Elevated CSF1 serum concentration predicts poor overall survival in women with early breast cancer

Role of CSF1R 550th-tryptophan in kusunokinin and CSF1R inhibitor binding and ligand-induced structural effect

Binding affinity is an important factor in drug design to improve drug-target selectivity and specificity. In this study, in silico techniques based on molecular docking followed by molecular dynamics (MD) simulations were utilized to identify the key residue(s) for CSF1R binding affinity among 14 pan-tyrosine kinase inhibitors and 15 CSF1R-specific inhibitors. We found tryptophan at position 550 (W550) on the CSF1R binding site interacted with the inhibitors' aromatic ring in a π-π way that made the ligands better at binding. Upon W550-Alanine substitution (W550A), the binding affinity of trans-(-)-kusunokinin and imatinib to CSF1R was significantly decreased. However, in terms of structural features, W550 did not significantly affect overall CSF1R structure, but provided destabilizing effect upon mutation. The W550A also did not either cause ligand to change its binding site or conformational changes due to ligand binding. As a result of our findings, the π-π interaction with W550's aromatic ring could be still the choice for increasing binding affinity to CSF1R. Nevertheless, our study showed that the increasing binding to W550 of the design ligand may not ensure CSF1R specificity and inhibition since W550-ligand bound state did not induce significantly conformational change into inactive state.

MYC regulates CSF1 expression via microRNA 17/20a to modulate tumor-associated macrophages in osteosarcoma

Osteosarcoma (OS) is the most common primary bone tumor of childhood. Approximately 20%-30% of OSs carry amplification of chromosome 8q24, which harbors the oncogene c-MYC and correlates with a poor prognosis. To understand the mechanisms that underlie the ability of MYC to alter both the tumor and its surrounding tumor microenvironment (TME), we generated and molecularly characterized an osteoblast-specific Cre-Lox-Stop-Lox-c-MycT58A p53fl/+ knockin genetically engineered mouse model (GEMM). Phenotypically, the Myc-knockin GEMM had rapid tumor development with a high incidence of metastasis. MYC-dependent gene signatures in our murine model demonstrated significant homology to the human hyperactivated MYC OS. We established that hyperactivation of MYC led to an immune-depleted TME in OS demonstrated by the reduced number of leukocytes, particularly macrophages. MYC hyperactivation led to the downregulation of macrophage colony-stimulating factor 1, through increased microRNA 17/20a expression, causing a reduction of macrophage population in the TME of OS. Furthermore, we developed cell lines from the GEMM tumors, including a degradation tag-MYC model system, which validated our MYC-dependent findings both in vitro and in vivo. Our studies utilized innovative and clinically relevant models to identify a potentially novel molecular mechanism through which MYC regulates the profile and function of the OS immune landscape.

The Role of Tumor Epithelial-Mesenchymal Transition and Macrophage Crosstalk in Cancer Progression

PURPOSE OF REVIEW

The purpose of this review is to summarize the recently published findings regarding the role of epithelial to mesenchymal transition (EMT) in tumor progression, macrophages in the tumor microenvironment, and crosstalk that exists between tumor cells and macrophages.

RECENT FINDINGS

EMT is a crucial process in tumor progression. In association with EMT changes, macrophage infiltration of tumors occurs frequently. A large body of evidence demonstrates that various mechanisms of crosstalk exist between macrophages and tumor cells that have undergone EMT resulting in a vicious cycle that promotes tumor invasion and metastasis. Tumor-associated macrophages and tumor cells undergoing EMT provide reciprocal crosstalk which leads to tumor progression. These interactions provide potential targets to exploit for therapy.

Serum immuno-oncology markers carry independent prognostic information in patients with newly diagnosed metastatic breast cancer, from a prospective observational study

BACKGROUND

Metastatic breast cancer (MBC) is a challenging disease, and despite new therapies, prognosis is still poor for a majority of patients. There is a clinical need for improved prognostication where immuno-oncology markers can provide important information. The aim of this study was to evaluate serum immuno-oncology markers in MBC patients and their respective relevance for prediction of survival.

PATIENTS AND METHODS

We investigated a broad panel of 92 immuno-oncology proteins in serum from 136 MBC patients included in a prospective observational study (NCT01322893) with long-term follow-up. Serum samples were collected before start of systemic therapy and analyzed using multiplex proximity extension assay (Olink Target 96 Immuno-Oncology panel). Multiple machine learning techniques were used to identify serum markers with highest importance for prediction of overall and progression-free survival (OS and PFS), and associations to survival were further evaluated using Cox regression analyses. False discovery rate was then used to adjust for multiple comparisons.

RESULTS

Using random forest and random survival forest analyses, we identified the top nine and ten variables of highest predictive importance for OS and PFS, respectively. Cox regression analyses revealed significant associations (P < 0.005) of higher serum levels of IL-8, IL-10 and CAIX with worse OS in multivariable analyses, adjusted for established clinical prognostic factors including circulating tumor cells (CTCs). Similarly, high serum levels of IL-8, IL-10, ADA and CASP8 significantly associated with worse PFS. Interestingly, high serum levels of FasL significantly associated with improved OS and PFS. In addition, CSF-1, IL-6, MUC16, TFNSFR4 and CD244 showed suggestive evidence (P < 0.05) for an association to survival in multivariable analyses. After correction for multiple comparisons, IL-8 still showed strong evidence for correlation to survival.

CONCLUSION

To conclude, we found six serum immuno-oncology markers that were significantly associated with OS and/or PFS in MBC patients, independently of other established prognostic factors including CTCs. Furthermore, an additional five serum immuno-oncology markers provided suggestive evidence for an independent association to survival. These findings highlight the relevance of immuno-oncology serum markers in MBC patients and support their usefulness for improved prognostication. Trial registration Clinical Trials (NCT01322893), registered March 25, 2011.

