Regulation of colony-stimulating factor 1 during pregnancy.

Pregnancy results in an elevation in serum and tissue concentrations of the mononuclear phagocytic growth factor, CSF-1 (colony-stimulating factor 1). These increases are associated with an increase in the number of monocytes in the circulation, and with increases in the number of splenic macrophage precursors. In contrast to the approximately 2-fold elevation of the CSF-1 concentrations in serum and most tissues, pregnancy results in a 1,000-fold increase in the concentration of uterine CSF-1. The roughly fivefold elevation in uterine CSF-1 concentration observed at day 5 of pregnancy could be mimicked by administration of chorionic gonadotrophin in intact but not ovariectomized mice. These dramatic changes in uterine CSF-1 concentrations may indicate a role for CSF-1 in the regulation of nonmononuclear phagocytic cell types.

Factors regulating macrophage production and growth: identity of colony-stimulating factor and macrophage growth factor.

The activities of a colony-stimulating factor (CSF), which stimulates granulocyte-macrophage colony formation by mouse hemopoietic cells, and macrophage growth factor (MGF), which stimulates proliferation of activated peritoneal macrophages, have been demonstrated by various criteria to reside in the same molecular species. These criteria include occurrence in various sources and copurification of the activities in mouse L-cell-conditioned medium as well as the biological, physicochemical, and antigenic properties of the activities of L-cell-conditioned medium. CSF and MGF activities of L-cell-conditioned medium are ascribable to a glycoprotein of mol wt approximately 60,000 which migrates electrophoretically with alpha-globulin. Human urinary CSF, which also possesses MGF activity, has similar properties and can be neutralized by antiserum to highly purified L-cell medium CSF. A procedure is described for the partial purification of material from L-cell medium that has activity at 1 ng/ml in both MGF and CSF assays.

Delayed hematopoietic development in osteopetrotic (op/op) mice.

Changes in structure, cellularity, hematopoietic progenitor cell and macrophage content, and osteoclast activity were investigated in the hematopoietic organs of the colony-stimulating factor 1(CSF-1)-less osteopetrotic (op/op) mouse. The data indicated that op/op mice undergo an age-related hematopoietic recovery and resolution of osteopetrosis, suggesting that the hematopoietic system has the capacity to use alternative mechanisms to compensate for the absence of an important multifunctional growth factor, CSF-1. In young animals, op/op femurs were heavily infiltrated with bone, and marrow cellularity was significantly reduced. After 6 wk of age, there was an increase in the marrow space available for hematopoiesis. The femoral cavity of op/op mice progressively enlarged, and by 22 wk of age its appearance and marrow cellularity was comparable to that of controls. The percentage of op/op mononuclear phagocytes, defined by F4/80 antigen expression, progressively increased to normal levels by 35 wk of age. There was no difference in the incidence of both primitive and mononuclear phagocyte-committed, CSF-1-responsive progenitor cells in op/op marrow, but their femoral content was significantly reduced in young mice. During the period of reduced hematopoiesis in the marrow of young op/op mice, splenic hematopoietic activity was elevated. This mutant mouse represents a system for the study of the CSF-1-independent regulatory mechanisms involved in hematopoietic regulation.

Activation of human macrophages. Comparison of other cytokines with interferon-gamma.

Cytokines affecting mononuclear phagocytes were screened for activation of human macrophages to secrete H2O2 and kill toxoplasmas. In contrast to recombinant interferon-gamma (rIFN gamma), the following factors, tested in partially or highly purified form and over a wide range of concentrations, did not augment these functions: native interferon-alpha (nIFN alpha), rIFN alpha A, rIFN alpha D, rIFN beta, colony stimulating factor (type 1) (CSF-1), CSF for granulocytes and macrophages (GM-CSF), pluripotent CSF (p-CSF), tumor necrosis factor (TNF), native interleukin 2 (nIL-2), and rIL-2. Partially purified migration inhibitory factor (MIF) enhanced H2O2-releasing capacity submaximally without inducing antitoxoplasma activity, and warrants further study.

Specific interaction of murine colony-stimulating factor with mononuclear phagocytic cells.

