Evidence for the involvement of GM-CSF and FMS in the deletion (5q) in myeloid disorders

The cytogenetics of childhood leukemia: clinical and biologic implications

Cytogenetic studies have revealed a broad spectrum of abnormalities in the chromosomal make-up of human leukemic cells. These abnormalities are acquired during the process of malignant transformation within the neoplastic clone and reflect the genetic lesions and ablations that have occurred. Because cytogenetic abnormalities are tightly linked to the molecular events that lead to leukemogenesis, it is not surprising that these features correlate with immunophenotypic and morphologic features of the leukemic cells, as well as with the clinical characteristics of children at diagnosis and their responsiveness to therapy. Molecular analysis of the disordered structure or disrupted regulation of genes located at critical chromosomal breakpoints in leukemic cells should continue to provide important insight into normal and aberrant hematopoietic cell function.

Chromosome study of 85 patients with myelodysplastic syndrome

We studied bone marrow chromosomes in 85 consecutive patients with myelodysplastic syndrome (MDS). Fifty-seven (67%) had a clone with an abnormal karyotype at diagnosis. Eight had secondary MDS, all with abnormal karyotypes. The frequency of abnormal karyotypes in the primary MDS was 64.9%. During subsequent follow-up, five patients acquired chromosome abnormalities; thus, at the end of the study, 72.0% of patients had an abnormal karyotype. The most frequent chromosome abnormalities were 5q-, +8, -7, -5, and -22. Forty patients (i.e., 70% of those with an abnormal karyotype and 47% of the whole group) had one of the karyotype abnormalities associated with secondary MDS or acute nonlymphocytic leukemia; in other words, 5q- or -5, or -7. Of all patients, 21.1% progressed into ANLL. Unfavorable prognostic factors associated with the risk of evolution into ANLL and with shorter overall survival were the presence of greater than 5% of bone marrow blasts, major chromosome abnormalities, and monosomy 7.

The human as an experimental system in molecular genetics

There are compelling reasons for choosing to develop the human as the highest-order experimental system in genetics: an obvious social context that stirs interest, wide medical observation of the population that permits identification of an abundance of genetic defects, and our ability to perceive in the human subtle or complex variations that may not be observable in other species. Various lines of genetic inquiry that are based on research in other systems--cytogenetic analysis, biochemical studies, mapping of defective loci by linkage analysis in affected families, and in vitro techniques such as the creation of transgenic organisms--complement and enrich each other. New phenomena that would not have been predicted from investigations in other organisms have been found in humans, such as the discovery of the "giant" Duchenne muscular dystrophy gene and the identification of recessive cancer genes. Genetic research is yielding insights into human biology that are raising new possibilities for therapy and prevention of disease, as well as challenges to society in the form of ethical decisions about the appropriate application of genetic information.

Inversion of chromosome 5 long arm in region of cell growth gene cluster in hematologic disorders

Inversions of the long (q) arm of chromosome #5 are reported in five cases with hematologic disorders. Inversion of 5q with breakpoints in bands 5q13 and 5q33 was found in two cases with lymphoid malignancy and in two cases of myeloid hematologic malignancy. Because an inversion of 5q with breakpoints in 5q22 and 5q33 was also found in a case with myeloproliferative syndrome, the common denominator in these five cases was band 5q33. An extraordinary cluster of genes affecting cell growth and differentiation is present on 5q and may be altered by the chromosome rearrangement of 5q in hematologic disorders.

Haemopoietic growth factors

Erythropoietin, GM-colony-stimulating factor and G-colony-stimulating factor are the first recombinant haemopoietic growth factors to reach clinical use. There are a number of additional haemopoietic regulators that have now been cloned and are being mass-produced with a view to clinical use. The next decade should witness exciting advances in the clinical treatment of haematological diseases and infections that will be comparable with those that were seen last with the introduction of effective treatments for pernicious anaemia.

A zinc finger-encoding gene coregulated with c-fos during growth and differentiation, and after cellular depolarization

Egr-1 is an early growth response gene that displays fos-like induction kinetics in fibroblasts, epithelial cells, and lymphocytes following mitogenic stimulation. Sequence analysis of murine Egr-1 cDNA predicts a protein with three DNA binding zinc fingers. The human EGR1 gene maps to chromosome 5 (bands 5q23-31). Egr-1 mRNA increases dramatically during cardiac and neural cell differentiation, and following membrane depolarization both in vitro and in vivo. Thus, Egr-1 and c-fos are often coregulated with strikingly similar kinetics. These results, in conjunction with the Egr-1 primary structure, suggest that Egr-1 may function as a transcriptional regulator in diverse biological processes.

