Circulating tumor cells promote the metastatic colonization of disseminated carcinoma cells by inducing systemic inflammation

Neutrophils in triple-negative breast cancer: an underestimated player with increasingly recognized importance

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer, with limited therapeutic options readily available. Immunotherapy such as immune checkpoint inhibition has been investigated in TNBC but still encounters low overall response. Neutrophils, the most abundant leukocytes in the body, are increasingly recognized as an active cancer-modulating entity. In the bloodstream, neutrophils escort circulating tumor cells to promote their survival and stimulate their proliferation and metastasis. In the tumor microenvironment, neutrophils modulate the immune milieu through polarization between the anti-tumor and the pro-tumor phenotypes. Through a comprehensive review of recently published literature, it is evident that neutrophils are an important player in TNBC immunobiology and can be used as an important prognostic marker of TNBC. Particularly, in their pro-tumor form, neutrophils facilitate TNBC metastasis through formation of neutrophil extracellular traps and the pre-metastatic niche. These findings will help advance the potential utilization of neutrophils as a therapeutic target in TNBC.

Postoperative serum interleukin-6 levels correlate with survival in stage I-III colorectal cancer

AIMS

The preoperative serum levels of inflammatory mediators, including C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6), have been demonstrated to be correlated with patient outcomes in colorectal cancer (CRC); however, the prognostic role of these levels has been less well-studied in postoperative settings.

MATERIALS AND METHODS

A total of 122 stage I-III CRC patients were retrospectively enrolled. Serum levels of CRP, PCT and IL-6 were measured after surgery, and their prognostic value was evaluated. Kaplan-Meier analysis was used to determine the differences in disease-free survival (DFS) and overall survival (OS) between patients with different levels of these mediators, and the Cox proportional hazards model was used to estimate the risk factors.

RESULTS

In contrast to CRP and PCT, only the level of IL-6 was significant in predicting DFS (P = 0.01) but not OS (P = 0.07). A total of 66.39% (81/122) of patients were assigned to the low IL-6 group and no significant differences were found in the collected clinicopathological parameters among the low or high IL-6 subgroups. The level of IL-6 was negatively correlated with postoperative (1 w) (R=-0.24, P = 0.02) absolute lymphocyte counts. Patients with low levels of IL-6 had better DFS (log rank = 6.10, P = 0.01) but not OS (log rank = 2.28, P = 0.13). Finally, the level of IL-6 was an independent risk factor for DFS (HR: 1.81, 95% CI: 1.03-3.15, P = 0.04).

CONCLUSIONS

Compared to CRP and PCT, the level of IL-6 was observed to be the only significant factor in predicting the prognosis of stage I-III CRC patients after surgery, and a low level of IL-6 was associated with good DFS.

The imbalance of liver resident macrophages polarization promotes chronic autoimmune hepatitis development in mice

Background

Autoimmune hepatitis (AIH) is a chronic immune-mediated inflammatory liver disease. At present, it is largely unknown how the innate immune cells influence AIH development.

Objective

To inquiry about mechanism of liver resident macrophages in AIH development, thus offering a new direction for AIH targeted treatment.

Methods

The liver resident macrophages were eliminated by clodronate liposomes in AIH liver tissues, followed by HE and Picrosirius assay to detect liver fibrosis and lymphocyte infiltration. The liver resident macrophages polarization was detected by Immunohistochemistry and qPCR. The collagenase digestion was used to isolate Kupffer cells from AIH mice liver tissues and pro-/anti-inflammatory cytokines were determined by qPCR.

Results

M2 macrophages were the dominant phenotype at early immune response stage and hepatic inflammation was progressively aggravated after depletion of liver resident macrophages. M2 macrophages could effectively delay the development of AIH and could be polarized to M1 macrophages at the disease progresses. TLR2 ligands could promote M2 macrophages producing anti-inflammatory cytokines, whereas TLR4 ligands could promote M1 macrophages producing proinflammatory cytokines. The change of TLR2 and TLR4 ligands could lead to continuous high expression of TLR4 and decreased expression of TLR2 in macrophages to further affect liver resident macrophages polarization state.

Conclusion

TLR2 and TLR4 ligands mediated liver resident macrophages polarization to favor chronic autoimmune hepatitis development.

