Tumor‐associated macrophages exhibit pro‐ and anti‐inflammatory properties by which they impact on pancreatic tumorigenesis

Pancreatic ductal adenocarcinoma (PDAC) still ranking 4th in the order of fatal tumor diseases is characterized by a profound tumor stroma with high numbers of tumor‐associated macrophages (TAMs). Driven by environmental factors, monocytes differentiate into M1‐ or M2‐macrophages, the latter commonly regarded as being protumorigenic. Because a detailed analysis of TAMs in human PDAC development is still lacking, freshly isolated PDAC‐derived TAMs were analyzed for their phenotype and impact on epithelial‐mesenchymal‐transition (EMT) of benign (H6c7) and malignant (Colo357) pancreatic ductal epithelial cells. TAMs exhibited characteristics of M1‐macrophages (expression of HLA‐DR, IL‐1β, or TNF‐α) and M2‐macrophages (expression of CD163 and IL‐10). In the presence of TAMs, H6c7, and Colo357 cells showed an elongated cell shape along with an increased expression of mesenchymal markers such as vimentin and reduced expression of epithelial E‐cadherin. Similar to TAMs, in vitro generated M1‐ and M2‐macrophages both mediated EMT in H6c7 and Colo357 cells. M1‐macrophages acquired M2‐characteristics during coculture that could be prevented by GM‐CSF treatment. However, M1‐macrophages still potently induced EMT in H6c7 and Colo357 cells although lacking M2‐characteristics. Overall, these data demonstrate that TAMs exhibit anti‐ as well as proinflammatory properties that equally contribute to EMT induction in PDAC initiation and development.     

Clinical significance of CD163+ tumor‐associated macrophages in patients with adult T‐cell leukemia/lymphoma

In several malignant tumors including lymphoma, macrophages that infiltrate tumor tissues are called tumor‐associated macrophages (TAMs). We discovered that TAMs, especially the CD163⁺ alternatively activated phenotype (M2), were closely involved with progression of adult T‐cell leukemia/lymphoma (ATLL). We used CD68 (a pan‐macrophage marker) and CD163 (an M2 marker) to immunostain 58 ATLL samples. Statistical analyses showed that a high number of CD68⁺ TAMs and an increased percentage of CD163⁺ cells among the TAMs were associated with a worse clinical prognosis; multivariate analysis indicated that the percentage of CD163⁺ cells was an independent prognostic factor. We also carried out in vitro coculture experiments with ATLL cell lines (ATN‐1 and TL‐Mor) and monocyte‐derived macrophages and found that direct coculture with M2 macrophages significantly increased BrdU incorporation into ATLL cell lines. A cytokine array analysis showed that macrophage‐derived soluble factors including C5a, tumor necrosis factor‐α, growth‐related oncogene‐α, CCL1/I‐309, and interleukin‐6 stimulated ATLL cell lines. CD163 expression in macrophages was strongly induced by direct contact with ATN‐1 cells, and downregulation of CD163 in macrophages significantly suppressed growth of cocultured ATN‐1 cells. These results suggest that interaction between M2 macrophages and lymphoma cells may be an appropriate target in treatment of patients with ATLL.     

Antitumor effect of nuclear factor‐κB decoy transfer by mannose‐modified bubble lipoplex into macrophages in mouse malignant ascites

Patients with malignant ascites (MAs) display several symptoms, such as dyspnea, nausea, pain, and abdominal tenderness, resulting in a significant reduction in their quality of life. Tumor‐associated macrophages (TAMs) play a crucial role in MA progression. Because TAMs have a tumor‐promoting M2 phenotype, conversion of the M2 phenotypic function of TAMs would be promising for MA treatment. Nuclear factor‐κB (NF‐κB) is a master regulator of macrophage polarization. Here, we developed targeted transfer of a NF‐κB decoy into TAMs by ultrasound (US)‐responsive, mannose‐modified liposome/NF‐κB decoy complexes (Man‐PEG bubble lipoplexes) in a mouse peritoneal dissemination model of Ehrlich ascites carcinoma. In addition, we investigated the effects of NF‐κB decoy transfection into TAMs on MA progression and mouse survival rates. Intraperitoneal injection of Man‐PEG bubble lipoplexes and US exposure transferred the NF‐κB decoy into TAMs effectively. When the NF‐κB decoy was delivered into TAMs by this method in the mouse peritoneal dissemination model, mRNA expression of the Th2 cytokine interleukin (IL)‐10 in TAMs was decreased significantly. In contrast, mRNA levels of Th1 cytokines (IL‐12, tumor necrosis factor‐α, and IL‐6) were increased significantly. Moreover, the expression level of vascular endothelial growth factor in ascites was suppressed significantly, and peritoneal angiogenesis showed a reduction. Furthermore, NF‐κB decoy transfer into TAMs significantly decreased the ascitic volume and number of Ehrlich ascites carcinoma cells in ascites, and prolonged mouse survival. In conclusion, we transferred a NF‐κB decoy efficiently by Man‐PEG bubble lipoplexes with US exposure into TAMs, which may be a novel approach for MA treatment.     

