023. 11(3).