CXCL12 and Vascular Endothelial Growth Factor Synergistically Induce Neoangiogenesis in Human Ovarian Cancers

A patent review of CXCR7 modulators (2019-present)

INTRODUCTION

Atypical chemokine receptor 3 (ACKR3) (formerly CXCR7) regulates various biological processes through its ligands and is closely associated with numerous diseases, including inflammation, cancer, cardiovascular diseases (CVDs), pain, and neurological disorders. Therefore, ACKR3 has emerged as a potential target for disease treatment.

AREAS COVERED

This review summarizes the ACKR3 modulators published in patents from 2019 to 2024 using data from Google Patents, the European Patent Office, and the World Intellectual Property Organization's online databases. This includes information on their chemical structures, syntheses, activities, and developmental stages.

EXPERT OPINION

ACKR3 agonists gained traction as a treatment for cardiovascular and pain conditions. WW-12, which was derived from the chemical modifications of conolidine, became a novel small-molecule pain modulator by activating ACKR3, which in turn boosted endogenous opioid peptides for the classical opioid receptors.ACKR3 antagonist ACT-1004-1239 from Idorsia Pharmaceuticals Ltd. has demonstrated the ability to treat cancer, acute lung injury/ARDS, and autoimmune diseases, including multiple sclerosis. The outcomes of these clinical trials will direct the development and indications of future ACKR3 modulators.

Crosstalk and communication of cancer-associated fibroblasts with natural killer and dendritic cells: New frontiers and unveiled opportunities for cancer immunotherapy

Natural killer (NK) cells and dendritic cells (DCs) are critical mediators of anti-cancer immune responses. In addition to their individual roles, NK cells and DCs are involved in intercellular crosstalk which is essential for the initiation and coordination of adaptive immunity against cancer. However, NK cell and DC activity is often compromised in the tumor microenvironment (TME). Recently, much attention has been paid to one of the major components of the TME, the cancer-associated fibroblasts (CAFs), which not only contribute to extracellular matrix (ECM) deposition and tumor progression but also suppress immune cell functions. It is now well established that CAFs support T cell exclusion from tumor nests and regulate their cytotoxic activity. In contrast, little is currently known about their interaction with NK cells, and DCs. In this review, we describe the interaction of CAFs with NK cells and DCs, by secreting and expressing various mediators in the TME of adult solid tumors. We also provide a detailed overview of ongoing clinical studies evaluating the targeting of stromal factors alone or in combination with immunotherapy based on immune checkpoint inhibitors. Finally, we discuss currently available strategies for the selective depletion of detrimental CAFs and for a better understanding of their interaction with NK cells and DCs.

Unraveling impact and potential mechanisms of baseline pain on efficacy of immunotherapy in lung cancer patients: a retrospective and bioinformatic analysis

Objective

Pain is a prevalent discomfort symptom associated with cancer, yet the correlations and potential mechanisms between pain and the efficacy of cancer immunotherapy remain uncertain.

Methods

Non-small cell lung cancer (NSCLC) patients who received immune checkpoint inhibitors (ICIs) in the inpatient department of Guangdong Provincial Hospital of Chinese Medicine from January 1, 2018, to December 31, 2021, were retrospectively enrolled. Through cox regression analysis, prognostic factors and independent prognostic factors affecting the efficacy of ICIs were identified, and a nomogram model was constructed. Hub cancer-related pain genes (CRPGs) were identified through bioinformatic analysis. Finally, the expression levels of hub CRPGs were detected using an enzyme-linked immunosorbent assay (ELISA).

Results

Before PSM, a total of 222 patients were enrolled in this study. Univariate and multivariate cox analysis indicated that bone metastasis and NRS scores were independent prognostic factors for the efficacy of ICIs. After PSM, a total of 94 people were enrolled in this study. Univariate cox analysis and multivariate cox analysis indicated that age, platelets, Dnlr, liver metastasis, bone metastasis, and NRS scores were independent prognostic factors for the efficacy of ICIs. A nomogram was constructed based on 6 independent prognostic factors with AUC values of 0.80 for 1-year, 0.73 for 2-year, and 0.80 for 3-year survival. ELISA assay results indicated that the level of CXCL12 significantly decreased compared to baseline after pain was relieved.

Conclusion

Baseline pain is an independent prognostic factor affecting the efficacy of ICIs in lung cancer, potentially through CXCL12-mediated inflammation promotion and immunosuppression.

Near-Infrared Stimuli-Responsive Hydrogel Promotes Cell Migration for Accelerated Diabetic Wound Healing

Diabetic wound healing including diabetic foot ulcers is a major clinical challenge, which could bring an increased level of mortality and morbidity. However, conventional wound dressings exhibit limited healing efficacy due to their lack of active modulation for the healing process. Here, a near-infrared (NIR) stimuli-responsive composite hydrogel dressing with the synergistic effect of both mechanical contraction and epithelial-mesenchymal transition (EMT) was developed to facilitate cell migration and vascularization for diabetic wound healing. In the methacrylated gelatin-based composite hydrogel, N-isopropylacrylamide and polydopamine nanoparticles were incorporated to endow the composite hydrogel with thermosensitive and photothermal properties. Linagliptin (LIN) was loaded into the composite hydrogel, and the drug release rate could be controlled by NIR laser irradiation. NIR-triggered on-demand active contraction of wound area and LIN release for biological stimulation were potentially realized in this responsive system due to the thermally induced sol-gel transition of the composite hydrogel. The release of loaded LIN could effectively promote cell migration by activating EMT and enhancing angiogenesis. In the full-thickness skin defect model, the LIN-loaded composite hydrogel with NIR laser irradiation had the highest wound closure rate as compared with the pure hydrogel and LIN-loaded hydrogel groups. Therefore, this composite hydrogel can serve as an excellent platform for promoting wound healing and will find more practical value in clinical treatment.

Proteomic insights into breast cancer response to brain cell-secreted factors

The most devastating feature of cancer cells is their ability to metastasize to distant sites in the body. HER2 + and TN breast cancers frequently metastasize to the brain and stay potentially dormant for years until favorable conditions support their proliferation. The sheltered and delicate nature of the brain prevents, however, early disease detection and effective delivery of therapeutic drugs. Moreover, the challenges associated with the acquisition of brain biopsies add compounding difficulties to exploring the mechanistic aspects of tumor development. To provide insights into the determinants of cancer cell behavior at the brain metastatic site, this study was aimed at exploring the early response of HER2 + breast cancer cells (SKBR3) to factors present in the brain perivascular niche. The neural microenvironment was simulated by using the secretome of a set of brain cells that come first in contact with the cancer cells upon crossing the blood brain barrier, i.e., endothelial cells, astrocytes, and microglia. Cytokine microarrays were used to investigate the secretome mediators of intercellular communication, and proteomic technologies for assessing the changes in the behavior of cancer cells upon exposure to the brain cell-secreted factors. The cytokines detected in the brain secretomes were supportive of inflammatory conditions, while the SKBR3 cells secreted numerous cancer-promoting growth factors that were either absent or present in lower abundance in the brain cell cultures, indicating that upon exposure the SKBR3 cells may have been deprived of favorable conditions for optimal growth. Altogether, the results suggest that the exposure of SKBR3 cells to the brain cell-secreted factors altered their growth potential and drove them toward a state of quiescence, with broader overall outcomes that affected cellular metabolism, adhesion and immune response processes. The findings of this study underscore the key role played by the neural niche in shaping the behavior of metastasized cancer cells, provide insights into the cellular cross-talk that may lead cancer cells into dormancy, and highlight novel opportunities for the development of metastatic breast cancer therapeutic strategies.

Chemokine receptors and their ligands in breast cancer: The key roles in progression and metastasis

Chemokines and their receptors are a family of chemotactic cytokines with important functions in the immune response in both health and disease. Their known physiological roles such as the regulation of leukocyte trafficking and the development of immune organs generated great interest when it was found that they were also related to the control of early and late inflammatory stages in the tumor microenvironment. In fact, in breast cancer, an imbalance in the synthesis of chemokines and/or in the expression of their receptors was attributed to be involved in the regulation of disease progression, including invasion and metastasis. Research in this area is progressing rapidly and the development of new agents based on chemokine and chemokine receptor antagonists are emerging as attractive alternative strategies. This chapter provides a snapshot of the different functions reported for chemokines and their receptors with respect to the potential to regulate breast cancer progression.

