Chemokines induce migrational responses in human breast carcinoma cell lines

Current progress in chimeric antigen receptor-modified T cells for the treatment of metastatic breast cancer

Breast cancer is the leading cancer in women. Around 20-30% breast cancer patients undergo invasion or metastasis after radical surgical resection and eventually die. Number of breast cancer patients show poor sensitivity toward treatments despite the advances in chemotherapy, endocrine therapy, and molecular targeted treatments. Therapeutic resistance and tumor recurrence or metastasis develop with the ongoing treatments. Conducive treatment strategies are thus required. Chimeric antigen receptor (CAR)-modified T-cell therapy has progressed as a part of tumor immunotherapy. However, CAR-T treatment has not been effective in solid tumors because of tumor microenvironment complexity, inhibitory effects of extracellular matrix, and lacking ideal tumor antigens. Herein, the prospects of CAR-T cell therapy for metastatic breast cancer are discussed, and the targets for CAR-T therapy in breast cancer (HER-2, C-MET, MSLN, CEA, MUC1, ROR1, EGFR) at clinical level are reviewed. Moreover, solutions are proposed for the challenges of breast cancer CAR-T therapy regarding off-target effects, heterogeneous antigen expression by tumor cells and immunosuppressive tumor microenvironment. Ideas for improving the therapeutics of CAR-T cell therapy in metastatic breast cancer are suggested.

The chemokine monocyte chemoattractant protein-1/CCL2 is a promoter of breast cancer metastasis

Breast cancer is the most prevalent cancer worldwide, and metastasis is the leading cause of death in cancer patients. Human monocyte chemoattractant protein-1 (MCP-1/CCL2) was isolated from the culture supernatants of not only mitogen-activated peripheral blood mononuclear leukocytes but also malignant glioma cells based on its in vitro chemotactic activity toward human monocytes. MCP-1 was subsequently found to be identical to a previously described tumor cell-derived chemotactic factor thought to be responsible for the accumulation of tumor-associated macrophages (TAMs), and it became a candidate target of clinical intervention; however, the role of TAMs in cancer development was still controversial at the time of the discovery of MCP-1. The in vivo role of MCP-1 in cancer progression was first evaluated by examining human cancer tissues, including breast cancers. Positive correlations between the level of MCP-1 production in tumors and the degree of TAM infiltration and cancer progression were established. The contribution of MCP-1 to the growth of primary tumors and metastasis to the lung, bone, and brain was examined in mouse breast cancer models. The results of these studies strongly suggested that MCP-1 is a promoter of breast cancer metastasis to the lung and brain but not bone. Potential mechanisms of MCP-1 production in the breast cancer microenvironment have also been reported. In the present manuscript, we review studies in which the role of MCP-1 in breast cancer development and progression and the mechanisms of its production were examined and attempt to draw a consensus and discuss the potential use of MCP-1 as a biomarker for diagnosis.

Involvement in Tumorigenesis and Clinical Significance of CXCL1 in Reproductive Cancers: Breast Cancer, Cervical Cancer, Endometrial Cancer, Ovarian Cancer and Prostate Cancer

C-X-C motif chemokine ligand 1 (CXCL1) is a member of the CXC chemokine subfamily and a ligand for CXCR2. Its main function in the immune system is the chemoattraction of neutrophils. However, there is a lack of comprehensive reviews summarizing the significance of CXCL1 in cancer processes. To fill this gap, this work describes the clinical significance and participation of CXCL1 in cancer processes in the most important reproductive cancers: breast cancer, cervical cancer, endometrial cancer, ovarian cancer, and prostate cancer. The focus is on both clinical aspects and the significance of CXCL1 in molecular cancer processes. We describe the association of CXCL1 with clinical features of tumors, including prognosis, ER, PR and HER2 status, and TNM stage. We present the molecular contribution of CXCL1 to chemoresistance and radioresistance in selected tumors and its influence on the proliferation, migration, and invasion of tumor cells. Additionally, we present the impact of CXCL1 on the microenvironment of reproductive cancers, including its effect on angiogenesis, recruitment, and function of cancer-associated cells (macrophages, neutrophils, MDSC, and T_reg). The article concludes by summarizing the significance of introducing drugs targeting CXCL1. This paper also discusses the significance of ACKR1/DARC in reproductive cancers.

Curcumin and chemokines: mechanism of action and therapeutic potential in inflammatory diseases

Chemokines belong to the family of cytokines with chemoattractant properties that regulate chemotaxis and leukocyte migration, as well as the induction of angiogenesis and maintenance of hemostasis. Curcumin, the major component of the Curcuma longa rhizome, has various pharmacological actions, including anti-inflammatory, immune-regulatory, anti-oxidative, and lipid-modifying properties. Chemokines and chemokine receptors are influenced/modulated by curcumin. Thus, the current review focuses on the molecular mechanisms associated with curcumin's effects on chemoattractant cytokines, as well as putting into context the many studies that have reported curcumin-mediated regulatory effects on inflammatory conditions in the organs/systems of the body (e.g., the central nervous system, liver, and cardiovascular system). Curcumin's effects on viral and bacterial infections, cancer, and adverse pregnancy outcomes are also reviewed.

Baseline Cytokine Profile Identifies a Favorable Outcome in a Subgroup of Colorectal Cancer Patients Treated with Regorafenib

Metastatic colorectal cancer is frequently associated with poor clinical conditions that may limit therapeutic options. Regorafenib is a small molecule approved for the treatment of metastatic colorectal cancer, but it is hampered by significative toxicities. Moreover, only a relatively limited number of patients benefit from the treatment. Therefore, the identification of reliable markers for response is an unmet need. Eighteen cytokines, selected based on their prevalent Th1 or Th2 effects, were collected. Peripheral blood samples were gathered at baseline in 25 metastatic colorectal cancer patients treated with regorafenib. Data extracted have been linked to progression-free survival. ROC identified the best cytokines associated with outcome. The relative value of the selected cytokines was determined by PCA. Data analysis identified 8 cytokines (TGF-β, TNF-α, CCL-2, IL-6, IL-8, IL-10, IL-13 and IL-21), used to create a signature (TGF-β, TNF-α high; CCL-2, IL-6, IL-8, IL-10, IL-13 and IL-21 low) corresponding to patients with a significantly longer progression-free survival. This report suggests that the analysis of multiple cytokines might identify a cytokine signature related to a patient's outcome that is able to recognize patients who will benefit from treatment. If confirmed, future studies, also based on different drugs, using this approach and including larger patient populations, might identify a signature allowing the a priori identification of patients to be treated.

Novel secretion modification region (SMR) peptide exhibits anti-metastatic properties in human breast cancer cells

Breast cancer is the second leading cause of cancer-related mortality in women worldwide, with nearly 90% attributed to metastatic progression. Exosomes containing epithelial–mesenchymal transition (EMT) ‘programs’ transmit pro-metastatic phenotypes. Our group discovered and developed a novel anti-cancer SMR peptide that antagonizes breast cancer cell exosome release resulting in cell cycle arrest and tumor growth suppression. This study aims to evaluate the anti-metastatic capabilities of the SMR peptide, focusing on exosomes and EMT. Breast cancer cell lines MDA-MB-231 and MCF-7 were treated with the SMRwt peptide, and the following assays were performed: cell wound-healing, migration, invasion. The SMRwt peptide consists of the following amino acid sequence VGFPVAAVGFPVDYKDDDDK and contains the SMR domain (⁶⁶VGFPV⁷⁰) of the HIV-1 Nef protein. Western blot analysis detected epithelial and mesenchymal markers to evaluate EMT progression. Extracellular vesicle type and quantity were assessed through NanoSight analysis. Mortalin and Vimentin knockdown was achieved through antibody targeting and miRNAs. Data gathered demonstrated that the SMR peptide interacts with Mortalin and Vimentin to inhibit pro-EMT exosome release and induce EMT tumor suppressor protein expression. Specifically, SMRwt treatment reduced mesenchymal markers Mortalin and Vimentin expression, while the epithelial marker E-cadherin expression was increased in breast cancer cells and breast cancer-derived exosomes. The SMR peptide specificity was identified as no effect was observed for MCF-10A exosome release or function. Direct Mortalin knockdown paralleled the results of SMR peptide treatment with an effective blockade of breast cancer cell migration. Conversely, the invasion assay differed between breast cancer cell lines with invasion blocked for in MCF-7 but not in MDA-MB-231. These results reinforce the therapeutic value of targeting breast cancer exosome release and reinforce Mortalin and Vimentin as critical regulators and therapeutic targets in breast cancer cell progression, EMT, and metastatic potential. A greater understanding of the SMR peptide mechanism of action will benefit the therapeutic design of anti-metastatic agents.

