Sulfation of O-glycans on mucin-type proteins from serous ovarian epithelial tumors (original) (raw)
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Carbohydrate Research, 2006
Carbohydrate chains of cancer glycoprotein antigens contain major outer changes dictated by tissue-specific regulation of glycosyltransferase genes, the availability of sugar nucleotides, and competition between enzymes for acceptor intermediates during glycan elongation. However, it is evident from recent studies with recombinant mucin probes that the final glycosylation profiles of mucin glycoproteins are mainly determined by the cellular repertoire of glycosyltransferases. Hence, we examined various cancer cell lines for the levels of fucosyl-, b-galactosyl, b-N-acetylgalactosaminyl-, sialyl-, and sulfotransferase activities that generate the outer ends of the oligosaccharide chains. We have identified glycosyltransferases activities at the levels that would give rise to O-glycan chains as reported by others in breast cancer cell lines, T47D, ZR75-1, MCF-7, and MDA-MB-231. Most breast cancer cells express Gal-3-O-sulfotransferase specific for T-hapten Galb1!3GalNAca-, whereas the enzyme from colon cancer cells exhibits a vast preference for the Galb1,4GlcNAc terminal unit in O-glycans. We also studied ovarian cancer cells SW626 and PA-1 and hepatic cancer cells HepG 2. Our studies show that a1,2-L L-fucosyl-T, a(2,3) sialyl-T, and 3-O-Sulfo-T capable of acting on the mucin core 2 tetrasaccharide, Galb1,4GlcNAcb1,6(Galb1,3)GalNAca-, can also act on the Globo H antigen backbone, Galb1, 3GalNAcb1,3Gala-, suggesting the existence of unique carbohydrate moieties in certain cancer-associated glycolipids. Briefly, our study indicates the following: (i) 3 0-Sulfo-T-hapten has an apparent relationship to the tumorigenic potential of breast cancer cells; (ii) the 3 0-sulfo Lewis x , the 3-O-sulfo-Globo unit, and the 3-fucosylchitobiose core could be uniquely associated with colon cancer cells; (iii) synthesis of a polylactosamine chain and T-hapten are favorable in ovarian cancer cells due to negligible sialyltransferase activities; and (iv) a 6 0-sialyl LacNAc unit and 3 0-sialyl T-hapten appear to be prevalent structures in hepatic cancer cell glycans. Thus, it is apparent that different cancer cells are expressing unique glycan epitopes, which could be novel targets for cancer diagnosis and treatment.
Glycoconjugate journal, 1999
We found earlier in human breast and colon tumors, an augmented level of Gal : 3-O-sulfotransferase activities showing, respectively, an acceptor preference to blood group T-hapten (Group A enzymes) or Galbeta1,4GlcNAc (Group B enzymes) on the mucin Core 2 structure [Chandrasekaran EV, Jain RK, Vig R, and Matta KL (1997) Glycobiology 7: 753-68]. The present study reports these enzyme activities in human tumor cell lines and additional tumor specimens. The human colon tumor epithelial cell lines, akin to their parent tumors, express Group B enzyme activity. The acceptor specificity and kinetic properties, such as divalent metal ion activation and pH dependent activity profile, of the colon cancer line LS180 enzyme activity are identical to those of colon tissue specimens. Consistent with breast tumor specimens, the Group A enzyme activity is present in human breast tumor epithelial cell lines, with some exceptions. The Gal : 3-O-sulfotransferases show specific binding to Aleuria aura...
