Increased B cell-activating factor promotes tumor invasion and metastasis in human pancreatic cancer

Past and present discovery of the BAFF/APRIL system - A bibliometric study from 1999 to 2023

Cytokines from the Tumour Necrosis Factor (TNF) family are important regulators of both physiological and pathological processes. The discovery of novel TNF ligands and receptors, BAFF and APRIL, have opened up new possibilities for scientists to explore the effect of these cytokines on the human immune system. The role of BAFF/APRIL system in B lymphocytes is particularly important for survival and maintenance of homeostasis. Aberrant expression of the system is associated with various immunological disorders. Hence, this study provides a comprehensive overview of the past and present BAFF/APRIL system research development in a bibliometric perspective. To our best knowledge, this is the first ever bibliometric analysis conducted focusing on the BAFF/APRIL system. A total of 1055 relevant documents were retrieved from WoSCC. Microsoft Excel, VOSviewer, and Biblioshiny of R studio were bibliometric tools used to analyse the scientific literature. From 1999, the annual publications showed an upward trend, with Journal of Immunology being the most productive journal. USA leads the race for BAFF/APRIL system research developments. Pascal Schneider, a senior researcher affiliated with University of Lausanne, Switzerland was recognised as the most productive author and institution in the BAFF/APRIL system research field. The research focus transitioned from focusing on the role of the system in B cell biology, to immunological disorders and finally to development of BAFF/APRIL targeting drugs. Despite several studies elucidating briefly the pathway mechanism of BAFF/APRIL system in B-cell selection, substantial research on the mechanism of action in disease models and T cell activation and development of immunomodulating drugs from natural origins remains largely unexplored. Therefore, future research focusing on these areas are crucial for the deeper understanding of the system in disease manifestations and progression allowing a better treatment management for various immunological disorders.

Pyroptosis is involved in the immune microenvironment regulation of unexplained recurrent miscarriage

Unexplained recurrent miscarriage (URM) is a common pregnancy complication with few effective therapies. Moreover, little is known regarding the role of pyroptosis in the regulation of the URM immune microenvironment. To address this issue, gene expression profiles of publicly available placental datasets GSE22490 and GSE76862 were downloaded from the Gene Expression Omnibus database. Pyroptosis-related differentially expressed genes were identified and a total of 16 differentially expressed genes associated with pyroptosis were detected, among which 1 was upregulated and 15 were downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that the functionally enriched modules and pathways of these genes are closely related to immune and inflammatory responses. Four hub genes were identified: BTK, TLR8, NLRC4, and TNFSF13B. BTK, TLR8, and TNFSF13B were highly connected with immune cells, according to the correlation analysis of four hub genes and 20 different types of immune cells (p < 0.05). The four hub genes were used as research objects to construct the interaction networks. Chorionic villus tissue was used for quantitative real-time polymerase chain reaction and western blot to confirm the expression levels of hub genes, and the results showed that the expression of the four hub genes was significantly decreased in the chorionic villus tissue in the URM group. Collectively, the present study indicates that perhaps pyroptosis is essential to the diversity and complexity of the URM immune microenvironment, and provides a theoretical basis and research ideas for subsequent target gene verification and mechanism research.

Key processes in tumor metastasis and therapeutic strategies with nanocarriers: a review

Cancer metastasis is the leading cause of cancer-related death. Metastasis occurs at all stages of tumor development, with unexplored changes occurring at the primary site and distant colonization sites. The growing understanding of the metastatic process of tumor cells has contributed to the emergence of better treatment options and strategies. This review summarizes a range of features related to tumor cell metastasis and nanobased drug delivery systems for inhibiting tumor metastasis. The mechanisms of tumor metastasis in the ideal order of metastatic progression were summarized. We focus on the prominent role of nanocarriers in the treatment of tumor metastasis, summarizing the latest applications of nanocarriers in combination with drugs to target important components and processes of tumor metastasis and providing ideas for more effective nanodrug delivery systems.

The Evolving Landscape of B Cells in Cancer Metastasis

Metastasis is the leading cause of cancer mortality. Functional and clinical studies have documented diverse B-cell and antibody responses in cancer metastasis. The presence of B cells in tumor microenvironments and metastatic sites has been associated with diverse effects that can promote or inhibit metastasis. Specifically, B cells can contribute to the spread of cancer cells by enhancing tumor cell motility, invasion, angiogenesis, lymphangiogenesis, and extracellular matrix remodeling. Moreover, they can promote metastatic colonization by triggering pathogenic immunoglobulin responses and recruiting immune suppressive cells. Contrastingly, B cells can also exhibit antimetastatic effects. For example, they aid in enhanced antigen presentation, which helps activate immune responses against cancer cells. In addition, B cells play a crucial role in preventing the dissemination of metastatic cells from the primary tumor and secrete antibodies that can aid in tumor recognition. Here, we review the complex roles of B cells in metastasis, delineating the heterogeneity of B-cell activity and subtypes by metastatic site, antibody class, antigen (if known), and molecular phenotype. These important attributes of B cells emphasize the need for a deeper understanding and characterization of B-cell phenotypes to define their effects in metastasis.

