p53-dependent expression of CXCR5 chemokine receptor in MCF-7 breast cancer cells

Novel photocrosslinking chemical probes utilized for high-resolution spatial transcriptomics

The architecture of cells and the tissue they form within multicellular organisms are highly complex and dynamic. Cells optimize their function within tissue microenvironments by expressing specific subsets of RNAs. Advances in cell tagging methods enable spatial understanding of RNA expression when merged with transcriptomics. However, these techniques are currently limited by the spatial resolution of the tagging, the number of RNAs that can be sequenced, and multiplexing to isolate spatially-distinct cells within the same tissue landscape. To address these limitations, we developed CrossSeq, which employs photocrosslinking fluorescent probes and confocal microscopy activation to demarcate user-defined regions of interest on fixed cells for multiplexed spatial transcriptomic analysis. We investigate phenyl azide and diazirine crosslinking scaffolds and define their photoactivity profiles. We then deploy the aryl azide scaffold with three fluorophores for multiplexing on glyoxal fixed cells and analyze the defined populations using flow cytometry. Finally, we apply CrossSeq to investigate an in vitro MDA-MB-231-LM2 metastatic cancer migration model to evaluate changes in gene expression at the migratory cell front versus the exterior population. We anticipate this new technology will be a valuable tool addition as it will enable easier access to spatial transcriptomic analysis for the scientific community using conventional microscopy and analysis techniques.

AXL/GAS6 signaling governs differentiation of tumor-associated macrophages in breast cancer

Most epithelial cancers are infiltrated by prognostically relevant myelomonocytic cells. Immunosuppressive tumor associated macrophages (TAMs) and their precursor monocytic myeloid-derived suppressor cells (MDSCs) have previously been associated with worse outcomes in human breast cancer (BCa), yet the mechanism of immunosuppressive TAMs-polarization from myelomonocytic precursors is not completely understood. In this study, we show that persuaded AXL/GAS6 pathway alters macrophage phenotype from HLA-DRhighCD206lowCD163low classical phagocytic into HLA-DRlowCD206highCD163high immunosuppressive ones with accelerated BCa progression, and increased angiogenesis signature and invasion ability of cancer cells at tumor beds. Notably, both AXL and GAS6 expressions are upregulated in human invasive breast carcinoma, with maximum expression in triple negative histology type. Mechanistically, we demonstrate that AXL/GAS6 signaling drives immunosuppression by governing increased immunosuppressive IL10 production while dampening IL-1β expression within the tumor microenvironment (TME) of BCa. Further, AXL/GAS6 signaling promotes angiogenesis through the activation of PI3K/AKT and NF-κB signaling pathways. Our results unveil role of AXL/GAS6 axis in the differentiation of TAMs, which governs malignant growth, and suggest that therapies that uncouple AXL/GAS6 axis may exhibit therapeutic opportunity for otherwise undruggable Triple Negative Breast Cancer (TNBC) patients.

Revisiting the CXCL13/CXCR5 axis in the tumor microenvironment in the era of single-cell omics: Implications for immunotherapy

As one of the important members of the family of chemokines and their receptors, the CXCL13/CXCR5 axis is involved in follicle formation in normal lymphoid tissues and the establishment of somatic cavity immunity under physiological conditions, as well as being associated with a wide range of infectious, autoimmune, and tumoral diseases. Here in this review, we focus on its role in tumors. Traditional studies have found the axis to be both pro- and anti-tumorigenic, involving a variety of immune cells, including the tumor cells themselves and those in the tumor microenvironment (TME), and the prognostic significance of this axis is clinical context-dependent. With the development of techniques at the single-cell level, we were able to explain in detail the status of the CXCL13/CXCR5 axis in the TME based on real clinical samples and found that it involves a range of crucial intrinsic anti-tumor immune processes in the TME and is therefore important in tumor immunotherapy. We summarize the cellular subsets, physiological functions, and prognostic significance associated with this axis in the most promising immune checkpoint inhibitor (ICI) therapies of the day and summarize possible therapeutic ideas based on this axis. As with any TME study, the most important takeaway is that the complexity of the CXCL13/CXCR5 axis in TME suggests the importance of personalized therapy in tumor therapy.

B cell responses and antibody-based therapeutic perspectives in human cancers

BACKGROUND

Immuno-oncology has been focused on T cell-centric approaches until the field recently started appreciating the importance of tumor-reactive antibody production by tumor-infiltrating plasma B cells, and the necessity of developing novel therapeutic antibodies for the treatment of different cancers.

RECENT FINDINGS

B lymphocytes often infiltrate solid tumors and the extent of B cell infiltration normally correlates with stronger T cell responses while generating humoral responses against malignant progression by producing tumor antigens-reactive antibodies that bind and coat the tumor cells and promote cytotoxic effector mechanisms, reiterating the fact that the adaptive immune system works by coordinated humoral and cellular immune responses. Isotypes, magnitude, and the effector functions of antibodies produced by the B cells within the tumor environment differ among cancer types. Interestingly, apart from binding with specific tumor antigens, antibodies produced by tumor-infiltrating B cells could bind to some non-specific receptors, peculiarly expressed by cancer cells. Antibody-based immunotherapies have revolutionized the modalities of cancer treatment across the world but are still limited against hematological malignancies and a few types of solid tumor cancers with a restricted number of targets, which necessitates the expansion of the field to have newer effective targeted antibody therapeutics.

CONCLUSION

Here, we discuss about recent understanding of the protective spontaneous antitumor humoral responses in human cancers, with an emphasis on the advancement and future perspectives of antibody-based immunotherapies in cancer.

Potential molecular mechanisms of myrtenal against colon cancer: A systematic review

Colon cancer is a serious health problem across the globe with various dietary lifestyle modifications. It arises as an inflammation mediated crypts in the colon epithelial cells and undergoes uncontrolled cell division and proliferation. Bacterial enzymes contribute to a major outbreak in colon cancer development upon the release of toxic metabolites from the gut microflora. Pathogen associated molecular patterns and damage associated molecular patterns triggers the NLPR3 inflammasome pathways that releases pro-inflammatory cytokines to induce cancer of the colon. Contributing to this, specific chemokines and receptor complexes attribute to cellular proliferation and metastasis. Bacterial enzymes synergistically attack the colon mucosa and degenerate the cellular integrity causing lysosomal discharge. These factors further instigate the Tol like receptors (TLRs) and Nod like receptors (NLRs) to promote angiogenesis and supply nutrients for the cancer cells. Myrtenal, a monoterpene, is gaining more importance in recent times and it is being widely utilized against many diseases such as cancers, neurodegenerative diseases and diabetes. Based on the research data's, the reviews focus on the anticancer property of myrtenal by emphasizing its therapeutic properties which downregulate the inflammasome pathways and other signalling pathways. Combination therapy is gaining more importance as they can target every variant in the cellular stress condition. Clinical studies with compounds like myrtenal of the monoterpenes family is provided with positive results which might open an effective anticancer drug therapy. This review highlights myrtenal and its biological potency as a cost effective drug for prevention and treatment of colon cancer.

