213
Ann. Hum. Genet. (1991), 55, 213-216 Printed in Great Britain
Assignment of the Hepatocyte Growth Factor (HGF) to chromosome 7q22-qter B. LAGUDA," C. SELDEN,? M. JONES,? H. HODGSONf AND N. K. SPURR* * H u m a n Genetic Resources Lab., Imperial Cancer Research Fund, Clare Hall Laboratories, Blanche Lane, South Mimms, Herts. EN6 3LD t Royal Postgraduate Medical School, Hammersmith Hospital, D u Cane Road, London W12 OM\r SUMMARY
The hepatocyte growth factor (HGF)is thought to be important in the growth of hepatocytes during normal foetal liver growth and following liver damage. The human gene encoding HGF has been mapped to chromosome 7 and shown to be localized in the region q22-qter.
INTRODUCTION
Hepatocyte growth factor (HGF) was originally described in serum of rats after a partial hepatectomy (Nakamura et al. 1984) and in human serum following major hepatic resection of hepatocellular cancer (Selden et al. 1986). Recently, it has been purified from plasma of patients with fulminant hepatic failure (Gohda et al. 1988), normal rabbit serum (Zarnegar et al. 1989) and human platelets (Nakamura et al. 1989). Originally thought to be specific for hepatocytes, it is now clear that it acts on many cell types, excluding those of fibroblast origin (Kan et al. 1991). It has also since been shown to belong to a family of fibroblast growth factors with very similar structure and function (Rubin et al. 1991). Kinoshita et al. (1989) have shown HGF to be produced by the non-parenchymal cells of the liver. Recently, HGF and scatter factor have been shown to be highly similar in structure and may be identical (Gherardi & Stoker, 1990). Scatter factor has been shown to stimulate the dissociation and scattering of epithelial cells. Other human growth factors specific for fibroblasts and epithelial cell types have been cloned and mapped in humans and the assignment of the hepatocyte growth factor would yield information on the possible links between these growth factors. Therefore, using somatic cell hybrids, and a DNA probe specific for HGF, we have assigned the gene to chromosome 7 .
MATERIALS AND METHODS
Somatic cell hybrids All the hybrids used in this work have been described previously and are referenced in the text and Table 1 as appropriate. Genomic DNA was prepared using an Applied Biosystems DNA extractor model 340A using supplied reagents.
Southern blot and DNA hybridization DNA was digested with restriction enzymes using standard conditions (Sambrook et al. 1989) and transferred to Hybond N using condit.ions supplied by the manufacturer (Amersham
214
B.LAGUDAAND 1
2
3
OTHERS
4
5
6
7
-13.5 -13-0
Fig. 1. Southern blot of genomic DNA samples digested with EcoRI and hybridized with the radiolabelled HGF probe. This autoradiograph shows human (track 2), mouse (track 1) and five somatic cell hybrids: FIR5 (track 3), HorlSX (track 4),clone 21E (track 5 ) , FIR5R3 (track 6) and PCTBl .8 (track 7). The hybrid clone 21E clearly shows the positive human signal, all the remaining hybrids were negative.
International). The hepatocyte growth factor probe was radiolabelled with 32PadCTP using random oligonucleotide priming (Feinberg & Vogelstein, 1983) and hybridization was carried out using standard methods. The filters were washed to a final salt concentration of 0 2 x SSC, 0.1 YOSDS a t 65 "C.
Hepatocyte Growth Factor probe (HGF) The cloning of the human probe for HGF has been described previously (Selden et al. 1990). An EcoRIIPst 569 bp fragment was isolated from the bluescribe vector for use as a hybridization probe.
RESULTS
Gene Assignment Southern blots of EcoRI-digested somatic cell hybrid and control DNAs were probed with the 569 base pair HGF-specific probe which detects a major fragment in human DNA a t 13.5 kb (Fig. 1, track 2). I n mouse DNA, the probe detects a strongly hybridizing band a t 13.0 kb (Fig. 1, track 1). Results from the analysis are summarized in Table 1. Figure 1 illustrates the screening of a selection of hybrids, including the hybrid clone 21E which contains chromosome 7 as its only human contribution (Croce & Koprowski, 1974). This hybrid showed a positive signal to the human fragment (Fig. 1,track 5).This was the only chromosome to show complete concordance (Table 1). The HGF gene was further localized with the hybrid FIR5 (Hobart et al. 1981) which contains an X/7 translocation (Fig. 1, track 3) (Xqter-ql3:7pter-q22). FIR5 was negative for human sequences and this localized the HGF gene to the region q22-qter on chromosome 7.
