CXC Chemokine Ligand 13 and CC Chemokine Ligand 19 Cooperatively Render Resistance to Apoptosis in B Cell Lineage Acute and Chronic Lymphocytic Leukemia CD23+CD5+B Cells

Molecular Mechanisms and Therapeutic Prospects of Immunotherapy and Targeted Therapy in Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a very rare extranodal non-Hodgkin's lymphoma confined to the brain, eyes, spinal cord, and cerebrospinal fluid (CSF). This disease is highly aggressive. For decades, high-dose methotrexate-based induction regimens have been the standard treatment for PCNSL and have significantly improved patient overall survival (OS). However, some patients still experience disease recurrence or develop drug resistance. With a deeper understanding of the pathophysiology of PCNSL, various therapies, including CD20 monoclonal antibodies, Bruton's tyrosine kinase (BTK) inhibitors, immunomodulatory drugs, immune checkpoint inhibitors, phosphoinositide 3-kinase (PI3 K)/mammalian target of rapamycin(mTOR) inhibitors, and chimeric antigen receptor (CAR) -T cells are increasingly being applied and have demonstrated considerable efficacy. These therapies have paved the way for novel treatment strategies in PCNSL, representing a highly promising field. Investigating the mechanisms, specific targets, and signaling pathways, as well as interactions with the tumor microenvironment (TME), can provide a solid foundation for further exploration and potentially enhance the optimization of treatment approaches for PCNSL. This review seeks to explore the characteristics of the TME in PCNSL, elucidate the molecular mechanisms of various immunotherapies and targeted therapies, examine their interactions with the TME, and summarize the advancements in the research of PCNSL immunotherapy and targeted therapy.

CXCL13 Positive Cells Localization Predict Response to Anti-PD-1/PD-L1 in Pulmonary Non-Small Cell Carcinoma

Background: Immune checkpoint inhibitors (ICIs) have revolutionized non-small cell lung cancers (NSCLCs) treatment, but only 20-30% of patients benefit from these treatments. Currently, PD-L1 expression in tumor cells is the only clinically approved predictor of ICI response in lung cancer, but concerns arise due to its low negative and positive predictive value. Recent studies suggest that CXCL13+ T cells in the tumor microenvironment (TME) may be a good predictor of response. We aimed to assess if CXCL13+ cell localization within the TME can predict ICI response in advanced NSCLC patients. Methods: This retrospective study included 65 advanced NSCLC patients treated with Nivolumab/Pembrolizumab at IUCPQ or CHUM and for whom a pretreatment surgical specimen was available. Good responders were defined as having a complete radiologic response at 1 year, and bad responders were defined as showing cancer progression at 1 year. IHC staining for CXCL13 was carried out on a representative slide from a resection specimen, and CXCL13+ cell density was evaluated in tumor (T), invasive margin (IM), non-tumor (NT), and tertiary lymphoid structure (TLS) compartments. Cox models were used to analyze progression-free survival (PFS) and overall survival (OS) probability, while the Mann-Whitney test was used to compare CXCL13+ cell density between responders and non-responders. Results: We showed that CXCL13+ cell density localization within the TME is associated with ICI efficacy. An increased density of CXCL13+ cells across all compartments was associated with a poorer prognostic (OS; HR = 1.22; 95%CI = 1.04-1.42; p = 0.01, PFS; HR = 1.16; p = 0.02), or a better prognostic when colocalized within TLSs (PFS; HR = 0.84, p = 0.03). Conclusion: Our results support the role of CXCL13+ cells in advanced NSCLC patients, with favorable prognosis when localized within TLSs and unfavorable prognosis when present elsewhere. The concomitant proximity of CXCL13+ and CD20+ cells within TLSs may favor antigen presentation to T cells, thus enhancing the effect of PD-1/PD-L1 axis inhibition. Further validation is warranted to confirm the potential relevance of this biomarker in a clinical setting.

Class I Myosins, molecular motors involved in cell migration and cancer

Class I Myosins are a subfamily of motor proteins with ATPase activity and a characteristic structure conserved in all myosins: A N-Terminal Motor Domain, a central Neck and a C terminal Tail domain. Humans have eight genes for these myosins. Class I Myosins have different functions: regulate membrane tension, participate in endocytosis, exocytosis, intracellular trafficking and cell migration. Cell migration is influenced by many cellular components including motor proteins, like myosins. Recently has been reported that changes in myosin expression have an impact on the migration of cancer cells, the formation of infiltrates and metastasis. We propose that class I myosins might be potential markers for future diagnostic, prognostic or even as therapeutic targets in leukemia and other cancers.Abbreviations: Myo1g: Myosin 1g; ALL: Acute Lymphoblastic Leukemia, TH1: Tail Homology 1; TH2: Tail Homology 2; TH3: Tail Homology 3.

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.

The Diagnostic Significance of CXCL13 in M2 Tumor Immune Microenvironment of Human Astrocytoma

Background: CXCL13 may act as a mediator of tumor-associated macrophage immunity during malignant progression. Objective: The present study clarifies the clinicopathological significances of CXCL13 and its corresponding trend with M2 macrophage in human astrocytoma. Methods: The predictive potential of CXCL13 was performed using 695 glioma samples derived from TCGA lower-grade glioma and glioblastoma (GBMLGG) dataset. CXCL13 and M2 biomarker CD163 were observed by immunohistochemistry in 112 astrocytoma tissues. Results: An in-depth analysis showed that CXCL13 expression was related to the poor prognosis of glioma patients (p = 0.0002) derive from TCGA analysis. High level of CXCL13 was detected in 43 (38.39%) astrocytoma and CXCL13/CD163 coexpression was expressed in 33 (29.46%) cases. The immunoreactivities of CXCL13 and CXCL13/CD163 were found in the malignant lesions, which were both significantly associated with grade, patient survival, and IDH1 mutation. Single CXCL13 and CXCL13/CD163 coexpression predicted poor overall survival in astrocytoma (p = 0.0039 and p = 0.0002, respectively). Multivariate Cox regression analyses manifested CXCL13/CD163 phenotype was a significant independent prognostic indicator of patient outcome in astrocytoma (CXCL13, p = 0.0642; CXCL13/CD163, p = 0.0368). Conclusion: CXCL13 overexpression is strongly linked to CD163+ M2 infiltration in malignant astrocytoma. CXCL13/CD163 coexpression would imply M2c-related aggressive characteristics existing in astrocytoma progression could also provide predictive trends of patient outcomes.

Gag-like proteins: Novel mediators of prenatal alcohol exposure in neural development

Background

We previously showed that ethanol did not kill fetal neural stem cells (NSCs), but that their numbers nevertheless are decreased due to aberrant maturation and loss of self‐renewal. To identify mechanisms that mediate this loss of NSCs, we focused on a family of Gag‐like proteins (GLPs), derived from retroviral gene remnants within mammalian genomes. GLPs are important for fetal development, though their role in brain development is virtually unexplored. Moreover, GLPs may be transferred between cells in extracellular vesicles (EVs) and thereby transfer environmental adaptations between cells. We hypothesized that GLPs may mediate some effects of ethanol in NSCs.

