Pathophysiology of Tumor‐Associated Macrophages

β-Klotho inhibits CSF-1 secretion and delays the development of endometrial cancer

Senescent cells can drive tumors development by promoting chronic inflammation. There is a significant correlation between β-Klotho expression profiles and endometrial cancer (EC). However, how β-Klotho regulates the occurrence and development of uterine EC remains to be further studied. Our research found that compared with normal endometrial tissues, β-Klotho expression levels in EC tissues were significantly reduced; overexpression of β-Klotho significantly inhibited aging, proliferation and migration but promoted apoptosis of EC cells cultured in vitro. In normal endometrial cells, results confirmed that reduced levels of β-Klotho promoted CSF-1 secretion, and the migration ability of macrophages was significantly enhanced when co-cultured with normal endometrial cells. In contrast, the expression of CSF-1 was significantly reduced after overexpression of β-Klotho in EC cells, and the macrophage migration ability is significantly weakened when co-cultured with EC cells. Therefore, we believe that β-Klotho influences macrophage migration by regulating the expression of CSF-1, thereby interfering with the progression of EC. We investigated in depth the mechanism of β-Klotho regulating CSF-1 secretion and found that β-Klotho inhibits the phosphorylation of p65, which blocked the nuclear translocation of p65, thereby inhibiting the secretion of CSF-1 by EC cells. The above results indicate that β-Klotho-mediated inhibition of CSF-1 secretion reduces the migration of macrophages to tumor tissue and delays the progression of EC.

Tumor Microenvironment: Implications in Melanoma Resistance to Targeted Therapy and Immunotherapy

Simple Summary

The response to pharmacological treatments is deeply influenced by the tight interactions between the tumor cells and the microenvironment. In this review we describe, for melanoma, the most important mechanisms of resistance to targeted therapy and immunotherapy mediated by the components of the microenvironment. In addition, we briefly describe the most recent therapeutic advances for this pathology. The knowledge of molecular mechanisms, which are underlying of drug resistance, is fundamental for the development of new therapeutic approaches for the treatment of melanoma patients.

Abstract

Antitumor therapies have made great strides in recent decades. Chemotherapy, aggressive and unable to discriminate cancer from healthy cells, has given way to personalized treatments that, recognizing and blocking specific molecular targets, have paved the way for targeted and effective therapies. Melanoma was one of the first tumor types to benefit from this new care frontier by introducing specific inhibitors for v-Raf murine sarcoma viral oncogene homolog B (BRAF), mitogen-activated protein kinase kinase (MEK), v-kit Hardy–Zuckerman 4 feline sarcoma viral oncogene homolog (KIT), and, recently, immunotherapy. However, despite the progress made in the melanoma treatment, primary and/or acquired drug resistance remains an unresolved problem. The molecular dynamics that promote this phenomenon are very complex but several studies have shown that the tumor microenvironment (TME) plays, certainly, a key role. In this review, we will describe the new melanoma treatment approaches and we will analyze the mechanisms by which TME promotes resistance to targeted therapy and immunotherapy.

Diabetes mellitus is independently associated with adverse clinical outcome in soft tissue sarcoma patients

Diabetes mellitus (DM) and hyperglycemia are known predictors of adverse outcome in different tumor entities. The present study investigated the effect of DM and pre-surgery blood glucose levels on cancer specific survival (CSS), overall survival (OS), and disease-free survival (DFS) in non-metastatic soft tissue sarcoma (STS) patients. A total of 475 STS patients who underwent curative resection were included in this retrospective study. CSS, DFS, and OS were assessed using Kaplan-Meier curves. The association between pre-existing DM as well as mean pre-surgery blood glucose levels and all 3 survival endpoints was analyzed using Cox-hazard proportional (for OS and DFS) and competing risk regression models (for CSS). In unadjusted analysis, DM was significantly associated with adverse CSS (sub-hazard ratio [SHR]: 2.14, 95% confidence interval [CI] 1.18-3.90, p = 0.013) and OS (hazard ratio [HR]: 2.05, 95% CI 1.28-3.28) and remained significant after adjusting for established prognostic factors (CSS: adjusted SHR 2.33, 95% CI 1.21-4.49, p = 0.012; OS: adjusted HR 1.96, 95% CI 1.17-3.28, p = 0.010), respectively. There was no significant association of DM with DFS (p = 0.149). The mean pre-surgery glucose levels were not significantly associated with inferior outcome (CSS: p = 0.510, OS: p = 0.382 and DFS: p = 0.786). This study shows, that DM represents a negative prognostic factor for clinical outcome in STS patients after curative resection.