PAD4 controls tumor immunity via restraining the MHC class II machinery in macrophages

Tumor-associated macrophages (TAMs) shape tumor immunity and therapeutic efficacy. However, it is poorly understood whether and how post-translational modifications (PTMs) intrinsically affect the phenotype and function of TAMs. Here, we reveal that peptidylarginine deiminase 4 (PAD4) exhibits the highest expression among common PTM enzymes in TAMs and negatively correlates with the clinical response to immune checkpoint blockade. Genetic and pharmacological inhibition of PAD4 in macrophages prevents tumor progression in tumor-bearing mouse models, accompanied by an increase in macrophage major histocompatibility complex (MHC) class II expression and T cell effector function. Mechanistically, PAD4 citrullinates STAT1 at arginine 121, thereby promoting the interaction between STAT1 and protein inhibitor of activated STAT1 (PIAS1), and the loss of PAD4 abolishes this interaction, ablating the inhibitory role of PIAS1 in the expression of MHC class II machinery in macrophages and enhancing T cell activation. Thus, the PAD4-STAT1-PIAS1 axis is an immune restriction mechanism in macrophages and may serve as a cancer immunotherapy target.

High density of CXCL12-positive immune cell infiltration predicts chemosensitivity and recurrence-free survival in ovarian carcinoma

BACKGROUND

Ovarian carcinoma is the most lethal gynecologic malignancy because of its late diagnosis, extremely high recurrence rate, and limited curative treatment options. In clinical practice, high-grade serous carcinoma (HGSC) predominates due to its frequency, high aggressiveness, and rapid development of drug resistance. Recent evidence suggests that CXCL12 is an important immunological factor in ovarian cancer progression. Therefore, we investigated the predictive and prognostic significance of the expression of this chemokine in tumor and immune cells in patients with HGSC.

METHODS

We studied a cohort of 47 primary high-grade serous ovarian carcinomas and their associated recurrences. A tissue microarray was constructed to evaluate the CXCL12 immunostained tumor tissue. CXCL12 expression was evaluated and statistically analyzed to correlate clinicopathologic data, overall survival, and recurrence-free survival.

RESULTS

A high proportion of CXCL12 + positive immune cells in primary ovarian serous carcinoma correlated significantly with chemosensitivity (p = 0.005), overall survival (p = 0.021), and longer recurrence-free survival (p = 0.038). In recurrent disease, high expression of CXCL12 was also correlated with better overall survival (p = 0.040). Univariate and multivariate analysis revealed that high CXCL12 + tumor-infiltrating immune cells (TICs) (HR 0.99, p = 0.042, HR 0.99, p = 0.023, respectively) and combined CXCL12 + /CD66b + infiltration (HR 0.15, p = 0.001, HR 0.13, p = 0.001, respectively) are independent favorable predictive markers for recurrence-free survival.

CONCLUSION

A high density of CXCL12 + TICs predicts a good response to chemotherapy, leading to a better overall survival and a longer recurrence-free interval. Moreover, with concomitant high CXCL12/CD66b TIC density, it is an independent favorable predictor of recurrence-free survival in patients with ovarian carcinoma.

Charting a killer course to the solid tumor: strategies to recruit and activate NK cells in the tumor microenvironment

The ability to expand and activate natural Killer (NK) cells ex vivo has dramatically changed the landscape in the development of novel adoptive cell therapies for treating cancer over the last decade. NK cells have become a key player for cancer immunotherapy due to their innate ability to kill malignant cells while not harming healthy cells, allowing their potential use as an "off-the-shelf" product. Furthermore, recent advancements in NK cell genetic engineering methods have enabled the efficient generation of chimeric antigen receptor (CAR)-expressing NK cells that can exert both CAR-dependent and antigen-independent killing. Clinically, CAR-NK cells have shown promising efficacy and safety for treating CD19-expressing hematologic malignancies. While the number of pre-clinical studies using CAR-NK cells continues to expand, it is evident that solid tumors pose a unique challenge to NK cell-based adoptive cell therapies. Major barriers for efficacy include low NK cell trafficking and infiltration into solid tumor sites, low persistence, and immunosuppression by the harsh solid tumor microenvironment (TME). In this review we discuss the barriers posed by the solid tumor that prevent immune cell trafficking and NK cell effector functions. We then discuss promising strategies to enhance NK cell infiltration into solid tumor sites and activation within the TME. This includes NK cell-intrinsic and -extrinsic mechanisms such as NK cell engineering to resist TME-mediated inhibition and use of tumor-targeted agents such as oncolytic viruses expressing chemoattracting and activating payloads. We then discuss opportunities and challenges for using combination therapies to extend NK cell therapies for the treatment of solid tumors.

Proteomic Insights into Metastatic Breast Cancer Response to Brain Cell-Secreted Factors

The most devastating feature of cancer cells is their ability to metastasize to distant sites in the body. HER2+ and triple negative breast cancers frequently metastasize to the brain and stay potentially dormant for years, clinging to the microvasculature, until favorable environmental conditions support their proliferation. The sheltered and delicate nature of the brain prevents, however, early disease detection, diagnosis, and effective delivery of therapeutic drugs. Moreover, the challenges associated with the acquisition of brain tissues and biopsies add compounding difficulties to exploring the mechanistic aspects of tumor development, leading to slow progress in understanding the drivers of disease progression and response to therapy. To provide insights into the determinants of cancer cell behavior at the brain metastatic site, this study was aimed at exploring the growth and initial response of HER2+ breast cancer cells (SKBR3) to factors present in the brain perivascular niche. The neural microenvironment conditions were simulated by using the secretome of a set of brain cells that come first in contact with the cancer cells upon crossing the blood brain barrier, i.e., human endothelial cells (HBEC5i), human astrocytes (NHA) and human microglia (HMC3) cells. Cytokine microarrays were used to investigate the cell secretomes and explore the mediators responsible for cell-cell communication, and proteomic technologies for assessing the changes in the behavior of cancer cells upon exposure to the brain cell-secreted factors. The results of the study suggest that the exposure of SKBR3 cells to the brain secretomes altered their growth potential and drove them towards a state of quiescence. The cytokines, growth factors and enzymes detected in the brain cell-conditioned medium were supportive of mostly inflammatory conditions, indicating a collective functional contribution to cell activation, defense, inflammatory responses, chemotaxis, adhesion, angiogenesis, and ECM organization. The SKBR3 cells, on the other hand, secreted numerous cancer-promoting growth factors that were either absent or present in lower abundance in the brain cell culture media, suggesting that upon exposure the SKBR3 cells were deprived of favorable environmental conditions required for optimal growth. The findings of this study underscore the key role played by the neural niche in shaping the behavior of metastasized cancer cells, providing insights into the cancer-host cell cross-talk that contributes to driving metastasized cancer cells into dormancy and into the opportunities that exist for developing novel therapeutic strategies that target the brain metastases of breast cancer.

Lipid-based nanoparticles for cancer immunotherapy

As the fourth most important cancer management strategy except surgery, chemotherapy and radiotherapy, cancer immunotherapy has been confirmed to elicit durable antitumor effects in the clinic by leveraging the patient's own immune system to eradicate the cancer cells. However, the limited population of patients who benefit from the current immunotherapies and the immune related adverse events hinder its development. The immunosuppressive microenvironment is the main cause of the failure, which leads to cancer immune evasion and immunity cycle blockade. Encouragingly, nanotechnology has been engineered to enhance the efficacy and reduce off-target toxicity of their therapeutic cargos by spatiotemporally controlling the biodistribution and release kinetics. Among them, lipid-based nanoparticles are the first nanomedicines to make clinical translation, which are now established platforms for diverse areas. In this perspective, we discuss the available lipid-based nanoparticles in research and market here, then describe their application in cancer immunotherapy, with special emphasis on the T cells-activated and macrophages-targeted delivery system. Through perpetuating each step of cancer immunity cycle, lipid-based nanoparticles can reduce immunosuppression and promote drug delivery to trigger robust antitumor response.