Combination of Preoperative Circulating Tumor Cell Count and Neutrophil-Lymphocyte Ratio for Prognostic Prediction in Hepatocellular Carcinoma Patients after Curative Hepatectomy

Background

Both the preoperative neutrophil-lymphocyte ratio (NLR) and circulating tumor cell count (CTC) are associated with poor prognosis in hepatocellular carcinoma (HCC). The purpose of this study was to explore the prognostic value of these two indices (CTC-NLR) in HCC.

Methods

We retrospectively collected demographic and clinical data, including NLR and CTC, from 97 patients with HCC who underwent curative hepatectomy at our institution from March 2014 to May 2017. X-Tile software was used to confirm the optimal cut-off value of NLR and CTC for predicting overall survival (OS) in this study. OS were also analyzed using Kaplan-Meier and Cox regression methods. Based on preoperative CTC and NLR, patients were divided into three groups: CTC-NLR (0), CTC-NLR (1), and CTC-NLR (2). Relationships of CTC-NLR with clinicopathological factors and survival were evaluated.

Results

Preoperatively, CTC positively correlated with NLR. Patients with NLR and CTC higher than the cut-offs had shorter OS than patients with low NLR and CTC. Kaplan-Meier analysis, and log-rank tests revealed significantly lower OS among patients with CTC-NLR scores of 0, 1, and 2. Uni- and multivariate analyses showed that CTC-NLR (hazard ratio 2.050, P = 0.005), CTC (hazard ratio 2.285, P = 0.032), and NLR (hazard ratio 1.902, P = 0.048) were independent predictor of OS. A time-dependent ROC curve indicated that the prognostic efficacy of the CTC-NLR at 1 year (0.714) was better than that of NLR (0.687) and CTC (0.590); the prognostic efficacy of the CTC-NLR at 2 years (0.746) was better than that of NLR (0.711) and CTC (0.601); the prognostic efficacy of the CTC-NLR at 3 years (0.742) was better than that of NLR (0.694) and CTC (0.629).

Conclusions

HCC patients with higher NLR and CTC tend to show shorter OS. Preoperative CTC-NLR may be associated with poor survival and might be a reliable prognostic predictor in HCC after curative hepatectomy.

Recognition of Tumor Nidogen-1 by Neutrophil C-Type Lectin Receptors

Neutrophil-mediated cytotoxicity toward tumor cells requires cell contact and is mediated by hydrogen peroxide. We have recently shown that Cathepsin G expressed on the neutrophil surface interacts with tumor RAGE, and this interaction facilitates neutrophil cytotoxicity. Interruption of the Cathepsin G–RAGE interaction led to 50–80% reduction in cytotoxicity, suggesting that additional interactions are also involved. Here we show that blocking antibodies to the C-type lectin receptors (CLRs) Clec4e and Dectin-1, but not those to NKG2D, attenuated murine neutrophil cytotoxicity towards murine tumor cells, suggesting a contributing role for these CLRs in neutrophil recognition of tumor cells. We further observed that the CLRs interact with tumor Nidogen-1 and Hspg2, two sulfated glycoproteins of the basement membrane. Both Nidogen-1 and Hspg2 were found to be expressed on the tumor cell surface. The knockdown of Nidogen-1, but not that of Hspg2, led to reduced susceptibility of the tumor cells to neutrophil cytotoxicity. Altogether, this study suggests a role for CLR–Nidogen-1 interaction in the recognition of tumor cells by neutrophils, and this interaction facilitates neutrophil-mediated killing of the tumor cells.

Palmatine Attenuates Metastatic Lung Colonization of Triple Negative Breast Cancer Cells

Background: Metastatic breast cancer to the lungs is a serious, life-threatening complication that is difficult to cure. Circulating tumor cells play a key role in the metastatic spread of breast cancer to the lungs via the lymphatic or circulatory system. Palmatine is a protoberberine alkaloid, identified as an active component of traditional African herbal preparations. Palmatine has antimetastatic and antiproliferative effects. The inhibitory activity of palmatine on the metastatic colonization of triple negative breast cancer cells in the lungs was investigated in this study.

Methods: 4T1 triple breast cancer cells were transplanted synergically to the thoracic duct of the female balb/c mice via the lymphatic system. Palmatine 1, 5 and 10 mg/kg were administered for 28 days. The lungs were analyzed for levels of arterial blood gas, histological damage, immunohistochemical expression of the metastasis-associated protein 1 (MTA1) and tumor suppressor p53 (p53).