Modulatory effects of adiponectin on the polarization of tumor‐associated macrophages

The plasticity of macrophages with selective functional phenotypes partially arises in respective to their microenvironment. Tumor‐associated macrophages (TAMs) may promote disease progression with tumor specific manner. Here we report that in pediatric malignant soft‐tissue tumors, the presence of TAMs and expression of adiponectin (APN) are heterogeneous. Both APN and TAMs had high expression in rhabdomyosarcoma, especially in the malignant subtype, alveolar rhabdomyosarcoma. To investigate the mode of action of APN on TAM activation, a murine MN/MCA1 sarcoma model was used. The Results revealed that exogenous APN had no effect on MN/MCA1 proliferation but tumor size was markedly reduced in apn^?/? mice versus WT controls. The accumulation of TAMs in apn^?/? mice was also reduced which correlated to downregulated serum levels of MCP‐1. Likewise, TAMs in apn^?/? mice exhibited a M1‐like phenotype, characterized by increase in MHC II^high population and M1 phenotypic markers, such as iNOS gene and serum TNF‐α accompanied by a decrease in M2 markers, namely YM1 gene and serum IL‐10. In addition, APN deficiency increased the number of CD4⁺ T cells, CD8⁺ T cells and NK cells in tumors and reduced tumor metastasis. The altered phenotype of TAMs in apn^?/? mice was associated with a marked decrease in phospho‐p38 and treatment with a p38 MAPK inhibitor significantly reduced tumor size and increased MHC II expression on TAMs in WT mice, implying p38 MAPK signaling pathway may contribute to APN‐mediated TAM polarization. Collectively, our findings suggest that APN may have a potential role in regulating soft tissue sarcoma growth.     

CD163+ tumor-associated macrophage is a prognostic biomarker and is associated with therapeutic effect on malignant pleural effusion of lung cancer patients

CD163+ tumor-associated macrophages (TAMs) play an important role in the progression of cancer. However, the significance of CD163+ TAMs in malignant pleural effusion (MPE) is still unclear. The aim of this study is to evaluate the prognostic value of CD163+ TAMs in MPE, and the regulatory effect of an immune adjuvant (pseudomonas aeruginosa - mannose-sensitive hemagglutinin, PA-MSHA, which is used for MPE treatment in clinic) on CD163+ TAMs in MPE. Here, we found that the percentage of CD163+ TAMs in MPE was significantly higher than that in non-malignant pleural effusion (P<0.001). More importantly, CD163+ TAMs in MPE patients were an independent prognostic factor for progression-free survival. M2-related cytokines were highly expressed in MPE-derived CD163+ TAMs than in MPE-derived CD163− macrophages (P<0.05). CD163+ TAMs frequency in MPE patients was obviously reduced after PA-MSHA treatment in clinic (P<0.05). After treatment with PA-MSHA, M2 macrophages were re-educated to M1 macrophages in vitro. TLR4 blocking antibody inhibited M2 macrophages polarization to M1 macrophages induced by PA-MSHA. These findings highlight that accumulation of CD163+ TAMs in MPE caused by lung cancer is closely correlated with poor prognosis. CD163+ TAMs are associated with therapeutic effect in MPE. PA-MSHA re-educates CD163+ TAMs to M1 macrophages through TLR4-mediated pathway in MPE.     

