β1,4-Galactosyltransferase V Modulates Breast Cancer Stem Cells through Wnt/β-catenin Signaling Pathway.

Abstract

PURPOSE:

Breast cancer stem cells (BCSCs) contribute to the initiation, development, and recurrence of breast carcinomas. β1,4-Galactosyltransferase V (B4GalT5), which catalyzes the addition of galactose to GlcNAcβ1-4Man of N-glycans, is involved in embryogenesis. However, its role in the modulation of BCSCs remains unknown.

MATERIALS AND METHODS:

The relationship between B4GalT5 and breast cancer stemness was investigated by online clinical databases and immunohistochemistry analysis. Mammosphere formation, fluorescence-activated cell sorting (FACS), and in-vivo assays were used to evaluate B4GalT5 expression in BCSCs and its effect on BCSCs. B4GalT5 regulation of Wnt/β-catenin signaling was examined by immunofluorescence and Ricinus communis agglutinin I pull-down assays. Cell surface biotinylation and FACS assays were performed to assess the association of cell surface B4GalT5 and BCSCs.

RESULTS:

B4GalT5, but not other B4GalTs, was highly correlated with BCSC markers and poor prognosis. B4GalT5 significantly increased the stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) and promoted the production of CD44+CD24-/low cells and the formation of mammospheres. Furthermore, B4GalT5 overexpression resulted in dramatic tumor growth in vivo. Mechanistically, B4GalT5 modified and protected Frizzled-1 from degradation via the lysosomal pathway, promoting Wnt/β-catenin signaling which was hyperactivated in BCSCs. B4GalT5, located on the surface of a small subset of breast carcinoma cells, was not responsible for the stemness of BCSCs.

CONCLUSION:

B4GalT5 modulates the stemness of breast cancer through glycosylation modification to stabilize Frizzled-1 and activate Wnt/β-catenin signaling independent of its cell surface location. Our studies highlight a previously unknown role of B4GalT5 in regulating the stemness of breast cancer and provide a potential drug target for anticancer drug development.

• Authors: Wei Tang, Meng Li, Xin Qi, Jing Li
• Journal: Cancer research and treatment (Cancer Res Treat) Vol. 52 Issue 4 Pg. 1084-1102 (Oct 2020) ISSN: 2005-9256 [Electronic] Korea (South)
• PMID: 32599982 (Publication Type: Journal Article)

Chemical References

• FZD1 protein, human
• Frizzled Receptors
• Aldehyde Dehydrogenase 1 Family
• ALDH1A1 protein, human
• Retinal Dehydrogenase
• B4GALT5 protein, human
• Galactosyltransferases

Topics

• Aldehyde Dehydrogenase 1 Family (analysis, metabolism)
• Animals
• Breast (pathology)
• Breast Neoplasms (pathology)
• Carcinoma, Ductal, Breast (pathology)
• Cell Line, Tumor
• Cell Proliferation
• Datasets as Topic
• Female
• Frizzled Receptors (metabolism)
• Galactosyltransferases (genetics, metabolism)
• Gene Knockdown Techniques
• Humans
• Mice
• Neoplastic Stem Cells (pathology)
• Proteolysis
• Retinal Dehydrogenase (analysis, metabolism)
• Tissue Array Analysis
• Wnt Signaling Pathway
• Xenograft Model Antitumor Assays