Expression of Immune-Related and Inflammatory Markers and Their Prognostic Impact in Colorectal Cancer Patients

The tumor microenvironment of colorectal cancer (CRC) is heterogenous; thus, it is likely that multiple immune-related and inflammatory markers are simultaneously expressed in the tumor. The aim of this study was to identify immune-related and inflammatory markers expressed in freshly frozen CRC tissues and to investigate whether they are related to the clinicopathological features and prognosis of CRC. Seventy patients with CRC who underwent curative surgical resection between December 2014 and January 2017 were included in this study. Tissue samples were obtained from tumor and non-tumor areas in the patients' colons. The concentrations of immune-related markers (APRIL/TNFSF13, BAFF, LAG-3, PD-1, PD-L1, and CTLA-4) and inflammatory markers (CHIT, MMP-3, osteocalcin, pentraxin-3, sTNF-R1, and sTNF-R2) in the samples were measured using the Bio-plex Multiplex Immunoassay system. The concentrations of APRIL/TNFSF13, BAFF, and MMP-3 in the samples were significantly high; thus, we conducted analyses based on the cut-off values for these three markers. The high-APRIL/TNFSH13-expression group showed a significantly higher rate of metastatic lesions than the low-expression group, whereas the high-MMP-3-expression group had higher CEA levels, more lymph node metastases, and more advanced disease stages than the low-expression group. The five-year disease-free survival of the high-MMP-3-expression group was significantly shorter than that of the low-expression group (65.1% vs. 90.2%, p = 0.033). This study provides evidence that the APRIL/TNFSF13, BAFF, and MMP-3 pathway is overexpressed in CRC tissues and is associated with unfavorable clinicopathological features and poor prognosis in CRC patients. These markers could serve as diagnostic or prognostic biomarkers for CRC.

The BAFF-APRIL System in Cancer

B cell-activating factor (BAFF; also known as CD257, TNFSF13B, BLyS) and a proliferation-inducing ligand (APRIL; also known as CD256, TNFSF13) belong to the tumor necrosis factor (TNF) family. BAFF was initially discovered as a B-cell survival factor, whereas APRIL was first identified as a protein highly expressed in various cancers. These discoveries were followed by over two decades of extensive research effort, which identified overlapping signaling cascades between BAFF and APRIL, controlling immune homeostasis in health and driving pathogenesis in autoimmunity and cancer, the latter being the focus of this review. High levels of BAFF, APRIL, and their receptors have been detected in different cancers and found to be associated with disease severity and treatment response. Here, we have summarized the role of the BAFF-APRIL system in immune cell differentiation and immune tolerance and detailed its pathogenic functions in hematological and solid cancers. We also highlight the emerging therapeutics targeting the BAFF-APRIL system in different cancer types.

Spatial genomics reveals a high number and specific location of B cells in the pancreatic ductal adenocarcinoma microenvironment of long-term survivors

Background and aim

Only 10% of pancreatic ductal adenocarcinoma (PDAC) patients survive longer than five years. Factors underlining long-term survivorship in PDAC are not well understood. Therefore, we aimed to identify the key players in the tumor immune microenvironment (TIME) associated with long-term survivorship in PDAC patients.

Methods

The immune-related gene expression profiles of resected PDAC tumors of patients who survived and remained recurrence-free of disease for ≥36 months (long-term survivors, n=10) were compared to patients who had survived ≤6 months (short-term survivors, n=10) due to tumor recurrence. Validation was performed by the spatial protein expression profile of immune cells using the GeoMx™ Digital Spatial Profiler. An independent cohort of samples consisting of 12 long-term survivors and 10 short-term survivors, was used for additional validation. The independent validation was performed by combining qualitative immunohistochemistry and quantitative protein expression profiling.

Results

B cells were found to be significantly increased in the TIME of long-term survivors by gene expression profiling (p=0.018). The high tumor infiltration of B cells was confirmed by spatial protein profiling in the discovery and the validation cohorts (p=0.002 and p=0.01, respectively). The higher number of infiltrated B cells was found mainly in the stromal compartments of PDAC samples and was exclusively found within tumor cells in long-term survivors.