Role of chemokines in breast cancer

Chemokines belong to a family of chemoattractant cytokines and are well known to have an essential role in various cancer aetiologies. Multiplesubsets of immune cells are recruited and enrolled into the tumor microenvironment through interactions between chemokines and their specific receptors. These populations and their interactions have a distinct impact on tumor growth, progression, and treatment outcomes. While it is clear that many chemokines and their cognate receptors can be detected in breast and other cancers, the role of each chemokine and receptor has yet to be determined. This review focuses on the main chemokines that play a crucial role in the tumor microenvironment, emphasizing breast cancer. We have also discussed the techniques used to identify the chemokines and their future implication in the early diagnosis of cancer. In-depth knowledge of chemokines and their role in breast cancer progression can provide specific targets for breast cancer biotherapy.

The Impact of Esophageal Oncological Surgery on Perioperative Immune Function; Implications for Adjuvant Immune Checkpoint Inhibition

Background

Immune checkpoint inhibitors (ICIs) are being investigated for their role as an adjunct in the multimodal treatment of esophageal adenocarcinoma (EAC). The most effective time to incorporate ICIs remains unknown. Our study profiles systemic anti-tumor immunity perioperatively to help inform the optimal timing of ICIs into current standards of care for EAC patients.

Methods

Systemic immunity in 11 EAC patients was phenotyped immediately prior to esophagectomy (POD-0) and post-operatively (POD)-1, 3, 7 and week 6. Longitudinal serological profiling was conducted by ELISA. The frequency of circulating lymphocytes, activation status, immune checkpoint expression and damage-associated molecular patterns was assessed by flow cytometry.

Results

The frequency of naïve T-cells significantly increased in circulation post-esophagectomy from POD-0 to POD-7 (p<0.01) with a significant decrease in effector memory T-cells by POD7 followed by a subsequent increase by week 6 (p<0.05). A significant increase in activated circulating CD27⁺ T-cells was observed from POD-0 to POD-7 (p<0.05). The percentage of PD-1⁺ and CTLA-4⁺ T-cells peaked on POD-1 and was significantly decreased by week 6 (p<0.01). There was a significant increase in soluble PD-1, PD-L2, TIGIT and LAG-3 from POD-3 to week 6 (p<0.01). Increased checkpoint expression correlated with those who developed metastatic disease early in their postoperative course. Th1 cytokines and co-stimulatory factors decreased significantly in the immediate post-operative setting, with a reduction in IFN-γ, IL-12p40, IL-1RA, CD28, CD40L and TNF-α. A simultaneous increase was observed in Th2 cytokines in the immediate post-operative setting, with a significant increase in IL-4, IL-10, IL-16 and MCP-1 before returning to preoperative levels at week 6.

Conclusion

Our study highlights the prevailing Th2-like immunophenotype post-surgery. Therefore, shifting the balance in favour of a Th1-like phenotype would offer a potent therapeutic approach to promote cancer regression and prevent recurrence in the adjuvant setting and could potentially propagate anti-tumour immune responses perioperatively if administered in the immediate neoadjuvant setting. Consequently, this body of work paves the way for further studies and appropriate trial design is needed to further interrogate and validate the use of ICI in the multimodal treatment of locally advanced disease in the neoadjuvant and adjuvant setting.

O-GlcNAcylation of Blimp-1 in lymphocytes inhibits its transcriptional function and is associated with migration and invasion of breast cancer cells

Lymphocyte infiltration is an important feature of cancer. There is a complex network of chemokines that influence the degree and phenotype of lymphocyte infiltration, as well as the growth, survival, migration and angiogenesis of tumor cells. High heterogeneity metastasis is a major obstacle to the treatment of breast cancer. Herein, we showed that O-GlcNAcylation of B lymphocyte-induced maturation protein-1 (Blimp-1) in lymphocytes inhibited the migration and invasion of breast cancer cells. It was found that Blimp-1 O-GlcNAcylation at Ser448 and Ser472 in lymphocytes promoted its nuclear localization, and blocked the bindings to three regions upstream of the ccl3l1 promoter to inhibit its expression. Decreased expression of CCL3L1 in lymphocytes not only decreased CCR5 expression in breast cancer cells, but also inhibited the membrane localization and activation of CCR5, thus blocking the migration and invasion of breast cancer cells in vitro. Therefore, O-GlcNAcylation of Blimp-1 in lymphocytes may serve as a new target for the treatment of metastatic breast cancer. Implications: This study reveals a new mechanism by which the lymphatic system promotes breast cancer cell metastasis.

Chemokines orchestrate tumor cells and the microenvironment to achieve metastatic heterogeneity

Chemokines, a subfamily of the cell cytokines, are low molecular weight proteins known to induce chemotaxis in leukocytes in response to inflammatory and pathogenic signals. A plethora of literature demonstrates that chemokines and their receptors regulate tumor progression and metastasis. With these diverse functionalities, chemokines act as a fundamental link between the tumor cells and their microenvironment. Recent studies demonstrate that the biology of chemokines and their receptor in metastasis is complex as numerous chemokines are involved in regulating site-specific tumor growth and metastasis. Successful treatment of disseminated cancer is a significant challenge. The most crucial problem for treating metastatic cancer is developing therapy regimes capable of overcoming heterogeneity problems within primary tumors and among metastases and within metastases (intralesional). This heterogeneity of malignant tumor cells can be related to metastatic potential, response to chemotherapy or specific immunotherapy, and many other factors. In this review, we have emphasized the role of chemokines in the process of metastasis and metastatic heterogeneity. Individual chemokines may not express the full potential to address metastatic heterogeneity, but chemokine networks need exploration. Understanding the interplay between chemokine-chemokine receptor networks between the tumor cells and their microenvironment is a novel approach to overcome the problem of metastatic heterogeneity. Recent advances in the understanding of chemokine networks pave the way for developing a potential targeted therapeutic strategy to treat metastatic cancer.

The multifaceted roles of the chemokines CCL2 and CXCL12 in osteophilic metastatic cancers

Breast and prostate cancers have a great propensity to metastasize to long bones. The development of bone metastases is life-threatening, incurable, and drastically reduces patients' quality of life. The chemokines CCL2 and CXCL12 and their respective receptors, CCR2 and CXCR4, are central instigators involved in all stages leading to cancer cell dissemination and secondary tumor formation in distant target organs. They orchestrate tumor cell survival, growth and migration, tumor invasion and angiogenesis, and the formation of micrometastases in the bone marrow. The bone niche is of particular importance in metastasis formation, as it expresses high levels of CCL2 and CXCL12, which attract tumor cells and contribute to malignancy. The limited number of available effective treatment strategies highlights the need to better understand the pathophysiology of bone metastases and reduce the skeletal tumor burden in patients diagnosed with metastatic bone disease. This review focuses on the involvement of the CCL2/CCR2 and CXCL12/CXCR4 chemokine axes in the formation and development of bone metastases, as well as on therapeutic perspectives aimed at targeting these chemokine-receptor pairs.

Tackling Immune Targets for Breast Cancer: Beyond PD-1/PD-L1 Axis

The burden of breast cancer is imposing a huge global problem. Drug discovery research and novel approaches to treat breast cancer have been carried out extensively over the last decades. Although immune checkpoint inhibitors are showing promising preclinical and clinical results in treating breast cancer, they are facing multiple limitations. From an immunological perspective, a recent report highlighted breast cancer as an "inflamed tumor" with an immunosuppressive microenvironment. Consequently, researchers have been focusing on identifying novel immunological targets that can tune up the tumor immune microenvironment. In this context, several novel non-classical immune targets have been targeted to determine their ability to uncouple immunoregulatory pathways at play in the tumor microenvironment. This article will highlight strategies designed to increase the immunogenicity of the breast tumor microenvironment. It also addresses the latest studies on targets which can enhance immune responses to breast cancer and discusses examples of preclinical and clinical trial landscapes that utilize these targets.