Results: Administering palmatine 1–10 mg/kg dose dependently improved hypoxemia, ameliorated metastasis associated lung injury; histology score of 3.33 ± 0.33, 1.67 ± 0.33, 1.33 ± 0.33, decreased lung MTA1 (2.19 ± 0.12, 1.83 ± 0.04, 1.84 ± 0.05) and increased p53 expression (1.99 ± 0.06, 2.27 ± 0.12, 2.34 ± 0.12) respectively.

Conclusion: Palmatine preserved lung morphology and demonstrated therapeutic potential in aiding the treatment of lung metastasis.

Translational Strategies to Target Metastatic Bone Disease

Metastatic bone disease is a common and devastating complication to cancer, confounding treatments and recovery efforts and presenting a significant barrier to de-escalating the adverse outcomes associated with disease progression. Despite significant advances in the field, bone metastases remain presently incurable and contribute heavily to cancer-associated morbidity and mortality. Mechanisms associated with metastatic bone disease perpetuation and paralleled disruption of bone remodeling are highlighted to convey how they provide the foundation for therapeutic targets to stem disease escalation. The focus of this review aims to describe the preclinical modeling and diagnostic evaluation of metastatic bone disease as well as discuss the range of therapeutic modalities used clinically and how they may impact skeletal tissue.

Neutrophils as emerging immunotherapeutic targets: Indirect treatment of tumors by regulating the tumor immune environment based on a sialic acid derivative-modified nanocomplex platform

Tumor cells are dependent on their microenvironment; thus, targeting the non-cancerous components surrounding the tumor may be beneficial. Neutrophils are important inflammatory cells in the tumor microenvironment that significantly affect tumor cell proliferation, metastasis, and immune regulation. Targeted regulation of tumor-associated neutrophil-related pathways is expected to become a new therapeutic approach. Colchicine compounds are powerful anti-inflammatory drugs that strongly inhibit the chemotaxis of neutrophils to the inflammatory site. We attempted to achieve anticancer effects by utilizing its ability to inhibit neutrophil recruitment rather than killing tumor cells. As such drugs are likely to cause non-specific damages due to the lack of selectivity, we synthesized and used sialic acid and cholesterol derivatives (SA-CH) for surface modification of the newly synthesized low-toxic colchicine derivative (BCS) nanocomposite to improve neutrophil targeting. In vivo and in vitro experiments have shown that SA-CH-modified BCS preparations are effectively absorbed by neutrophils, inhibit cell migration, reduce infiltration of tumor-associated neutrophils, enhance T lymphocyte function, and exhibit good anti-S180 early tumor effect. In addition, in a triple-negative breast cancer model, the agent could strongly inhibit tumor metastasis to the lungs.

Coordinated Regulation of Myeloid-Derived Suppressor Cells by Cytokines and Chemokines

Simple Summary

In this review, we summarize the effects of various cytokines and chemokines as a network to regulate the expansion, recruitment, and immunosuppressive functions of myeloid-derived suppressor cells in cancer metastasis.

Abstract

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells that impair immune cell functions and promote tumor progression. Mounting evidence indicates that cytokines and chemokines in the tumor microenvironment alter MDSCs. Various cytokines and chemokines are involved in MDSC production, their infiltration into tumors, and their exertion of suppressive functions. Here, we consider those cytokines, chemokines, and MDSCs as an intricately connected, complex system and we focus on how tumors manipulate the MDSCs through various cytokines and chemokines. We also discuss treatment capitalizing on cytokines/chemokine signaling aimed at combating the potent immunosuppressive activities of MDSCs to improve disease outcomes.

Circulating Tumor Cells in Breast Cancer Patients: A Balancing Act between Stemness, EMT Features and DNA Damage Responses

Circulating tumor cells (CTCs) traverse vessels to travel from the primary tumor to distant organs where they adhere, transmigrate, and seed metastases. To cope with these challenges, CTCs have reached maximal flexibility to change their differentiation status, morphology, migratory capacity, and their responses to genotoxic stress caused by metabolic changes, hormones, the inflammatory environment, or cytostatic treatment. A significant percentage of breast cancer cells are defective in homologous recombination repair and other mechanisms that protect the integrity of the replication fork. To prevent cell death caused by broken forks, alternative, mutagenic repair, and bypass pathways are engaged but these increase genomic instability. CTCs, arising from such breast tumors, are endowed with an even larger toolbox of escape mechanisms that can be switched on and off at different stages during their journey according to the stress stimulus. Accumulating evidence suggests that DNA damage responses, DNA repair, and replication are integral parts of a regulatory network orchestrating the plasticity of stemness features and transitions between epithelial and mesenchymal states in CTCs. This review summarizes the published information on these regulatory circuits of relevance for the design of biomarkers reflecting CTC functions in real-time to monitor therapeutic responses and detect evolving chemoresistance mechanisms.