Methods

Sex‐segregated male and female fetal murine cortical NSCs, cultured ex vivo as nonadherent neurospheres, were exposed to a dose range of ethanol and to mitogen‐withdrawal‐induced differentiation. We used siRNAs to assess the effects of NSC‐expressed GLP knockdown on growth, survival, and maturation and in silico GLP knockout, in an in vivo single‐cell RNA‐sequencing dataset, to identify GLP‐mediated developmental pathways that were also ethanol‐sensitive.

Results

PEG10 isoform‐1, isoform‐2, and PNMA2 were identified as dominant GLP species in both NSCs and their EVs. Ethanol‐exposed NSCs exhibited significantly elevated PEG10 isoform‐2 and PNMA2 protein during differentiation. Both PEG10 and PNMA2 were mediated apoptosis resistance and additionally, PEG10 promoted neuronal and astrocyte lineage maturation. Neither GLP influenced metabolism nor cell cycle in NSCs. Virtual PEG10 and PNMA2 knockout identified gene transcription regulation and ubiquitin‐ligation processes as candidate mediators of GLP‐linked prenatal alcohol effects.

Conclusions

Collectively, GLPs present in NSCs and their EVs may confer apoptosis resistance within the NSC niche and contribute to the abnormal maturation induced by ethanol.

C-C Chemokine Receptor 7 in Cancer

C-C chemokine receptor 7 (CCR7) was one of the first two chemokine receptors that were found to be upregulated in breast cancers. Chemokine receptors promote chemotaxis of cells and tissue organization. Since under homeostatic conditions, CCR7 promotes migration of immune cells to lymph nodes, questions immediately arose regarding the ability of CCR7 to direct migration of cancer cells to lymph nodes. The literature since 2000 was examined to determine to what extent the expression of CCR7 in malignant tumors promoted migration to the lymph nodes. The data indicated that in different cancers, CCR7 plays distinct roles in directing cells to lymph nodes, the skin or to the central nervous system. In certain tumors, it may even serve a protective role. Future studies should focus on defining mechanisms that differentially regulate the unfavorable or beneficial role that CCR7 plays in cancer pathophysiology, to be able to improve outcomes in patients who harbor CCR7-positive cancers.

Does CCL19 act as a double-edged sword in cancer development?

Cancer is considered a life-threatening disease, and several factors are involved in its development. Chemokines are small proteins that physiologically exert pivotal roles in lymphoid and non-lymphoid tissues. The imbalance or dysregulation of chemokines has contributed to the development of several diseases, especially cancer. CCL19 is one of the homeostatic chemokines that is abundantly expressed in the thymus and lymph nodes. This chemokine, which primarily regulates immune cell trafficking, is involved in cancer development. Through the induction of anti-tumor immune responses and inhibition of angiogenesis, CCL19 exerts tumor-suppressive functions. In contrast, CCL19 also acts as a tumor-supportive factor by inducing inflammation, cell growth, and metastasis. Moreover, CCL19 dysregulation in several cancers, including colorectal, breast, pancreatic, and lung cancers, has been considered a tumor biomarker for diagnosis and prognosis. Using CCL19-based therapeutic approaches has also been proposed to overcome cancer development. This review will shed more light on the multifarious function of CCL19 in cancer and elucidate its application in diagnosis, prognosis, and even therapy. It is expected that the study of CCL19 in cancer might be promising to broaden our knowledge of cancer development and might introduce novel approaches in cancer management.

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.

CCR7 in Blood Cancers - Review of Its Pathophysiological Roles and the Potential as a Therapeutic Target

According to the classical paradigm, CCR7 is a homing chemokine receptor that grants normal lymphocytes access to secondary lymphoid tissues such as lymph nodes or spleen. As such, in most lymphoproliferative disorders, CCR7 expression correlates with nodal or spleen involvement. Nonetheless, recent evidence suggests that CCR7 is more than a facilitator of lymphatic spread of tumor cells. Here, we review published data to catalogue CCR7 expression across blood cancers and appraise which classical and novel roles are attributed to this receptor in the pathogenesis of specific hematologic neoplasms. We outline why novel therapeutic strategies targeting CCR7 might provide clinical benefits to patients with CCR7-positive hematopoietic tumors.

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.

Of Lymph Nodes and CLL Cells: Deciphering the Role of CCR7 in the Pathogenesis of CLL and Understanding Its Potential as Therapeutic Target

The lymph node (LN) is an essential tissue for achieving effective immune responses but it is also critical in the pathogenesis of chronic lymphocytic leukemia (CLL). Within the multitude of signaling pathways aberrantly regulated in CLL the homeostatic axis composed by the chemokine receptor CCR7 and its ligands is the main driver for directing immune cells to home into the LN. In this literature review, we address the roles of CCR7 in the pathophysiology of CLL, and how this chemokine receptor is of critical importance to develop more rational and effective therapies for this malignancy.

Diagnosis, prognosis and treatment of primary central nervous system lymphoma in the elderly population (Review)

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal non-Hodgkin lymphoma that is unique and different from systemic diffuse large B-cell lymphomas. The median age at diagnosis of PCNSL is 65 years and its incidence is rising rapidly in the elderly population. A total of ≥20% of all patients with PCNSL are ≥80 years old. Notably, age has been identified as an independent poor prognostic factor for PCNSL. Elderly patients have an inferior prognosis to that of younger patients and are more severely affected by iatrogenic toxicity; therefore, elderly patients represent a unique and vulnerable treatment subgroup. The present review summarized the available literature to provide an improved understanding of the epidemiology, clinical characteristics, diagnosis, prognosis and management of PCNSL in the elderly population. Notably, the incidence of PCNSL in immunocompetent elderly patients, predominantly in men, is increasing. For the diagnosis of CNSL, imaging-guided stereotactic biopsy is considered the gold standard. When stereotactic biopsy is not possible or conclusive, certain biomarkers have been described that can help establish a diagnosis. PCNSL has a very poor prognosis in the elderly, even though several prognostic scoring systems exist and several prognostic markers have been reported in patients with PCNSL. Furthermore, the treatment of elderly patients remains challenging; it is unlikely that a novel agent could be used as a curative monotherapy; however, a combination of novel agents with polychemotherapy or its combination with other novel drugs may have therapeutic potential.

Targeting cancer homing into the lymph node with a novel anti-CCR7 therapeutic antibody: the paradigm of CLL

Lymph node (LN) is a key tissue in the pathophysiology of mature blood cancers, especially for chronic lymphocytic leukemia (CLL). Within the multiple de-regulated pathways affecting CLL homeostasis, the CC-chemokine receptor 7 (CCR7) grants homing of CLL cells into the LN where protective environments foster tumor progression. To cover the lack of specific therapies targeting the CCR7-dependence of CLL to enter into the LN, and aiming to displace the disease from LN, we generated CAP-100, an antibody that specifically binds to hCCR7 and neutralizes its ligand-binding site and signaling. In various in vitro and in vivo preclinical models CAP-100 strongly inhibited CCR7-induced migration, extravasation, homing, and survival in CLL samples. Moreover, it triggered potent tumor cell killing, mediated by host immune mechanisms, and was effective in xenograft models of high-risk disease. Additionally, CAP-100 showed a favorable toxicity profile on relevant hematopoietic subsets. Our results validated CAP-100 as a novel therapeutic tool to prevent the access of CLL cells, and other neoplasia with nodal-dependence, into the LN niches, thus hitting a central hub in the pathogenesis of cancer. The first-in-human clinical trial (NCT04704323), which will evaluate this novel therapeutic approach in CLL patients, is pending.