Hematologic Markers of Lung Metastasis in Stage IV Colorectal Cancer

BACKGROUND

Many studies showed an association between absolute neutrophil count (ANC), absolute monocyte count (AMC), neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) with poor overall survival (OS) in patients with cancer. However, only a few studies were conducted to further investigate this association in colorectal cancer (CRC).

METHODS

Clinical data from 299 stage IV CRC patients treated at King Hussein Cancer Center from 2004 to 2012 have been retrospectively reviewed. We examined the association between ANC, AMC, MLR, PLR, and NLR with lung metastasis in stage IV CRC. Receiver Operating Characteristic (ROC) curve analysis was operated to determine the optimal NLR cutoff value. Univariate and multivariate analysis were performed.

RESULTS

The ROC value of 3.4 was determined as the cutoff value of NLR to study the association. Univariate and multivariate analysis showed that patients with high baseline NLR (≥ 3.4) had more baseline lung metastasis than patients with low NLR (< 3.4) (p = 0.0001, p = 0.0151, respectively). Also, baseline NLR correlated significantly with the presence of lymphovascular invasion (p = 0.001). In patients with no baseline lung metastasis, high post-treatment NLR was associated with consequent development of lung metastasis (p = 0.0227). Other markers including ANC, AMC, MLR, and PLR were significantly associated with lung metastasis at time of diagnosis (p = 0.0006, p = 0.0006, p = 0.0187, and p = 0.001, respectively).

CONCLUSION

Results are suggesting that different hematologic markers obtained from a cheap test (CBC) could potentially be used to predict the likelihood of lung metastasis in stage IV CRC. Prospective studies are needed to further assess the immune cells' role in tumor metastasis promotion.

Colony‑stimulating factor 1 receptor inhibition blocks macrophage infiltration and endometrial cancer cell proliferation

Tumor-associated macrophages (TAMs) promote the progression of endometrial cancer (EC), but the mechanism of TAM in EC cell proliferation remains unclear. It was found that colony stimulating factor (CSF)-1 and CSF-1 receptor (CSF-1R) were highly expressed in EC tissues of patients and two EC cell lines (ECC-1 and HEC-1A). Using wound-healing and chemotactic migration assays to evaluate the role of EC cells in the induction of macrophage migration, it was found that the supernatant of EC cells promoted macrophage cell line (U937) migration; however, the migration capacity of U937 weakened when CSF-1R was blocked. Subsequently, inhibition of CSF-1 expression in EC cells also restrained U937 migration. Additionally, blocking CSF-1R by PLX3397 treatment in U937 cells inhibited EC cell proliferation in a co-culture system by inhibiting the expression of proliferation-associated proteins (Janus kinase-1, phosphoinositide 3-kinase, AKT, cyclin kinase 2, 4 and retinoblastoma-associated protein). Together, these results demonstrated that CSF-1 secreted by EC cells promoted macrophage migration; similarly, CSF-1-stimulated macrophages promoted EC cell proliferation. These results suggested that the interaction between CSF-1 and its receptor served an important role in promoting macrophage infiltration and progression of EC.

Hematologic markers of distant metastases and poor prognosis in gynecological cancers

Background

Despite the recent progress in the development of anti-cancer drugs, the treatment of metastatic tumors is usually ineffective. The systemic inflammatory response performs key roles in different stages of the carcinogenesis process including metastasis. The high neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) were found to be associated with poor survival rates in the majority of solid tumors. However, only a few studies were conducted to further investigate this association in patients with advanced gynecological cancers.

Methods

Clinical data from 264 patients with FIGO stage III and IV gynecological (endometrial, ovarian and cervical) cancers treated at King Hussein Cancer Center (Amman-Jordan) from 2006 to 2012 were retrospectively reviewed. We examined the association between absolute neutrophil count (ANC), absolute monocyte count (AMC), MLR, PLR, and NLR with distant metastases, overall survival and event-free survival in gynecological cancers. For survival analysis, Receiver Operating Characteristic (ROC) curve analysis was operated to determine the optimal cutoff values.

Results

Patients with high baseline NLR (≥4.1) had more baseline distant metastases than patients with low baseline NLR (< 4.1), (p-value 0.045). Patients with high baseline AMC (≥560) had more distant metastases in comparison to patients with low baseline AMC (< 560), (p-value 0.040). Furthermore, Patients with high baseline PLR (≥0.3) had more distant metastases in comparison to patients with low baseline PLR (< 0.3), (p-value 0.025). Additionally, patients with high baseline ANC (≥5700) had worse overall survival compared to the patients with low baseline ANC (< 5700), (p-value 0.015). Also, patients with high baseline AMC (≥490) had worse overall survival compared to the patients with low baseline AMC (< 490), (p-value 0.044).