215
Assignment of HGF to chromosome 7q22-qter Table 1 . Hybridization of human-rodent somatic cell hybrids with the HGF probe
Assignment of Hepatic Growth Factor Hybrid I z 3 4 5 6 7 8 9 10 1 1 I Z 1 3 14 1 5 16 17 18 1 9 zo 21 zz X HGFRef. Name I CTP34B4 5 MOG34A4 + - - - I - + - - - + + - - - - CTP41A2 + 2 LSR8 - - + t - + t + + 3 + + + + - - + - - SIR74ii - - - - _ - - - - - - - - + 4 CLONE21E _ _ _ _ _ _ + - - 6 HORP9 . 5 - - - - - - - - - + + + - + - - - - - - - + - - + - - + - + - - - 7 FGlO - - + _ _ - - - _ + + - - 8 DT1.2.4 _ - - - - * - - - - _ + - - - + - - - - * - 9 FIR5 HORL9X FIR5R3 PCTBAl . 8 *, hybrid containing a translocation. t, trace. References: 1, Jones et aZ. 1976; 2, Spurr et al. 1986; 3, Whitehead et al. 1982; 4, Croce & Koprowski 1974; 5, Solomon et al. 1979; 6, van Heyningen et al. 1975; 7, Kielty et al. 1982; 8, Swallow et al. 1977; 9, Hobart et al. 1981; 10, Heisterkamp et al. 1982; 11, Bai et al. 1982.
+++-++++--
+-++++++-+ -+++++++-+
+ + + + + + + +
+ - + + + - - - + + ++ -+ -+ + + + +- ++ ++ + + + + + + + + + + + + + - - + - - + - + + - + + - + + + + -
DISCUSSION
The hepatic growth factor (HGF) is assigned to chromosome 7 and localized to 7q22-qter. A number of growth factors and receptors have been previously assigned to chromosome 7. These include epidermal growth factor receptor a t 7p13-pl2, insulin-like growth factor binding protein a t 7p13-q22, growth control factor 1 at 7q, neutrophil migration factor a t 7q22, T-cell tumour invasion and mutation factor a t 7q (HGMlO, 1989). Very recently, the receptor for HGF has been ascribed to the protein product of the c-met protooncogene, a tyrosine kinase of 195kDa, comprised of an a 50kDa and /3 145kDa subunit (Bottaro et al. 1991). The c-met gene is localized on chromosome 7q22-7q31. It is of particular interest that the HGF ligand and its receptor are located on chromosome 7, and that alterations in this region of the chromosome have been associated with some gastrointestinal tumours. The fibroblast and epidermal growth factors have been assigned to other chromosomes : FGFA a t 5q31.3-33.2, FGFB a t 4q25 and EGF a t 4q25 (HGM10, 1989). Thus the growth factors are clearly a dispersed group of genes showing different cell specificities. The authors would like to thank Andrea Kessler for excellent secretarial assistance and Catriona MacGeoch for advice during this work. Work on HGF was kindly supported by the Cancer Research Campaign. REFERENCES
BAI, Y., SHEER,D., HIORNS,L., KNOWLES,R. W. & TUNNACLIFFE, A. (1982). A monoclonal antibody recognizing a cell surface antigen coded for by a gene on human chromosome 17. Ann. Hum. Genet. 46, 337-347. BOTTARO, D., RUBIN,J., FALETTO, D., CHAN,A., KMIECIK,T., VANDEWOUDE,G. & AARONSON, S. (1991). Identification of the hepatocyte growth factor receptor as the c-met protooncogene product. Science 251, 802-804. CROCE,C. M. & KOPROWSKI, H. (1974). Somatic cell hybrids between mouse peritoneal macrophages and SV40 transformed human cells. 1. Positive control of the transformed phenotype by the human chromosome 7 carrying the SV-40 genome. J. Exp. M e d . 140, 1221-1229. 10
H G E 55
216
B.LAGUDAAND
OTHERS