Osteoid cell-derived chemokines drive bone-metastatic prostate cancer

One of the greatest challenges in improving prostate cancer (PCa) survival is in designing new therapies to effectively target bone metastases. PCa regulation of the bone environment has been well characterized; however, bone-targeted therapies have little impact on patient survival, demonstrating a need for understanding the complexities of the tumor-bone environment. Many factors contribute to creating a favorable microenvironment for prostate tumors in bone, including cell signaling proteins produced by osteoid cells. Specifically, there has been extensive evidence from both past and recent studies that emphasize the importance of chemokine signaling in promoting PCa progression in the bone environment. Chemokine-focused strategies present promising therapeutic options for treating bone metastasis. These signaling pathways are complex, with many being produced by (and exerting effects on) a plethora of different cell types, including stromal and tumor cells of the prostate tumor-bone microenvironment. ​This review highlights an underappreciated molecular family that should be interrogated for treatment of bone metastatic prostate cancer (BM-PCa).

CXCL13-CXCR5 axis: Regulation in inflammatory diseases and cancer

Chemokine C-X-C motif ligand 13 (CXCL13), originally identified as a B-cell chemokine, plays an important role in the immune system. The interaction between CXCL13 and its receptor, the G-protein coupled receptor (GPCR) CXCR5, builds a signaling network that regulates not only normal organisms but also the development of many diseases. However, the precise action mechanism remains unclear. In this review, we discussed the functional mechanisms of the CXCL13-CXCR5 axis under normal conditions, with special focus on its association with diseases. For certain refractory diseases, we emphasize the diagnostic and therapeutic role of CXCL13-CXCR5 axis.

p53: From Fundamental Biology to Clinical Applications in Cancer

p53 tumour suppressor gene is our major barrier against neoplastic transformation. It is involved in many cellular functions, including cell cycle arrest, senescence, DNA repair, apoptosis, autophagy, cell metabolism, ferroptosis, immune system regulation, generation of reactive oxygen species, mitochondrial function, global regulation of gene expression, miRNAs, etc. Its crucial importance is denounced by the high percentage of amino acid sequence identity between very different species (Homo sapiens, Drosophila melanogaster, Rattus norvegicus, Danio rerio, Canis lupus familiaris, Gekko japonicus). Many of its activities allowed life on Earth (e.g., repair from radiation-induced DNA damage) and directly contribute to its tumour suppressor function. In this review, we provide paramount information on p53, from its discovery, which is an interesting paradigm of science evolution, to potential clinical applications in anti-cancer treatment. The description of the fundamental biology of p53 is enriched by specific information on the structure and function of the protein as well by tumour/host evolutionistic perspectives of its role.

Downregulation of TPX2 impairs the antitumor activity of CD8+ T cells in hepatocellular carcinoma

Targeting key genes that play dominant roles in T cell dysfunction is an efficient strategy for cancer immunotherapy. Here, we aimed to investigate the role of TPX2 in the antitumor effect of CD8 + T cells in hepatocellular carcinoma (HCC). Flow cytometry was used to assay the level of cell surface markers and cytokines in T cells, through which we found that TPX2 was downregulated in HCC-infiltrating CD8 + T cells. TPX2 depletion restricted the antitumor activity of CD8 + T cells, and TPX2 overexpression increased the antitumor effect of CD8 + T cells in tumor-bearing Cd8^−/− mice. TPX2 overexpression improved the antitumor function of human CD8 + T cells and response to anti-PD-1 therapy in an HCC patient-derived xenograft (PDX) mouse model with or without anti-PD-1 therapy. In mechanism, TPX2 promotes the phosphorylation of P65, thus increases the level of p-P65 in nuclear, and p-P65 binds to the promoter of CXCR5, activates its transcription, and increases the level of CXCR5 on CD8 + T cells in a TPX2-dependent way. In conclusion, TPX2 maintains the antitumor effect of CD8 + T cells in HCC by regulating CXCR5 via the NF-κB signaling pathway. Increased TPX2 expression in CD8 + T cells exerts synergistic effects with anti-PD-1 therapy, suggesting a promising immunotherapeutic method in HCC.

Inflammatory level under different p53 mutation status and the regulation role of curcumin in tumor microenvironment

The inflammation is tightly associated with tumor development, promoting or inhibiting tumorigenesis. And mutant p53 is speculated to promote inflammation and tumorigenesis. The tumor associated macrophages are usually educated to present the anti-inflammatory profile to tune down antitumor immunity. However, the impact of p53 mutants on macrophages is not clear. Here, we compared the basal inflammatory level and macrophage profiles in tumor cells and tumor samples with different p53 mutations. Data revealed that a lower inflammatory level was maintained in immune organs and tumor cells with p53 point mutations than those with p53 null mutation. Using the tumor cell-derived conditional media to culture macrophages, we found that the media from cells with p53 mutations, especially the point mutations, could decrease M1 markers and inhibit phagocytosis, suggesting the p53 mutation promoted M2 profile polarization. To target the p53 mutation induced M2 macrophage polarization, we applied low-concentration curcumin to the tumor cells with different p53 mutations. The data showed that curcumin could inhibit STAT3 signal and decrease PPARγ and CSF1 in tumor cells and tumor samples. In vitro, the co-culture assays showed that the curcumin treatment shifted p53 mutation educated macrophages back towards M1 profile. In vivo, the curcumin-treated MEFs showed obvious tumor inhibition, and the tumor samples displayed inhibited M2 markers. Results suggested that curcumin could inhibit p53 mutation educated macrophage induction and suppress M2-promoted tumorigenesis. Our study illustrated the inflammatory level under different p53 status and the inflammatory regulated role of curcumin in tumor environment. This study might provide a potential method in tumor personalized treatment aiming immune therapy in different p53 status.

Potential Role of CXCL13/CXCR5 Signaling in Immune Checkpoint Inhibitor Treatment in Cancer

Simple Summary

Immunotherapy is currently the backbone of new drug treatments for many cancer patients. CXC chemokine ligand 13 (CXCL13) is an important factor involved in recruiting immune cells that express CXC chemokine receptor type 5 (CXCR5) in the tumor microenvironment and serves as a key molecular determinant of tertiary lymphoid structure (TLS) formation. An increasing number of studies have identified the influence of CXCL13 on prognosis in patients with cancer, regardless of the use of immunotherapy treatment. However, no comprehensive reviews of the role of CXCL13 in cancer immunotherapy have been published to date. This review aims to provide an overview of the CXCL13/CXCR5 signaling axis to summarize its mechanisms of action in cancer cells and lymphocytes, in addition to effects on immunity and cancer pathobiology, and its potential as a biomarker for the response to cancer immunotherapy.