Primary structure of c-kit: relationship with the CSF-1/PDGF receptor kinase family--oncogenic activation of v-kit involves deletion of extracellular domain and C terminus

The protein kinase domains of v-kit, the oncogene of the acute transforming feline retrovirus HZ4-FeSV (HZ4-feline sarcoma virus), CSF-1R (macrophage colony stimulating factor receptor) and PDGFR (platelet derived growth factor receptor) display extensive homology. Because of the close structural relationship of v-kit, CSF-1R and PDGFR we predicted that c-kit would encode a protein kinase transmembrane receptor (Besmer et al., 1986a; Yarden et al., 1986). We have now determined the primary structure of murine c-kit from a DNA clone isolated from a brain cDNA library. The nucleotide sequence of the c-kit cDNA predicts a 975 amino acid protein product with a calculated mol. wt of 109.001 kd. It contains an N-terminal signal peptide, a transmembrane domain (residues 519-543) and in the C-terminal half the v-kit homologous sequences (residues 558-925). c-kit therefore contains the features which are characteristic of a transmembrane receptor kinase. Comparison of c-kit, CSF-1R and PDGFR revealed a unique structural relationship of these receptor kinases suggesting a common evolutionary origin. The outer cellular domain of c-kit was shown to be related to the immunoglobulin superfamily. The sites of expression of c-kit in normal tissue predict a function in the brain and in hematopoietic cells. N-terminal sequences which include the extracellular domain and the transmembrane domain as well as 50 amino acids from the C-terminus of c-kit are deleted in v-kit. These structural alterations are likely determinants of the oncogenic activation of v-kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Nuclear proteins interacting with the promoter region of the human granulocyte/macrophage colony-stimulating factor gene

The gene for human granulocyte/macrophage colony-stimulating factor (GM-CSF) is expressed in a tissue-specific as well as an activation-dependent manner. The interaction of nuclear proteins with the promoter region of the GM-CSF gene that is likely to be responsible for this pattern of GM-CSF expression was investigated. We show that nuclear proteins interact with DNA fragments from the GM-CSF promoter in a cell-specific manner. A region spanning two cytokine-specific sequences, cytokine 1 (CK-1, 5' GAGATTCCAC 3') and cytokine 2 (CK-2, 5' TCAGGTA 3') bound two nuclear proteins [nuclear factor (NF)-GMa and NF-GMb] from GM-CSF-expressing cells in gel retardation assays. NF-GMb was inducible with phorbol 12-myristate 13-acetate and accompanied induction of GM-CSF message. NF-GMb was absent in cell lines not producing GM-CSF, some of which had other distinct binding proteins. NF-GMa and NF-GMb eluted from a heparin-Sepharose column at 0.3 and 0.6 M KCl, respectively. We hypothesize that the sequences CK-1 and CK-2 bind specific proteins and regulate GM-CSF transcription.

Association of the Philadelphia chromosome and 5q- in secondary blood disorder

A patient developed a secondary blood disorder 7 years after radiotherapy for a gastric lymphoma. The initial myelodysplastic syndrome evolved to a myeloproliferative phase with transient polycythemia, progressive thrombocythemia, and hyperleukocytosis. Chromosome analysis performed in the terminal phase showed del(5)(q13q31),t(9;22)(q34;q11), and a complex rearrangement involving chromosomes #2 and #3. A correlation between chromosomal abnormalities and hematologic findings could be established. In this case, we have assumed that the Philadelphia translocation is a late event, due to prior mutagen exposure, and its association with a common secondary abnormality (5q-), followed by a progressively developing myeloproliferative phase. Furthermore, the association of Ph and 5q- in a single clone seems to indicate that the same stem cell is affected by these two abnormalities.