Breast tumor metastasis following filgrastim administration due to the SDF-1/CXCR4 pathway

Filgrastim, a recombinant type of granulocyte-colony stimulating factor (G-CSF), has a high potential to manage chemotherapy-induced leukopenia. It can increase stromal cell-derived factor 1 (SDF-1) which may stimulate C-X-C chemokine receptor type 4 (CXCR4) to migrate bone marrow-derived stem/progenitor cells to the bloodstream. Here, we aimed to investigate in vitro and in vivo effects of filgrastim on cell migration, invasion, and metastasis. A lentivirus vector of the anti-CXCR4 receptor was first used for the CXCR4 knockout. Effects of filgrastim on cell proliferation and migration were then investigated on 4T1 cells by Transwell migration and wound healing assay. At last, the effects of filgrastim on cell metastasis and the possible involved mechanisms have been investigated in a metastatic murine breast tumor. The knockout of the CXCR4 receptor could lead to a decrease in cell proliferation, migration, and invasion of the 4T1 cells. Filgrastim could directly target SDF-1 and upregulate the expression of the CXCR4 receptor. The knockout of the CXCR4 receptor reduced cell metastasis in an animal model of breast cancer. CXCR4 receptor stimulation by the filgrastim-affected pathways is a conserved evolutionary response that could increase cancer cell proliferation and consequent cell metastasis. Our results suggest that the activation of the CXCR4 receptor is a conserved evolutionary response that can increase cell proliferation, migration, and consequent metastasis. It seems that filgrastim may increase the chance of cancer cell metastasis in people continuously receiving it to increase the number of neutrophils. Filgrastim induces the SDF-1/CXCR4 axis on tumor cell growth. SDF-1 and its receptor CXCR4 are vital targets for filgrastim. The CXCR4 can stimulate the PI3K/AKT, NF-κB, and JAK/STAT signaling pathways. The SDF-1/CXCR4 pathway promotes cell chemotaxis and proliferation via MAPKs signaling. It also enhances cell survival, proliferation, and angiogenesis, increasing tumor cell metastasis. The STAT3-mediated inflammation is essential for tumorigenesis processes, and Akt, Wnt, STAT3, and CXCR4 signaling pathways are all correlated. CXCR4 = C-X-C chemokine receptor type 4, SDF-1 = stromal-derived-factor-1, MAPK = mitogen activated protein kinase; NF-κB = nuclear factor-κB, PI3K = phosphoinositide 3-kinase, JAK = Janus kinase, STAT = signal transducer and activator of transcription, PLC = phospholipase C, PKC = Protein kinase C, GRK = G protein-coupled receptor kinase.

Potential Stereoselective Binding of Trans-(±)-Kusunokinin and Cis-(±)-Kusunokinin Isomers to CSF1R

Breast cancer cell proliferation and migration are inhibited by naturally extracted trans-(−)-kusunokinin. However, three additional enantiomers of kusunokinin have yet to be investigated: trans-(+)-kusunokinin, cis-(−)-isomer and cis-(+)-isomer. According to the results of molecular docking studies of kusunokinin isomers on 60 breast cancer-related proteins, trans-(−)-kusunokinin was the most preferable and active component of the trans-racemic mixture. Trans-(−)-kusunokinin targeted proteins involved in cell growth and proliferation, whereas the cis-(+)-isomer targeted proteins involved in metastasis. Trans-(−)-kusunokinin targeted CSF1R specifically, whereas trans-(+)-kusunokinin and both cis-isomers may have bound AKR1B1. Interestingly, the compound’s stereoisomeric effect may influence protein selectivity. CSF1R preferred trans-(−)-kusunokinin over trans-(+)-kusunokinin because the binding pocket required a ligand planar arrangement to form a π-π interaction with a selective Trp550. Because of its large binding pocket, EGFR exhibited no stereoselectivity. MD simulation revealed that trans-(−)-kusunokinin, trans-(+)-kusunokinin and pexidartinib bound CSF1R differently. Pexidartinib had the highest binding affinity, followed by trans-(−)-kusunokinin and trans-(+)-kusunokinin, respectively. The trans-(−)-kusunokinin-CSF1R complex was found to be stable, whereas trans-(+)-kusunokinin was not. Trans-(±)-kusunokinin, a potential racemic compound, could be developed as a selective CSF1R inhibitor when combined.

Tumor-associated macrophages: Potential target of natural compounds for management of breast cancer

A large body of experimental research reveals that tumor-associated macrophages (TAMs) are the major immunosuppressor cells in the breast tumor microenvironment (TME). The infiltration of macrophages is correlated with inverse outcomes like disease-free survival and overall survival of cancer patients. They are responsible for heterogeneity, metastasis, and drug resistance. Further, their density in tumor beds is correlated with stage and therapy response. The current review is aimed at summarizing mechanisms and signaling pathways that modulate immune-suppressive phenotype and expansion of TAMs. The review presents an overview of the interdependence of tumor cells and TAMs in TME to promote metastasis, drug resistance and immune suppressive phenotype. This review also presents the potential natural compounds that modulate the immune-suppressive functions of TAMs and their signaling pathways. Finally, this review provides nanotechnology approaches for the targeted delivery of natural products. This review shed light on BC management including clinical studies on the prognostic relevance of TAMs and natural compounds that sensitizes BC.

Discovery of (Z)-1-(3-((1H-Pyrrol-2-yl)methylene)-2-oxoindolin-6-yl)-3-(isoxazol-3-yl)urea Derivatives as Novel and Orally Highly Effective CSF-1R Inhibitors for Potential Colorectal Cancer Immunotherapy

Inhibiting the polarization or survival of tumor-associated macrophages through blocking CSF-1/CSF-1R signal transduction has become a promising strategy for cancer immunotherapy. Herein, a series of (Z)-1-(3-((1H-pyrrol-2-yl)methylene)-2-oxoindolin-6-yl)-3-(isoxazol-3-yl)urea derivatives were designed, synthesized, and evaluated as novel and orally highly effective CSF-1R inhibitors for colorectal cancer immunotherapy. Among these derivatives, compound 21 was found to possess excellent CSF-1R inhibitory activity (IC₅₀ = 2.1 nM) and potent antiproliferative activity against colorectal cancer cells. Compound 21 inhibited the progression of colorectal cancer by suppressing the migration of macrophages, reprograming M2-like macrophages to the M1 phenotype, and enhancing the antitumor immunity. More importantly, compound 21, as a single agent, showed significantly superior in vivo anticolorectal cancer efficacy over PLX3397, highlighting a promising candidate for the immunotherapy of colorectal cancer.

Cross Talk Between Macrophages and Cancer Cells in the Bone Metastatic Environment

The skeleton is a common site for cancer metastases with the bone microenvironment providing the appropriate conditions for cancer cell colonization. Once in bone, cancer cells effectively manipulate their microenvironment to support their growth and survival. Despite previous efforts to improve treatment modalities, skeletal metastases remain with poor prognoses. This warrants an improved understanding of the mechanisms leading to bone metastasis that will aid development of effective treatments. Macrophages in the tumor microenvironment are termed tumor associated macrophages (TAMs) and their crosstalk with cancer cells is critical in regulating tumorigenicity in multiple cancers. In bone metastases, this crosstalk is also being increasingly implicated but the specific signaling pathways remain incompletely understood. Here, we summarize the reported functions, interactions, and signaling of macrophages with cancer cells during the metastatic cascade to bone. Specifically, we review and discuss how these specific interactions impact macrophages and their profiles to promote tumor development. We also discuss the potential of targeting this crosstalk to inhibit disease progression. Finally, we identify the remaining knowledge gaps that will need to be addressed in order to fully consider therapeutic targeting to improve clinical outcomes in cancer patients.