L-cell colony-stimulating factor (CSF) is identical to macrophage growth factor and stimulates macrophage proliferation (Stanley et al., 1976, J. Exp. Med. 143: 631-647). The nature of the interaction of iodinated L-cell CSF (125I-CSF) with murine peritoneal exudate macrophages was studied. On incubation with 10 pM 125I-CSF at 0 degrees C, cellular binding of 125I-CSF reaches a stable maximum within 15 h. This is in contrast to the association behavior at higher temperatures. At 37 degrees C, cell-associated 125I-CSF levels reach, within 45 min, an unstable maximum which is up to 10-fold less than that occurring under the same conditions at 0 degrees C. At 0 degrees C, binding is saturated (approximately 5 X 10(4) sites/cell) at CSF concentrations of 1 nM. A comparison of binding and competition experiments indicates that iodinated L-cell CSF binds as effectively as L-cell CSF and that human urinary CSF and L-cell CSF equipotently compete for 125I-CSF binding. Specificity of the CSF-binding site is demonstrated by the failure of other known growth factors and hormones to compete for 125I-CSF binding. These studies and other findings suggest that 125I-CSF binding is restricted to macrophages and their precursors and to macrophage cell lines and that the binding site(s) is the receptor mediating the biological action of this CSF.

Distribution of cells bearing receptors for a colony-stimulating factor (CSF-1) in murine tissues.

CSF-1 is a subclass of the colony-stimulating factors that specifically stimulates the growth of mononuclear phagocytes. We used the binding of 125I-CSF-1 at 0 degrees C by single cell suspensions from various murine tissues, in conjunction with radioautography, to determine the frequency of binding cells, their identity, and the number of binding sites per binding cell. For all tissues examined, saturation of binding sites was achieved within 2 h at 2--3 x 10(-10) M 125I-CSF-1. The binding was irreversible and almost completely blocked by a 2 h preincubation with 5 x 10(-10) M CSF-1. 125I-CSF-1 binding was exhibited by 4.3% of bone marrow cells, 7.5% of blood mononuclear cells, 2.4% of spleen cells, 20.5% of peritoneal cells, 11.8% of pulmonary alveolar cells and 0.4% of lymph node cells. Four morphologically distinguishable cell types bound 125I-CSF-1: blast cells; mononuclear cells with a ratio of nuclear to cytoplasmic area (N/C) greater than 1; cells with indented nuclei; and mononuclear cells with N/C less than or equal to 1. No CSF-1 binding cells were detected among blood granulocytes or thymus cells. Bone marrow promyelocytes, myelocytes, neutrophilic granulocytes, eosinophilic granulocytes, nucleated erythroid cells, enucleated erythrocytes, and megakaryocytes also failed to bind. The frequency distribution of grain counts per cell for blood mononuclear cells was homogenous. In contrast, those for bone marrow, spleen, alveolar, and peritoneal cells were heterogeneous. The monocytes in blood or bone marrow (small cells, with either indented nuclei or with N/C greater than 1) were relatively uniformly labeled, possessing approximately 3,000 binding sites per cell. Larger binding cells (e.g., alveolar cells) may possess higher numbers of receptors. It is concluded that CSF-1 binding is restricted to mononuclear phagocytic cells and their precursors and that it can be used to identify both mature and immature cells of this series.

Macrophage colony-stimulating factor is indispensable for both proliferation and differentiation of osteoclast progenitors.

The mechanism of action of macrophage colony-stimulating factor (M-CSF) in osteoclast development was examined in a co-culture system of mouse osteoblastic cells and spleen cells. In this co-culture, osteoclast-like multinucleated cells (MNCs) were formed within 6 d in response to 10 nM 1 alpha,25(OH)2D3 added only for the final 2 d of culture. Simultaneously adding hydroxyurea for the final 2 d completely inhibited proliferation of cultured cells without affecting 1 alpha,25(OH)2D3-stimulated MNC formation. Autoradiographic examination using [3H]-thymidine revealed that osteoclast progenitors primarily proliferated during the first 4 d, whereas their differentiation into MNCs occurred predominantly during the final 2 d of culture in response to 1 alpha,25(OH)2D3. When anti-M-CSF antibody or anti-M-CSF receptor antibody was added either for the first 4 d or for the final 2 d, the MNC formation was similarly inhibited. In co-cultures of normal spleen cells and osteoblastic cells obtained from op/op mice, which cannot produce functionally active M-CSF, the lack of M-CSF either for the first 4 d or for the final 2 d failed to form MNCs in response to 1 alpha,25(OH)2D3 added for the last 2 d. These results clearly indicate that M-CSF is indispensable for both proliferation of osteoclast progenitors and their differentiation into mature osteoclasts.