A. p . 8~ VOGELSTEIN, B. (1983). A technique for radiolabelling DNA restriction endonuclease fragments to high specific activity. Anal. Biochem. 132, 6-13. GHERARDI, E. 8~ STOKER,M. (1990). Hepatocytes and scatter factor. Nature 346, 228. GOHDA,E., TSUBOUCHI, H., NAKAYAMA, H., HIRONO,S., SAKIYAMA, O., TAKAHASHI, K., MIYAZAKI, H., S. & DAIKUHARA, Y. (1988). Purification and partial characterization of hepatocyte growth HASHIMOTO, factor from plasma of a patient with fulminant hepatic failure. J. Clin. Invest. 81, 414-419. HEISTERKAMP, N., GROFFEN,J . , STEPHENSON, J . R . , SPURR,N.K., GOODFELLOW, P . N . , SOLOMON, E., CARRITT, B. & BODMER, W. F. (1982). Chromosomal localization of human cellular homologues of two viral oncogenes. Nature 299, 747-749. HOBART, M. J . , RABBITTS,T. H., GOODFELLOW, P. N., SOLOMON, E., CHAMBERS, S., SPURR,N. & POVEY, S. (1981). Immunoglobulin heavy chain genes in humans are located on chromosome 14. Ann. Hum. Genet. 45, 33 1-335. HUMAN GENEMAPPING 10 . (1989). Tenth International Workshop on Human Gene Mapping. Cytogenet. Cell Genet. 51, Nos. 1 4 . Karger Publishers Inc. JONES, E. A., GOODFELLOW, P. N., KENNETT, R. H. & BODMER, W. F. (1976). The independent expression of HLA and b2 microglobulin on human-mouse hybrids. S o m t . Cell Genet. 2, 483496. KAN,M., ZHANG, G., ZARNEGAR, R., MICHALOPOULOS,G., MYOKEN,Y., MCKEEHAN, W. & STEVENS, J . (1991). Hepatocyte growth factor/hepatopoietin A stimulates the growth of rat kidney proximal tubule epithelial cells (RPTE), rat nonparenchymal liver cells, human melanoma cells, mouse keratinocytes and stimulates anchorage-independent growth of SV-40 transformed RPTE. Biochem. Biophys. Res. Commun. 174,331-337. KIELTY,C. M., POVEY, S. & HOPKINSON, D. A. (1982). Regulation of expression of liver-specific enzymes. 111. Further analysis of a series of rat hepatoma x human somatic cell hybrids. Ann. Hum. Genet. 46, 307-327. KINOSHITA, T., TASHIRO,K. & NAKAMURA, T. (1989). Marked increase of HGF mRNA in non-parenchymal liver cells of rats treated with hepatotoxins. Biochem. Biophys. Res. Commun. 165, 1229-1234. NAKAMURA, T., NAWA,K. & ICHIHARA, A. (1984). Partial purification and characterization of hepatocyte growth factor from serum of hepatectomized rats. Biochem. Biophys. Res. Commun. 122, 1450-1459. NAKAMURA, T., NISHIZAWA, T., HAGIYA,M., SEKI,T., SHIMONISHI, M., SUGIMURA, A., TASHIRO, K. & SHIMIZU, S. (1989). Molecular cloning and expression of human hepatocyte growth factor. Nature 342, 440443. RUBIN,J. S., CHAN,A. M-L., BOTTARO, D. P., BURGESS, W. H., TAYLOR, W. G., CECH, A. C., HIRSCHFIELD, D. P. W. & AARONSON, S. A. (1991). A broad-spectrum human lung fibroblastW., WONG,J., MIKI, T., FINCH, derived mitogen is a variant of hepatocyte growth factor. Proc. Natl. Acad. Sci. USA 88, 415-419. SAMBROOK, J., FRITSCH, E. F. & MANIATIS,T. (1989). Molecular Cloning: A Laboratory Manual, 2nd edn. New York : Cold Spring Harbor Press. H. (1986). Human serum does contain a high SELDEN, C., JOHNSTONE, R., DARBY,H., GUPTA,S. & HODGSON, molecular weight hepatocyte growth factor : studies pre- and post-hepatic resection. Biochem. Biophys. Res. Commun. 139, 361-366. SELDEN,C., JONES, M., WADE,D. & HODGSON, H. (1990). Hepatotropin mRNA expression in human foetal liver development and in liver regeneration. FEBS Lett. 270, 81-84. SOLOMON, E., SWALLOW, D., BURGESS, S. & EVANS,L. (1979). Assignment of the human acid a-glucosidase gene (aGLU) to chromosome 17 using somatic cell hybrids. Ann. Hum. Genet. 