Abstract

Immune checkpoint inhibitors (ICIs), including antibodies that target programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), or cytotoxic T lymphocyte antigen 4 (CTLA4), represent some of the most important breakthroughs in new drug development for oncology therapy from the past decade. CXC chemokine ligand 13 (CXCL13) exclusively binds CXC chemokine receptor type 5 (CXCR5), which plays a critical role in immune cell recruitment and activation and the regulation of the adaptive immune response. CXCL13 is a key molecular determinant of the formation of tertiary lymphoid structures (TLSs), which are organized aggregates of T, B, and dendritic cells that participate in the adaptive antitumor immune response. CXCL13 may also serve as a prognostic and predictive factor, and the role played by CXCL13 in some ICI-responsive tumor types has gained intense interest. This review discusses how CXCL13/CXCR5 signaling modulates cancer and immune cells to promote lymphocyte infiltration, activation by tumor antigens, and differentiation to increase the antitumor immune response. We also summarize recent preclinical and clinical evidence regarding the ICI-therapeutic implications of targeting the CXCL13/CXCR5 axis and discuss the potential role of this signaling pathway in cancer immunotherapy.

ETV4 promotes pancreatic ductal adenocarcinoma metastasis through activation of the CXCL13/CXCR5 signaling axis

Pancreatic ductal adenocarcinoma (PDAC) has the highest fatality rate of any solid tumor, with a five-year survival rate of only 10% in the USA. PDAC is characterized by early metastasis. More than 50% of patients present with distant metastases at the time of diagnosis, and the majority of patients will develop metastasis within 4 years after tumor resection. Despite extensive studies, the molecular mechanisms underlying PDAC metastasis remain unclear. The polyoma enhancer activator protein (PEA3) subfamily was reported to play a vital role in the initiation and progression of multiple tumors. Herein, we found that ETS variant 4 (ETV4) was highly expressed in PDAC tissues and associated with poor survival. Univariate and multivariate analyses revealed that ETV4 expression was an independent prognostic factor for patient survival. Further experiments showed that ETV4 overexpression promoted PDAC invasion and metastasis both in vitro and in vivo. For the first time, we demonstrated that, mechanistically, ETV4 increased CXCR5 expression by directly binding to the CXCR5 promoter region. Knockdown of CXCR5 significantly reversed ETV4-mediated PDAC migration and invasion, while CXCR5 overexpression exerted the opposite effects. Intriguingly, we found that CXCL13, a specific ligand of CXCR5, increased ETV4 expression and promoted PDAC invasion and metastasis by activating the ERK1/2 pathway. ETV4 knockdown significantly abrogated the enhanced migratory and invasive abilities induced by the CXCL13/CXCR5 axis. In addition, a CXCR5 neutralizing antibody disrupted the CXCL13/ETV4/CXCR5 positive feedback loop and inhibited cell migration and invasion. Overall, in this study, we demonstrated that ETV4 plays a vital role in PDAC metastasis and defined a novel CXCL13/ETV4/CXCR5 positive feedback loop. Targeting this pathway has implications for potential therapeutic strategies for PDAC treatment.

CXCL13 in Cancer and Other Diseases: Biological Functions, Clinical Significance, and Therapeutic Opportunities

The development of cancer is a multistep and complex process involving interactions between tumor cells and the tumor microenvironment (TME). C-X-C chemokine ligand 13 (CXCL13) and its receptor, CXCR5, make crucial contributions to this process by triggering intracellular signaling cascades in malignant cells and modulating the sophisticated TME in an autocrine or paracrine fashion. The CXCL13/CXCR5 axis has a dominant role in B cell recruitment and tertiary lymphoid structure formation, which activate immune responses against some tumors. In most cancer types, the CXCL13/CXCR5 axis mediates pro-neoplastic immune reactions by recruiting suppressive immune cells into tumor tissues. Tobacco smoke and haze (smohaze) and the carcinogen benzo(a)pyrene induce the secretion of CXCL13 by lung epithelial cells, which contributes to environmental lung carcinogenesis. Interestingly, the knockout of CXCL13 inhibits benzo(a)pyrene-induced lung cancer and azoxymethane/dextran sodium sulfate-induced colorectal cancer in mice. Thus, a better understanding of the context-dependent functions of the CXCL13/CXCR5 axis in tumor tissue and the TME is required to design an efficient immune-based therapy. In this review, we summarize the molecular events and TME alterations caused by CXCL13/CXCR5 and briefly discuss the potentials of agents targeting this axis in different malignant tumors.

CXC chemokine ligand-13 promotes metastasis via CXCR5-dependent signaling pathway in non-small cell lung cancer

The CXC chemokine ligand-13 (CXCL13) is a chemoattractant of B cells and has been implicated in the progression of many cancers. So far, CXCL13 and its related receptor CXCR5 have been proved to regulate cancer cell migration as well as tumour metastasis. However, the role of CXCL13-CXCR5 axis in metastasis of lung cancer is still poorly understood. In this study, we found that CXCL13 and CXCR5 were commonly up-regulated in lung cancer specimens compared with normal tissues among different cohorts. Our evidence showed that CXCL13 obviously promoted migration of lung cancer cells, and this effect was mediated by vascular cell adhesion molecule-1 (VCAM-1) expression. We also confirmed that CXCR5, the major receptor responsible for CXCL13 function, was required for CXCL13-promoted cell migration. We also test the candidate components which are activated after CXCL13 treatment and found that phospholipase C-β (PLCβ), protein kinase C-α (PKCα) and c-Src signalling pathways were involved in CXCL13-promoted cell migration and VCAM-1 expression in lung cancer cells. Finally, CXCL13 stimulated NF-κB transcription factor in lung cancer cells, contributing to VCAM-1 expression in translational level. These evidences propose a novel insight into lung cancer metastasis which is regulated by CXCL13.

frDriver: A Functional Region Driver Identification for Protein Sequence

Identifying cancer drivers is a crucial challenge to explain the underlying mechanisms of cancer development. There are many methods to identify cancer drivers based on the single mutation site or the entire gene. But they ignore a large number of functional elements with medium in size. It is hypothesized that mutations occurring in different regions of the protein sequence have different effects on the progression of cancer. Here, we develop a novel functional region driver(frDriver) identification method based on Bayesian probability and multiple linear regression models to identify protein regions that can regulate gene expression levels and have high functional impact potential. Combining gene expression data and somatic mutation data, with functional impact scores(SIFT, PROVEAN) as a priori knowledge, we identified cancer driver regions that are most accurate in predicting gene expression levels. We evaluated the performance of frDriver on the BRCA and GBM datasets from TCGA. The results showed that frDriver identified known cancer drivers and outperformed the other three state-of-the-art methods(eDriver, ActiveDriver and OncodriveCLUST). In addition, we performed KEGG pathway and GO term enrichment analysis, and the results indicated that the cancer drivers predicted by frDriver were related to processes such as cancer formation and gene regulation.