Expression of the human c-fms proto-oncogene product (colony-stimulating factor-1 receptor) on peripheral blood mononuclear cells and choriocarcinoma cell lines.

The c-fms gene product is related, and possibly identical, to the receptor for the mononuclear phagocyte colony stimulating factor, CSF-1. Using antisera to a recombinant v-fms--coded polypeptide, glycoproteins encoded by the human c-fms locus were detected in mononuclear cells from normal peripheral blood and in promyelocytic HL-60 cells 24 h after induction of monocytic differentiation with phorbol ester. The 150-kD human c-fms--coded glycoprotein was expressed at the cell surface, was active as a tyrosine-specific protein kinase in vitro, and shared primary structural features with the product of the feline retroviral v-fms oncogene. A biochemically indistinguishable glycoprotein was detected in human choriocarcinoma cell lines. Like peripheral blood mononuclear cells and phorbol ester-treated HL-60 cells, the choriocarcinoma cells expressed high affinity binding sites for human CSF-1. In addition to serving as a lineage specific growth factor in hematopoiesis, CSF-1 may play a role in normal trophoblast development.

Induction of clonal monocyte-macrophage tumors in vivo by a mouse c-myc retrovirus: rearrangement of the CSF-1 gene as a secondary transforming event.

A mouse retrovirus containing the c-myc oncogene was found to induce tumors of mononuclear phagocytic cells in vivo. All tumors expressed the c-myc retroviral gene but not the endogenous c-myc gene (with one exception), and virtually all tumors were clonal with a unique proviral integration. This observation, coupled with a lag time in tumor formation, suggests that a second event, in addition to c-myc proviral integration, is necessary for the generation of neoplastic cells in vivo. All of the tumor cells expressed high levels of mRNA for both the putative colony-stimulating factor 1 (CSF-1) receptor (c-fms proto-oncogene product), as well as the c-fos proto-oncogene. Although all of the tumor cells proliferated in culture without the addition of exogenous CSF-1, which is required for the proliferation of primary macrophages partially transformed by the same c-myc retrovirus, several phenotypes were observed with respect to the expression of CSF-1 and granulocyte-macrophage CSF and to their growth factor responsiveness. The proliferation of one tumor, which secreted high levels of CSF-1, was blocked by specific anti-CSF-1 serum. This tumor was found to express altered CSF-1 mRNA and to have a DNA rearrangement at the CSF-1 locus. In this particular case, the data indicate that a CSF-1 gene rearrangement was the secondary event in development of the tumor. The pleiotropy of phenotypes among the other tumors indicated that there are a variety of other mechanisms for such secondary events which can be investigated with this system.

Constitutive c-ets2 expression in M1D+ myeloblast leukemic cells induces their differentiation to macrophages.

The expression of c-ets2 is rapidly induced in a variety of myelomonocytic cell lines as they differentiate into macrophages. We find that constitutive expression of c-ets2 in the M1D+ myeloblast leukemic cell line (M1ets2) is sufficient to push these cells to a more differentiated state. The expression of several differentiation-specific genes is upregulated in M1ets2 cells, including those encoding macrophage-specific lysozyme M and tumor necrosis factor alpha, which are involved in bacteriolytic and inflammatory processes, respectively. Transcription factors c-jun and junB, previously shown to induce partial macrophage differentiation when overexpressed in myelomonocytic leukemia cell lines, are also upregulated in M1ets2 cells. The upregulation of junB is the result of a direct interaction of Ets2 with ets binding sites of the junB promoter, since transient or constitutive Ets2 expression in M1D+ cells activates junB transcription via ets binding sites. In addition, transfection of a dominant negative mutant of Ets2, devoid of its transcriptional activation domain, greatly reduces transcriptional activities of the junB promoter in M1ets2 cells. Finally, unlike their parental M1D+ counterparts, M1ets2 cells secrete the macrophage colony-stimulating factor, CSF-1, and are able to phagocytize. Taken together, these results show that when the immature myeloid M1D+ cell line constitutively expresses c-ets2, these cells acquire different functions of mature macrophages.

