Single-cell RNA sequencing reveals that TAF7 promotes colorectal cancer stemness by targeting SOX2.

Abstract

Background: Cancer cell stemness plays a decisive role in tumor metastasis and recurrence. TATA-box binding protein-associated factor 7 (TAF7), which is highly expressed in multiple cancers and critical for metastasis, has not been clearly linked to stemness characteristics in colorectal cancer (CRC). Therefore, this study aimed to investigate the role of TAF7 in CRC stemness.

Methods: Differential gene expression and associated signaling pathways were screened using single-cell transcriptomic data from CRC and adjacent normal tissues obtained from the GEO database and validated in CRC cells. A TAF7-knockdown CRC cell line was established to assess the impact of TAF7 on tumor cell stemness. The molecular mechanism of TAF7 in regulating CRC stemness was explored through bioinformatics analysis combined with chromatin immunoprecipitation and dual-luciferase reporter assays and validated by rescue experiments. Finally, a CRC xenograft mouse model was established to examine the effect of targeting TAF7 on tumor cell stemness and epithelial-mesenchymal transition (EMT).

Results: Re-analysis of single-cell transcriptomics data identified a TAF7⁺ epithelial cell subpopulation that is highly expressed in CRC and characteristically expresses the stemness marker SOX2. In vitro experiments demonstrated that high TAF7 expression promotes CRC stemness, primarily by enhancing the transcriptional activation of SOX2. Rescue experiments confirmed that targeting the TAF7/SOX2 axis suppresses CRC stemness and EMT. Furthermore, in vivo experiments showed that TAF7 targeting inhibits tumor growth and CRC stemness in mice.

Conclusion: Our integrated single-cell transcriptomic and functional analyses reveal that TAF7 promotes CRC stemness and EMT progression via transcriptional activation of the stemness marker SOX2.