Neo-vascularization-based therapeutic perspectives in advanced ovarian cancer

The process of angiogenesis is well described for its potential role in the development of normal ovaries, and physiological functions as well as in the initiation, progression, and metastasis of ovarian cancer (OC). In advanced stages of OC, cancer cells spread outside the ovary to the pelvic, abdomen, lung, or multiple secondary sites. This seriously limits the efficacy of therapeutic options contributing to fatal clinical outcomes. Notably, a variety of angiogenic effectors are produced by the tumor cells to initiate angiogenic processes leading to the development of new blood vessels, which provide essential resources for tumor survival, dissemination, and dormant micro-metastasis of tumor cells. Multiple proangiogenic effectors and their signaling axis have been discovered and functionally characterized for potential clinical utility in OC. In this review, we have provided the current updates on classical and emerging proangiogenic effectors, their signaling axis, and the immune microenvironment contributing to the pathogenesis of OC. Moreover, we have comprehensively reviewed and discussed the significance of the preclinical strategies, drug repurposing, and clinical trials targeting the angiogenic processes that hold promising perspectives for the better management of patients with OC.

HDAC inhibitor HPTA initiates anti-tumor response by CXCL9/10-recruited CXCR3+CD4+T cells against PAHs carcinogenicity

Polycyclic aromatic hydrocarbons (PAHs) exposure in food is closely associated with the occurrence and development of breast cancer, which may attribute to altered immunotoxicity and immune regulation. Currently, cancer immunotherapy aims to promote tumor-specific T cell responses, especially CD4⁺T helper cells (Th) for anti-tumor immunity. The histone deacetylase inhibitors (HDACis) are found to exert an anti-tumor effect by reshaping the tumor immune microenvironment, but the immune regulatory mechanism of HDACis in PAHs-induced breast tumor remains elusive. Here, using established breast cancer models induced by 7,12-dimethylbenz[a]anthracene (DMBA), a potent carcinogenic agent of PAH, the novel HDACi, 2-hexyl-4-pentylene acid (HPTA) exhibited anti-tumor effect by activating T lymphocytes immune function. HPTA recruited CXCR3⁺CD4⁺T cells into chemokines CXCL9/10-enriched tumor sites, the increased secretion of CXCL9/10 was regulated by the NF-κB-mediated pathway. Furthermore, HPTA promoted Th1 differentiation and assisted cytotoxic CD8⁺T cells in the elimination of breast cancer cells. These findings support the proposition of HPTA as a potential therapeutic in the treatment of PAHs-induced carcinogenicity.

Flavokawain A suppresses the vasculogenic mimicry of HCC by inhibiting CXCL12 mediated EMT

BACKGROUND

Hepatocellular carcinoma has high ability of vascular invasion and metastasis. Vasculogenic mimicry (VM) is closely related to the metastasis and recurrence of hepatocellular carcinoma (HCC). According to previous research, Chloranthus henryi has anti-tumor effect, but its molecular mechanism in the treatment of HCC has not yet been stated.

PURPOSE

In our study, we aimed to investigate the effect of the extract of Chloranthus henryi in HCC and its target and molecular mechanism. We hoped to explore potential drugs for HCC treatment.

STUDY DESIGN/METHODS

In this study, we isolated a chalcone compound from Chloranthus henryi, compound 4, identified as flavokawain A (FKA). We determined the anti-HCC effect of FKA by MTT and identified the target of FKA by molecular docking and CETSA. Hepatoma cells proliferation, migration, invasion, and VM formation were examined using EDU, wound healing, transwell, vasculogenic mimicry, and IF. WB, RT-PCR, and cell transfection were used to explore the mechanism of FKA on hepatoma cells. Tissue section staining is mainly used to demonstrate the effect of FKA on HCC in vivo.

RESULTS

We confirmed that FKA can directly interact with CXCL12 and HCC proliferation, migration, invasion, and VM formation were all inhibited through reversing the EMT progress in vitro and in vivo through the PI3K/Akt/NF-κB signaling pathway. Additionally, by overexpressing and knocking down CXCL12, we got the same results.

CONCLUSION

FKA attenuated proliferation, invasion and metastatic and reversed EMT in HCC via PI3K/Akt/HIF-1α/NF-κB/Twist1 pathway by targeting CXCL12. This study proposed that FKA may be a candidate drug and prospective strategy for HCC therapy.

Lysophosphatidylinositol Promotes Chemotaxis and Cytokine Synthesis in Mast Cells with Differential Participation of GPR55 and CB2 Receptors

Mast cells (MCs) are the main participants in the control of immune reactions associated with inflammation, allergies, defense against pathogens, and tumor growth. Bioactive lipids are lipophilic compounds able to modulate MC activation. Here, we explored some of the effects of the bioactive lipid lysophosphatidylinositol (LPI) on MCs. Utilizing murine bone marrow-derived mast cells (BMMCs), we found that LPI did not cause degranulation, but slightly increased FcεRI-dependent β-hexosaminidase release. However, LPI induced strong chemotaxis together with changes in LIM kinase (LIMK) and cofilin phosphorylation. LPI also promoted modifications to actin cytoskeleton dynamics that were detected by an increase in cell size and interruptions in the continuity of the cortical actin ring. The chemotaxis and cortical actin ring changes were dependent on GPR55 receptor activation, since the specific agonist O1602 mimicked the effects of LPI and the selective antagonist ML193 prevented them. The LPI and O1602-dependent stimulation of BMMC also led to VEGF, TNF, IL-1α, and IL-1β mRNA accumulation, but, in contrast with chemotaxis-related processes, the effects on cytokine transcription were dependent on GPR55 and cannabinoid (CB) 2 receptors, since they were sensitive to ML193 and to the specific CB2 receptor antagonist AM630. Remarkably, GPR55-dependent BMMC chemotaxis was observed towards conditioned media from distinct mouse and human cancer cells. Our data suggest that LPI induces the chemotaxis of MCs and leads to cytokine production in MC in vitro with the differential participation of GPR55 and CB2 receptors. These effects could play a significant role in the recruitment of MCs to tumors and the production of MC-derived pro-angiogenic factors in the tumor microenvironment.

Reprogramming the tumor microenvironment leverages CD8+ T cell responses to a shared tumor/self antigen in ovarian cancer

Tumor antigen-driven responses to weakly immunogenic self-antigens and neoantigens directly affect treatment efficacy following immunotherapy. Using orthotopically grown SV40 T antigen+ ovarian carcinoma in antigen-naive wild-type or TgMISIIR-TAg-Low transgenic mice expressing SV40 T antigen as a self-antigen, we investigated the impact of CXCR4-antagonist-armed oncolytic virotherapy on tumor progression and antitumor immunity. Immunostaining and single-cell RNA sequencing analyses of the peritoneal tumor microenvironment of untreated tumors in syngeneic wild-type mice revealed the presence of SV40 T antigen-specific CD8+ T cells, a balanced M1/M2 transcriptomic signature of tumor-associated macrophages, and immunostimulatory cancer-associated fibroblasts. This contrasted with polarized M2 tumor-associated macrophages, immunosuppressive cancer-associated fibroblasts, and poor immune activation in TgMISIIR-TAg-Low mice. Intraperitoneal delivery of CXCR4-antagonist-armed oncolytic vaccinia virus led to nearly complete depletion of cancer-associated fibroblasts, M1 polarization of macrophages, and generation of SV40 T antigen-specific CD8+ T cells in transgenic mice. Cell depletion studies revealed that the therapeutic effect of armed oncolytic virotherapy was dependent primarily on CD8+ cells. These results demonstrate that targeting the interaction between immunosuppressive cancer-associated fibroblasts and macrophages in the tolerogenic tumor microenvironment by CXCR4-A-armed oncolytic virotherapy induces tumor/self-specific CD8+ T cell responses and consequently increases therapeutic efficacy in an immunocompetent ovarian cancer model.