Conclusion

Different hematologic markers obtained from a cheap test (CBC) could potentially be used to predict the presence of distant metastases thus used as prognostic indices in gynecological cancers.

Tumor-Associated T-Lymphocytes and Macrophages are Decreased in Endometrioid Endometrial Carcinoma with MELF-Pattern Stromal Changes

Microcystic, elongated, fragmented (MELF)-pattern is an unusual morphology of myometrial invasive front in endometrioid endometrial carcinoma (EA). The aim of the study was to investigate potential correlation between MELF-pattern and peritumoral inflammatory immune response. A total of 96 out of 368 patients were included in this study. CD3, CD20, CD57. CD68 and S100 markers were used for the detection of tumor-associated T-lymphocytes (TAT), tumor-associated B-lymphocytes (TAB), tumor-associated NK-lymphocytes (NK), tumor-associated macrophages and dendritic cells respectively. Mann-Whitney tests, receiver operating characteristic (ROC) curve analysis, and Spearman correlation were used as methods for statistical analyses. Odds ratio with 95% confidence interval (95% CI) was determined with the use of a logistic regression model. A p < 0.05 was considered statistically significant. Our results suggested that the number of CD3 and CD68 cells were significantly lower (p < 0.001) in cases of endometrioid carcinoma with MELF-pattern. A significant correlation between the presence of MELF-pattern and decrease of CD3 positive T-lymphocytes (r = 0.691; p < 0.001) was also observed. Additionally, we found an inverse correlation between the presence of MELF-pattern and TAM (r = 0.568; p = 0.001). Therefore, our data suggest that MELF-pattern may be associated with EA stroma fibrosis that contains immune cells infiltration and demonstrated a decrease in the number of TAT and TAM cells. This may indicate the poor clinical prognosis of this disease.

Pancreatic cancer cell/fibroblast co-culture induces M2 like macrophages that influence therapeutic response in a 3D model

Pancreatic cancer (PC) remains one of the most challenging solid tumors to treat with a high unmet medical need as patients poorly respond to standard-of-care-therapies. Prominent desmoplastic reaction involving cancer-associated fibroblasts (CAFs) and the immune cells in the tumor microenvironment (TME) and their cross-talk play a significant role in tumor immune escape and progression. To identify the key cellular mechanisms induce an immunosuppressive tumor microenvironment, we established 3D co-culture model with pancreatic cancer cells, CAFs and monocytes. Using this model, we analyzed the influence of tumor cells and fibroblasts on monocytes and their immune suppressive phenotype. Phenotypic characterization of the monocytes after 3D co-culture with tumor/fibroblast spheroids was performed by analyzing the expression of defined cell surface markers and soluble factors. Functionality of these monocytes and their ability to influence T cell phenotype and proliferation was investigated. 3D co-culture of monocytes with pancreatic cancer cells and fibroblasts induced the production of immunosuppressive cytokines which are known to promote polarization of M2 like macrophages and myeloid derived suppressive cells (MDSCs). These co-culture spheroid polarized monocyte derived macrophages (MDMs) were poorly differentiated and had an M2 phenotype. The immunosuppressive function of these co-culture spheroids polarized MDMs was demonstrated by their ability to inhibit CD4+ and CD8+ T cell activation and proliferation in vitro, which we could partially reverse by 3D co-culture spheroid treatment with therapeutic molecules that are able to re-activated spheroid polarized MDMs or block immune suppressive factors such as Arginase-I.

Relationship between the inflammatory infiltrate and the degree of differentiation of the canine cutaneous squamous cell carcinoma

The inflammatory response may have pro or anti-neoplastic effects in tumors, depending on the histological type and malignancy level of the tumor. This study aimed to evaluate the profile of predominant inflammatory cells by immunohistochemistry in cutaneus squamous cell carcinoma (SCC) of dogs, comparing it with the degree of differentiation of the tumor. Twenty samples of SCC were analyzed. The tumors were histologically classified into two groups, differentiated SCC (SCCd=12) and undifferentiated SCC (SCCu=08). The tumor inflammatory infiltrate was determined by immunohistochemistry, in order to identify macrophages, lymphocytes and plasma cells. The comparison between groups, SCCd and SCCu, was not significant concerning the density of macrophages (P=1.0), T lymphocytes (P=0.335) and plasma cells (P=0.075). However, when comparing the inflammatory infiltrate in each group, the macrophages were the predominant cell type in both groups, a significant difference was found in the SCCd with plasma cells (P<0.0001). In the SCCu the difference occurred with lymphocytes (P<0.05) and plasma cells (P=0.0006). It could be concluded that the presence of inflammation in cases of SCC does not play a role in the differentiation of the neoplasm, since the inflammatory infiltrate was similar in both groups of SCC.