PET Imaging Radiotracers of Chemokine Receptors

Chemokines and chemokine receptors have been recognized as critical signal components that maintain the physiological functions of various cells, particularly the immune cells. The signals of chemokines/chemokine receptors guide various leukocytes to respond to inflammatory reactions and infectious agents. Many chemokine receptors play supportive roles in the differentiation, proliferation, angiogenesis, and metastasis of diverse tumor cells. In addition, the signaling functions of a few chemokine receptors are associated with cardiac, pulmonary, and brain disorders. Over the years, numerous promising molecules ranging from small molecules to short peptides and antibodies have been developed to study the role of chemokine receptors in healthy states and diseased states. These drug-like candidates are in turn exploited as radiolabeled probes for the imaging of chemokine receptors using noninvasive in vivo imaging, such as positron emission tomography (PET). Recent advances in the development of radiotracers for various chemokine receptors, particularly of CXCR4, CCR2, and CCR5, shed new light on chemokine-related cancer and cardiovascular research and the subsequent drug development. Here, we present the recent progress in PET radiotracer development for imaging of various chemokine receptors.

CXCL13 Signaling in the Tumor Microenvironment

Chemokines have emerged as important players in tumorigenic process. An extensive body of literature generated over the last two or three decades strongly implicate abnormally activated or functionally disrupted chemokine signaling in liaising most-if not all-hallmark processes of cancer. It is well-known that chemokine signaling networks within the tumor microenvironment are highly versatile and context-dependent: exert both pro-tumoral and antitumoral activities. The C-X-C motif chemokine ligand 13 (CXCL13), and its cognate receptor CXCR5, represents an emerging example of chemokine signaling axes, which express the ability to modulate tumor growth and progression in either way. Collateral evidence indicate that CXCL13-CXCR5 axis may directly modulate tumor growth by inducing proliferation of cancer cells, as well as promoting invasive phenotypes and preventing their apoptosis. In addition, CXCL13-CXCR5 axis may also indirectly modulate tumor growth by regulating noncancerous cells, particularly the immune cells, within the tumor microenvironment. Here, we review the role of CXCL13, together with CXCR5, in the human tumor microenvironment. We first elaborate their patterns of expression, regulation, and biological functions in normal physiology. We then consider how their aberrant activity, as a result of differential overexpression or co-expression, may directly or indirectly modulate the growth of tumors through effects on both cancerous and noncancerous cells.

EGR1 and RXRA transcription factors link TGF-β pathway and CCL2 expression in triple negative breast cancer cells

Transforming growth factor beta (TGF-β) is the main cytokine responsible for the induction of the epithelial-mesenchymal transition of breast cancer cells, which is a hallmark of tumor transformation to the metastatic phenotype. Recently, research demonstrated that the chemokine CCL2 gene expression level directly correlates with the TGF-β activity in breast cancer patients. CCL2 attracts tumor-associated macrophages and is, therefore, considered as an important inductor of breast cancer progression; however, the precise mechanisms underlying its regulation by TGF-β are unknown. Here, we studied the behavior of the CCL2 gene in MDA-MB-231 and HCC1937 breast cancer cells representing mesenchymal-like phenotype activated by TGF-β. Using bioinformatics, deletion screening and point mutagenesis, we identified binding sites in the CCL2 promoter and candidate transcription factors responsible for its regulation by TGF-β. Among these factors, only the knock-down of EGR1 and RXRA made CCL2 promoter activity independent of TGF-β. These factors also demonstrated binding to the CCL2 promoter in a TGF-β-dependent manner in a chromatin immunoprecipitation assay, and point mutations in the EGR1 and RXRA binding sites totally abolished the effect of TGF-β. Our results highlight the key role of EGR1 and RXRA transcription factors in the regulation of CCL2 gene in response to TGF-β pathway.

Role of p53-miRNAs circuitry in immune surveillance and cancer development: A potential avenue for therapeutic intervention

The genome's guardian, p53, is a master regulatory transcription factor that occupies sequence-specific response elements in many genes and modulates their expression. The target genes transcribe both coding RNA and non-coding RNA involved in regulating several biological processes such as cell division, differentiation, and cell death. Besides, p53 also regulates tumor immunology via regulating the molecules related to the immune response either directly or via regulating other molecules, including microRNAs (miRNAs). At the post-transcriptional level, the regulations of genes by miRNAs have been an emerging mechanism. Interestingly, p53 and various miRNAs cross-talk at different regulation levels. The cross-talk between p53 and miRNAs creates loops, turns, and networks that can influence cell metabolism, cell fate, cellular homeostasis, and tumor formation. Further, p53-miRNAs circuit has also been insinuated in the regulation of immune surveillance machinery. There are several examples of p53-miRNAs circuitry where p53 regulates immunomodulatory miRNA expression, such as miR-34a and miR-17-92. Similarly, a reverse process occurs in which miRNAs such as miR-125b and miR-let-7 regulate the expression of p53. Thus, the p53-miRNAs circuitry connects the immunomodulatory pathways and may shift the pro-inflammatory balance towards the pro-tumorigenic condition. In this review, we discuss the influence of p53-miRNAs circuitry in modulating the immune response in cancer development. We assume that thorough studies on the p53-miRNAs circuitry in various cancers may prove useful in developing effective new cancer therapeutics for successfully combating this disease.

Deficiency of C-X-C chemokine receptor type 5 (CXCR5) gene causes dysfunction of retinal pigment epithelium cells

Homeostasis of the retinal pigment epithelium (RPE) is essential for the health and proper function of the retina. Regulation of RPE homeostasis is, however, largely unexplored, yet dysfunction of this process may lead to retinal degenerative diseases, including age-related macular degeneration (AMD). Here, we report that chemokine receptor CXCR5 regulates RPE homeostasis through PI3K/AKT signaling and by suppression of FOXO1 activation. We used primary RPE cells isolated from CXCR5-deficient mice and wild type controls, as well as ex vivo RPE-choroidal-scleral complexes (RCSC) to investigate the regulation of homeostasis. CXCR5 expression in mouse RPE cells was diminished by treatment with hydrogen peroxide. Lack of CXCR5 expression leads to an abnormal cellular shape, pigmentation, decreased expression of the RPE differentiation marker RPE65, an increase in the undifferentiated progenitor marker MITF, and compromised RPE barrier function, as well as compromised cell-to-cell interaction. An increase in epithelial-mesenchymal transition (EMT) markers (αSMA, N-cadherin, and vimentin) was noted in CXCR5-deficient RPE cells both in vitro and in age-progression specimens of CXCR5-/- mice (6, 12, 24-months old). Deregulated autophagy in CXCR5-deficient RPE cells was observed by decreased LC3B-II, increased p62, abnormal autophagosomes, and impaired lysosome enzymatic activity as shown by GFP-LC3-RFP reporter plasmid. Mechanistically, deficiency in CXCR5 resulted in the downregulation of PI3K and AKT signaling, but upregulation and nuclear localization of FOXO1. Additionally, inhibition of PI3K in RPE cells resulted in an increased expression of FOXO1. Inhibition of FOXO1, however, reverts the degradation of ZO-1 caused by CXCR5 deficiency. Collectively, these findings suggest that CXCR5 maintains PI3K/AKT signaling, which controls FOXO1 activation, thereby regulating the expression of genes involved in RPE EMT and autophagy deregulation.

