| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Regular Articles |
Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut 06520-8059
 |
ABSTRACT |
|---|
 Top ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
|
INTRODUCTION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
-1,6-mannose in the pentasaccharide core of acceptor glycans, forming a ß1,6-branched structure in the production of tri- or tetra-antennary N-glycans (25
, 26)
. ß1,6-GlcNAc-linked, polylactosamine antennae on N-glycans are a normal feature of granulocytes and monocytes and have also been associated with malignant cells (3
, 4
, 15 , 16
, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
. The polylactosamine antennae are carriers of Lewisx and Lewisa antigens, used on N-, and O-glycans by both normal leukocytes and tumor cells in selectin binding during intravasation and systemic migration (10
, 37, 38, 39)
. GNT-V expression results in loss of contact inhibition and decreased substrate adhesion, increased susceptibility to apoptosis, and increased tumorigenicity in nude mice (40
, 41)
. GNT-V-deficient mice show suppressed tumor growth and lowered incidence of metastasis (42)
. Increased ß1,6-branched N-glycans on ß1 integrin reduced 5ß1 integrin clustering and stimulated in vitro migration of human fibrosarcoma cells (43)
. The lectin, LPHA (phaseola vulgaris) shows high-affinity binding to ß1,6-branched N-glycans and can be used in lectin histochemistry to detect these oligosaccharides in formalin-fixed, paraffin-embedded tissues (13 , 44) . However, little has been reported on the histology of LPHA-positive cells in human cancer, and the two existent studies investigated only primary tumors. One study of primary breast and colon carcinomas described LPHA staining of "coarse granules and globules located in the cytoplasm in a supranuclear position" (13) . Another study of primary breast carcinomas described LPHA reactivity as "diffuse cytoplasmic staining, sometimes concentrated in the Golgi area, or at the plasma membrane." (45) . To our knowledge, there were no additional reports on the intracellular localization of LPHA reactivity in human neoplasms. However, in non-neoplastic mink lung type II alveolar cells, transfection of GNT-V produced multilamellar bodies of diverse sizes (100–2400 nm), conferring a vesicular phenotype on the cells (46) . The structures were LPHA positive, contained CD63 and LAMP-2, and their formation was autophagy dependent. These observations were of interest to us in light of recent findings from our laboratory where mouse melanoma cells with low GNT-V expression, when hybridized to normal mouse or human macrophages, showed increased GNT-V along with an LPHA-positive, vesicular phenotype, similar to that in macrophages. The vesicles appeared to be melanosome-containing autophagosomes known as coarse melanin (47, 48, 49, 50, 51, 52, 53, 54) . It thus seemed possible that these coarse melanin vesicles in hybrids, like the multilamellar bodies in mink alveolar lung cells, were induced by GNT-V and might therefore reflect increased ß1,6-branched N-glycans in the cells. Because coarse melanin was described previously in human melanoma (51 , 55 , 56) , and because little was known of GNT-V activity in melanoma, our study was first designed to determine the status of LPHA reactivity and its potential association with coarse melanin in histopathologic specimens of human melanomas. We were surprised to find that LPHA-positive coarse vesicles, with or without melanin, were a prominent feature of melanoma and, in an expanded study, a variety of other human tumors. Below are illustrative examples from a panel of 57 primary and metastatic human malignant melanomas, 62 additional human tumors of diverse origin, and a comparison of LPHA reactivity in primary and metastatic tumors from a single patient with renal cell carcinoma. Potential mechanisms and implications for metastatic progression are discussed.
|
MATERIALS AND METHODS |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
Lectin and Immunohistochemistry.
All lectin or immunostained melanoma tissue sections were first bleached by standard procedures to decolorize melanin (0.25% potassium permanganate and 1% oxalic acid, 20°C, 5' for cutaneous melanoma, or 15' for ocular melanoma). Bleaching was monitored with the light microscope to ensure complete decolorization. Nonmelanoma specimens were not bleached. Histological specimens were processed and stained by the immunoperoxidase technique through the Yale Dermatopathology Laboratory Service. Antibodies and lectins were as follows: HMB45 (antihuman melanosomal protein gp100; prediluted by company) was from DAKO. Antihuman CD63 was obtained from Novocastra Laboratories, Newcastle upon Tyne, United Kingdom (1:100 dilution) and was also a kind gift of Dr. M. Herlyn, Wistar Institute, Philadelphia, PA. (MAbME491; 1:20 dilution). Biotinylated LPHA, for detection of ß1,6-branched N-glycans, was from Vector Laboratories (Burlingame, CA). Azure blue plus S100 immunoperoxidase staining was used to distinguish melanophages from melanoma cells (57)
.
