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Growth factors and their receptors in human teratocarcinoma
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388
EXPRESSION OF A HIGH MOLECUIAR WEIGHT FORM OF IGFII IN A PLURIPOTENTIAL HUMAN TERATOCARCINOMA CELL LINE
THE EXPRESSION OF A SOLUBLE 14.5 Kdal f l GAIACTOSIDE BINDING LECTIN IS REGULATED DURING MOUSE EHBRYOGENESIS Poirier, F . I , 2, C-T. J. Chan I, P.M. Timmons I, E. R o b e r t s o n 2 and P.W.J. Rigby I. I L a b o r a t o r y o f eukaryotic molecular genetics, National Institute for Medical Research, Mill Hill, London, NW7 IAA, England. ~Department of genetics and development, College of Physicians and Surgeons of Columbia University, 701 West 168th St. New York, NY 10032 USA. Using the technique of in situ hybridization, we have studied the pattern of expression during mouse development of msl-l, a gene encoding a soluble 14.5 Kdal ~-galactoside binding lectin. This analysis has revealed that accumulation of mls-i transcripts is restricted to specific cell types as illustrated by the following examples: I) in 4.5 day old blastocysts, high levels of transcripts are found in the trophectoderm which will exclusively contribute to the formation of extraembryonic tissues, while the cells of the inner cell mass are negative; 2) expression is first detected in the embryo proper at 9.5 days, accumulation of transcripts then being largely limited to the cells of the myotomic part of the somites; 3) the distribution of msl-I transcripts in the central nervous system is highly restricted. In the spinal cord, for example, only the motor neurons are positive. These resuits suggest (a) role(s) for the msl-I lectin in the preimplantation embryo, during somitogenesis and in the developing central nervous system.
Schofield, P.N., W. Engstrom*, M. Tally2 and K. Hall 2. Cancer Research Campaign Developmental Tumours Research Group, Dept. of Zoology, Univ. of Oxford, South Parks Road, Oxford. OXl 3PS.UK ICenter for Biotechnology, Karolinska Institute, H u d d i n g h e Hospital, Sweden. 2Dept. of Endocrinology, Karolinska Institute, Stockholm. We have previously shown that the growth of the human teratocarcinoma cell line Tera-2 in serum free medium can be supported by the sole addition of Insulin like growth factors. Here we report that Tera-2 synthesises at least two different forms of IGFII, one of 15kd, and a second of the expected 7.5kD, as measured by acid gel exclusion chromatography. Both forms are immunologioally cross reactive with antisera to human plasma IGFII and both will stimulate the growth of populations of Tera-2 cells in serum free medium and the division of quiescent human fetal fibroblasts. Radioimmunoassay and r a d i o r e c e p t o r a s s a y indicate that Tera-2 produces about 15ng per 106 cells per 24 hours, which is similar to the rates of IGFII synthesis by several murine Ceratocarcinoma cell lines. Despite their production of IGFII Tera-2 cells do not complete an autocrine loop in serum free medium. We discuss the possibility that this may be due to the cosecretion of a 26kD binding protein by the cells which has immunological identity to a human amniotic fluid IGF binding protein. We have demonstrated that in tissue culture this binding protein inhibits the effect of IGFII on the proliferation of Tera-2 cell populations.
389 Growth Facters and their Receptors in hlmmn Teratocarcinoma. S.M. Weima, M.A. van RooiJen, L. Rijks, A. Feijen, E.J.J. van Zoelen, C.L. Mummery and S.W. de Laat. Hubrecht Laboratory, Uppsalalaan 8, 2584CT Utrecht; Dep. Cell Biology & Genetics, Erasmus University, Dr. Molewaterplein 50, 3015GE Rotterdam. The human teratocarcinomacell line Tera-2 clone 13 (I"2 ci-13) is ~ by retinoic acid (RA) to differentiate in-vitro into endodarmal or neuroectodermal cell types. This system ~ be used as a model to study uhe processes regulating the proliferationand differentia~ tion of the stem cells of human teratocarcinom~ Using specific bio-assays, antibodies and mRNA expression studies we revealed that in T2 ci-13 cells the production of TGF-~ and P[X;F are differentially regulated; i.e. d%e undifferentiatedstate is characterizedby the prockmtion of a high ~ t of PDGF. With respect to growth factor receptors we foLmd that ftr~tional IGF~I and ~ype~B PDGF receptors are expressed by both undifferentiated and RA treated cells. However, the cell surface expression of TGF-fl and ~I~F/TGF-ureceptors appeared to be restricted to undifferentiated stem cells. These studies are currently being extended to tu~or specimen obtained from curative surgery and indicate that polypeptide growth factors are potentially involved in re@~Llatingthe growth and differentiation of human teratecarcinomastem cells.