Transcriptome-Wide Analysis of CXCR5 Deficient Retinal Pigment Epithelial (RPE) Cells Reveals Molecular Signatures of RPE Homeostasis

Age-related macular degeneration (AMD) is the most common cause of irreversible blindness in the elderly population. In our previous studies, we found that deficiency of CXCR5 causes AMD-like pathological phenotypes in mice, characterized by abnormalities and dysfunction of the retinal pigment epithelium (RPE) cells. The abnormalities included abnormal cellular shape and impaired barrier function. In the present study, primary RPE cells were derived separately from CXCR5 knockout (KO) mice and from C57BL6 wild type (WT). The isolated primary cells were cultured for several days, and then total RNA was isolated and used for library preparation, sequencing, and the resultant raw data analyzed. Relative to the WT, a total of 1392 differentially expressed genes (DEG) were identified. Gene ontology analysis showed various biological processes, cellular components, and molecular functions were enriched. Pathway enrichment analysis revealed several pathways, including the PI3K-Akt signaling, mTOR signaling, FoxO, focal adhesion, endocytosis, ubiquitin-mediated proteolysis, TNFα-NF-kB Signaling, adipogenesis genes, p53 signaling, Ras, autophagy, epithelial–mesenchymal transition (EMT), and mitochondrial pathway. This study explores molecular signatures associated with deficiency of CXCR5 in RPE cells. Many of these signatures are important for homeostasis of this tissue. The identified pathways and genes require further evaluation to better understand the pathophysiology of AMD.

Matrine reduces the secretion of exosomal circSLC7A6 from cancer-associated fibroblast to inhibit tumorigenesis of colorectal cancer by regulating CXCR5

Tumor microenvironment (e.g., stromal cells) has been suggested to be implicated in colorectal cancer (CRC) progression. Of which, cancer-associated fibroblasts (CAFs) are believed as one of the key stromal cells in tumors. Traditionally, matrine was used to treat cancers, including CRC. Unfortunately, little is known about whether matrine inhibited CRC progression via CAFs. In this research, we analyzed cell proliferation, invasion and apoptosis by cell colony formation assay, transwell assay and Annexin V staining, respectively. circSLC7A6 and CXCR5 expression levels were examined by RT-qPCR. Exosomes were analyzed by NanoSight Tracking Analysis and exosome markers were probed by westernblot. In the results, we found that matrine significantly led to inhibited cell proliferation and invasion, and increased apoptosis. Moreover, matrine blocked circSLC7A6 exosome secretion from CAFs. circSLC7A6 acted as promoter for CRC cell proliferation and invasion, whereas as inhibitor for apoptosis. Clinically, circSLC7A6 was upregulated in CRC tumor tissues compared to adjacent normal tissues. In addition, circSLC7A6 was associated with higher overall survival. Eventually, we confirmed that chemokine receptor CXCR5 was a crucial effector for circSLC7A6-modulated tumorigenesis. Here, our data suggest matrine inhibits CRC tumorigenesis through blocking exosomal circSLC7A6 release from CAFs. This finding will provide strong evidence for treating CRC using matrine.

Dimethyl fumarate promotes B cell-mediated anti-inflammatory cytokine profile in B and T cells, and inhibits immune cell migration in patients with MS

Dimethyl Fumarate (DMF), known for its mechanism of action targeting Nrf2 and related redox homeostasis, is an approved immunotherapy for patients with Multiple Sclerosis (PwMS) in the relapsing form. We assessed how DMF modulates immune cell functions, namely the cytokine profile of co-cultured B and T cells, and the chemokine-mediated migration of immune cells. Following DMF therapy, LTα⁺, TNFα⁺ and IFNγ⁺ B cells were reduced while TGFβ and IL10 expression elevated. B cells from DMF-treated patients increased TGFβ and LTα expression on T cells, while DMF directly reduced TNFα⁺ and IFNγ⁺ T cells. CXCL12/CXCL13-mediated migration of B cells, Monocytes, CD4 and CD8 T cells was reduced, with altered CXCR5 and CXCR4 expression. Induction of regulatory B and T cells and reduced migration of immune cells may be part of the beneficial mechanism of DMF in PwMS.

p53, cancer and the immune response

The importance of cancer-cell-autonomous functions of the tumour suppressor p53 (encoded by TP53) has been established in many studies, but it is now clear that the p53 status of the cancer cell also has a profound impact on the immune response. Loss or mutation of p53 in cancers can affect the recruitment and activity of myeloid and T cells, allowing immune evasion and promoting cancer progression. p53 can also function in immune cells, resulting in various outcomes that can impede or support tumour development. Understanding the role of p53 in tumour and immune cells will help in the development of therapeutic approaches that can harness the differential p53 status of cancers compared with most normal tissue.

CXCR4 and CXCR3 are two distinct prognostic biomarkers in breast cancer: Database mining for CXCR family members

CXC chemokine receptors (CXCRs) and chemokines are involved in tissue development and homeostasis, including in cancer development and progression. To date, seven CXCRs have been identified. However, the expression of CXCRs and their influence on the occurrence and development of breast cancer (BC) requires further investigation. In the present study, mRNA expression levels of the seven CXCRs were compared between normal tissues and several cancer types using the Oncomine database. Highly expressed CXCRs were selected and the expression levels of these CXCRs were examined in different subtypes of BC using the Gene Expression-Based Outcome for Breast Cancer database. Finally, the prognostic value of these CXCRs was examined using Kaplan-Meier plotter. It was found that, compared with normal controls, transcripts of CXCR4 and CXCR3 were significantly overexpressed in BC samples compared with other CXCRs. Survival analysis showed that high expression of CXCR4 promoted the recurrence of BC but had no impact on overall survival (OS), while a high level of CXCR3 transcript expression was significantly associated with increased survival in patients with BC. With regards to different subtypes of BC, the present study revealed that high CXCR4 transcript expression was significantly associated with both longer relapse-free survival and OS only in basal-like BC. Furthermore, CXCR4 promoted chemosensitivity in patients with basal-like BC and induced resistance against endocrine therapy for patients with luminal A BC. Thus, CXCR4 and CXCR3 are two distinct prognostic biomarkers and further studies are required.