The CD14 monocyte differentiation antigen maps to a region encoding growth factors and receptors

CD14 is a myelomonocytic differentiation antigen expressed by monocytes, macrophages, and activated granulocytes and is detectable with the monoclonal antibodies MO2, MY4, and LeuM3. Analyses of complementary DNA and genomic clones of CD14 show that it has a novel structure and that it maps to chromosome 5 within a region containing other genes encoding growth factors and receptors; it may therefore represent a new receptor important for myeloid differentiation. In addition, the CD14 gene is included in the "critical" region that is frequently deleted in certain myeloid leukemias.

Molecular analysis of the cDNA for human SPARC/osteonectin/BM-40: sequence, expression, and localization of the gene to chromosome 5q31-q33

Human cDNA clones encoding the extracellular calcium-binding, acidic glycoprotein known as SPARC, osteonectin, or BM-40 were isolated from a placental cDNA library. Two polyadenylated transcripts of 2.2 and 3.0 kb were detected in human tissues and cultured cells by Northern blot analysis, and cDNAs for both transcripts were characterized. The 2133-bp sequence of the more abundant (major) transcript contains an open reading frame for 303 amino acids. The deduced polypeptide has extensive amino acid sequence identity with mouse SPARC. The larger and minor 3.0-kb cDNA has an identical coding region but utilizes a downstream polyadenylation signal. Gene localization studies have revealed a single chromosomal site at 5q31-q33 by somatic cell hybrid analysis and in situ chromosomal hybridization. Furthermore, pulsed-field gel electrophoresis of human genomic DNA cleaved with different rare-cutting restriction enzymes and hybridized with SPARC cDNA probes revealed single or double fragments of less than 50 to about 150 kb. The evidence is consistent with a single locus for SPARC in humans. The gene was found to be differentially expressed in many human tissues and in an osteogenic sarcoma, but not in other transformed cells.

Hematologic and clinical features of patients with chromosome 5 monosomy or deletion (5q)

This paper analyzes the hematologic features and outcome of 13 patients with chromosome 5 abnormalities (monosomy 5 or deletion of 5q), either isolated or with additional anomalies. Among four patients with isolated del (5q), two had a stable refractory macrocytic anemia with thrombocytosis (5q-syndrome). All nine patients with complex karyotypes had acute leukemia or refractory anemia with excess of blasts in acute transformation; two cases were TdT-positive, with a lymphoid or a mixed phenotype. In seven patients, preleukemia preceded overt leukemia, and in six, a prior therapeutic, or occupational exposure to mutagens/carcinogens had occurred. Additional chromosome 7 abnormalities were seen in four cases. The median survival of patients with complex karyotypes was 19 months from the time of diagnosis of the hematologic disorder and 5 months from the time of identification of the chromosome 5 abnormality. Pathogenetic implications of the chromosome 5 monosomy or del (5q) through a proto-oncogene activation and the putative hemopoietic stem cell involvement in a clonal disease are discussed.

The production of myeloid blood cells and their regulation during health and disease

The regulation of myelopoiesis in vivo most likely entails a complex set of interactions between cell-derived biomolecules and their target cells: hematopoietic stem and progenitor cells and accessory cells. Stimulating and suppressing factors have been characterized through in vitro studies, and their mechanisms of action in vitro and in vivo have begun to be elucidated. Among those factors being studied are the hematopoietic colony-stimulating factors (CSF): interleukin-3 (multi-CSF), granulocyte-macrophage-CSF, granulocyte-CSF, and macrophage-CSF; other molecules include erythropoietin, B-cell-stimulating factor-1, interleukin-1, interleukin-2, prostaglandin E, leukotrienes, acidic ferritins, lactoferrin, transferrin, the interferons-gamma, -alpha, and -beta, and the tumor necrosis factors-alpha and -beta (lymphotoxin). These factors interact to modulate blood cell production in vitro and in vivo. The proposed review characterizes these biomolecules biochemically and functionally, including receptor-ligand interactions and the secondary messengers within the cell which mediate their functional activity. The production and action of the molecules are described under conditions of hematopoietic disorders, as well as under normal conditions. Studies in vitro are correlated with studies in vivo using animal models to give an overall view of what is known about these molecules and their relevance physiologically and pathologically.