Downregulation of 15‐hydroxyprostaglandin dehydrogenase by interleukin‐1β from activated macrophages leads to poor prognosis in pancreatic cancer

Chronic inflammation has a crucial role in cancer development and the progression of various tumors, including pancreatic ductal adenocarcinoma (PDAC). The arachidonate cascade is a major inflammatory pathway that produces several metabolites, such as prostaglandin E2. The enzyme 15‐hydroxyprostaglandin dehydrogenase (15‐PGDH) degrades prostaglandin and is frequently decreased in several types of cancer; however, the molecular mechanisms of 15‐PGDH suppression are unclear. The current study was carried out to elucidate the molecular mechanisms and clinical significance of 15‐PGDH suppression in PDAC. Here, we showed that interleukin‐1β (IL‐1β), a pro‐inflammatory cytokine, downregulates 15‐PGDH expression in PDAC cells, and that IL‐1β expression was inversely correlated with 15‐PGDH levels in frozen PDAC tissues. We also found that activated macrophages produced IL‐1β and reduced 15‐PGDH expression in PDAC cells. Furthermore, the number of CD163‐positive tumor‐associated macrophages was shown to be inversely correlated with 15‐PGDH levels in PDAC cells by immunohistochemical staining of 107 PDAC samples. Finally, we found that low 15‐PGDH expression was significantly associated with advanced tumors, presence of lymph node metastasis and nerve invasion, and poor prognosis in PDAC patients. Our results indicate that IL‐1β derived from TAMs suppresses 15‐PGDH expression in PDAC cells, resulting in poor prognosis of PDAC patients.     

Tumor‐associated macrophages secrete CC‐chemokine ligand 2 and induce tamoxifen resistance by activating PI3K/Akt/mTOR in breast cancer

Breast cancer is the most prevalent malignancy among women. Although endocrine therapy is effective, the development of endocrine resistance is a major clinical challenge. The tumor microenvironment (TME) promotes tumor malignancy, and tumor‐associated macrophages (TAM) within the TME play a crucial role in endocrine resistance. Herein, we aimed to elucidate the relationship between TAM and the endocrine‐resistant phenotype of breast cancer. Macrophages were cultured with conditioned medium (CM) from tamoxifen‐sensitive (MCF7‐S) or ‐resistant (MCF7‐R) MCF7 breast cancer cells. M2 polarization was detected by CD163 immunofluorescence. To determine the effect on endocrine resistance, MCF7 cells were cultured in the supernatant of different TAM, and then treated with tamoxifen. CC‐chemokine ligand 2 (CCL2) immunohistochemistry was carried out on pathological sections from 100 patients with invasive estrogen receptor‐positive breast cancer. We found that macrophages cultured in the CM of MCF7‐S and MCF7‐R cells were induced into TAM, with a more obvious M2 polarization in the latter. Tamoxifen resistance was increased by culture in TAM medium. TAM secreted CCL2, which increased endocrine resistance in breast cancer cells through activation of the PI3K/Akt/mTOR signaling pathway. High expression of CCL2 was correlated with infiltration of CD163+macrophages (r = 0.548, P < .001), and patients with high CCL2 expression presented shorter progression‐free survival than those with low CCL2 expression (P < .05). We conclude that CCL2 secreted by TAM activates PI3K/Akt/mTOR signaling and promotes an endocrine resistance feedback loop in the TME, suggesting that CCL2 and TAM may be novel therapeutic targets for patients with endocrine‐resistant breast cancer.     

Clinical significance of programmed cell death‐ligand 1 expression and the immune microenvironment at the invasive front of colorectal cancers with high microsatellite instability