Research trends in pharmacological modulation of tumor-associated macrophages

As one of the most abundant immune cell populations in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play important roles in multiple solid malignancies, including breast cancer, prostate cancer, liver cancer, lung cancer, ovarian cancer, gastric cancer, pancreatic cancer, and colorectal cancer. TAMs could contribute to carcinogenesis, neoangiogenesis, immune-suppressive TME remodeling, cancer chemoresistance, recurrence, and metastasis. Therefore, reprogramming of the immune-suppressive TAMs by pharmacological approaches has attracted considerable research attention in recent years. In this review, the promising pharmaceutical targets, as well as the existing modulatory strategies of TAMs were summarized. The chemokine-chemokine receptor signaling, tyrosine kinase receptor signaling, metabolic signaling, and exosomal signaling have been highlighted in determining the biological functions of TAMs. Besides, both preclinical research and clinical trials have suggested the chemokine-chemokine receptor blockers, tyrosine kinase inhibitors, bisphosphonates, as well as the exosomal or nanoparticle-based targeting delivery systems as the promising pharmacological approaches for TAMs deletion or reprogramming. Lastly, the combined therapies of TAMs-targeting strategies with traditional treatments or immunotherapies as well as the exosome-like nanovesicles for cancer therapy are prospected.

Analysis of the Gene Expression Profile of Stromal Pro-Tumor Factors in Cancer-Associated Fibroblasts from Luminal Breast Carcinomas

Luminal tumors are the most frequent type of breast carcinomas showing less tumor aggressiveness, although heterogeneity exists in their clinical outcomes. Cancer-associated fibroblasts (CAFs) are a key component of the tumor stroma which contribute to tumor progression. We investigated by real-time PCR the gene expression of 19 factors implicated in tumor progression. Those factors included the calcium-binding protein S100A4, several growth factors (FGF2, FGF7, HGF, PDGFA, PDGFB, TGFβ, VEGFA, and IGF2), and we also studied inflammatory cytokines (IL6 and IL8), chemokines (CCL2, CXCL12), important proteases (uPA, MMP2, MMP9 and MMP11), the nuclear factor NFκB, and the metalloprotease inhibitor TIMP1, from luminal A and luminal B breast carcinoma CAFs. We performed a similar analysis after co-culturing CAFs with MCF-7 and MDA-MB-231 breast cancer cell lines. MMP-9 and CCL2 gene expressions were higher in CAFs from luminal B tumors. We also found different patterns in the induction of pro-tumoral factors from different CAFs populations co-cultured with different cancer cell lines. Globally, CAFs from luminal B tumors showed a higher expression of pro-tumor factors compared to CAFs from luminal A tumors when co-cultured with breast cancer cell lines. Moreover, we found that CAFs from metastatic tumors had higher IGF-2 gene expression, and we detected the same after co-culture with cell lines. Our results show the variability in the capacities of CAFs from luminal breast carcinomas, which may contribute to a better biological and clinical characterization of these cancer subtypes.

Chemokines in bone-metastatic breast cancer: Therapeutic opportunities

Due to non-response to chemotherapy, incomplete surgical resection, and resistance to checkpoint inhibitors, breast cancer with bone metastasis is notoriously difficult to cure. Therefore, the development of novel, efficient strategies to tackle bone metastasis of breast cancer is urgently needed. Chemokines, which induce directed migration of immune cells and act as guide molecules between diverse cells and tissues, are small proteins indispensable in immunity. These complex chemokine networks play pro-tumor roles or anti-tumor roles when produced by breast cancer cells in the tumor microenvironment. Additionally, chemokines have diverse roles when secreted by various immune cells in the tumor microenvironment of breast cancer, which can be roughly divided into immunosuppressive effects and immunostimulatory effects. Recently, targeting chemokine networks has been shown to have potential for use in treatment of metastatic malignancies, including bone-metastatic breast cancer. In this review, we focus on the role of chemokines networks in the biology of breast cancer and metastasis to the bone. We also discuss the therapeutic opportunities and future prospects of targeting chemokine networks, in combination with other current standard therapies, for the treatment of bone-metastatic breast cancer.

Plasticity of patient-matched normal mammary epithelial cells is dependent on autologous adipose-derived stem cells

Due to the increasing clinical application of adipose-derived stem cells (ADSC), e.g. lipotransfer for breast reconstruction, this study aimed to gain novel insights regarding ADSC influence on breast tissue remodeling and determine patient-dependent factors affecting lipotransfer as well as begin to address its oncological risks. The ADSC secretome was analyzed from five normal breast reduction patients and contained elevated levels of growth factors, cytokines and proteins mediating invasion. ADSC/ADSC secretomes were tested for their influence on the function of primary mammary epithelial cells, and tumor epithelial cells using cell culture assays. ADSC/ADSC secretomes significantly stimulated proliferation, transmigration and 3D-invasion of primary normal and tumor epithelial cells. IL-6 significantly induced an EMT and invasion. The ADSC secretome significantly upregulated normal epithelial cell gene expression including MMPs and ECM receptors. Our study supports that ADSC and its secretome promote favorable conditions for normal breast tissue remodeling by changing the microenvironment. and may also be important regarding residual breast cancer cells following surgery.

Polymorphisms in the CCR5 promoter associated with cervical intraepithelial neoplasia in a Chinese Han population

Background

C-C chemokine receptor 5 (CCR5) has attracted wide concern for its critical role in the progression of human immunodeficiency virus type 1 (HIV-1) infection. Several studies have demonstrated that CCR5 affects the processes of tumor cell migration, invasion, and metastasis. The aim of this study was to illustrate the association between the polymorphisms of the CCR5 promoter and the development of cervical cancer.

Methods

336 women with cervical intraepithelial neoplasia (CIN), 488 women with cervical cancer (CC), and 682 healthy controls were recruited to detect polymorphisms in the CCR5 promoter using a sequencing method.

Results

Six loci with polymorphism were found in the CCR5 promoter; the frequencies of the minor alleles of rs1799987 was significantly higher in the CIN group than that in the control group (P = 0.007); and the genotypic frequencies of rs2734648, rs1799987, rs1799988 and rs1800023 were significantly different between the CIN group and the control group (P < 0.008). The inheritance model analysis showed that rs2734648, rs1799987, rs1799988 and rs1800023 significantly increased the susceptibility to CIN in a recessive genetic model (P < 0.008). The haplotype constructed by the major alleles of these 6 SNPs (rs2227010-rs1799987-rs1799988-rs2734648-rs1800023-rs1800024: A-G-A-C-A-T) was highly protective against CIN (OR = 0.731, 95%CI: 0.603–0.886, P = 5.68E-03). In addition, transcription prediction showed that mutation of these 6 SNPs might alternate the binding of particular transcription factors.

Conclusion

The CCR5 promoter polymorphisms were significantly associated with cervical intraepithelial neoplasia by altering the expression of CCR5 on the cell surface in a Chinese Han population.

The Role of Curcumin in Prevention and Management of Metastatic Disease

In the last two decades, targeted therapies have enhanced tumor patient care and treatment success, however, metastatic growth still cannot be stopped efficiently and, therefore, mortality rates remain high. Prevention strategies against formation of metastases are the most promising approach we have, however, due to lack of clinical validation studies, they have not yet entered routine clinical care. In order to smooth the way for efficient prevention, further preclinical and large clinical studies are required. In this context, the underlying molecular mechanisms and factors that lead to metastatic growth have to be explored, and potential preventive agents have to be tested. Thereby, special attention has to be paid to natural bioactive compounds which do not exert major adverse effects, like the plant-derived polyphenol Curcumin, which is known to be a powerful antitumor agent. So far, most of the preclinical studies with Curcumin have focused on its effect on inhibiting tumor cell proliferation and invasion, although, it is known that it also inhibits metastatic spread in vivo. This review discusses the preventive potential of this natural compound not only against tumor onset, but also against formation of metastases.