S120
388
EXPRESSION OF A HIGH MOLECUIAR WEIGHT FORM OF IGFII IN A PLURIPOTENTIAL HUMAN TERATOCARCINOMA CELL LINE
THE EXPRESSION OF A SOLUBLE 14.5 Kdal f l GAIACTOSIDE BINDING LECTIN IS REGULATED DURING MOUSE EHBRYOGENESIS Poirier, F . I , 2, C-T. J. Chan I, P.M. Timmons I, E. R o b e r t s o n 2 and P.W.J. Rigby I. I L a b o r a t o r y o f eukaryotic molecular genetics, National Institute for Medical Research, Mill Hill, London, NW7 IAA, England. ~Department of genetics and development, College of Physicians and Surgeons of Columbia University, 701 West 168th St. New York, NY 10032 USA. Using the technique of in situ hybridization, we have studied the pattern of expression during mouse development of msl-l, a gene encoding a soluble 14.5 Kdal ~-galactoside binding lectin. This analysis has revealed that accumulation of mls-i transcripts is restricted to specific cell types as illustrated by the following examples: I) in 4.5 day old blastocysts, high levels of transcripts are found in the trophectoderm which will exclusively contribute to the formation of extraembryonic tissues, while the cells of the inner cell mass are negative; 2) expression is first detected in the embryo proper at 9.5 days, accumulation of transcripts then being largely limited to the cells of the myotomic part of the somites; 3) the distribution of msl-I transcripts in the central nervous system is highly restricted. In the spinal cord, for example, only the motor neurons are positive. These resuits suggest (a) role(s) for the msl-I lectin in the preimplantation embryo, during somitogenesis and in the developing central nervous system.
Schofield, P.N., W. Engstrom*, M. Tally2 and K. Hall 2. Cancer Research Campaign Developmental Tumours Research Group, Dept. of Zoology, Univ. of Oxford, South Parks Road, Oxford. OXl 3PS.UK ICenter for Biotechnology, Karolinska Institute, H u d d i n g h e Hospital, Sweden. 2Dept. of Endocrinology, Karolinska Institute, Stockholm. We have previously shown that the growth of the human teratocarcinoma cell line Tera-2 in serum free medium can be supported by the sole addition of Insulin like growth factors. Here we report that Tera-2 synthesises at least two different forms of IGFII, one of 15kd, and a second of the expected 7.5kD, as measured by acid gel exclusion chromatography. Both forms are immunologioally cross reactive with antisera to human plasma IGFII and both will stimulate the growth of populations of Tera-2 cells in serum free medium and the division of quiescent human fetal fibroblasts. Radioimmunoassay and r a d i o r e c e p t o r a s s a y indicate that Tera-2 produces about 15ng per 106 cells per 24 hours, which is similar to the rates of IGFII synthesis by several murine Ceratocarcinoma cell lines. Despite their production of IGFII Tera-2 cells do not complete an autocrine loop in serum free medium. We discuss the possibility that this may be due to the cosecretion of a 26kD binding protein by the cells which has immunological identity to a human amniotic fluid IGF binding protein. We have demonstrated that in tissue culture this binding protein inhibits the effect of IGFII on the proliferation of Tera-2 cell populations.
389 Growth Facters and their Receptors in hlmmn Teratocarcinoma. S.M. Weima, M.A. van RooiJen, L. Rijks, A. Feijen, E.J.J. van Zoelen, C.L. Mummery and S.W. de Laat. Hubrecht Laboratory, Uppsalalaan 8, 2584CT Utrecht; Dep. Cell Biology & Genetics, Erasmus University, Dr. Molewaterplein 50, 3015GE Rotterdam. The human teratocarcinomacell line Tera-2 clone 13 (I"2 ci-13) is ~ by retinoic acid (RA) to differentiate in-vitro into endodarmal or neuroectodermal cell types. This system ~ be used as a model to study uhe processes regulating the proliferationand differentia~ tion of the stem cells of human teratocarcinom~ Using specific bio-assays, antibodies and mRNA expression studies we revealed that in T2 ci-13 cells the production of TGF-~ and P[X;F are differentially regulated; i.e. d%e undifferentiatedstate is characterizedby the prockmtion of a high ~ t of PDGF. With respect to growth factor receptors we foLmd that ftr~tional IGF~I and ~ype~B PDGF receptors are expressed by both undifferentiated and RA treated cells. However, the cell surface expression of TGF-fl and ~I~F/TGF-ureceptors appeared to be restricted to undifferentiated stem cells. These studies are currently being extended to tu~or specimen obtained from curative surgery and indicate that polypeptide growth factors are potentially involved in re@~Llatingthe growth and differentiation of human teratecarcinomastem cells.
S120