Strategy and application of manipulating DCs chemotaxis in disease treatment and vaccine design

As the most versatile antigen-presenting cells (APCs), dendritic cells (DCs) function as the cardinal commanders in orchestrating innate and adaptive immunity for either eliciting protective immune responses against canceration and microbial invasion or maintaining immune homeostasis/tolerance. In fact, in physiological or pathological conditions, the diversified migratory patterns and exquisite chemotaxis of DCs, prominently manipulate their biological activities in both secondary lymphoid organs (SLOs) as well as homeostatic/inflammatory peripheral tissues in vivo. Thus, the inherent mechanisms or regulation strategies to modulate the directional migration of DCs even could be regarded as the crucial cartographers of the immune system. Herein, we systemically reviewed the existing mechanistic understandings and regulation measures of trafficking both endogenous DC subtypes and reinfused DCs vaccines towards either SLOs or inflammatory foci (including neoplastic lesions, infections, acute/chronic tissue inflammations, autoimmune diseases and graft sites). Furthermore, we briefly introduced the DCs-participated prophylactic and therapeutic clinical application against disparate diseases, and also provided insights into the future clinical immunotherapies development as well as the vaccines design associated with modulating DCs mobilization modes.

On-Chip Organoid Formation to Study CXCR4/CXCL-12 Chemokine Microenvironment Responses for Renal Cancer Drug Testing

Organoid models have gained importance in recent years in determining the toxic effects of drugs in cancer studies. Organoid designs with the same standardized size and cellular structures are desired for drug tests. The field of microfluidics offers numerous advantages to enable well-controlled and contamination-free biomedical research. In this study, simple and low-cost microfluidic devices were designed and fabricated to develop an organoid model for drug testing for renal cancers. Caki human renal cancer cells and mesenchymal stem cells isolated from human umbilical cord were placed into alginate hydrogels. The microfluidic system was implemented to form size-controllable organoids within alginate hydrogels. Alginate capsules of uniform sizes formed in the microfluidic system were kept in cell culture for 21 days, and their organoid development was studied with calcein staining. Cisplatin was used as a standard chemotherapeutic, and organoid sphere structures were examined as a function of time with an MTT assay. HIF-1α, CXCR4 and CXCL-12 chemokine protein, and CXCR4 and CXCL-12 gene levels were tested in organoids and cisplatin responses. In conclusion, it was found that the standard renal cancer organoids made on a lab-on-a-chip system can be used to measure drug effects and tumor microenvironment responses.

Increasing oxygen tension in tumor tissue using ultrasound sensitive O2 microbubbles

Low tissue oxygenation significantly impairs the effectiveness of cancer therapy and promotes a more aggressive phenotype. Many strategies to improve tissue oxygenation have been proposed throughout the years, but only a few showed significant effects in clinical settings. We investigated stability and ultrasound pulse (UP) triggered oxygen release from phospholipid coated oxygen microbubbles (OMB) in vitro and in murine tumors in vivo using EPR oximetry. In solution, the investigated microbubbles are stable and responsive to ultrasound pulse. The addition of the OMB solution alone resulted in an increase in pO₂ of approximately 70 mmHg which was further increased for an additional 80 mmHg after the application of UP. The in vivo kinetic study revealed a substantial, up to 120 mmHg, increase in tumor pO₂ after UP application and then pO₂ was decreasing for 20 min for intravenous injection and 15 min for intratumoral injection. A significant increase was also observed in groups that received microbubbles filled with nitrogen and ultrasound pulse and OMB without UP, but the effect was much lower. Oxygen microbubbles lead to a decrease in HIF-1a and VEGF-A both at the level of mRNA and protein. Toxicity analysis showed that intravenous injection of OMB does not cause oxidative damage to the heart, liver, or kidneys. However, elevated levels of oxidative damage to lipids and proteins were observed short-term in tumor tissue. In conclusion, we have demonstrated the feasibility of oxygen microbubbles in delivering oxygen effectively and safely to the tumor in living animals. Such treatment might enhance the effectiveness of other anticancer therapies.

Sulfamethoxazole induces brain capillaries toxicity in zebrafish by up-regulation of VEGF and chemokine signalling

Sulfamethoxazole (SMX) is a widespread broad-spectrum bacteriostatic antibiotic. Its residual is frequently detected in the water and may therefore bioaccumulate in the brain of aquatic organisms via blood circulation. Brain capillaries toxicity is very important for brain development. However, little information is available in the literature to show the toxicity of SMX to brain development. To study the SMX's brain toxic effects and the related mechanisms, we exposed zebrafish embryos to SMX at different concentrations (0 ppm, 1 ppm, 25 ppm, 100 ppm and 250 ppm) and found that high concentration (250 ppm) of SMX would not only caused an abnormal in malformation rate, hatching rate, body length and survival rate of zebrafish embryos, but also lead to brain oedema. In addition, SMX also induced cerebral ischaemia, aggravates oxidative stress, and changes genes related to oxidative stress (sod1, cat, gpx4, and nrf2). Furthermore, ischaemia caused by SMX could promote ectopic angiogenesis in brain via activating the angiogenesis-related genes (vegfab, cxcr4a, cxcl12b) from 24 h to 53 h. Inhibition of VEGF signalling by SU5416, or inhibition of chemokine downstream PI3K signalling by LY294002, could rescue the brain capillaries toxicity and brain oedema induced by SMX. Our results provide new evidence for the brain toxicity of SMX and its residual danger in the environment and aquatic organisms.

Basic fibroblast growth factor uniquely stimulates quiescent vascular smooth muscle cells and induces proliferation and dedifferentiation

Blood vessels normally remain stable over the long-term. However, in atherosclerosis, vascular cells leave the quiescent state and enter an activated state. Here, we investigated the factors that trigger breakage of the quiescent state by screening growth factors and cytokines using a vascular smooth muscle cell (SMC) line and an endothelial cell (EC) line. Despite known functions of the tested factors, only basic fibroblast growth factor (bFGF) was identified as a potent trigger of quiescence breakage in SMCs, but not ECs. bFGF disrupted tight SMC-monolayers, and caused morphological changes, proliferation and dedifferentiation. Human primary SMCs, but not ECs, also showed similar results. Aberrant SMC-proliferation is a critical histological event in atherosclerosis. We thus provide further insights into the role of bFGF in vascular pathobiology.

Enhancing tumor T cell infiltration to enable cancer immunotherapy

Cancer immunotherapy has changed the treatment landscape for cancer patients, especially for those with metastatic spread. While the immunotherapeutic armamentarium is constantly growing, as exemplified by approved compounds, clinical outcome remains variable both within and across entities. A sufficient infiltration into the tumor microenvironment and successful activation of effector T lymphocytes against tumor cells have been identified as predictors for responses to T cell-based immunotherapies. However, tumor cells have developed a variety of mechanisms to reduce T cell homing and access to the tumor tissue to prevent activity of anticancer immunity. As a consequence, investigations have interrogated strategies to improve the efficacy of cancer immunotherapies by enhancing T cell infiltration into tumor tissues. In this review, we summarize mechanisms of how tumor tissue shapes immune suppressive microenvironment to prevent T cell access to the tumor site. We focus on current strategies to improve cancer immunotherapies through enhancing T cell infiltration.

miRNA expression changes during the course of neoadjuvant bevacizumab and chemotherapy treatment in breast cancer

One of the hallmarks of cancer is sustained angiogenesis. Favorable results have been reported in some breast cancer (BC) patients receiving antiangiogenic therapy with bevacizumab (Bev) in combination with chemotherapy, and further knowledge on how Bev can be optimally combined with conventional treatment to increase efficacy is strongly needed. In this randomized, neoadjuvant phase II clinical trial, 132 patients with HER2-negative, nonmetastatic BC were treated with Bev in combination with sequential chemotherapy. Biopsies were sampled before treatment, after 12 weeks with anthracycline and after taxane therapy at week 25. MicroRNA (miRNA) expression profiling was performed on biopsies from each time point. Altogether, 241 biopsies were analyzed with the aim of identifying miRNA-based biomarkers of response to therapy. Results from the miRNA analyses were reported for the ER-positive cohort, which were previously demonstrated to benefit from antiangiogenic therapy in this study. For both treatment arms of this cohort, significantly different expression was observed for 217 miRNAs between objective responding and nonresponding patients before treatment initiation. These miRNAs have been linked to regulation of epithelial-mesenchymal transition, metastasis, and tumor growth, among other processes. Bev in combination with chemotherapy resulted in similar miRNA changes to chemotherapy alone. However, the deregulation of miRNA expression occurred earlier in the Bev arm. In both arms, tumor suppressor miRNAs were found upregulated after treatment, while oncogenic miRNAs were downregulated in the Bev arm. Patients responding to Bev showed a strong correlation between deregulated miRNAs and decreased proliferation score during the course of treatment, with downregulation of miR-4465 as the strongest indicator of reduced proliferation. Integrative analyses at miRNA-, gene-, and protein expression further indicated a longitudinal decrease in proliferation. Altogether, the results indicate that proliferation might represent a predictive factor for increased Bev sensitivity, which may aid in the identification of patients who could potentially benefit from Bev.