Surface antigen expression on peripheral blood monocytes in women with gynecologic malignancies

Background

Of many specialized blood cells, monocytes are gaining increasing attention for their role in neoplastic disorders. The purpose of the present investigation was to determine the expression of selected peripheral blood monocyte surface antigens in cases of cervical, endometrial, and ovarian cancers. In addition, our aim was to validate the diagnostic value of two artificial coefficients recently proposed for the diagnosis of gynecologic malignancies: Neutrophil to Lymphocyte Ratio (NLR), and Multiplication of Neutrophil and Monocyte Counts (MNM).

Methods

We studied 69 white Caucasian women with histopathologic confirmation of endometrial (N = 42), cervical (N = 13), and ovarian (N = 14) cancers. Reference Group I were women suspected of cancer but histologically nullified (N = 20), and Group II were healthy blood donors (N = 23). Expression of CD11a, CD11b, CD11c, CD16, CD54 (ICAM-1), CD62 L (L-selectin), CD64, and HLA-DR was measured with immunofluorescence in a flow cytometer.

Results

CD54 expression increased by ≥35.6% (p < 0.001) whilst HLA-DR decreased by ≥10.8% (p < 0.001) in all cancer subgroups and Group I as compared to blood donors. A correlation (p < 0.05) between CD54 and CD62 L was stronger in all cancers studied than in healthy subjects. There was no difference in the NLR values between any of these subgroups. Moreover, we observed an increase in MNM parameter in cases of cervical and endometrial cancer and in the Reference Group I.

Conclusions

In the studied gynecologic malignancies, CD54 expression on peripheral blood monocytes is enhanced, indicating a higher transmigrational potential present in such patients, and HLA-DR expression diminished, indicating a decreased readiness of the immune system to recognize foreign antigens. The more pronounced correlation for the expression of CD54 and CD62 L in cancer suggests that monocytes uptake from the bloodstream and their local adhesion increase the pool of tumor-associated macrophages. This study challenged the suggested credibility and usefulness of the artificial parameters of MNM and NLR for the differential diagnosis of gynecologic malignancies.

Propofol exerts anti-hepatocellular carcinoma by microvesicle-mediated transfer of miR-142-3p from macrophage to cancer cells

OBJECTIVE

We previously confirmed that propofol directly inhibited the viability, proliferation, and invasiveness of hepatocellular carcinoma cells in vitro. In this study, we investigated the mechanism underlying the anti-HCC effects of propofol.

METHODS

In vivo antitumor activity was investigated in tumor-bearing mice following an intraperitoneal injection of propofol, with or without clodrolip. The co-culture system was used to verify that miR-142-3p was transported from macrophages to HCC cells. A miR-142-3p inhibitor was used to down-regulate the expression of miR-142-3p.

RESULTS

Propofol drastically inhibited tumor growth in tomor-bearing mice through macrophage activation, and stimulated tumor-associated macrophages (TAMs) to secrete microvesicles (MVs), which delivered miR-142-3p to HCC cells, resulting in the inhibition of HCC cell invasion. In addition, MVs collected from the plasma of the tumor-bearing mice injected with propofol suppressed tumor growth. More importantly, down-regulation of the expression miR-142-3p reversed the effect of propofol on HCC cell migration.

CONCLUSIONS

This study reveals a novel role for propofol in the inhibition of HCC through MV-mediated transfer of miR-142-3p from macrophages to cancer cells in vivo.

Addition of magnesium chloride to enhance mono-dispersity of a coiled-coil recombinant mouse macrophage protein

X-ray crystallography for the determination of three-dimensional structures of protein macromolecules represents an important tool in function assignment of uncharacterized proteins. However, crystallisation is often difficult to achieve. A protein sample fully characterized in terms of dispersity may increase the likelihood of successful crystallisation by improving the predictability of the crystallisation process. To maximize the probability of crystallisation of a novel mouse macrophage protein (rMMP), target molecule was characterized and refined to improve monodispersity. Addition of MgCl2 at low concentrations resolves the rMMP into a monodisperse solution, and finally successful crystallization of rMMP was achieved. The effect of MgCl2 was studied using gel filtration chromatography and dynamic light scattering.