Autoimmune-Mediated Retinopathy in CXCR5-Deficient Mice as the Result of Age-Related Macular Degeneration Associated Proteins Accumulation

Previous research has shown that CXCR5^−/− mice develop retinal degeneration (RD) with age, a characteristic related to age macular degeneration (AMD). RD in these mice is not well-understood, and in this study, we sought to characterize further the RD phenotype and to gain mechanistic insights into the function of CXCR5 in the retina. CXCR5^−/− and WT control mice were used. Fundus images demonstrated a significant (p < 0.001) increase of hypo-pigmented spots in the retina of aged CXCR5^−/− mice compared with WT control mice. PAS staining indicated localization of deposits in the sub-retinal pigment epithelia (RPE) layer. AMD-associated proteins Cryab, amyloid beta, and C3d were detected within the RPE/sub-RPE tissues by immunofluorescence (IF). In addition, western blot analysis of COX-2, Arg1, and VEGF-a revealed an increase in the signaling of these molecules within the RPE/choroid complex. Transmission electron microscopy (TEM) indicated a drusen-like structure of sub-RPE deposits with an accumulation of vacuolated cellular debris. Loss of photoreceptors was detected by peanut lectin staining and was corroborated by a reduction in MAP2 signaling. Loss of blood-retinal barrier integrity was demonstrated by a reduction of ZO-1 expression. Inflammatory cells were detected in the sub-RPE space, with an increase in IBA-1 positive microglia cells on the surface of the RPE. Mass spectrometry analysis of CXCR5^−/− mouse RPE/choroid proteins extracts, separated by SDS-page and incubated with autologous serum, identified autoantibodies against AMD-associated proteins: Cryaa, Cryab, and Anxa2. In vitro evaluations in BV-2 cell culture indicated a significant increase in production of Arg-1 (p < 0.001) and COX-2 (p < 0.01) in the presence of anti-CXCR5 antibody when compared with Igg-treated control BV-2 cells stimulated with IL-4 and TNFα/IFNγ, respectively. Anti-CXCR5 antibody treatment without stimulating agents did not affect Arg-1 and COX-2 expression; this suggests that CXCR5 may have a regulatory role in microglia cells activation. These results indicate that with age, CXCR5^−/− mice develop RD characterized by microglia dysfunction, increased production of CXCL13 in the RPE progressive photoreceptor, neuronal loss, and sub-RPE deposition of cellular debris, resulting in the production of immunogenic proteins and autoimmune-mediated RD.

CXCL13 and Its Receptor CXCR5 in Cancer: Inflammation, Immune Response, and Beyond

It is well-established that the chemokine C-X-C motif ligand 13 (CXCL13) and its receptor, the G-protein coupled receptor (GPCR) CXCR5, play fundamental roles in inflammatory, infectious and immune responses. Originally identified as a B-cell chemoattractant, CXCL13 exerts important functions in lymphoid neogenesis, and has been widely implicated in the pathogenesis of a number of autoimmune diseases and inflammatory conditions, as well as in lymphoproliferative disorders. Current evidence also indicates that the CXCL13:CXCR5 axis orchestrates cell-cell interactions that regulate lymphocyte infiltration within the tumor microenvironment, thereby determining responsiveness to cytotoxic and immune-targeted therapies. In this review, we provide a comprehensive perspective of the involvement of CXCL13 and its receptor in cancer progression. Studies in recent years postulated novel roles for this chemokine in controlling the cancer cell phenotype, and suggest important functions in the growth and metastatic dissemination of solid tumors. Carcinogens have been found to induce CXCL13 production, and production of this chemokine within the tumor milieu has been shown to impact the proliferation, migration, and invasive properties of cancer cells. Thus, the complex networks of cellular interactions involving tumoral CXCL13 and CXCR5 integrate to promote cancer cell autonomous and non-autonomous responses, highlighting the relevance of autocrine and paracrine interactions in dictating the cancer phenotype. Dissecting the molecular and signaling events regulated by CXCL13 and how this chemokine dynamically controls the interaction between the cancer cell and the tumor microenvironment is key to identify novel effectors and therapeutic targets for cancer treatment.

CXCL13/CXCR5 signaling axis in cancer

The tumor microenvironment comprises stromal and tumor cells which interact with each other through complex cross-talks that are mediated by a variety of growth factors, cytokines, and chemokines. The chemokine ligand 13 (CXCL13) and its chemokine receptor 5 (CXCR5) are among the key chemotactic factors which play crucial roles in deriving cancer cell biology. CXCL13/CXCR5 signaling axis makes pivotal contributions to the development and progression of several human cancers. In this review, we discuss how CXCL13/CXCR5 signaling modulates cancer cell ability to grow, proliferate, invade, and metastasize. Furthermore, we also discuss the preliminary evidence on context-dependent functioning of this axis within the tumor-immune microenvironment, thus, highlighting its potential dichotomy with respect to anticancer immunity and cancer immune-evasion mechanisms. At the end, we briefly shed light on the therapeutic potential or implications of targeting CXCL13/CXCR5 axis within the tumor microenvironment.

RelA driven co-expression of CXCL13 and CXCR5 is governed by a multifaceted transcriptional program regulating breast cancer progression

Lethal metastasis of primary breast tumors to lymph nodes has been found to be associated with the co-expression of chemokine CXCL13 and its receptor CXCR5. To date, however, the precise molecular events regulating the co-expression of CXCL13 and CXCR5 in the context of breast cancer progression have not been identified. Therefore, to extend our understanding of the drivers of breast cancer metastasis, we undertook a line of investigation in this study in which we demonstrate that the transcriptional regulation of CXCL13 is mediated by the reciprocal activity of RelA and Nrf2, while CXCR5 is transcriptionally silenced by CpG island methylation within its promoter. Critically, we show that intra-tumoral CXCL13 and CXCR5 mRNA expression is positively correlated with intra-tumoral RelA expression within the primary tumor of breast cancer (BCa) patients (n = 98). We demonstrate a role for Nrf2 in the negative transcriptional regulation of cxcl13. Furthermore, using a luciferase assay and deletion analysis of the cxcl13 gene promoter, we demonstrate that RelA and Nrf2 directly act upon the cxcl13 promoter to regulate transcription. Chromatin immunoprecipitation PCR, supported by in silico docking analyses, confirmed that RelA and Nrf2 both occupy multiple positions within the cxcl13 promoter. Collectively, in RelA high conditions, low Nrf2 and lack of cxcr5 promoter DNA-methylation govern CXCL13-CXCR5 co-expression within breast tumors, and thus drive disease progression and metastasis.

