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Pattern of endogenous lectins of a human sarcoma (Ewing's sarcoma) reveals differences to human normal tissues and tumors of epithelial and germ cell origin
139
Cancer Letters, 31 (1986) 139-146 Elsevier Scientific Publishers Ireland Ltd.
PATTERN OF ENDOGENOUS LECTINS OF A HUMAN SARCOMA (EWING’S SARCOMA) REVEALS DIFFERENCES To HUMAN NORMAL TISSUES AND TUMORS OF EPITHELIAL AND GERM CELL ORIGIN
HANSJ. GARIUSa** , REINHILD ENGELHARDTa, FRIEDRICH CRAMER*
DAVID J. SARTORISb and
*Max-Planck-Institut fiir experimentelle Medizin, Abteilung Chemie, Hermann-ReinStrasse 3, D-3400 Giittingen (F. R.G.) and b University of California, San Diego, Medical Center, Department of Radiology, San Diego, CA 92103 (U.S.A.) (Received 16 September 1985) (Revised version received 13 February 1986) (Accepted 10 March 1986)
SUMMARY
A human sarcoma, Ewing’s sarcoma, contains activities of endogenous lectins. Fractionation of salt and detergent extracts by affinity chromatography on columns with immobilized sugars or glycoproteins results in the pattern of endogenous lectins for OL-and @-galactosides, ol-mannosyland cu-fucosyl-moieties. Whereas some lectins are known from normal, non-malignant human tissues or from a human epithelial tumor or a human germ cell tumor, a Ca”-independent (Y- and fl-galactoside-binding protein at apparent molecular weight of 58 kilodaltons has so far not been characterized from any human source. The patterns for the tumors and human normal tissues reveal various differences in comparison between each other. These differences, documented for the first human sarcoma, human tumors of different hi&genetic lineage and normal tissues are a first step to a h&in-based diagnosis and therapy of certain human cancer types.
INTRODUCTION
The structure and composition of carbohydrate moieties in glycoconjugates (glycoproteins and glycolipids) are important carriers of information for recognitive processes. Interaction of glycoconjugates with carbohydratebinding proteins like lectins is known to take part in recognitive processes as regulation of plasma glycoprotein metabolism, cell cohesiveness, opsonization and phagocytosis [ 1,121. Whereas much attention has been paid to the *To whom all correspondence
should be addressed.
01986 Elsevier Scientific Publishers Ireland Ltd. 0304-3835/86/$03.50 Published and Printed in Ireland
140
alteration of glycoconjugates upon malignant transformation [3,7,14], the biochemical characterization of endogenous tumor lectins has only recently been initiated with analysis of two types of human tumors [ 5,6]. Here we present the pattern of endogenous lectins for the first human sarcoma, Ewing’s sarcoma. It is the most common primary small cell sarcoma of bone accounting for approximately 10% of all primary malignant bone tumors in the population and has a striking propensity to develop distant metastases [13]. Since tumor lectins may serve as tumor markers and a lectin-based drug targeting has been shown to be feasible in a model system [lo] , description of such patterns is a step of potential clinical importance. MATERIALS
AND METHODS
Tumor material was obtained from the Cancer Center of the University of California, San Diego, and normal tissue from the pathological department in Giittingen. Typically, frozen and thawed tumor material (3.5 g) or bone marrow (7 g) were blended in a Waring blender with 100 ml of cold acetone for 1 min and processed as described [ 5,6] . Briefly, the resulting 0.8 g of acetone powder was extracted twice with 100 ml of salt extraction buffer (20 mM Tris-HCl (pH 7.8) containing 0.2 M NaCl, 1 mM dithiothreitol and 0.1 mM phenylmethanesulfonyl fluoride) and the combined extracts were brought to a final concentration of 25 mM CaCl,, 0.5% Triton X-100 and 1.25 M NaCl. The insoluble pellet of the first extraction was subsequently extracted twice with 80 ml detergent extraction buffer (20 mM Tris-HCl (pH 7.8) containing 2% Triton X-100,0.4 