Hematopoietic colony-stimulating factors in head and neck cancers: Recent advances and therapeutic challenges

Colony-stimulating factors (CSFs) are key cytokines responsible for the production, maturation, and mobilization of the granulocytic and macrophage lineages from the bone marrow, which have been gaining attention for playing pro- and/or anti-tumorigenic roles in cancer. Head and neck cancers (HNCs) represent a group of heterogeneous neoplasms with high morbidity and mortality worldwide. Treatment for HNCs is still limited even with the advancements in cancer immunotherapy. Novel treatments for patients with recurrent and metastatic HNCs are urgently needed. This article provides an in-depth review of the role of hematopoietic cytokines such as granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), and interleukin-3 (IL-3; also known as multi-CSF) in the HNCs tumor microenvironment. We have reviewed current results from clinical trials using CSFs as adjuvant therapy to treat HNCs patients, and also clinical findings reported to date on the therapeutic application of CSFs toxicities arising from chemoradiotherapy.

Involvement of iNOS-induced reactive enteric glia cells in gastrointestinal motility disorders of postoperative Ileus mice

Postoperative ileus (POI) is the cessation or reduction of gastrointestinal (GI) motility after surgery. Reactive enteric glial cells (EGCs) are critical for maintaining bowel function. However, the triggering mechanisms and downstream effects of reactive EGCs in POI were poorly understood. The goal of this current study was to investigate whether the inducible nitric oxide synthase (iNOS)-driven reactive EGCs participated in GI motility disorders and mechanisms underlying altered GI motility in POI. Intestinal manipulation (IM)-induced POI mice and iNOS-/- mice were used in the study. Longitudinal muscle and myenteric plexuses (LMMPs) from the distal small intestine were stained by immunofluorescence. Our results found that the GI motility disorders occurred in the IM-induced POI mice, and reactive EGCs were observed in LMMPs. Glial metabolic inhibitor gliotoxin fluorocitrate (FC) treatment or iNOS gene knockout attenuated GI motility dysfunction. In addition, we also found that FC treatment or iNOS gene knockout significantly inhibited the fluorescence intensity macrophage colony-stimulating factor (M-CSF), which reduced M2 phenotype macrophages activation in LMMPs of IM-induced POI mice. Our findings demonstrated that iNOS-driven reactive EGCs played a key role and were tightly linked to the MMs homeostasis in the POI mice. EGCs are emerging as a new frontier in neurogastroenterology and a potential therapeutic target.

Change of monocytes/macrophages in ulcerative colitis patients with symptoms of anxiety and depression

BACKGROUND AND AIMS

Monocytes/macrophages play important roles in inflammatory bowel disease and depression, but few studies had focused on the change of monocytes/macrophages in ulcerative colitis (UC) patients with psychiatric disorders.

METHODS

UC patients were divided into two groups based on the Hospital Anxiety and Depression Scale (HADS). Demographic and clinical data were captured. Peripheral blood samples and intestinal biopsies were collected for the analysis of monocyte immunophenotype, phagocytic function, and CD4 + T cell differentiation. Transmission electron microscopy was used to observe the ultrastructure of intestinal macrophages.

RESULTS

A total of 139 UC patients were included. 37.41% and 32.37% of UC patients had symptoms of anxiety and depression. In patients with symptoms of anxiety/depression, mayo score, platelet count, erythrocyte sedimentation rate, and endoscopic score, histological scores were significantly higher than those in UC patients without. In patients with symptoms of anxiety/depression, the percentages of CD14 + + CD16 + monocytes and CD14 + CD16++ monocytes were higher, and the phagocytosis was decreased. Patients with symptoms of anxiety/depression had more CD68 + cells and higher M1/M2 ratios in the intestine mucosal layer compared to those without.

CONCLUSIONS

Monocytes and intestinal macrophages from UC patients with anxiety/depression tended to polarize to pro-inflammatory subtypes, and their function was also impaired.

Olive polyphenols attenuate TNF-α-stimulated M-CSF and IL-6 synthesis in osteoblasts: Suppression of Akt and p44/p42 MAP kinase signaling pathways

BACKGROUND

Olive oil polyphenols, which possess cytoprotective activities like anti-oxidant and anti-inflammatory effects, could modulate osteoblast functions. The aim of this study is to elucidate the effects and the underlying mechanisms of hydroxytyrosol and oleuropein on the tumor necrosis factor-α (TNF-α)-induced macrophage colony-stimulating factor (M-CSF) and interleukin-6 (IL-6) synthesis in osteoblasts.