Protein tyrosine phosphatase phi regulates paxillin tyrosine phosphorylation and mediates colony-stimulating factor 1-induced morphological changes in macrophages.

Removal of colony-stimulating factor 1 (CSF-1) causes macrophages to round up and to increase their expression of protein tyrosine phosphatase phi (PTP phi). This is accompanied by the disruption of focal complexes and the formation of ruffles. Here we have overexpressed wild-type (WT) PTP phi and a phosphatase-inactive (C325S) mutant in a macrophage cell line in the presence and absence of CSF-1. In the presence of CSF-1, WT PTP phi induces cell rounding and ruffle formation, while C325S PTP phi has no effect. In contrast, in CSF-1-starved cells, C325S PTP phi behaves in a dominant negative fashion, preventing rounding and ruffling. Furthermore, C325S PTP phi increases adhesion in cycling cells, while WT PTP phi enhances motility. In WT PTP phi-overexpressing cells, the focal contact protein paxillin is selectively depleted from focal complexes and specifically dephosphorylated on tyrosine. In contrast, paxillin is hyperphosphorylated in C325S PTP phi-expressing cells. Moreover, a complex containing PTP phi, paxillin, and a paxillin-associated tyrosine kinase, Pyk2, can be immunoprecipitated from macrophage lysates, and the catalytic domain of PTP phi selectively binds paxillin and Pyk2 in vitro. Although PTP phi and Pyk2 do not colocalize with paxillin in focal complexes, all three proteins are colocalized in dorsal ruffles. The results suggest that paxillin is dephosphorylated by PTP phi in dorsal ruffles, using Pyk2 as a bridging molecule, resulting in a reduced pool of tyrosine-phosphorylated paxillin available for incorporation into focal complexes, thereby mediating CSF-1 regulation of macrophage morphology, adhesion, and motility.

Functional specificity of cytoplasmic and transmembrane tyrosine kinases: identification of 130- and 75-kilodalton substrates of c-fps/fes tyrosine kinase in macrophages.

c-fps/fes encodes a 92-kDa protein-tyrosine kinase (NCP92) that is expressed at the highest levels in macrophages. To determine if c-fps/fes can mediate the action of the colony-stimulating factor 1 (CSF-1) receptor (CSF-1R) and to identify potential targets of c-fps/fes in macrophages, we have overexpressed c-fps/fes in a CSF-1-dependent macrophage cell line. A 30- to 50-fold overexpression of c-fps/fes partially released these cells from their factor dependence by a nonautocrine mechanism, and this correlated with the tyrosine phosphorylation of two proteins of 130 and 75 kDa (P130 and P75). c-fps/fes did not cause tyrosine phosphorylation or activation of CSF-1 dependent targets, including CSF-1R, Shc, and phosphatidylinositol 3-kinase, and conversely, CSF-1 did not induce tyrosine phosphorylation of P130 and P75. P75 appears to be a novel phosphotyrosyl protein, whereas P130 cross-reacts with a known substrate of v-src. P130 and P75 may be direct substrates of c-fps/fes: P130 was tightly associated with NCP92, and the src homology 2 domain of NCP92 specifically bound phosphorylated P130 and P75 but not the CSF-1-induced phosphotyrosyl proteins, consistent with the possibility that P130 and P75 are physiological targets of c-fps/fes. We conclude that although c-fps/fes can functionally substitute for CSF-1R to a certain extent, these tyrosine kinases act largely independently of each other and that P130 and P75 are novel targets whose mechanisms of action may be unrelated to the signalling pathways utilized by receptor tyrosine kinases.

Printed microfluidic filter for heparinized blood.

