β1, 4-N-acetylgalactosaminyltransferase III modulates cancer stemness through EGFR signaling pathway in colon cancer cells

Abstract

Cancer stem cells are cancer cells characterized with tumor initiating capacity. β1,4-N-acetylgalactosaminyltransferase III (B4GALNT3) synthesizes GalNAcβ1-4GlcNAc (LacdiNAc) which contributes to self-renewal of mouse embryonic stem cells. We previously showed that B4GALNT3 overexpression enhances colon cancer cell malignant phenotypes in vitro and in vivo. However, the role of B4GALNT3 in cancer stemness remains unclear. We found that B4GALNT3 expression was positively correlated with advanced stages and poor survival in colorectal cancer patients. Knockdown of B4GALNT3 using small interfering (si) RNAs in colon cancer cell lines (HCT116, SW480, HCT15, and HT29 cells) decreased sphere formation and the expression of stem cell markers, OCT4 and NANOG. The expression of B4GALNT3 was upregulated in colonospheres. Interestingly, we found that B4GALNT3 primarily modified N-glycans of EGFR with LacdiNAc by Wisteria floribunda agglutinin (WFA) pull down assays. B4GALNT3 knockdown suppressed EGF-induced phosphorylation of EGFR and its downstream signaling molecules. Furthermore, EGF-induced degradation of EGFR was facilitated. In addition, EGF-induced migration and invasion were significantly suppressed by B4GALNT3 knockdown. Taken together, these data suggest B4GALNT3 regulates cancer stemness and the invasive properties of colon cancer cells through modifying EGFR glycosylation and signaling. Our results provide novel insights into the role of LacdiNAc in colorectal cancer development.

Trefoil Factor Family Domains Represent Highly Efficient Conformational Determinants for N-Linked N,N′-di-N-acetyllactosediamine (LacdiNAc) Synthesis

“…␤4-GalNAc-T3 was shown to predict a favorable prognosis for neuroblastoma and to suppress the malignant phenotype via decreasing ␤1-integrin signaling (40). In the same context the enzyme was demonstrated to regulate cancer stemness and the invasive properties of colon cancer cells through modifying EGFR glycosylation and signaling (41).…”

C1GALT1 Seems to Promote In Vitro Disease Progression in Ovarian Cancer

“…The sphere formation has been used to enrich cells that exhibit stem-cell properties as free-floating spheres and identify cells that exhibit self-renewal capacity, 25 and thus, we used this assay to quantify whether the expression of C1GALT1 altered the number of spheres in ovarian cancer cells. As shown in Figure 5A, knockdown of C1GALT1 showed significant suppressive effect on sphere forming ability of ES-2 and OVTW59-p4 cells.…”

Molecular Basis for Recognition of the Cancer Glycobiomarker, LacdiNAc (GalNAc[β1→4]GlcNAc), by Wisteria floribunda Agglutinin

“…The GalNAc transferase ␤4GalNAc-T3 is primarily responsible for its biosynthesis (21). Significantly, glycoproteins expressing terminal LacdiNAc appear to become elevated in a variety of human cancers, including prostate, lung, ovarian, colon, and liver cancers (6,8,9,(22)(23)(24)(25). The tissue-specific expression of the LacdiNAc is a potent diagnostic marker for specific human cancers (23), and several recent studies have promoted the use of WFA for detection of LacdiNAc or terminal GalNAc overexpressed during cancer progression and growth (26 -33).…”