METHODS

Osteoblast-like MC3T3-E1 cells were pretreated with hydroxytyrosol, oleuropein, deguelin, PD98059 or wedelolactone, and then stimulated by TNF-α. The levels of M-CSF and IL-6 in the conditioned medium were determined with ELISA. The mRNA expression levels of M-CSF or IL-6 were determined with real-time RT-PCR. The phosphorylation levels of Akt, p44/p42 mitogen-activated protein (MAP) kinase or NF-κB in the cell lysates were determined with Western blot analysis.

RESULTS

Hydroxytyrosol and oleuropein attenuated the TNF-α-stimulated M-CSF release. Deguelin, an inhibitor of Akt, significantly suppressed the TNF-α-stimulated M-CSF release, which failed to be affected by the MEK1/2 inhibitor PD98059 or the IκB inhibitor wedelolactone. Hydroxytyrosol and oleuropein suppressed the TNF-α-induced phosphorylation of Akt and p44/p42 MAP kinase. Hydroxytyrosol and oleuropein attenuated the TNF-α-stimulated IL-6 release. Hydroxytyrosol suppressed the TNF-α-induced mRNA expressions of M-CSF and IL-6. Hydroxytyrosol or oleuropein failed to affect the cell viability.

CONCLUSION

Our present findings strongly suggest that olive oil polyphenols hydroxytyrosol and oleuropein down-regulates TNF-α signaling at the points upstream of Akt and p44/p42 MAP kinase in osteoblasts, leading to the attenuation of M-CSF and IL-6 synthesis.

M-CSF Receptor Antagonists Inhibit the Initiation and Progression of Hepatocellular Carcinoma in Mice

BACKGROUND/AIM

The aim of this study was to investigate the effects of the macrophage colony-stimulating factor (M-CSF) receptor antagonist on hepatic carcinogenesis in mice.

MATERIALS AND METHODS

Mice were injected with diethylnitrosamine (DEN) and treated with M-CSF receptor antagonist GW2580 (GW) or a saline vehicle just after (early treated group) or 2 weeks after (late treated group) DEN injection. Animals were sacrificed after 28 weeks and incidence of tumor was assessed. Isolated Kupffer cells were co-cultured with M-CSF in the presence or absence of GW, and the concentration of VEGF was measured.

RESULTS

The incidence of tumors was significantly blunted both in the early- and the late-treated groups. In addition, angiogenesis within the tumor was also suppressed in both groups. The concentration of VEGF increased in Kupffer cells treated with M-CSF compared to those cultured without M-CSF. This increase was blunted by GW.

CONCLUSION

M-CSF and its receptor could be novel molecular targets for hepatocellular carcinoma.

Macrophage colony-stimulating factor (M-CSF) is an intermediate in the process of luteinizing hormone-induced decrease in natriuretic peptide receptor 2 (NPR2) and resumption of oocyte meiosis

Background

Luteinizing hormone (LH) regulation of the ligand, natriuretic peptide precursor type C, and its receptor, natriuretic peptide receptor 2 (NPR2), is critical for oocyte maturation; however, the mechanism is not fully understood. Macrophage colony-stimulating factor (M-CSF) has recently been shown to be involved in oocyte maturation and ovulation. In the present study we determined whether or not M-CSF plays a role in the intermediate signal that mediates LH regulation of NPR2 in resumption of oocyte meiosis.

Methods

Immature female C57BL/6 mice were injected i.p. with 5 IU of equine chorionic gonadotropin (eCG) to stimulate follicle development. After 44–48 h, the eCG-stimulated mice were injected i.p. with an ovulatory dose of 5 IU of human chorionic gonadotropin (hCG). The ovaries were excised at selected times. Pre-ovulatory follicles (POFs) and cumulus-oocyte complexes were cultured in different media. Immunohistochemical and quantitative real-time PCR analyses were used to assess the expression of M-CSF, M-CSF receptor (M-CSF-R), and NPR2. The presence of germinal vesicle breakdown (GVBD) was examined under a stereomicroscope to morphologically evaluate resumption of oocyte meiosis.