42, 275-281. SPURR,N. K., DURBIN,H., SHEER,D., PARKAR, M., BOBROW, L. & BODMER, W. F. (1986). Characterization and chromosomal assignment of a human cell surface antigen defined by the monoclonal antibody AUAI. Int. J. Cancer 38, 631-636. SWALLOW,D.M., SOLOMON, E. & PAJUNEN, L. (1977). Immunochemical analysis of the N-acetyl hexosaminidases in human-mouse hybrids made using a double selective system. Cytogenet. Cell Genet. 18, 136-148. VAN HEYNINQEN, V., BOBROW, M., BODMER, W. F., GARDINER, S. E., POVEY, S. & HOPKINSON, D. A. (1975). Chromosome assignment of some human enzyme loci : mitochondria1 malate dehydrogenase to 7, mannose phosphate isomerase and pyruvate kinase to 15 and probably, esterase D to 13. Ann. Hum. Genet. 38, 295-303. WHITEHEAD, A. S., SOLOMON, E., CHAMBERS, S., BODMER, W. F., POVEY, S. & FEY,G. (1982). Assignment of the structural gene for the third component of human complement to chromosome 19. Proc. Natl. Acad. Sci. USA 79, 5012-5025. ZARNEOAR, R. & MICHALOPOULOS,G. ( 1989). Purification and biological characterization of human hepatopoietin A, a polypeptide growth factor for hepatocytes. Cancer Res. 49, 3314-3320. FEINBERQ,
Ann. Hum. Genet. (1991), 55, 213-216 Printed in Great Britain
Assignment of the Hepatocyte Growth Factor (HGF) to chromosome 7q22-qter B. LAGUDA," C. SELDEN,? M. JONES,? H. HODGSONf AND N. K. SPURR* * H u m a n Genetic Resources Lab., Imperial Cancer Research Fund, Clare Hall Laboratories, Blanche Lane, South Mimms, Herts. EN6 3LD t Royal Postgraduate Medical School, Hammersmith Hospital, D u Cane Road, London W12 OM\r SUMMARY
The hepatocyte growth factor (HGF)is thought to be important in the growth of hepatocytes during normal foetal liver growth and following liver damage. The human gene encoding HGF has been mapped to chromosome 7 and shown to be localized in the region q22-qter.
INTRODUCTION
Hepatocyte growth factor (HGF) was originally described in serum of rats after a partial hepatectomy (Nakamura et al. 1984) and in human serum following major hepatic resection of hepatocellular cancer (Selden et al. 1986). Recently, it has been purified from plasma of patients with fulminant hepatic failure (Gohda et al. 1988), normal rabbit serum (Zarnegar et al. 1989) and human platelets (Nakamura et al. 1989). Originally thought to be specific for hepatocytes, it is now clear that it acts on many cell types, excluding those of fibroblast origin (Kan et al. 1991). It has also since been shown to belong to a family of fibroblast growth factors with very similar structure and function (Rubin et al. 1991). Kinoshita et al. (1989) have shown HGF to be produced by the non-parenchymal cells of the liver. Recently, HGF and scatter factor have been shown to be highly similar in structure and may be identical (Gherardi & Stoker, 1990). Scatter factor has been shown to stimulate the dissociation and scattering of epithelial cells. Other human growth factors specific for fibroblasts and epithelial cell types have been cloned and mapped in humans and the assignment of the hepatocyte growth factor would yield information on the possible links between these growth factors. Therefore, using somatic cell hybrids, and a DNA probe specific for HGF, we have assigned the gene to chromosome 7 .
