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Surface-associated proteolysis — A common feature of cells possessing high lectin-agglutinability
Medical Hypotheses 8: 423-425, 1982
SURFACE-ASSOCIATED PROTEOLYSIS - A COMMON FEATURtiOF CELL& POSSESSING HIGH LECTIN-AGGLUTINABILITY Narendra G. Mehta. Biological Chemistry Division, Cancer Research Institute, Parel, Bombay 400 012, India A well-established difference between normal and transformed cells pertains to their agglutinability with plant lectins: While normal cells require high concentrations of the lectin for agglutination, transformed cells agglutinate at relatively low concentrations (1). If, however, normal cells are pre-treated with proteolytic enzymes, they acquire high lectin agglutinability similar to transformed cells (2,3). Also, some normal cell types exist which agglutinate at low lectin concentrations without prior proteolysis. In this note we wish to point out that all these cell types, like tumor cells, are secretors of proteolytic enzymes (Table 1). Table 1. Cell types showing high lectin-agglutinability and surface proteolysis Cell type References Agglutinability Mitotic cells Lymphocytes Sperms Preimplantation embryos Mobile and invasive embryonic cells Cells treated with high concentrations of vitamin A or anti-cellular serum, or infected with non-oncogenic viruses DMSO-induced erythroleukemia cells Tumor/transformed cells
Surface proteolysis 5
k see, 10
11,12
13914
15
16917
18
19,20
19,20
see,
21 1
7-9
see, 2";
It is clear that all cell types, normal and transformed, ing high lectin-agglutinability have the feature of surfa~~'~~~~eolysis common to them. Two observations underscore tnis corre-
423
lation: (a) Unfertilized eggs are not agglutinated by lectins, but pre-implantation embryos are (13,14); pre-implantetion is precisely the stage at which embryos start to secrete proteases (15). (b) Friend erythro1eukemia cells do not possess high concanavelin A-agglutinability, but at a certain stage after induction with dimethylsulfoxide, the cells become highly agglutinable with the lectin, and simultaneously exhibit surface proteolysis. The above correlation between secretion of proteases and high lectinagglutinability, the fact that normal cells acquire enhanced agglutinability following in vitro proteolysis, and the reports (see, 22) that incubation of transformed cells with proteolytic inhibitors reduces their egglutinabilitg, make a compelling case for surface proteolysis as the prime cause of lectin agglutinability of cells. These observations also lead to the suggestion that the state of transformation per se is not the determinant of cell agglutinability, but the proteolysis associated with it is the sole reason, as it is with mitotic cells, embryonic cells, etc. Whether the protease action on the cell surface leads to enhanced agglutinability by disruption of the cytoskeleton (23,24) or by another mechanism remains to be determined. It may be mentioned, however, that trypsin-treatment of cells is reported not to alter the mobility of the ligand-receptor complex (25). RdFERENCES 1. Nicolson GL. Transmembrane control of the receptors on normal and tumor cells. II. Surface changes associated with transformation and malignancy. Biochim Biophys Acta 458: l-72, 1976. 2. Burger MM, A difference in the architecture of the surface membrane of normal and virally transformed cells. Proc Nat1 Acad Sci USA 62: 994-1001, 1969. 3. Inbar M, Sechs L. Interaction of the carbohydrate-binding concanavalin A with normal and transformed cells. Proc Nat1 Acad Sci USA 63: 141.8-1425, 1969. 4. Collard JG, Temmink JHM, Smets LA. Cell cycle dependent agglutinebility, distribution of concanavalin A binding sites and surface morphology of normal and transformed fibroblasts. pp 221-244 in Concanavalin A (TK Chowdhury, AK Weiss, eds) Plenum, New York, 1975. 5. Bosmsnn HB. Release of specific protease during mitotic cycle of L 5178~ murine leukemic cells by sublethal autolysis, Nature 249: 144-145, 1974. 6. Loor F. Lectin-induced lymphocyte agglutination. An active cellular process? tip Cell Res 82: 415-425, 1973. 7. Grayzel AI, Hatcher VB, Lazarus GS. Protease activity of normal and PHA stimulated human lymphocytes. Cell Immunol 18: 210-219, 1975. 8. Hart DA, Streilin JS. Effect of protease inhibitors on mitogen stimulation of hamster lymphoid cells. Exp Cell Res 102: 253-263, 1976.
424
9.
10.
11.
12. 13.
14. 15. 16.
17.
