ABH and Lewis histo-blood group antigens in cancer

AB0 blood group and prognosis in patients with pancreatic cancer

BACKGROUND

Although blood group 0 is associated with a reduced risk of pancreatic cancer, little is known about the role of AB0 blood group antigens in disease progression. We assessed the prognostic relevance of AB0 blood status in a large cohort of patients with resected pancreatic cancer.

METHODS

A total of 627 patients, who underwent resection for pancreatic ductal adenocarcinoma between October 2001 and December 2008 were enrolled. The relationship between AB0 blood group status and outcome was analyzed using univariate and multivariate Cox regression analyses.

RESULTS

In patients with pancreatic cancer the incidence of blood group 0 (31%) was lower compared to 13.044 patients without pancreatic cancer (38%) (p = 0.0005). There were no significant differences in clinicopathologic characteristics among patients with different AB0 blood groups. The 3-year and 5-year overall survival rates were 29% and 14%. On univariate analysis AB0 blood group status did not correlate with survival (p = 0.39). Multivariate analysis, however, revealed a favorable and independent impact of blood group 0 on survival (Hazard ratio 0.78; 95% confidence interval 0.62 - 0.99; p = 0.037).

CONCLUSION

AB0 blood group status is associated independently with the prognosis of patients with resected pancreatic cancer.

Association of type O blood with pancreatic neuroendocrine tumors in Von Hippel-Lindau syndrome

BACKGROUND

ABO blood type antigens are expressed not only on human red blood cells, but also throughout the gastrointestinal tract and in normal pancreatic tissue. Previous studies have identified an association between ABO blood type and various malignancies. We analyzed the association of ABO blood type with pancreatic neuroendocrine tumors (PNETs) in a high-risk cohort of patients with Von Hippel-Lindau (VHL) syndrome.

METHODS

A retrospective review was performed of 798 patients with VHL syndrome. Blood type was confirmed for 181 patients. Fisher's exact test and Mehta's modification to Fisher's exact test were used to test for an association between ABO blood type and manifestations of VHL syndrome.

RESULTS

We found a strong trend for association between O blood type and pancreatic disease manifestation in patients with VHL syndrome (P = 0.047). More importantly, there was a significant association of O blood type with solid pancreatic lesions consistent with PNETs (P = 0.0084). Patients with solid pancreatic lesions who met criteria for surgical resection at the National Institutes of Health also had a higher rate of O blood type than those who did not require surgery (P = 0.051).

CONCLUSIONS

Our findings suggest an association between O blood type and pancreatic manifestation of disease in patients with VHL syndrome, especially for PNETs. Screening and surveillance approaches for pancreatic lesions in patients with VHL syndrome should also consider patient blood type. The possibility of A, B, H misexpression in PNETs should also be explored to determine whether the serologic association with disease translates into a relationship with tissue pathology.

ABO blood group and breast cancer incidence and survival

ABO blood type has been associated with risk and survival for several malignancies; however, data for an association with breast cancer are inconsistent. Our study population consisted of Nurses' Health Study participants with self-reported serologic blood type and/or ABO genotype. Using Cox proportional hazards regression, we examined the association between serologic blood type and incident breast cancer among 67,697 women, including 3,107 cases. In addition, we examined the association with ABO genotype in a nested case-control study of 1,138 invasive breast cancer cases and 1,090 matched controls. Finally, we evaluated the association between serologic blood type and survival among 2,036 participants with breast cancer. No clear association was seen between serologic blood type or ABO genotype and risk of total breast cancer, invasive breast cancer or breast cancer subtypes. Compared to women with blood type O, the age-adjusted incidence rate ratios for serologic blood type and total breast cancer were 1.06 (95% CI, 0.98-1.15) for type A, 1.06 (95% CI, 0.93-1.22) for AB and 1.08 (95% CI, 0.96-1.20) for B. In genetic analyses, odds ratios for invasive breast cancer were 1.05 (95% CI, 0.87-1.27) for A/O, 1.21 (95% CI, 0.86-1.69) for A/A, 0.84 (95% CI, 0.56-1.26) for A/B, 0.84 (95% CI, 0.63-1.13) for B/O and 1.17 (95% CI, 0.35-3.86) for B/B, compared to O/O. No significant association was noted between blood type and overall or breast cancer-specific mortality. Our results suggest no association between ABO blood group and breast cancer risk or survival.

Specificity of serum anti-A(di) IgG antibodies from patients with gastrointestinal cancer

Changes in the glycosylation in cancer may lead to an aberrant expression of A, B incompatible or xenogeneic blood group related antigens. To characterize the specificity of IgG antibodies to A, B, and related glycans in sera of gastrointestinal cancer patients, serum probes and affinity-isolated antibodies were analyzed in the indirect and competitive ELISA using a set of homogenous polyacrylamide (PAA) glycoconjugates. Monoreactive antibodies recognizing A(di) (I) and cross-reactive antibodies to A(di)/B(di)/B(tri) (II) or A(di)/A(tri)/Fs(di)/Core5 (III) were affinity-isolated on A(di)-PAA-Sepharose. The population I showed a higher affinity to A(di)-PAA than cross-reactive antibodies. The antibodies II were more specific to B(di) and may belong to the core alpha-Gal reactive antibodies but are also capable of recognizing A(di). The antibodies III were more specific to A(tri); they agglutinated A-erythrocytes and belong to anti-A isoantibodies reactive to xenogeneic oligosaccharides. The purified antibody samples were non- or faintly reactive to Tn. The IC(50) values of PAA glycoconjugates ranged from 6 × 10(-8) to 7 × 10(-6) M. No or weak binding of antibodies to the unrelated antigens used in the detection of polyreactivity (ferritin, casein, and DNA) was observed.

The prognostic and predictive value of serum CA19.9 in pancreatic cancer

Background

Current staging methods for pancreatic cancer (PC) are inadequate, and biomarkers to aid clinical decision making are lacking. Despite the availability of the serum marker carbohydrate antigen 19.9 (CA19.9) for over two decades, its precise role in the management of PC is yet to be defined, and as a consequence, it is not widely used.

Methods

We assessed the relationship between perioperative serum CA19.9 levels, survival and adjuvant chemotherapeutic responsiveness in a cohort of 260 patients who underwent operative resection for PC.

Results

By specifically assessing the subgroup of patients with detectable CA19.9, we identified potential utility at key clinical decision points. Low postoperative CA19.9 at 3 months (median survival 25.6 vs 14.8 months, P = 0.0052) and before adjuvant chemotherapy were independent prognostic factors. Patients with postoperative CA 19.9 levels >90 U/ml did not benefit from adjuvant chemotherapy (P = 0.7194) compared with those with a CA19.9 of ≤90 U/ml (median 26.0 vs 16.7 months, P = 0.0108). Normalization of CA19.9 within 6 months of resection was also an independent favorable prognostic factor (median 29.9 vs 14.8 months, P = 0.0004) and normal perioperative CA19.9 levels identified a good prognostic group, which was associated with a 5-year survival of 42%.

Conclusions

Perioperative serum CA19.9 measurements are informative in patients with detectable CA19.9 (defined by serum levels of >5 U/ml) and have potential clinical utility in predicting outcome and response to adjuvant chemotherapy. Future clinical trials should prioritize incorporation of CA19.9 measurement at key decision points to prospectively validate these findings and facilitate implementation.