Immunotherapy is reportedly effective in colorectal cancers (CRCs) with high microsatellite instability (MSI‐H); however, the specific cell types that respond to immune checkpoint therapy are unclear. Herein, we aimed to examine the expression of programmed cell death‐ligand 1 (PD‐L1) and related proteins in MSI‐H and microsatellite‐stable (MSS) CRCs to investigate the immune microenvironment at the tumor's invasive front. The MSI status was retrospectively assessed in 499 patients undergoing surgical resection of primary CRC; of these, 48 were classified as MSI‐H. Propensity score matching was performed, and tissues from 36 and 37 patients with MSI‐H and MSS CRCs, respectively, were immunohistochemically evaluated for PD‐L1, PD‐1, CD8 and CD68. PD‐L1 expression was evaluated separately for tumor cells (PD‐L1 [T]) and tumor‐infiltrating myeloid cells in the stroma (PD‐L1 [I]). PD‐L1 (T) was positive in only 5.4% and 36.1% of MSS and MSI‐H CRCs, while PD‐L1 (I) was positive in 27% and 72.2% of these CRCs, respectively. The PD‐L1 (T) and PD‐L1 (I) expression levels in MSI‐H CRCs significantly correlated with poor differentiation, lymphatic invasion and vascular invasion (p < 0.05), and with early‐stage adenocarcinoma and high budding grade (p < 0.05), respectively. Significantly more PD‐L1 (I), CD8‐positive cells and CD68‐positive macrophages were present at the invasive front than in the central tumor in MSI‐H CRCs (p < 0.005). PD‐L1 was expressed on both tumor cells and CD68/CD163‐positive (M2) macrophages at the invasive front of MSI‐H CRCs. In conclusion, PD‐L1‐positive tumor cells and M2‐type tumor‐associated macrophages may contribute to tumor invasion and immune escape at the invasive front.     

Tumor‐associated macrophage‐derived inflammatory cytokine enhances malignant potential of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an asbestos‐related aggressive malignant neoplasm. Due to the difficulty of achieving curative surgical resection in most patients with MPM, a combination chemotherapy of cisplatin and pemetrexed has been the only approved regimen proven to improve the prognosis of MPM. However, the median overall survival time is at most 12 mo even with this regimen. There has been therefore a pressing need to develop a novel chemotherapeutic strategy to bring about a better outcome for MPM. We found that expression of interleukin‐1 receptor (IL‐1R) was upregulated in MPM cells compared with normal mesothelial cells. We also investigated the biological significance of the interaction between pro‐inflammatory cytokine IL‐1β and the IL‐1R in MPM cells. Stimulation by IL‐1β promoted MPM cells to form spheroids along with upregulating a cancer stem cell marker CD26. We also identified tumor‐associated macrophages (TAMs) as the major source of IL‐1β in the MPM microenvironment. Both high mobility group box 1 derived from MPM cells and the asbestos‐activated inflammasome in TAMs induced the production of IL‐1β, which resulted in enhancement of the malignant potential of MPM. We further performed immunohistochemical analysis using clinical MPM samples obtained from patients who were treated with the combination of platinum plus pemetrexed, and found that the overexpression of IL‐1R tended to correlate with poor overall survival. In conclusion, the interaction between MPM cells and TAMs through a IL‐1β/IL‐1R signal could be a promising candidate as the target for novel treatment of MPM (Hyogo College of Medicine clinical trial registration number: 2973).     

High expression of interleukin‐11 is an independent indicator of poor prognosis in clear‐cell renal cell carcinoma

Interleukin‐11 (IL‐11), a member of the IL‐6 family of cytokines, exerts pleiotropic oncogenic activities by stimulating angiogenesis and metastasis in many cancer types. The present study aims to evaluate the impact of IL‐11 expression on recurrence and mortality of patients with clear‐cell renal cell carcinoma (ccRCC). We retrospectively enrolled 193 ccRCC patients undergoing nephrectomy at a single center. Clinicopathologic features, recurrence‐free survival (RFS) and overall survival (OS) were recorded. IL‐11 intensity was assessed by immunohistochemistry in tumor specimens. The Kaplan–Meier method was applied to compare survival curves. Cox regression models were used to analyze the impact of prognostic factors on RFS and OS. The concordance index (C‐index) was calculated to assess predictive accuracy. High IL‐11 expression is associated with increased risk of recurrence and poor survival for ccRCC patients (P < 0.001 and P < 0.001, respectively), especially those with early‐stage disease (TNM stage I + II). Multivariate analyses confirmed that IL‐11 expression was an independent prognostic factor for RFS and OS (P = 0.006 and P = 0.008, respectively). The predictive accuracy of well‐established prognostic models was improved when IL‐11 expression was integrated. In conclusion, high IL‐11 expression is an independent predictor of poor prognosis in ccRCC patients. It may help identify patients who could benefit from additional treatments and closer follow up.     