Presence and characterization of glycolipid sulfotransferase in human cancer serum
European Journal of Biochemistry, 1990
Sulfotransferase, which catalyzes sulfation of the carbohydrate of galactosylceramide (GalCer) and is localised in the Golgi membrane of cells, was assayed for activity in human serum. To do this, an organic solvent was added to the incubated reaction mixture containing GalCer as an acceptor and phosphoadenosine p h~s p h o [~ sulfate as a donor of sulfate to dissociate the synthesized sulfolipid from serum protein. This was followed by isolation of the sulfolipid on an anion-exchange column. Through this procedure, human serum was found to contain sulfotransferase activity. The serum enzyme was activated by Mn2+. K, values of the enzyme for GalCer and 'active sulfate' were 4.6 pM and 5.2 pM, respectively. The enzyme activity was assayed in sera of cancer patients. The serum activity (mean 5 SE, 0.27 0.027 pmol. pl-'. h-l) in renal cell carcinoma patients, whose activity has been demonstrated to be elevated, was significantly (P < 0.005) increased compared to that of the normal control (mean SE, 0.18 f 0.0014 pmol. pl-'. h-') and of other urological tumors examined. Cerebroside sulfotransferase transfers a sulfate group from 3'-phosphoadenosine 5'-phosphosulfate (PAdoPS) to C3 of the galactose moiety of GalCer to form a sulfolipid [l]. The sulfotransferase activity was demonstrated in particulate fractions from brains of rat [2-41, sheep [5] and mouse [6,7] and in the Golgi apparatus from rat brain [8] and rat kidneys [9-111. The localization of cerebroside sulfotransferase is similar to that of glycosaminoglycan sulfotransferases [12] and tyrosylprotein sulfotransferase [13], but different from that of sulfotransferases acting on aryl compounds, hydroxysteroids, estrogens, and bile acids [14], all ofwhich are found in cytosol. Glycosyltransferase activity catalyzing glycolipid synthesis is, in general, hardly detectable in body fluids and no glycolipid sulfotransferase activity has been demonstrated in them. The cerebroside sulfotransferase was solubilized from rat brains [3, 15, 161 and from rat kidney [I I] and its enzymatic properties characterized. As to substrate specificity, the sulfotransferase catalyzed the sulfation not only of GalCer but also of LacCer [15] and galactosyldiacylglycerol[17]. Recently, Tennekoon et al. [18] highly purified the sulfotransferase from rat kidney; they demonstrated the presence of lipids bound to the enzyme, consisting of cholesterol and phospholipid, which irreversibly affected the enzyme activity. The sulfotransferase activity of partially delipidated microsomes from mouse brain was modulated by the microsomal lipids in an age-dependent manner [7]. These observations suggest that the enzyme activity is modulated by the surrounding lipid. In our previous studies on human cancer tissues, the sulfolipid increased in human lung adenocarcinoma [ 191, gas
O-glycan biosynthesis in human colorectal adenoma cells during progression to cancer
European Journal of Biochemistry, 1994
A human colonic adenoma cell line PCIAA derived from a familial polyposis coli patient was passaged in culture to form an intermediate premalignant clonogenic variant AA/Cl and, upon treatment with differentiating and carcinogenic agents, a cell line AA/Cl/SB10 which is tumourigenic in nude mice. These three mucin-secreting cell lines have been used as a model to study the changes in 0-glycan biosynthesis during the progression to cancer. Several glycosyltransferases involved in the synthesis, elongation and termination of the common 0-glycan core structures were found to decrease in the progression sequence towards adenocarcinoma. Higher activity of a number of enzymes was seen in the intermediate cell line. 0-glycan biosynthesis in the original PCIAA cell line was closest to the normal human colonic phenotype, since all four common mucin 0-glycan cores and their extended structures could be synthesized; core 3 fl-GlcNAc-transferase and a6sialyltransferase acting on GalNAc-mucin were still detectable and core 2 P6-GlcNAc-transferase activity was accompanied by core 4 and I P6-GlcNAc-transferase activities. During progression towards adenocarcinoma, the expression of a6-sialyltransferase, core 3 fl-GlcNAc-transferase, core 4 and I P6-GlcNAc-transferases were turned off. Using monoclonal antibodies, Tn antigen, sialyl-Tn antigen, 0-acetyl-sialomucin and sialyl-Lea determinants were not detected in secreted or cellular mucin isolated from any of the cell lines. The exposure of MUCl epitopes was seen in the malignant line, whereas sialyl-Le" determinants were found only in the premalignant PC/AA line. Sulfotransferase activities using core 1 substrate, GalPl-3GalNAca-benzy1, were high in PCIAA cells and progressively decreased upon development to adenocarcinoma, and this decrease correlated with mucin sulfation. In summary, the synthesis of less abundant, sialylated, fucosylated and extended, unbranched core 1 structures should be facilitated in the malignant cells. This is the first report of glycosyltransferase changes in human premalignant cells developing to tumourigenic cells. The data demonstrate that these cell lines are an excellent model to study the changes and regulation of mucin oligosaccharide biosynthesis during progression to cancer. Fax: +1 416 813 5022. Abbreviations. Bzl, benzyl; PAdoPS, 3'-phosphoadenosine 5'phosphosulfate ; Np, p-nitrophenyl.