RANTES and IL-6 cooperate in inducing a more aggressive phenotype in breast cancer cells

Both the CC chemokine ligand 5 (CCL5/RANTES) and interleukin-6 (IL-6), released by mesenchymal stem cells (MSCs) as well as by neoplastic cells, promote breast cancer cell progression through autocrine and paracrine mechanisms. In order to assess the effects of the simultaneous overexpression of RANTES and IL-6 on the tumor cell phenotype, we overexpressed both proteins in MCF-7 and MDA-MB-231 human breast cancer cell lines. MCF-7 cells co-expressing RANTES and IL-6 had a greater ability to form colonies in soft agar, compared to cells overexpressing RANTES or IL-6. In addition, both MCF-7 and MDA-MB-231 clones co-expressing RANTES and IL-6 showed a significantly higher ability to migrate and to invade. The analysis of phosphorylated ERK1/2, AKT and STAT3 signal transduction proteins revealed that several signaling pathways are simultaneously activated in cells overexpressing both factors. Finally, the overexpression of RANTES and IL-6 in MCF-7 cells significantly increased the in vivo tumor growth. Collectively, our data suggest that the simultaneous expression of IL-6 and RANTES produces a more aggressive phenotype in breast cancer cells and provide evidence that IL-6 and RANTES might represent potential targets for novel therapeutic strategies aimed to block the tumor-stroma interaction.

Key roles of necroptotic factors in promoting tumor growth

Necroptotic factors are generally assumed to play a positive role in tumor therapy by eliminating damaged tumor cells. Here we show that, contrary to expectation, necroptotic factors RIPK1, RIPK3, and MLKL promote tumor growth. We demonstrate that genetic knockout of necroptotic genes RIPK1, RIPK3, or MLKL in cancer cells significantly attenuated their abilities to grow in an anchorage-independent manner. In addition, they exhibited significantly enhanced radiosensitivity. The knockout cells also showed greatly reduced ability to form tumors in mice. Moreover, necrosulfonamide (NSA), a previously identified chemical inhibitor of necroptosis, could significantly delay tumor growth in a xenograft model. Mechanistically, we show that necroptoic factors play a significant role in maintaining the activity of NF-κB. Finally, we found that high levels of phosphorylated MLKL in human esophageal and colon cancers are associated with poor overall survival. Taken together, we conclude that pro-necroptic factors such as RIPK1, RIPK3, and MLKL may play a role in supporting tumor growth, and MLKL may be a promising target for cancer treatment.

Clinical evaluation of macrophages in cancer: role in treatment, modulation and challenges

The focus of immunotherapeutics has been placed firmly on anti-tumour T cell responses. Significant progress has been made in the treatment of both local and systemic malignancies, but low response rates and rising toxicities are limiting this approach. Advancements in the understanding of tumour immunology are opening up a new range of therapeutic targets, including immunosuppressive factors in the tumour microenvironment. Macrophages are a heterogeneous group of cells that have roles in innate and adaptive immunity and tissue repair, but become co-opted by tumours to support tumour growth, survival, metastasis and immunosuppression. Macrophages also support tumour resistance to conventional therapy. In preclinical models, interference with macrophage migration, macrophage depletion and macrophage re-education have all been shown to reduce tumour growth and support anti-tumour immune responses. Here we discuss the role of macrophages in prognosis and sensitivity to therapy, while examining the significant progress which has been made in modulating the behaviour of these cells in cancer patients.

FXYD5 (dysadherin) may mediate metastatic progression through regulation of the β-Na+-K+-ATPase subunit in the 4T1 mouse breast cancer model

FXYD5 is a Na+-K+-ATPase regulator, expressed in a variety of normal epithelia. In parallel, it has been found to be associated with several types of cancer and effect lethal outcome by promoting metastasis. However, the molecular mechanism underlying FXYD5 mediated invasion has not yet been identified. In this study, using in vivo 4T1 murine breast cancer model, we found that FXYD5-specific shRNA significantly inhibited lung cancer metastasis, without having a substantial effect on primary tumor growth. Our study reveals that FXYD5 participates in multiple stages of metastatic development and exhibits more than one mode of E-cadherin regulation. We provide the first evidence that FXYD5-related morphological changes are mediated through its interaction with Na+-K+-ATPase. Experiments in cultured 4T1 cells have indicated that FXYD5 expression may downregulate the β1 isoform of the pump. This behavior could have implications on both transcellular interactions and intracellular events. Further studies suggest that differential localization of the adaptor protein Annexin A2 in FXYD5-expressing cells may correlate with matrix metalloproteinase 9 secretion and adhesion changes in 4T1 wild-type cells.

Extracellular Superoxide Dismutase Expression in Papillary Thyroid Cancer Mesenchymal Stem/Stromal Cells Modulates Cancer Cell Growth and Migration

Tumor stroma-secreted growth factors, cytokines, and reactive oxygen species (ROS) influence tumor development from early stages to the metastasis phase. Previous studies have demonstrated downregulation of ROS-producing extracellular superoxide dismutase (SOD3) in thyroid cancer cell lines although according to recent data, the expression of SOD3 at physiological levels stimulates normal and cancer cell proliferation. Therefore, to analyze the expression of SOD3 in tumor stroma, we characterized stromal cells from the thyroid. We report mutually exclusive desmoplasia and inflammation in papillary and follicular thyroid cancers and the presence of multipotent mesenchymal stem/stromal cells (MSCs) in non-carcinogenic thyroids and papillary thyroid cancer (PTC). The phenotypic and differentiation characteristics of Thyroid MSCs and PTC MSCs were comparable with bone marrow MSCs. A molecular level analysis showed increased FIBROBLAST ACTIVATING PROTEIN, COLLAGEN 1 TYPE A1, TENASCIN, and SOD3 expression in PTC MSCs compared to Thyroid MSCs, suggesting the presence of MSCs with a fibrotic fingerprint in papillary thyroid cancer tumors and the autocrine-paracrine conversion of SOD3 expression, which was enhanced by cancer cells. Stromal SOD3 had a stimulatory effect on cancer cell growth and an inhibitory effect on cancer cell migration, thus indicating that SOD3 might be a novel player in thyroid tumor stroma.

Potent Suppressive Effects of 1-Piperidinylimidazole Based Novel P2X7 Receptor Antagonists on Cancer Cell Migration and Invasion

The P2X7 receptor (P2X7R) has been reported as a key mediator in inflammatory processes and cancer invasion/metastasis. In this study, we report the discovery of novel P2X7R antagonists and their functional activities as potential antimetastatic agents. Modifications of the hydantoin core-skeleton and the side chain substituents of the P2X7R antagonist 7 were performed. The structure-activity relationships (SAR) and optimization demonstrated the importance of the sulfonyl group at the R1 position and the substituted position and overall size of R2 for P2X7R antagonism. The optimized novel analogues displayed potent P2X7 receptor antagonism (IC50 = 0.11-112 nM) along with significant suppressive effects on IL-1β release (IC50 = 0.32-210 nM). Moreover, representative antagonists (12g, 13k, and 17d) with imidazole and uracil core skeletons significantly inhibited the invasion of MDA-MB-231 triple negative breast cancer cells and cancer cell migration in a zebrafish xenograft model, suggesting the potential therapeutic application of these novel P2X7 antagonists to block metastatic cancer.

Integrated pharmacokinetic, pharmacodynamic and immunogenicity profiling of an anti-CCL21 monoclonal antibody in cynomolgus monkeys

QBP359 is an IgG1 human monoclonal antibody that binds with high affinity to human CCL21, a chemokine hypothesized to play a role in inflammatory disease conditions through activation of resident CCR7-expressing fibroblasts/myofibroblasts. The pharmacokinetics (PK) and pharmacodynamics (PD) of QBP359 in non-human primates were characterized through an integrated approach, combining PK, PD, immunogenicity, immunohistochemistry (IHC) and tissue profiling data from single- and multiple-dose experiments in cynomolgus monkeys. When compared with regular immunoglobulin typical kinetics, faster drug clearance was observed in serum following intravenous administration of 10 mg/kg and 50 mg/kg of QBP359. We have shown by means of PK/PD modeling that clearance of mAb-ligand complex is the most likely explanation for the rapid clearance of QBP359 in cynomolgus monkey. IHC and liquid chromatography mass spectrometry data suggested a high turnover and synthesis rate of CCL21 in tissues. Although lymphoid tissue was expected to accumulate drug due to the high levels of CCL21 present, bioavailability following subcutaneous administration in monkeys was 52%. In human disease states, where CCL21 expression is believed to be expressed at 10-fold higher concentrations compared with cynomolgus monkeys, the PK/PD model of QBP359 and its binding to CCL21 suggested that very large doses requiring frequent administration of mAb would be required to maintain suppression of CCL21 in the clinical setting. This highlights the difficulty in targeting soluble proteins with high synthesis rates.