G-CSF and IL-6 may be involved in formation of endometriosis lesions by increasing the expression of angiogenic factors in neutrophils

Evidence accumulated in recent years has revealed that neutrophils are involved in the initial establishment of endometriosis, which is well-known as a chronic inflammatory disease. So far, why and how neutrophils promote the formation of early endometriosis are still unclear. In this study, using a mouse model of endometriosis, we demonstrated that endometriosis mice (EMs mice) had a significantly increased number of neutrophils in peritoneal fluids and lesions, and increased levels of granulocyte colony-stimulating factor (G-CSF) and IL-6 in serum and peritoneal fluids compared to the control group. In the neutrophils and uterine fragments co-injection experiment, neutrophils regulated by G-CSF and IL-6 had a similar effect to neutrophils from EMs mice, increasing the number, area, weight and microvessel density (MVD) of endometriotic lesions. Blocking the effect of G-CSF and IL-6 in EMs mice resulted in a decrease in the number, area and weight of endometriotic lesions. Following the depletion of neutrophils in vivo using a anti-Ly6G antibody, the MVD in the lesions of mice treated with neutrophils from EMs mice and neutrophils from pG/pI6 mice were significantly reduced. Neutrophils from EMs mice and neutrophils from pG/pI6 mice altered the expression levels of Mmp9, Bv8 and Trail genes compared to the neutrophils from PBS-treated mice. IL-6 together with G-CSF induced a higher expression of phospho-STAT3 and STAT3 in neutrophils. These findings suggest that neutrophils modulated by G-CSF and IL-6 through the STAT3 pathway alter the expression levels of the angiogenesis-related genes Mmp9, Bv8 and Trail, and may promote the establishment of early endometriosis.

MMP2 and TLRs modulate immune responses in the tumor microenvironment

The presence of an immunosuppressive tumor microenvironment is a major obstacle in the success of cancer immunotherapies. Because extracellular matrix components can shape the microenvironment, we investigated the role of matrix metalloproteinase 2 (MMP2) in melanoma tumorigenesis. We found that MMP2 signals proinflammatory pathways on antigen presenting cells, and this requires both TLR2 and TLR4. B16 melanoma cells that express MMP2 at baseline have slower kinetics in Tlr2^–/–Tlr4^–/– mice, implicating MMP2 in promoting tumor growth. Indeed, Mmp2 overexpression in B16 cells potentiated rapid tumor growth, which was accompanied by reduced intratumoral cytolytic cells and increased M2 macrophages. In contrast, knockdown of Mmp2 slowed tumor growth and enhanced T cell proliferation and NK cell recruitment. Finally, we found that these effects of MMP2 are mediated through dysfunctional DC–T cell cross-talk as they are lost in Batf3^–/– and Rag2^–/– mice. These findings provide insights into the detrimental role of endogenous alarmins like MMP2 in modulating immune responses in the tumor microenvironment.

Interleukin-37b inhibits the growth of murine endometriosis-like lesions by regulating proliferation, invasion, angiogenesis and inflammation

Endometriosis is a gynecological disease with abnormal expression of interleukin (IL)-37 which can suppress inflammation and the immune system. Here we investigated the role of the IL-37b splice variant in endometriosis in vivo and in vitro. In a murine model of endometriosis, in vivo administration of IL-37b significantly inhibited the development of lesions judged by the number (P = 0.0213), size (P = 0.0130) and weight (P = 0.0152) of lesions. IL-37b had no effect on the early stage of lesion formation, however administration in the growth stage of lesions decreased the number (P = 0.0158), size (P = 0.0158) and weight (P = 0.0258) of lesions compared with PBS control, an effect that was not reversed by macrophage depletion. Expressions of inflammatory factors, matrix metalloproteinases and vascular endothelial growth factor-A mRNA/protein were significantly inhibited in ectopic lesions following IL-37b administration, and in uterine segments treated in vitro. In vitro treatment of uterine segments with IL-37b inhibited phosphorylation of Akt and Erk1/2 in uterine segments. Isolated mouse endometrial stromal treated with IL-37b and transfected with pIL-37b plasmid got suppressed cell proliferation, invasion, angiogenesis and the expression of inflammatory factors. In addition, transfection with pIL-37b significantly decreased the phosphorylation of Akt and Erk1/2. IL-37b also inhibited proliferation and the expression of inflammatory and angiogenesis factors in epithelial cell line RL95-2. These findings suggest that IL-37b may inhibit the growth of lesions by regulating proliferation, invasion, angiogenesis and inflammation through Akt and Erk1/2 signaling pathway.