Glucocorticoid Receptor Binding Inhibits an Intronic IL33 Enhancer and is Disrupted by rs4742170 (T) Allele Associated with Specific Wheezing Phenotype in Early Childhood

Interleukin 33 (IL-33) is a cytokine constitutively expressed by various cells of barrier tissues that contribute to the development of inflammatory immune responses. According to its function as an alarmin secreted by lung and airway epithelium, IL-33 plays a significant role in pathogenesis of allergic disorders. IL-33 is strongly involved in the pathogenesis of asthma, anaphylaxis, allergy and dermatitis, and genetic variations in IL33 locus are associated with increased susceptibility to asthma. Genome-wide association studies have identified risk "T" allele of the single-nucleotide polymorphism rs4742170 located in putative IL33 enhancer area as susceptible variant for development of specific wheezing phenotype in early childhood. Here, we demonstrate that risk "T" rs4742170 allele disrupts binding of glucocorticoid receptor (GR) transcription factor to IL33 putative enhancer. The IL33 promoter/enhancer constructs containing either 4742170 (T) allele or point mutations in the GR-binding site, were significantly more active and did not respond to cortisol in a pulmonary epithelial cell line. At the same time, the constructs containing rs4742170 (C) allele with a functional GR-binding site were less active and further inhibitable by cortisol. The latter effect was GR-dependent as it was completely abolished by GR-specific siRNA. This mechanism may explain the negative effect of the rs4742170 (T) risk allele on the development of wheezing phenotype that strongly correlates with allergic sensitization in childhood.

Role of curcumin in regulating p53 in breast cancer: an overview of the mechanism of action

p53 is a tumor suppressor gene involved in various cellular mechanisms including DNA repair, apoptosis, and cell cycle arrest. More than 50% of human cancers have a mutated nonfunctional p53. Breast cancer (BC) is one of the main causes of cancer-related deaths among females. p53 mutations in BC are associated with low survival rates and more resistance to the conventional therapies. Thus, targeting p53 activity was suggested as an important strategy in cancer therapy. During the past decades, cancer research was focused on the development of monotargeted anticancer therapies. However, the development of drug resistance by modulation of genes, proteins, and pathways was the main hindrance to the success of such therapies. Curcumin is a natural product, extracted from the roots of Curcuma longa, and possesses various biological effects including anticancer activity. Previous studies proved the ability of curcumin to modulate several signaling pathways and biomolecules in cancer. Safety and cost-effectiveness are additional inevitable advantages of curcumin. This review summarizes the effects of curcumin as a regulator of p53 in BC and the key molecular mechanisms of this regulation.

Hypoacylated LPS from Foodborne Pathogen Campylobacter jejuni Induces Moderate TLR4-Mediated Inflammatory Response in Murine Macrophages

Toll-like receptor 4 (TLR4) initiates immune response against Gram-negative bacteria upon specific recognition of lipid A moiety of lipopolysaccharide (LPS), the major component of their cell wall. Some natural differences between LPS variants in their ability to interact with TLR4 may lead to either insufficient activation that may not prevent bacterial growth, or excessive activation which may lead to septic shock. In this study we evaluated the biological activity of LPS isolated from pathogenic strain of Campylobacter jejuni, the most widespread bacterial cause of foodborne diarrhea in humans. With the help of hydrophobic chromatography and MALDI-TOF mass spectrometry we showed that LPS from a C. jejuni strain O2A consists of both hexaacyl and tetraacyl forms. Since such hypoacylation can result in a reduced immune response in humans, we assessed the activity of LPS from C. jejuni in mouse macrophages by measuring its capacity to activate TLR4-mediated proinflammatory cytokine and chemokine production, as well as NFκB-dependent reporter gene transcription. Our data support the hypothesis that LPS acylation correlates with its bioactivity.

Network-based co-expression analysis for exploring the potential diagnostic biomarkers of metastatic melanoma

Metastatic melanoma is an aggressive skin cancer and is one of the global malignancies with high mortality and morbidity. It is essential to identify and verify diagnostic biomarkers of early metastatic melanoma. Previous studies have systematically assessed protein biomarkers and mRNA-based expression characteristics. However, molecular markers for the early diagnosis of metastatic melanoma have not been identified. To explore potential regulatory targets, we have analyzed the gene microarray expression profiles of malignant melanoma samples by co-expression analysis based on the network approach. The differentially expressed genes (DEGs) were screened by the EdgeR package of R software. A weighted gene co-expression network analysis (WGCNA) was used for the identification of DEGs in the special gene modules and hub genes. Subsequently, a protein-protein interaction network was constructed to extract hub genes associated with gene modules. Finally, twenty-four important hub genes (RASGRP2, IKZF1, CXCR5, LTB, BLK, LINGO3, CCR6, P2RY10, RHOH, JUP, KRT14, PLA2G3, SPRR1A, KRT78, SFN, CLDN4, IL1RN, PKP3, CBLC, KRT16, TMEM79, KLK8, LYPD3 and LYPD5) were treated as valuable factors involved in the immune response and tumor cell development in tumorigenesis. In addition, a transcriptional regulatory network was constructed for these specific modules or hub genes, and a few core transcriptional regulators were found to be mostly associated with our hub genes, including GATA1, STAT1, SP1, and PSG1. In summary, our findings enhance our understanding of the biological process of malignant melanoma metastasis, enabling us to identify specific genes to use for diagnostic and prognostic markers and possibly for targeted therapy.

p53 Deletion promotes myeloma cells invasion by upregulating miR19a/CXCR5

P53 deletion has been identified as one of the few factors that defined high risk and poor prognosis in MM. It has been reported p53 deletion is associated with resistance to chemotherapy and organ infiltrations of MM. However, p53 deletion in the migration and dissemination of MM cells has not been totally elucidated. In this research, first, we investigated whether p53 is associated with migration of MM cells. We found that p53 regulates the migration of NCI-H929 cells with wild-type p53 but not U266 cells with mutated-type p53. Next, we investigated the related mechanism by which p53 regulates the migration. We found that down-regulation of p53 reduced adhesion of NCI-H929 cells to the BM stroma via decreased expression of E-cadherin and increased EMT-regulating proteins. Further study have identified the miR-19a/CXCR5 pathway as a candidate p53-induced migration mechanism. In conclusion, we have demonstrated for the first time the critical value of p53 deletion in MM cell migration and dissemination, as well as the acquisition of an EMT-like phenotype. Our research provides new insights into the function of p53 in migration of MM and suggests p53/miRNA19a/CXCR5 may provide potentially therapeutic targets for the treatment of myeloma with p53 deletion.