Targeting the CCL2-CCR2 signaling axis in cancer metastasis

The CCL2-CCR2 signaling axis has generated increasing interest in recent years due to its association with the progression of cancer. Although first described as a chemotactic molecule with physiological roles in regulating inflammation, recent studies have revealed a pro-tumorigenic function for CCL2 in favoring cancer development and subsequent metastasis. CCL2 binds the cognate receptor CCR2, and together this signaling pair has been shown to have multiple pro-tumorigenic roles, from mediating tumor growth and angiogenesis to recruiting and usurping host stromal cells to support tumor progression. The importance of CCL2-CCR2 signaling has been further championed by the establishment of clinical trials targeting this signaling pair in solid and metastatic cancers. Here we review the roles of CCL2-CCR2 signaling in the development and progression of cancer metastasis. We further evaluate the outcome of several clinical trials targeting either CCL2 or CCR2, and discuss the prospects and challenges of manipulating CCL2-CCR2 interaction as a potential approach for combating metastatic disease.

Smac Mimetic-Induced Upregulation of CCL2/MCP-1 Triggers Migration and Invasion of Glioblastoma Cells and Influences the Tumor Microenvironment in a Paracrine Manner

Second mitochondria-derived activator of caspase (Smac) mimetics are considered as promising anticancer therapeutics that are currently under investigation in early clinical trials. They induce apoptosis by antagonizing inhibitor of apoptosis proteins, which are frequently overexpressed in cancer. We previously reported that Smac mimetics, such as BV6, additionally exert non-apoptotic functions in glioblastoma (GBM) cells by stimulating migration and invasion in a nuclear factor kappa B (NF-κB)-dependent manner. Because NF-κB target genes mediating these effects are largely unknown, we performed whole-genome expression analyses. Here, we identify chemokine (C-C motif) ligand 2 (CCL2) as the top-listed NF-κB-regulated gene being upregulated upon BV6 treatment in GBM cells. BV6-induced upregulation and secretion of CCL2 are required for migration and invasion of GBM cells because knockdown of CCL2 in GBM cells abolishes these effects. Co-culture experiments of GBM cells with non-malignant astroglial cells reveal that BV6-stimulated secretion of CCL2 by GBM cells into the supernatant triggers migration of astroglial cells toward GBM cells because CCL2 knockdown in BV6-treated GBM cells impedes BV6-stimulated migration of astroglial cells. In conclusion, we identify CCL2 as a BV6-induced NF-κB target gene that triggers migration and invasion of GBM cells and exerts paracrine effects on the GBM's microenvironment by stimulating migration of astroglial cells. These findings provide novel insights into the biological functions of Smac mimetics with important implications for the development of Smac mimetics as cancer therapeutics.

Trefoil Factor-3 (TFF3) Stimulates De Novo Angiogenesis in Mammary Carcinoma both Directly and Indirectly via IL-8/CXCR2

Mammary carcinoma cells produce pro-angiogenic factors to stimulate angiogenesis and tumor growth. Trefoil factor-3 (TFF3) is an oncogene secreted from mammary carcinoma cells and associated with poor prognosis. Herein, we demonstrate that TFF3 produced in mammary carcinoma cells functions as a promoter of tumor angiogenesis. Forced expression of TFF3 in mammary carcinoma cells promoted proliferation, survival, invasion and in vitro tubule formation of human umbilical vein endothelial cells (HUVEC). MCF7-TFF3 cells with forced expression of TFF3 generated tumors with enhanced microvessel density as compared to tumors formed by vector control cells. Depletion of TFF3 in mammary carcinoma cells by siRNA concordantly decreased the angiogenic behavior of HUVEC. Forced expression of TFF3 in mammary carcinoma cells stimulated IL-8 transcription and subsequently enhanced IL-8 expression in both mammary carcinoma cells and HUVEC. Depletion of IL-8 in mammary carcinoma cells with forced expression of TFF3, or antibody inhibition of IL-8, partially abrogated mammary carcinoma cell TFF3-stimulated HUVEC angiogenic behavior in vitro, as did inhibition of the IL-8 receptor, CXCR2. Depletion of STAT3 by siRNA in MCF-7 cells with forced expression of TFF3 partially diminished the angiogenic capability of TFF3 on stimulation of cellular processes of HUVEC. Exogenous recombinant hTFF3 also directly promoted the angiogenic behavior of HUVEC. Hence, TFF3 is a potent angiogenic factor and functions as a promoter of de novo angiogenesis in mammary carcinoma, which may co-coordinate with the growth promoting and metastatic actions of TFF3 in mammary carcinoma to enhance tumor progression.

CCL2-induced chemokine cascade promotes breast cancer metastasis by enhancing retention of metastasis-associated macrophages

Pulmonary metastasis of breast cancer cells is promoted by a distinct population of macrophages, metastasis-associated macrophages (MAMs), which originate from inflammatory monocytes (IMs) recruited by the CC-chemokine ligand 2 (CCL2). We demonstrate here that, through activation of the CCL2 receptor CCR2, the recruited MAMs secrete another chemokine ligand CCL3. Genetic deletion of CCL3 or its receptor CCR1 in macrophages reduces the number of lung metastasis foci, as well as the number of MAMs accumulated in tumor-challenged lung in mice. Adoptive transfer of WT IMs increases the reduced number of lung metastasis foci in Ccl3 deficient mice. Mechanistically, Ccr1 deficiency prevents MAM retention in the lung by reducing MAM-cancer cell interactions. These findings collectively indicate that the CCL2-triggered chemokine cascade in macrophages promotes metastatic seeding of breast cancer cells thereby amplifying the pathology already extant in the system. These data suggest that inhibition of CCR1, the distal part of this signaling relay, may have a therapeutic impact in metastatic disease with lower toxicity than blocking upstream targets.

Macrophage Inflammatory Protein-1 Alpha (MIP-1 alpha)/CCL3: As a Biomarker

Macrophage inflammatory protein-1 alpha (MIP-1α/CCL3) is a chemotactic chemokine secreted by macrophages. It performs various biological functions, such as recruiting inflammatory cells, wound healing, inhibition of stem cells, and maintaining effector immune response. It activates bone resorption cells and directly induces bone destruction. Cells that secrete MIP-1α/CCL3 are increased at sites of inflammation and bone resorption. MIP-1α/CCL3 plays an important role in the pathogenesis of various inflammatory diseases and conditions that exhibit bone resorption, such as periodontitis, multiple myeloma, Sjögren syndrome, and rheumatoid arthritis. Biological fluids from patients with these diseases exhibit elevated levels of MIP-1α/CCL3. This finding indicates that MIP-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \alpha $$\end{document}α/CCL3 protein may have diagnostic potential for the detection of several inflammatory diseases and conditions. This chapter discusses the biological functions of MIP-1α/CCL3; describes several diseases associated with MIP-1α/CCL3, particularly periodontitis; and delineates the potential application of MIP-1α/CCL3 as a biomarker.

Conditioning solid tumor microenvironment through inflammatory chemokines and S100 family proteins

Recently, there has been growing attention to the role of the tumor microenvironment (TME) in cancer growth, metastasis and emergence of chemotherapy resistance. Stromal and tumor cells make up the TME and interact with each other through a complex cross-talk manner. This interaction is facilitated by a variety of growth factors, cytokines, chemokines and S100 proteins. In this review, we focus on chemokines and their cognate receptors in regulating the tumorigenic process. Chemokines are cytokines that have chemotactic potential. Chemokine receptors are expressed on tumor cells and stromal cells. Chemokines and their cognate receptors modulate tumor growth and metastasis in a paracrine and autocrine manner. They play a major role in the modulation of stromal cell recruitment, angiogenic potential, cancer cell proliferation, survival, adhesion, invasion and metastasis to distant sites. In addition, a new class of calcium binding family S100 proteins has been getting attention as they play significant roles in tumor progression and metastasis by modulating TME. Here, we highlight recent developments regarding the inflammatory chemokine/S100 protein systems in the TME. We also focus on how chemokines/S100 proteins, through their role in the TME, modulate cancer cell ability to grow, proliferate, invade and metastasize to different organs. This review highlights the possibility of using the chemokine/chemokine receptor axis as a promising strategy in cancer therapy, the current difficulties in achieving this goal, and how it could be overcome for successful future therapeutic intervention.