Reversing an Oncogenic Epithelial-to-Mesenchymal Transition Program in Breast Cancer Reveals Actionable Immune Suppressive Pathways

Approval of checkpoint inhibitors for treatment of metastatic triple negative breast cancer (mTNBC) has opened the door for the use of immunotherapies against this disease. However, not all patients with mTNBC respond to current immunotherapy approaches such as checkpoint inhibitors. Recent evidence demonstrates that TNBC metastases are more immune suppressed than primary tumors, suggesting that combination or additional immunotherapy strategies may be required to activate an anti-tumor immune attack at metastatic sites. To identify other immune suppressive mechanisms utilized by mTNBC, our group and others manipulated oncogenic epithelial-to-mesenchymal transition (EMT) programs in TNBC models to reveal differences between this breast cancer subtype and its more epithelial counterpart. This review will discuss how EMT modulation revealed several mechanisms, including tumor cell metabolism, cytokine milieu and secretion of additional immune modulators, by which mTNBC cells may suppress both the innate and adaptive anti-tumor immune responses. Many of these pathways/proteins are under preclinical or clinical investigation as therapeutic targets in mTNBC and other advanced cancers to enhance their response to chemotherapy and/or checkpoint inhibitors.

Tumor-associated myeloid cells provide critical support for T-ALL

Despite harboring mutations in oncogenes and tumor suppressors that promote cancer growth, T-cell acute lymphoblastic leukemia (T-ALL) cells require exogenous cells or signals to survive in culture. We previously reported that myeloid cells, particularly dendritic cells, from the thymic tumor microenvironment support the survival and proliferation of primary mouse T-ALL cells in vitro. Thus, we hypothesized that tumor-associated myeloid cells would support T-ALL in vivo. Consistent with this possibility, in vivo depletion of myeloid cells results in a significant reduction in leukemia burden in multiple organs in 2 distinct mouse models of T-ALL and prolongs survival. The impact of the myeloid compartment on T-ALL growth is not dependent on suppression of antitumor T-cell responses. Instead, myeloid cells provide signals that directly support T-ALL cells. Transcriptional profiling, functional assays, and acute in vivo myeloid-depletion experiments identify activation of IGF1R as a critical component of myeloid-mediated T-ALL growth and survival. We identify several myeloid subsets that have the capacity to directly support survival of T-ALL cells. Consistent with mouse models, myeloid cells derived from human peripheral blood monocytes activate IGF1R and directly support survival of primary patient T-ALL cells in vitro. Furthermore, enriched macrophage gene signatures in published clinical samples correlate with inferior outcomes for pediatric T-ALL patients. Collectively, these data reveal that tumor-associated myeloid cells provide signals critical for T-ALL growth in multiple organs in vivo and implicate tumor-associated myeloid cells and associated signals as potential therapeutic targets.

A Pan-cancer Analysis Reveals the Abnormal Expression and Drug Sensitivity of CSF1

BACKGROUND

Colony-stimulating factor-1 (CSF1) is a cytokine that is closely related to normal organ growth and development as well as tumor progression.

OBJECTIVE

We aimed to summarize and clarify the reasons for the abnormal expression of CSF1 in tumors and explore the role of CSF1 in tumor progression. Furthermore, drug response analysis may provide a reference for clinical medication.

METHODS

The expression of CSF1 was analyzed by TCGA and CCLE. Besides, cBioPortal and MethSurv databases were used to conduct mutation and DNA methylation analyses. Further, correlations between CSF1 expression and tumor stage, survival, immune infiltration, drug sensitivity and enrichment analyses were validated via UALCAN, Kaplan-Meier plotter, TIMER, CTRP and Coexperia databases.

RESULTS

CSF1 is expressed in a variety of tissues, meaningfully, it can be detected in blood. Compared with normal tissues, CSF1 expression was significantly decreased in most tumors. The missense mutation and DNA methylation of CSF1 may cause the downregulated expression. Moreover, decreased CSF1 expression was related with higher tumor stage and worse survival. Further, the promoter DNA methylation level of CSF1 was prognostically significant in most tumors. Besides, CSF1 was closely related to immune infiltration, especially macrophages. Importantly, CSF1 expression was associated with a good response to VEGFRs inhibitors, which may be due to the possible involvement of CSF1 in tumor angiogenesis and metastasis processes.

CONCLUSION

The abnormal expression of CSF1 could serve as a promising biomarker of tumor progression and prognosis in pan-cancer. Significantly, angiogenesis and metastasis inhibitors may show a good response to CSF1-related tumors.

Redefining macrophage and neutrophil biology in the metastatic cascade

Tumor cells metastasize to distant organs through a complex series of events that are driven by tumor intrinsic and extrinsic factors. In particular, non-malignant stromal cells, including immune cells, modify tumor metastatic behavior. Of these cells, tumor-associated innate immune cells, particularly macrophages and neutrophils, suppress the cytotoxic activity of innate and adaptive killer cells and interact with tumor cells to promote their growth and malignancy. These findings in mouse cancer models suggest that targeting these sub-populations of immune cells holds therapeutic promise in treating metastatic disease. In this review, we describe the origin and role of the macrophages, neutrophils, and their progenitors in the metastatic cascade and suggest strategies that might enhance cancer therapy.

CD163+ tumor-associated macrophage accumulation in breast cancer patients reflects both local differentiation signals and systemic skewing of monocytes

Objectives

The accumulation of tumor‐associated macrophages (TAMs) is correlated with poor clinical outcome, but the mechanisms governing their differentiation from circulating monocytes remain unclear in humans.

Methods

Using multicolor flow cytometry, we evaluated TAMs phenotype in 93 breast cancer (BC) patients. Furthermore, monocytes from healthy donors were cultured in the presence of supernatants from dilacerated primary tumors to investigate their differentiation into macrophages (MΦ) in vitro. Additionally, we used transcriptomic analysis to evaluate BC patients’ blood monocytes profiles.

Results

We observed that high intra‐tumor CD163‐expressing TAM density is predictive of reduced survival in BC patients. In vitro, M‐CSF, TGF‐β and VEGF from primary tumor supernatants skewed the differentiation of healthy donor blood monocytes towards CD163^highCD86^lowIL‐10^high M2‐like MΦ that strongly suppressed CD4⁺ T‐cell expansion via PD‐L1 and IL‐10. In addition, blood monocytes from about 40% of BC patients displayed an altered response to in vitro stimulation, being refractory to type‐1 MΦ (M1‐MΦ) differentiation and secreting higher amounts of immunosuppressive, metastatic‐related and angiogenic cytokines. Aside from showing that monocyte transcriptome is significantly altered by the presence of BC, we also demonstrated an overall metabolic de‐activation in refractory monocytes of BC patients. In contrast, monocytes from sensitive BC patients undergoing normal M1‐MΦ differentiation showed up‐regulation of IFN‐response genes and had no signs of metabolic alteration.