Expression of the gene encoding secretor type galactoside 2 α fucosyltransferase (FUT2) and ABH antigens in patients with oral lesions

OBJECTIVE

The aim of this work was to evaluate the expression of FUT2 gene in saliva and histo ABH antigens of patients with oral lesions.

STUDY DESIGN

In total 178 subjects were examined, half of whom suffered from oral pre-cancerous and cancerous lesions, while the other half were the healthy control group We analyzed the FUT 2 polymorphism by ASO-PCR (allele specific oligonucleotid - polymerase chain reaction) with specific primers for G428 allele and the wild type allele of FUT2 gene. To reveal A, B and H antigens in tissue sections of the patients (n= 89) we used a modified specific red cell adherence technique.

RESULTS

We found a high intensity of oral disease in the non-secretor group (OR = 2.43). A total of 58% of the patients with oral pre-cancerous and cancerous lesions was non secretors (se_/_), in contrast with the healthy population (21.5%). A strongly positive reaction was defined as a sheet of indicator erythrocytes adhered to the epithelial cells. In 31 of the 54 samples analyzed the test showed slightly positive results on atypical areas, and there was a complete antigen deletion in areas affected by neoplasia. Nineteen samples showed a total absence of ABH antigens in both histologically normal and pathological areas. Blood group antigens were expressed at a high level in benign and highly differentiated malignant tumors. In poorly differentiated malignant tumors, they were mostly absent.

CONCLUSION

Considering these results we suggest the use of this method to monitor probable preneoplastic lesions in risk population, especially in those with no secretor status (absence of FUT2 gene).

Prognostic influence of loss of blood group A antigen expression in pathologic stage I non-small-cell lung cancer

INTRODUCTION

In the scientific literature, contradictory results has been published on the prognostic value of the loss of expression of blood group antigen A (BAA) in lung cancer. The objective of our study was to analyze this fact in our surgical series.

PATIENTS AND METHODS

In a multicenter study, 402 non-small-cell lung cancer (NSCLC) patients were included. All were classified as stage-I according to the last 2009-TNM classification. We analyzed the prognostic influence of the loss of expression of BAA in the 209 patients expressing blood group A or AB.

RESULTS

The 5-year cumulative survival was 73% for patients expressing BAA vs 53% for patients with loss of expression (P=.03). When patients were grouped into stages IA and IB, statistical significance was only observed in stage I-A (P=.038). When we analyzed the survival according to histologic type, those patients with adenocarcinoma and loss of expression of BAA had a lower survival rate that was statistically very significant (P=.003). The multivariate analysis showed that age, gender and expression of BAA were independent prognostic factors.

CONCLUSIONS

The loss of expression of blood group antigen A has a negative prognostic impact in stage I NSCLC, especially in patients with adenocarcinoma.

The recombinant lectin-like domain of thrombomodulin inhibits angiogenesis through interaction with Lewis Y antigen

Lewis Y Ag (LeY) is a cell-surface tetrasaccharide that participates in angiogenesis. Recently, we demonstrated that LeY is a specific ligand of the recombinant lectin-like domain of thrombomodulin (TM). However, the biologic function of interaction between LeY and TM in endothelial cells has never been investigated. Therefore, the role of LeY in tube formation and the role of the recombinant lectin-like domain of TM-TM domain 1 (rTMD1)-in antiangiogenesis were investigated. The recombinant TM ectodomain exhibited lower angiogenic activity than did the recombinant TM domains 2 and 3. rTMD1 interacted with soluble LeY and membrane-bound LeY and inhibited soluble LeY-mediated chemotaxis of endothelial cells. LeY was highly expressed on membrane ruffles and protrusions during tube formation on Matrigel. Blockade of LeY with rTMD1 or Ab against LeY inhibited endothelial tube formation in vitro. Epidermal growth factor (EGF) receptor in HUVECs was LeY modified. rTMD1 inhibited EGF receptor signaling, chemotaxis, and tube formation in vitro, and EGF-mediated angiogenesis and tumor angiogenesis in vivo. We concluded that LeY is involved in vascular endothelial tube formation and rTMD1 inhibits angiogenesis via interaction with LeY. Administration of rTMD1 or recombinant adeno-associated virus vector carrying TMD1 could be a promising antiangiogenesis strategy.

Studies on the synthesis of Lewis-y oligosaccharides

Lewis-y histo-blood group oligosaccharides are tumour-associated antigens prevalent in several different types of cancer, and they may also be secondary ligands for bacterial toxins from Escherichia coli and Vibrio cholerae. The key step in the synthesis of these sterically congested oligosaccharides involves difucosylation of partially protected lactosamine derivatives. Existing methods require either prolonged reaction times or elaborate glycosyl donors to ensure high stereoselectivity. Herein we report an optimised procedure for using a simple thioglycoside donor that leads to the desired products in high yield and excellent stereoselectivity. It is found that initial glycosylation of the 3'-hydroxy group of lactosamine derivatives in dichloromethane solution can inhibit subsequent glycosylation at the 2-position; however, reaction in toluene solution leads to Lewis-y oligosaccharides in high yield.

Regulation of glycosyltransferases and Lewis antigens expression by IL-1β and IL-6 in human gastric cancer cells

Inflammation of stomach mucosa has been postulated as initiator of gastric carcinogenesis and the presence of pro-inflammatory cytokines can regulate specific genes involved in this process. The cellular expression pattern of glycosyltransferases and Lewis antigens detected in the normal mucosa changed during the neoplassic transformation. The aim of this work was to determine the regulation of specific fucosyltransferases and sialyltransferases by IL-1β and IL-6 pro-inflammatory cytokines in MKN45 gastric cancer cells. IL-1β induced significant increases in the mRNA levels of FUT1, FUT2 and FUT4, and decreases of FUT3 and FUT5. In IL-6 treatments, enhanced FUT1 and lower FUT3 and FUT5 mRNA expression were detected. No substantial changes were observed in the levels of ST3GalIII and ST3GalIV. The activation of FUT1, FUT2 and FUT4 by IL-1β is through the NF-κB pathway and the down-regulation of FUT3 and FUT5 by IL-6 is through the gp130/STAT-3 pathway, since they are inhibited specifically by panepoxydone and AG490, respectively. The levels of Lewis antigens after IL-1β or IL-6 stimulation decreased for sialyl-Lewis x, and no significant differences were found in the rest of the Lewis antigens analyzed, as it was also observed in subcutaneous mice tumors from MKN45 cells treated with IL-1β or IL-6. In addition, in 61 human intestinal-type gastric tumors, sialyl-Lewis x was highly detected in samples from patients that developed metastasis. These results indicate that the expression of the fucosyltransferases involved in the synthesis of Lewis antigens in gastric cancer cells can be specifically modulated by IL-1β and IL-6 inflammatory cytokines.