MATERIALS AND METHODS
Somatic cell hybrids All the hybrids used in this work have been described previously and are referenced in the text and Table 1 as appropriate. Genomic DNA was prepared using an Applied Biosystems DNA extractor model 340A using supplied reagents.
Southern blot and DNA hybridization DNA was digested with restriction enzymes using standard conditions (Sambrook et al. 1989) and transferred to Hybond N using condit.ions supplied by the manufacturer (Amersham
214
B.LAGUDAAND 1
2
3
OTHERS
4
5
6
7
-13.5 -13-0
Fig. 1. Southern blot of genomic DNA samples digested with EcoRI and hybridized with the radiolabelled HGF probe. This autoradiograph shows human (track 2), mouse (track 1) and five somatic cell hybrids: FIR5 (track 3), HorlSX (track 4),clone 21E (track 5 ) , FIR5R3 (track 6) and PCTBl .8 (track 7). The hybrid clone 21E clearly shows the positive human signal, all the remaining hybrids were negative.
International). The hepatocyte growth factor probe was radiolabelled with 32PadCTP using random oligonucleotide priming (Feinberg & Vogelstein, 1983) and hybridization was carried out using standard methods. The filters were washed to a final salt concentration of 0 2 x SSC, 0.1 YOSDS a t 65 "C.
Hepatocyte Growth Factor probe (HGF) The cloning of the human probe for HGF has been described previously (Selden et al. 1990). An EcoRIIPst 569 bp fragment was isolated from the bluescribe vector for use as a hybridization probe.
RESULTS
Gene Assignment Southern blots of EcoRI-digested somatic cell hybrid and control DNAs were probed with the 569 base pair HGF-specific probe which detects a major fragment in human DNA a t 13.5 kb (Fig. 1, track 2). I n mouse DNA, the probe detects a strongly hybridizing band a t 13.0 kb (Fig. 1, track 1). Results from the analysis are summarized in Table 1. Figure 1 illustrates the screening of a selection of hybrids, including the hybrid clone 21E which contains chromosome 7 as its only human contribution (Croce & Koprowski, 1974). This hybrid showed a positive signal to the human fragment (Fig. 1,track 5).This was the only chromosome to show complete concordance (Table 1). The HGF gene was further localized with the hybrid FIR5 (Hobart et al. 1981) which contains an X/7 translocation (Fig. 1, track 3) (Xqter-ql3:7pter-q22). FIR5 was negative for human sequences and this localized the HGF gene to the region q22-qter on chromosome 7.
215
Assignment of HGF to chromosome 7q22-qter Table 1 . Hybridization of human-rodent somatic cell hybrids with the HGF probe
Assignment of Hepatic Growth Factor Hybrid I z 3 4 5 6 7 8 9 10 1 1 I Z 1 3 14 1 5 16 17 18 1 9 zo 21 zz X HGFRef. Name I CTP34B4 5 MOG34A4 + - - - I - + - - - + + - - - - CTP41A2 + 2 LSR8 - - + t - + t + + 3 + + + + - - + - - SIR74ii - - - - _ - - - - - - - - + 4 CLONE21E _ _ _ _ _ _ + - - 6 HORP9 . 5 - - - - - - - - - + + + - + - - - - - - - + - - + - - + - + - - - 7 FGlO - - + _ _ - - - _ + + - - 8 DT1.2.4 _ - - - - * - - - - _ + - - - + - - - - * - 9 FIR5 HORL9X FIR5R3 PCTBAl . 8 *, hybrid containing a translocation. t, trace. References: 1, Jones et aZ. 1976; 2, Spurr et al. 1986; 3, Whitehead et al. 1982; 4, Croce & Koprowski 1974; 5, Solomon et al. 1979; 6, van Heyningen et al. 1975; 7, Kielty et al. 1982; 8, Swallow et al. 1977; 9, Hobart et al. 1981; 10, Heisterkamp et al. 1982; 11, Bai et al. 1982.