16. 199 20. 21. 22,
Saito M, Aoyagi T, Umezawa H, Nagai Y. Bestatin, a new specific inhibitor of amino peptidases, enhances activation of smell lymphocytes by concanavalin A. Biochem Biophys des Commun 76: 526-533, 1977. Oppenheimer SB. Interaction of lectins with embryonic cell surfaces. Curr Topics Devel Biol 11: l-16, 1977. 3tambaugh R, Buckley J. Zona pellucida dissolution enzymes Gcience 161: 585-586, 1966. of the rabbit sperm head. Fed Proc Gould KG. Application of in vitro fertilization. 32: 2069-2074, 1973. Pienkowski M. Study of growth reguletion of preimplantation mouse embryos using concanavalin A. Proc Sot dxp Biol Med 145: 464-469, 1974. Magnuson T, Stackpole CW. Lectin-mediated agglutination of dxp Cell Hes 116: 466-469, preimplantation mouse embryos. 1978. Denker HW. Blastocyst protease and implantation: I?;ffectof overiectomy and progesterone substitution in the rabbit. Acts Endocrinol 70: 592-602, 1972. Zalik 3E, Cook GMW. Comparison of early embryonic and diffeInteraction of lectins with rentiating cell surfaces. Biochim Biophys Acta 419-z plasma membrane components. 119-136, 1976. Fraser BR, Zalik Sz, Lectin-mediated agglutination of amphibien embryonic cells. J Cell Sci 27: 227-243, 1977. Strickland 9, Reich E, Sherman MI. Plasminogen activator in early e&mbryogenesis: enzyme production by trophoblast and parietal endoderm. Cell 9: 231-240, 1976. Poste G. Changes in susceptibility of normal cells to agglutination by plant lectins following modification of the cell coat material, tip Cell Res 73: 319-328, 1972. Poste G. Interaction of concanavalin A witn the surfece of virus-infected cells. pp 117-152 in Concanavalin A (TK Chowdhury, AK Weiss, eds) Plenum, New York, 1975. Eisen H, Nasi S, Georgopoulos CP, Arndt-Jovin D, Ostertag W. Surface changes in differentiating Friend erythroleukemic cells in culture. Cell 10: 689-695, 1977. Roblin R, Chou IN, Black PH. Proteolytic enzymes, cell surface Adv Csncer Hes 22: 203changes, and viral transformation.
260, 1975. 23.
24.
25.
Pollack R, Rifkin, D. Actin-containing cables within ancnoragedependent rat embryo cells are dissociated by plasmin and trypsin. Cell 6: 495-506, 1975. Furcht LT, Wendlschafer-Crabb G. Trypsin-induced coordinate alterations in cell shape, cgtoskeleton, and intrinsic membrene structure of contact-inhibited cells. dxp Cell Res 114: l-14, 1978. Edidin M, Wei T. Diffusion rates of cell surface antigens I. Analysis of the population. of mouse-human heterokaryons. J Cell Biol 75: 475-482, 1977.
425
SURFACE-ASSOCIATED PROTEOLYSIS - A COMMON FEATURtiOF CELL& POSSESSING HIGH LECTIN-AGGLUTINABILITY Narendra G. Mehta. Biological Chemistry Division, Cancer Research Institute, Parel, Bombay 400 012, India A well-established difference between normal and transformed cells pertains to their agglutinability with plant lectins: While normal cells require high concentrations of the lectin for agglutination, transformed cells agglutinate at relatively low concentrations (1). If, however, normal cells are pre-treated with proteolytic enzymes, they acquire high lectin agglutinability similar to transformed cells (2,3). Also, some normal cell types exist which agglutinate at low lectin concentrations without prior proteolysis. In this note we wish to point out that all these cell types, like tumor cells, are secretors of proteolytic enzymes (Table 1). Table 1. Cell types showing high lectin-agglutinability and surface proteolysis Cell type References Agglutinability Mitotic cells Lymphocytes Sperms Preimplantation embryos Mobile and invasive embryonic cells Cells treated with high concentrations of vitamin A or anti-cellular serum, or infected with non-oncogenic viruses DMSO-induced erythroleukemia cells Tumor/transformed cells
Surface proteolysis 5
k see, 10
11,12
13914
15
16917
18
19,20
19,20
see,
21 1
7-9
see, 2";
It is clear that all cell types, normal and transformed, ing high lectin-agglutinability have the feature of surfa~~'~~~~eolysis common to them. Two observations underscore tnis corre-
423
