Calreticulin activates β1 integrin via fucosylation by fucosyltransferase 1 in J82 human bladder cancer cells

Abstract

Fucosylation regulates various pathological events in cells. We reported that different levels of CRT (calreticulin) affect the cell adhesion and metastasis of bladder cancer. However, the precise mechanism of tumour metastasis regulated by CRT remains unclear. Using a DNA array, we identified FUT1 (fucosyltransferase 1) as a gene regulated by CRT expression levels. CRT regulated cell adhesion through α1,2-linked fucosylation of β1 integrin and this modification was catalysed by FUT1. To clarify the roles for FUT1 in bladder cancer, we transfected the human FUT1 gene into CRT-RNAi stable cell lines. FUT1 overexpression in CRT-RNAi cells resulted in increased levels of β1 integrin fucosylation and rescued cell adhesion to type-I collagen. Treatment with UEA-1 (Ulex europaeus agglutinin-1), a lectin that recognizes FUT1-modified glycosylation structures, did not affect cell adhesion. In contrast, a FUT1-specific fucosidase diminished the activation of β1 integrin. These results indicated that α1,2-fucosylation of β1 integrin was not involved in integrin-collagen interaction, but promoted β1 integrin activation. Moreover, we demonstrated that CRT regulated FUT1 mRNA degradation at the 3'-UTR. In conclusion, the results of the present study suggest that CRT stabilized FUT1 mRNA, thereby leading to an increase in fucosylation of β1 integrin. Furthermore, increased fucosylation levels activate β1 integrin, rather than directly modifying the integrin-binding sites.

Site-Specific Fucosylation Analysis Identifying Glycoproteins Associated with Aggressive Prostate Cancer Cell Lines Using Tandem Affinity Enrichments of Intact Glycopeptides Followed by Mass Spectrometry

“…66 Chang et al showed that the increase in fucosylation of integrin β 1 could activate integrin β 1 in J82 human bladder cancer cells. 67 It has also been reported that core fucosylation is essential for the functions of integrin α 3 β 1-mediated cell migration and signaling, wherein deletion of core fucosylation on integrin α 3 β 1 could down-regulates its function. 68 These observations are consistent with our previous report that FUT8 overexpression in LNCaP cells increased Pca cell migration, while loss of FUT8 in PC3 cells decreased cell motility 54 and our results in this study indicate this could be integrin-mediated.…”

Functional Roles of Calreticulin in Cancer Biology

“…According to our latest observation, one critical role of CRT which regulates integrin activation is through modifying α 1, 2-linkaged glycomic status on β 1-integrin. Mechanistic investigation demonstrated that CRT controlled the mRNA stability of an important enzyme, fucosyltransferase 1 (FUT1), which catalyzes α 1, 2-linked fucosylation on β 1-integrin and subsequently promotes β 1-integrin activities [ 106 ]. These results not only clarify the biological mechanism for CRT regulating integrin functions in cell adhesion process but also provide a new possible strategy for inhibition of cancer metastasis.…”

Synthesis and cell-selective antitumor properties of amino acid conjugated tumor-associated carbohydrate antigen-coated gold nanoparticles

“…TACA expression can be a result of changes in several different steps in the glycoprocessing machinery, including increased/decreased sialylation 14–24 or fucosylation 25–29 , increased N-linked glycan branching, altered O-linked glycolipid (ganglioside) compositions 30–34 and truncated mucin-type O-glycans. 16,35–50 These structures, in part, may modify the physical and chemical properties of the tumor cell, leading to altered cell adhesion and signal transduction, often resulting in enhanced aggressiveness and metastatic potential.…”