IGFBP-4 anti-angiogenic and anti-tumorigenic effects are associated with anti-cathepsin B activity

Insulin-like growth factor-binding protein 4 (IGFBP-4/IBP-4) has potent IGF-independent anti-angiogenic and antitumorigenic effects. In this study, we demonstrated that these activities are located in the IGFBP-4 C-terminal protein fragment (CIBP-4), a region containing a thyroglobulin type 1 (Tg1) domain. Proteins bearing Tg1 domains have been shown to inhibit cathepsins, lysosomal enzymes involved in basement membrane degradation and implicated in tumor invasion and angiogenesis. In our studies, CIBP-4 was shown to internalize and co-localize with lysosomal-like structures in both endothelial cells (ECs) and glioblastoma U87MG cells. CIBP-4 also inhibited both growth factor-induced EC tubulogenesis in Matrigel and the concomitant increases in intracellular cathepsin B (CatB) activity. In vitro assays confirmed CIBP-4 capacity to block recombinant CatB activity. Biodistribution analysis of intravenously injected CIBP-4-Cy5.5 in a glioblastoma tumor xenograft model indicated targeted accumulation of CIBP-4 in tumors. Most importantly, CIBP-4 reduced tumor growth in this animal model by 60%. Pleiotropic anti-angiogenic and anti-tumorigenic activities of CIBP-4 most likely underlie its observed therapeutic potential against glioblastoma.

Muscle wasting in cancer

Skeletal muscle loss appears to be the most significant clinical event in cancer cachexia and is associated with a poor outcome. With regard to such muscle loss, despite extensive study in a range of models, there is ongoing debate as to whether a reduction in protein synthesis, an increase in degradation or a combination of both is the more relevant. Each model differs in terms of key mediators and the pathways activated in skeletal muscle. Certain models do suggest that decreased synthesis accompanied by enhanced protein degradation via the ubiquitin proteasome pathway (UPP) is important. Murine models tend to involve rapid development of cachexia and may represent more acute muscle atrophy rather than the chronic wasting observed in humans. There is a paucity of human data both at a basic descriptive level and at a molecular/mechanism level. Progress in treating the human form of cancer cachexia can only move forwards through carefully designed large randomised controlled clinical trials of specific therapies with validated biomarkers of relevance to underlying mechanisms. This article is part of a Directed Issue entitled: Molecular basis of muscle wasting.

FOXM1 (Forkhead box M1) in tumorigenesis: overexpression in human cancer, implication in tumorigenesis, oncogenic functions, tumor-suppressive properties, and target of anticancer therapy

FOXM1 (Forkhead box M1) is a typical proliferation-associated transcription factor and is also intimately involved in tumorigenesis. FOXM1 stimulates cell proliferation and cell cycle progression by promoting the entry into S-phase and M-phase. Additionally, FOXM1 is required for proper execution of mitosis. In accordance with its role in stimulation of cell proliferation, FOXM1 exhibits a proliferation-specific expression pattern and its expression is regulated by proliferation and anti-proliferation signals as well as by proto-oncoproteins and tumor suppressors. Since these factors are often mutated, overexpressed, or lost in human cancer, the normal control of the foxm1 expression by them provides the basis for deregulated FOXM1 expression in tumors. Accordingly, FOXM1 is overexpressed in many types of human cancer. FOXM1 is intimately involved in tumorigenesis, because it contributes to oncogenic transformation and participates in tumor initiation, growth, and progression, including positive effects on angiogenesis, migration, invasion, epithelial-mesenchymal transition, metastasis, recruitment of tumor-associated macrophages, tumor-associated lung inflammation, self-renewal capacity of cancer cells, prevention of premature cellular senescence, and chemotherapeutic drug resistance. However, in the context of urethane-induced lung tumorigenesis, FOXM1 has an unexpected tumor suppressor role in endothelial cells because it limits pulmonary inflammation and canonical Wnt signaling in epithelial lung cells, thereby restricting carcinogenesis. Accordingly, FOXM1 plays a role in homologous recombination repair of DNA double-strand breaks and maintenance of genomic stability, that is, prevention of polyploidy and aneuploidy. The implication of FOXM1 in tumorigenesis makes it an attractive target for anticancer therapy, and several antitumor drugs have been reported to decrease FOXM1 expression.

Macrophage-elicited loss of estrogen receptor-α in breast cancer cells via involvement of MAPK and c-Jun at the ESR1 genomic locus