lation: (a) Unfertilized eggs are not agglutinated by lectins, but pre-implantation embryos are (13,14); pre-implantetion is precisely the stage at which embryos start to secrete proteases (15). (b) Friend erythro1eukemia cells do not possess high concanavelin A-agglutinability, but at a certain stage after induction with dimethylsulfoxide, the cells become highly agglutinable with the lectin, and simultaneously exhibit surface proteolysis. The above correlation between secretion of proteases and high lectinagglutinability, the fact that normal cells acquire enhanced agglutinability following in vitro proteolysis, and the reports (see, 22) that incubation of transformed cells with proteolytic inhibitors reduces their egglutinabilitg, make a compelling case for surface proteolysis as the prime cause of lectin agglutinability of cells. These observations also lead to the suggestion that the state of transformation per se is not the determinant of cell agglutinability, but the proteolysis associated with it is the sole reason, as it is with mitotic cells, embryonic cells, etc. Whether the protease action on the cell surface leads to enhanced agglutinability by disruption of the cytoskeleton (23,24) or by another mechanism remains to be determined. It may be mentioned, however, that trypsin-treatment of cells is reported not to alter the mobility of the ligand-receptor complex (25). RdFERENCES 1. Nicolson GL. Transmembrane control of the receptors on normal and tumor cells. II. Surface changes associated with transformation and malignancy. Biochim Biophys Acta 458: l-72, 1976. 2. Burger MM, A difference in the architecture of the surface membrane of normal and virally transformed cells. Proc Nat1 Acad Sci USA 62: 994-1001, 1969. 3. Inbar M, Sechs L. Interaction of the carbohydrate-binding concanavalin A with normal and transformed cells. Proc Nat1 Acad Sci USA 63: 141.8-1425, 1969. 4. Collard JG, Temmink JHM, Smets LA. Cell cycle dependent agglutinebility, distribution of concanavalin A binding sites and surface morphology of normal and transformed fibroblasts. pp 221-244 in Concanavalin A (TK Chowdhury, AK Weiss, eds) Plenum, New York, 1975. 5. Bosmsnn HB. Release of specific protease during mitotic cycle of L 5178~ murine leukemic cells by sublethal autolysis, Nature 249: 144-145, 1974. 6. Loor F. Lectin-induced lymphocyte agglutination. An active cellular process? tip Cell Res 82: 415-425, 1973. 7. Grayzel AI, Hatcher VB, Lazarus GS. Protease activity of normal and PHA stimulated human lymphocytes. Cell Immunol 18: 210-219, 1975. 8. Hart DA, Streilin JS. Effect of protease inhibitors on mitogen stimulation of hamster lymphoid cells. Exp Cell Res 102: 253-263, 1976.
424
9.
10.
11.
12. 13.
14. 15. 16.
17.
16. 199 20. 21. 22,
Saito M, Aoyagi T, Umezawa H, Nagai Y. Bestatin, a new specific inhibitor of amino peptidases, enhances activation of smell lymphocytes by concanavalin A. Biochem Biophys des Commun 76: 526-533, 1977. Oppenheimer SB. Interaction of lectins with embryonic cell surfaces. Curr Topics Devel Biol 11: l-16, 1977. 3tambaugh R, Buckley J. Zona pellucida dissolution enzymes Gcience 161: 585-586, 1966. of the rabbit sperm head. Fed Proc Gould KG. Application of in vitro fertilization. 32: 2069-2074, 1973. Pienkowski M. Study of growth reguletion of preimplantation mouse embryos using concanavalin A. Proc Sot dxp Biol Med 145: 464-469, 1974. Magnuson T, Stackpole CW. Lectin-mediated agglutination of dxp Cell Hes 116: 466-469, preimplantation mouse embryos. 1978. Denker HW. Blastocyst protease and implantation: I?;ffectof overiectomy and progesterone substitution in the rabbit. Acts Endocrinol 70: 592-602, 1972. Zalik 3E, Cook GMW. Comparison of early embryonic and diffeInteraction of lectins with rentiating cell surfaces. Biochim Biophys Acta 419-z plasma membrane components. 119-136, 1976. Fraser BR, Zalik Sz, Lectin-mediated agglutination of amphibien embryonic cells. J Cell Sci 27: 227-243, 1977. Strickland 9, Reich E, Sherman MI. Plasminogen activator in early e&mbryogenesis: enzyme production by trophoblast and parietal endoderm. Cell 9: 231-240, 1976. Poste G. Changes in susceptibility of normal cells to agglutination by plant lectins following modification of the cell coat material, tip Cell Res 73: 319-328, 1972. Poste G. Interaction of concanavalin A witn the surfece of virus-infected cells. pp 117-152 in Concanavalin A (TK Chowdhury, AK Weiss, eds) Plenum, New York, 1975. Eisen H, Nasi S, Georgopoulos CP, Arndt-Jovin D, Ostertag W. Surface changes in differentiating Friend erythroleukemic cells in culture. Cell 10: 689-695, 1977. Roblin R, Chou IN, Black PH. Proteolytic enzymes, cell surface Adv Csncer Hes 22: 203changes, and viral transformation.
260, 1975. 23.
24.
25.
Pollack R, Rifkin, D. Actin-containing cables within ancnoragedependent rat embryo cells are dissociated by plasmin and trypsin. Cell 6: 495-506, 1975. Furcht LT, Wendlschafer-Crabb G. Trypsin-induced coordinate alterations in cell shape, cgtoskeleton, and intrinsic membrene structure of contact-inhibited cells. dxp Cell Res 114: l-14, 1978. Edidin M, Wei T. Diffusion rates of cell surface antigens I. Analysis of the population. of mouse-human heterokaryons. J Cell Biol 75: 475-482, 1977.
425