Oncogenes and human leukemias

Eukaryotic cells contain a family of genes termed "cellular oncogenes" or "proto-oncogenes," thought to regulate normal cell growth and development. In some circumstances, such as following transduction by retroviruses, activation of these genes causes tumors and leukemias in animals. Possible mechanisms of cellular oncogene activation include: 1) DNA point mutation, deletion or insertion, 2) gene amplification, 3) gene activation by internal rearrangement, chromosomal translocation or promoter insertion, 4) recombinative events resulting in the formation of novel chimeric genes, and others. In this review, we consider data which implicates cellular oncogene activation in the pathogenesis of leukemia in humans. We discuss possible mechanisms by which oncogene activation may induce leukemias, as well as potential diagnostic and therapeutic implications.

A variant t(X;15)(p11;q22) translocation in acute promyelocytic leukemia

Nonrandom reciprocal translocations involving chromosomes #15 and #17 are characteristic anomalies in a great majority of cases of acute promyelocytic leukemia (APL). Other complex translocations in APL that invariably involve chromosome #17 also have been described. We describe a patient with clinical and morphologic characteristics of APL but with a previously undescribed acquired karyotype, t(X;15)(p11;q22). This is the first translocation in APL described in which chromosome #17 is not involved. Although a comparative structure/function analysis of potentially relevant genes to the translocation breakpoints in both t(X;15) and t(15;17) APL showed no major alterations, the enhanced expression of the c-Ki-ras oncogene observed in t(X;15) APL supports the concept of heterogeneity in APL at the cytogenetic and molecular levels.

Human gene coding for granulocyte-colony stimulating factor is assigned to the q21-q22 region of chromosome 17

Granulocyte-colony stimulating factor (G-CSF) is a member of colony stimulating factors which regulate the proliferation and differentiation of hematopoietic progenitor cells. A full-length cDNA clone coding human G-CSF was used as a hybridization probe to detect homologous sequence in human-mouse somatic cell hybrids, flow-sorted human chromosomes, and in situ human metaphase chromosomes. The results indicate that the gene encoding human G-CSF is on the q21-q22 region of chromosome 17, which is involved in translocation of t(15;17) (q23;21) in human acute promyelocytic leukemia.

Human proto-oncogene c-kit: a new cell surface receptor tyrosine kinase for an unidentified ligand

Structural features of v-kit, the oncogene of HZ4 feline sarcoma virus, suggested that this gene arose by transduction and truncation of cellular sequences. Complementary DNA cloning of the human proto-oncogene coding for a receptor tyrosine kinase confirmed this possibility: c-kit encodes a transmembrane glycoprotein that is structurally related to the receptor for macrophage growth factor (CSF-1) and the receptor for platelet-derived growth factor. The c-kit gene is widely expressed as a single, 5-kb transcript, and it is localized to human chromosome 4 and to mouse chromosome 5. A c-kit peptide antibody permitted the identification of a 145,000 dalton c-kit gene product that is inserted in the cellular plasma membrane and is capable of self-phosphorylation on tyrosine residues in both human glioblastoma cells and transfected mouse fibroblasts. Our results suggest that p145c-kit functions as a cell surface receptor for an as yet unidentified ligand. Furthermore, carboxy- and amino-terminal truncations that occurred during the viral transduction process are likely to have generated the transformation potential of v-kit.

Translocation t(3;5)(q24;q32) in two acute nonlymphocytic leukemias

A translocation t(3;5)(q24;q32) has been detected in two patients with acute nonlymphocytic leukemia (ANLL), one with M2 and the other with M5. This translocation may be a new example of a nonrandom chromosome change in ANLL.

Frequent c-fms activation by proviral insertion in mouse myeloblastic leukaemias

Retroviruses lacking oncogenes can induce tumours in animals, and the tumour cells are frequently found to contain proviral DNA inserted next to a proto-oncogene, which is thus placed under the regulatory control of the retroviral long terminal repeat (LTR). This altered regulation leads to overexpression of the proto-oncogene, which presumably contributes to the growth properties of the tumour cells. fim-2 has been described as a retroviral integration site frequently and specifically involved in murine myeloblastic leukaemias induced in vivo or in vitro by the replication-competent Friend murine leukaemia virus (F-MuLV). Here we report that fim-2 spans the 5'-end of the murine proto-oncogene c-fms, known to code for a transmembrane glycoprotein with tyrosine kinase activity probably identical to the receptor of the haemopoietic growth factor, monocyte-macrophage colony-stimulating factor (M-CSF or CSF-1). Proviral integration in the fim-2 region results in a high expression of a normal sized c-fms messenger RNA. We also observe that some tumours have lost the fim-2/c-fms germ line allele. These results provide the first evidence for the presumed involvement of c-fms in myelomonocytic leukaemias.