Conclusion

Altogether, our results suggest that systemic factors skew BC patient blood monocytes towards a pro‐metastatic profile, resulting in the accumulation of further polarised CD163^high TAMs resembling type‐2 MΦ (M2‐MΦ) in the local BC microenvironment. These data indicate that monitoring circulating monocytes in BC patients may provide an indication of early systemic alterations induced by cancer and, thus, be instrumental in the development of improved personalised immunotherapeutic interventions.

Reverting Immune Suppression to Enhance Cancer Immunotherapy

Tumors employ strategies to escape immune control. The principle aim of most cancer immunotherapies is to restore effective immune surveillance. Among the different processes regulating immune escape, tumor microenvironment-associated soluble factors, and/or cell surface-bound molecules are mostly responsible for dysfunctional activity of tumor-specific CD8⁺T cells. These dynamic immunosuppressive networks prevent tumor rejection at several levels, limiting also the success of immunotherapies. Nevertheless, the recent clinical development of immune checkpoint inhibitors or of molecules modulating cellular targets and immunosuppressive enzymes highlights the great potential of approaches based on the selective disruption of immunosuppressive networks. Currently, the administration of different categories of immunotherapy in combination regimens is the ultimate modality for impacting the survival of cancer patients. With the advent of immune checkpoint inhibitors, designed to mount an effective antitumor immune response, profound changes occurred in cancer immunotherapy: from a global stimulation of the immune system to a specific targeting of an immune component. This review will specifically highlight the players, the mechanisms limiting an efficient antitumor response and the current immunotherapy modalities tailored to target immune suppressive pathways. We also discuss the ongoing challenges encountered by these strategies and provide suggestions for circumventing hurdles to new immunotherapeutic approaches, including the use of relevant biomarkers in the optimization of immunotherapy regimens and the identification of patients who can benefit from defined immune-based approaches.

Low infiltration of tumor-associated macrophages in high c-Myb-expressing breast tumors

Tumor-associated macrophages (TAMs) are prominent components of tumor stroma that promotes tumorigenesis. Many soluble factors participate in the deleterious cross-talk between TAMs and transformed cells; however mechanisms how tumors orchestrate their production remain relatively unexplored. c-Myb is a transcription factor recently described as a negative regulator of a specific immune signature involved in breast cancer (BC) metastasis. Here we studied whether c-Myb expression is associated with an increased presence of TAMs in human breast tumors. Tumors with high frequency of c-Myb-positive cells have lower density of CD68-positive macrophages. The negative association is reflected by inverse correlation between MYB and CD68/CD163 markers at the mRNA levels in evaluated cohorts of BC patients from public databases, which was found also within the molecular subtypes. In addition, we identified potential MYB-regulated TAMs recruiting factors that in combination with MYB and CD163 provided a valuable clinical multigene predictor for BC relapse. We propose that identified transcription program running in tumor cells with high MYB expression and preventing macrophage accumulation may open new venues towards TAMs targeting and BC therapy.

Beyond PD-1/PD-L1 Inhibition: What the Future Holds for Breast Cancer Immunotherapy

Cancer immunotherapy has altered the management of human malignancies, improving outcomes in an expanding list of diseases. Breast cancer - presumably due to its perceived low immunogenicity - is a late addition to this list. Furthermore, most of the focus has been on the triple negative subtype because of its higher tumor mutational load and lymphocyte-enriched stroma, although emerging data show promise on the other breast cancer subtypes as well. To this point the clinical use of immunotherapy is limited to the inhibition of two immune checkpoints, Programmed Cell Death Protein 1 (PD-1) and Cytotoxic T-lymphocyte-associated Protein 4 (CTLA-4). Consistent with the complexity of the regulation of the tumor - host interactions and their lack of reliance on a single regulatory pathway, combinatory approaches have shown improved efficacy albeit at the cost of increased toxicity. Beyond those two checkpoints though, a large number of co-stimulatory or co-inhibitory molecules play major roles on tumor evasion from immunosurveillance. These molecules likely represent future targets of immunotherapy provided that the promise shown in early data is translated into improved patient survival in randomized trials. The biological role, prognostic and predictive implications regarding breast cancer and early clinical efforts on exploiting these immune-related therapeutic targets are herein reviewed.

Plasma levels of M-CSF and VEGF in laboratory diagnostics and differentiation of selected histological types of cervical cancers

Background

The search of useful serum biomarkers for the early detection of cervical cancers has been of a high priority. The activation of Macrophage-Colony Stimulating Factor (M-CSF) and Vascular Endothelial Growth Factor (VEGF) is likely involved in the pathogenesis and spread of cancer. We compared the plasma levels of M-CSF and VEGF to the ones of commonly accepted tumor markers CA 125and SCC-Ag in three groups of patients: 1. the cervical cancer group (patients with either squamous cell carcinoma or adenocarcinoma); 2. the cervical dysplasia group; 3. the control group.

Methods

This cohort study included 100 patients with cervical cancer and 55 patients with cervical dysplasia. The control group consisted of 50 healthy volunteers. The plasma levels of VEGF and M-CSF were determined using ELISA, while CA 125 and SCC-Ag concentrations were obtained by the chemiluminescent microparticle immunoassay (CMIA).

Results

The median levels of M-CSF and VEGF as well as CA 125 and SCC-Ag in the entire group of cervical cancer patients, were significantly different compared to the healthy women group. In case of both the squamous cell carcinoma and the adenocarcinoma groups, plasma levels of M-CSF and VEGF were higher compared to the control group. No significant differences in the studied parameters between the squamous cell carcinoma and the adenocarcinoma group were observed. The highest sensitivity and specificity were obtained for VEGF (81.18 and 76.00%, respectively) and SCC-Ag (81.18%; 74.00%) in the squamous cell carcinoma group and for VEGF (86.67%; 76.00%) in the adenocarcinoma group. The area under the ROC curve for VEGF was the largest in the adenocarcinoma group followed by the squamous cell carcinoma group (0.9082 and 0.8566 respectively).

Conclusions

Obtained results indicate a possible clinical applicability and a high diagnostic power for the combination of MSC-F, VEGF, CA 125 and SCC-Ag in the diagnosis of both studied types of cervical cancer.