Conclusion

This is the first comprehensive study that connects the immune landscape of gene expression profiles and protein spatial infiltration with the survivorship of PDAC patients. We found a higher number and a specific location of B cells in TIME of long-term survivors which emphasizes the importance of B cells and B cell-based therapy for future personalized immunotherapy in PDAC patients.

BAFF Attenuates Immunosuppressive Monocytes in the Melanoma Tumor Microenvironment

Emerging evidence indicates B-cell activating factor (BAFF, Tnfsf13b) to be an important cytokine for antitumor immunity. In this study, we generated a BAFF-overexpressing B16.F10 melanoma cell model and found that BAFF-expressing tumors grow more slowly in vivo than control tumors. The tumor microenvironment (TME) of BAFF-overexpressing tumors had decreased myeloid infiltrates with lower PD-L1 expression. Monocyte depletion and anti-PD-L1 antibody treatment confirmed the functional importance of monocytes for the phenotype of BAFF-mediated tumor growth delay. RNA sequencing analysis confirmed that monocytes isolated from BAFF-overexpressing tumors were characterized by a less exhaustive phenotype and were enriched for in genes involved in activating adaptive immune responses and NF-κB signaling. Evaluation of patients with late-stage metastatic melanoma treated with inhibitors of the PD-1/PD-L1 axis demonstrated a stratification of patients with high and low BAFF plasma levels. Patients with high BAFF levels experienced lower responses to anti-PD-1 immunotherapies. In summary, these results show that BAFF, through its effect on tumor-infiltrating monocytes, not only impacts primary tumor growth but can serve as a biomarker to predict response to anti-PD-1 immunotherapy in advanced disease. SIGNIFICANCE: The BAFF cytokine regulates monocytes in the melanoma microenvironment to suppress tumor growth, highlighting the importance of BAFF in antitumor immunity.

The effects of BAFF and APRIL signaling on non-small cell lung cancer cell proliferation and invasiveness

Lung cancer represents the most common type of human malignancy and is the main cause of cancer-associated mortality worldwide. To improve the effectiveness of treatment strategies, a better understanding of the mechanisms of cancer progression and invasiveness is required. Recently, B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL), two relatively newly described cytokines belonging to the tumor necrosis factor superfamily, have been shown to play a role in cancer progression. However, at present, the effects of both cytokines on lung cancer cells remain unclear. The present study aimed therefore to understand the direct effects of BAFF and APRIL on non-small cell lung cancer (NSCLC) progression. To do so, reverse transcription quantitative PCR and western blotting were used to evaluate whether A549 and H2030 NSCLC cells express receptors for both BAFF and APRIL. The results demonstrated that both investigated cell lines expressed BAFF-R (receptor specific to BAFF only) and transmembrane activator and CAML interactor (TACI; shared receptor for both cytokines). In addition, functional experiments were performed to determine the effects of BAFF and APRIL stimulation on cancer cell viability. The results demonstrated no direct effects of BAFF and APRIL on NSCLC cell proliferation and invasiveness. In summary, the present study demonstrated that NSCLC cells possess the ability to respond directly to both BAFF and APRIL. However, activation of BAFF-R and TACI signaling in cancer cells did not increase the proliferative capacity and invasiveness. Further investigation is thus required to better understand the role of BAFF and APRIL on the progression of NSCLC.

Evaluation of a Three-Marker Panel for the Detection of Uveal Melanoma Metastases: A Single-Center Retrospective Analysis

Simple Summary

Blood-based B-cell activating factor (BAFF), growth differentiation factor-15 (GDF-15) and osteopontin (OPN) have been reported to be biomarkers for the uveal melanoma (UM) metastases. This work intended to assess their kinetics and to evaluate their significance as a three-marker panel for clinical practice. Our results not only provided their cutoff values for differentiating the metastatic patients from non-metastatic patients, but also confirmed that the three-marker panel outperformed any single biomarker in distinguishing metastatic patients. Besides, the increasing trends of the levels of three biomarkers were detected in the two-year period before the imaging diagnosis of metastases. The multiplex panel of BAFF, GDF-15 and OPN might be a utilizable implementation for the detection of UM metastases. Since it is a retrospective pilot work, more well-designed prospective studies employing larger cohorts are still needed to validate the findings.