A simple lab-on-a-chip method for blood plasma separation was developed by combining stereolithographic 3D printing with inkjet printing, creating a completely sealed microfluidic device. In some approaches, one dilutes the blood sample before separation, reducing the concentration of a target analyte and increasing a contamination risk. In this work, a single drop (8 µl) of heparinized whole blood could be efficiently filtered using a capillary effect without any external driving forces and without dilution. The blood storage in heparin tubes during 24 h at 4 °C initiated the formation of small crystals that formed auto-filtration structures in the sample upon entering the 3D-printed device, with pores smaller than the red blood cells, separating plasma from the cellular content. The total filtration process took less than 10 s. The presented printed plasma filtration microfluidics fabricated with a rapid prototyping approach is a miniaturized, fast and easy-to-operate device that can be integrated into healthcare/portable systems for point-of-care diagnostics.

Efavirenz dissolution enhancement III: Colloid milling, pharmacokinetics and electronic tongue evaluation.

Efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor (NNRTI), is part of first-line therapy for the treatment of human immunodeficiency virus type 1 infection (HIV-1/AIDS). This drug shows relatively low oral absorption and bioavailability, as well as high intra- and inter-subject variability. Several studies have shown that treatment failure and adverse effects are associated with low and high EFV plasma concentrations, respectively. Some studies suggest different EFV formulations to minimize inter-patient variability and improve its solubility and dissolution; however, all of these formulations are complex, using for instance, cyclodextrins, dendrimers and polymeric nanoparticles, rendering them inviable industrially. The aim of this work was to prepare simple and low-cost suspensions of EFV for improvement of solubility and dissolution rate by using colloid mill, spray or freeze-drying, and characterization of the powders obtained. The results demonstrated an increase in the dissolution rate of EFV, using 0.2% of sodium lauryl sulfate (SLS) and 0.2% of hydroxypropylcellulose (HPC) or hydroxypropylmetilcellulose (HPMC) in both freeze and spray dried powders. The pharmacokinetic studies demonstrated improved pharmacokinetic parameters for the formulation containing SLS and HPC. The powders obtained, which present enhanced dissolution properties, can be incorporated in a solid dosage form for treatment of AIDS in paediatric patients with promising results.

Anti-colony-stimulating factor-1 antibody staining in primary breast adenocarcinomas correlates with marked inflammatory cell infiltrates and prognosis.

BACKGROUND: Clinical studies have shown that a marked lymphoplasmocytic reaction in breast tumors is associated with poor prognosis. Such findings raise the possibility that an inflammatory cell reaction might be a tumor-induced response that tends to promote tumor growth. PURPOSE: We assessed the expression of colony-stimulating factor-1 (CSF-1) as well as the prevalence of specific tumor-infiltrating lymphocytes and monocytes in breast tumors. METHODS: Tissue sections were obtained from archival paraffin blocks from 196 breast cancer patients. Seventy-eight percent of the women had been treated by mastectomy and 22% by lumpectomy. Median age of the patients was 54 years, and median follow-up was 7.3 years. Immunohistochemical and in situ hybridization techniques were used to characterize the specimens. RESULTS: Markedly high numbers of CD45RO-positive T- and L26-positive B-cell infiltrates were found in 13% and 17% of the tissue specimens, respectively. CSF-1 receptor-positive monocytes were detected in 48% and CD68-positive monocytes in 90% of the tumors. In turn, tumors with large fractions of CD68-positive monocytes also showed CSF-1 receptor-positive monocytes (P < .0001). CSF-1 was expressed significantly in 74% of the tumors and the CSF-1 receptor in more than 50% of the tumors. Tumors with high percentages of CSF-1 expressing cells also had marked monocyte infiltrates (P = .035). The presence of marked CD45RO-positive T-cell infiltrates and apparent nuclear staining of CSF-1 in tumor cells were associated with the more frequent occurrence of metastases (P = .02 and P = .04, respectively) and with poor survival (P = .02 and P = .03, respectively). CONCLUSIONS: Large numbers of CD45RO-positive (activated memory but noncytotoxic) T cells as well as a predominant nuclear staining pattern for CSF-1 are associated with a poor outcome in breast cancer patients. IMPLICATIONS: Nuclear retention of CSF-1 could reflect CSF-1 turnover and function in tumor cells, but new approaches are needed to establish the significance of these observations. Secreted CSF-1 appears to cause monocyte recruitment and activation, thereby modulating immune functions and potentially the expression of the CD45RO phenotype in T cells.