CCR2-64I polymorphism is associated with Non-Small Cell Lung Cancer in Tunisian patients

Single nucleotide polymorphism (SNPs) in genes coding for chemokines may be associated with some cancer. The purpose of this study was to investigate the impact of CCR2-64I and CXCL12-3'A SNPs on the susceptibility and the clinicopathological characteristics of NSCLC (Non-Small Cell Lung Cancer) in the Tunisian population. 170 NSCLC patients and 225 healthy controls screened by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis were enrolled. A significant association for the homozygous genotype CCR2 64I/64I with lung cancer risk was observed (P=0.004). An increased significant frequency of the -64I allele (P=0.0006) was noted in the patient's group. Clinical analysis indicated a positive association of the -64I allele among squamous cell lung carcinoma patients (P=0.003). The CCR2 mRNA extracted from peripheral blood mononuclear cells (PBMC) was found highly expressed in NSCLC patients compared to controls. The same higher levels were found in patients carrying the CCR2 64I/64I genotype. No significant association was retrieved with CXCL12-3'A polymorphism. In conclusion, our results revealed that the subjects with -64I allele of CCR2-64I gene polymorphism, expressed a significantly higher risk for NSCLC risk without influence on its pathological progression.

Investigation of the roles of exosomes in colorectal cancer liver metastasis

The leading cause of death among cancer patients is tumor metastasis. Tumor-derived exosomes are emerging as mediators of metastasis. In the present study, we demonstrated that exosomes play a pivotal role in the metastatic progression of colorectal cancer. First, a nude mouse model of colorectal cancer liver metastasis was established and characterized. Then, we demonstrated that exosomes from a highly liver metastatic colorectal cancer cell line (HT-29) could significantly increase the metastatic tumor burden and distribution in the mouse liver of Caco-2 colorectal cancer cells, which ordinarily exhibit poor liver metastatic potential. We further investigated the mechanisms by which HT-29-derived-exosomes influence the liver metastasis of colorectal cancer and found that mice treated with HT-29-derived exosomes had a relatively higher level of CXCR4 in the metastatic microenvironment, indicating that exosomes may promote colorectal cancer metastasis by recruiting CXCR4-expressing stromal cells to develop a permissive metastatic microenvironment. Finally, the migration of Caco-2 cells was significantly increased following treatment with HT-29-derived exosomes in vitro, further supporting a role for exosomes in modulating colorectal tumor-derived liver metastasis. The data from the present study may facilitate further translational medicine research into the prevention and treatment of colorectal cancer liver metastasis.

A role for CCL2 in both tumor progression and immunosurveillance

The chemokine CCL2, which is best known for its chemotactic functions, is expressed not only by immune cells, but also by several types of malignant and stromal cells. CCL2 has been shown to exert both pro- and anti-tumor effects. However, recent results demonstrate a main role for CCL2 in tumor progression and metastasis, suggesting that this chemokine may constitute a therapeutic target for anticancer drugs. Mammary carcinoma models, including models of implantable, transgenic, and chemically-induced tumors, were employed in the setting of Ccl2 or Ccr2 knockout mice or CCL2 neutralization with a monoclonal antibody to further investigate the role of the CCL2/CCR2 signaling axis in tumor progression and metastatic spread. In our implantable tumor models, an anti-CCL2 monoclonal antibody inhibited the growth of primary malignant lesions in a biphasic manner and reduced the number of metastases. However, in Ccl2^-/- or Ccr2^-/- mice developing implanted or transgenic tumors, the number of pulmonary metastases was increased despite a reduction in the growth rate of primary neoplasms. Transgenic Mtag.Ccl2^-/- or Mtag.Ccr2^-/- mice also exhibited a significantly earlier of disease onset. In a chemical carcinogenesis model, anti-CCL2 monoclonal antibody inhibited the growth of established lesions but was ineffective in the tumor induction phase. In contrast to previous studies indicating a role for CCL2 in the establishment of metastases, we have demonstrated that the absence of CCL2/CCR2-signaling results in increased metastatic disease. Thus, the CCL2/CCR2 signaling axis appears to play a dual role in mediating early tumor immunosurveillance and sustaining the growth and progression of established neoplasms. Our findings support the use of anti-CCL2 therapies for the treatment of established breast carcinoma, although the complete abrogation of the CCL2 signaling cascade may also limit immunosurveillance and support metastatic spread.

Chemical targeting of GAPDH moonlighting function in cancer cells reveals its role in tubulin regulation

Glycolytic enzymes are attractive anticancer targets. They also carry out numerous, nonglycolytic "moonlighting" functions in cells. In this study, we investigated the anticancer activity of the triazine small molecule, GAPDS, that targets the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH). GAPDS showed greater toxicity against cancer cells compared to a known GAPDH enzyme inhibitor. GAPDS also selectively inhibited cell migration and invasion. Our analysis showed that GAPDS treatment reduced GAPDH levels in the cytoplasm, which would modulate the secondary, moonlighting functions of this enzyme. We then used GAPDS as a probe to demonstrate that a moonlighting function of GAPDH is tubulin regulation, which may explain its anti-invasive properties. We also observed that GAPDS has potent anticancer activity in vivo. Our study indicates that strategies to target the secondary functions of anticancer candidates may yield potent therapeutics and useful chemical probes.

BMP-2 promotes oral squamous carcinoma cell invasion by inducing CCL5 release

Bone morphogenetic protein-2 (BMP-2)-containing bone grafts are useful regenerative materials for oral and maxillofacial surgery; however, several in vitro and in vivo studies previously reported cancer progression-related adverse effects caused by BMP-2. In this study, by quantifying the rhBMP-2 content released from bone grafts, the rhBMP-2 concentration that did not show cytotoxicity in each cell line was determined and applied to the in vitro monoculture or coculture model in the invasion assay. Our results showed that 1 ng/ml rhBMP-2, while not affecting cancer cell viability, significantly increased the invasion ability of the cancer cells cocultured with fibroblasts. Cocultured medium with rhBMP-2 also contained increased levels of matrix metalloproteinases. rhBMP-2-treated cocultured fibroblasts did not show a prominent difference in mRNA expression profile. Some cytokines, however, were detected in the conditioned medium by a human cytokine antibody array. Among them, the cancer invasion-related factor CCL5 was quantified by ELISA. Interestingly, CCL5 neutralizing antibodies significantly reduced the invasion of oral cancer cells. In conclusion, our results suggest that 1 ng/ml rhBMP-2 may induce invasion of oral squamous cell carcinoma (OSCC) cells by CCL5 release in coculture models. Therefore, we propose that a careful clinical examination before the use of rhBMP-2-containing biomaterials is indispensable for using rhBMP-2 treatment to prevent cancer progression.

Interleukin-8 induces DNA synthesis, migration and down-regulation of cleaved caspase-3 in cultured human gingival epithelial cells

BACKGROUND AND OBJECTIVE

Migration of the junctional epithelium occurs in association with the formation of a periodontal pocket. Although the migration of junctional epithelium is known to be related to the proliferation and migration of gingival junctional epithelial cells, the mechanism has not been clarified. In patients with periodontitis, the levels of interleukin-8 (IL-8) in both gingival tissue and gingival crevicular fluid are dramatically increased. IL-8 has broad bioactive functions. In this study, we examined the role of IL-8 in DNA synthesis, migration and protection against apoptosis in cultured human gingival epithelial cells (HGEC).

MATERIAL AND METHODS

DNA synthesis was estimated by measuring the incorporation of bromodeoxyuridine. The migration of gingival epithelial cells was assessed in a wound-healing assay. The expression of integrin beta-1 was analyzed using immunofluorescence confocal microscopy and western blotting. Cleaved caspase-3 was detected using western blotting and a Caspase-Glo assay kit.

RESULTS

IL-8 increased the synthesis of DNA in HGEC, and the maximal effect was seen at 25 or 50 ng/mL of IL-8. In addition, 50 ng/mL of IL-8 induced cell migration, and a neutralizing antibody of integrin beta-1 inhibited the migration. IL-8 also activated expression of integrin beta-1. Furthermore, IL-8 reduced the Aggregatibacter actinomycetemcomitans-induced increase in caspase-3 expression in HGEC.