+++-++++--
+-++++++-+ -+++++++-+
+ + + + + + + +
+ - + + + - - - + + ++ -+ -+ + + + +- ++ ++ + + + + + + + + + + + + + - - + - - + - + + - + + - + + + + -
DISCUSSION
The hepatic growth factor (HGF) is assigned to chromosome 7 and localized to 7q22-qter. A number of growth factors and receptors have been previously assigned to chromosome 7. These include epidermal growth factor receptor a t 7p13-pl2, insulin-like growth factor binding protein a t 7p13-q22, growth control factor 1 at 7q, neutrophil migration factor a t 7q22, T-cell tumour invasion and mutation factor a t 7q (HGMlO, 1989). Very recently, the receptor for HGF has been ascribed to the protein product of the c-met protooncogene, a tyrosine kinase of 195kDa, comprised of an a 50kDa and /3 145kDa subunit (Bottaro et al. 1991). The c-met gene is localized on chromosome 7q22-7q31. It is of particular interest that the HGF ligand and its receptor are located on chromosome 7, and that alterations in this region of the chromosome have been associated with some gastrointestinal tumours. The fibroblast and epidermal growth factors have been assigned to other chromosomes : FGFA a t 5q31.3-33.2, FGFB a t 4q25 and EGF a t 4q25 (HGM10, 1989). Thus the growth factors are clearly a dispersed group of genes showing different cell specificities. The authors would like to thank Andrea Kessler for excellent secretarial assistance and Catriona MacGeoch for advice during this work. Work on HGF was kindly supported by the Cancer Research Campaign. REFERENCES
BAI, Y., SHEER,D., HIORNS,L., KNOWLES,R. W. & TUNNACLIFFE, A. (1982). A monoclonal antibody recognizing a cell surface antigen coded for by a gene on human chromosome 17. Ann. Hum. Genet. 46, 337-347. BOTTARO, D., RUBIN,J., FALETTO, D., CHAN,A., KMIECIK,T., VANDEWOUDE,G. & AARONSON, S. (1991). Identification of the hepatocyte growth factor receptor as the c-met protooncogene product. Science 251, 802-804. CROCE,C. M. & KOPROWSKI, H. (1974). Somatic cell hybrids between mouse peritoneal macrophages and SV40 transformed human cells. 1. Positive control of the transformed phenotype by the human chromosome 7 carrying the SV-40 genome. J. Exp. M e d . 140, 1221-1229. 10
H G E 55
216
B.LAGUDAAND
OTHERS
A. p . 8~ VOGELSTEIN, B. (1983). A technique for radiolabelling DNA restriction endonuclease fragments to high specific activity. Anal. Biochem. 132, 6-13. GHERARDI, E. 8~ STOKER,M. (1990). Hepatocytes and scatter factor. Nature 346, 228. GOHDA,E., TSUBOUCHI, H., NAKAYAMA, H., HIRONO,S., SAKIYAMA, O., TAKAHASHI, K., MIYAZAKI, H., S. & DAIKUHARA, Y. (1988). Purification and partial characterization of hepatocyte growth HASHIMOTO, factor from plasma of a patient with fulminant hepatic failure. J. Clin. Invest. 81, 414-419. HEISTERKAMP, N., GROFFEN,J . , STEPHENSON, J . R . , SPURR,N.K., GOODFELLOW, P . N . , SOLOMON, E., CARRITT, B. & BODMER, W. F. (1982). Chromosomal localization of human cellular homologues of two viral oncogenes. Nature 299, 747-749. HOBART, M. J . , RABBITTS,T. H., GOODFELLOW, P. N., SOLOMON, E., CHAMBERS, S., SPURR,N. & POVEY, S. (1981). Immunoglobulin heavy chain genes in humans are located on chromosome 14. Ann. Hum. Genet. 45, 33 1-335. HUMAN GENEMAPPING 10 . (1989). Tenth International Workshop on Human Gene Mapping. Cytogenet. Cell Genet. 51, Nos. 1 4 . Karger Publishers Inc. JONES, E. A., GOODFELLOW, P. N., KENNETT, R. H. & BODMER, W. F. (1976). The independent expression of HLA and b2 microglobulin on human-mouse hybrids. S o m t . Cell Genet. 