Scoring of Lectin and Immunostaining.
Tumor sections were first examined to distinguish between staining of cancer cells, melanophages, and other normal cells. An estimate of the percentage of cancer cells staining within a given section was then reached by agreement of two trained observers. Scoring was blinded such that each observer presented an independent score for a given section. Disparities were resolved by averaging the scores. Values assigned were O (no staining), 1 (1–25%), 2 (26–50%), 3 (51–75%), or 4 (76–100%). Statistical analyses were by the unpaired Student’s t test.
Colocalization of Melanin Granules.
This procedure was developed to investigate potential localization of lectin and immunostains to coarse melanin vesicles. Coarse melanin was first photographed in unstained tissue sections and microscope coordinates of the region were recorded. The sections were bleached, then lectin or immunostained via standard horseradish peroxidase techniques and counterstained with hematoxylin, and the same regions were located and again photographed.
N-Glycosidase F Assay for N-glycans.
N-glycosidase F (Peptide N-glycosidase; PNGase F; EC 3.5.1.52) for hydrolytic cleavage of N-glycans from glycopeptides, was obtained from Sigma/Aldrich Co. (St. Louis, MO). Procedures for N-glycosidase F treatment of fixed, paraffin-embedded sections were modified from Feige and Baird (58)
. Tissue sections were deparaffinized, rehydrated in PBS, and then immersed in buffer consisting of 50 mM Tris-Cl (pH 8.0), 150 mM NaCl, 0.02% sodium azide, 100 mg/ml p-methylsulfonyl fluoride, 1 mg/ml aprotinin, and 1% NP40, with or without N-glycosidase F (1:1000 dilution). Immersed slides were incubated at 37°C, 15 h, rinsed in H2O, and stained with biotinylated LPHA. Combining the glycosidase F procedure and bleaching caused extensive tissue damage. However, in the absence of bleaching, tissue was preserved, and results are thus presented for a renal carcinoma that was nonpigmented and did not require a bleaching step (Fig. 8C
, right).
|
|
RESULTS |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
. In primary melanomas, about half of the tumors (23 of 44) stained with LPHA over at least 75% of the tumor surface area; however, there was considerable heterogeneity, and the overall percentage of primary melanoma cells positive for LPHA varied between individual tumors from 0 to 100%. In contrast, metastases were more homogeneous, and 12 of 13 metastatic melanomas (lymph nodes, lungs, liver, and cutaneous) showed LPHA staining involving at least 75% of the tumor (Table 1)
. Where there was no statistical difference in LPHA staining between in situ and vertical phase melanomas (P = 0.481), the difference between either of these categories and metastatic melanomas was highly significant (metastatic versus in situ, P = 0.008; metastatic versus vertical phase, P = 0.0080). A small cohort of renal cell carcinomas yielded similar results. All three metastases (lymph node, lungs, and spine) from two patients stained homogeneously with LPHA, whereas the single primary tumor available showed only foci of LPHA-positive cells, comprising <25% of the tumor (below). In melanomas, CD63 staining of coarse vesicular structures closely paralleled that of LPHA; however, this was not the case in a variety of other neoplasms, where CD63 positivity was less common (Table 2)
. Examples of these findings are presented below.
|
|
shows one of the two malignant melanomas in situ out of 18 from this study that did not stain with LPHA (Fig. 1
; Table 1
). The H&E-stained slide (left) revealed melanized melanoma cells in the basal layer of the epidermis, denoted by the bar. Melanin in these tumor cells resembled that in normal melanocytes from this patient, exhibiting nuclear capping, and distribution in finely dispersed small granules. A sequential section was bleached to decolorize melanin and stained with LPHA (Fig. 1
, right). Tumor cells from the melanized region (bar) were negative for LPHA and throughout the tumor. Tumor cells were also negative for CD63 (data not shown). In other regions, melanophages stained with LPHA and served as positive staining controls for this tumor.