Impaired T cell function in malignant pleural effusion is caused by TGF‐β derived predominantly from macrophages

Malignant pleural effusion (MPE) is an indication of advanced cancer. Immune dysfunction often occurs in MPE. We aimed to identify the reason for impaired T cell activity in MPE from lung cancer patients and to provide clues toward potential immune therapies for MPE. The surface inhibitory molecules and cytotoxic activity of T cells in MPE and peripheral blood (PB) were analyzed using flow cytometry. Levels of inflammatory cytokines in MPE and PB were tested using ELISA. TGF‐β expression in tumor‐associated macrophages (TAMs) was also analyzed. The effect of TAMs on T cells was verified in vitro. Lastly, changes in T cells were evaluated following treatment with anti‐TGF‐β antibody. We found that expression levels of Tim‐3, PD‐1 and CTLA‐4 in T cells from MPE were upregulated compared with those from PB, but levels of IFN‐γ and Granzyme B were downregulated (p < 0.05). The amount of TGF‐β was significantly higher in MPE than in PB (p < 0.05). TGF‐β was mainly produced by TAMs in MPE. When T cells were co‐cultured with TAMs, expression levels of Tim‐3, PD‐1 and CTLA‐4 were significantly higher than controls, whereas levels of IFN‐γ and Granzyme B were significantly decreased, in a dose‐dependent manner (p < 0.05). In vitro treatment with anti‐TGF‐β antibody restored the impaired T cell cytotoxic activity in MPE. Our results indicate that macrophage‐derived TGF‐β plays an important role in impaired T cell cytotoxicity. It will therefore be valuable to develop therapeutic strategies against TGF‐β pathway for MPE therapy of lung cancer.     

Absolute monocyte count predicts overall survival in mantle cell lymphomas: correlation with tumour‐associated macrophages

Mantle cell lymphoma (MCL) is characterized by a variable clinical course in which patients can experience indolent disease or frequent relapses despite a good initial response to conventional therapy. Risk stratification of MCL is most frequently performed using the MCL International Prognostic Index (MIPI). Recent studies indicate that the peripheral blood absolute monocyte count (AMC) and tumour‐associated macrophages may reflect the state of the tumour microenvironment in lymphomas. The significance of AMC and tumour‐associated macrophages in the clinical course of MCL is unknown. The prognostic impact of the AMC, of CD68 expression and of CD163 expression was retrospectively examined in 103 MCL samples using the receiver operating characteristic curved. Patients with an AMC ≥ 375 cells/μL at diagnosis were more likely to present with advanced‐stage disease (p = 0.026), leukocytosis (p < 0.001), lymphocytosis (p = 0.01) and granulocytosis (p = 0.003). On univariate analysis, a high AMC (≥375 cells/μL) correlated with poorer overall survival (OS) (p = 0.01). Neither CD68 nor CD163 expression was significantly associated with either OS or event‐free survival. Multivariate analysis showed that a high AMC was a prognostic factor for OS, independent of the MIPI [hazards ratio (HR), 1.811; 95% confidence interval, 1.018–3.223; p = 0.043]. This study demonstrates that the AMC at the time of diagnosis is an independent prognostic factor for OS in MCL, which suggests the possibility that AMC may be used in addition to the MIPI to predict outcome in patients with MCL. Copyright © 2013 John Wiley & Sons, Ltd.     

Tumor associated macrophage expressing CD204 is associated with tumor aggressiveness of esophageal squamous cell carcinoma

Tumor associated macrophages (TAMs) are the most abundant cancer stromal cells educated by tumor microenvironment to acquire trophic functions facilitating angiogenesis, matrix breakdown and cancer cell motility. Tumor associated macrophages have anti‐inflammatory properties or “alternatively” activated (M2) phenotype expressing CD204 and/or CD163. To know the role of TAMs in the growth and progression of esophageal squamous cell carcinomas (ESCCs), we calculated intratumoral CD204, CD163 or CD68 expressing macrophage count (M?C) and CD34‐positive microvessel density (MVD) by immunohistochemistry in 70 cases of surgically resected ESCCs and compared them with the clinicopathological factors and prognosis of patients. M?C had positive linear association with MVD. High CD204⁺ M?C were significantly correlated with more malignant phenotypes including depth of tumor invasion, lymph and blood vessel invasion, lymph node metastasis as well as clinical stages. On the other hand, CD163⁺ M?C did not associate with these clinicopathological factors with the exception of depth of tumor invasion and blood vessel invasion. Patients with high CD204⁺ M?C ESCCs showed poor disease‐free survival (P = 0.021). Conditioned media of five ESCC cell lines (TE‐8, ‐9, ‐10, ‐11 and ‐15) induced mRNA as well as protein expression of CD204 but not of CD163 with upregulation of vascular endothelial growth factor‐A mRNA in TPA treated human acute monocytic leukemia cell line THP‐1. These results overall indicate that CD204 is a useful marker for TAMs contributing to the angiogenesis, progression and prognosis of ESCCs whose specific tumor microenvironment may educate macrophages to be CD204⁺ M2 TAMs.     