M KCI, 1 mM dithiothreitol and 0.1 mM phenylmethanesulfonyl fluoride). The supernatants were combined and brought to a final concentration of 25 mM CaCl,. Each extract was applied separately to one set of 5 columns (0.5 X 16 cm lactose-, asialofetuin-, melibiose-, and mannan-Sepharose 4B; 0.5 X 12 cm fucose-Sepharose 4B), prepared as described [5,6]. The carbohydrate binding proteins were eluted by EDTA and, after re-equilibration, by the appropriate sugar and affinity chromatography was repeated on 3-ml columns as described [ 5,6]. Analytical procedures and further ascertainment of lectin specificity with fluoresceinylated, glycosylated bovine serum albumin have been described in detail elsewhere [4-6]. RESULTS
Resins with different immobilized sugars or glycoproteins are used to isolate carbohydrate-binding proteins with specificities for fi-galactosides (lactose and the more complex carbohydrate structure of asialofetuin, exposing a terminal galactose), a-galactosides (melibiose), cu-mannosyl(mannan) and cu-fucosyl-moieties (fucose). The pattern is further divided into categories of dependence on Ca2+-ions for binding activity (elution by EDTA for Ca”-dependent carbohydrate-binding proteins and subsequently by specific sugar for Ca”-independent carbohydrate-binding
141
a
b
C
d
e
f
g
Fig. 1. Polyacrylamide gel electrophoresis in the presence of 0.1% sodium dodecyl sulfate of endogenous lectins from a human Ewing’s sarcoma. A tenth of a typical preparation is applied per gel. Elution with EDTA after application of salt extracts from immobilized lactose (a), asialofetuin (b) and mannan (c). Elution with specific sugar after application of salt extracts from immobilized lactose (d), asialofetuin (e) and melibiose (f) and after application of detergent extracts from immobilized lactose (g). In all other fractions no protein was detected after application of up to one half of a typical preparation. Standards are indicated by bars: phosphorylase b (97 kilodaltons), bovine serum albumin (66 kilodaltons), ovalbumin (44 kilodaltons), glyceraldehyde-3-phosphate dehydrogenase (36 kilodaltons), carbonic anhydrase (29 kilodaltons) and lysozyme (14.3 kilodaltons).
proteins) and into categories of dependence on salt or detergent extraction, corresponding to soluble cytoplasmic or extracellular and extractable membrane proteins. Two different proteins with specificity to p-galactosides and mannose, respectively, exhibit clear intrinsic requirement for Ca’+-ions. They are only present after sugar elution in considerably smaller amount. Sugar elution results in purification of additional strong protein bands at apparent molecular weights of 58 kilodaltons and 54 kilodaltons with specificity to (II-and /3-galactosides and 14 kilodaltons with specificity to p-galactosides (Fig. 1). The latter protein is the only band that can be isolated from salt and detergent extracts. Carbohydrate-binding proteins with specificity to a-fucosyl-moieties are not detectable. Analysis of human bone marrow reveals qualitative differences in comparison (Fig. 2). It contains fucosebinding proteins with and without Ca*‘dependence. But it lacks a Ca*‘independent (Y- and p-galactoside-binding protein at apparent molecular weight of 58 kilodaltons. Furthermore no band at apparent molecular weight of 31 kilodaltons after EDTA elution is detectable.
142
4
*”
>j
__,
ab
)
c
d
l*:
ef
g
h
i’j
Fig. 2. Polyacrylamide gel electrophoresis in the presence of 0.1% sodium dodecyl sulfate of endogenous lectins from human bone marrow. Elution with EDTA after application of salt extracts from immobilized lactose (a), asialofetuin (b), melibiose (c), mannan (d) and fucose (e) and after application of detergent extracts from immobilized lactose (f), asialofetuin (g), melibiose (h) and mannan (i). Elution with specific sugar after application of salt extracts from immobilized lactose (j), melibiose (k) and fucose (1) and after application of detergent extracts from immobilized lactose (m).