|
shows a second example of malignant melanoma in situ, in this case, a heavily pigmented tumor comprised of multiple intraepidermal nests with 100% of their cells positive for LPHA and CD63 (Fig. 2
, top row; Table 1
). Higher power views (Fig. 2
, bottom row, arrows) revealed coarse melanin, consisting of heterogeneous melanized vesicles and globules. After bleaching, LPHA and anti-CD63 stained similar coarse structures, and it is shown below in other melanoma cases that indeed these stains colocalized to coarse melanin (Figs. 6A–C)
. The tumor was surrounded and infiltrated with melanophages (m), also containing coarse melanin (Fig. 2
, bottom row, left). Melanophages stained strongly with LPHA (Fig. 2
, bottom row, center), but not CD63 (Fig. 2
, bottom row, right), and were in general more heavily melanized than melanoma cells (The melanin in melanophages was presumably attributable to phagocytosed melanoma cells.) Although melanoma cells and melanophages bore a strong resemblance, they were distinguished from one another by azure blue/S100 staining (Ref. 57
; data not shown) and by the large, pleomorphic nuclei characteristic of melanoma cells.
|
|
is a third example of malignant melanoma in situ, in this case, an amelanotic one with junctional and intraepidermal nests staining with LPHA (Fig. 3)
. The H&E stain (left) revealed a junctional nest of amelanotic melanoma cells. In sequential sections of the same region, this nest stained for LPHA (center), HMB45 (right), and CD63 (data not shown). Staining included, but was not restricted to, coarse vesicular structures (data not shown). Tumor cells immediately around the nest also stained with LPHA, although to a far less extent than those in the nest. About 50% of the cells of this tumor stained with LPHA (Table 1)
.
|
is an example of a malignant melanoma in vertical growth phase (Fig. 4)
. This deeply invasive (Clark’s level IV), melanoma was highly positive for LPHA, anti-CD63, and HMB45. The tumor was predominantly amelanotic, and melanized cells were rare. A focal area showing highest reactivity for all three stains was located in a specific region of nested amelanotic melanoma cells in the upper dermis (Fig. 4
, top row, arrows). High power views revealed that each of these stains was associated with coarse vesicles and globules (Fig. 4
, bottom row, arrows). Over 75% of this tumor stained with LPHA and CD63 (Table 1)
.
|
shows an amelanotic malignant melanoma metastasis to a lymph node, staining throughout with both LPHA and HMB45, while normal nodal tissue was negative for these stains. This metastasis was from the primary malignant melanoma shown in Fig. 4
. CD63 staining was not investigated because of insufficient material. A liver metastasis from the same patient also stained uniformly with LPHA, HMB45, and anti-CD63 (data not shown). Higher power views of both the lymph node and liver metastases from this patient revealed coarse vesicular staining throughout the tumors (data not shown), indistinguishable from that in cells of the primary tumor (c.f. Fig. 4
, bottom row).
|
. The tumor cells (t), but not normal tissue, stained uniformly with LPHA and anti-CD63 in a coarse vesicular fashion.
In a patient with ocular melanoma, a metastasis to the liver consisted of heavily melanized cells (Fig. 5C)
. The cells stained uniformly with LPHA and HMB45. Higher power views revealed coarse melanin and coarse vesicular staining patterns (data not shown). CD63 staining was not assessed in this case.
Colocalization of Coarse Melanin with Lectin and Immunostains.
Melanin could be used as a marker in unstained sections, thus enabling experiments to investigate immuno- and lectin-reactivity of individual coarse melanin vesicles. Coarse melanin was photographed in unstained sections, bleached, and stained with either LPHA, anti-CD63, or HMB45, and the same regions were then rephotographed. In all four melanomas examined in this fashion, the three stains consistently colocalized to coarse melanin vesicles, although LPHA stained additional cellular areas. The results are illustrated below for one of these tumors, a malignant melanoma in vertical growth phase. LPHA colocalized to coarse melanin structures in both melanoma cells (arrows) and melanophages (m) (Fig. 6A)
. In sequential sections, anti-CD63 (Fig. 6B)
and HMB45 (Fig. 6C)
also localized to coarse melanin in melanoma cells (arrows). Melanophages did not stain with CD63 and only sporadically with HMB45.