The prognostic implications of growth-related gene product β in laryngeal squamous cell carcinoma

Growth-related gene product β (GROβ) is an angiogenic chemokine that belongs to the CXC chemokine family, and a number of studies have suggested that GROβ is associated with tumor development and progression. However, a number of studies have investigated the association between GROβ expression and the clinical attributes of laryngeal squamous cell carcinoma (LSCC). In the present study, one-step quantitative polymerase chain reaction and immunohistochemistry analysis were used to detect GROβ expression and evaluate the association between its expression and the clinicopathological characteristics of LSCC. The results demonstrated that the GROβ mRNA and protein expression levels were significantly increased in LSCC compared with the corresponding non-cancerous tissues. GROβ protein expression in LSCC was associated with tumor-node-metastasis stage, lymph node metastasis and histopathological grade. The Kaplan-Meier method and Cox multi-factor analysis indicated that high GROβ expression, lymph node metastasis and histopathological grade were significantly associated with poor survival of patients with LSCC. These data indicated that GROβ may be a novel prognostic biomarker of LSCC.

CITED2 in breast carcinoma as a potent prognostic predictor associated with proliferation, migration and chemoresistance

CITED2 (Cbp/p300‐interacting transactivator, with Glu/Asp‐rich carboxy‐terminal domain, 2) is a member of the CITED family and is involved in various cellular functions during development and differentiation. Mounting evidence suggests the importance of CITED in the progression of human malignancies, but the significance of CITED2 protein has not yet been examined in breast carcinoma. Therefore, in the present study, we examined the clinical significance and the biological functions of CITED2 in breast carcinoma by immunohistochemistry and in vitro study. CITED2 immunoreactivity was detected in breast carcinoma tissues, and it was significantly higher compared to those in morphologically normal mammary glands. CITED2 immunoreactivity was significantly associated with stage, pathological T factor, lymph node metastasis, histological grade, HER2 and Ki‐67, and inversely correlated with estrogen receptor. Moreover, the immunohistochemical CITED2 status was significantly associated with increased incidence of recurrence and breast cancer‐specific death of the breast cancer patients, and multivariate analyses demonstrated CITED2 status as an independent worse prognostic factor for disease‐free and breast cancer‐specific survival. Subsequent in vitro experiments showed that CITED2 expression significantly increased proliferation activity and migration property in MCF‐7and S KBR‐3 breast carcinoma cells. Moreover, CITED2 caused chemoresistance to epirubicin and 5‐fluorouracil, but not paclitaxel, in these cells, and it inhibited p53 accumulation after 5‐fluorouracil treatment in MCF‐7 cells. These results suggest that CITED2 plays important roles in the progression and chemoresistance of breast carcinoma and that CITED2 status is a potent prognostic factor in breast cancer patients.

Chemokine Receptor Signaling and the Hallmarks of Cancer

The chemokines are a family of chemotactic cytokines that mediate their activity by acting on seven-transmembrane-spanning G protein-coupled receptors. Both the ability of the chemokines and their receptors to form homo- and heterodimers and the promiscuity of the chemokine-chemokine receptor interaction endow this protein family with enormous signaling plasticity and complexity that are not fully understood at present. Chemokines were initially identified as essential regulators of homeostatic and inflammatory trafficking of innate and adaptive leucocytes from lymphoid organs to tissues. Chemokines also mediate the host response to cancer. Nevertheless, chemokine function in this response is not limited to regulating leucocyte infiltration into the tumor microenvironment. It is now known that chemokines and their receptors influence most-if not all-hallmark processes of cancer; they act on both neoplastic and untransformed cells in the tumor microenvironment, including fibroblasts, endothelial cells (blood and lymphatic), bone marrow-derived stem cells, and, obviously, infiltrating leucocytes. This review begins with an overview of chemokine and chemokine receptor structure, to better define how chemokines affect the proliferation, survival, stemness, and metastatic potential of neoplastic cells. We also examine the main mechanisms by which chemokines regulate tumor angiogenesis and immune cell infiltration, emphasizing the pro- and antitumorigenic activity of this protein superfamily in these interrelated processes.

Transcriptomic Analysis Implicates the p53 Signaling Pathway in the Establishment of HIV-1 Latency in Central Memory CD4 T Cells in an In Vitro Model

The search for an HIV-1 cure has been greatly hindered by the presence of a viral reservoir that persists despite antiretroviral therapy (ART). Studies of HIV-1 latency in vivo are also complicated by the low proportion of latently infected cells in HIV-1 infected individuals. A number of models of HIV-1 latency have been developed to examine the signaling pathways and viral determinants of latency and reactivation. A primary cell model of HIV-1 latency, which incorporates the generation of primary central memory CD4 T cells (TCM), full-length virus infection (HIVNL4-3) and ART to suppress virus replication, was used to investigate the establishment of HIV latency using RNA-Seq. Initially, an investigation of host and viral gene expression in the resting and activated states of this model indicated that the resting condition was reflective of a latent state. Then, a comparison of the host transcriptome between the uninfected and latently infected conditions of this model identified 826 differentially expressed genes, many of which were related to p53 signaling. Inhibition of the transcriptional activity of p53 by pifithrin-α during HIV-1 infection reduced the ability of HIV-1 to be reactivated from its latent state by an unknown mechanism. In conclusion, this model may be used to screen latency reversing agents utilized in shock and kill approaches to cure HIV, to search for cellular markers of latency, and to understand the mechanisms by which HIV-1 establishes latency.

The A Allele of the Single-Nucleotide Polymorphism rs630923 Creates a Binding Site for MEF2C Resulting in Reduced CXCR5 Promoter Activity in B-Cell Lymphoblastic Cell Lines

Chemokine receptor CXCR5 is highly expressed in B-cells and under normal conditions is involved in their migration to specific areas of secondary lymphoid organs. B-cells are known to play an important role in various autoimmune diseases including multiple sclerosis (MS) where areas of demyelinating lesions attract B-cells by overexpressing CXCL13, the CXCR5 ligand. In this study, we aimed to determine the functional significance of single-nucleotide polymorphism rs630923 (A/C), which is located in cxcr5 gene promoter, and its common allele is associated with increased risk of MS. Using bioinformatics and pull-down assay in B-lymphoblastic cell lines, we showed that protective minor rs630923 "A" allele created functional binding site for MEF2C transcription factor. Elevated MEF2C expression in B-cells correlated with reduced activity of cxcr5 promoter containing rs630923 "A" allele. This effect that was fully neutralized by MEF2C-directed siRNA may mechanistically explain the protective role of the rs630923 minor allele in MS. Using site-directed mutagenesis of the cxcr5 gene promoter, we were unable to find any experimental evidence for the previously proposed role of NFκB transcription factors in rs630923-mediated CXCR5 promoter regulation. Thus, our results identify MEF2C as a possible mediator of protective function of the rs630923 "A" allele in MS.

mRNA-Producing Pseudo-nucleus System

A pseudo-eukaryotic nucleus (PEN) system consisting of a gene-containing DNA hydrogel encapsulated in a liposome is fabricated. Owing to the structural characteristics of gene-containing DNA hydrogel, mRNA transcription efficiency is promoted 2.57-fold. Through the use of PEN as a platform for mRNA delivery to the cytosol, prolonged protein translation is achieved.