Results

NPR2 was mainly expressed in cumulus cells of pre-ovulatory follicles, while M-CSF and M-CSF-R were expressed in both mural granulosa and cumulus cells. The levels of M-CSF/M-CSF-R and NPR2 decreased within 4 h after treatment of hCG. M-CSF not only reduced the expression of NPR2 mRNA via its receptor (M-CSF-R), but also increased the proportion of GVBD in oocytes.

Conclusion

M-CSF serves as an intermediate signal, thus inducing a vital decrease in the NPR2 levels in cumulus cells, and regulates the process of LH-induced resumption of meiosis.

New Insight into Atherosclerosis in Hemodialysis Patients: Overexpression of Scavenger Receptor and Macrophage Colony-Stimulating Factor Genes

BACKGROUND

Scavenger receptors (SRs) play a pivotal role in atherogenesis. The mechanism of atherosclerosis, which is specific to hemodialysis (HD) patients, was studied on the basis of SR gene expressions.

METHODS

The gene expressions of SR type A (SR-A) and CD36 were studied in peripheral monocytes by real-time reverse transcription polymerase chain reaction. Data were compared between HD (n = 30) and age-matched control subjects (n = 10). Serum levels of macrophage colony-stimulating factor (M-CSF) were measured with enzyme-linked immunosorbent assay to test its role in SR expression. The statistical differences and associations between two continuous variables were assessed using the Mann-Whitney U test and Pearson's correlation coefficient, respectively.

RESULTS

The relative quantities of SR mRNAs were significantly greater in HD patients than in controls [median (interquartile range): SR-A, 1.67 (0.96-2.76) vs. 0.90 (0.60-1.04), p = 0.0060; CD36, 1.09 (0.88-1.74) vs. 0.74 (0.64-0.99), p = 0.0255]. The serum concentration of M-CSF was significantly higher in HD patients than in controls [1, 121 (999-1,342) vs. 176 (155-202) pg/ml, p < 0.0001]. In addition, the relative quantity of M-CSF mRNA was significantly greater in HD patients than in controls [0.79 (0.42-1.53) vs. 0.42 (0.28-0.66), p = 0.0392]. The serum M-CSF levels were positively correlated with both the relative quantity of SR-A mRNA (r² = 0.1681, p = 0.0086) and that of CD36 mRNA (r² = 0.1202, p = 0.0284) in all subjects (n = 40).

CONCLUSION

HD patients are predisposed to atherosclerosis as a consequence of their enhanced monocyte SR expressions. SRs and M-CSF are potential therapeutic targets for atherosclerosis in this high-risk population.

Doxorubicin resistance mediated by cytoplasmic macrophage colony-stimulating factor is associated with switch from apoptosis to autophagic cell death in MCF-7 breast cancer cells

Macrophage colony-stimulating factor is a vital factor in maintaining the biological function of monocyte-macrophage lineage. It is expressed in many tumor tissues and cancer cells. Recent findings indicate that macrophage colony-stimulating factor might contribute to chemoresistance, but the precise mechanisms are unclear. This study was to explore the effect of macrophage colony-stimulating factor on doxorubicin resistance in MCF-7 breast cancer cells and the possible mechanism. In the study, the human breast cancer cells, MCF-7, were transfected with macrophage colony-stimulating factor. We document that cytoplasmic macrophage colony-stimulating factor induces doxorubicin resistance and inhibits apoptosis in MCF-7 cells. Further studies demonstrated that cytoplasmic macrophage colony-stimulating factor-mediated apoptosis inhibition was dependent on the activation of PI3K/Akt/Survivin pathway. More importantly, we found that macrophage colony-stimulating factor-induced autophagic cell death in doxorubicin-treated MCF-7 cells. Taken together, we show for the first time that macrophage colony-stimulating factor-induced doxorubicin resistance is associated with the changes in cell death response with defective apoptosis and promotion of autophagic cell death.