The isolated carbohydrate-binding proteins rebind to columns of the corresponding specificity, are not eluted by non-specific sugars (sucrose) and bind to the corresponding neoglycoproteins (lactosylated, melibiosylated or marmosylated bovine serum albumin) in the absence of inhibitors (specific sugar at 0.3 M). They can agglutinate trypsin-treated, glutaraldehyde-fixed rabbit erythrocytes at con centrations between 2 and 3.5 pg/ml. Tests of these fractions for enzymatic activities such as glycosidases or glycosyltransferases were negative. Thus, these carbohydrate-binding proteins can be defined as endogenous lectins. DISCUSSION
The lectin pattern of Ewing’s sarcoma, the first type of human sarcoma investigated so far, differs qualitatively from the pattern of two other human tumors and human bone marrow (Table 1). No similar endogenous lectin with specificity to a- and P-galactosides has been detected at apparent molecular weight of 58 kilodaltons, whereas the other lectins of the sarcoma have been isolated from the human epithelial or germ cell tumor. In comparison to the tumors of epithelial or germ cell origin, respectively, several lectins with specificity to (Y-and P-galactosides, cu-mannosyl- and &ucosylmoieties are undetectable in the sarcoma (Table 1). The pattern for bone marrow reveals significant qualitative differences to all tumors. Further
29
29
29
29
29
29 29
70 35
29
31
29
54,29 28
29,28 -
4543
31
31
-
Melibiose
29
29
31
31
31
31
29
31
Mannan
-
110,54 26
70 62
62
31 31
70
-
54 29 14 14
-
-
-
-
14 64,35 16,14
-
14 64
-
54
Asialofetuin
14 35
31,29 14 14 35
58.54
Lactose
Sugar ~_
54 31 29 -
64
64
-
-
31,29
58,54
Melibiose
-
-
-
-
68
-
-
Mannan
-
60,54 50,29
62
-
-
-
-
Fucose
_.__ _...__-- ..-.----.
The extraction and elution conditions permit a dividing of the lectin pattern into salt extractable (first line) or detergent extractable (second line), Ca*+-dependent (elution by EDTA) or Cal+ -independent (elution by specific sugar) lectins. aApparent molecular weight is given in thousands. bFrom Ref. 6. CFrom Ref. 5.
Bone marrow
tumor ( apudoma)c
Epithelial
31
31
31
Embryonic
carcinomab
29
31
Asialofetuin
29
31
Lactose
EDTA Fucose
HUMAN TUMORS
Molecular weight with the following elutio&
sarcoma
Ewing’s
Tumor type
LECI’IN PATTERN OF THREE DIFFERENT
TABLE 1
-_
_
144
comparisons are possible to other human tissues. The common p-galactosidespecific lectin at apparent molecular weight of 14 kilodaltons, but no other lectin with this specificity is present in human lung [ll] , only one lectin with specificity to galactosides at apparent molecular weight of 41 kilodaltons is present in human liver [2] and Ca”-dependent mannose-specific proteins at apparent molecular weights of 29 kilodaltons and 31 kilodaltons are present in human liver [15] and serum [9]. It is noteworthy that alveolar macrophages from rat contain a lectin with specificity of fucose and galactose at apparent molecular weight of 52 kilodaltons [8]. The reported differences in the pattern of endogenous lectins between a human sarcoma, human epithelial and germ cell tumors and normal tissues are a prerequisite for the potential use of this class of proteins in diagnosis and therapy. It may also be of importance for the understanding of cellular interactions in tumor progression and metastasis, mediated by the interplay of endogenous lectins and their sugar receptors. ACKNOWLEDGEMENT
We would like to thank E. Graeser, D. Resnick and R. Sobol for help and advice. REFERENCES
4
5 6
7 8
9 10
