Novel selective binders for gastrointestinal DCLK1 isoforms

Doublecortin-like kinase 1 (DCLK1) is a microtubule-associated protein kinase that plays a critical role in the maintenance of gastrointestinal (GI) epithelial integrity and regeneration. Emerging evidence highlights the functional divergence of its isoforms-particularly the long and short forms-which are differentially expressed during homeostasis and disease. In healthy GI tissue, DCLK1-long primarily maintains stem cell quiescence and epithelial repair. Conversely, DCLK1-short is markedly elevated in several GI malignancies and is associated with oncogenic transformation, invasion, and poor prognosis. We are investigating compounds that modulate DCLK1 isoforms to mitigate irradiation-induced gastrointestinal acute radiation syndrome (GI-ARS). Our research demonstrates that 2-deoxyglucose (2DG) and its non-metabolizable analogue differentially regulate crypt and colonoid growth in ex vivo systems. Treatment with 2DG results in selective suppression of the DCLK1-short isoform while sparing or modestly enhancing the DCLK1-long variant, suggesting a potential therapeutic window for targeting tumor-specific isoform expression. To further identify molecular binders capable of modulating DCLK1 activity, we employed a structure-based virtual screening approach using a focused library of 100,000 small molecules. High-throughput in silico docking enabled the identification of several high-affinity lead compounds with potential isoform-selective binding. The strategy of small-molecule screening offers a promising approach for selective intervention in DCLK1-driven pathologies in GI tissue repair.