Colorectal cancer chemoprevention by 2 β‐cyclodextrin inclusion compounds of auraptene and 4′‐geranyloxyferulic acid

The inhibitory effects of novel prodrugs, inclusion complexes of 3‐(4′‐geranyloxy‐3′‐methoxyphenyl)‐2‐trans propenoic acid (GOFA) and auraptene (AUR) with β‐cyclodextrin (CD), on colon carcinogenesis were investigated using an azoxymethane (AOM)/dextran sodium sulfate (DSS) model. Male CD‐1 (ICR) mice initiated with a single intraperitoneal injection of AOM (10 mg/kg body weight) were promoted by the addition of 1.5% (w/v) DSS to their drinking water for 7 days. They were then given a basal diet containing 2 dose levels (100 and 500 ppm) of GOFA/β‐CD or AUR/β‐CD for 15 weeks. At Week 18, the development of colonic adenocarcinoma was significantly inhibited by feeding with GOFA/β‐CD at dose levels of 100 ppm (63% reduction in multiplicity, p < 0.05) and 500 ppm (83% reduction in the multiplicity, p < 0.001), when compared with the AOM/DSS group (multiplicity: 3.36 ± 3.34). In addition, feeding with 100 and 500 ppm (p < 0.01) of AUR/β‐CD suppressed the development of colonic adenocarcinomas. The dietary administration with GOFA/β‐CD and AUR/β‐CD inhibited colonic inflammation and also modulated proliferation, apoptosis and the expression of several proinflammatory cytokines, such as nuclear factor‐kappaB, tumor necrosis factor‐α, Stat3, NF‐E2‐related factor 2, interleukin (IL)‐6 and IL‐1β, which were induced in the adenocarcinomas. Our findings indicate that GOFA/β‐CD and AUR/β‐CD, especially GOFA/β‐CD, are therefore able to inhibit colitis‐related colon carcinogenesis by modulating inflammation, proliferation and the expression of proinflammatory cytokines in mice.     

Tumor-Associated Macrophages are Correlated with Tamoxifen Resistance in the Postmenopausal Breast Cancer Patients

Tumor-associated macrophages (TAMs) have been correlated with increased angiogenesis and poor prognosis in breast cancer. However, the precise role of TAMs in tamoxifen resistance remains unclear. We used immunohistochemical method to examine the expression of epidermal growth factor receptor (EGFR) and CD163+ macrophages in 100 breast cancer tissues. The clinical and biological features of 100 patients were estrogen receptor (ER)-positive and human epidermal growth factor receptor 2(Her-2)-negative tumors. The tamoxifen resistant tissues (n?=?48) were the surgical excision samples from patients who developed recurrence or metastasis at the time of adjuvant tamoxifen treatment. The tamoxifen resistant tissues were contrast to tamoxifen sensitive tissues (n?=?52). Positive staining for EGFR and CD163+ macrophages were observed in 21 samples (43.8 %) and in 26 samples (54.2 %) respectively in tamoxifen resistance group, which were higher than that of tamoxifen sensitive group (P?=?0.001 and P?=?0.000279 respectively). Significant positive correlations were found between the expression of EGFR and CD163+ macrophages (r?=?0.567, P?<?0.01). CD163+ macrophages were positively correlated with tumor size, lymph node metastasis and obesity. Obesity was also related to tamoxifen resistance (P?<?0.05). The patients with higher density of CD163+ macrophages infiltration suffered from shorter time to develop recurrence or metastasis (P?<?0.05). TAMs may be associated with tamoxifen resistance. Further studies are needed to investigate the potential mechanism between TAMs and tamoxifen resistance.     

