Abstract Distant metastasis is the leading cause of mortality in patients with advanced colorectal cancer (CRC), underscoring the need for novel therapeutic targets. Although cancer stem cells are thought to contribute to metastatic progression, the regulatory mechanisms governing CRC stemness remain incompletely understood. Using an autochthonous metastatic mouse model harboring sporadic mutations in Ctnnb1, Kras, Trp53, and Smad4 genes (CKPS mice), together with CRC cell lines derived from these mice (CKPS cells), we previously demonstrated that the cAMP/PKA/CREB signaling promotes CRC stemness and metastasis partly by inducing the stemness markers ALCAM (CD166) and PROM1 (CD133).To further elucidate pathways sustaining CRC stemness, we performed a compound screen of approximately 500 agents using CKPS spheroid cultures. Among them, QNZ—an inhibitor reported to target NF-κB—significantly downregulated ALCAM and PROM1 and markedly suppressed liver metastasis. Unexpectedly, genetic analysis revealed that these effects were independent of canonical NF-κB signaling. Integrating proteomic and RNA-seq analyses, we identified transcription factors GRHL2 and SOX9 as candidates linking spheroid-induced transcriptional changes to QNZ responsiveness. Grhl2 knockout reduced ALCAM expression in CKPS spheroid cultures and impaired liver metastasis. On the other hand, Sox9 knockout or Ctnnb1 knockdown attenuated PROM1 induction in CKPS spheroids, consistent with SOX9 functioning downstream of Wnt/β-catenin signaling.Collectively, these findings reveal the involvement of multiple pathways—including GRHL2- and Wnt/SOX9-mediated regulation—in maintaining CRC stemness and metastatic potential, providing new insights into therapeutic vulnerabilities of metastatic CRC. Citation Format: Teruaki Fujishita, Yanqing Niu, Masahiro Aoki. Identification of key pathways regulating colorectal cancer stemness and metastasis through compound screening abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6099.
Fujishita et al. (Fri,) studied this question.