CONCLUSION

IL-8 may facilitate the migration of gingival junctional epithelium by enhancing DNA synthesis, migration and preventing apoptosis of gingival epithelial cells.

c-Jun N-Terminal Kinases Mediate a Wide Range of Targets in the Metastatic Cascade

Disseminated cancer cells rely on intricate interactions among diverse cell types in the tumor-associated stroma, vasculature, and immune system for survival and growth. Ubiquitous expression of c-Jun N-terminal kinase (jnk) genes in various cell types permits their control of metastasis. In early stages of metastasis, JNKs affect tumor-associated inflammation and angiogenesis as well as tumor cell migration and intravasation. Within the tumor stroma, JNKs are essential for the release of growth factors that promote epithelial-to-mesenchymal transition (EMT) in tumor cells. JNK3, the least ubiquitous isoform, facilitates angiogenesis by increasing endothelial cell migration. Importantly, JNK expression in tumor cells integrates stromal signals to promote tumor cell invasion. However, JNK isoforms differentially regulate migration toward the endothelial barrier. Once tumor cells enter the bloodstream, JNKs increase circulating tumor cell (CTC) survival and homing to tissues. By promoting fibrosis, JNKs improve CTC attachment to the endothelium. Once anchored, JNKs stimulate EMT to facilitate tumor cell extravasation and enhance the secretion of endothelial barrier disrupters. Tumor cells attract barrier-disrupting macrophages by JNK-dependent transcription of macrophage chemoattractant molecules. In the secondary tissue, JNKs are instrumental in the premetastatic niche and stimulate tumor cell proliferation. JNK expression in cancer cells stimulates tissue-remodeling macrophages to improve tumor colonization. However, in T-cells, JNKs alter cytokine production that increases tumor surveillance and inhibits the recruitment of tissue-remodeling macrophages. Therapeutically targeting JNKs for metastatic disease is attractive considering their promotion of metastasis; however, specific JNK tools are needed to determine their definitive actions within the context of the entire metastatic cascade.

Chlamydia trachomatis infection increases the expression of inflammatory tumorigenic cytokines and chemokines as well as components of the Toll-like receptor and NF-κB pathways in human prostate epithelial cells

Inflammation has been reported to play a major role in prostate carcinogenesis. Several bacterial infections can lead to prostate inflammation; however, until now, the precise molecular and cellular mechanisms linking inflammation to carcinogenesis have remained unclear. We therefore investigated the initiation of inflammation induced by Chlamydia trachomatis (C. trachomatis) infection in human prostate epithelial cells using an in vitro culture system in which human androgen-independent PC-3 prostate cancer epithelial cells were infected with C. trachomatis serovar L2. The expression levels of VEGF, ICAM-1, IL-6, IL-8, IL-1β, TNFα, CCL5, CCL2 and iNOS inflammation-related genes, as well as genes involved in the Toll-like receptor (TLR) pathway (TLR2, TLR4, CD14 and MyD88), were evaluated at the mRNA level in infected PC-3 cells 24 h after infection with C. trachomatis serovar L2. The expression levels of components of the NF-κB pathway (p65 and IκBα) were evaluated at the mRNA level in infected PC-3 cells at different time points (1, 6, 12 and 24 h) after infection. The expression levels of inflammation-related genes, components of the Toll-like receptor pathway and genes involved in NF-κB activation were analyzed in infected and uninfected cells using semi-quantitative RT-PCR. We detected a significant increase (p < 0.001) in inflammation-related cytokines in infected PC-3 cells. During infection, PC-3 cells elicited a proinflammatory response, as shown by NF-κB activation, TLR2 and TLR4 upregulation and the increased expression of inflammation-related genes. Furthermore, we observed significant upregulation of the adhesion molecules ICAM-1 and VEGF, which are two biomarkers correlated with tumor progression and immune system evasion. The present study suggests that human prostate cancer epithelial cells are susceptible to C. trachomatis infection and upregulate proinflammatory markers during infection.

Interleukin-32 increases human gastric cancer cell invasion associated with tumor progression and metastasis

PURPOSE

The proinflammatory cytokine interleukin-32 (IL-32) is a novel tumor marker highly expressed in various human carcinomas, including gastric cancer. However, its effects on prognosis of patients with gastric cancer and cancer metastasis are virtually unknown at present. The main aim of this study was to explore the clinical significance of IL-32 in gastric cancer and further elucidate the molecular mechanisms underlying IL-32-mediated migration and invasion.

EXPERIMENTAL DESIGN

Gastric cancer cells with ectopic expression or silencing of IL-32 were examined to identify downstream molecules and establish their effects on cell motility, invasion, and lung metastasis in vivo.

RESULTS

IL-32 was significantly upregulated in gastric cancer and positively correlated with aggressiveness of cancer and poor prognosis. Ectopic expression of IL-32 induced elongated morphology and increased cell migration and invasion via induction of IL-8, VEGF, matrix metalloproteinase 2 (MMP2), and MMP9 expression via phosphor-AKT/phospho-glycogen synthase kinase 3β/active β-catenin as well as hypoxia-inducible factor 1α (HIF-1α) signaling pathways. Conversely, depletion of IL-32 in gastric cancer cells reversed these effects and decreased lung colonization in vivo. Examination of gene expression datasets in oncomine and staining of gastric cancer specimens demonstrated the clinical significance of IL-32 and its downstream molecules by providing information on their coexpression patterns.

CONCLUSIONS

IL-32 contributes to gastric cancer progression by increasing the metastatic potential resulting from AKT, β-catenin, and HIF-1α activation. Our results clearly suggest that IL-32 is an important mediator for gastric cancer metastasis and independent prognostic predictor of gastric cancer.

Blockage of CXCR2 suppresses tumor growth of intrahepatic cholangiocellular carcinoma

BACKGROUND/AIMS

Complete operative resection is the only approach to cure for intrahepatic cholangiocellular carcinoma (ICC), but the disease's prognosis is notably poor. A novel therapeutic approach is urgently required. CXC chemokine receptor 2 (CXCR2) has been associated with tumorigenesis and metastasis in human cancers. In this study, we investigated the suppressive effect of ICC growth by blocking CXCR2.

MATERIAL AND METHODS

The role of CXCR2 was estimated using the human ICC cell lines, RBE and SSP25. CXCR2 small interfering RNA (siRNA) and an antagonist (SB225002) were used to block CXCR2. Proliferation assays, migration assays, and invasion assays were performed to confirm the suppressive effect of blocking CXCR2. Subcutaneous SSP25 tumors were established in athymic nude mice, and the mice were given SB225002. The expression of CXCR2 in ICC was determined by immunohistochemical staining of 34 ICC specimens. We investigated the relationship between CXCR2 expression and prognosis in ICC.

RESULTS

The prognosis of patients who had higher CXCR2 expression in ICC was significantly poor (P = .004). CXCR2 siRNA treatment significantly suppressed CXCR2 expression in both RBE and SSP25. Cell proliferation, migration, and invasion were significantly suppressed by both CXCR2 siRNA and SB225002 compared with the control group. SB225002 also suppressed the growth of transplanted subcutaneous tumors (P = .02) CONCLUSION: Our results demonstrated that blocking CXCR2 clearly suppressed the development of ICC. Blocking CXCR2 may be a promising therapeutic approach for ICC.

Constitutively active chemokine CXC receptors

Chemokines are low-molecular-weight, secreted proteins that act as leukocyte-specific chemoattractants. The chemokine family has more than 40 members. Based on the position of two conserved cysteines in the N-terminal domain, chemokines can be divided into the CXC, C, CC, and CX3C subfamilies. The interaction of chemokines with their receptors mediates signaling pathways that play critical roles in cell migration, differentiation, and proliferation. The receptors for chemokines are G protein-coupled receptors (GPCRs), and thus far, seven CXC receptors have been cloned and are designated CXCR1-7. Constitutively active GPCRs are present in several human immune-mediated diseases and in tumors, and they have provided valuable information in understanding the molecular mechanism of GPCR activation. Several constitutively active CXC chemokine receptors include the V6.40A and V6.40N mutants of CXCR1; the D3.49V variant of CXCR2; the N3.35A, N3.35S, and T2.56P mutants of CXCR3; the N3.35 mutation of CXCR4; and the naturally occurring KSHV-GPCR. Here, we review the regulation of CXC chemokine receptor signaling, with a particular focus on the constitutive activation of these receptors and the implications in physiological conditions and in pathogenesis. Understanding the mechanisms behind the constitutive activation of CXC chemokine receptors may aid in pharmaceutical design and the screening of inverse agonists and allosteric modulators for the treatment of autoimmune diseases and cancers.