Duality of B Cell-CXCL13 Axis in Tumor Immunology

Tumor immunity is a rapidly evolving area of research consisting of many possible permutations of immune cell tumor interactions that are dependent upon cell type, tumor type, and stage in tumor progression. At the same time, the majority of cancer immunotherapies have been focused on modulating the T cell-mediated antitumor immune response and have largely ignored the potential utility that B cells possess with respect to tumor immunity. Therefore, this motivated an exploration into the role that B cells and their accompanying chemokine, CXCL13, play in tumor immunity across multiple tumor types. Both B cells and CXCL13 possess dualistic impacts on tumor progression and tumor immunity which is furthered detail in this review. Specifically, various B cells subtypes are able to suppress or enhance several important immunological functions. Paradoxically, CXCL13 has been shown to drive several pro-growth and invasive signaling pathways across multiple tumor types, while also, correlating with improved survival and immune cell tumor localization in other tumor types. Potential tools for better elucidating the mechanisms by which B cells and CXCL13 impact the antitumor immune response are also discussed. In addition, multiples strategies are proposed for modulating the B cell-CXCL13 axis for cancer immunotherapies.

Molecular profiling of primary central nervous system lymphomas - predictive and prognostic value?

PURPOSE OF REVIEW

Primary central nervous system lymphoma (PCNSL) is a rare but aggressive variant of non-Hodgkin lymphoma. The diagnostic gold standard remains the pathologic review of tumor tissue mainly collected though biopsies. The majority of PCNSL are diffuse large B cell lymphoma (DLBCL). Biopsies are invasive procedures, and there have been efforts to develop minimally invasive diagnostic testing using serum and cerebral spinal fluid. This article reviews multiple markers that could potentially serve as future diagnostic tools and predictors of treatment response.

RECENT FINDINGS

Many studies have attempted to classify DLBCL into different subtypes for prognostic purposes using methods such as immunohistochemistry. PCNSL often falls under the activated B-cell-like subgroup, and further genomic sequencing has identified alterations in genes within the B-cell receptor signaling axis at increased frequencies. Two such genes, MYD88 and CD79B, implicate the involvement of the NF-kB (nuclear factor kappa-light-chain enhancer of activated B cells) pathway, and targeted agents to this pathway are currently being used in the treatment of relapsed/refractory PCNSL.

SUMMARY

Although recent genomic profiling of PCNSL has increased the understanding of drivers in this disease and has also led to the introduction of targeted inhibitors, these markers have not yet been used for diagnostic and/or prognostic purposes. Further studies will need to evaluate if they hold great diagnostic potential.

Functional Study of the Retrotransposon-Derived Human PEG10 Protease

Paternally expressed gene 10 (PEG10) is a human retrotransposon-derived imprinted gene. The mRNA of PEG10 encodes two protein isoforms: the Gag-like protein (RF1_PEG10) is coded by reading frame 1, while the Gag-Pol-like polyprotein (RF1/RF2_PEG10) is coded by reading frames 1 and 2. The proteins are translated by a typical retroviral frameshift mechanism. The protease (PR) domain of RF2_PEG10 contains an -Asp-Ser-Gly- sequence, which corresponds to the consensus -Asp-Ser/Thr-Gly- active-site motif of retroviral aspartic proteases. The function of the aspartic protease domain of RF2_PEG10 remains unclear. To elucidate the function of PEG10 protease (PR_PEG10), we designed a frameshift mutant (_fsRF1/RF2_PEG10) for comparison with the RF1/RF2_PEG10 form. To study the effects of PR_PEG10 on cellular proliferation and viability, mammalian HEK293T and HaCaT cells were transfected with plasmids coding for either RF1/RF2_PEG10, the frameshift mutant (_fsRF1/RF2_PEG10), or a PR active-site (D370A) mutant _fsRF1/RF2_PEG10. Our results indicate that _fsRF1/RF2_PEG10 overexpression results in increased cellular proliferation. Remarkably, transfection with _fsRF1/RF2_PEG10 had a detrimental effect on cell viability. We hypothesize that PR_PEG10 plays an important role in the function of this retroviral remnant, mediating the proliferation of cells and possibly implicating it in the inhibition of apoptosis.

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.

Suppression of lymphocyte apoptosis in spleen by CXCL13 after porcine circovirus type 2 infection and regulatory mechanism of CXCL13 expression in pigs

Porcine circovirus-associated disease (PCVAD) is one of the most serious infectious diseases in pigs worldwide. The primary causative agent of PCVAD is porcine circovirus type 2 (PCV2), which can cause lymphoid depletion and immunosuppression in pigs. Our previous study demonstrated that Laiwu (LW) pigs, a Chinese indigenous pig breed, have stronger resistance to PCV2 infection than Yorkshire × Landrace (YL) pigs. In this study, we found that the YL pigs showed more severe lymphocyte apoptosis and higher viral load in the spleen tissue than LW pigs. To illustrate the differential gene expression between healthy and infected spleens, transcriptome profiling of spleen tissues from PCV2-infected and control YL pigs was compared by RNA sequencing. A total of 90 differentially expressed genes (DEGs) was identified, including CD207, RSAD2, OAS1, OAS2, MX2, ADRB3, CXCL13, CCR1, and ADRA2C, which were significantly enriched in gene ontology (GO) terms related to the defense response to virus and cell-cell signaling, and another nine DEGs, KLF11, HGF, PTGES3, MAP3K11, XDH, CYCS, ACTC1, HSPH1, and RYR2, which were enriched in GO terms related to regulation of cell proliferation or apoptosis. Among these DEGs, the CXCL13 gene, which can suppress lymphocyte apoptosis during PCV2 infection, was significantly down-regulated in response to PCV2 infection in YL but not in LW pigs. By analysis of the regulatory elements in the promoter and 3'-untranslated region (3'-UTR) of porcine CXCL13, we found that the single nucleotide polymorphism (SNP) -1014 G (LW) > A (YL) and the Sus scrofa microRNA-296-5p (ssc-miR-296-5p) participated in regulating CXCL13 expression during the response to PCV2 infection.

Th2 cell differentiation from naive CD4+ T cells is enhanced by autocrine CC chemokines in atopic diseases

BACKGROUND

Chemokines are involved not only in regulating leucocyte recruitment, but also in other activities. However, functions other than cell recruitment remain poorly understood. We have already shown that the production of CC chemokine ligand (CCL)17 and CCL22 by antigen-stimulated naïve CD4⁺  T cells was higher in asthmatic patients than in healthy controls. However, the role of these chemokines in stimulated naïve CD4⁺ T cells remains unclear.