Diagnostic Power of Cytokine M-CSF, Metalloproteinase 2 (MMP-2) and Tissue Inhibitor-2 (TIMP-2) in Cervical Cancer Patients Based on ROC Analysis

Macrophage colony-stimulating factor (M-CSF), matrix metalloproteinase-2 (MMP-2) and its specific tissue inhibitor (TIMP-2) may play an important role in the pathogenesis of cancer disease. We investigated the plasma levels and diagnostic power (ROC curve analysis) of M-CSF, MMP-2, TIMP-2 and tumor markers CA 125 and SCC-Ag in cervical cancer (CC) patients as compared to control group. The study included 89 patients with cervical cancer. The control group consisted of 50 healthy, untreated women. The plasma levels of M-CSF, MMP-2 and TIMP-2 were determined using ELISA, CA 125 and SCC-Ag – by CMIA method. The median levels of M-CSF, TIMP-2, SCC-Ag and CA 125 in the entire group of CC were significantly different than compared to the healthy women group. MMP-2 showed the highest value of sensitivity from all examined parameters (in stage I of CC – 93.10%, II – 82.76%, III and IV – 96.88%, total group – 92.05%). The highest specificity was obtained by M-CSF (86%). The area under the ROC curve (AUC) of M-CSF (0.8051) was the largest of all the tested parameters (even higher than commonly used tumor markers) in the group of cervical cancer. The combination of M-CSF, MMP-2 or TIMP-2 with SCC antigen resulted in an increase AUCs in all cases (0.8760;0.7880;0.8081;respectively). The findings of this study suggest the usefulness of all examined parameters in the diagnostics of CC patients. Out of the tested substances, M-CSF also appears to be the best candidate for cancer diagnostics in all stages of the disease, based on ROC analysis.

Identification of an Unfavorable Immune Signature in Advanced Lung Tumors from Nrf2-Deficient Mice

AIMS

Activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway in normal cells inhibits carcinogenesis, whereas constitutive activation of Nrf2 in cancer cells promotes tumor growth and chemoresistance. However, the effects of Nrf2 activation in immune cells during lung carcinogenesis are poorly defined and could either promote or inhibit cancer growth. Our studies were designed to evaluate tumor burden and identify immune cell populations in the lungs of Nrf2 knockout (KO) versus wild-type (WT) mice challenged with vinyl carbamate.

RESULTS

Nrf2 KO mice developed lung tumors earlier than the WT mice and exhibited more and larger tumors over time, even at late stages. T cell populations were lower in the lungs of Nrf2 KO mice, whereas tumor-promoting macrophages and myeloid-derived suppressor cells were elevated in the lungs and spleen, respectively, of Nrf2 KO mice relative to WT mice. Moreover, 34 immune response genes were significantly upregulated in tumors from Nrf2 KO mice, especially a series of cytokines (Cxcl1, Csf1, Ccl9, Cxcl12, etc.) and major histocompatibility complex antigens that promote tumor growth.

INNOVATION

Our studies discovered a novel immune signature, characterized by the infiltration of tumor-promoting immune cells, elevated cytokines, and increased expression of immune response genes in the lungs and tumors of Nrf2 KO mice. A complementary profile was also found in lung cancer patients, supporting the clinical significance of our findings.

CONCLUSION

Overall, our results confirmed a protective role for Nrf2 in late-stage carcinogenesis and, unexpectedly, suggest that activation of Nrf2 in immune cells may be advantageous for preventing or treating lung cancer. Antioxid. Redox Signal.

Plasma levels and diagnostic utility of macrophage-colony stimulating factor, matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 as tumor markers in cervical cancer patients

Macrophage-colony stimulating factor, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1 may play an important role in malignant processes. The aim of this study was to investigate the diagnostic power of those parameters (serological biomarkers) in comparison to cancer antigen 125 and squamous cell carcinoma antigen in cervical cancer patients and in relation to the control groups. The study included 100 cervical cancer patients, 50 patients with cervical ectropion and 50 healthy women. Plasma levels of tested parameters were determined by enzyme-linked immunosorbent assay, cancer antigen 125, and squamous cell carcinoma antigen by chemiluminescent microparticle immunoassay. Plasma levels of all parameters in the total cancer group showed statistical significance (in all cases p < 0.05). In stage I of cancer only medial supraclavicular fossa and tissue inhibitor of metalloproteinase-1, in stage II all the tested parameters and cancer antigen 125, and in stage III + IV macrophage-colony stimulating factor, matrix metalloproteinase-9, and cancer antigen 125 showed statistical significance when compared to the healthy volunteers group. Macrophage-colony stimulating factor showed the highest value of sensitivity from all tested parameters (I: 56.25%, II: 72.73%, III + IV: 77.14% and 69% in total cervical cancer group). The highest specificity was obtained by matrix metalloproteinase-9 (94%). Positive predictive values were highest also for matrix metalloproteinase-9 (I: 82.35%, II: 84.21%, III + IV: 88% and 94.55% in total cervical cancer group), negative predictive values for macrophage-colony stimulating factor (I: 75.44%, II: 82.69%, III + IV: 87.5% and 58.11% in total cervical cancer group) and tumor markers. In the total cervical cancer group, all tested parameters showed statistically significant areas under receiver operating characteristic curve, but maximum range was obtained for the combination macrophage-colony stimulating factor + squamous cell carcinoma antigen (0.8723). The combined analysis of tested parameters and tumor markers resulted in an increase in sensitivity and areas under receiver operating characteristic curve values, which provides hope for developing new panel of biomarkers that may be used in the diagnosis of cervical cancer in the future.

Colony-stimulating factor-1 and colony-stimulating factor-1 receptor co-expression is associated with disease progression in gastric cancer

Colony‑stimulating‑factor‑1 (CSF‑1) is a hematopoietic growth factor that exerts its effects through the c‑fms/CSF‑1 receptor (CSF‑1R). The CSF‑1/CSF‑1R axis is thought to be involved in the development of several types of cancer. This study aimed to clarify the clinical and biological significance of the CSF‑1/CSF‑1R axis in gastric cancer (GC). For this purpose, we evaluated CSF‑1 and CSF‑1R expression in GC tissues from 148 patients by RT‑qPCR and immunohistochemistry. The biological roles of the CSF‑1/CSF‑1R axis were investigated by measuring the cell proliferation and migration, and anoikis resistance in a human GC cell line following treatment with recombinant human CSF‑1 and/or CSF‑1R inhibitor. The results revealed that an elevated expression of CSF‑1 or CSF‑1R significantly correlated with disease progression and with a poor overall survival (OS, P=0.037 and 0.016, respectively) and disease‑free survival (DFS, P<0.001 and <0.001, respectively) of patients with GC. Furthermore, a high co‑expression of CSF‑1 and CSF‑1R was an independent prognostic factor for OS (HR, 1.38; 95% CI, 1.02‑1.88; P=0.038) and DFS (HR, 1.79; 95% CI, 1.21‑2.67; P=0.004), and an independent risk factor for lymph node and peritoneal metastasis. Immunohistochemical analysis revealed an intense CSF‑1/CSF‑1R expression in the cytoplasm of cancer cells in primary GC tissues. CSF‑1 or CSF‑1R expression positively correlated with vascular endothelial growth factor A (VEGFA) or Fms related tyrosine kinase 1 (FLT1) expression in GC tissues. Treatment with recombinant human CSF‑1 promoted proliferation, migration and anoikis resistance in a GC cell line. These effects were generally blocked by CSF‑1R inhibition. On the whole, the findings of this study indicate that the CSF‑1/CSF‑1R axis may be a clinically useful prognostic and predictive biomarker for lymph node and peritoneal metastasis and a potential therapeutic target in GC.