Diagnosis of genetic disease using recombinant DNA. Supplement

Recombinant DNA methodology has greatly increased our knowledge of the molecular pathology of the human genome at the same time as providing the means to diagnose inherited disease as the DNA level. We present here a list of recent reports of both direct and indirect analysis of human inherited disease which is intended to serve as a guide to current molecular genetic approaches to diagnostic medicine.

The iatrogenic leukaemias induced by radio- and/or chemotherapy

A short review, limited to recently published series of data, has been compiled on the 'therapy-induced' secondary malignancies. Their frequency, peak of incidence, haematological and clinical criteria, the influence of age, treated primary disease, choice of drug(s) and modality of prescription and the role of genetic and environmental factors are analyzed. The risk varies between 0.6 and 20.5% after different treatment forms. Some suggestions for the choice of treatment of chronic malignant disorders, and for the design of future epidemiological studies are given.

A myeloproliferative disease in two infants associated with eosinophilia and chromosome t(1;5) translocation

Two children are described who presented at the age of 5 and 7 months with anaemia, a high white cell count with eosinophilia and thrombocytopenia. Both children had an identical balanced translocation t(1;5)(q23;q33) and no evidence of a constitutional abnormality. The response to treatment of one child was poor, the other remains well on therapy. This translocation has not been previously reported and is likely to represent a subclass of myeloproliferative disorder analogous to the monosomy 7 syndrome, although less common. The previous literature of acquired chromosome abnormalities involving chromosomes 1 and 5 is reviewed.

The interleukin 3 gene is located on human chromosome 5 and is deleted in myeloid leukemias with a deletion of 5q

The gene IL-3 encodes interleukin 3, a hematopoietic colony-stimulating factor (CSF) that is capable of supporting the proliferation of a broad range of hematopoietic cell types. By using somatic cell hybrids and in situ chromosomal hybridization, we localized this gene to human chromosome 5 at bands q23-31, a chromosomal region that is frequently deleted [del(5q)] in patients with myeloid disorders. By in situ hybridization, IL-3 was found to be deleted in the 5q-chromosome of one patient with refractory anemia who had a del(5)(q15q33.3), of three patients with refractory anemia (two patients) or acute nonlymphocytic leukemia (ANLL) de novo who had a similar distal breakpoint [del(5)(q13q33.3)], and of a fifth patient, with therapy-related ANLL, who had a similar distal breakpoint in band q33 [del(5)(q14q33.3)]. Southern blot analysis of somatic cell hybrids retaining the normal or the deleted chromosome 5 from two patients with the refractory anemia 5q- syndrome indicated that IL-3 sequences were absent form the hybrids retaining the deleted chromosome 5 but not from hybrids that had a cytologically normal chromosome 5. Thus, a small segment of chromosome 5 contains IL-3, GM-CSF (the gene encoding granulocyte-macrophage-CSF), CSF-1 (the gene encoding macrophage-CSF), and FMS (the human c-fms protooncogene, which encodes the CSF-1 receptor). Our findings and earlier results indicating that GM-CSF, CSF-1, and FMS were deleted in the 5q-chromosome, suggest that loss of IL-3 or of other CSF genes may play an important role in the pathogenesis of hematologic disorders associated with a del(5q).

The human hematopoietic colony-stimulating factors

The complementary DNAs and genes encoding the four major human myeloid growth factors--granulocyte colony-stimulating factor, macrophage colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and interleukin-3--have all been molecularly cloned. These DNA clones have proved valuable for studying the molecular biology of these important regulatory molecules as well as for the large-scale production of the recombinant growth factor proteins. These advances have led to a much better understanding of the role of the myeloid growth factors in regulating hematopoiesis in vivo that should soon find practical application in clinical medicine.