Peripheral Melanocytes.
Normal melanocytes peripheral to the tumors did not stain for LPHA or exhibit coarse melanin, and in general produced less melanin per cell than did LPHA-positive, melanized tumor cells (Fig. 6D)
.
Thus, colocalization studies determined for the first time that coarse melanin in melanoma cells is composed in part of ß1,6-branched oligosaccharides, lysosome/late endosome protein CD63, and melanosomal matrix protein, gp100. Furthermore, the melanin within coarse melanin-containing melanoma cells was in greater quantity per cell than melanin in normal melanocytes peripheral to the tumor.
Tumor Microarray.
To determine whether the LPHA-positive, vesicular phenotype might be expressed in tumors other than melanomas, we investigated a microarray panel of 58 primary human tumors, consisting of carcinomas of diverse origins, melanomas, and other tumors. Sequential sections of the microarray were stained with LPHA and anti-CD63 (Table 2)
. As with primary malignant melanomas (Table 1)
, there was considerable heterogeneity in the extent of LPHA staining, ranging from 0 to 100%; however, 55 of 58 tumors showed positive staining regions with LPHA. LPHA staining of these tumors was always, but not exclusively, associated with vesicles or globules of different shapes and sizes, as exemplified for eight different human carcinomas (Fig. 7
, arrows). It was also notable that 11 of 13 Hodgkin’s lymphomas in this panel showed positive LPHA staining over at least 75% of the tumor, again in a coarse vesicular fashion, indicating that this phenotype may be a general feature of Hodgkin’s lymphoma. CD63 staining of the tumor microarray was sporadic, with 44 of 58 tumors being negative, and only melanomas showing consistent staining, with 4 of 4 tumors positive over at least 75% of the area. Other tumors staining for CD63 were carcinoid (1 of 3), lymphoma (Hodgkin’s and non-Hodgkin’s; 4 of 16), mesothelioma (1 of 2), malignant fibrous histiocytoma (1 of 1), and carcinomas of the ovary (1 of 2), thyroid (1 of 2), and prostate (1 of 2; Table 2
).
|
, left). The eosinophilic cells stained for LPHA, but clear cells did not (Fig. 8A
, center). In addition, the eosinophilic cells displayed nuclei of various sizes, many of which were fragmented. Among the LPHA-positive, eosinophilic population were large, highly vesicular, spherical cells (Fig. 8A
, right, arrows). Although cells with this morphology were in the minority in the primary tumor, they were exclusively present in a fine needle aspirate of a metastasis to the lung (Fig. 8B)
. Likewise, a metastasis to the spine was uniformly populated with LPHA-positive, eosinophilic, vesicular cells similar to those in the primary renal cell carcinoma. LPHA-positive metastatic tumor cells filling a vessel within this metastasis are shown (Fig. 8C
, left and center). Higher power magnification demonstrated their vesicular nature and a coarse vesicular LPHA staining pattern (data not shown). Thus, it seemed that for this patient, LPHA-positive cells in the primary tumor were the source of metastases.
Glycosidase F.
When sections of the renal cell carcinoma metastasis to the spine shown above were treated with glycosidase F before LPHA addition, staining was largely abolished, indicating that the LPHA was specifically binding to N-glycans (Fig. 8C
, right). The same results were obtained with nine of nine glycosidase F-treated, sequential sections of this renal cell carcinoma. Glycosidase F treatment also strongly reduced LPHA staining in multiple sections of three of three melanomas tested; however, results with melanomas are not shown because combining the glycosidase F and the melanin bleaching procedures caused extensive tissue damage (see "Materials and Methods"). We conclude from these studies that the LPHA staining was largely associated with ß1,6-branched N-glycans.
|
DISCUSSION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
and 5A)
and renal cell carcinoma (Fig. 8A–C)
. In each case, LPHA-positive, vesicular cells were observed in the primary tumors that were morphologically identical to those in metastases, suggesting they were the source of metastatic cells in the primary tumor. It is thus interesting that Clark et al. (55)
observed previously that cells of melanoma metastases showed more morphological homogeneity than those of the primary tumor, yet specific nests of melanoma cells in primary tumors could be found that closely resembled those in metastases. Our results suggest that these cells were likely to have been the LPHA-positive, vesicular cells described herein.