Multidimensional glycan arrays for enhanced antibody profiling

Carbohydrate-binding antibodies play a critical role in basic and clinical research. Monoclonal antibodies that bind glycans are used to measure carbohydrate expression, and serum antibodies to glycans can be important elements of the immune response to pathogens and vaccines. Carbohydrate antigen arrays, or glycan arrays, have emerged as powerful tools for the high-throughput analysis of carbohydrate-protein interactions. Our group has focused on the development and application of neoglycoprotein arrays, a unique array format wherein carbohydrates are covalently attached to a carrier protein prior to immobilization on the surface. The neoglycoprotein format permits variations of glycan structure, glycan density, and neoglycoprotein density on a single array. The focus of this study was on the effects of neoglycoprotein density on antibody binding. First, we evaluated binding of five monoclonal antibodies (81FR2.2, HE-195, HE-193, B480, and Z2A) to the blood group A antigen and found that neoglycoprotein density had a substantial effect on recognition. Next, we profiled serum antibodies in 15 healthy individuals and showed that inclusion of multiple neoglycoprotein densities helps distinguish different subpopulations of antibodies. Finally, we evaluated immune responses induced by a prostate cancer vaccine and showed that variations in neoglycoprotein density enable one to detect antibody responses that could not be detected otherwise. Neoglycoprotein density is a useful element of diversity for evaluating antibody recognition and, when combined with variations in glycan structure and glycan density, provides multidimensional glycan arrays with enhanced performance for monoclonal antibody development, biomarker discovery, and vaccine optimization.

ABO blood group and incidence of skin cancer

Background

Previous studies have examined the association between ABO blood group and the risk of some malignancies. However, no prospective cohort study to date has examined the association between ABO blood group and the risk of skin cancer.

Methodology/Principal Findings

Using two large cohorts in the US, we examined ABO blood type and incidence of skin cancer, including melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC). We followed up study participants (70,650 female nurses and 24,820 male health professionals) on their diagnosis of incident skin cancer from cohort baseline (1976 in women and 1986 in men) until 2006. Study participants reported their blood type in 1996 in both cohorts. During the follow-up, 685 participants developed melanoma, 1,533 developed SCC and 19,860 developed BCC. We used Cox proportional hazards models to calculate the hazard ratios (HR) and 95% confidence intervals (CI) of each type of skin cancer. We observed that non-O blood group (A, AB, and B combined) was significantly associated with a decreased risk of non-melanoma skin cancer overall. Compared to participants with blood group O, participants with non-O blood group had a 14% decreased risk of developing SCC (multivariable HR: 0.86; 95% CI: 0.78, 0.95) and a 4% decreased risk of developing BCC (multivariable HR: 0.96; 95% CI: 0.93, 0.99). The decreased risk of melanoma for non-O blood group was not statistically significant (multivariable HR: 0.91; 95% CI: 0.78, 1.05).

Conclusion/Significance

In two large independent populations, non-O blood group was associated with a decreased risk of skin cancer. The association was statistically significant for non-melanoma skin cancer. Additional studies are needed to confirm these associations and to define the mechanisms by which ABO blood type or closely linked genetic variants may influence skin cancer risk.

ABH blood group antigens in N-glycan of human glycophorin A

We previously showed that a small proportion of the O-linked oligosaccharide chains of human glycophorin A (GPA) contains blood group A, B or H antigens, relevant to the ABO phenotype of the donor. The structures of these minor O-glycans have been established (Podbielska et al. (2004) [20]). By the use of immunochemical methods we obtained results indicating that ABH blood group epitopes are also present in N-glycan of human GPA (Podbielska and Krotkiewski (2000) [22]). In the present paper we report a detailed analysis of GPA N-glycans using nanoflow electrospray ionization tandem mass spectrometry. N-glycans containing A-, B- and H-related sequences were identified in GPA preparations obtained from erythrocytes of blood group A, B and O donors, respectively. The ABH blood group epitopes are present on one antenna of the N-glycan, whereas a known sialylated sequence NeuAcalpha2-6Galbeta1-4GlcNAc- occurs on the other antenna and other details are in agreement with the known major structure of the GPA N-glycan. In the bulk of the biantennary sialylated N-glycans released from GPA preparations, the blood group ABH epitopes-containing N-glycans, similarly O-glycans, constituted only a minor part. The amount relative to other N-glycans was estimated to 2-6% of blood group H epitope-containing glycans released from GPA-O preparations and 1-2% of blood group A and B epitope-containing glycans, released from GPA-A and GPA-B, respectively.

ABO blood group and incidence of epithelial ovarian cancer

Previous studies have observed an association between ABO blood group and risk of certain malignancies, including ovarian cancer; however, no prospective studies of the association with ovarian cancer risk are available. Using data from 49,153 women in the Nurses' Health Study, we examined the association between ABO blood group and incidence of epithelial ovarian cancer. Study participants reported their blood type and Rh factor in 1996, and 234 women were diagnosed with incident ovarian cancer during 10 years of follow-up. We used Cox proportional hazards regression to model the incidence rate ratios (RR) and 95% confidence intervals (CI) of ovarian cancer for each blood group category. Compared to women with blood group O, women with blood group AB or B had a nonsignificant 38% increase in ovarian cancer incidence (95% CI = 0.88-2.16 for blood group AB and 0.96-1.99 for blood group B), whereas blood group A was not associated with risk (RR = 0.95, 95% CI = 0.70-1.30). Combining blood groups AB and B, we observed a statistically significant positive association with presence versus absence of the B antigen overall (RR = 1.41, 95% CI = 1.06-1.88) and for the serous invasive subtype (RR = 1.53, 95% CI = 1.08-2.17). In this large, prospective cohort of women, presence of the B antigen was positively associated with ovarian cancer incidence, whereas blood group A was not associated with risk. Additional studies are needed to confirm this association and to explore the mechanisms through which blood group may influence ovarian cancer risk.

α(1,2)fucosylation in human colorectal carcinoma

Lewis(b) and Lewis(y) (Le) antigens are known to be elevated in colorectal tumours. Alterations in the catalytic behaviour of GDP-L-fucose:β-D-galactoside α(1,2)fucosyltransferase [α(1,2)FT, EC: 2.4.1.69], the key enzyme in their synthesis, have been suggested as being responsible for these changes. In particular, an aberrant tumour-specific α(1,2)FT activity that converts Le(a) and Le(x) to Le(b) and Le(y) determinants, respectively, has been reported in colorectal cancer tissues. To clarify the catalytic function of this enzyme during colorectal tumorigenesis, we analyzed α(1,2)FT activity levels in healthy and tumour colon specimens using different acceptor substrates and determined the kinetic properties of the enzyme. To complete the study, the aberrant Le(a)/Le(x) α(1,2)fucosylation was determined in healthy and tumour colorectal tissues. A correlation analysis between the activity levels and various standard clinicopathological features, such as tumour stage, was also carried out to elucidate the role of these activities in tumour progression. The results obtained confirm the enhanced α(1,2)fucosylation in colorectal neoplastic tissues and the importance of the aberrant Le(a)/Le(x) α(1,2)FT activity in this increase. However, taking into account the high levels of Le(a)/Le(x) fucosylation observed in healthy control tissues, we must rule out the idea of a colorectal tumour-specific α(1,2)FT. On the other hand, no significant association was observed between α(1,2)FT activity levels and the clinicopathological characteristics. Overall, our results suggest that α(1,2)FT activity plays a critical role in the accumulation of Le(b) and Le(y) antigens in human colorectal carcinoma.