Changes in composition and sulfation patterns of glycoaminoglycans in renal cell carcinoma
Glycoconjugate journal, 2015
Glycosaminoglycans (GAGs) are heterogeneous, linear, highly charged, anionic polysaccharides consisting of repeating disaccharides units. GAGs have some biological significance in cancer progression (invasion and metastasis) and cell signaling. In different cancer types, GAGs undergo specific structural changes. In the present study, in depth investigation of changes in sulfation pattern and composition of GAGs, heparan sulfate (HS)/heparin (HP), chondroitin sulfate (CS)/dermatan sulfate and hyaluronan (HA) in normal renal tissue (NRT) and renal cell carcinoma tissue (RCCT) were evaluated. The statistical evaluation showed that alteration of the HS (HSNRT = 415.1 ± 115.3; HSRCCT = 277.5 ± 134.3), and CS (CSNRT = 35.3 ± 12.3; CSRCCT = 166.7 ± 108.8) amounts (in ng/mg dry tissue) were statistically significant (p < 0.05). Sulfation pattern in NRT and RCCT was evaluated to reveal disaccharide profiles. Statistical analyses showed that RCCT samples contain significantly increased amo...
PLOS ONE, 2015
Background Mucins are heavily O-glycosylated proteins where the glycosylation has been shown to play an important role in cancer. Normal epithelial ovarian cells do not express secreted mucins, but their abnormal expression has previously been described in epithelial ovarian cancer and may relate to tumor formation and progression. The cyst fluids were shown to be a rich source for acidic glycoproteins. The study of these proteins can potentially lead to the identification of more effective biomarkers for ovarian cancer.
O-linked mucin-type glycosylation in breast cancer
Biochemical Society Transactions, 2018
Changes in mucin-type O-linked glycosylation are seen in over 90% of breast cancers where increased sialylation is often observed and a change from branched glycans to linear glycans is often seen. There are many mechanisms involved including increased/altered expression of glycosyltransferases and relocalisation to the endoplasmic reticulum of the enzymes responsible for the addition of the first sugar, N-acetyl-d-galactosamine. It is now becoming clear that these changes can contribute to tumour growth and progression by modulating the micro-environment through glycan-sensing lectins expressed on immune cells, by modulating interactions with tumour surface receptors and by binding to selectins. The understanding of how changes in mucin-type O-linked glycosylation influence tumour growth and progression reveals new potential targets for therapeutic intervention in the treatment of breast cancer.
Journal of Biological Chemistry, 2004
Sulfated glycoconjugates regulate biological processes such as cell adhesion and cancer metastasis. We examined the acceptor specificities and kinetic properties of three cloned Gal:3-O-sulfotransferases (Gal3STs) ST-2, ST-3, and ST-4 along with a purified Gal3ST from colon carcinoma LS180 cells. Gal3ST-2 was the dominant Gal3ST in LS180. While the mucin core-2 structure Gal1,4GlcNAc1,6(3-O-MeGal1,3)GalNAc␣-O-Bn (where Bn is benzyl) and the disaccharide Gal1,4GlcNAc served as high affinity acceptors for Gal3ST-2 and Gal3ST-3, 3-O-MeGal1,4GlcNAc1,-6(Gal1,3)GalNAc␣-O-Bn and Gal1,3GalNAc␣-O-Al (where Al is allyl) were efficient acceptors for Gal3ST-4. The activities of Gal3ST-2 and Gal3ST-3 could be distinguished with the Globo H precursor (Gal1,3GalNAc1,3Gal␣-O-Me) and fetuin triantennary asialoglycopeptide. Gal3ST-2 acted efficiently on the former, while Gal3ST-3 showed preference for the latter. Gal3ST-4 also acted on the Globo H precursor but not the glycopeptide. In support of the specificity, Gal3ST-2 activity toward the Gal1,4GlcNAc unit on mucin core-2 as well as the Globo H precursor could be inhibited competitively by Gal1,4GlcNAc1,6(3-O-sulfoGal1,3)GalNAc␣-O-Bn but not 3-O-sulfoGal1,-4GlcNAc1,6(Gal1,3)GalNAc␣-O-Bn. Remarkably these sulfotransferases were uniquely specific for sulfated substrates: Gal3ST-3 utilized Gal1,4(6-O-sulfo)-GlcNAc-O-Al as acceptor, Gal3ST-2 acted efficiently on Gal1,3(6-O-sulfo)GlcNAc-O-Al, and Gal3ST-4 acted efficiently on Gal1,3(6-O-sulfo)GalNAc␣-O-Al. Mg 2؉ , Mn 2؉ , and Ca 2؉ stimulated the activities of Gal3ST-2, whereas only Mg 2؉ augmented Gal3ST-3 activity. Divalent cations did not stimulate Gal3ST-4, although inhibition was noted at high Mn 2؉ concentrations. The fine substrate specificities of Gal3STs indicate a distinct physiological role for each enzyme.