The results raise several questions as to the origin of this phenotype and the mechanisms through which its expression might result in enhanced metastatic potential. GNT-V expression has been associated with several hallmarks of tumor progression: loss of decreased substrate adhesion, loss of contact inhibition, increased migration in vitro, and increased metastasis in vivo (40
, 42
, 43
, 53)
. It is also notable that highly motile macrophages and other myeloid cells employ ß1,6-branched polylactosamines with terminal Lewisx and Lewisa antigens for selectin binding during intravasation and systemic migration, as do some malignant cells in vitro (10
, 37, 38, 39)
. We demonstrated here that tumor-associated melanophages were indeed highly LPHA positive, and, interestingly, rich in LPHA-decorated, melanin-containing vesicles (in this case, phagolysosomes with melanin from phagocytosed melanoma cells; Fig. 2
). Thus, an LPHA-positive, vesicular phenotype was also characteristic of normal migratory cells, perhaps providing clues as to the relation between this phenotype and migration of malignant cells.
On the other hand, we also observed the LPHA-positive vesicular phenotype in nonmalignant tumors, such as leiomyoma (Table 2)
, and most recently in some pigmented cutaneous nevi.4
Similarly, Fernandes et al. (13)
, while showing a significant correlation between LPHA positivity in primary breast and colon cancers and poor survival, also reported LPHA-positive areas of nonmalignant epithelial hyperplasia in breast tissue and adenomatous polyps and villous adenomas in colon tissue. How might the expression of this phenotype in nonmalignant lesions be reconciled with the data that LPHA positivity is associated with tumor progression? One explanation could be that expression of the LPHA-positive phenotype per se is not sufficient to induce malignant transformation, e.g., when expressed in normal macrophages or hyperplastic lesions; rather, the genetic context in which this phenotype is expressed is a determining factor as to cellular behavior. By this view, GNT-V expression could play a causative role in tumor progression when expressed in certain neoplastic cells but not in hyperplastic cells where, e.g., mitosis is only partially deregulated.
Regarding the origin of this phenotype, some cases herein revealed evidence for clonal generation of LPHA-positive, vesicular cells, as seen in solitary nests within melanoma in situ (Fig. 3)
. This suggested that the phenotype might have arisen stochastically in single progenitor cells within the tumor. Furthermore, work of Hariri et al. (46)
raised the possibility that the vesicular phenotype might be induced solely by GNT-V. GNT-V transfection into mink lung type II alveolar cells induced formation of autophagy-dependent, LPHA- and CD63-positive multilamellar bodies (46)
. Thus, in the tumors described herein, elevated GNT-V might have been the underlying cause of the vesicular phenotype; however, the mechanisms through which GNT-V-expressing cells are generated in tumors are not understood.
GNT-V expression has been induced by a variety of factors, including oncogenes such as src, her-neu, H-ras, v-sis, and regulated through ras-raf-ets pathways (59, 60, 61) . The protein kinase C and phosphatidylinositol 3-kinase-protein kinase B signaling pathways were also shown to stimulate GNT-V activity (62 , 63) . In studies from our lab, experimental macrophage-melanoma fusion hybrids expressed high GNT-V activity concomitant with increased chemotactic motility in vitro and metastatic potential in vivo (47, 48, 49, 50, 51, 52, 53, 54) . These hybrids expressed an LPHA-positive, vesicular phenotype remarkably similar to that of the tumors shown herein (52, 53, 54) . Regarding the possibility of hybridization as an initiating event in GNT-V expression, it should be noted that there is considerable precedent for spontaneous hybridization in animal tumor models (51 , 52) , and horizontal transfer of oncogenes during phagocytosis of tumor cells in vitro has been demonstrated (64, 65, 66) . Indeed, it was the combination of macrophage-like glycosylation and production of coarse melanin in experimental macrophage/melanoma hybrids that motivated this current study in human cancers (47, 48, 49, 50, 51, 52, 53, 54) .