The physical map of Mus musculus chromosome 11 reveals evolutionary relationships with different syntenic groups of genes in Homo sapiens

The physical localization of sequences homologous to three cloned genes was determined by in situ hybridization to metaphase chromosomes. Previous work had assigned the skeletal myosin heavy chain gene cluster (Myh), the functional locus for the cellular tumor antigen p53 (Trp53-1), and the cellular homologue of the viral erb-B oncogene (Erbb) to Mus musculus chromosome 11 (MMU11). Our results provide regional assignments of Myh and Trp53-1 to chromosome bands B2----C, and of Erbb to bands A1----A4. Taken together with in situ mapping of three other loci on MMU 11 (Hox-2 homeobox-containing gene cluster, the Sparc protein, and the Colla-1 collagen gene), which have been reported elsewhere, these data allowed us to construct a physical map of MMU11 and to compare it with the linkage map of this chromosome. The map positions of the homologous genes on human chromosomes suggest evolutionary relationships of distinct regions of MMU11 with six different human chromosome arms: 1p, 5q, 7p, 16p, 17p, and 17q. The delineation of conserved chromosome regions has important implications for the understanding of karyotype evolution in mammalian species and for the development of animal models of human genetic diseases.

Cytogenetic characteristics of therapy-related acute nonlymphocytic leukaemia, preleukaemia and acute myeloproliferative syndrome: correlation with clinical data for 61 consecutive cases

Cytogenetic studies were performed on a new series of 23 patients with therapy-related acute non-lymphocytic leukaemia, preleukaemia or an acute myeloproliferative syndrome. In our total series of now 61 cases studied by chromosome banding techniques, at least one of the abnormalities -7, 5q-, 7q- or -5 or some related unbalanced translocations, primarily -7, +t(1q7p), was observed in 40 patients. The critical region for the deletions of chromosome no. 5 comprises bands 5q22 to 5q33 and of chromosome no. 7 bands distal to 7q22. The third most frequently involved chromosome was no. 21, rearranged at band 21q22 in the three patients with 21q+ and in one patient with 21q-. An i(21q) was observed in two patients, a -21 in four patients and a -22, +t(21q22q) and a -5, -21, +t(5p21q) in one patient each. Other characteristic abnormalities included total loss or rearrangements of the short arm of chromosome no. 17, observed in nine patients. One patient had a -12, three others had rearrangements resulting in a partial or total loss of the short arm of chromosome no. 12. A 19q+ with translocation to band 19q13 was observed in three cases, a -18 in three cases and a 3p- in four cases. Thirty-one patients with multiple chromosome aberrations experienced a significantly shorter survival as compared to 13 patients with a normal karyotype (P = 0.02) and 17 patients with one single chromosome aberration (P less than 0.01).

The Wellcome Foundation lecture, 1986. The molecular control of normal and leukaemic granulocytes and macrophages

The development of semisolid culture methods supporting the clonal proliferation and maturation of granulocytes and macrophages led to the discovery of a group of specific glycoproteins, the colony-stimulating factors (CSFs), whose function it is to control the proliferation and functional activity of granulocytes, macrophages and associated blood cells. The four known CSFs in the mouse and man have been purified and complementary DNAs (cDNAs) for each have been cloned. The injection of bacterially synthesized recombinant CSF into mice has demonstrated that these CSFs can function in vivo to regulate granulocyte and macrophage formation. A major physiological role played by these CSFs is to control resistance to invading microorganisms through mechanisms capable of extremely rapid activation. Because the CSFs are the only known proliferative factors for these cells, the CSFs are involved in the initiation and the emergence of myeloid leukaemia but, conversely, at least one of the CSFs, G-CSF, is able to suppress myeloid leukaemic populations because of the ability of the CSFs to initiate differentiation commitment in responding granulocytic and macrophage populations. The CSFs are promising agents for clinical use in the treatment of infections in patients with depressed granulocyte-macrophage formation and possibly in the management of some types of myeloid leukaemia.

Assignment of CSF-1 to 5q33.1: evidence for clustering of genes regulating hematopoiesis and for their involvement in the deletion of the long arm of chromosome 5 in myeloid disorders