Differentiation of isomeric Lewis blood groups by positive ion electrospray tandem mass spectrometry

Lewis histo-blood group antigens are one of the major classes of biologically active oligosaccharides. In this work, underivatized Lewis blood groups were studied by electrospray tandem mass spectrometry (ESI-MS(n)) in the positive mode with three different mass analyzers: Q-TOF (quadrupole time-of-flight), QqQ (triple quadrupole), and LIT (linear ion trap). It was observed that, under collision-induced fragmentations, type 1 Lewis antigens (Le(a) and Le(b)) could be distinguished from type 2 (Le(x) and Le(y)) on the basis of specific fragmentations of the GlcNAc unit. Whereas O-4-linked sugars of the GlcNAc are lost as residues, the O-3-linked sugars undergo fragmentation both as sugar units and as sugar residues (unit -18Da). Type 2 Lewis antigens also showed a characteristic cross-ring cleavage (0,2)A(2) of the GlcNAc. As a result, the product ions at m/z 388 and 305, characteristic of Le(x), and m/z 372, characteristic of Le(a), are proposed to distinguish the trisaccharide isomers Le(x)/Le(a). Also, the product ions at m/z 534 and 305, characteristic of Le(y), and m/z 372, characteristic of Le(b), are proposed to distinguish the tetrasaccharide isomers Le(b)/Le(y). These diagnostic fragment ions were further applied in the identification of Lewis type 2 antigens (Le(x) and Le(y)) in the lipopolysaccharide of the human gastric pathogen, Helicobacter pylori.

Identification of blood group A/A-Leb/y and B/B-Leb/y active glycotopes co-expressed on the O-glycans isolated from two distinct human ovarian cyst fluids

Although the individual human blood group A and B determinants are well defined, their co-expression pattern on a particular glycan carrier in individuals of blood group AB status has not been delineated. To address this issue, complex O-glycans were isolated from two distinct sources of human ovarian cyst glycoproteins (HOC 89 and Cyst 19) and profiled by advanced MS analyses, in conjunction with defining their binding characteristics against a panel of lectins and monoclonal antibodies. The major O-glycans of HOC 89 were found to correspond to sialyl Tn, mono- and di-sialyl T structures, whereas those of Cyst 19 were apparently more heterogeneous and extended to larger sizes. A minimal structure that carries both A and B determinants on the same molecule was identified, in which the A epitope is attached directly to the core GalNAc, whereas the B epitope is preferentially located on the six arms of a core 2 structure. Both arms can be further extended with internal fucosylation that appears to be restricted to those non-sialylated chains already carrying the terminal ABH determinants, thus giving rise to rather prominent A/B-Le(b/y) glycotopes on larger O-glycans.

Induction of sialyl-Lex expression by herpes simplex virus type 1 is dependent on viral immediate early RNA-activated transcription of host fucosyltransferase genes

We have previously shown that varicella-zoster virus (VZV) and cytomegalovirus (CMV) infection of diploid human fibroblasts (HEL) results in neo-expression of Lewis antigens sialyl Lewis x (sLe(x)) and Lewis y (Le(y)), respectively, after transcriptional activation of different combinations of dormant human fucosyltransferase genes (FUT1, FUT3, FUT5, and FUT6), whose gene products are responsible for the synthesis of Le antigens. Here, we show that herpes simplex virus type 1 (HSV-1) also induces sLe(x) expression dependent on induction of FUT3, FUT5, and FUT6 transcription in infected cells. HSV-1 induction of FUT5 was subsequently used as a model system for analyzing the mechanism of viral activation of dormant fucosyltransferase genes. We show that this is a rapid process, which gives rise to elevated FUT5 RNA levels already at 90 min postinfection. Augmented FUT5 transcription was found to be dependent on transcription of viral genes, but not dependent on the immediate early proteins ICP0 and ICP4, as demonstrated by experiments with HSV-1 mutants defective in expression of these genes. Augmented FUT5 transcription takes place in cycloheximide-treated HSV-1-infected cells, suggesting a more direct role for IE viral RNA during activation of cellular FUT5.

Functionally fused antibodies--a novel adjuvant fusion system

Antibodies capable of recognizing key molecular targets isolated e.g. by phage display technology have been used in the pursuit of new and improved therapies for prevalent human diseases. These approaches often take advantage of non-immunogenic antibody fragments to achieve specific toxin-, radioactivity- or effector-domain delivery. There is now a growing interest in using anti-idiotypic antibodies or other antigen mimics to induce potent immune responses against antigen structures in question. We have earlier reported on the functional rescue of antibodies that are active when fused to the phage, but inactive as soluble protein [Jensen, K.B., Larsen, M., Pedersen, J.S., Christensen, P.A., Alvarez-Vallina, L., Goletz, S., Clark, B.F. and Kristensen, P. (2002) Functional improvement of antibody fragments using a novel phage coat protein III fusion system. Biochem. Biophys. Res. Commun. 298, 566-73.]. The rescue was accomplished by maintaining the fusion between the antibody fragment and portions of the filamentous bacteriophage coat protein 3, as present in the original antibody-displaying phage. In the present study, we have applied this system in an attempt to improve immunogenicity of anti-idiotypic antibodies isolated by phage display. Here we demonstrate that by preserving linkage between phage antibody and the N-terminal domain of phage coat protein 3, we induce multimerization of the antibody fragments, and improve their immunogenicity. This immunization approach allows induction of anti-idiotypic antibodies in mice, and facilitates the use of antibodies that are non-functional as non-fused soluble protein.

Expression of histo-blood group A type 1, 2 and 3 antigens in normal skin and extramammary Paget's disease

The distribution of histo-blood group A type 1, 2 and 3 antigens was investigated using immunohistochemistry in normal human skin and extramammary Paget’s disease (EMPD). We used monoclonal antibodies (mAbs) Bioclone-A (BA) and AR-1, which react with histo-blood group A type 1/2, and type 3 antigens, respectively. We found that A type 1, 2 and 3 antigens were expressed in the upper layer of the epidermis. We also found that the duct cells of the eccrine glands expressed A type 1/2 antigens and A type 3 antigens regardless of secretor status. The dark cells of the eccrine glands expressed A type 1, 2 and 3 antigens from A blood group secretors, but not from non-secretors. Apocrine glands, hair follicles and sebaceous glands did not express these antigens. Since these antigens were localized in the eccrine glands, we examined the possibility of a skin tumor marker. Interestingly, 7 out of 16 extramammary Paget’s disease cases were immunopositive for these antigens. Six cases were accompanied by dermal invasion. Five cases without dermal invasion were immunonegative against these antigens. These results suggest that the expression of histo-blood group A antigens in EMPD are associated with a poor histopathological prognosis.

Novel sugar-cholestanols as anticancer agents against peritoneal dissemination of tumor cells

Chemically synthesized sugar-cholestanols with mono-, di-, and tri-saccharides attached to cholestanol showed strong inhibiting activity against the proliferation of colorectal and gastric cancer cells. In contrast, cholestanol without sugar moieties was totally ineffective. Furthermore, when cancer cells were exposed to GlcNAcRbetacholestanol (R=(-) or beta1-3Gal), the compound was rapidly taken up via the lipid rafts/microdomains on the cell surface. The uptake of sugar-cholestanol in mitochondria increased gradually and was followed by the release of cytochrome c from mitochondria and the activation of apoptotic signals through the mitochondrial pathway and the caspase cascade, leading to apoptotic cell death, characterized by DNA ladder formation and nuclear fragmentation. Additionally, the examination of GlcNAcRbetacholestanol in a mouse model of peritoneal dissemination showed a dramatic reduction of tumor growth (P < 0.003) and prolonged mouse survival time (P<0.0001). Based on these observations, we believe that the sugar-cholestanols described here have clinical potential as novel anticancer agents.