A major diagnostic feature of primary cutaneous melanoma is the presence of heterogeneous pigmentation, often with prominent hyper and/or hypomelanotic regions. Our studies revealed that the hypermelanotic regions were largely comprised of melanoma cells and melanophages with LPHA-positive coarse melanin, and it was these two cell types that provided the underlying basis for hypermelanization of the tumors (Fig. 2)
. As assessed visually, melanoma cells in hypermelanotic regions typically produced more total melanin per cell than did normal junctional peripheral melanocytes, which did not produce coarse melanin, and were LPHA and CD63 negative. Thus, LPHA positivity was associated with both increases in the quantity and differences in the packaging of the tumor melanin.
The LPHA-positive coarse vesicles and globules shown here appear to be the same as those noted previously in primary carcinomas of the breast and colon (13)
, and, from earlier studies of coarse melanin (below), are likely to be autophagosomal. In mammalian cells, autophagosomes are formed during macroautophagy, the main cellular mechanism for degradation of intracellular macromolecules and organelles–processes that play an important role in the control of cellular protein metabolism and growth (67, 68, 69)
. Thus, the results imply a role for macroautophagy in the LPHA-positive, vesicular phenotype, although the implications of this for cancer biology are as yet unclear. It is interesting therefore that coarse melanin is also thought to be autophagosomal (70, 71, 72, 73)
. Coarse melanin in melanoma was first associated with "animal type" malignant melanoma in horses in 1832 and humans in 1925 (see 56
). Clark et al. (55)
described coarse melanin as a "major melanosomal abnormality primarily associated with cells in vertical growth phase melanomas." The melanoma cells showed "numerous granular organelles, 250–500 nm in width, with melanin deposited in a coarsely granular fashion, commonly seen in the vertical growth phase of superficial spreading melanoma, in nodular melanoma, and in metastatic melanoma." Crowson et al. (56)
described coarse melanin in human melanomas as "often irregularly disposed, manifesting large globular deposits," "obscuring the nucleus, making melanoma cells difficult to distinguish from melanophages." Of particular interest to our findings, Cesarini and Clark reported similar coarse vesicles but lacking melanin in amelanotic melanomas (see Ref. 55
). It now seems likely that these amelanotic vesicles were also autophagosomal and belonged to the same class of LPHA-, CD63-, and HMB45-positive amelanotic vesicles shown herein (Fig. 4)
.
In conclusion, we describe a new phenotype commonly expressed by melanomas and a variety of other human neoplasms: expression of LPHA-positive coarse vesicles rich in ß1,6-branched oligosaccharides. In melanomas, the vesicles also contained CD63 and gp100 and, in pigmented regions, comprised coarse melanin. Some amelanotic melanoma cells also displayed LPHA-, anti-CD63-, and HMB45-positive coarse vesicles but lacking melanin. Coarse melanin from both melanoma cells and melanophages appeared to account for the hypermelanotic areas of primary cutaneous melanomas. Although such vesicles were found in nearly all of a variety of neoplasms examined, they were most prominently expressed in metastases, suggesting that LPHA-positive vesicular cells in primary tumors were at least in part responsible for tumor progression. The observations on LPHA-positive coarse vesicular cells raise many questions as to their origin and mechanistic relationship to cancer that are beyond the scope of these initial observations. Our future experiments are directed toward an expansion of the histopathologic studies and investigations as to the molecular genetic mechanisms responsible for generating this interesting phenotype.
|
ACKNOWLEDGMENTS |
|---|
|
FOOTNOTES |
|---|
1 Supported by a gift from Vion Pharmaceuticals and a grant from the Yale Skin Diseases Research Core Center (2 P30 AR41942–06A1). 
2 To whom requests for reprints should be addressed, at Department of Dermatology, Yale University School of Medicine, New Haven, CT 06520-8059. Phone: (203) 785-4411; Fax: (203) 785-7637; E-mail: john.pawelek{at}yale.edu
3 The abbreviations used are: GlcNAc, N-acetylglucoseamine; LHPA, leukocytic phytohemagglutinin.
4 Handerson, T. and Pawelek, J., unpublished observations.
Received 1/31/03. Revised 4/14/03. Accepted 7/18/03.
|
REFERENCES |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
-(1, 3)-fucosyltransferases which synthesize sialy Lex and silyl Lea, the carbohydrate ligands for E- and P-selectins, in human malignant cell lines. Cancer Res., 53: 5559-5565, 1993.1, 3-fucosyltransferase in association with malignancy. Clin. Exp. Metastasis, 18: 605-610, 2001.