Barondes, S.H. (1981) Lectins: their multiple endogenous functions. Annu. Rev. Biochem., 50, 207-231. Baenzinger, J.U. and Maynard, Y. (1980) Human hepatic lectin. J. Biol. Chem., 255, 4607-4613. Feizi, T. (1985) Demonstration by monoclonal antibodies that carbohydrate structures of glycoproteins and glycolipids are onto-developmental antigens. Nature, 314, 53-57. Gabius, H.-J., Engelhardt, R., Rehm, S. and Cramer, F. (1984) Biochemical characterization of endogenous carbohydrate-binding proteins from spontaneous murine rhabdomyosarcoma, mammary adenocarcinoma, and ovarian teratoma. J. Natl. Cancer Inst., 73, 1349-1357. Gabius, H.J., Engelhardt, R., Cramer, F., Biitge, R. and Nagel, G.A. (1985) Pattern of endogenous lectins in a human epithelial tumor. Cancer Res., 45, 283-287. Gabius, H.-J., Engelhardt, R., Casper, J., Reile, D., Schumacher, S., Schmoll, H.-J., Gaupner, G. and Cramer, F. (1985) Cell surface lectins of transplantable human teratocarcinoma cells: purification of a new mannan-specific endogenous lectin. Tumour Biol., 6, 145-156. Hakomori, S.-I. (1985) Aberrant glycosylation in cancer cell membranes as focused on glycolipids: overview and perspectives. Cancer Res., 45, 2405-2414. Lehrman, M.A., Haltiwanger, R.S., Eckhardt, A.E. and Hill, R.L. (1984) Carbohydrate-binding protein (lectins) in rat macrophages. In: Progress in Bioorganic Chemistry and Molecular Biology, pp. 141-150. Editor: Y.A. Ovchinikov. Elsevier, Amsterdam. Kawasaki, N., Kawasaki, T. and Yamashina, I. (1983) Isolation and characterization of a mannan-binding protein from human serum. J. Biochem., 94, 937-947. Monsigny, M., Roche, A.-C. and Midoux, P. (1984) Uptake of neoglycoproteins via membrane lectin(s) of L1210 cells evidenced by quantitative flow cytofluorometry and drug targeting. Biol. Cell, 51, 187-196.
145
11 Powell, 12 13
14 15
J.T. (1980) Purification and properties of lung lectins. Biochem. J., 187, 123-129. Sharon, N. and Lis, H. (1982) Glycoproteins: research booming on long-ignored ubiquitous compounds. Mol. Cell. Biochem., 42, 167-187. Simone, J.V., Cassady, J.R. and Filler, R.M. (1982) Cancers of childhood. In: Cancer: principles and Practice of Oncology, pp. 1254-1330. Editors: J.T. DeVita, Jr., S. Hellman and S.A. Rosenberg. J.B. Lippincott Co., Philadelphia. Smets, L.A. and Van Beek, W.P. (1984) Carbohydrates of the tumor cell surface. Biochim. Biophys. Acta, 738, 237-249. Wild, J., Robinson, D. and Winchester, B. (1983) Isolation of mannose-binding proteins from human and rat liver. Biochem. J., 210, 167-174.
Cancer Letters, 31 (1986) 139-146 Elsevier Scientific Publishers Ireland Ltd.
PATTERN OF ENDOGENOUS LECTINS OF A HUMAN SARCOMA (EWING’S SARCOMA) REVEALS DIFFERENCES To HUMAN NORMAL TISSUES AND TUMORS OF EPITHELIAL AND GERM CELL ORIGIN
HANSJ. GARIUSa** , REINHILD ENGELHARDTa, FRIEDRICH CRAMER*
DAVID J. SARTORISb and
*Max-Planck-Institut fiir experimentelle Medizin, Abteilung Chemie, Hermann-ReinStrasse 3, D-3400 Giittingen (F. R.G.) and b University of California, San Diego, Medical Center, Department of Radiology, San Diego, CA 92103 (U.S.A.) (Received 16 September 1985) (Revised version received 13 February 1986) (Accepted 10 March 1986)
SUMMARY
A human sarcoma, Ewing’s sarcoma, contains activities of endogenous lectins. Fractionation of salt and detergent extracts by affinity chromatography on columns with immobilized sugars or glycoproteins results in the pattern of endogenous lectins for OL-and @-galactosides, ol-mannosyland cu-fucosyl-moieties. Whereas some lectins are known from normal, non-malignant human tissues or from a human epithelial tumor or a human germ cell tumor, a Ca”-independent (Y- and fl-galactoside-binding protein at apparent molecular weight of 58 kilodaltons has so far not been characterized from any human source. The patterns for the tumors and human normal tissues reveal various differences in comparison between each other. These differences, documented for the first human sarcoma, human tumors of different hi&genetic lineage and normal tissues are a first step to a h&in-based diagnosis and therapy of certain human cancer types.
INTRODUCTION
The structure and composition of carbohydrate moieties in glycoconjugates (glycoproteins and glycolipids) are important carriers of information for recognitive processes. Interaction of glycoconjugates with carbohydratebinding proteins like lectins is known to take part in recognitive processes as regulation of plasma glycoprotein metabolism, cell cohesiveness, opsonization and phagocytosis [ 1,121. Whereas much attention has been paid to the *To whom all correspondence
should be addressed.