Recruitment of Intratumoral CD103+ Dendritic Cells by a CXCR4 Antagonist-Armed Virotherapy Enhances Antitumor Immunity

Intratumoral dendritic cells play an important role in stimulating cytotoxic T cells and driving antitumor immunity. Using a metastatic ovarian tumor model in syngeneic mice, we explored whether therapy with a CXCR4 antagonist-armed oncolytic vaccinia virus activates endogenous CD103+ dendritic cell responses associated with the induction of adaptive immunity against viral and tumor antigens. The overall goal of this study was to determine whether expansion of CD103+ dendritic cells by the virally delivered CXCR4 antagonist augments overall survival and in situ boosting with a tumor antigen peptide-based vaccine. We found that locoregional delivery of the CXCR4-A-armed virus reduced the tumor load and the immunosuppressive network in the tumor microenvironment, leading to infiltration of CD103+ dendritic cells that were capable of phagocytic clearance of cellular material from virally infected cancer cells. Further expansion of tumor-resident CD103+ DCs by injecting the FMS-related tyrosine kinase 3 ligand, the formative cytokine for CD103+ DCs, provided a platform for a booster immunization with the Wilms tumor antigen 1 peptide-based vaccine delivered intraperitoneally with polyriboinosinic:polyribocytidylic acid as an adjuvant. The vaccine-induced antitumor responses inhibited tumor growth and increased overall survival, indicating that expansion of intratumoral CD103+ dendritic cells by CXCR4-A-armed oncovirotherapy treatment can potentiate in situ cancer vaccine boosting.

MicroRNAs as Key Regulators of Ovarian Cancers

The tumor microenvironment can be realistically viewed as an active battle ground between the host immune system and the growing tumor cells. This reactive space surrounding the tumor possesses several possibilities and facilitates the progression of a tumor from a neoplastic stage to that of metastasis. The contemporary approach of understanding the cancer biology from a “within the cell” perspective has been largely challenged with complex and intricate “outside the cell” events. Thus understanding the biology of the tumor microenvironment has been of scientific and clinical interest. Small non-coding microRNAs with a pleotropic and wide range of cellular gene targets can be reasonably hypothesized to regulate the events of carcinogenesis and progression. MicroRNAs have been investigated in different cancer models, and evidence of their involvement in the regulation of the tumor microenvironment has been of much interest. In particular, a major interest has been exploring the role of the tumor microenvironment in regulating the interaction of cancer cells with surrounding stromal components and the effect of such interactions on the cancer cells. Fine-tuned regulation by these microRNAs extends our contemporary understanding of these small biomolecules in epigenetic regulations. This review focuses on microRNAs that are dysregulated in ovarian carcinomas, their effect on the components of the tumor microenvironment, and the correlation of their heterogeneous expression profiles with disease severity and prognosis in patients. In addition, this paper also discusses the differential expression of exosomal microRNAs that are known to link the cancer cell with its microenvironment, facilitating the development of an improved prognostic/diagnostic marker and effective therapeutic regime.

The Role of Cancer Stem Cells and Mechanical Forces in Ovarian Cancer Metastasis

Ovarian cancer is an extremely lethal gynecologic disease; with the high-grade serous subtype predominantly associated with poor survival rates. Lack of early diagnostic biomarkers and prevalence of post-treatment recurrence, present substantial challenges in treating ovarian cancers. These cancers are also characterized by a high degree of heterogeneity and protracted metastasis, further complicating treatment. Within the ovarian tumor microenvironment, cancer stem-like cells and mechanical stimuli are two underappreciated key elements that play a crucial role in facilitating these outcomes. In this review article, we highlight their roles in modulating ovarian cancer metastasis. Specifically, we outline the clinical relevance of cancer stem-like cells, and challenges associated with their identification and characterization and summarize the ways in which they modulate ovarian cancer metastasis. Further, we review the mechanical cues in the ovarian tumor microenvironment, including, tension, shear, compression and matrix stiffness, that influence (cancer stem-like cells and) metastasis in ovarian cancers. Lastly, we outline the challenges associated with probing these important modulators of ovarian cancer metastasis and provide suggestions for incorporating these cues in basic biology and translational research focused on metastasis. We conclude that future studies on ovarian cancer metastasis will benefit from the careful consideration of mechanical stimuli and cancer stem cells, ultimately allowing for the development of more effective therapies.

Recent Advances of Small Molecular Regulators Targeting G Protein- Coupled Receptors Family for Oncology Immunotherapy

The great clinical success of chimeric antigen receptor T cell (CAR-T) and PD-1/PDL-1 inhibitor therapies suggests the drawing of a cancer immunotherapy age. However, a considerable proportion of cancer patients currently receive little benefit from these treatment modalities, indicating that multiple immunosuppressive mechanisms exist in the tumor microenvironment. In this review, we mainly discuss recent advances in small molecular regulators targeting G Protein-Coupled Receptors (GPCRs) that are associated with oncology immunomodulation, including chemokine receptors, purinergic receptors, prostaglandin E receptor EP4 and opioid receptors. Moreover, we outline how they affect tumor immunity and neoplasia by regulating immune cell recruitment and modulating tumor stromal cell biology. We also summarize the data from recent clinical advances in small molecular regulators targeting these GPCRs, in combination with immune checkpoints blockers, such as PD-1/PDL-1 and CTLA4 inhibitors, for cancer treatments.

CXCL12 is associated with FoxP3+ tumor-infiltrating lymphocytes and affects the survival of patients with oral squamous cell carcinoma

The role of tumor-infiltrating lymphocytes (TILs) suggests that cancer is a disease with not only a genetic, but also an immunological basis. Additionally, immune cell infiltration is an important feature of oral cancer. C-X-C motif chemokine ligand 12 (CXCL12) serves an important role in immune suppression in the tumor microenvironment. Therefore, the present study investigated how CXCL12 expression in oral squamous cell carcinoma (OSCC) was associated with clinicopathological parameters and TILs distribution. Complete CXCL12, TIL and clinical data were available for 45 patients with oral cancer treated by surgery. Expression levels of CXCL12, CD8⁺ TILs and forkhead box P3 (FoxP3⁺) TILs were assessed by immunohistochemistry in OSCC samples. CXCL12 expression in OSCC cells was observed in 32 (68.9%) cases and was associated with poor differentiation (P=0.045), advanced stages (P<0.001), tumor recurrence (P=0.011), poor overall survival (P=0.0476) and a higher density of FoxP3⁺ TILs (P<0.001). The CD8⁺/FoxP3⁺ ratio was lower in patients with poor differentiation (P=0.034), advanced stage tumors (P=0.015) and tumor recurrence (P=0.002). In addition, the ratio of CD8⁺/FoxP3⁺ TILs was significantly associated with the 5-year overall survival rate (P<0.001). The CD8⁺/FoxP3⁺ ratio was indicated to be a stronger prognostic indicator compared with the density of FoxP3⁺ TILs or CD8⁺ TILs. The present study identified an association between increased CXCL12 expression and FoxP3⁺ cell infiltration in OSCC. Targeting the CXCL12/C-X-C motif chemokine receptor 4 axis in OSCC may be employed as a novel strategy of tumor immunotherapy in the future.