-mannoside ß1, 6 N-acetylglucosaminyltransferase is an early event in hepatocarcinogenesis. Int. J. Cancer, 91: 631-637, 2001.[Medline]
1–3)GlcNAc (X determinant) expressed in HL-60 cells on both glycolipid and glycoprotein molecules. Blood, 62: 1022-1026, 1983.This article has been cited by other articles:
|
|
 |
|
  Y. Kariya, R. Kato, S. Itoh, T. Fukuda, Y. Shibukawa, N. Sanzen, K. Sekiguchi, Y. Wada, N. Kawasaki, and J. Gu N-Glycosylation of Laminin-332 Regulates Its Biological Functions: A NOVEL FUNCTION OF THE BISECTING GlcNAc J. Biol. Chem., November 28, 2008; 283(48): 33036 - 33045. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Vagin, E. Tokhtaeva, I. Yakubov, E. Shevchenko, and G. Sachs Inverse Correlation between the Extent of N-Glycan Branching and Intercellular Adhesion in Epithelia: CONTRIBUTION OF THE Na,K-ATPase 1 SUBUNIT J. Biol. Chem., January 25, 2008; 283(4): 2192 - 2202. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. H.M. de Melo, D. Butera, R. S. Medeiros, L. N. d. S. Andrade, S. Nonogaki, F. A. Soares, R. A. Alvarez, A. M. Moura da Silva, and R. Chammas Biological Applications of a Chimeric Probe for the Assessment of Galectin-3 Ligands J. Histochem. Cytochem., October 1, 2007; 55(10): 1015 - 1026. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Zhao, T. Nakagawa, S. Itoh, K.-i. Inamori, T. Isaji, Y. Kariya, A. Kondo, E. Miyoshi, K. Miyazaki, N. Kawasaki, et al. N-Acetylglucosaminyltransferase III Antagonizes the Effect of N-Acetylglucosaminyltransferase V on {alpha}3beta1 Integrin-mediated Cell Migration J. Biol. Chem., October 27, 2006; 281(43): 32122 - 32130. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Ishimura, T. Takahashi, H. Nakagawa, S.-I. Nishimura, Y. Arai, Y. Horikawa, T. Habuchi, E. Miyoshi, A. Kyan, S. Hagisawa, et al. N-Acetylglucosaminyltransferase V and {beta}1-6 Branching N-Linked Oligosaccharides Are Associated with Good Prognosis of Patients with Bladder Cancer Clin. Cancer Res., April 15, 2006; 12(8): 2506 - 2511. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. F. Siddiqui, J. Pawelek, T. Handerson, C.-Y. Lin, R. B. Dickson, D. L. Rimm, and R. L. Camp Coexpression of {beta}1,6-N-Acetylglucosaminyltransferase V Glycoprotein Substrates Defines Aggressive Breast Cancers with Poor Outcome Cancer Epidemiol. Biomarkers Prev., November 1, 2005; 14(11): 2517 - 2523. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Lajoie, G. Guay, J. W. Dennis, and I. R. Nabi The lipid composition of autophagic vacuoles regulates expression of multilamellar bodies J. Cell Sci., May 1, 2005; 118(9): 1991 - 2003. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Handerson, R. Camp, M. Harigopal, D. Rimm, and J. Pawelek {beta}1,6-Branched Oligosaccharides Are Increased in Lymph Node Metastases and Predict Poor Outcome in Breast Carcinoma Clin. Cancer Res., April 15, 2005; 11(8): 2969 - 2973. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Cancer Research | Clinical Cancer Research |
| Cancer Epidemiology Biomarkers & Prevention | Molecular Cancer Therapeutics |
| Molecular Cancer Research | Cancer Prevention Research |
| Cancer Prevention Journals Portal | Cancer Reviews Online |
| Annual Meeting Education Book | Meeting Abstracts Online |