The association of the neutrophil-lymphocyte ratio with the presence of minimal residual disease and outcome in patients with Stage II colon cancer treated with surgery alone

AIM

Despite curative surgery, 25% of patients with Stage II colorectal cancer will relapse due to minimal residual disease (MRD). Markers of immune function, such as the neutrophil to lymphocyte ratio (NLR), may be associated with MRD defined by bone marrow micro-metastasis (mM) and circulating tumour cells (CTCs).

METHOD

A prospective cohort study of consecutive patients with Stage II colon cancer patients attended at a single centre between 2007 and 2014. Blood and bone marrow samples were taken to detect CTCs and mM using immunocytochemistry with anti-carcinoembryonic antigen 1 month after surgery. The NLR and absolute neutrophil and lymphocyte counts were determined immediately pre-surgery and 1 month post-surgery. These were compared with the sub-types of MRD: group I MRD(-); group II mM positive and group III CTC positive. Cut-off values of the NLR of >3.0 and >5.0 were used. Follow-up was for up to 5 years or relapse and disease-free survival (DFS) was calculated using Kaplan-Meier analysis.

RESULTS

In all, 181 patients (99 women) participated. Mean age was 68 years. Median follow-up was 4.04 years: I, N = 105; II, N = 36; III, N = 40. The NLR significantly decreased post-surgery only in group I patients. The frequency of NLR >3.0 and >5.0 was significantly higher in group III; between groups I and II there was no significant difference. 5-year DFS was 98% in group I, 68% in group II and 7% in group III.

CONCLUSIONS

Patients with a significantly higher immune dysfunction had a shorter time to disease progression, a worse DFS and the presence of CTCs.

Pretreatment neutrophil-to-lymphocyte ratio and mutational burden as biomarkers of tumor response to immune checkpoint inhibitors

Treatment with immune checkpoint inhibitors (ICI) has demonstrated clinical benefit for a wide range of cancer types. Because only a subset of patients experience clinical benefit, there is a strong need for biomarkers that are easily accessible across diverse practice settings. Here, in a retrospective cohort study of 1714 patients with 16 different cancer types treated with ICI, we show that higher neutrophil-to-lymphocyte ratio (NLR) is significantly associated with poorer overall and progression-free survival, and lower rates of response and clinical benefit, after ICI therapy across multiple cancer types. Combining NLR with tumor mutational burden (TMB), the probability of benefit from ICI is significantly higher (OR = 3.22; 95% CI, 2.26-4.58; P < 0.001) in the NLR low/TMB high group compared to the NLR high/TMB low group. NLR is a suitable candidate for a cost-effective and widely accessible biomarker, and can be combined with TMB for additional predictive capacity.

There is an unmet clinical need for simple, accessible biomarkers to select patients who are more likely to respond to immune checkpoint therapy. Here the authors show that a lower neutrophil-to-lymphocyte ratio is associated with better overall and progressive-free survival, as well as higher rate of response, in a multi-cancer cohort of patients treated with immune checkpoint inhibitors.

The Influence of Tumor Microenvironment on Immune Escape of Melanoma

The low efficiency of currently-used anti-cancer therapies poses a serious challenge, especially in the case of malignant melanoma, a cancer characterized by elevated invasiveness and relatively high mortality rate. The role of the tumor microenvironment in the progression of melanoma and its acquisition of resistance to treatment seems to be the main focus of recent studies. One of the factors that, in normal conditions, aids the organism in its fight against the cancer and, following the malignant transformation, adapts to facilitate the development of the tumor is the immune system. A variety of cell types, i.e., T and B lymphocytes, macrophages, and dendritic and natural killer cells, as well as neutrophils, support the growth and invasiveness of melanoma cells, utilizing a plethora of mechanisms, including secretion of pro-inflammatory molecules, induction of inhibitory receptors expression, or depletion of essential nutrients. This review provides a comprehensive summary of the processes regulated by tumor-associated cells that promote the immune escape of melanoma cells. The described mechanisms offer potential new targets for anti-cancer treatment and should be further studied to improve currently-employed therapies.