01986 Elsevier Scientific Publishers Ireland Ltd. 0304-3835/86/$03.50 Published and Printed in Ireland
140
alteration of glycoconjugates upon malignant transformation [3,7,14], the biochemical characterization of endogenous tumor lectins has only recently been initiated with analysis of two types of human tumors [ 5,6]. Here we present the pattern of endogenous lectins for the first human sarcoma, Ewing’s sarcoma. It is the most common primary small cell sarcoma of bone accounting for approximately 10% of all primary malignant bone tumors in the population and has a striking propensity to develop distant metastases [13]. Since tumor lectins may serve as tumor markers and a lectin-based drug targeting has been shown to be feasible in a model system [lo] , description of such patterns is a step of potential clinical importance. MATERIALS
AND METHODS
Tumor material was obtained from the Cancer Center of the University of California, San Diego, and normal tissue from the pathological department in Giittingen. Typically, frozen and thawed tumor material (3.5 g) or bone marrow (7 g) were blended in a Waring blender with 100 ml of cold acetone for 1 min and processed as described [ 5,6] . Briefly, the resulting 0.8 g of acetone powder was extracted twice with 100 ml of salt extraction buffer (20 mM Tris-HCl (pH 7.8) containing 0.2 M NaCl, 1 mM dithiothreitol and 0.1 mM phenylmethanesulfonyl fluoride) and the combined extracts were brought to a final concentration of 25 mM CaCl,, 0.5% Triton X-100 and 1.25 M NaCl. The insoluble pellet of the first extraction was subsequently extracted twice with 80 ml detergent extraction buffer (20 mM Tris-HCl (pH 7.8) containing 2% Triton X-100,0.4 M KCI, 1 mM dithiothreitol and 0.1 mM phenylmethanesulfonyl fluoride). The supernatants were combined and brought to a final concentration of 25 mM CaCl,. Each extract was applied separately to one set of 5 columns (0.5 X 16 cm lactose-, asialofetuin-, melibiose-, and mannan-Sepharose 4B; 0.5 X 12 cm fucose-Sepharose 4B), prepared as described [5,6]. The carbohydrate binding proteins were eluted by EDTA and, after re-equilibration, by the appropriate sugar and affinity chromatography was repeated on 3-ml columns as described [ 5,6]. Analytical procedures and further ascertainment of lectin specificity with fluoresceinylated, glycosylated bovine serum albumin have been described in detail elsewhere [4-6]. RESULTS
Resins with different immobilized sugars or glycoproteins are used to isolate carbohydrate-binding proteins with specificities for fi-galactosides (lactose and the more complex carbohydrate structure of asialofetuin, exposing a terminal galactose), a-galactosides (melibiose), cu-mannosyl(mannan) and cu-fucosyl-moieties (fucose). The pattern is further divided into categories of dependence on Ca2+-ions for binding activity (elution by EDTA for Ca”-dependent carbohydrate-binding proteins and subsequently by specific sugar for Ca”-independent carbohydrate-binding
141
a
b
C
d
e
f
g
Fig. 1. Polyacrylamide gel electrophoresis in the presence of 0.1% sodium dodecyl sulfate of endogenous lectins from a human Ewing’s sarcoma. A tenth of a typical preparation is applied per gel. Elution with EDTA after application of salt extracts from immobilized lactose (a), asialofetuin (b) and mannan (c). Elution with specific sugar after application of salt extracts from immobilized lactose (d), asialofetuin (e) and melibiose (f) and after application of detergent extracts from immobilized lactose (g). In all other fractions no protein was detected after application of up to one half of a typical preparation. Standards are indicated by bars: phosphorylase b (97 kilodaltons), bovine serum albumin (66 kilodaltons), ovalbumin (44 kilodaltons), glyceraldehyde-3-phosphate dehydrogenase (36 kilodaltons), carbonic anhydrase (29 kilodaltons) and lysozyme (14.3 kilodaltons).