ABO histo-blood groups and Rh systems in relation to malignant tumors of the digestive tract in Bosnia and Herzegovina

The distribution of ABO blood groups and the Rhesus factor was analyzed in 279 patients who suffered from malignant tumors of the digestive system. Patients were registered retrospectively in the Gastroenterohepatology Clinic, Clinical Center, University of Sarajevo over a discontinuous period of 88 months. From the results obtained, it was concluded that: (a) men became ill from gastric cancer significantly more frequently than women; (b) the frequency of liver carcinoma was three times higher than the global frequency and the frequency neighboring ethnic groups; and (c) patients with blood group B and patients with RhD(-) exhibited a significantly higher proportion of disease.

Tumors: too sweet to remember?

Immunity, based on a natural and an educated system, is responsible for recognition and elimination of infectious particles, cellular waste, modified self and transformed cells. This dual system guarantees that dangerous particles are removed immediately after appearance and that a memory with maturated weapons exists, if the organism is re-infected by the same particle. For malignant cells, however, the immune response seems to be restricted to innate immunity, because at least for the humoral response, all so far detected tumor-specific antibodies belong to the natural immunity. In this review we try to explain why malignant cells might be "too sweet" to induce a memory.

Glycosylation of the two O-glycosylated domains of human MUC2 mucin in patients transposed with artificial urinary bladders constructed from proximal colonic tissue

Transposition of intestinal segments is frequently used for bladder reconstruction. Following transposition, bowel segments continue to produce mucus and a correlation between excessive mucus production and complications such as urinary tract infection or catheter blockage has been observed for a long time. However, no information is currently available on the change of mucin expression and glycosylation under these abnormal conditions. In this study, the variable number tandem repeat region and the irregular repeat domain of human MUC2 were isolated as two glycopeptide populations after reduction and trypsin digestion followed by gel chromatography from urine of patients transposed with urinary bladders. After alkaline borohydride treatment, the oligosaccharides released from the whole MUC2 mucin and the two glycosylated domains were investigated by nanoESI Q-TOF MS/MS (electrospray ionization quadrupole time-of-flight tandem mass spectrometry). More than 60 different glycans were identified, mainly based on sialylated core 3 structures. Some core 1, 2 and 4 oligosaccharides were also found. Most of the structures were acidic with NeuAc residues mainly alpha2-6 linked to the N-acetylgalactosaminitol and sulphate residues exclusively 3-linked to galactose. No expression of blood group A and B or Sda/Cad determinants was observed. Similar patterns of glycosylation were found in the tandem repeat region and the irregular repeat domain and the level of expression of the major oligosaccharides were in the same order of magnitude. The most interesting feature of this study was that sialyl-Tn antigen, which is considered as a tumour antigen, was the oligosaccharide most highly expressed. This result suggests that mucins from intestinal transposed segments are abnormally glycosylated.

Natural antibodies and cancer

Immunity is not only responsible for recognition and elimination of infectious particles, but also for removal of cellular waste, modified self structures and transformed cells. Innate or natural immunity acts as a first line defense and is also the link to acquired immunity and memory. A striking phenomenon of immunity against malignant cells is that neither in animals nor in humans affinity-maturated tumor-specific IgG antibodies have been detected so far. All tumor-specific isolated antibodies were germ-line coded natural IgM antibodies. It's also a fact that these IgM's preferentially bind to carbohydrate epitopes on post-transcriptionally modified surface receptors and that they all induce a cancer-specific apoptosis, by triggering the intrinsic apoptotic pathway. From an evolutionary point of view, this makes sense because cancer cells are not infectious, so there is no need for memory. Natural IgMs bind to conservative structures because they are coded by a limited set of genes and they use apoptosis, the "clean" way of killing, to avoid inflammatory processes.

Chemically synthesized sugar-cholestanols possess a preferential anticancer activity involving promising therapeutic potential against human esophageal cancer

The understanding of the cell signaling pathways and the molecular events leading to cell death of cancer cells will provide in-depth perspective into the identification and development of potent anticancer agents. A balance between cell proliferation and cell death has been raised as a rational target for the management of malignant tumors. In the present study, the authors demonstrated that chemically synthesized sugar-cholestanols consisting of GlcNAcbeta-, Galbeta- and GlcNAcbeta1,3Galbeta-cholestanols exerted a strong inhibiting activity against cell proliferation of esophageal cancer cells, but cholestanol itself did not show such an activity against the same cancer cells at all. In addition to their predominant role as an antiproliferation agent, evidence based on the molecular analyses suggested that sugar-cholestanols played a regulatory role in multiple signal transduction pathways inducing apoptosis through both the death signal-extrinsic and the mitochondria-intrinsic pathways. Sugar-cholestanols seemed to be more susceptible to esophageal cancer cells than to non-cancerous esophageal cells at the very early event of their exposure and, further, to suppress specifically the expression of vascular endothelial growth factor. Taken together, these novel functions of sugar-cholestanols indicate that they could have promising therapeutic potential against human esophageal cancer.

Ultrastructural localization of glycodelin oligosaccharides Le-x and Le-y in human seminal vesicles by immunogold staining

Histo-blood group antigens Le-x and Le-y are oligosaccharidic terminals that characterize many glycoproteins in the human tissues. In seminal plasma, they are expressed as part of the so-called glycodelin S, which is suggested to regulate sperm capacitation/decapacitation. It has recently been demonstrated that the core protein of glycodelin S is secreted by seminal vesicles. Here we show that epithelial cells of human seminal vesicles also release the Le-x and Le-y antigens. The presence of these substances in secretory material was revealed by means of an immunogold staining method in normal surgical samples. The results suggest that glycodelin S is secreted by seminal vesicles in its finished glycosylated form. Moreover, antigen reactivity was also revealed associated with plasma membranes.

Changes in the invasive and metastatic capacities of HT-29/M3 cells induced by the expression of fucosyltransferase 1

Lewis antigens are terminal fucosylated oligosaccharides synthesized by the sequential action of several glycosyltransferases. The fucosyltransferases are the enzymes responsible for the addition of terminal fucose to precursor oligosaccharides attached to proteins or lipids. These oligosaccharides, defined as cell surface markers, have been implicated in different types of intercellular interactions and in adhesion and invasion processes. Transfection of HT-29/M3 colon cancer cells with the full length of human fucosyltransferase (FUT1), induces the synthesis of H type 2 and Lewis y antigens, associated with a decrease of sialyl-Lewis x. The capacity to develop primary tumors when cells were injected intrasplenically was similar in parental and FUT1-transfected cells, but the capacity to colonize the liver after spleen removal was significantly reduced in M3/FUT1 transfected cells. These results indicate that the expression of FUT1 induces changes in the metastatic capacity of HT-29/M3 colon cancer cells, as a consequence of the altered expression pattern of type 2 Lewis antigens. Also, an association between MUC5AC expression and the degree of gland differentiation in both primary splenic tumors and hepatic metastases was detected.