Nodal characteristics associated with adverse prognosis in oral cavity cancer are linked to host immune status

BACKGROUND AND OBJECTIVE

Nodal metastasis is one of the strongest predictors of outcomes in oral cavity squamous cell carcinomas (OSCC). The aim was to analyze the interplay of nodal characteristics in OSCC prognosis.

METHODS

In this retrospective cohort study we included OSCC patients treated with primary surgery including neck dissection between 2005 and 2015 (n = 619). Disease-specific survival (DSS) was the primary endpoint. Optimal cutoffs were identified using recursive-partitioning analysis (RPA). A novel characteristic-metastatic focus-to-lymph node size ratio (MLR)-was introduced. We compared the American Joint Committee on Cancer, Eighth Edition (AJCC8) pN categories to a new categorization.

RESULTS

Patients with higher neutrophil-to-lymphocyte ratio had more adverse nodal characteristics. All nodal characteristics were significant predictors of DSS in univariable analysis. In multivariable analysis, only number of positive nodes and MLR remained significant. An RPA including all nodal covariates confirmed the results. Compared with AJCC8, our RPA categorization had better hazard discrimination (0.681 vs. 0.598), but poorer balance value (0.783 vs. 0.708).

CONCLUSION

Patients with higher neutrophil-to-lymphocyte ratio had more adverse nodal characteristics. Total number of metastatic lymph nodes is the strongest predictor of outcomes in OSCC. MLR is a more powerful predictor than metastatic lymph node size or metastatic focus size alone.

Neutrophils: Accomplices in metastasis

Metastasis is a critical cause of treatment failure and death in patients with advanced malignancies. Tumor cells can leave the primary site and enter the bloodstream; these circulating tumor cells then colonize target organs by overcoming blood shear stress, evading immune surveillance, and silencing the offensive capabilities of immune cells, eventually forming metastatic foci. From leaving the primary focus to the completion of distant metastasis, malignant tumor cells are supported and/or antagonized by certain immune cells. In particular, it has been found that myeloid granulocytes play an important role in this process. This review therefore aims to comprehensively describe the significance of neutrophils in solid tumor metastasis in terms of their supporting role in initiating the invasion and migration of tumor cells and assisting the colonization of circulating tumor cells in distant target organs, with the hope of providing insight into and ideas for anti-tumor metastasis treatment of tumor patients.

Cancer stem cell property and gene signature in bone-metastatic Breast Cancer cells

The majority of the deaths from breast cancer is due to metastasis. Bone is the most common organ to which breast cancer cells metastasize. The mechanism regulating the bone-metastatic preference remains unclear; there is a lack of a gene signature to distinguish bone-metastatic breast cancer cells. Herein, florescence-labeled MDA-MB-231 cells were transplanted into the fat pads of of the mammary gland in nude mice to generate breast tumors. Tumor cells invaded into the circulation were tracked by in vivo flow cytometry system. Metastatic tumor cells in the bone were isolated using fluorescent-activated cell sorting technique, followed by assays of cell colony formation, migration and invasion, mammosphere formation in vitro, mammary gland tumorigenesis in vivo, and Next-Generation Sequencing analysis as well. Through tumor regeneration and cell sorting, two bone-metastatic cell sublines were derived from MDA-MB-231 cells; which showed higher abilities to proliferate, migrate, invade and epithelial-to-mesenchymal transit in vitro, and stronger ability to regenerate tumors and metastasize to the bone in vivo. Both cell sublines exhibited cancer stem cell-like characteristics including higher expression levels of stem cell markers and stronger ability for mommaspheres formation. Furthermore, a Normal Distribution-like pattern of the bone-metastatic cells invading into circulation was firstly identified. Deep-sequencing analysis indicated upregulation of multiple signaling pathways in regulating EMT, cell membrane budding and morphologic change, lipid metabolism, and protein translation, which are required to provide adequate metabolic enzymes, structural proteins, and energy for the cells undergoing metastasis. In conclusion, we established two bone-metastatic breast cancer cell sublines, carrying higher degree of stemness and malignancy. The gene signature distinguishing the bone-metastatic breast cancer cells holds therapeutic potentials in prevention of breast cancer metastasis to the bone.