2, 483496. KAN,M., ZHANG, G., ZARNEGAR, R., MICHALOPOULOS,G., MYOKEN,Y., MCKEEHAN, W. & STEVENS, J . (1991). Hepatocyte growth factor/hepatopoietin A stimulates the growth of rat kidney proximal tubule epithelial cells (RPTE), rat nonparenchymal liver cells, human melanoma cells, mouse keratinocytes and stimulates anchorage-independent growth of SV-40 transformed RPTE. Biochem. Biophys. Res. Commun. 174,331-337. KIELTY,C. M., POVEY, S. & HOPKINSON, D. A. (1982). Regulation of expression of liver-specific enzymes. 111. Further analysis of a series of rat hepatoma x human somatic cell hybrids. Ann. Hum. Genet. 46, 307-327. KINOSHITA, T., TASHIRO,K. & NAKAMURA, T. (1989). Marked increase of HGF mRNA in non-parenchymal liver cells of rats treated with hepatotoxins. Biochem. Biophys. Res. Commun. 165, 1229-1234. NAKAMURA, T., NAWA,K. & ICHIHARA, A. (1984). Partial purification and characterization of hepatocyte growth factor from serum of hepatectomized rats. Biochem. Biophys. Res. Commun. 122, 1450-1459. NAKAMURA, T., NISHIZAWA, T., HAGIYA,M., SEKI,T., SHIMONISHI, M., SUGIMURA, A., TASHIRO, K. & SHIMIZU, S. (1989). Molecular cloning and expression of human hepatocyte growth factor. Nature 342, 440443. RUBIN,J. S., CHAN,A. M-L., BOTTARO, D. P., BURGESS, W. H., TAYLOR, W. G., CECH, A. C., HIRSCHFIELD, D. P. W. & AARONSON, S. A. (1991). A broad-spectrum human lung fibroblastW., WONG,J., MIKI, T., FINCH, derived mitogen is a variant of hepatocyte growth factor. Proc. Natl. Acad. Sci. USA 88, 415-419. SAMBROOK, J., FRITSCH, E. F. & MANIATIS,T. (1989). Molecular Cloning: A Laboratory Manual, 2nd edn. New York : Cold Spring Harbor Press. H. (1986). Human serum does contain a high SELDEN, C., JOHNSTONE, R., DARBY,H., GUPTA,S. & HODGSON, molecular weight hepatocyte growth factor : studies pre- and post-hepatic resection. Biochem. Biophys. Res. Commun. 139, 361-366. SELDEN,C., JONES, M., WADE,D. & HODGSON, H. (1990). Hepatotropin mRNA expression in human foetal liver development and in liver regeneration. FEBS Lett. 270, 81-84. SOLOMON, E., SWALLOW, D., BURGESS, S. & EVANS,L. (1979). Assignment of the human acid a-glucosidase gene (aGLU) to chromosome 17 using somatic cell hybrids. Ann. Hum. Genet. 42, 275-281. SPURR,N. K., DURBIN,H., SHEER,D., PARKAR, M., BOBROW, L. & BODMER, W. F. (1986). Characterization and chromosomal assignment of a human cell surface antigen defined by the monoclonal antibody AUAI. Int. J. Cancer 38, 631-636. SWALLOW,D.M., SOLOMON, E. & PAJUNEN, L. (1977). Immunochemical analysis of the N-acetyl hexosaminidases in human-mouse hybrids made using a double selective system. Cytogenet. Cell Genet. 18, 136-148. VAN HEYNINQEN, V., BOBROW, M., BODMER, W. F., GARDINER, S. E., POVEY, S. & HOPKINSON, D. A. (1975). Chromosome assignment of some human enzyme loci : mitochondria1 malate dehydrogenase to 7, mannose phosphate isomerase and pyruvate kinase to 15 and probably, esterase D to 13. Ann. Hum. Genet. 38, 295-303. WHITEHEAD, A. S., SOLOMON, E., CHAMBERS, S., BODMER, W. F., POVEY, S. & FEY,G. (1982). Assignment of the structural gene for the third component of human complement to chromosome 19. Proc. Natl. Acad. Sci. USA 79, 5012-5025. ZARNEOAR, R. & MICHALOPOULOS,G. ( 1989). Purification and biological characterization of human hepatopoietin A, a polypeptide growth factor for hepatocytes. Cancer Res. 49, 3314-3320. FEINBERQ,