A Monoclonal Antibody to Lewis Y/Lewis b Revealing Mimicry of the Histone H1 to Carbohydrate Structures

Antibodies to either peptide or carbohydrate tumour antigens are established tools for diagnostics and therapy. We here describe an antibody (A70-A/A9) recognizing a carbohydrate epitope common to the tumour-associated Lewis Y and Lewis b antigens (Fucalpha1-2Galbeta1-4/3[Fucalpha1-3/4]GlcNAcbeta-). Its specificity was established without doubt with a panel of 86 synthetic mono- and oligosaccharidic structures. This antibody was found to cross-react with the nuclear protein histone H1. Binding to H1 was specific, periodate-insensitive (non-carbohydrate) and saturable. Histone H1 was able to inhibit Lewis Y binding very effectively in a concentration-dependent manner. We conclude that it represents an example of natural peptide mimicry of a carbohydrate epitope. It may explain the observed occurrence of 'anti-histone autoantibodies' in cancer patients.

Alpha1,2fucosylation is a superior predictor of postoperative prognosis for colorectal cancer compared with blood group A, B, or sialyl Lewis X antigen generated within colorectal tumor tissues

BACKGROUND

We have previously demonstrated tumor-specific alpha1,2fucosylation, which is associated with resistance of tumor cells to anticancer treatment in human colorectal tumor tissues. By using the YB-2 monoclonal antibody, the resulting products have been identified as Y, Le(b), and H type 2 antigens in colorectal tumor tissues.

METHODS

Immunohistochemical analyses of colorectal cancer tissues (74 specimens) were performed with a newly established mouse monoclonal antibody, YB-3 specifically recognizing H disaccharide (Fucalpha1,2Galbeta) structures, and anti-A, anti-B, YB-2, and anti-sialyl Lewis X (SLX) antibodies, together with the analyses of glycosyltransferases involved in the synthesis of ABH antigens in the same tissues.

RESULTS

The YB-3 antibody enabled us to detect colorectal tumors, particularly tumors in the distal large intestine and the rectum, with high sensitivity (74.3%) and specificity (100%). From immunohistochemical and enzymatic analyses of colorectal tissues, we found that once alpha1,2fucosylation had proceeded in tumor tissues, blood group A or B antigen was also synthesized in approximately half of the tissues of A or B blood type, but not in their normal tissues. A correlation of survival rate with immunostaining of tissues was found only by YB-3 antibody and not by anti-A, anti-B, or anti-SLX antibody.

CONCLUSIONS

As a predictor of postoperative prognosis of patients with colorectal cancer, immunodetection of alpha1,2fucosylated antigens with the YB-3 antibody seemed to be superior to blood groups A, B, or SLX antigen in colorectal tumor tissues.

Cell surface fucosylation does not affect development of colon tumors in mice with germline Smad3 mutation

BACKGROUND/AIMS

Neoplasia-related alterations in cell surface alpha(1,2)fucosylated glycans have been reported in multiple tumors including colon, pancreas, endometrium, cervix, bladder, lung and choriocarcinoma. Spontaneous colorectal tumors from mice with a germline null mutation of transforming growth factor-beta signaling gene Smad3 (Madh3) were tested for alpha(1,2)fucosylated glycan expression.

METHODS

Ulex europaeus agglutinin-I (UEA-I) lectin staining, fucosyltransferase gene Northern blot analysis, and a cross of mutant mice with Fut2 and Smad3 germline mutations were performed.

RESULTS

Spontaneous colorectal tumors from Smad3 (-/-) homozygous null mice were found to express alpha(1,2)fucosylated glycans in an abnormal pattern compared to adjacent nonneoplastic colon. Northern blot analysis of alpha(1,2)fucosyltransferase genes Fut1 and Fut2 revealed that Fut2, but not Fut1, steady-state mRNA levels were significantly increased in tumors relative to adjacent normal colonic mucosa. Mutant mice with a Fut2-inactivating germline mutation were crossed with Smad3-targeted mice. In Smad3 (-/-)/Fut2 (-/-) double knockout mice, UEA-I lectin staining was eliminated from colon and colon tumors; however, the number and size of tumors present by 24 weeks of age did not vary regardless of the Fut2 genotype.

CONCLUSIONS

In this model of colorectal cancer, cell surface alpha(1,2)fucosylation does not affect development of colon tumors.

Expression of carbohydrate antigens in human esophageal squamous cell carcinoma: prognostic application and its diagnostic implications

BACKGROUND

Tumor markers whose antigenic determinants have been demonstrated to consist of carbohydrates are probably one of the most extensive tools that have been used in routine cancer diagnosis. In this study, the relevance of carbohydrate antigen expression profile was examined in esophageal squamous cell carcinoma together with prognosis in 130 patients.

METHODS

The expression of carbohydrate antigens was estimated immunohistochemically by anti-sialyl Lewis a (sialyl Le(a)) and anti-sialyl Lewis x (sialyl Le(x)) monoclonal antibodies, and correlation between their staining and clinicopathological status was examined. In addition, the correlation of both carbohydrate antigens expression was evaluated with microvessel density (MVD).

RESULTS

Expressions of sialyl Lewis antigens and MVD were associated with several clinicopathological features that reflect the tumor aggressiveness in esophageal cancer. The 5-year survival rate of patients was found to be associated with expression of sialyl Le(a) and sialyl Le(x) antigens and with MVD; thus, all of them were revealed to be independent prognostic factors.

CONCLUSIONS

Combination of these factors offered a better prediction of prognosis of esophageal squamous cell carcinoma. Further, carbohydrate antigens represent a promising target for therapeutic approaches against the disease.

Modulation of ABH histo-blood group antigen expression in normal and myasthenic human thymus

The role of ABH histo-blood group antigens (HBGA) in intercellular communication during normal and pathological processes is still uncertain. The present work investigates the expression of ABH HBGA in epithelial cells and lymphocytes in normal thymus, and characterizes the modulation of their immunoreactivity during myasthenic transformation. Immunohistochemistry and immunoelectron microscopy were applied on normal young thymus and on myasthenia gravis-associated thymomas and thymic hyperplasias. The Hassall's corpuscules in the thymus of young individuals were homogeneously stained for HBGA, while in hyperplastic glands only their central part was positive. Stromal epithelial cells permanently expressed HBGA in all tissue samples. In thymomas, mainly the lymphocytes in close proximity to antigen expressing epithelial cells were positive, while in the hyperplastic gland the most intensely stained lymphocytes were those within Hassall's corpuscules. Novel evidence for modulation of ABH antigen reactivity in normal and myasthenic human thymus is presented. It suggests that HBGA might participate in the regulation of the cross-talk in the thymocyte microenvironment throughout the ontogeny, as well as during the myasthenic transformation.