Quantification of Protein Secretion from Circulating Tumor Cells in Microfluidic Chambers

Cancer cells can be released from a cancerous lesion and migrate into the circulatory system, from whereon they may form metastases at distant sites. Today, it is possible to infer cancer progression and treatment efficacy by determining the number of circulating tumor cells (CTCs) in the patient's blood at multiple time points; further valuable information about CTC phenotypes remains inaccessible. In this article, a microfluidic method for integrated capture, isolation, and analysis of membrane markers as well as quantification of proteins secreted by single CTCs and CTC clusters is introduced. CTCs are isolated from whole blood with extraordinary efficiencies above 95% using dedicated trapping structures that allow co-capture of functionalized magnetic beads to assess protein secretion. The patform is tested with multiple breast cancer cell lines spiked into human blood and mouse-model-derived CTCs. In addition to immunostaining, the secretion level of granulocyte growth stimulating factor (G-CSF), which is shown to be involved in neutrophil recruitment, is quantified The bead-based assay provides a limit of detection of 1.5 ng mL^-1 or less than 3700 molecules per cell. Employing barcoded magnetic beads, this platform can be adapted for multiplexed analysis and can enable comprehensive functional CTC profiling in the future.

Hepatocytes paradoxically affect intrahepatic IFN-γ production in autoimmune hepatitis due to Gal-9 expression and TLR2/4 ligand release

Hepatocytes are the targets in autoimmune hepatitis (AIH) that results in T cell-dependent liver injury. However, hepatocytes may also affect the hepatic T cells in AIH, but the underlying mechanisms are not fully understood. Here we report that hepatocytes could secrete galectin-9 (Gal-9) to suppress the intrahepatic production of Th1 cytokine IFN-γ and restrict AIH development, but hepatocyte damage resulted in opposite effects due to release of TLR2/4 ligands that promoted the intrahepatic production of IL-1β, IL-6, and IL-12. Through Tim-3, Gal-9 could efficiently suppress the intrahepatic T cell activation despite presence of TLR2/4 ligands, thus attenuating Th1 response in AIH. Intriguingly, intrahepatic IL-6/IL-12 suppressed the effect of TGF-β on Treg cells. Therefore, in AIH, Gal-9 promoted Foxp3 expression and function of hepatic Treg cells through TL1A signaling, although Treg function was still impaired, compared with that in naive state. Due to its promoting effect on Treg function, together with its effect on T effector cells in a Tim-3-independent way, Gal-9 could attenuate intrahepatic IFN-γ production by hindering the increase of hepatic CD4⁺CD43⁺ T cells resulting from extrahepatic T cell activation. TLR2/4 ligands attenuated the effects of Gal-9 on Treg cells and CD4⁺CD43⁺ T cells by increasing intrahepatic IL-6 and IL-12. Blocking TLR2/4 ligands could efficiently suppress intrahepatic IFN-γ production, liver injury, and hepatic fibrosis. These findings suggest that hepatocytes paradoxically affect Th1 response in AIH due to Gal-9 expression and TLR2/4 ligands release, and that targeting TLR2/4 signaling may provide an important approach in the therapeutic strategy for AIH.

Serum proteomic analysis of melanoma patients with immunohistochemical profiling of primary melanomas and cultured cells: Pilot study

The steadily increasing incidence of malignant melanoma (MM) and its aggressive behaviour makes this tumour an attractive cancer research topic. The tumour microenvironment is being increasingly recognised as a key factor in cancer biology, with an impact on proliferation, invasion, angiogenesis and metastatic spread, as well as acquired therapy resistance. Multiple bioactive molecules playing cooperative roles promote the chronic inflammatory milieu in tumours, making inflammation a hallmark of cancer. This specific inflammatory setting is evident in the affected tissue. However, certain mediators can leak into the systemic circulation and affect the whole organism. The present study analysed the complex inflammatory response in the sera of patients with MM of various stages. Multiplexed proteomic analysis (Luminex Corporation) of 31 serum proteins was employed. These targets were observed in immunohistochemical profiles of primary tumours from the same patients. Furthermore, these proteins were analysed in MM cell lines and the principal cell population of the melanoma microenvironment, cancer‑associated fibroblasts. Growth factors such as hepatocyte growth factor, granulocyte‑colony stimulating factor and vascular endothelial growth factor, chemokines RANTES and interleukin (IL)‑8, and cytokines IL‑6, interferon‑α and IL‑1 receptor antagonist significantly differed in these patients compared with the healthy controls. Taken together, the results presented here depict the inflammatory landscape that is altered in melanoma patients, and highlight potentially relevant targets for therapy improvement.