Mast Cells, Angiogenesis and Lymphangiogenesis in Human Gastric Cancer

Gastric cancer is diagnosed in nearly one million new patients each year and it remains the second leading cause of cancer-related deaths worldwide. Although gastric cancer represents a heterogeneous group of diseases, chronic inflammation has been shown to play a role in tumorigenesis. Cancer development is a multistep process characterized by genetic and epigenetic alterations during tumour initiation and progression. The stromal microenvironment is important in maintaining normal tissue homeostasis or promoting tumour development. A plethora of immune cells (i.e., lymphocytes, macrophages, mast cells, monocytes, myeloid-derived suppressor cells, Treg cells, dendritic cells, neutrophils, eosinophils, natural killer (NK) and natural killer T (NKT) cells) are components of gastric cancer microenvironment. Mast cell density is increased in gastric cancer and there is a correlation with angiogenesis, the number of metastatic lymph nodes and the survival of these patients. Mast cells exert a protumorigenic role in gastric cancer through the release of angiogenic (VEGF-A, CXCL8, MMP-9) and lymphangiogenic factors (VEGF-C and VEGF-F). Gastric mast cells express the programmed death ligands (PD-L1 and PD-L2) which are relevant as immune checkpoints in cancer. Several clinical undergoing trials targeting immune checkpoints could be an innovative therapeutic strategy in gastric cancer. Elucidation of the role of subsets of mast cells in different human gastric cancers will demand studies of increasing complexity beyond those assessing merely mast cell density and microlocalization.

Mozobil® (Plerixafor, AMD3100), 10 years after its approval by the US Food and Drug Administration

AMD3100 (plerixafor, Mozobil®) was first identified as an anti-HIV agent specifically active against the T4-lymphotropic HIV strains, as it selectively blocked the CXCR4 receptor. Through interference with the interaction of CXCR4 with its natural ligand, SDF-1 (also named CXCL12), it also mobilized the CD34⁺stem cells from the bone marrow into the peripheral blood stream. In December 2008, AMD3100 was formally approved by the US FDA for autologous transplantation in patients with Non-Hodgkin’s Lymphoma or multiple myeloma. It may be beneficially used in various other malignant diseases as well as hereditary immunological disorders such as WHIM syndrome, and physiopathological processes such as hepatopulmonary syndrome.

Concentration of stromal cell-derived factor-1 (SDF-1/CXCL12) in the follicular fluid is associated with blastocyst development

PURPOSE

To study the association between stromal cell-derived factor-1 (SDF-1/CXCL12) and vascular endothelial growth factor (VEGF) concentrations in individual human ovarian follicles and IVF outcomes.

METHODS

Concentrations of SDF-1 and VEGF in 261 follicular fluid samples were measured with enzyme-linked immunosorbent assay. IVF outcome parameters were included in fertilization rate, cleavage rate, embryo morphology on day 3, and blastocyst morphology on day 5.

RESULTS

The follicular concentration of SDF-1 and VEGF was not significantly associated with fertilization and cleavage outcome, and embryo morphology. The rates of full blastocysts and good-quality blastocysts were significantly higher in follicles with an SDF-1 concentration of 275-350 pg/mL than in the follicles with SDF-1 concentrations of <200 and ≥350 pg/mL (P < 0.05). The follicular concentration of VEGF was not associated with the blastocyst morphology.

CONCLUSION

Our findings showed that follicular concentration of SDF-1, and not VEGF, may be a valuable biochemical marker of blastocyst development.

Mast cells: A double-edged sword in cancer

Mast cells (MCs), a type of innate immune cells, are derived from myeloid stem cells, sometimes known as mastocytes or labrocytes, and contain many granules rich in histamine and heparin. The mentioned cells are able to release various mediators such as cytokines, leukotrienes, and a large number of proteases into the environment. Many studies and experiments have established the infiltration of MCs into the tumor site. However, the findings are highly controversial to determine whether these immune cells contribute to the growth and development of the tumor or cause anti-tumor immune responses. Various studies have revealed that MCs have a pro-tumorigenic or anti-tumorigenic role depending on the type of cancer, the degree of tumor progression, and the location of these immune cells in the tumor bulk. Although these types of immune cells cause angiogenesis and tumor progression in some cancers, they have a significant anti-tumor role in some other types of cancers. In general, although a number of studies have specified the protective role of MCs in cancers, the increased number of MCs in the blood and microenvironment of tumors, as well as the increased level of angiogenesis and tumor progression, has been indicated in another array of studies. The function of MCs against or in favor of the cancers still requires further investigations to more accurately and specifically determine the role of MCs in the cancers. The function of MCs in tumors and their various roles in case of exposure to the cancer cells have been addressed in the present review. The concluding section of the present study recommends a number of methods for modification of MCs in cancer immunotherapy.

Chemokines and Chemokine Receptors: New Targets for Cancer Immunotherapy

Immunotherapy is a clinically validated treatment for many cancers to boost the immune system against tumor growth and dissemination. Several strategies are used to harness immune cells: monoclonal antibodies against tumor antigens, immune checkpoint inhibitors, vaccination, adoptive cell therapies (e.g., CAR-T cells) and cytokine administration. In the last decades, it is emerging that the chemokine system represents a potential target for immunotherapy. Chemokines, a large family of cytokines with chemotactic activity, and their cognate receptors are expressed by both cancer and stromal cells. Their altered expression in malignancies dictates leukocyte recruitment and activation, angiogenesis, cancer cell proliferation, and metastasis in all the stages of the disease. Here, we review first attempts to inhibit the chemokine system in cancer as a monotherapy or in combination with canonical or immuno-mediated therapies. We also provide recent findings about the role in cancer of atypical chemokine receptors that could become future targets for immunotherapy.

Targeting the Post-Irradiation Tumor Microenvironment in Glioblastoma via Inhibition of CXCL12

Radiotherapy is a mainstay in glioblastoma therapy as it not only directly targets tumor cells but also depletes the tumor microvasculature. The resulting intra-tumoral hypoxia initiates a chain of events that ultimately leads to re-vascularization, immunosuppression and, ultimately, tumor-regrowth. The key component of this cascade is overexpression of the CXC-motive chemokine ligand 12 (CXCL12), formerly known as stromal-cell derived factor 1 (SDF-1). We here review the role of CXCL12 in recruitment of pro-vasculogenic and immunosuppressive cells and give an overview on future and current drugs that target this axis.

Support of Tumor Endothelial Cells by Chemokine Receptors

Tumor-associated vascular endothelium comprises a specialized and diverse group of endothelial cells that, although not cancer themselves, are integral to cancer progression. Targeting the tumor vasculature can have significant efficacy in reducing tumor burden, although loss of efficacy due to acquisition of resistance mechanisms is common. Here we review mechanisms by which tumor endothelial cells (TEC) utilize chemokine receptors to support tumor progression. We illustrate how chemokine receptors support and may serve as functional markers of the diverse TEC population. We focus on ACKR1 (DARC), ACKR3 (CXCR7), CXCR4, and CCR2, as these are the best studied chemokine receptors in TEC; and suggest that targeting these receptors on the tumor vasculature may prove efficacious in slowing or reversing tumor growth. We also mention CXCR2 and CXCR3 as important mediators or tumor angiogenesis, given their distinct roles with angiogenic and angiostatic chemokines, respectively.

CCL27/CCL28-CCR10 Chemokine Signaling Mediates Migration of Lymphatic Endothelial Cells

Metastasis via the lymphatic vasculature is an important step in cancer progression. The formation of new lymphatic vessels (lymphangiogenesis), or remodeling of existing lymphatics, is thought to facilitate the entry and transport of tumor cells into lymphatic vessels and on to distant organs. The migration of lymphatic endothelial cells (LEC) toward guidance cues is critical for lymphangiogenesis. While chemokines are known to provide directional navigation for migrating immune cells, their role in mediating LEC migration during tumor-associated lymphangiogenesis is not well defined. Here, we undertook gene profiling studies to identify chemokine-chemokine receptor pairs that are involved in tumor lymphangiogenesis associated with lymph node metastasis. CCL27 and CCL28 were expressed in tumor cells with metastatic potential, while their cognate receptor, CCR10, was expressed by LECs and upregulated by the lymphangiogenic growth factor VEGFD and the proinflammatory cytokine TNFα. Migration assays demonstrated that LECs are attracted to both CCL27 and CCL28 in a CCR10-dependent manner, while abnormal lymphatic vessel patterning in CCR10-deficient mice confirmed the significant role of CCR10 in lymphatic patterning. In vivo analyses showed that LECs are recruited to a CCL27 or CCL28 source, while VEGFD was required in combination with these chemokines to enable formation of coherent lymphatic vessels. Moreover, tumor xenograft experiments demonstrated that even though CCL27 expression by tumors enhanced LEC recruitment, the ability to metastasize was dependent on the expression of VEGFD. These studies demonstrate that CCL27 and CCL28 signaling through CCR10 may cooperate with inflammatory mediators and VEGFD during tumor lymphangiogenesis. SIGNIFICANCE: The study shows that the remodeling of lymphatic vessels in cancer is influenced by CCL27 and CCL28 chemokines, which may provide a future target to modulate metastatic spread.