Signaling Pathways in Osteoclast Differentiation

Osteoclasts are multinucleated cells of hematopoietic origin that are responsible for the degradation of old bone matrix. Osteoclast differentiation and activity are controlled by two essential cytokines, macrophage colony-stimulating factor (M-CSF) and the receptor activator of nuclear factor-κB ligand (RANKL). M-CSF and RANKL bind to their respective receptors c-Fms and RANK to stimulate osteoclast differentiation through regulation of delicate signaling systems. Here, we summarize the critical or essential signaling pathways for osteoclast differentiation including M-CSF-c-Fms signaling, RANKL-RANK signaling, and costimulatory signaling for RANK.

Effect of recombinant human bone morphogenetic protein-2 on bisphosphonate-treated osteoblasts

Objectives

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a side effect of bisphophonate therapy that has been reported in recent years. Osteoclastic inactivity by bisphosphonate is the known cause of BRONJ. Bone morphogenetic protein-2 (BMP-2) plays an important role in the development of bone. Recombinant human BMP-2 (rhBMP-2) is potentially useful as an activation factor for bone repair. We hypothesized that rhBMP-2 would enhance the osteoclast-osteoblast interaction related to bone remodeling.

Materials and Methods

Human fetal osteoblast cells (hFOB 1.19) were treated with 100 µM alendronate, and 100 ng/mL rhBMP-2 was added. Cells were incubated for a further 48 hours, and cell viability was measured using an MTT assay. Expression of the three cytokines from osteoblasts, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF), were analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay.

Results

Cell viability was decreased to 82.75%±1.00% by alendronate and then increased to 110.43%±1.35% after treatment with rhBMP-2 (P<0.05, respectively). OPG, RANKL, and M-CSF expression were all decreased by alendronate treatment. RANKL and M-CSF expression were increased, but OPG was not significantly affected by rhBMP-2.

Conclusion

rhBMP2 does not affect OPG gene expression in hFOB, but it may increase RANKL and M-CSF gene expression.

Enhancement of kinase selectivity in a potent class of arylamide FMS inhibitors

Structure-activity relationship (SAR) studies on a highly potent series of arylamide FMS inhibitors were carried out with the aim of improving FMS kinase selectivity, particularly over KIT. Potent compound 17r (FMS IC50 0.7 nM, FMS cell IC50 6.1 nM) was discovered that had good PK properties and a greater than fivefold improvement in selectivity for FMS over KIT kinase in a cellular assay relative to the previously reported clinical candidate 4. This improved selectivity was manifested in vivo by no observed decrease in circulating reticulocytes, a measure of bone safety, at the highest studied dose. Compound 17r was highly active in a mouse pharmacodynamic model and demonstrated disease-modifying effects in a dose-dependent manner in a strep cell wall-induced arthritis model of rheumatoid arthritis in rats.

Cryopreservation induces macrophage colony stimulating factor from human periodontal ligament cells in vitro

Cryopreservation is used to protect vital periodontal ligaments during the transplantation of teeth. We investigated which gene products implicated in root resorption are upregulated in human periodontal ligament cells by cryopreservation, and whether cryopreservation affects the expression of macrophage-colony stimulating factor (M-CSF) in human periodontal ligament cells. We used customized microarrays to compare gene expression in human periodontal ligament cells cultured from teeth immediately after extraction and from cryopreserved teeth. Based on the result of these assays, we examined M-CSF expression in periodontal ligament cells from the immediately extracted tooth and cryopreserved teeth by real-time PCR, enzyme-linked immunosorbent assay (ELISA), Western blot analysis, and immunofluorescence. We also investigated whether human bone marrow cells differentiate into tartrate-resistant acid phosphatase (TRAP) positive osteoclasts when stimulated with RANKL (Receptor Activator for Nuclear Factor κ B Ligand) together with any secreted M-CSF present in the supernatants of the periodontal ligament cells cultured from the various groups of teeth. M-CSF was twofold higher in the periodontal ligament cells from the rapid freezing teeth than in those from the immediately extracted group (p < 0.05). Cryopreservation increased M-CSF expression in the periodontal ligament cells when analyzed by real time PCR, ELISA, Western blotting, and immunofluorescence (p < 0.05). TRAP positive osteoclasts were formed in response to RANKL and the secreted M-CSF present in the supernatants of all the experimental groups except negative control. These results demonstrate that cryopreservation promotes the production of M-CSF, which plays an important role in root resorption by periodontal ligament cells.