OBJECTIVE

To clarify the biological function of CCL17 and CCL22 on naïve CD4⁺ T, we examined effects of these two chemokines on naïve CD4⁺ T cells expressing CC chemokine receptor (CCR)4 (a receptor for CCL17 and CCL22) during differentiation of Th2 cells in asthmatic patients as allergic subjects.

METHODS

Naïve CD4⁺ T cells were prepared from healthy controls and patients with asthma. We analysed effect of CCL17 and CCL22, and blocking their receptor on differentiation of Th2 cells.

RESULTS

Production of CCL17 and CCL22 by activated naive CD4⁺ T cells under Th2 condition was much more in asthmatic patients than in healthy controls. Proliferation and survival of the Th2 differentiating cells and restimulation-induced IL-4 production were much greater in asthmatic patients than in healthy controls. These cell biological phenomena were inhibited by blockade of CCR4. The biological effects of exogenous CCL17 and CCL22 were apparently observed in both healthy controls and asthmatic patients. The effectiveness of these chemokines on naïve CD4⁺ T cells from healthy controls was stronger than those from asthmatic patients. We found that thymic stromal lymphopoietin (TSLP), a Th2 promoting chemokine, is involved in the activation of CD4⁺ naïve T cells via production of CCL17 and CCL22.

CONCLUSIONS AND CLINICAL RELEVANCE

These data suggest that CCL17 and CCL22 produced by TSLP-primed naïve CD4⁺ T cells in asthma might contribute to an increase in Th2 cells via autocrine loops.

PEG10 as an oncogene: expression regulatory mechanisms and role in tumor progression

Cancer is a major public health problem as one of the leading causes of death worldwide. Deciphering the molecular regulation mechanisms of tumor progression can make way for tumor diagnosis and therapy. Paternally expressed gene 10 (PEG10), located on human chromosome 7q21.3, has turned out to be an oncogene implicated in the proliferation, apoptosis and metastasis of tumors. PEG10 has been found to be positively expressed in a variety of cancers with seemingly complex expression regulation mechanisms. In this review, we focus on the most vital factors influencing PEG10 expression and recapitulate some of the currently known and potential mechanisms of PEG10 affecting tumor progression, as understanding the molecular regulatory mechanisms of tumor progression can provide potential PEG10 related diagnosis and biomarker specific targeted therapies.

Prognostic value of PEG10 in Asian solid tumors: A meta-analysis

BACKGROUND

The involvement of paternally expressed gene 10 (PEG10) in the development of solid tumors has been demonstrated. However, the available data have not yet been fully analyzed. We conducted this meta-analysis to evaluate the correlations between PEG10 and the clinicopathological characteristics in patients with solid tumors.

METHODS

An electronic search for relevant articles was conducted in PubMed, Web of Science, Cochrane Library, EMBASE, Chinese CNKI, and Wan Fang. The relationships between PEG10 and the clinicopathological features and prognosis of patients with cancer were determined using pooled odds ratios and hazard ratios with 95% confidence interval (CI).

RESULTS

Ten studies comprising 1014 patients were included. The pooled analyses indicated the significant association of PEG10 overexpression with the risk of cancer, differentiation, lymph node metastasis and advanced TNM stage, but not with gender in cancer patients. Moreover, a high level of PEG10 expression correlated with poor prognosis and could be used as an independent prognostic biomarker for patients with solid tumors.

CONCLUSIONS

PEG10 expression is associated with advanced clinicopathological characteristics and can be used as a prognostic biomarker in patients with solid tumors.

The role of G protein-coupled receptors in lymphoid malignancies

B cell lymphoma consists of multiple individual diseases arising throughout the lifespan of B cell development. From pro-B cells in the bone marrow, through circulating mature memory B cells, each stage of B cell development is prone to oncogenic mutation and transformation, which can lead to a corresponding lymphoma. Therapies designed against individual types of lymphoma often target features that differ between malignant cells and the corresponding normal cells from which they arise. These genetic changes between tumor and normal cells can include oncogene activation, tumor suppressor gene repression and modified cell surface receptor expression. G protein-coupled receptors (GPCRs) are an important class of cell surface receptors that represent an ideal target for lymphoma therapeutics. GPCRs bind a wide range of ligands to relay extracellular signals through G protein-mediated signaling cascades. Each lymphoma subgroup expresses a unique pattern of GPCRs and efforts are underway to fully characterize these patterns at the genetic level. Aberrations such as overexpression, deletion and mutation of GPCRs have been characterized as having causative roles in lymphoma and such studies describing GPCRs in B cell lymphomas are summarized here.

Microenvironmental agonists generate de novo phenotypic resistance to combined ibrutinib plus venetoclax in CLL and MCL

De novo resistance and rapid recurrence often characterize responses of B-cell malignancies to ibrutinib (IBR), indicating a need to develop drug combinations that block compensatory survival signaling and give deeper, more durable responses. To identify such combinations, we previously performed a combinatorial drug screen and identified the Bcl-2 inhibitor venetoclax (VEN) as a promising partner for combination with IBR in Mantle Cell Lymphoma (MCL). We have opened a multi-institutional clinical trial to test this combination. However, analysis of primary samples from patients with MCL as well as chronic lymphocytic leukemia (CLL) revealed unexpected heterogeneous de novo resistance even to the IBR+VEN combination. In the current study, we demonstrate that resistance to the combination can be generated by microenvironmental agonists: IL-10, CD40L and, most potently, CpG-oligodeoxynucleotides (CpG-ODN), which is a surrogate for unmethylated DNA and a specific agonist for TLR9 signaling. Incubation with these agonists caused robust activation of NF-κB signaling, especially alternative NF-κB, which led to enhanced expression of the anti-apoptotic proteins Mcl-1, Bcl-xL, and survivin, thus decreasing dependence on Bcl-2. Inhibitors of NF-κB signaling blocked overexpression of these anti-apoptotic proteins and overcame resistance. Inhibitors of Mcl-1, Bcl-xL, or survivin also overcame this resistance, and showed synergistic benefit with the IBR+VEN combination. We conclude that microenvironmental factors, particularly the TLR9 agonist, can generate de novo resistance to the IBR+VEN combination in CLL and MCL cells. This signaling pathway presents targets for overcoming drug resistance induced by extrinsic microenvironmental factors in diverse B-cell malignancies.

Coevolution of Leukemia and Host Immune Cells in Chronic Lymphocytic Leukemia

Cumulative studies on the dissection of changes in driver genetic lesions in cancer across the course of the disease have provided powerful insights into the adaptive mechanisms of tumors in response to the selective pressures of therapy and environmental changes. In particular, the advent of next-generation-sequencing (NGS)-based technologies and its implementation for the large-scale comprehensive analyses of cancers have greatly advanced our understanding of cancer as a complex dynamic system wherein genetically distinct subclones interact and compete during tumor evolution. Aside from genetic evolution arising from interactions intrinsic to the cell subpopulations within tumors, it is increasingly appreciated that reciprocal interactions between the tumor cell and cellular constituents of the microenvironment further exert selective pressures on specific clones that can impact the balance between tumor immunity and immunologic evasion and escape. Herein, we review the evidence supporting these concepts, with a particular focus on chronic lymphocytic leukemia (CLL), a disease that has been highly amenable to genomic interrogation and studies of clonal heterogeneity and evolution. Better knowledge of the basis for immune escape has an important clinical impact on prognostic stratification and on the pursuit of new therapeutic opportunities.