Colony stimulating factor 1 receptor blockade improves the efficacy of chemotherapy against human neuroblastoma in the absence of T lymphocytes

Tumor-associated macrophages can promote growth of cancers. In neuroblastoma, tumor-associated macrophages have greater frequency in metastatic versus loco-regional tumors, and higher expression of genes associated with macrophages helps to predict poor prognosis in the 60% of high-risk patients who have MYCN-non-amplified disease. The contribution of cytotoxic T-lymphocytes to anti-neuroblastoma immune responses may be limited by low MHC class I expression and low exonic mutation frequency. Therefore, we modelled human neuroblastoma in T-cell deficient mice to examine whether depletion of monocytes/macrophages from the neuroblastoma microenvironment by blockade of CSF-1R can improve the response to chemotherapy. In vitro, CSF-1 was released by neuroblastoma cells, and topotecan increased this release. In vivo, neuroblastomas formed by subcutaneous co-injection of human neuroblastoma cells and human monocytes into immunodeficient NOD/SCID mice had fewer human CD14⁺ and CD163⁺ cells and mouse F4/80⁺ cells after CSF-1R blockade. In subcutaneous or intra-renal models in immunodeficient NSG or NOD/SCID mice, CSF-1R blockade alone did not affect tumor growth or mouse survival. However, when combined with cyclophosphamide plus topotecan, the CSF-1R inhibitor BLZ945, either without or with anti-human and anti-mouse CSF-1 mAbs, inhibited neuroblastoma growth and synergistically improved mouse survival. These findings indicate that depletion of tumor-associated macrophages from neuroblastomas can be associated with increased chemotherapeutic efficacy without requiring a contribution from T-lymphocytes, suggesting the possibility that combination of CSF-1R blockade with chemotherapy might be effective in patients who have limited anti-tumor T-cell responses.

Differential prognostic impact of interleukin-34 mRNA expression and infiltrating immune cell composition in intrinsic breast cancer subtypes

Interleukin-34 (IL-34) is a ligand for the CSF-1R and has also two additional receptors, PTPRZ1 and syndecan-1. IL-34 plays a role in innate immunity, inflammation, and cancer. However, the role of IL-34 in breast cancer is still ill-defined. We analyzed IL-34 mRNA expression in breast cancer cell lines and breast cancer patients and applied established computational approaches (CIBERSORT, ESTIMATE, TIMER, TCIA), to analyze gene expression data from The Cancer Genome Atlas (TCGA). Expression of IL-34 was associated with a favorable prognosis in luminal and HER2 but not basal breast cancer patients. Gene expression of CSF-1 and CSF-1R was strongly associated with myeloid cell infiltration, while we found no or only weak correlations between IL-34, PTPRZ1, syndecan-1 and myeloid cells. In vitro experiments showed that tyrosine phosphorylation of CSF-1R, ERK, and FAK and cell migration are differentially regulated by IL-34 and CSF-1 in breast cancer cell lines. Collectively, our data suggest that correlation of IL-34 gene expression with survival is dependent on the molecular breast cancer subtype. Furthermore, IL-34 is not associated with myeloid cell infiltration and directly regulates breast cancer cell migration and signaling.

Colony stimulating factor-1 in saliva in relation to age, smoking, and oral and systemic diseases

Colony stimulating factor (CSF)-1 is a growth factor that stimulates the survival, proliferation and differentiation of mononuclear phagocytes, which has been implicated in several inflammatory diseases. This study evaluated the possible influence of age, sex, smoking, periodontitis, caries, and several systemic conditions on salivary levels of CSF-1. Four-hundred and forty-one individuals were enrolled in this study. All participants answered a health questionnaire and underwent a comprehensive oral examination. Stimulated saliva was collected and CSF-1 levels were analysed by enzyme-linked immunosorbent assay. Salivary levels of CSF-1 were significantly increased in participants over 64 years old and in non-smoking individuals, whereas no difference was observed between men and women. Individuals having periodontitis and manifest caries had significantly higher levels of CSF-1. Participants with muscle and joint disease exhibited increased CSF-1 levels as compared to those without. Age, smoking, percentage of pockets ≥4 mm, number of manifest caries lesions, and presence of tumor were associated with CSF-1 levels. Salivary levels of CSF-1 are associated with age, smoking, periodontitis, manifest caries, and the presence of muscle and joint diseases and tumors. CSF-1 might be a promising biomarker candidate in saliva of both local and systemic conditions that needs further investigation.

Diverse in vivo effects of soluble and membrane-bound M-CSF on tumor-associated macrophages in lymphoma xenograft model

Macrophage colony-stimulating factor (M-CSF) is an important cytokine for monocyte/macrophage lineage. Secretory M-CSF (sM-CSF) and membrane-bound M-CSF (mM-CSF) are two major alternative splicing isoforms. The functional diversity of these isoforms in the activation of tumor-associated macrophages (TAMs), especially in lymphoma microenvironment, has not been documented. Here, we studied the effects of M-CSF isoforms on TAMs in xenograft mouse model. More infiltrating TAMs were detected in microenvironment with mM-CSF and sM-CSF. TAMs could be divided into three subpopulations based on their expression of CD206 and Ly6C. While sM-CSF had greater potential to recruit and induce differentiation of TAMs and TAM subpopulations, mM-CSF had greater potential to induce proliferation of TAMs and TAM subpopulations. Though both isoforms educated TAMs and TAM subpopulations to M2-like macrophages, mM-CSF and sM-CSF induced different spectrums of phenotype-associated genes in TAMs and TAM subpopulations. These results suggested the diverse effects of M-CSF isoforms on the activation of TAMs and TAM subpopulations in lymphoma microenvironments.