Estrogen receptor-α (ERα, ESR1) is a pivotal transcriptional regulator of breast cancer physiology and is targeted by endocrine therapies. Loss of ERα activity or expression is an indication of endocrine resistance and is associated with increased risk of tumor recurrence and worse prognosis. In this study, we sought to investigate whether elements of the tumor microenvironment, namely macrophages, would impact on ERα and we found that macrophage-derived factors caused loss of ERα expression in breast cancer cells. Conditioned media from macrophages caused activation of several intracellular pathways in breast cancer cells of which c-Src, protein kinase c and mitogen-activated protein kinase (MAPK) were essential for loss of ERα expression. Moreover, a prolonged hyperactivation of MAPK was observed. The activation of this kinase cascade resulted in recruitment of extracellular signal regulated kinase 2 (ERK2) directly to chromatin at the ESR1 gene locus in a process that was dependent upon activation and recruitment of the c-Jun transcription factor. Thus, we identify a novel mechanism for loss of ERα expression in breast cancer cells via macrophage activation of kinase cascades in the cancer cells causing transcriptional repression of the ESR1 gene by a direct chromatin action of a c-Jun/ERK2 complex. The findings in this study support an alternative mechanism, not intrinsic to the tumor cell but derived from the cross-talk with the tumor microenvironment, that could lead to endocrine resistance and might be targeted therapeutically to prevent loss of ERα expression in breast tumors.

Serum biomarker panels for the diagnosis of gastric adenocarcinoma

Background:

Currently, serum biomarkers, which are sufficiently sensitive and specific for early detection and risk classification of gastric adenocarcinoma do not exist. Therefore, this study identified a panel of serum biomarkers for the diagnosis of gastric adenocarcinoma.

Methods:

A 29-plex array platform with 29 biomarkers, consisting of 11 proteins discovered through proteomics and 18 previously known to be cancer-associated, was constructed. A test/training set consisting of 120 gastric adenocarcinoma and 120 control samples were examined. After 13 proteins were selected as candidate biomarkers, multivariate classification analyses were used to identify algorithms for diagnostic biomarker combinations. These algorithms were independently validated using a set of 95 gastric adenocarcinoma and 51 control samples.

Results:

Epidermal growth factor receptor (EGFR), pro-apolipoprotein A1 (proApoA1), apolipoprotein A1, transthyretin (TTR), regulated upon activation, normally T-expressed and presumably secreted (RANTES), D-dimer, vitronectin (VN), interleukin-6, α-2 macroglobulin, C-reactive protein and plasminogen activator inhibitor-1 were selected as classifiers in the two algorithms. These algorithms differentiated between the majority of gastric adenocarcinoma and control serum samples in the training/test set with high accuracy (>88%). These algorithms also accurately classified in the validation set (>85%).

Conclusion:

Two panels of combinatorial biomarkers, including EGFR, TTR, RANTES, and VN, are developed, which are less invasive method for the diagnosis of gastric adenocarcinoma. They could supplement clinical gastroscopic evaluation of symptomatic patients to enhance diagnostic accuracy.

Activated macrophages containing tumor marker in colon carcinoma: immunohistochemical proof of a concept

The presence of carcinoembryonic antigen (CEA)-containing activated macrophages has been demonstrated in peripheral blood from patients with colorectal carcinoma. Macrophages migrate from the circulation into the tissue, phagocytose debris, and return to the bloodstream. Hence it seems likely that activated macrophages containing tumor debris, i.e., tumor marker, are present in the stroma of colorectal carcinoma. After phagocytosis, they could follow a hematogenic or lymphogenic route to the peripheral blood. The aim of this study is to assess the presence of tumor marker-containing activated macrophages in the stroma of colon carcinoma and in regional lymph nodes. From 10 cases of colon carcinoma, samples of tumor tissue and metastasis-free lymph nodes were cut in serial sections and stained for CD68 to identify macrophages and for CEA, cytokeratin, or M30 presence. Slides were digitalised and visually inspected using two monitors, comparing the CD68 stain to the tumor marker stain to evaluate the presence of tumor marker-positive macrophages. Macrophages containing tumor marker could be identified in tumor stroma and in metastasis-free regional lymph nodes. The distribution varied for the different markers, CEA-positive macrophages being most abundant. The presence of macrophages containing tumor marker in the tumor stroma and lymph nodes from patients with colon carcinoma could be confirmed in this series using serial immunohistochemistry. This finding supports the concept of activated macrophages, after phagocytosing cell debris, being transported or migrating through the lymphatic system. These results support the potential of tumor marker-containing macrophages to serve as a marker for diagnosis and follow-up of colon cancer patients.

Cell surface markers in colorectal cancer prognosis

The classification of colorectal cancers (CRC) is currently based largely on histologically determined tumour characteristics, such as differentiation status and tumour stage, i.e., depth of tumour invasion, involvement of regional lymph nodes and the occurrence of metastatic spread to other organs. These are the conventional prognostic factors for patient survival and often determine the requirement for adjuvant therapy after surgical resection of the primary tumour. However, patients with the same CRC stage can have very different disease-related outcomes. For some, surgical removal of early-stage tumours leads to full recovery, while for others, disease recurrence and metastasis may occur regardless of adjuvant therapy. It is therefore important to understand the molecular processes that lead to disease progression and metastasis and to find more reliable prognostic markers and novel targets for therapy. This review focuses on cell surface proteins that correlate with tumour progression, metastasis and patient outcome, and discusses some of the challenges in finding prognostic protein markers in CRC.