A Unique Collateral Artery Development Program Promotes Neonatal Heart Regeneration

Collateral arteries are an uncommon vessel subtype that can provide alternate blood flow to preserve tissue following vascular occlusion. Some patients with heart disease develop collateral coronary arteries, and this correlates with increased survival. However, it is not known how these collaterals develop or how to stimulate them. We demonstrate that neonatal mouse hearts use a novel mechanism to build collateral arteries in response to injury. Arterial endothelial cells (ECs) migrated away from arteries along existing capillaries and reassembled into collateral arteries, which we termed "artery reassembly". Artery ECs expressed CXCR4, and following injury, capillary ECs induced its ligand, CXCL12. CXCL12 or CXCR4 deletion impaired collateral artery formation and neonatal heart regeneration. Artery reassembly was nearly absent in adults but was induced by exogenous CXCL12. Thus, understanding neonatal regenerative mechanisms can identify pathways that restore these processes in adults and identify potentially translatable therapeutic strategies for ischemic heart disease.

Hypoxia-Dependent Angiogenesis and Lymphangiogenesis in Cancer

Hypoxia (low O₂) is a ubiquitous feature of solid cancers, arising as a mismatch between cellular O₂ supply and consumption. Hypoxia is associated to metastatic disease and mortality owing to its ability to stimulate the formation of blood (angiogenesis) and lymphatic vessels (lymphangiogenesis), thereby allowing cancer cells to escape the unfavorable tumor microenvironment and disseminate into secondary sites. This review outlines molecular mechanisms by which intratumoral hypoxia regulates the expression of motogenic and mitogenic factors that induce angiogenesis and lymphangiogenesis, whilst discussing their implications for metastatic cancers.

Beneficial effects of sunitinib on tumor microenvironment and immunotherapy targeting death receptor5

Tumor-associated blood vessels and lymphatics are abnormal and dysfunctional. These are hallmarks of the tumor microenvironment, which has an immunosuppressive nature, such as through hypoxia. Treatment with anti-death receptor5 (DR5) monoclonal antibody MD5-1, which induces tumor cell death, is a potent anti-tumor immunotherapy. Generally, MD5-1 induces cell death mainly via antigen presenting cells (APCs) and generates tumor-specific effector T cells. To date, the effects of a simultaneous functional improvement of abnormal blood vessels and lymphatics on the immune microenvironment are largely unknown. A combination therapy using sunitinib, vascular endothelial growth factor (VEGF) and platelet-derived growth factor receptor inhibitor, and MD5-1 substantially inhibited tumor growth. Sunitinib improved pericyte coverage on endothelial cells and the expression levels of regulator of G-protein signaling 5, suggesting blood vessel normalization. Sunitinib also increased lymph flow from tumors to central lymph nodes, suggesting improved lymphatic function. In concordance with improved vasculature functions, sunitinib alleviated the tumor hypoxia, suggesting an improved tumor microenvironment. Indeed, the combination therapy induced strong activation of CD8⁺ T cells and dendritic cells in draining lymph nodes. The combination therapy reduced the ratio of immune-suppressive T regulatory cells in the tumors and draining lymph nodes. The combination therapy enhanced the numbers and activation of tumor-infiltrating CD8⁺ T cells. CD4 and/or CD8 depletion, or APC inhibiting experiments showed the contribution of CD8⁺ T cells and APCs to the combination therapy. These findings suggest that targeting blood vessels and lymphatics may have potential benefits for immunotherapy mediated by CD8⁺ T cells and APCs.

Pathological roles of the homeostatic chemokine CXCL12

CXCL12 is a CXC chemokine that traditionally has been classified as a homeostatic chemokine. It contributes to physiological processes such as embryogenesis, hematopoiesis and angiogenesis. In contrast to these homeostatic functions, increased expression of CXCL12 in general, or of a specific CXCL12 splicing variant has been demonstrated in various pathologies. In addition to this increased or differential transcription of CXCL12, also upregulation of its receptors CXC chemokine receptor 4 (CXCR4) and atypical chemokine receptor 3 (ACKR3) contributes to the onset or progression of diseases. Moreover, posttranslational modification of CXCL12 during disease progression, through interaction with locally produced molecules or enzymes, also affects CXCL12 activity, adding further complexity. As CXCL12, CXCR4 and ACKR3 are broadly expressed, the number of pathologies wherein CXCL12 is involved is growing. In this review, the role of the CXCL12/CXCR4/ACKR3 axis will be discussed for the most prevalent pathologies. Administration of CXCL12-neutralizing antibodies or small-molecule antagonists of CXCR4 or ACKR3 delays disease onset or prevents disease progression in cancer, viral infections, inflammatory bowel diseases, rheumatoid arthritis and osteoarthritis, asthma and acute lung injury, amyotrophic lateral sclerosis and WHIM syndrome. On the other hand, CXCL12 has protective properties in Alzheimer's disease and multiple sclerosis, has a beneficial role in wound healing and has crucial homeostatic properties in general.

The Role of Inflammation and Inflammatory Mediators in the Development, Progression, Metastasis, and Chemoresistance of Epithelial Ovarian Cancer

Inflammation plays a role in the initiation and development of many types of cancers, including epithelial ovarian cancer (EOC) and high grade serous ovarian cancer (HGSC), a type of EOC. There are connections between EOC and both peritoneal and ovulation-induced inflammation. Additionally, EOCs have an inflammatory component that contributes to their progression. At sites of inflammation, epithelial cells are exposed to increased levels of inflammatory mediators such as reactive oxygen species, cytokines, prostaglandins, and growth factors that contribute to increased cell division, and genetic and epigenetic changes. These exposure-induced changes promote excessive cell proliferation, increased survival, malignant transformation, and cancer development. Furthermore, the pro-inflammatory tumor microenvironment environment (TME) contributes to EOC metastasis and chemoresistance. In this review we will discuss the roles inflammation and inflammatory mediators play in the development, progression, metastasis, and chemoresistance of EOC.

Laminin α1 orchestrates VEGFA functions in the ecosystem of colorectal carcinoma

BACKGROUND INFORMATION

Tumor stroma remodeling is a key feature of malignant tumors and can promote cancer progression. Laminins are major constituents of basement membranes that physically separate the epithelium from the underlying stroma.

RESULTS

By employing mouse models expressing high and low levels of the laminin α1 chain (LMα1), we highlighted its implication in a tumor-stroma crosstalk, thus leading to increased colon tumor incidence, angiogenesis and tumor growth. The underlying mechanism involves attraction of carcinoma-associated fibroblasts by LMα1, VEGFA expression triggered by the complex integrin α2β1-CXCR4 and binding of VEGFA to LM-111, which in turn promotes angiogenesis, tumor cell survival and proliferation. A gene signature comprising LAMA1, ITGB1, ITGA2, CXCR4 and VEGFA has negative predictive value in colon cancer.

CONCLUSIONS

Together, we have identified VEGFA, CXCR4 and α2β1 integrin downstream of LMα1 in colon cancer as of bad prognostic value for patient survival.

SIGNIFICANCE

This information opens novel opportunities for diagnosis and treatment of colon cancer.

Nrf2 protects against diabetic dysfunction of endothelial progenitor cells via regulating cell senescence

Diabetes is associated with an increased risk of cardio-vascular disease. A decrease in the number and functionality of endothelial progenitor cells (EPCs) leads to reduced endothelial repair and the development of cardiovascular disease. The aim of the present study was to explore the effect and underlying mechanisms of nuclear factor erythroid 2-related factor 2 (Nrf2) on EPC dysfunction caused by diabetic mellitus. The biological functions of EPCs in streptozotocin-induced diabetic mice were evaluated, including migration, proliferation, angiogenesis and the secretion of vascular endothelial growth factor (VEGF), stromal-derived growth factor (SDF) and nitric oxide (NO). Oxidative stress levels in diabetic EPCs were also assessed by detecting intracellular reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA). EPC senescence was evaluated by measuring p16 and b-gal expression and observing the senescence-associated secretory phenotype. In addition, the function of EPCs and level of oxidative stress were assessed following Nrf2 silencing or activation. Nrf2 silencing resulted in a decrease of EPC biological functions, accelerated cell senescence and increased oxidative stress, as indicated by ROS and MDA upregulation accompanied with decreased SOD activity. Furthermore, Nrf2 silencing inhibited migration, proliferation and secretion in EPCs, while it increased oxidative stress and cell senescence. Nrf2 activation protected diabetic EPCs against the effects of oxidative stress and cell senescence, ameliorating the biological dysfunction of EPCs derived from mice with diabetes. In conclusion, Nrf2 overexpression protected against oxidative stress-induced functional damage in EPCs derived from diabetic mice by regulating cell senescence.