Expression of the macrophage growth factor, CSF-1 and its receptor c-fms by a Hodgkin's disease-derived cell line and its variants.

Expression of the macrophage colony-stimulating factor CSF-1 and its receptor, the product of the protooncogene c-fms, was detected in cell line L428, originally derived from a patient with nodular sclerosis Hodgkin's disease, and its two sublines L428KS and L428KSA. While all lines expressed membrane-associated and soluble CSF-1 proteins, L428KSA secreted 30-fold greater amounts of CSF-1 than the other cells. Three transcripts for CSF-1 (4.4, 3.7, 3.4 kilobases) were expressed in all lines and an additional 2.1-kilobase message in L428KSA. Restriction enzyme fragment analysis did not reveal any gross rearrangements of the CSF-1 gene. L428 and L428KS contained a 4.4-kilobase message for c-fms, whereas L428KSA expressed a smaller 3.8-kilobase c-fms transcript. The c-fms gene structure appeared to be unaltered in all lines by restriction enzyme fragment pattern analysis. Monoclonal anti-c-fms antibody precipitated from all cells a Mr 120,000/130,000 doublet and two lower molecular weight phosphoproteins; however, only L428KSA cells showed evidence for an autocrine growth regulation by CSF-1. DNA ploidy and proliferation kinetic studies suggested that L428KSA were derived from the actively proliferating mononuclear Hodgkin's cell population of the parental cell line. Since the simultaneous expression of CSF-1 and c-fms is a characteristic feature of mononuclear phagocytes, these results suggest that Hodgkin's cells are affiliated with the monocyte/macrophage lineage or, at least, derived from a hemopoietic cell type with the capability for aberrant expression of a monocyte-specific growth factor and its receptor.

v-raf confers CSF-1 independent growth to a macrophage cell line and leads to immediate early gene expression without MAP-kinase activation.

The BAC-1.2F5 macrophage cell line depends on CSF-1 for proliferation and survival. Phosphorylation and activation of the RAF-1 kinase are among the early events in CSF-1 signal transduction. To characterize the role of RAF-1 in CSF-1-induced proliferation, we overexpressed oncogenically activated RAF-1, cellular RAF-1 and RAF-1 kinase-defective mutant proteins in BAC-1.2F5 cells. We were unable to establish stable cell lines expressing either kinase-negative or full length RAF-1 proteins, implying that expression of these molecules is not tolerated in BAC-1.2F5 cells. Oncogenically activated RAF-1 induces CSF-1-independent growth in the absence of autocrine growth factor production. Autonomous growth is not associated with dedifferentiation, since v-raf-expressing macrophages perform the same immunological functions as control cells. Intriguingly, autonomous growth correlates with the suppression of CSF-1-mediated MAP-Kinase activation and with the low constitutive expression of a number of CSF-1-inducible genes, including fos, jun, ets2, and myc, but also the genes for the inflammatory cytokines TNF alpha and IL-1 beta. Many of these genes have AP-1 binding sites in their promoters, and the v-raf-expressing cells contain constitutive AP-1 binding activity. These data indicate that RAF-1, but not MAP-Kinase, is a key component in CSF-1 mitogenic signal transduction, and are consistent with a working hypothesis in which RAF-1 mediates transcriptional activation of genes via AP-1.

The major SHP-1-binding, tyrosine-phosphorylated protein in macrophages is a member of the KIR/LIR family and an SHP-1 substrate.