Systematic analysis of mRNA expression profiles in NSCLC cell lines to screen metastasis-related genes

Lung cancer is the most prevalent cancer in humans and has the lowest survival outcomes due to its high metastatic potential. The aim of the present study was to screen for metastasis-related genes (MRGs) by investigating the differential expression genes (DEGs) identified by the mRNA expression profiles in SPC-A-1sci (highly metastatic) and SPC-A-1 (parental) cells. DEGs were screened using Genespring software. Gene Ontology and pathway enrichment analyses of these DEGs were performed. Interaction networks between the proteins encoded by the DEGs were identified using the database BioGRID and were visualized by Cytoscape. Modular analysis of the protein-protein interaction network was performed in CFinder. Among these DEGs, the expression levels of 18 genes were examined in SPC-A-1sci and SPC-A-1 cell lines with reverse transcription-quantitative polymerase chain reaction, and 10 of the 18 genes were assessed by western blotting to validate the results of the microarray. Furthermore, the role of metallothionein 1X (MT1X) in non-small cell lung cancer was explored in functional assays and 72 pairs of clinical samples in vitro. Finally, 4,838 DEGs were screened, including 798 upregulated and 4,040 downregulated genes. The significantly enriched functions included gene expression, cytosol and poly-(A) RNA binding, and the most enriched pathway was biosynthesis of antibiotics. Furthermore, MT1X was revealed to promote the migration and invasion ability in SPC-A-1sci and PC-9 lung cancer cell lines. Therefore, MT1X was identified as a candidate MRG through systematic analysis in the present microarray, which was demonstrated to offer potential reference value in screening MRGs.

The Basis of Oncoimmunology

Cancer heterogeneity, a hallmark enabling clonal survival and therapy resistance, is shaped by active immune responses. Antigen-specific T cells can control cancer, as revealed clinically by immunotherapeutics such as adoptive T-cell transfer and checkpoint blockade. The host immune system is thus a powerful tool that, if better harnessed, could significantly enhance the efficacy of cytotoxic therapy and improve outcomes for cancer sufferers. To realize this vision, however, a number of research frontiers must be tackled. These include developing strategies for neutralizing tumor-promoting inflammation, broadening T-cell repertoires (via vaccination), and elucidating the mechanisms by which immune cells organize tumor microenvironments to regulate T-cell activity. Such efforts will pave the way for identifying new targets for combination therapies that overcome resistance to current treatments and promote long-term cancer control.

Tumor-associated macrophages and anti-tumor therapies: complex links

Myeloid cells infiltrating the tumor microenvironment, especially tumor-associated macrophages (TAMs), are essential providers of cancer-related inflammation, a condition known to accelerate tumor progression and limit the response to anti-tumor therapies. As a matter of fact, TAMs may have a dual role while interfering with cancer treatments, as they can either promote or impair their functionality. Here we review the connection between macrophages and anticancer therapies; moreover, we provide an overview of the different strategies to target or re-program TAMs for therapeutic purposes.

Role of the colony-stimulating factor (CSF)/CSF-1 receptor axis in cancer

Cancer cells employ a variety of mechanisms to evade apoptosis and senescence. Pre-eminent among these is the aberrant co-expression of growth factors and their ligands, forming an autocrine growth loop that promotes tumour formation and progression. One growth loop whose transforming potential has been repeatedly demonstrated is the CSF-1/CSF-1R axis. Expression of CSF-1 and/or CSF-1R has been documented in a number of human malignancies, including breast, prostate and ovarian cancer and classical Hodgkin's lymphoma (cHL). This review summarizes the large body of work undertaken to study the role of this cytokine receptor system in malignant transformation. These studies have attributed a key role to the CSF-1/CSF-1R axis in supporting tumour cell survival, proliferation and enhanced motility. Moreover, increasing evidence implicates paracrine interactions between CSF-1 and its receptor in defining a tumour-permissive and immunosuppressive tumour-associated stroma. Against this background, we briefly consider the prospects for therapeutic targeting of this system in malignant disease.

Myeloid Cells as Targets for Therapy in Solid Tumors

It is well established that cancer development ensues based on reciprocal interactions between genomically altered neoplastic cells and diverse populations of recruited "host" cells co-opted to support malignant progression. Among the host cells recruited into tumor microenvironments, several subtypes of myeloid cells, including macrophages, monocytes, dendritic cells, and granulocytes contribute to tumor development by providing tumor-promoting factors as well as a spectrum of molecules that suppress cytotoxic activities of T lymphocytes. Based on compelling preclinical data revealing that inhibition of critical myeloid-based programs leads to tumor suppression, novel immune-based therapies and approaches are now entering the clinic for evaluation. This review discusses mechanisms underlying protumorigenic programming of myeloid cells and discusses how targeting of these has potential to attenuate solid tumor progression via the induction and of mobilization CD8 cytotoxic T cell immunity.

Control of CSF-1 induced inflammation in teleost fish by a soluble form of the CSF-1 receptor

The colony-stimulating factor-1 (CSF-1) is the principal regulator of the survival, proliferation, differentiation, and function of macrophages and their precursors, and has been shown to play a role in the etiology of inflammation. We recently identified a novel mechanism for the control of CSF-1 activity in teleost fish, through the production of an inhibitory soluble form of the CSF-1 receptor (sCSF-1R). Primary goldfish kidney macrophages selectively expressed sCSF-1R during the senescence phase, which corresponds to a defined stage of in vitro culture development where inhibition of macrophage proliferation and apoptotic cell death are prominent. In contrast, primary macrophage cultures undergoing active proliferation displayed low levels of sCSF-1R expression. Addition of purified recombinant sCSF-1R to developing primary macrophage cultures leads to a dose-dependent decrease in macrophage proliferation and inhibits macrophage antimicrobial functions including chemotaxis, phagocytosis, and production of reactive oxygen intermediates. Using a goldfish in vivo model of self-resolving peritonitis, we found that sCSF-1R plays a role in the inhibition of inflammation, following an initial acute phase of antimicrobial responses within an inflammatory site. Soluble CSF-1R inhibits pro-inflammatory cytokine production, inhibits leukocyte recruitment to the inflammatory site and decreases ROS production in a dose-dependent manner. This sCSF-1R-dependent regulation of inflammation appears to be an elegant mechanism for the control of macrophage numbers at inflammatory sites of lower vertebrates. Overall, our results provide new insights into the evolutionary origins of the CSF-1 immune regulatory axis.