Rac3 induces a molecular pathway triggering breast cancer cell aggressiveness: differences in MDA-MB-231 and MCF-7 breast cancer cell lines

Background

Rho GTPases are involved in cellular functions relevant to cancer. The roles of RhoA and Rac1 have already been established. However, the role of Rac3 in cancer aggressiveness is less well understood.

Methods

This work was conducted to analyze the implication of Rac3 in the aggressiveness of two breast cancer cell lines, MDA-MB-231 and MCF-7: both express Rac3, but MDA-MB-231 expresses more activated RhoA. The effect of Rac3 in cancer cells was also compared with its effect on the non-tumorigenic mammary epithelial cells MCF-10A. We analyzed the consequences of Rac3 depletion by anti-Rac3 siRNA.

Results

Firstly, we analyzed the effects of Rac3 depletion on the breast cancer cells’ aggressiveness. In the invasive MDA-MB-231 cells, Rac3 inhibition caused a marked reduction of both invasion (40%) and cell adhesion to collagen (84%), accompanied by an increase in TNF-induced apoptosis (72%). This indicates that Rac3 is involved in the cancer cells’ aggressiveness. Secondly, we investigated the effects of Rac3 inhibition on the expression and activation of related signaling molecules, including NF-κB and ERK. Cytokine secretion profiles were also analyzed. In the non-invasive MCF-7 line; Rac3 did not influence any of the parameters of aggressiveness.

Conclusions

This discrepancy between the effects of Rac3 knockdown in the two cell lines could be explained as follows: in the MDA-MB-231 line, the Rac3-dependent aggressiveness of the cancer cells is due to the Rac3/ERK-2/NF-κB signaling pathway, which is responsible for MMP-9, interleukin-6, -8 and GRO secretion, as well as the resistance to TNF-induced apoptosis, whereas in the MCF-7 line, this pathway is not functional because of the low expression of NF-κB subunits in these cells. Rac3 may be a potent target for inhibiting aggressive breast cancer.

Progesterone and calcitriol attenuate inflammatory cytokines CXCL1 and CXCL2 in ovarian and endometrial cancer cells

Cytokines/chemokines are key players in cancer-related inflammation. Increasing evidence suggests that chemokines produced by tumor cells are the mediators of metastasis. Thus, agents that can downregulate chemokines expression have potential against cancer metastasis. We have previously shown inhibition of ovarian and endometrial cancer cell growth with progesterone and calcitriol. In the present study, we evaluated the effect of these two agents on the expression of inflammatory genes. Using a RT-PCR array of inflammatory cytokines/chemokines and their receptors, we found a marked attenuation of CXCL1 and CXCL2 (GRO-α and -β) in cancer cells by both treatments. Knockdown of NFκB resulted in a reduced expression of CXCL1 and CXCL2 and the inhibitory effect of progesterone and calcitriol on the expression of chemokines was abrogated in NFκB-silenced cancer cells. Silencing of IκBα increased the expression of CXCL1 and CXCL2 in cancer cells, which can be attributed to the increased activation of NFκB-p65, caused by the lack of its inhibitor. Progesterone and calcitriol-induced inhibition was abolished in IκBα-knockdown cells. Our results demonstrate that suppression of IκBα phosphorylation by progesterone and calcitriol contributes to the reduced expression of CXCL1 and CXCL2. Downregulation of CXCL1 and CXCL2 was associated with a marked inhibition of metastasis-promoting genes. Overall, our results indicate that progesterone and calcitriol inhibit IκBα phosphorylation, NFκB activation, and the expression of NFκB regulated metastasis promoting genes. These results provide attractive data for the possible use of progesterone and calcitriol in the management of endometrial and ovarian tumors.

The fine balance of chemokines during disease: trafficking, inflammation, and homeostasis

The action of chemokines (or "chemotactic cytokines") is recognized as an integral part of inflammatory and regulatory processes. Leukocyte mobilization during physiological conditions, trafficking of various cell types during pathological conditions, cell activation, and angiogenesis are among the target functions exerted by chemokines upon signaling via their specific receptors. Current research is focused in analyzing changes in chemokine/chemokine receptor patterns during various diseases with the aim to modulate pathological trafficking of cells, or to attract particular cell types to specific tissues. This review focuses on defining the role(s) of certain chemokine ligands and receptors in inflammatory neurological conditions such as multiple sclerosis. In addition, the role(s) of chemokines in neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease is also described, as well as the contribution of chemokines to the pathogenesis of cancer, diabetes, and cardiovascular disease.

CCL2/CCR2 chemokine signaling coordinates survival and motility of breast cancer cells through Smad3 protein- and p42/44 mitogen-activated protein kinase (MAPK)-dependent mechanisms

Increased cell motility and survival are important hallmarks of metastatic tumor cells. However, the mechanisms that regulate the interplay between these cellular processes remain poorly understood. In these studies, we demonstrate that CCL2, a chemokine well known for regulating immune cell migration, plays an important role in signaling to breast cancer cells. We report that in a panel of mouse and human breast cancer cell lines CCL2 enhanced cell migration and survival associated with increased phosphorylation of Smad3 and p42/44MAPK proteins. The G protein-coupled receptor CCR2 was found to be elevated in breast cancers, correlating with CCL2 expression. RNA interference of CCR2 expression in breast cancer cells significantly inhibited CCL2-induced migration, survival, and phosphorylation of Smad3 and p42/44MAPK proteins. Disruption of Smad3 expression in mammary carcinoma cells blocked CCL2-induced cell survival and migration and partially reduced p42/44MAPK phosphorylation. Ablation of MAPK phosphorylation in Smad3-deficient cells with the MEK inhibitor U0126 further reduced cell survival but not migration. These data indicate that Smad3 signaling through MEK-p42/44MAPK regulates CCL2-induced cell motility and survival, whereas CCL2 induction of MEK-p42/44MAPK signaling independent of Smad3 functions as an alternative mechanism for cell survival. Furthermore, we show that CCL2-induced Smad3 signaling through MEK-p42/44MAPK regulates expression and activity of Rho GTPase to mediate CCL2-induced breast cancer cell motility and survival. With these studies, we characterize an important role for CCL2/CCR2 chemokine signaling in regulating the intrinsic relationships between breast cancer cell motility and survival with implications on the metastatic process.

Importance of chemokine (CC-motif) ligand 2 in breast cancer

Breast cancer is the leading cause of cancer-related death in women in the United States. Chemokine (CC-motif) ligand 2 (CCL2), an inflammatory cytokine and chemokine, is highly expressed within the tumor and stromal cell populations and has been associated with enhanced tumorigenesis. In breast cancer patients, CCL2 has been correlated with high tumor grade and has been shown to have significant prognostic value for relapse-free survival. CCL2 likely exerts its pro-tumorigenic effects through recruitment of tumor-associated macrophages (TAMs); TAMs promote a tumorigenic microenvironment through the induction of growth enhancers, angiogenic factors and inflammatory mediators. CCL2 may also stimulate angiogenesis independently of TAM recruitment as it is closely associated with several endothelial cell growth factors. Additionally, CCL2 has been implicated in several processes leading to metastatic establishment including the development of bone metastasis. It has also been reported to directly upregulate pro-tumorigenic inflammatory mediators, including regulated upon activation, normal T cell expressed and secreted (RANTES) and tumor necrosis factor-alpha (TNF-α). While there is emerging support for a tumor promoting role of CCL2 in breast cancer, additional research is required before CCL2 can be decisively established as a prognostic factor and/or treatment target in breast cancer.

Progression of cutaneous melanoma: implications for treatment

The survival rates of melanoma, like any type of cancer, become worse with advancing stage. Spectrum theory is most consistent with the progression of melanoma from the primary site to the in-transit locations, regional or sentinel lymph nodes and beyond to the distant sites. Therefore, early diagnosis and surgical treatment before its spread is the most effective treatment. Recently, new approaches have revolutionized the diagnosis and treatment of melanoma. Genomic profiling and sequencing will form the basis for molecular taxonomy for more accurate subgrouping of melanoma patients in the future. New insights of molecular mechanisms of metastasis are summarized in this review article. Sentinel lymph node biopsy has become a standard of care for staging primary melanoma without the need for a more morbid complete regional lymph node dissection. With recent developments in molecular biology and genomics, novel molecular targeted therapy is being developed through clinical trials.