The TGF-beta superfamily cytokine MIC-1/GDF15: secretory mechanisms facilitate creation of latent stromal stores

Macrophage inhibitory cytokine-1/growth differentiation factor 15 (MIC-1/GDF15), a divergent member of the TGF-beta superfamily is induced by a range of proinflammatory cytokines and oxidized low-density lipoprotein (oxLDL) and is highly expressed in macrophages in atherosclerotic and tumor lesions. MIC-1/GDF15, a major p53 target gene, is largely described to have anti-tumorigenic activity and more recently high MIC-1/GDF15 serum levels in late stage cancer were shown to be the major cause of cancer-associated weight loss. MIC-1/GDF15 serum levels independently predict both atherosclerotic events and severity of rheumatoid arthritis (RA), suggesting serum levels are important in modifying disease expression. Controlling serum levels is the ratio of latent unprocessed MIC-1/GDF15 stromal stores to soluble mature MIC-1/GDF15 generated by the cell. Here, we investigate MIC-1/GDF15 secretion from U937 monocytoid cells and identify novel mechanisms designed to ensure secretion of unprocessed cytokine and creation of latent stromal stores. We find that endogenous MIC-1/GDF15 is secreted as both processed and unprocessed forms. Pulse chase analysis of MIC-1/GDF15 secretion reveals that unprocessed MIC-1/GDF15 precursor is rapidly secreted, while mature MIC-1/GDF15 generated within the cell by intracellular processing is secreted much slower, possibly via an alternate secretory route. The COOH-T 47 amino acids of the propeptide are responsible for rapid secretion of MIC-1/GDF15 precursor and this effect occurs in the trans-Golgi network (TGN)/post TGN compartment. Thus, variations in MIC-1/GDF15 intracellular processing, regulating the presence or absence of propeptide, are a powerful mechanism modulating rate of MIC-1/GDF15 secretion and proMIC-1/GDF15 stromal storage, with major impact on circulating levels of mature MIC-1/GDF15.

Novel membrane-permeable contrast agent for brain tumor detection by MRI

One of the key challenges hindering the clinical intervention against brain cancer is defined by the inability to detect brain tumors at an early enough stage to permit effective therapy. Furthermore, the rapid growth and severe lethality of this form of cancer predicate the vital importance of monitoring the development of the pathology and its outcome after therapeutic intervention. With this in mind, we designed a novel membrane-permeant contrast agent, MN-MPAP-Cy5.5, which consists of a superparamagnetic iron oxide core, for MRI conjugated to myristoylated polyarginine peptides, as a membrane translocation module and labeled with the near-infrared dye Cy5.5 for correlative microscopy. This probe showed a remarkable uptake by U-87 human glioma cells in vitro and localized and delineated stereotactically injected tumor in vivo by MRI. Our findings suggest that the agent mediates its effects by translocation of the magnetic nanoparticles label across the leaky tumor vasculature, followed by enhanced accumulation in tumor cells. The noninvasive detection of brain tumors when they are still small represents a formidable challenge from an imaging standpoint. Our study describes an improved strategy to detect brain lesions by utilizing a contrast agent with membrane translocation properties.

Reciprocal regulation of activating and inhibitory Fc{gamma} receptors by TLR7/8 activation: implications for tumor immunotherapy

PURPOSE

Activation of Toll-like receptors (TLR) 7 and 8 by engineered agonists has been shown to aid in combating viruses and tumors. Here, we wished to test the effect of TLR7/8 activation on monocyte Fcgamma receptor (FcgammaR) function, as they are critical mediators of antibody therapy.

EXPERIMENTAL DESIGN

The effect of the TLR7/8 agonist R-848 on cytokine production and antibody-dependent cellular cytotoxicity by human peripheral blood monocytes was tested. Affymetrix microarrays were done to examine genomewide transcriptional responses of monocytes to R-848 and Western blots were done to measure protein levels of FcgammaR. Murine bone marrow-derived macrophages from WT and knockout mice were examined to determine the downstream pathway involved with regulating FcgammaR expression. The efficacy of R-848 as an adjuvant for antibody therapy was tested using a CT26-HER2/neu solid tumor model.