PEG10 promotes human breast cancer cell proliferation, migration and invasion

Paternally expressed imprinted gene 10 (PEG10), derived from the Ty3/Gypsy family of retrotransposons, has been implicated as a genetic imprinted gene. Accumulating evidence suggests that PEG10 plays an important role in tumor growth in various cancers, including hepatocellular carcinoma, lung cancer and prostate cancer. However, the correlation between PEG10 and breast cancer remains unclear. In the present study, we evaluated and characterized the role of PEG10 in human breast cancer proliferation, cell cycle, clone formation, migration and invasion. The expression level of PEG10 was significantly elevated in breast cancer tissues and associated with distant metastasis and poor clinical outcome. Gene set enrichment analysis indicated that high expression of PEG10 could enrich cell cycle-related processes in breast cancer tissues. Ectopic overexpression of PEG10 in breast cancer cells enhanced cell proliferation, cell cycle, clone formation along with migration and invasion. Cell-to-cell junction molecule E-cadherin was downregulated and matrix degradation proteases MMP-1, MMP-2, MMP-9 were up-regulated after PEG10 overexpression. Our results demonstrated that PEG10 is a crucial oncogene and has prognostic value for breast cancer, which could be applied in breast cancer diagnosis and targeting therapy in future.

PEG10 plays a crucial role in human lung cancer proliferation, progression, prognosis and metastasis

Paternally expressed gene 10 (PEG10) has been identified as a genetic imprinted gene, which is important for apoptosis resistance in cancer cells. Mounting evidence suggests that PEG10 is expressed in the majority of hepatocellular carcinoma (HCC) cells with growth-promoting activity. In the present study, we evaluated the correlation between PEG10 expression and the clinicopathological features of lung, breast and HCC tumors, and predicted the relationship between survival and expression levels of PEG10 in lung cancer patients. Furthermore, we chose non-small cell lung cancer cell line A549 as a model to analyze the function of PEG10 in proliferation and metastasis in vitro. Our results revealed that expression of PEG10 was closely correlated with clinical TNM grade and patient prognosis in lung cancer. PEG10 enhanced cell proliferation and promoted tumor cell migration and invasion by upregulating the expression of β-catenin, MMP-2 and MMP-9, and decreased the expression of E-cadherin in the A549 cells. Our findings provide significant insight into the molecular mechanisms of lung cancer and offer novel ideas for designing new therapeutic targets for lung carcinoma.

The direct effect of estrogen on cell viability and apoptosis in human gastric cancer cells

Epidemiology researches indicated that gastric cancer is a male-predominant disease; both expression level of estrogen and expression pattern of estrogen receptors (ERs) influence its carcinogenesis. But the direct effect of estrogen on gastric cancer cells is still unclear. This study aimed to explore the direct effect of β-estradiol (E2) on gastric cancer cells. SGC7901 and BGC823 were treated with a serial of concentrations of E2. The survival rates of both the cell lines were significantly reduced, and the reduction of viability was due to apoptosis triggered by E2 treatment. Caspase 3 was activated in response to the increasing E2 concentration in both SGC7901 and BGC823. Cleaved Caspase 3 fragments were detected, and the expression levels of Bcl-2 and Bcl-xL were reduced. Apoptosis was further confirmed by flow cytometry. The expression level of PEG10, an androgen receptor target gene, was reduced during E2 treatment. Both ERα and ERβ were expressed in these cell lines, and the result of bioinformatics analysis of gastric cancer from GEO datasets indicated that the expression levels of both ERα and ERβ were significantly higher in noncancerous gastric tissues than in gastric cancer tissues. Our research indicated that estrogen can reduce cell viability and promote apoptosis in gastric cancer cells directly; ERs expression level is associated with gastric cancer. Our research will help to understand the mechanism of gender disparity in gastric cancer.

Immunotherapy of B-cell non-Hodgkin lymphoma by targeting the chemokine receptor CXCR5 in a preclinical mouse model

Bispecific antibodies are promising agents for immunotherapy. Here, we describe a quadroma-based trifunctional bispecific antibody binding the chemokine receptor CXCR5 and the T-cell antigen CD3 that efficiently prevents tumor growth in a mouse B-cell lymphoma model. CXCR5 regulates the tissue homeostasis of mature B cells and is highly expressed on B-cell non-Hodgkin and lymphocyte-predominant Hodgkin lymphoma, as well as on a subset of CD4(+) T cells known as follicular T-helper cells. In vitro, the bispecific CXCR5::CD3 antibody efficiently recruited effector T cells to CXCR5 expressing B cells and induced a co-stimulation-independent activation of CD8(+) and CD4(+) T cells as demonstrated by the de novo expression of CD25 and CD69, and secretion of the cytokines IFN-γ, TNF-α, IL-6 and IL-10 by peripheral blood mononuclear cells. Notably, at low antibody concentrations, CXCR5::CD3 displayed a significantly higher cytotoxic activity against autologous B cells than its parental antibodies or rituximab. In vivo imaging revealed that CXCR5::CD3 and its parental CXCR5 antibody efficiently prevent tumor growth in a xenograft model of B-cell lymphoma in mice and prolong their survival. Taken together, our results identify CXCR5 as a promising target for antibody-based therapies in the treatment of B-cell malignancies.

TSG101 and PEG10 are prognostic markers in squamous cell/adenosquamous carcinomas and adenocarcinoma of the gallbladder

The clinicopathological characteristics of squamous cell/adenosquamous carcinoma (SC/ASC) are currently not well documented, and as the prevalence of SC/ASC is uncommon in gallbladder cancers, a prognostic marker has not yet been found. In the present study, the expression of tumor susceptibility gene (TSG) 101 and paternally expressed gene (PEG) 10 was assessed in 46 SC/ASCs and 80 adenocarcinomas (ACs) using immunohistochemistry, and the samples were further analyzed to examine correlations with the clinicopathological characteristics. It was demonstrated that positive TSG101 and PEG10 expression were significantly associated with large tumor size, high tumor-node-metastasis (TNM) stage, lymph node metastasis, invasion and no resection (only biopsy) of SC/ASC and AC. The univariate Kaplan-Meier analysis showed that positive TSG101 and PEG10 expression, and differentiation, tumor size, TNM stage, lymph node metastasis, invasion and surgical curability, is closely associated with a decreased overall survival in SC/ASC and AC patients (P<0.05 or P<0.001). The multivariate Cox regression analysis identified that positive TSG101 and PEG10 expression are independent factors for a poor-prognosis in SC/ASC and AC patients. The present study indicates that positive TSG101 and PEG10 expression are closely associated with the clinical, pathological and biological behaviors, and a poor prognosis in gallbladder cancer.

