Metastasis underlies most colorectal cancer (CRC)-related deaths, yet its molecular drivers remain incompletely characterized. This study aims to provide novel insights into the mechanisms underlying CRC metastasis through integrated multiomics and experimental validation. Malignant epithelial cell subpopulations and key regulators of metastatic transition were identified through copy number variation inference and pseudotime trajectory analysis from CRC scRNA-seq data. Dual-luciferase reporter, chromatin immunoprecipitation, and functional studies were used for mechanistic validation in vitro. Tumor growth and metastatic capacity in vivo were evaluated using subcutaneous xenograft and tail vein injection-induced metastasis models. Clinical samples were analyzed to investigate the expression patterns of ASCL2 and TDGF1 during CRC clinical progression. ScRNA-seq revealed a malignant tumor cell subpopulation undergoing differentiation toward metastasis. Pseudotime trajectory analysis revealed the transcription factor ASCL2 as a key regulator of metastatic transition, with its expression increasing during fate commitment from primary to metastatic states. ASCL2 directly binds the TDGF1 promoter to activate its transcription. Functional studies demonstrated that the ASCL2-TDGF1 axis drives the progression of malignant phenotype and metastasis progression in CRC. TDGF1 depletion significantly attenuated the ASCL2 overexpression-induced malignant phenotypes in vitro and xenograft tumor growth and metastasis in vivo. Analysis of clinical samples indicated that expression levels of ASCL2 and TDGF1 were progressively upregulated during CRC progression. The ASCL2-TDGF1 cascade is a master regulator of CRC metastasis. ASCL2 drives CRC metastasis through direct TDGF1 transcriptional activation, highlighting the pivotal role of TDGF1 as the critical executor of ASCL2-driven metastasis in CRC.
Li et al. (2026) studied this question.