proteins) and into categories of dependence on salt or detergent extraction, corresponding to soluble cytoplasmic or extracellular and extractable membrane proteins. Two different proteins with specificity to p-galactosides and mannose, respectively, exhibit clear intrinsic requirement for Ca’+-ions. They are only present after sugar elution in considerably smaller amount. Sugar elution results in purification of additional strong protein bands at apparent molecular weights of 58 kilodaltons and 54 kilodaltons with specificity to (II-and /3-galactosides and 14 kilodaltons with specificity to p-galactosides (Fig. 1). The latter protein is the only band that can be isolated from salt and detergent extracts. Carbohydrate-binding proteins with specificity to a-fucosyl-moieties are not detectable. Analysis of human bone marrow reveals qualitative differences in comparison (Fig. 2). It contains fucosebinding proteins with and without Ca*‘dependence. But it lacks a Ca*‘independent (Y- and p-galactoside-binding protein at apparent molecular weight of 58 kilodaltons. Furthermore no band at apparent molecular weight of 31 kilodaltons after EDTA elution is detectable.
142
4
*”
>j
__,
ab
)
c
d
l*:
ef
g
h
i’j
Fig. 2. Polyacrylamide gel electrophoresis in the presence of 0.1% sodium dodecyl sulfate of endogenous lectins from human bone marrow. Elution with EDTA after application of salt extracts from immobilized lactose (a), asialofetuin (b), melibiose (c), mannan (d) and fucose (e) and after application of detergent extracts from immobilized lactose (f), asialofetuin (g), melibiose (h) and mannan (i). Elution with specific sugar after application of salt extracts from immobilized lactose (j), melibiose (k) and fucose (1) and after application of detergent extracts from immobilized lactose (m).
The isolated carbohydrate-binding proteins rebind to columns of the corresponding specificity, are not eluted by non-specific sugars (sucrose) and bind to the corresponding neoglycoproteins (lactosylated, melibiosylated or marmosylated bovine serum albumin) in the absence of inhibitors (specific sugar at 0.3 M). They can agglutinate trypsin-treated, glutaraldehyde-fixed rabbit erythrocytes at con centrations between 2 and 3.5 pg/ml. Tests of these fractions for enzymatic activities such as glycosidases or glycosyltransferases were negative. Thus, these carbohydrate-binding proteins can be defined as endogenous lectins. DISCUSSION
The lectin pattern of Ewing’s sarcoma, the first type of human sarcoma investigated so far, differs qualitatively from the pattern of two other human tumors and human bone marrow (Table 1). No similar endogenous lectin with specificity to a- and P-galactosides has been detected at apparent molecular weight of 58 kilodaltons, whereas the other lectins of the sarcoma have been isolated from the human epithelial or germ cell tumor. In comparison to the tumors of epithelial or germ cell origin, respectively, several lectins with specificity to (Y-and P-galactosides, cu-mannosyl- and &ucosylmoieties are undetectable in the sarcoma (Table 1). The pattern for bone marrow reveals significant qualitative differences to all tumors. Further
29
29
29
29
29
29 29
70 35
29
31
29
54,29 28
29,28 -
4543
31
31
-
Melibiose
29
29
31
31
31
31
29
31
Mannan
-
110,54 26
70 62
62
31 31
70
-
54 29 14 14
-
-
-
-
14 64,35 16,14
-
14 64
-
54
Asialofetuin
14 35
31,29 14 14 35
58.54
Lactose
Sugar ~_
54 31 29 -
64
64
-
-
31,29
58,54
Melibiose
-
-
-
-
68
-
-
Mannan
-
60,54 50,29
62
-
-
-
-
Fucose
_.__ _...__-- ..-.----.
The extraction and elution conditions permit a dividing of the lectin pattern into salt extractable (first line) or detergent extractable (second line), Ca*+-dependent (elution by EDTA) or Cal+ -independent (elution by specific sugar) lectins. aApparent molecular weight is given in thousands. bFrom Ref. 6. CFrom Ref. 5.