Cross‐talk between ovarian cancer cells and macrophages through periostin promotes macrophage recruitment

Tumor‐associated macrophages (TAMs) contribute to tumor progression, but it is not clear how they are recruited to tumor sites. Here we showed that periostin (POSTN) was present at high levels in ovarian cancer ascetic fluids and was correlated with CD163⁺ TAMs. The high POSTN level and macrophage infiltration were inversely associated with relapse‐free survival for ovarian cancer patients. In vitro studies showed that coculture with macrophages significantly increased POSTN production in ovarian cancer cells. Further investigation found that POSTN production in ovarian cancer cells was promoted by transforming growth factor‐β generated by macrophages. Moreover, siRNA of POSTN and POSTN neutralizing antibody treatment showed that ovarian cancer cell‐derived POSTN promoted the recruitment of macrophages and modulated their cytokine secretion profile. Collectively, these data indicated that POSTN was an important factor for macrophage recruitment in the tumor microenvironment and is involved in the interactions between macrophages and ovarian cancer cells.     

M2‐like macrophage polarization in high lactic acid‐producing head and neck cancer

Reprogramming of glucose metabolism in tumor cells is referred to as the Warburg effect and results in increased lactic acid secretion into the tumor microenvironment. We have previously shown that lactic acid has important roles as a pro‐inflammatory and immunosuppressive mediator and promotes tumor progression. In this study, we examined the relationship between the lactic acid concentration and expression of LDHA and GLUT1, which are related to the Warburg effect, in human head and neck squamous cell carcinoma (HNSCC). Tumors expressing lower levels of LDHA and GLUT1 had a higher concentration of lactic acid than those with higher LDHA and GLUT1 expression. Lactic acid also suppressed the expression of LDHA and GLUT1 in vitro. We previously reported that lactic acid enhances expression of an M2 macrophage marker, ARG1, in murine macrophages. Therefore, we investigated the relationship between the lactic acid concentration and polarization of M2 macrophages in HNSCC by measuring the expression of M2 macrophage markers, CSF1R and CD163, normalized using a pan‐macrophage marker, CD68. Tumors with lower levels of CD68 showed a higher concentration of lactic acid, whereas those with higher levels of CSF1R showed a significantly higher concentration of lactic acid. A similar tendency was observed for CD163. These results suggest that tumor‐secreted lactic acid is linked to the reduction of macrophages in tumors and promotes induction of M2‐like macrophage polarization in human HNSCC.     

Upregulation of CD200 is associated with regulatory T cell expansion and disease progression in multiple myeloma

Immune dysfunction is an important feature of multiple myeloma (MM) leading to infections, enhancement of tumour growth and resistance to chemotherapy. The overexpression of CD200, expansion of T regulatory (Treg) cell and increased levels of immune modulatory cytokines like IL10, IL6 and transforming growth factor beta (TGFβ) were suggested to have a role in this context. The aim of this study was to assess CD200 expression, Treg percentage by flow cytometry and immune modulatory cytokines (IL10, IL6, TGFβ) by enzyme‐linked immunosorbent assay in MM patients at diagnosis. This study included 50 MM patients at diagnosis and 20 healthy controls. The positive CD200 expression was detected in 72% of MM patients. Among the CD200 positive group, 4/13 patients (30.8%) were classified as stage I, 18/23 (78.3%) were in stage II and 14/14 (100%) were in stage III; according to International scoring system. Treg percentage was significantly higher in stage III, followed by stage II then stage I (p < 0.01). Serum IL6, IL10 and TGFβ were significantly higher in MM patients as compared with controls (p < 0.01, p < 0.01, p < 0.05, respectively). The increased expression of CD200 and Treg percentages was associated with increased severity biomarkers (serum LDH and β2 microglobulin). The degree of CD200 expression was significantly positively correlated to Treg percentage (r = 0.565, p < 0.01). Analysis of the CD200 negative patients had a better progression free survival (p = 0.032) and overall survival (p = 0.04) as compared with those positive for CD200 expression. These findings illustrate a clear correlation between myeloma cell CD200 expression level and the frequency of immunosuppressive Treg cells. In conclusion, increased expression of CD200, expansion of suppressive Treg cells and elevation of cytokines might have a role in MM progression in this cohort of patients. Copyright © 2015 John Wiley & Sons, Ltd.