RESULTS

Overnight incubation with R-848 increased FcgammaR-mediated cytokine production and antibody-dependent cellular cytotoxicity in human peripheral blood monocytes. Expression of FcgammaRI, FcgammaRIIa, and the common gamma-subunit was increased. Surprisingly, expression of the inhibitory FcgammaRIIb was almost completely abolished. In bone marrow-derived macrophage, this required TLR7 and MyD88, as R-848 did not increase expression of the gamma-subunit in TLR7(-/-) nor MyD88(-/-) cells. In a mouse solid tumor model, R-848 treatment superadditively enhanced the effects of antitumor antibody.

CONCLUSIONS

These results show an as-yet-undiscovered regulatory and functional link between the TLR7/8 and FcgammaR pathways. This suggests that TLR7/8 agonists may be especially beneficial during antibody therapy.

Synergistic anti-inflammatory effects of low doses of curcumin in combination with polyunsaturated fatty acids: docosahexaenoic acid or eicosapentaenoic acid

Inflammatory response plays an important role not only in the normal physiology but also in the pathology such as cancers. As chronic inflammations are associated with malignancies, it is important to prevent inflammation-mediated neoplastic formation, promotion and/or progression. One possible intervention will be using cancer chemopreventive agents such as curcumin (CUR), a potent anti-inflammatory and anti-oxidative stress compound. Polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) are potent anti-inflammatory agents by decreasing the production of inflammatory eicosanoids, cytokines, and reactive oxygen species (ROS). The present study aims at examining whether CUR with DHA or EPA would have synergistic anti-inflammatory effects in RAW 264.7 cells. Non-toxic concentrations of single and combination of the compounds were investigated at 6, 12 and 24h. The nitric oxide (NO) suppression effects were most prominent at 24h. All the combinations of CUR and DHA or EPA with lower concentrations of CUR 5 microM and 25 microM of DHA or EPA were found to have synergistic effects in suppressing LPS-stimulated NO and endogenous NO levels. Importantly, very low doses of CUR 2.5 microM and DHA or EPA of 0.78 microM could synergistically suppress the LPS-induced prostaglandin E(2) (PGE(2)). The combinations were also found to suppress iNOS, COX-2, 5-lipoxygenase (5-LOX) and cPLA(2) but induce HO-1. Taken together, the present study clearly shows the synergistic anti-inflammatory as well as anti-oxidative stress effects of CUR and PUFA.

Cachexia, survival and the acute phase response

PURPOSE OF REVIEW

To review current knowledge of the relationship between cytokines, the acute phase response (APR) and the development of cachexia.

RECENT FINDINGS

Cytokines important in the initiation of the APR are also important in the genesis of cachexia. The presence of an APR or high circulating levels of pro-inflammatory cytokines are known to be related to adverse outcome in cancer patients. Studies of host cytokine genotype have demonstrated that specific host cytokine polymorphisms are associated with both the development of cachexia and reduced patient survival. The desire to be able to predict accurately survival in cancer patients has led to the description of various APR-based prognostic scoring systems.

SUMMARY

Cachexia is an important clinical problem affecting up to two thirds of cancer patients. It results from anorexia and metabolic change and leads to loss of both adipose tissue and lean body mass, particularly in the skeletal muscle compartment. An APR is seen in half of cancer patients at presentation, and is most often determined clinically by raised plasma C-reactive protein concentrations. Adverse outcome and shortened survival have been linked to the presence of an APR. This article explores the cause and consequences of the APR in cancer cachexia.

Ecological therapy for cancer: defining tumors using an ecosystem paradigm suggests new opportunities for novel cancer treatments

We propose that there is an opportunity to devise new cancer therapies based on the recognition that tumors have properties of ecological systems. Traditionally, localized treatment has targeted the cancer cells directly by removing them (surgery) or killing them (chemotherapy and radiation). These modes of therapy have not always been effective because many tumors recur after these therapies, either because not all of the cells are killed (local recurrence) or because the cancer cells had already escaped the primary tumor environment (distant recurrence). There has been an increasing recognition that the tumor microenvironment contains host noncancer cells in addition to cancer cells, interacting in a dynamic fashion over time. The cancer cells compete and/or cooperate with nontumor cells, and the cancer cells may compete and/or cooperate with each other. It has been demonstrated that these interactions can alter the genotype and phenotype of the host cells as well as the cancer cells. The interaction of these cancer and host cells to remodel the normal host organ microenvironment may best be conceptualized as an evolving ecosystem. In classic terms, an ecosystem describes the physical and biological components of an environment in relation to each other as a unit. Here, we review some properties of tumor microenvironments and ecological systems and indicate similarities between them. We propose that describing tumors as ecological systems defines new opportunities for novel cancer therapies and use the development of prostate cancer metastases as an example. We refer to this as "ecological therapy" for cancer.