Beyond high-dose methotrexate and brain radiotherapy: novel targets and agents for primary CNS lymphoma

BACKGROUND

While there has been significant progress in outcomes for patients diagnosed with primary central nervous system (CNS) lymphoma (PCNSL), survival rates will likely plateau with the current armamentarium of agents used to treat these patients. Moreover, given that PCNSL increasingly impacts an older population, a significant proportion of patients are not eligible for intensive therapies such as high-dose chemotherapy or whole-brain radiation. There is a need for the development of novel agents, which target key survival pathways in order to continue to make progress in this disease.

PATIENTS AND METHODS

We reviewed the key molecular pathways and genomic aberrations in PCNSL in order to identify candidate targets. We focused on molecules and pathways that have been identified and confirmed by more than one investigator or methodology.

RESULTS

While PCNSL tumors usually express a BCL6+, MUM1+ 'activated, germinal center' immunophenotype, they exhibit multiple shared genetic properties with ABC-type diffuse large B-cell lymphomas. Candidate targets and pathways include NFkB, the B-cell receptor, the JAK/STAT pathway, IRF4, BCL-6 as well as PIM kinases. Elements of the tumor microenvironment that may be exploited therapeutically include chemokine pathways, as well as macrophage and T-cell responses.

CONCLUSIONS

There is a significant need for developing novel therapies in PCNSL, given that an increasing proportion of patients are not eligible for high-dose chemotherapy and brain radiation is associated with detrimental cognitive side-effects. We provide an overview of potential drug targets and novel agents that may be integrated with existing strategies in order to make further progress in this disease.

Biology of chronic lymphocytic leukemia in different microenvironments: clinical and therapeutic implications

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of mature monoclonal B cells in peripheral blood, bone marrow, spleen, and lymph nodes. The trafficking, survival, and proliferation of CLL cells is tightly regulated by the surrounding tissue microenvironment and is mediated by antigenic stimulation, close interaction with various accessory cells and exposure to different cytokines, chemokines, and extracellular matrix components. In the last decade there have been major advances in the understanding of the reciprocal interactions between CLL cells and the various microenvironmental compartments. This article discusses the role of the microenvironment in the context of efforts to develop novel therapeutics that target the biology of CLL.

CXCL13 plus interleukin 10 is highly specific for the diagnosis of CNS lymphoma

Establishing the diagnosis of focal brain lesions in patients with unexplained neurologic symptoms represents a challenge. The goal of this study is to provide evidence supporting functional roles for CXC chemokine ligand (CXCL)13 and interleukin (IL)-10 in central nervous system (CNS) lymphomas and to evaluate the utility of each as prognostic and diagnostic biomarkers. We demonstrate for the first time that elevated CXCL13 concentration in cerebrospinal fluid (CSF) is prognostic and that CXCL13 and CXCL12 mediate chemotaxis of lymphoma cells isolated from CNS lymphoma lesions. Expression of the activated form of Janus kinase 1 supported a role for IL-10 in prosurvival signaling. We determined the concentration of CXCL13 and IL-10 in CSF of CNS lymphoma patients and control cohorts including inflammatory and degenerative neurologic disease in a multicenter study involving 220 patients. Bivariate elevated CXCL13 plus IL-10 was 99.3% specific for primary and secondary CNS lymphoma, with sensitivity significantly greater than reference standard CSF tests. These results identify CXCL13 and IL-10 as potentially important biomarkers of CNS lymphoma that merit further evaluation and support incorporation of CXCL13 and IL-10 into diagnostic algorithms for the workup of focal brain lesions in which lymphoma is a consideration.

Invited commentary: childhood acute lymphoblastic leukemia and allergies: biology or bias?

Previous epidemiologic studies have shown an inverse association between a personal history of atopy/allergies, both overall and among asthma, eczema, and hay fever investigated separately, and childhood acute lymphoblastic leukemia (ALL) with some consistency; however, in most of these studies, exposure data were collected by maternal interview. Now, in a population-based and records-based study in this issue of the Journal (Am J Epidemiol. 2012;176(11):970-978), Chang et al. report an increased risk for allergic conditions across different etiologic time periods, calling the former paradigm into doubt. A review of the basic biology literature shows that proposed mechanisms support either a positive or an inverse association. In light of this ambiguity, it is epidemiology's turn to determine the direction of association.

Homeostatic chemokines guide lymphoma cells to tumor growth-promoting niches within secondary lymphoid organs

The interaction between lymphoid tumor cells and their tissue microenvironment is thought to promote dissemination and progression of lymphoma. Those type of interactions consists of at least three cornerstones, among them mesenchymal- or bone marrow-derived stromal cells, cells of the innate or adaptive immune response, and the lymphoma cells themselves. The molecular pathways of crosstalk between the lymphoma cells and their nursing stroma are not well understood and their dissection is challenging because of (1) the complexity of stroma cell subpopulations, (2) kinetic and developmental transitions/switches of stroma composition, and (3) inherent technical difficulties to isolate and analyze defined stroma cell subsets. However, recent studies of bone marrow stroma interaction with leukemia or lymphoma cells have revealed therapeutic targets involved in regulating tumor cell mobilization. Release of tumor cells from their supportive niches could be effectuated by inhibition of homing and retention signals. The present review focuses on the effects of homing receptors and cytokines attributed to lymphoid tissue formation in tumor-stroma interactions within secondary lymphoid tissues. We discuss possible cellular and molecular mechanisms of lymphoma-stroma crosstalk and highlight novel therapeutic strategies based on the disruption of tumor-stroma interaction in secondary lymphoid organs.

CCL2 and CXCL2 enhance survival of primary chronic lymphocytic leukemia cells in vitro

Chronic lymphocytic leukemia (CLL) is predominantly a disease of accumulation rather than rapid proliferation. To date, no cell lines exist, as CLL cells undergo rapid apoptosis when cultured in vitro, suggesting that a favorable in vivo microenvironment is required. To identify survival signals we cultured primary CLL peripheral blood mononuclear cells (PBMCs) at high density, which has previously been shown to dramatically improve survival. Using antibody arrays we measured the level of 42 cytokines in culture supernatants and showed that inerleukin-6 (IL-6), IL-8, CXCL2 and CCL2 were highly up-regulated in culture. This is the first report to describe a role for CCL2 and CXCL2 in CLL cell survival. Importantly, CXCL2, IL-6 and IL-8 were significantly up-regulated in primary patient plasma. The addition of either CXCL2 or CCL2 enhanced CLL cell survival, while antibodies blocking these chemokines reduced survival. Co-culture of CLL cells and PBMC accessory cells separated by transwells provided a similar degree of survival protection compared to normal culture, whereas CLL cells cultured alone died rapidly. Interestingly, CCL2 and CXCL2 appeared to be produced by CLL cells but only when co-cultured with accessory cells. Thus, we speculate that accessory cells release soluble factors that promote the production of these pro-survival chemokines from CLL cells and physical interactions are not required. Our data support the concept that the CLL microenvironment is critical, and suggests that soluble factors are more important than physical interactions.

Chemokine-dependent B cell-T cell interactions in chronic lymphocytic leukemia and multiple myeloma - targets for therapeutic intervention?

INTRODUCTION

Chemokines and their receptors play essential roles in the development, maintenance and proper functioning of the immune system. B cell-T cell interactions are modulated by chemokines. In B cell malignancies, these interactions may have tumor-promoting consequences.