Modulating expression of LAMPs and ABH histo-blood group antigens in normal and neoplastic human skin

Although the precise biological role of lysosomal membrane-associated glycoproteins (LAMPs) and ABH histo-blood group antigens (HBGAs) remains somewhat unclear, they are thought to be related to cell differentiation, cellular adhesion, and tumorigenesis. Here, we present the first comparative immunohistochemical study of both LAMPs and HBGAs in normal and neoplastic skin. Their localization is compared to that of high molecular weight cytokeratin and cytokeratin MNF 116. LAMPs and HBGA were differentially expressed in the normal stratified squamous epithelium, suggesting that they are involved in the initial steps of the differentiation process, whereas HBGAs are characteristic of terminal keratinocyte differentiation. No change in the reactivity for HBGA was detected in the stratified epithelium overlying squamous cell or basal cell carcinomas, whereas a considerable loss of LAMPs was detected. LAMPs were overexpressed in tumor cells, whereas HBGAs were lost in tumor zones of basocellular carcinomas. In spinocellular carcinomas, HBGAs were detected in tumor keratinocytes and in keratin pearls. These results provide new evidence for the differential expression of LAMPs and HBGAs in the normal stratified squamous epithelium, as well as the presence of a modulating reactivity in basocellular and spinocellular carcinomas, suggesting that these glycoproteins are involved in differentiation and tumorigenesis of human skin.

Relationship between ?Gal epitope expression and decrease of tumorigenicity in pancreatic adenocarcinoma model

The alphaGal epitope is a carbohydrate structure, Galalpha1,3Galbeta1,4GlcNAc-R, synthesized on glycoconjugates in many mammals by alpha1,3galactosyltransferase. Humans do not express this epitope and present in serum large amounts of naturally occuring antibodies, which recognize the alphaGal epitopes and participate in the hyperacute rejection of xenograft. Studies indicated that the fundamental mechanism of hyperacute rejection involving the alphaGal epitope expression can be used in cancer therapy. We have previously suggested that the alphaGal epitope expression by human pancreatic tumoral cells could decrease the tumorigenic behavior of these cells. To determine whether the expression of the alphaGal epitope can modify the tumorigenicity of pancreatic cancer cells, we used a Syrian golden hamster pancreatic adenocarcinoma experimental model. The expression of alphaGal epitopes in the Syrian golden hamster pancreatic cancer cell line HaP-T1 was obtained by selecting stable cell clones transfected with murine alpha1,3galactosyltransferase gene. The alphaGal epitope expression resulted in a delay in the tumoral development of HaP-T1 cells in vivo after allograft transplantation of Syrian golden hamsters (2.5-fold, P < 0.05) and of nude mice. This result is associated with an 100% increase in survival time of nude mice bearing tumors expressing the alphaGal epitope. Our results confirm that the cell surface expression of alphaGal epitope decreases the tumorigenic behavior of pancreatic cancer cells. This novel property may be useful for the development of cancer gene immunotherapy strategy.

Expression of sialyl-Tn epitopes on beta1 integrin alters epithelial cell phenotype, proliferation and haptotaxis

Sialyl-Tn (STn) is a tumor-associated carbohydrate antigen overexpressed in various carcinomas. To obtain its expression, murine carcinoma cells were transfected with the cDNA encoding ST6GalNAc I, a glycosyltransferase that acts exclusively on O-glycans. Overexpression of this enzyme led to the expected expression of cell surface STn epitopes. Surprisingly, the transfectants (STn+ cells) presented dramatic morphological changes and altered behavior. These STn+ cells lost the epithelial appearance of parental cells, became larger, more elongated and presented disorganized actin stress fibers. Additionally, their proliferation was impaired and their ability to migrate on fibronectin and hyaluronic acid was severely reduced. By contrast their adhesion on fibronectin remained unchanged. The major glycoprotein carrying the STn epitope was shown to be the integrin beta1 subunit. Anti-STn antibodies could restore migration of STn+ cells on fibronectin. A constitutively active permeant form of RhoA (TAT-RhoA(Val-14)) also restored motility on fibronectin of STn+ cells as well as a parental STn-cellular phenotype. These observations indicate that overexpression of ST6GalNAc I leads to a major change of the O-glycosylation of the integrin beta1 chain which in turn impairs the integrin-mediated signalling and leads to major alterations in morphology and cell behavior.

ABH blood group antigens in O-glycans of human glycophorin A

The major O-linked oligosaccharide structures attached to human glycophorin A (GPA) have been extensively characterized previously. Our own recent findings, obtained by immunochemical methods, suggested the presence of blood group A and B determinants in O-glycans of human glycophorin originating from blood group A or B erythrocytes, respectively. Here, we elucidate the structure of O-glycans, isolated from GPA of blood group A, B, and O individuals by reductive beta-elimination, carrying A, B or H blood group epitopes, respectively. Structural studies based on nanoflow electrospray-ionization tandem mass spectrometry and earlier reported data on the carbohydrate moiety of GPA and ABH antigens allowed us to conclude that these blood group epitopes are elongations of the beta-GlcNAc branch attached to C-6 of the reducing GalNAc. The galactose linked to C-3 of the reducing GalNAc carries NeuAcalpha2-3 linked residue. Identified here O-glycans were found in low amounts, their content estimated at about one percent of all GPA O-glycans. These O-glycans with type-2 core, carrying the blood group A, B or H determinants, have not been identified in GPA so far. Our results demonstrate the efficacy of nanoESI MS/MS in detecting minor oligosaccharide components present in a mixture with much more abundant structures.

Histo-blood group ABO antigen in oral potentially malignant lesions and squamous cell carcinoma--genotypic and phenotypic characterization

Loss of histo-blood group A/B antigens is frequent in oral cancer. It is unclear whether this alteration is due to loss of the chromosomal region encoding the genes. The aim was to investigate genotypic alterations in the ABO locus in oral potentially malignant lesions and carcinomas. Seventy-three cases which expressed A/B antigen in normal epithelium by immunohistochemical (IHC) staining were investigated. Both tumour and normal cells were collected from paraffin-embedded tissue by laser microdissection. DNA was extracted and analysed by PCR coupled with restricted digestion analysis in order to establish the ABO genotype. Total and patchy loss of A/B antigen expression was found in 24/32 carcinomas, 6/7 leukoplakias with severe dysplasia, 12/17 leukoplakias with mild and moderate dysplasia, and 6/17 leukoplakias without dysplasia. Specific A/B allele loss was found in 8/24 cases with carcinoma and 3/24 cases with mild and moderate dysplasia by genotyping analysis. O allele loss was found in 10 cases involving all four groups. In patients with heterozygous genotypes, A/B allelic loss by genotyping analysis was always followed by loss of A/B antigen expression by IHC staining. Loss of A/B antigen expression in tissues which had intact ABO alleles was, however, found and may be explained by other genetic and epigenetic changes.

Genetic and epigenetic alterations of the blood group ABO gene in oral squamous cell carcinoma

Loss of histo-blood group A and B antigen expression is a frequent event in oral carcinomas and is associated with decreased activity of glycosyltransferases encoded by the ABO gene. We examined 30 oral squamous cell carcinomas for expression of A and B antigens and glycosyltransferases. We also examined DNA from these tumors for loss of heterozygosity (LOH) at markers surrounding the ABO locus at chromosome 9q34, for loss of specific ABO alleles, and for hypermethylation of the ABO promoters. Loss of A or B antigen expression was found in 21 of 25 tumors (84%) and was a consistent feature of tumors lacking expression of A/B glycosyltransferases. LOH at 9q34 was found in 7 of 27 cases (26%), and one case showed microsatellite instability. Among 20 AO/BO cases, 3 showed loss of the A/B allele and 3 showed loss of the O allele. Analysis of the proximal ABO promoter by methylation-specific PCR and melting curve analysis showed hypermethylation in 10 of 30 tumors (33.3%), which was associated with loss of A/B antigen expression. ABO promoter hypermethylation was also found in hyperplastic or dysplastic tissues adjacent to the tumors, suggesting that it is an early event in tumorigenesis. Collectively, we have identified molecular events that may account for loss of A/B antigen expression in 67% of oral squamous cell carcinomas.