The CSF-1 gene encodes a hematopoietic colony-stimulating factor (CSF) that promotes growth, differentiation, and survival of mononuclear phagocytes. By using somatic cell hybrids and in situ hybridization, we localized this gene to human chromosome 5 at bands q31 to q35, a chromosomal region that is frequently deleted [del(5q)] in patients with myeloid disorders. By in situ hybridization, the CSF-1 gene was found to be deleted in the 5q- chromosome of a patient with refractory anemia who had a del(5)(q15q33.3) and in that of a second patient with acute nonlymphocytic leukemia de novo who had a similar distal breakpoint [del(5)(q13q33.3)]. The gene was present in the deleted chromosome of a third patient, with therapy-related acute nonlymphocytic leukemia, who had a more proximal breakpoint in band q33 [del(5)(q22q33.1)]. Hybridization of the CSF-1 probe to metaphase cells of a fourth patient, with acute nonlymphocytic leukemia de novo, who had a rearrangement of chromosomes 5 and 21 [ins(21;5)(q22;q31.3q33.1)] resulted in labeling of the breakpoint junctions of both rearranged chromosomes; this suggested that CSF-1 is located at 5q33.1. Thus, a small segment of chromosome 5 contains GM-CSF (the gene encoding the granulocyte-macrophage CSF), CSF-1, and FMS, which encodes the CSF-1 receptor, in that order from the centromere; this cluster of genes may be involved in the altered hematopoiesis associated with a deletion of 5q.

Human-fms gene is retained in acute lymphoblastic leukemia cells with del(5)(q32)

Cytogenetic and molecular investigations of NALM 6 cells (a pre-B-lymphoblastic acute leukemia cell line) revealed them to contain both alleles of the c-fms gene, though the cells had chromosomal changes of 5q- and 12p+. The amount of DNA fragments hybridized to the 1.4 kb PstI/PstI v-fms probe in the NALM 6 cells was approximately the same, when compared with cells of an Epstein-Barr virus-transformed lymphoblastoid cell line with a normal karyotype. Chromosome banding analysis revealed that the breakpoint of the 5q- in the NALM 6 cells was at the proximal portion of the 5q32 band. Chromosomal in situ hybridization of NALM 6 cells showed a significant accumulation of grains on the terminal portions of the abnormal 5q- chromosomes (5q32), as well as on the normal chromosomes #5 with a peak at 5q32-q33. These findings indicate that the human c-fms gene is not deleted in the lymphoblastic leukemia cells with a 5q- studied by us and that it does not show rearrangement or amplification. Thus, the results indicate that a difference in the dosage of the c-fms gene in acute lymphoblastic leukemia cells with the 5q- versus that in cells with the 5q- change in nonlymphocytic neoplasia; in the latter a hemizgosity of the c-fms gene has been suggested.

Comparative effects in vivo of recombinant murine interleukin 3, natural murine colony-stimulating factor-1, and recombinant murine granulocyte-macrophage colony-stimulating factor on myelopoiesis in mice

Purified murine colony-stimulating factors (CSF) recombinant interleukin 3 (IL-3), natural CSF-1, and recombinant granulocyte-macrophage (GM) CSF were assessed in vivo for their effects on BDF1 mouse bone marrow and spleen granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells in untreated mice and in mice pretreated with purified iron-saturated human lactoferrin (LF). The CSF and LF preparations did not contain detectable endotoxin (less than 0.1 ng). Mice pretreated with LF were more sensitive to the effects of CSF. In mice pretreated with LF, 2,000 U IL-3 or 20,000 U CSF-1 significantly enhanced the cycling status and absolute numbers of all progenitors, whereas 20,000 U GM-CSF significantly increased the cycling status of CFU-GM and CFU-GEMM, but had no effect on cycling of BFU-E or on numbers of any of the progenitors. The effects of CSF in mice pretreated with LF were not mimicked by 0.1-100 ng E. coli lipopolysaccharide.

Growth factors, oncogenes, and multistage carcinogenesis

This paper presents evidence that the full repertoire of cellular genes involved in the carcinogenic process is several times larger than that of the known list of proto-oncogenes. Furthermore, this repertoire includes genes whose normal function is related to growth stimulation, as well as genes whose normal function is to inhibit growth or induce terminal differentiation. Multistage carcinogenesis probably results from a complex series of changes in both categories of genes. Despite this complexity, carcinogenesis can be conceived in terms of disturbances in biochemical functions that normally control the expression or function of growth factors, receptors, and pathways of signal transduction. Several protein kinases play a central role in the process of signal transduction. Our laboratory has recently isolated cDNA clones for the enzyme protein kinase C (PKC). These clones should be useful for clarifying the role of PKC in growth control and tumor promotion. Finally, the existence of genes whose normal function is to inhibit cell growth provides a rationale for new strategies of cancer prevention and treatment.