AREAS COVERED

This review summarizes physiological B cell-T cell interactions and discusses their pathological role in the onset and progression of B cell malignancies with a special focus on chronic lymphocytic leukemia and multiple myeloma. Experimental data on chemokine-guided B cell-T cell actions in B cell malignancies from murine models as well as in vitro data are summarized and their potential as future therapeutic targets is critically discussed.

EXPERT OPINION

Direct or indirect targeting of chemokine receptors involved in localization and T-cell-dependent activation of B lymphocytes can provide strong synergisms with conventional or immunomodulatory therapies by disrupting the microenvironmental conditions necessary for survival and proliferation of malignant B lymphocytes. However, further knowledge of these interactions between B and T cells is needed.

ZAP-70 enhances migration of malignant B lymphocytes toward CCL21 by inducing CCR7 expression via IgM-ERK1/2 activation

ZAP-70 in chronic lymphocytic leukemia (CLL) has been associated with enhanced B-cell receptor (BCR) signaling, survival, and migration. We investigated whether ZAP-70 can directly govern migration and the underlying mechanisms. In the ZAP-70 stably transfected Ramos cell line, IgM stimulation, but no IgD, enhanced phosphorylation of ERK1/2, Akt and Syk, and delayed IgM and CD79b internalization. In contrast, in the Raji cell line, where ZAP-70 was constitutively phosphorylated, ERK1/2, but not Akt, was phosphorylated, suggesting that MAPK pathway mediates ZAP-70 effects. BCR stimulation modulated the expression of CCR7, CXCR4, CXCR5, CD44, CD49d, and CD62L, which were up-regulated in ZAP-70-positive CLL primary subclones. The most dramatic change after BCR engagement in ZAP-70-transfected cells was CCR7 up-regulation, this being impaired by ERK1/2 inhibition and translating into both increased signaling and migration toward CCL21. Primary CLL subclones with high ZAP-70 expression showed increased migration toward CCL21. In conclusion, ZAP-70 ectopic expression led to enhanced BCR signaling after IgM stimulation and increased the expression of CCR7 predominantly via ERK1/2, increasing the response and migration toward CCL21. In primary CLL samples, cellular subsets with high ZAP-70 expression had increased expression of adhesion molecules and chemokine receptors in addition to an enhanced ability to migrate toward CCL21.

Lack of chemokine signaling through CXCR5 causes increased mortality, ventricular dilatation and deranged matrix during cardiac pressure overload

RATIONALE

Inflammatory mechanisms have been suggested to play a role in the development of heart failure (HF), but a role for chemokines is largely unknown. Based on their role in inflammation and matrix remodeling in other tissues, we hypothesized that CXCL13 and CXCR5 could be involved in cardiac remodeling during HF.

OBJECTIVE

We sought to analyze the role of the chemokine CXCL13 and its receptor CXCR5 in cardiac pathophysiology leading to HF.

METHODS AND RESULTS

Mice harboring a systemic knockout of the CXCR5 (CXCR5(-/-)) displayed increased mortality during a follow-up of 80 days after aortic banding (AB). Following three weeks of AB, CXCR5(-/-) developed significant left ventricular (LV) dilatation compared to wild type (WT) mice. Microarray analysis revealed altered expression of several small leucine-rich proteoglycans (SLRPs) that bind to collagen and modulate fibril assembly. Protein levels of fibromodulin, decorin and lumican (all SLRPs) were significantly reduced in AB CXCR5(-/-) compared to AB WT mice. Electron microscopy revealed loosely packed extracellular matrix with individual collagen fibers and small networks of proteoglycans in AB CXCR5(-/-) mice. Addition of CXCL13 to cultured cardiac fibroblasts enhanced the expression of SLRPs. In patients with HF, we observed increased myocardial levels of CXCR5 and SLRPs, which was reversed following LV assist device treatment.

CONCLUSIONS

Lack of CXCR5 leads to LV dilatation and increased mortality during pressure overload, possibly via lack of an increase in SLRPs. This study demonstrates a critical role of the chemokine CXCL13 and CXCR5 in survival and maintaining of cardiac structure upon pressure overload, by regulating proteoglycans essential for correct collagen assembly.

Identification of PEG10 and TSG101 as carcinogenesis, progression, and poor-prognosis related biomarkers for gallbladder adenocarcinoma

PEG10 is a transcriptional factor while TSG101 is involved in numerous cellular processes, including apoptotic resistance. Overexpression of PEG10 and TSG101 were observed in a variety of human cancers. However, their expression and clinical significance in gallbladder cancer (GBC) have not yet been identified. To understand the tumor biology of GBC at the molecular level, we examined PEG10 and TSG101 expression in 108 adenocarcinomas, 15 gallbladder polyps, 35 chronic cholecystitis tissues, and 46 peritumoral tissues by using immunohistochemistry. Overexpression of PEG10 and TSG101 was detected in gallbladder adenocarcinoma (48.1% and 47.2%, respectively). Conversely, there was less expression detected in the peritumoral tissues (19.6%), adenomatous polyps (13.3%), and gallbladder epithelium with chronic cholecystitis (5.1%) (p < 0.01, p < 0.05, and p < 0.01, respectively). Notably, the benign lesions with positive PEG10 and/or TSG101 expression showed moderately or severely atypical hyperplasia in gallbladder epithelium. The overexpression of PEG10 and TSG101 was significantly associated with differentiation, tumor mass, lymph node metastasis and invasion of adenocarcinoma. Univariate Kaplan-Meier analysis showed that overexpression of PEG10 (p = 0.041) and TSG101 (p = 0.025) was closely associated with decreased overall survival. Multivariate Cox regression analysis revealed that positive expression of PEG10 (p = 0.036) or TSG101 (p = 0.022) is a predictor of poor prognosis in gallbladder adenocarcinoma. Our study suggested that overexpression of PEG10 and TSG101 might be closely related to the carcinogenesis, progression, clinical biological behaviors, and prognosis of gallbladder adenocarcinoma.

Role of the atypical chemoattractant receptor CRAM in regulating CCL19 induced CCR7 responses in B-cell chronic lymphocytic leukemia

Background

The non-signalling chemokine receptors, including receptors DARC, D6 and CCX-CKR, have recently been shown to be involved in chemokine clearance and activity regulation. The human chemokine receptor CRAM (also known as HCR or CCRL2) is the most recently identified member of this atypical group. CRAM is expressed on B cells in a maturation-stage dependent manner and absent on T cells. We have recently shown that it competitively binds CCL19. CCL19 and its signalling receptor CCR7 are critical components involved in cell recruitment to secondary lymphoid organs and in maturation. B cell Chronic Lymphocytic Leukemia (B-CLL) is a low-grade lymphoma characterized by proliferative centres (or pseudofollicles). Proliferative centres develop due to abnormal cellular localisation and they are involved in the development of malignant cells. CCR7 is highly expressed on B cells from CLL patients and mediates migration towards its ligands CCL19 and CCL21, while CRAM expression and potential interferences with CCR7 are yet to be characterized.

