FUT9-Driven Programming of Colon Cancer Cells towards a Stem Cell-Like State

SIMPLE SUMMARY: Aberrant glycosylation, for instance heightened expression of fucosylated structures, is a frequent feature observed in tumor cells. Our paper outlines the role of aberrant fucosylation by the Fucosyltransferase 9 (FUT9) as a potent reprogramming factor marking the acquisition of a stem-like state both by murine and human colon cancer cells. Importantly, our study reinforces the implication of aberrant fucosylation in promoting tumor growth and resistance to chemotherapy in the context of colon cancer. ABSTRACT: Cancer stem cells (CSCs) are located in dedicated niches, where they remain inert to chemotherapeutic drugs and drive metastasis. Although plasticity in the CSC pool is well appreciated, the molecular mechanisms implicated in the regulation of cancer stemness are still elusive. Here, we define a fucosylation-dependent reprogramming of colon cancer cells towards a stem cell-like phenotype and function. De novo transcriptional activation of Fut9 in the murine colon adenocarcinoma cell line, MC38, followed by RNA seq-based regulon analysis, revealed major gene regulatory networks related to stemness. Lewis(x), Sox2, ALDH and CD44 expression, tumorsphere formation, resistance to 5-FU treatment and in vivo tumor growth were increased in FUT9-expressing MC38 cells compared to the control cells. Likewise, human CRC cell lines highly expressing FUT9 displayed phenotypic features of CSCs, which were significantly impaired upon FUT9 knock-out. Finally, in primary CRC FUT9(+) tumor cells pathways related to cancer stemness were enriched, providing a clinically meaningful annotation of the complicity of FUT9 in stemness regulation and may open new avenues for therapeutic intervention.