Decrease of human pancreatic cancer cell tumorigenicity by alpha1,3galactosyltransferase gene transfer

The enzyme alpha1,3galactosyltransferase synthesizes the alphaGal epitope, a carbohydrate structure (Galalpha1,3Galbeta1,4GlcNAc-R), on glycoconjugates in lower mammals. The enzyme is absent in humans but large amounts of natural antibodies that recognize alphaGal epitopes are present in human serum. It is likely that these antibodies contribute to the host defense and participate in the hyperacute rejection of xenograft. Previous studies indicated that the glycosyltransferase gene transfer into tumoral cells can modify the structure of glycoconjugates at the cell surface and, as a consequence, modulates the metastatic and tumorigenic behaviors of these cells. The aim of our study was to determine whether the expression of alphaGal epitope can modify the tumorigenicity of human pancreatic cancer cells. The expression of alphaGal epitopes in the human pancreatic cancer cell lines BxPC-3 and Panc-1 was obtained by selecting stable cell clones transfected with murine alpha1,3galactosyltransferase gene. The expression of the enzyme activity in BxPC-3 and Panc-1 cells resulted in the formation at the cell surface of alphaGal epitopes that are recognized by human anti-alphaGal antibodies. alphaGal epitope expression at the surface of pancreatic cancer cells was associated with the fixation of complement 1q to human anti-alphaGal antibodies. The alphaGal epitope expression also resulted in a delay in the tumoral development of BxPC-3 and Panc-1 cells in vivo after xenograft transplantation of nude mice. In addition to the impairment of the metastatic potential of murine tumor cell lines and the activation of immune response, our study provides evidence that the cell surface expression of alphaGal epitopes also modulates the tumorigenic behavior of human pancreatic cancer cells.

?1-Acid glycoprotein fucosylation as a marker of carcinoma progression and prognosis

BACKGROUND

Serum alpha1-acid glycoprotein (AGP), an acute-phase protein secreted by the liver, carries alpha(1,3)-fucosylated structures on its 5 highly branched, N-linked sugar chains.

METHODS

Serum AGP levels in patients with various types of malignancies (n=214 patients) were measured using an enzyme-linked immunosorbent assay with anti-AGP antibody. To investigate glycoforms that differed in their degree of branching and extent of fucosylation, serum AGP samples were analyzed by crossed affinoimmunoelectrophoresis (CAIE) with concanavalin A, and Aleuria aurantia lectin (AAL), and anti-AGP antibody.

RESULTS

A significant difference (P <0.001) in serum AGP levels was observed in preoperative patients compared with levels in the healthy control group, but the levels in individual patients did not reflect their clinical status. Conversely, it was found not only that the patterns of AGP glycoforms differed widely in the patient group compared with the healthy control group, but they also changed depending on each patient's clinical status. Furthermore, AGP glycoforms seemed to be appropriate markers of disease progression and prognosis according to follow-up studies of 45 patients during prolonged preoperative and postoperative periods.

CONCLUSIONS

Patients with advanced malignancies who had AGP glycoforms that contained highly fucosylated triantennary and tetraantennary sugar chains for long periods after surgery were likely to have a poor prognosis. However, patients who had AGP glycoforms without such changes were expected to have a good prognosis.

Expression of histo-blood group A antigen increases resistance to apoptosis and facilitates escape from immune control of rat colon carcinoma cells

A and B histo-blood group antigens are present on carcinoma cells at the early stages of cancerogenesis and tend to disappear at later stages, but it is not yet clear whether they take part to the process of tumor progression. To gain some insight into this issue, we used a rat colon carcinoma experimental model. To obtain expression of the A antigen, REG cells were cotransfected with the rat A enzyme cDNA and a rat alpha1,2fucosyltransferase cDNA, either FTA or FTB, whereas PRO cells that spontaneously have alpha1,2fucosyltransferase activity were only transfected with the A enzyme cDNA. All A antigen-expressing transfected cells derived from either REG FTA, REG FTB, or PRO parental cells were more resistant to apoptosis induced by either serum deprivation or heat shock than were their respective controls. When injected to syngeneic immunocompetent rats, A enzyme-transfected PRO cells formed tumors that grew faster than those formed by mock-transfected PRO cells. However, in immunodeficient SCID mice, no difference in growth could be observed between the two types of tumors, indicating that the faster tumor growth of the A antigen-positive cells in immunocompetent animals was due to their higher ability to escape immune control and that this was associated with their higher degree of resistance to apoptosis. These results might explain the slightly augmented incidence of carcinomas observed in A and B blood group individuals compared to O individuals.

Tumor-related expression of alpha1,2fucosylated antigens on colorectal carcinoma cells and its suppression by cell-mediated priming using sugar acceptors for alpha1,2fucosyltransferase

The accumulation of alpha1,2fucosylated antigens, such as Y (Fucalpha1,2Galbeta1,4 [Fucalpha1,3]GlcNAcbeta), Le(b) (Fucalpha1,2Galbeta1,3-[Fucalpha1,4]GlcNAcbeta), and H type 2 (Fucalpha1,2 Galbeta1,4GlcNAcbeta) occurs specifically within human colorectal tumor tissues and can be detected by an antifucosylated antigen antibody, such as the YB-2 antibody. In the present investigation, we found that the expression of these antigens bearing an alpha1,2-linked fucose correlated with the resistance of the tumor cells to anticancer treatments. Addition of an exogenous sugar acceptor for alpha1,2fucosyltransferase to the cell medium resulted in suppression of alpha1,2fucosylated antigen expression on the tumor cells and increased susceptibility to anticancer treatment. The increased susceptibility may be attributed to cancer cell-mediated priming by sugar acceptors for alpha1,2fucosyltransferase added to the medium.

ABO blood group antigens in oral mucosa. What is new?

Histo-blood group ABH (O) antigens are major alloantigens in humans. These antigens are widely distributed in human tissues and undergo changes in expression during cellular differentiation and malignant development. The ABH antigens have been characterized as terminal disaccharide determinants which represent secondary gene products. They are synthesized in a stepwise fashion from a precursor by the action of different glycosyltransferases. In non-keratinized oral mucosa, a sequential elongation of the carbohydrates is associated with differentiation of epithelial cells, resulting in expression of precursors on basal cells and A/B antigens on spinous cells. Reduction or complete deletion of A/B antigen expression in oral carcinomas has been reported, a phenotypic change that is correlated with invasive and metastatic potential of the tumours and with the mortality rates of the patients. Disappearance of the antigens is ascribed to the absence of A or B transferase gene expression. Several studies have shown that loss of A and B antigen expression is associated with increased cell motility, invasion in matrigel, and tumourigenecity in syngenic animals. In vivo studies of human oral wound healing show similarly decreased expression of A/B antigens on migrating epithelial cells. Some studies suggest that the relationship between expression of blood group antigens and cell motility can be explained by different degrees of glycosylation of integrins. Changes in ABO expression in tumours have, in some cases, been due to the A/B gene promoter, although little is known about the regulation of A, and B expression, in normal tissue.