Results

In this study, we show that B cells from patients with B-CLL present highly variable degrees of CRAM expression in contrast to more consistently high levels of CCR7. We investigated the hypothesis that, similar to the atypical receptor DARC, CRAM can modulate chemokine availability and/or efficacy, resulting in the regulation of cellular activation. We found that a high level of CRAM expression was detrimental to efficient chemotaxis with CCL19. MAP-kinase phosphorylation and intracellular calcium release induced by CCL19 were also altered by CRAM expression. In addition, we demonstrate that CRAM-induced regulation of CCL19 signalling is maintained over time.

Conclusions

We postulate that CRAM is a factor involved in the fine tuning/control of CCR7/CCL19 mediated responses. This regulation could be critical to the pivotal role of CCL19 induced formation of proliferation centres supporting the T/B cells encounter as well as disease progression in B-CLL.

The role of chemokines in B cell chronic lymphocytic leukaemia: pathophysiological aspects and clinical impact

Chemokines are centrally involved in leukocyte migration, homing and haematopoiesis. Besides these physiological aspects, their role in pathological processes especially with respect to solid tumour and haematological neoplasias is well established. In this context, the focus was set here on disclosing their contribution in B cell chronic lymphocytic leukaemia (B-CLL), which is regarded as the most characteristic low-grade lymphoma. Up to now, it has been demonstrated that several chemokines are involved in migration of B-CLL cells to lymph nodes, secondary lymphoid organs and bone marrow. Moreover, some chemokines are known to have an anti-apoptotic effect and thus contribute to the survival of B-CLL cells. By interfering with both of these aspects, new therapeutic targets for this yet incurable disease may be developed. Furthermore, a correlation can be drawn between the concentration of some chemokines in patients' serum, the expression of their respective receptors on B-CLL cells and well-established predictive clinical parameters. Consequently, further systematic investigation of the chemokine network may lead to the identification of new diagnostic and prognostic markers. This review focuses on the impact of chemokines and their receptors on B-CLL pathophysiology and points out potential implications for both treatment and diagnosis.

CXCL13 and CXCL12 in central nervous system lymphoma patients

PURPOSE

Homing of malignant lymphocytes to the central nervous system (CNS) may play a role in the pathogenesis of CNS lymphoma. In this study, we evaluated the chemokines CXCL12 and CXCL13 in the cerebrospinal fluid (CSF) and serum of patients with CNS lymphoma.

EXPERIMENTAL DESIGN

Samples from 30 patients with CNS lymphoma (23 with primary and 7 with secondary CNS lymphoma; all B-cell lymphoma) and 40 controls (10 patients with other CNS malignancies and 30 without a malignant CNS disease) were examined. CXCL12 and CXCL13 concentrations were measured using enzyme-linked immunosorbent assays. The grade of blood-brain barrier disruption was estimated by the CSF/serum albumin ratio.

RESULTS

CNS lymphoma patients and controls did not differ in CXCL12 serum and CSF levels. Serum levels of CXCL13 were generally low. CXCL13 CSF levels, however, were significantly higher in CNS lymphoma patients as compared with controls (P < 0.0001). Chemokine levels in CSF and serum did not correlate. In CNS lymphoma, CXCL13 concentration in CSF correlated with the degree of blood-brain barrier disruption (R = 0.66; P = 0.003). Elevated CSF levels of CXCL12 and CXCL13 measured in seven CNS lymphoma patients during therapy decreased in five patients who responded to chemotherapy and increased in two with lymphoma progression.

CONCLUSIONS

Our results suggest a production of CXCL13 within the CNS of CNS lymphoma patients, which decreases with response to therapy. Thus, CXCL13 may represent a marker for further diagnostic and prognostic studies.

Modulation of chemokine receptor activity through dimerization and crosstalk

Chemokines are small, secreted proteins that bind to the chemokine receptor subfamily of class A G protein-coupled receptors. Collectively, these receptor-ligand pairs are responsible for diverse physiological responses including immune cell trafficking, development and mitogenic signaling, both in the context of homeostasis and disease. However, chemokines and their receptors are not isolated entities, but instead function in complex networks involving homo- and heterodimer formation as well as crosstalk with other signaling complexes. Here the functional consequences of chemokine receptor activity, from the perspective of both direct physical associations with other receptors and indirect crosstalk with orthogonal signaling pathways, are reviewed. Modulation of chemokine receptor activity through these mechanisms has significant implications in physiological and pathological processes, as well as drug discovery and drug efficacy. The integration of signals downstream of chemokine and other receptors will be key to understanding how cells fine-tune their response to a variety of stimuli, including therapeutics.

Association between decreased CXCL12 and CCL25 expression and increased apoptosis in lymphoid tissues of cynomolgus macaques during SIV infection

BACKGROUND

Chemokines likely play multiple roles in HIV-1 and SIV pathogenesis. To examine potential associations between chemokine expression levels and apoptosis of cells in lymphoid tissues during SIV infection, we measured chemokine and cytokine mRNA levels in multiple lymphoid tissues compartments from uninfected and SIV-infected cynomolgus macaques (Macaca fascicularis).

METHODS

Real-time RT-PCR was used to measure host mRNA levels in macaque lymphoid tissues. Proliferating or apoptotic cells were identified in lymphoid tissues by immunohistochemistry.

RESULTS

We found that CXCL12 and CCL25 mRNAs in SIV-infected lymphoid tissues were decreased and their levels were negatively correlated with the numbers of proliferating and apoptotic cells. In vitro analyses revealed that CXCL12 and CCL25 were capable of reducing apoptosis induced by SIV infection.

CONCLUSIONS

These findings suggest that increased apoptosis in lymphoid tissues due to reduced levels of anti-apoptotic chemokines might be a mechanism that contributes to loss of immune function following pathogenic SIV infection.

Chemokine CXCL13 is overexpressed in the tumour tissue and in the peripheral blood of breast cancer patients

The abilities of chemokines in orchestrating cellular migration are utilised by different (patho-)biological networks including malignancies. However, except for CXCR4/CXCL12, little is known about the relation between tumour-related chemokine expression and the development and progression of solid tumours like breast cancer. In this study, microarray analyses revealed the overexpression of chemokine CXCL13 in breast cancer specimens. This finding was confirmed by real-time polymerase chain reaction in a larger set of samples (n=34) and cell lines, and was validated on the protein level performing Western blot, ELISA, and immunohistochemistry. Levels of CXCR5, the receptor for CXCL13, were low in malignant and healthy breast tissues, and surface expression was not detected in vitro. However, we observed a strong (P=0.0004) correlation between the expressions of CXCL13 and CXCR5 in breast cancer tissues, indicating a biologically relevant role of CXCR5 in vivo. Finally, we detected significantly elevated serum concentrations of CXCL13 in patients with metastatic disease (n=54) as compared with controls (n=44) and disease-free patients (n=48). In conclusion, CXCL13 is overexpressed within breast cancer tissues, and increased serum levels of this cytokine can be found in breast cancer patients with metastatic disease pointing to a role of CXCL13 in the progression of breast cancer, suggesting that CXCL13 might serve as a useful therapeutic target and/or diagnostic marker in this malignancy.