Chemokines in homeostasis and diseases

For the past twenty years, chemokines have emerged as a family of critical mediators of cell migration during immune surveillance, development, inflammation and cancer progression. Chemokines bind to seven transmembrane G protein-coupled receptors (GPCRs) that are expressed by a wide variety of cell types and cause conformational changes in trimeric G proteins that trigger the intracellular signaling pathways necessary for cell movement and activation. Although chemokines have evolved to benefit the host, inappropriate regulation or utilization of these small proteins may contribute to or even cause diseases. Therefore, understanding the role of chemokines and their GPCRs in the complex physiological and diseased microenvironment is important for the identification of novel therapeutic targets. This review introduces the functional array and signals of multiple chemokine GPCRs in guiding leukocyte trafficking as well as their roles in homeostasis, inflammation, immune responses and cancer.

miR200-regulated CXCL12β promotes fibroblast heterogeneity and immunosuppression in ovarian cancers

High-grade serous ovarian cancers (HGSOC) have been subdivided into molecular subtypes. The mesenchymal HGSOC subgroup, defined by stromal-related gene signatures, is invariably associated with poor patient survival. We demonstrate that stroma exerts a key function in mesenchymal HGSOC. We highlight stromal heterogeneity in HGSOC by identifying four subsets of carcinoma-associated fibroblasts (CAF-S1-4). Mesenchymal HGSOC show high content in CAF-S1 fibroblasts, which exhibit immunosuppressive functions by increasing attraction, survival, and differentiation of CD25⁺FOXP3⁺ T lymphocytes. The beta isoform of the CXCL12 chemokine (CXCL12β) specifically accumulates in the immunosuppressive CAF-S1 subset through a miR-141/200a dependent-mechanism. Moreover, CXCL12β expression in CAF-S1 cells plays a crucial role in CAF-S1 immunosuppressive activity and is a reliable prognosis factor in HGSOC, in contrast to CXCL12α. Thus, our data highlight the differential regulation of the CXCL12α and CXCL12β isoforms in HGSOC, and reveal a CXCL12β-associated stromal heterogeneity and immunosuppressive environment in mesenchymal HGSOC.

Expression of CXC-motif-chemokine 12 and the receptor C-X-C receptor 4 in glioma and theeffect on peritumoral brain edema

The present study aimed to evaluate the association between CXC-motif-chemokine 12 (CXCL12)/C-X-C receptor 4 (CXCR4) expression and peritumoral brain edema (PTBE) in glioma patients. Immunohistochemical techniques were used to detect the expression of CXCR4 and CXCL12 in 58 glioma tissues. Magnetic resonance imaging was used to evaluate the extent and type of brain edema in preoperative glioma patients. The association between edema and CXCL12/CXCR4 expression was examined by χ² analysis. The prognostic significance of CXCL12 or CXCR4 was determined by log-rank tests and Cox's proportional hazards model. Expression of CXCL12 and CXCR4 was observed in vascular endothelial cells and tumor cells. The degree (P=0.033) and morphology (P=0.033) of PTBE were significantly associated with the level of CXCL12 expression in vascular endothelial cells. The degree (P=0.001) and morphology (P=0.001) of PTBE were associated with the level of CXCR4 expression in tumor cells. CXCR4-positive vascular endothelial cells were significantly associated only with the degree of edema (P=0.030). Therefore, the present study indicated that levels of CXCL12 expression in vascular endothelial cells and CXCR4 expression in tumor cells are associated with PTBE.

Breast cancer metastasis to liver and lung is facilitated by Pit-1-CXCL12-CXCR4 axis

Development of human tumors is driven by accumulation of alterations in tumor suppressor genes and oncogenes in cells. The POU1F1 transcription factor (also known Pit-1) is expressed in the mammary gland and its overexpression induces profound phenotypic changes in proteins involved in breast cancer progression. Patients with breast cancer and elevated expression of Pit-1 show a positive correlation with the occurrence of distant metastasis and poor overall survival. However, some mediators of Pit-1 actions are still unknown. Here, we show that CXCR4 chemokine receptor and its ligand CXCL12 play a critical role in the pro-tumoral process induced by Pit-1. We found that Pit-1 increases mRNA and protein in both CXCR4 and CXCL12. Knock-down of CXCR4 reduces tumor growth and spread of Pit-1 overexpressing cells in a zebrafish xenograft model. Furthermore, we described for the first time pro-angiogenic effects of Pit-1 through the CXCL12-CXCR4 axis, and that extravasation of Pit-1 overexpressing breast cancer cells is strongly reduced in CXCL12-deprived target tissues. Finally, in breast cancer patients, expression of Pit-1 in primary tumors was found to be positively correlated with CXCR4 and CXCL12, with specific metastasis in liver and lung, and with clinical outcome. Our results suggest that Pit-1-CXCL12-CXCR4 axis could be involved in chemotaxis guidance during the metastatic process, and may represent prognostic and/or therapeutic targets in breast tumors.

G Protein-Coupled Receptors at the Crossroad between Physiologic and Pathologic Angiogenesis: Old Paradigms and Emerging Concepts

G protein-coupled receptors (GPCRs) have been implicated in transmitting signals across the extra- and intra-cellular compartments, thus allowing environmental stimuli to elicit critical biological responses. As GPCRs can be activated by an extensive range of factors including hormones, neurotransmitters, phospholipids and other stimuli, their involvement in a plethora of physiological functions is not surprising. Aberrant GPCR signaling has been regarded as a major contributor to diverse pathologic conditions, such as inflammatory, cardiovascular and neoplastic diseases. In this regard, solid tumors have been demonstrated to activate an angiogenic program that relies on GPCR action to support cancer growth and metastatic dissemination. Therefore, the manipulation of aberrant GPCR signaling could represent a promising target in anticancer therapy. Here, we highlight the GPCR-mediated angiogenic function focusing on the molecular mechanisms and transduction effectors driving the patho-physiological vasculogenesis. Specifically, we describe evidence for the role of heptahelic receptors and associated G proteins in promoting angiogenic responses in pathologic conditions, especially tumor angiogenesis and progression. Likewise, we discuss opportunities to manipulate aberrant GPCR-mediated angiogenic signaling for therapeutic benefit using innovative GPCR-targeted and patient-tailored pharmacological strategies.

Molecular Regulation of Sprouting Angiogenesis

The term angiogenesis arose in the 18th century. Several studies over the next 100 years laid the groundwork for initial studies performed by the Folkman laboratory, which were at first met with some opposition. Once overcome, the angiogenesis field has flourished due to studies on tumor angiogenesis and various developmental models that can be genetically manipulated, including mice and zebrafish. In addition, new discoveries have been aided by the ability to isolate primary endothelial cells, which has allowed dissection of various steps within angiogenesis. This review will summarize the molecular events that control angiogenesis downstream of biochemical factors such as growth factors, cytokines, chemokines, hypoxia-inducible factors (HIFs), and lipids. These and other stimuli have been linked to regulation of junctional molecules and cell surface receptors. In addition, the contribution of cytoskeletal elements and regulatory proteins has revealed an intricate role for mobilization of actin, microtubules, and intermediate filaments in response to cues that activate the endothelium. Activating stimuli also affect various focal adhesion proteins, scaffold proteins, intracellular kinases, and second messengers. Finally, metalloproteinases, which facilitate matrix degradation and the formation of new blood vessels, are discussed, along with our knowledge of crosstalk between the various subclasses of these molecules throughout the text. Compr Physiol 8:153-235, 2018.