Nerve growth factor stimulates clonal growth of human lung cancer cell lines and a human glioblastoma cell line expressing high-affinity nerve growth factor binding sites involving tyrosine kinase signaling.
The growth of a panel of 22 different human tumor, leukemia, and lymphoma cell lines was examined in a human tumor cloning assay in agar or methylcellulose and a tritiated thymidine uptake assay. The cultures were performed in the absence or presence of increasing concentrations (0.5-500 ng/ml) of nerve growth factor (NGF). The growth of 17 of the 22 cell lines was not significantly and reproducibly affected by NGF. There was minor (1.2-fold) but reproducible stimulation of clonal growth in one glioblastoma cell line (86-HG-39) by NGF, but in this cell line NGF induced no growth modulation in a tritiated thymidine uptake assay. However, clonal growth of another glioblastoma cell line (87-HG-31) and all three lung cancer cell lines tested (HTB 119, HTB 120, CCL 185) could be stimulated up to 3-fold by NGF with a dose-response relationship for the growth factor. Growth stimulation by NGF could be completely reversed by neutralizing anti-NGF antibody and by the tyrosine kinase inhibitor genistein. Evaluation of secondary plating efficiency revealed the stimulation of colony formation as representing self-renewal and not terminal differentiation. Reverse transcriptase-PCR experiments in the five responding cell lines showed expression of both low-affinity NGF receptor (glycoprotein 75) and c-trk transcripts on the mRNA level. Of the five responding cell lines, only 86-HG-39, the cell line with the lowest responsiveness, revealed low-affinity NGF receptor on the protein level; the other four cell lines with high responsiveness, including the three lung cancer cell lines, expressed no low-affinity NGF receptor as shown by fluorescence-activated cell sorter analysis and immunoprecipitation using the ME 20.4 antibody. Immunoprecipitation using anti-trk antibodies was negative in all five responding cell lines. However, binding studies with iodinated NGF showed only low-affinity binding on the 86-HG-39 cell line and only high-affinity binding on the high-responder cell lines CCL 185 and 87-HG-31. In summary, our data suggest that NGF can be operative in stimulation of clonal growth of malignant tumor cells. High-affinity but not low-affinity binding sites mediate signal transduction for clonal growth and signaling involves tyrosine kinase activity.
Oelmann
E
E
Department of Medicine/Hematology and Oncology, Benjamin Franklin Hospital (Klinikum Steglitz), Freie Universitaet Berlin, Germany.
Sreter
L
L
Schuller
I
I
Serve
H
H
Koenigsmann
M
M
Wiedenmann
B
B
Oberberg
D
D
Reufi
B
B
Thiel
E
E
Berdel
W E
WE
D001483:Base Sequence; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology; D018288:Carcinoma, Small Cell / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D019833:Genistein; D005909:Glioblastoma / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D020917:Receptor, trkA; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D007529:Isoflavones; D009414:Nerve Growth Factors; D011518:Proto-Oncogene Proteins; D017475:Receptors, Nerve Growth Factor; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D020917:Receptor, trkA; D012194:RNA-Directed DNA Polymerase