The SH2 domain-containing cytoplasmic protein tyrosine phosphatase, SHP-1, negatively regulates hematopoietic cell signaling. SHP-1 is associated with a tyrosine phosphorylated, plasma membrane-spanning glycoprotein, pp130, in colony stimulating factor-1 stimulated or unstimulated macrophages. This association is phosphotyrosine dependent and is mediated by the amino-terminal SH2 domain of SHP-1. pp130 behaves as a substrate of SHP-1 in vitro and is hyperphosphorylated on tyrosine in SHP-1 deficient macrophages from viable-motheaten mice. Co-immunoprecipitation data indicate that pp130 is the product of the mouse p91/PIR-B gene that encodes a member of the killer cell inhibitory receptor (KIR)/leukocyte immunoglobulin-like receptor (LIR) family. By analogy to the KIRs, p91/PIR-B may represent a novel class of macrophage receptors which act to suppress macrophage activation. These observations identify SHP-1 interactions with and regulation of p91/PIR-B as a potential mechanism for inhibiting the signaling cascades linking extracellular stimuli to macrophage activation and/or development.

FMS (CSF-1 receptor) and CSF-1 transcripts and protein are expressed by human breast carcinomas in vivo and in vitro.

The expression in vivo of FMS transcripts and antigen by neoplastic epithelial cells was demonstrated immunohistochemically or by in situ hybridization in sixteen of seventeen human breast carcinoma specimens and one case of sclerosing adenosis. Expression of CSF-1 receptor (FMS) transcripts and protein was also observed in vitro in two or three breast carcinoma-derived cell lines and was dramatically increased by dexamethasone, a potent glucocorticoid and inducer of mammary epithelial cell differentiation. Immunohistochemical staining with an anti-CSF-1 antibody identified neoplastic epithelial cell co-expression of fms and CSF-1 antigens in more than one-third of the fms-positive invasive carcinoma specimens. These results suggest that autocrine and paracrine interactions of the lymphohematopoietic cytokine CSF-1 and its receptor may participate in the biology of human mammary neoplasms.

The role of colony-stimulating factor 1 and its receptor in the etiopathogenesis of endometrial adenocarcinoma.

Colony-stimulating factor 1 (CSF-1) is a homodimeric growth factor that humorally regulates the growth and differentiation of mononuclear phagocytes, and locally regulates maternal-fetal interactions during pregnancy. It exerts these actions through a transmembrane tyrosine kinase receptor, colony-stimulating factor 1 receptor (CSF-1R), the product of the c-fms proto-oncogene. Recent studies have demonstrated overexpression of CSF-1 and its receptor in breast, ovarian, and endometrial adenocarcinomas. To further investigate the possible role of CSF-1 and its receptor in the pathogenesis of endometrial adenocarcinoma, a prospective study was undertaken to study CSF-1 expression in benign and neoplastic endometrial epithelium and to compare serum CSF-1 levels in endometrial adenocarcinoma patients with healthy perimenopausal women. The mean serum levels of CSF-1 in 71 patients with endometrial cancer (4.9 +/- 1.8 microgram/liter) were significantly elevated compared with levels found in the 32 controls (3.5 +/- 1.1 microgram/liter). Within the endometrial adenocarcinoma group, circulating CSF-1 levels were significantly elevated in patients with large tumor volume, high grade, myometrial invasion, residual disease, and circulating CA-125 levels. High serum levels of serum CSF-1 were associated with elevated serum CA19-9 and CA-125 levels. Immunohistochemistry results revealed in tumor epithelium intense staining for CSF-1R (27 of 54 cases, 50%) and elevated staining for CSF-1 (41 of 54 cases, 75.9%), with intense staining of CSF-1 in 16 of 54 cases (29.6%). Staining was significantly greater in intensity and number of cells involved in malignant compared with benign epithelium for CSF-1R and CSF-1 (P = 0.05 and <0.0001, respectively). A positive correlation between amount and intensity of CSF-1 and CSF-1R staining in endometrial adenocarcinoma tissue was also demonstrated (P = 0.007). CSF-1 and CSF-1R mRNA was also detected in the tumor samples, confirming the expression of the protein in these tissues. Reverse transcription-PCR demonstrated the presence of mRNA for both the transmembrane and secreted forms of CSF-1 in all tumors analyzed. These results therefore support the hypotheses that CSF-1 and CSF-1R are overexpressed in endometrial adenocarcinoma, that levels of expression significantly correlate with clinicopathological risk factors for poor outcome, and that CSF-1 in association with its receptor via autocrine, juxtacrine, and/or paracrine interactions has a causal role in endometrial adenocarcinoma development and proliferation.