Monosomy 7 in granulocytes and monocytes in myelodysplastic syndrome

Monosomy for all or part of chromosome 7 in bone marrow mitoses of some patients with myelodysplastic syndrome or acute nonlymphocytic leukemia has been associated with a defect in granulocyte function. To study which blood-cell lineages are affected by the monosomy, we used chromosome 7-specific DNA probes in Southern blotting experiments on DNA derived from specific cell fractions isolated from the blood of five patients. As judged by the presence or absence of two different alleles for restriction-fragment-length polymorphisms, lymphocytes of all five patients were shown to have two different chromosomes 7. Granulocytes were affected by the chromosomal abnormality in four patients (No. 1, 2, 4, and 5) and unaffected in one (No. 3). Chemotaxis was normal in Patient 3 and impaired in Patients 4 and 5. Monocytes were affected by the monosomy in two of three patients (No. 2 and 3) and mainly unaffected in one (No. 1). Thus, the granulocytes and monocytes were affected differently in different patients. We conclude that mature blood cells are derived from abnormal progenitors and that there may be heterogeneity in the involvement of different cell lineages in different patients with myelodysplastic syndrome or acute nonlymphocytic leukemia. There is an association between DNA loss and functional impairment.

The role of the colony-stimulating factors in resistance to acute infections

A set of specific glycoproteins, the colony-stimulating factors, has been identified as regulating granulocyte and macrophage production and function. These colony-stimulating factors have now been purified and mass produced by recombinant technology. These versatile regulators are capable of providing the body both with an ultrarapid and sustained system for responding to infections. The granulocytes, macrophages and eosinophils involved in these responses appear likely to be key cell populations ensuring adequate resistance to acute infections and the colony-stimulating factors may prove to be valuable agents in the clinic for increasing resistance to life-threatening infections particularly in immunologically compromised patients.

Transformation by the v-fms oncogene product: an analog of the CSF-1 receptor

The product of the c-fms proto-oncogene is related to, and possibly identical with, the receptor for the macrophage colony-stimulating factor, M-CSF (CSF-1). Unlike the product of the v-erbB oncogene, which is a truncated version of the EGF receptor, the glycoprotein encoded by the v-fms oncogene retains an intact extracellular ligand-binding domain so that cells transformed by v-fms express CSF-1 receptors at their surface. Although fibroblasts susceptible to transformation by v-fms generally produce CSF-1, v-fms-mediated transformation does not depend on an exogenous source of the growth factor, and neutralizing antibodies to CSF-1 do not affect the transformed phenotype. An alteration of the v-fms gene product at its extreme carboxyl-terminus represents the major structural difference between it and the c-fms-coded glycoprotein and may affect the tyrosine kinase activity of the v-fms-coded receptor. Consistent with this interpretation, tyrosine phosphorylation of the v-fms products in membranes was observed in the absence of CSF-1 and was not enhanced by addition of the murine growth factor. Cells transformed by v-fms have a constitutively elevated specific activity of a guanine nucleotide-dependent, phosphatidylinositol-4,5-diphosphate-specific phospholipase C. We speculate that the tyrosine kinase activity of the v-fms/c-fms gene products may be coupled to this phospholipase C, possibly through a G regulatory protein, thereby increasing phosphatidylinositol turnover and generating the intracellular second messengers diacylglycerol and inositol triphosphate.

cDNA for the human beta 2-adrenergic receptor: a protein with multiple membrane-spanning domains and encoded by a gene whose chromosomal location is shared with that of the receptor for platelet-derived growth factor

We have isolated and sequenced a cDNA encoding the human beta 2-adrenergic receptor. The deduced amino acid sequence (413 residues) is that of a protein containing seven clusters of hydrophobic amino acids suggestive of membrane-spanning domains. While the protein is 87% identical overall with the previously cloned hamster beta 2-adrenergic receptor, the most highly conserved regions are the putative transmembrane helices (95% identical) and cytoplasmic loops (93% identical), suggesting that these regions of the molecule harbor important functional domains. Several of the transmembrane helices also share lesser degrees of identity with comparable regions of select members of the opsin family of visual pigments. We have localized the gene for the beta 2-adrenergic receptor to q31-q32 on chromosome 5. This is the same position recently determined for the gene encoding the receptor for platelet-derived growth factor and is adjacent to that for the FMS protooncogene, which encodes the receptor for the macrophage colony-stimulating factor.