Unraveling the crosstalk between melanoma and immune cells in the tumor microenvironment

Cutaneous melanoma is the most common skin cancer with an incidence that has been rapidly increasing in the past decades. Melanomas are among the most immunogenic tumors and, as such, have the greatest potential to respond favorably to immunotherapy. However, like many cancers, melanomas acquire various suppressive mechanisms, which generally act in concert, to escape innate and adaptive immune detection and destruction. Intense research into the cellular and molecular events associated with melanomagenesis, which ultimately lead to immune suppression, has resulted in the discovery of new therapeutic targets and synergistic combinations of immunotherapy, targeted therapy and chemotherapy. Tremendous effort to determine efficacy of single and combination therapies in pre-clinical and clinical phase I-III trials has led to FDA-approval of several immunotherapeutic agents that could potentially be beneficial for aggressive, highly refractory, advanced and metastatic melanomas. The increasing availability of approved combination therapies for melanoma and more rapid assessment of patient tumors has increased the feasibility of personalized treatment to overcome patient and tumor heterogeneity and to achieve greater clinical benefit. Here, we review the evolution of the immune system during melanomagenesis, mechanisms exploited by melanoma to suppress anti-tumor immunity and methods that have been developed to restore immunity. We emphasize that an effective therapeutic strategy will require coordinate activation of tumor-specific immunity as well as increased recognition and accessibility of melanoma cells in primary tumors and distal metastases. This review integrates available knowledge on melanoma-specific immunity, molecular signaling pathways and molecular targeting strategies that could be utilized to envision therapeutics with broader application and greater efficacy for early stage and advanced metastatic melanoma.

The biology and clinical potential of circulating tumor cells

Background

Tumor cells can shed from the tumor, enter the circulation and travel to distant organs, where they can seed metastases. These cells are called circulating tumor cells (CTCs). The ability of CTCs to populate distant tissues and organs has led us to believe they are the primary cause of cancer metastasis. The biological properties and interaction of CTCs with other cell types during intravasation, circulation in the bloodstream, extravasation and colonization are multifaceted and include changes of CTC phenotypes that are regulated by many signaling molecules, including cytokines and chemokines. Considering a sample is readily accessible by a simple blood draw, monitoring CTC levels in the blood has exceptional implications in oncology field. A method called the liquid biopsy allows the extraction of not only CTC, but also CTC products, such as cell free DNA (cfDNA), cell free RNA (cfRNA), microRNA (miRNA) and exosomes.

Conclusions

The clinical utility of CTCs and their products is increasing with advances in liquid biopsy technology. Clinical applications of liquid biopsy to detect CTCs and their products are numerous and could be used for screening of the presence of the cancer in the general population, as well as for prognostic and predictive biomarkers in cancer patients. With the development of better CTC isolation technologies and clinical testing in large prospective trials, increasing clinical utility of CTCs can be expected. The understanding of their biology and interactions with other cell types, particularly with those of the immune system and the rise of immunotherapy also hold great promise for novel therapeutic possibilities.

TLR2/4 ligand-amplified liver inflammation promotes initiation of autoimmune hepatitis due to sustained IL-6/IL-12/IL-4/IL-25 expression

Autoimmune hepatitis (AIH), a serious autoimmune liver disease, can be a lifelong illness, leading to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). So far the mechanisms for disease initiation are largely unknown. Here we report that the amplified non-AIH liver inflammation could promote the initiation of AIH due to the sustained increase of IL-6, IL-12, IL-4, and IL-25 in the liver. The liver injury resulting from virus (adenovirus) or chemicals (CCl₄) could induce an amplified (stronger/long-lasting) hepatic inflammation by releasing the ligands for TLR2/TLR4. The amplified inflammation resulted in the increase of multiple cytokines and chemokines in the liver. Among them, the sustained increase of IL-6/IL-12 resulted in the activation of STAT3 and STAT4 in hepatic CD4⁺CD25⁺ Treg cells, thus suppressing Foxp3 gene expression to reduce the suppressive function of Treg cells in the liver, but not those in the spleen. The increase of IL-12 and the impairment of Treg function promoted Th1 response in presence of self-mimicking antigen (human CYP2D6). Intriguingly, the amplified inflammation resulted in the increase of IL-4 and IL-25 in the liver. The moderate increase of IL-4 was sufficient for cooperating with IL-25 to initiate Th2 response, but inefficient in suppressing Th1 response, favoring the initiation of autoimmune response. Consequently, either adenovirus/CYP2D6 or CCl₄/CYP2D6 could induce the autoimmune response and AIH in the mice, leading to hepatic fibrosis. The findings in this study suggest that the amplified non-AIH inflammation in the liver could be a driving force for the initiation of autoimmune response and AIH.