Functional Relationship between Tumor-Associated Macrophages and Macrophage Colony-Stimulating Factor as Contributors to Cancer Progression

The current review article describes the functional relationship between tumor-associated macrophages (TAM) as key cellular contributors to cancer malignancy on the one hand and macrophage-colony-stimulating factor (M-CSF or CSF-1) as an important molecular contributor on the other. We recapitulate the available data on expression of M-CSF and the M-CSF receptor (M-CSFR) in human tumor tissue as constituents of a stromal macrophage signature and on the limits of the predictive and prognostic value of plasma M-CSF levels. After providing an update on current insights into the nature of TAM heterogeneity at the level of M1/M2 phenotype and TAM subsets, we give an overview of experimental evidence, based on genetic, antibody-mediated, and pharmacological disruption of M-CSF/M-CSFR signaling, for the extent to which M-CSFR signaling can not only determine the TAM quantity, but can also contribute to shaping the phenotype and heterogeneity of TAM and other related tumor-infiltrating myeloid cells (TIM). Finally, we review the accumulating information on the – sometimes conflicting – effects blocking M-CSFR signaling may have on various aspects of cancer progression such as tumor growth, invasion, angiogenesis, metastasis, and resistance to therapy and we thereby discuss in how far these different effects actually reflect a contribution of TAM.

Cytokine networks that mediate epithelial cell-macrophage crosstalk in the mammary gland: implications for development and cancer

Dynamic interactions between the hormone responsive mammary gland epithelium and surrounding stromal macrophage populations are critical for normal development and function of the mammary gland. Macrophages are versatile cells capable of diverse roles in mammary gland development and maintenance of homeostasis, and their function is highly dependent on signals within the local cytokine microenvironment. The mammary epithelium secretes a number of cytokines, including colony stimulating factor 1 (CSF1), transforming growth factor beta 1 (TGFB1), and chemokine ligand 2 (CCL2) that affect the abundance, phenotype and function of macrophages. However, aberrations in these interactions have been found to increase the risk of tumour formation, and utilisation of stromal macrophage support by tumours can increase the invasive and metastatic potential of the cancer. Studies utilising genetically modified mouse models have shed light on the significance of epithelial cell-macrophage crosstalk, and the cytokines that mediate this communication, in mammary gland development and tumourigenesis. This article reviews the current status of our understanding of the roles of epithelial cell-derived cytokines in mammary gland development and cancer, with a focus on the crosstalk between epithelial cells and the local macrophage population.

Hypoxia-inducible factor-dependent signaling between triple-negative breast cancer cells and mesenchymal stem cells promotes macrophage recruitment

Intratumoral hypoxia induces the recruitment of stromal cells, such as macrophages and mesenchymal stem cells (MSCs), which stimulate invasion and metastasis by breast cancer cells (BCCs). Production of macrophage colony-stimulating factor 1 (CSF1) by BCCs is required for macrophage recruitment, but the mechanisms underlying CSF1 expression have not been delineated. Triple-negative breast cancers have increased expression of genes regulated by hypoxia-inducible factors (HIFs). In this study, we delineate two feed-forward signaling loops between human MDA-MB-231 triple-negative BCCs and human MSCs that drive stromal cell recruitment to primary breast tumors. The first loop, in which BCCs secrete chemokine (C-X-C motif) ligand 16 (CXCL16) that binds to C-X-C chemokine receptor type 6 (CXCR6) on MSCs and MSCs secrete chemokine CXCL10 that binds to receptor CXCR3 on BCCs, drives recruitment of MSCs. The second loop, in which MSCs secrete chemokine (C-C motif) ligand 5 that binds to C-C chemokine receptor type 5 on BCCs and BCCs secrete cytokine CSF1 that binds to the CSF1 receptor on MSCs, drives recruitment of tumor-associated macrophages and myeloid-derived suppressor cells. These two signaling loops operate independent of each other, but both are dependent on the transcriptional activity of HIFs, with hypoxia serving as a pathophysiological signal that synergizes with chemokine signals from MSCs to trigger CSF1 gene transcription in triple-negative BCCs.

The promotion of breast cancer metastasis caused by inhibition of CSF-1R/CSF-1 signaling is blocked by targeting the G-CSF receptor

Treatment options are limited for patients with breast cancer presenting with metastatic disease. Targeting of tumor-associated macrophages through the inhibition of colony-stimulating factor-1 receptor (CSF-1R), a key macrophage signaling pathway, has been reported to reduce tumor growth and metastasis, and these treatments are now in clinical trials. Here, we report that, surprisingly, treatment with neutralizing anti-CSF-1R and anti-CSF-1 antibodies, or with two different small-molecule inhibitors of CSF-1R, could actually increase spontaneous metastasis without altering primary tumor growth in mice bearing two independently derived mammary tumors. The blockade of CSF-1R or CSF-1 led to increased levels of serum G-CSF, increased frequency of neutrophils in the primary tumor and in the metastasis-associated lung, as well as increased numbers of neutrophils and Ly6C(hi) monocytes in the peripheral blood. Neutralizing antibody against the G-CSF receptor, which regulates neutrophil development and function, reduced the enhanced metastasis and neutrophil numbers that resulted from CSF-1R blockade. These results indicate that the role of the CSF-1R/CSF-1 system in breast cancer is far more complex than originally proposed, and requires further investigation as a therapeutic target.

SWATH™- and iTRAQ-based quantitative proteomic analyses reveal an overexpression and biological relevance of CD109 in advanced NSCLC

To identify cancer-related proteins, we used isobaric tags in a relative and absolute quantitation (iTRAQ) proteomic approach and SWATH™ quantification approach to analyze the secretome of an isogenic pair of highly metastatic and low metastatic non-small-cell lung cancer (NSCLC) cell lines. In addition, we compared two groups of pooled serum samples (12 early-stage and 12 late-stage patients) to mine data for candidates screened by iTRAQ-labeled proteomic analysis. A total of 110 proteins and 71 proteins were observed to be significantly differentially expressed in the cell line secretome and NSCLC sera, respectively. Among these proteins, CD109 was found to be highly expressed in both the highly metastatic cell line secretome and the group of late-stage patients. A sandwich ELISA assay also demonstrated an elevation of serum CD109 levels in individual NSCLC patients (n=30) compared with healthy subjects (n=19). Furthermore, CD109 displayed higher expression in lung cancer tissues compared with their matched noncancerous lung tissues (n=72). In addition, the knockdown of CD109 influenced several NSCLC cell bio-functions, for instance, depressing cell growth, affecting cell cycle phases. These phenomena suggest that CD109 plays a critical role in NSCLC progression.

BIOLOGICAL SIGNIFICANCE

We simultaneously applied two quantitative proteomic approaches-iTRAQ-labeling and SWATH™-to analyze the secretome of metastatic cell lines, in order to explore the cancer-associated proteins in conditioned media. In this study, our results indicate that CD109 plays a critical role in non-small-cell lung cancer (NSCLC) progression, and is overexpressed in advanced NSCLC.