Transcription factor FOXD1 and miRNA-204-5p play a major role in B4GALNT2 downregulation in colon cancer.

The β1,4-N-acetylgalactosaminyltransferase 2 (B4GALNT2) which synthesizes the histo-blood group antigen Sd is highly expressed by normal colon, but it is dramatically down-regulated in colorectal cancer (CRC). High B4GALNT2 expression in CRC tissues is a marker of longer survival. The molecular bases of B4GALNT2 inhibition in CRC are largely obscure.

Salmonid polysialyltransferases to generate a variety of sialic acid polymers.

The human polysialyltransferases ST8Sia II and ST8Sia IV catalyze the transfer of several Neu5Ac residues onto glycoproteins forming homopolymers with essential roles during different physiological processes. In salmonids, heterogeneous set of sialic acids polymers have been described in ovary and on eggs cell surface and three genes st8sia4, st8sia2-r1 and st8sia2-r2 were identified that could be implicated in these heteropolymers. The three polysialyltransferases from the salmonid Coregonus maraena were cloned, recombinantly expressed in HEK293 cells and the ST8Sia IV was biochemically characterized.

-Glycan on the Non-Consensus N-X-C Glycosylation Site Impacts Activity, Stability, and Localization of the Sd Synthase B4GALNT2.

The Sd carbohydrate epitope and its biosynthetic B4GALNT2 enzyme are expressed in the healthy colon and down-regulated to variable extents in colon cancer. The human gene drives the expression of a long and a short protein isoform (LF-B4GALNT2 and SF-B4GALNT2) sharing identical transmembrane and luminal domains. Both isoforms are trans-Golgi proteins and the LF-B4GALNT2 also localizes to post-Golgi vesicles thanks to its extended cytoplasmic tail.

Analysis of the proximal promoter of the human colon-specific B4GALNT2 (Sd synthase) gene: B4GALNT2 is transcriptionally regulated by ETS1.

Background: The Sd antigen and corresponding biosynthetic enzyme B4GALNT2 are primarily expressed in normal colonic mucosa and are down-regulated to a variable degree in colon cancer tissues. Although their expression profile is well studied, little is known about the underlying regulatory mechanisms.

Methods: To clarify the molecular basis of Sd expression in the human gastrointestinal tract, we investigated the transcriptional regulation of the human B4GALNT2 gene.

B4GALNT2 Controls Sd and SLe Antigen Biosynthesis in Healthy and Cancer Human Colon.

The Sd carbohydrate antigen and the corresponding biosynthetic enzyme B4GALNT2 are primarily expressed in human normal colonic mucosa and are down-regulated to variable degrees in colon cancer. On the other hand, the tumor associated antigen SLe is not detected in the healthy colon and is upregulated in colon cancer. High level of B4GALNT2 gene expression appears to be a good marker of prognosis in colon cancer; however, the molecular mechanisms regulating these carbohydrate antigens' expression are still poorly understood.