Bone marrow
tumor ( apudoma)c
Epithelial
31
31
31
Embryonic
carcinomab
29
31
Asialofetuin
29
31
Lactose
EDTA Fucose
HUMAN TUMORS
Molecular weight with the following elutio&
sarcoma
Ewing’s
Tumor type
LECI’IN PATTERN OF THREE DIFFERENT
TABLE 1
-_
_
144
comparisons are possible to other human tissues. The common p-galactosidespecific lectin at apparent molecular weight of 14 kilodaltons, but no other lectin with this specificity is present in human lung [ll] , only one lectin with specificity to galactosides at apparent molecular weight of 41 kilodaltons is present in human liver [2] and Ca”-dependent mannose-specific proteins at apparent molecular weights of 29 kilodaltons and 31 kilodaltons are present in human liver [15] and serum [9]. It is noteworthy that alveolar macrophages from rat contain a lectin with specificity of fucose and galactose at apparent molecular weight of 52 kilodaltons [8]. The reported differences in the pattern of endogenous lectins between a human sarcoma, human epithelial and germ cell tumors and normal tissues are a prerequisite for the potential use of this class of proteins in diagnosis and therapy. It may also be of importance for the understanding of cellular interactions in tumor progression and metastasis, mediated by the interplay of endogenous lectins and their sugar receptors. ACKNOWLEDGEMENT
We would like to thank E. Graeser, D. Resnick and R. Sobol for help and advice. REFERENCES
4
5 6
7 8
9 10
Barondes, S.H. (1981) Lectins: their multiple endogenous functions. Annu. Rev. Biochem., 50, 207-231. Baenzinger, J.U. and Maynard, Y. (1980) Human hepatic lectin. J. Biol. Chem., 255, 4607-4613. Feizi, T. (1985) Demonstration by monoclonal antibodies that carbohydrate structures of glycoproteins and glycolipids are onto-developmental antigens. Nature, 314, 53-57. Gabius, H.-J., Engelhardt, R., Rehm, S. and Cramer, F. (1984) Biochemical characterization of endogenous carbohydrate-binding proteins from spontaneous murine rhabdomyosarcoma, mammary adenocarcinoma, and ovarian teratoma. J. Natl. Cancer Inst., 73, 1349-1357. Gabius, H.J., Engelhardt, R., Cramer, F., Biitge, R. and Nagel, G.A. (1985) Pattern of endogenous lectins in a human epithelial tumor. Cancer Res., 45, 283-287. Gabius, H.-J., Engelhardt, R., Casper, J., Reile, D., Schumacher, S., Schmoll, H.-J., Gaupner, G. and Cramer, F. (1985) Cell surface lectins of transplantable human teratocarcinoma cells: purification of a new mannan-specific endogenous lectin. Tumour Biol., 6, 145-156. Hakomori, S.-I. (1985) Aberrant glycosylation in cancer cell membranes as focused on glycolipids: overview and perspectives. Cancer Res., 45, 2405-2414. Lehrman, M.A., Haltiwanger, R.S., Eckhardt, A.E. and Hill, R.L. (1984) Carbohydrate-binding protein (lectins) in rat macrophages. In: Progress in Bioorganic Chemistry and Molecular Biology, pp. 141-150. Editor: Y.A. Ovchinikov. Elsevier, Amsterdam. Kawasaki, N., Kawasaki, T. and Yamashina, I. (1983) Isolation and characterization of a mannan-binding protein from human serum. J. Biochem., 94, 937-947. Monsigny, M., Roche, A.-C. and Midoux, P. (1984) Uptake of neoglycoproteins via membrane lectin(s) of L1210 cells evidenced by quantitative flow cytofluorometry and drug targeting. Biol. Cell, 51, 187-196.
145
11 Powell, 12 13
14 15
J.T. (1980) Purification and properties of lung lectins. Biochem. J., 187, 123-129. Sharon, N. and Lis, H. (1982) Glycoproteins: research booming on long-ignored ubiquitous compounds. Mol. Cell. Biochem., 42, 167-187. Simone, J.V., Cassady, J.R. and Filler, R.M. (1982) Cancers of childhood. In: Cancer: principles and Practice of Oncology, pp. 1254-1330. Editors: J.T. DeVita, Jr., S. Hellman and S.A. Rosenberg. J.B. Lippincott Co., Philadelphia. Smets, L.A. and Van Beek, W.P. (1984) Carbohydrates of the tumor cell surface. Biochim. Biophys. Acta, 738, 237-249. Wild, J., Robinson, D. and Winchester, B. (1983) Isolation of mannose-binding proteins from human and rat liver. Biochem. J., 210, 167-174.