Abstract

Blood-based B-cell activating factor (BAFF), growth differentiation factor-15 (GDF-15) and osteopontin (OPN) have been identified to be promising biomarkers for the metastases of uveal melanoma (UM). This study intended to assess their kinetics and to evaluate their significance as a three-marker panel. A group of 36 UM patients with and 137 patients without metastases were included in the study. Their plasma OPN levels were measured by ELISA; serum BAFF and GDF-15 levels were determined with a Luminex MAGPIX system. Receiver operating characteristic (ROC) analysis was performed to calculate the cutoff values of the three markers for identifying the patients with metastases. The ability to identify patients with metastases was compared between the single markers and the combination as a three-marker panel. By using the Student’s t-test, we also investigated the kinetic changes of the levels of BAFF, GDF-15 and OPN across six periods (i.e., 0–6 months, 6–12 months, 12–18 months, 18–24 months, >24 months and post-metastasis) before the imaging diagnosis of metastases. By maximizing the Youden’s index, the serum GDF-15 level of 1209 pg/mL and the plasma OPN level of 92 ng/mL were identified to have the best performance for distinguishing the metastatic patients from non-metastatic patients. The three-marker panel offered a better performance in distinguishing patients with metastases, with an area under the curve of 0.802, than any single biomarker. Increasing trends of the levels of three biomarkers were observed in the two-year period before the imaging diagnosis of metastases. The combined panel of BAFF, GDF-15 and OPN might be a utilizable implementation for the detection of UM metastases. In the bioinformatics study with two external datasets, the high expression of gene BAFF and GDF-15 in primary UM tissues was identified to be associated with poor overall survival rates. As the current work is a single-center retrospective study, more well-designed prospective investigations employing larger cohorts are urgently needed to validate our findings.

Exploring the role of BAFF as biomarker in the detection of uveal melanoma metastases

PURPOSE

While B-cell activating factor (BAFF) was identified to promote the invasion in other malignancies, its role in the progression of uveal melanoma (UM) still remains unexplored. Here, we analysed the serum level of BAFF in UM patients with regard to its significance as biomarker for the metastases.

METHODS

In this retrospective study, serum BAFF levels in 173 UM patients (36 with metastases and 137 without), and 23 healthy controls were measured with a multiplexed sandwich ELISA system and then correlated with clinicopathological characteristics such as primary tumor size, tumor location, histological cell type, sex, cancer stage, cytogenetic alterations of chromosome 3, and the metastatic burden. Immunohistochemical staining of 50 UM tissue specimens was also performed to evaluate the expression of BAFF and its receptors BAFF-R and TACI.

RESULTS

The metastatic patients were identified to have significantly higher serum BAFF levels (mean ± SD, 1520.8 ± 1182.1 pg/ml) than those without metastases (950.4 ± 494.6 pg/ml) and controls (810.3 ± 140.5 pg/ml). While no distinctions were detected with regard to tumor location, histological cell type, gender, and monosomy 3, the patients in cancer stages II, III, and IV displayed higher serum BAFF levels than those in stage I. The serum BAFF level was significantly correlated with the metastatic burden. The serum BAFF level of 1120 pg/ml was identified to have the best performance for distinguishing the metastatic patients from non-metastatic patients. In the kinetic study, we noticed that 20.8% of the analysed patients already demonstrated elevated serum BAFF concentrations before the clinical diagnosis of metastases. Positive BAFF staining was detected in the cytoplasm of single tumor cells (in 13 specimens), macrophages (in 12 specimens), and tumor-infiltrating lymphocytes (TILs) (in 13 specimens). The expressions of BAFF-R and TACI were also observed in 17 and 36 of the 50 tested UM specimens, respectively.

CONCLUSIONS

Our study first suggests that BAFF might be a promising serum marker for the detection of UM metastases.

Effects of B cell-activating factor on tumor immunity

Immunotherapies that modulate T cell function have been firmly established as a pillar of cancer therapy, whereas the potential for B cells in the antitumor immune response is less established. B cell-activating factor (BAFF) is a B cell-activating cytokine belonging to the TNF ligand family that has been associated with autoimmunity, but little is known about its effects on cancer immunity. We find that BAFF upregulates multiple B cell costimulatory molecules; augments IL-12a expression, consistent with Be-1 lineage commitment; and enhances B cell antigen-presentation to CD4+ Th cells in vitro. In a syngeneic mouse model of melanoma, BAFF upregulates B cell CD40 and PD-L1 expression; it also modulates T cell function through increased T cell activation and TH1 polarization, enhanced expression of the proinflammatory leukocyte trafficking chemokine CCR6, and promotion of a memory phenotype, leading to enhanced antitumor immunity. Similarly, adjuvant BAFF promotes a memory phenotype of T cells in vaccine-draining lymph nodes and augments the antitumor efficacy of whole cell vaccines. BAFF also has distinct immunoregulatory functions, promoting the expansion of CD4+Foxp3+ Tregs in the spleen and tumor microenvironment (TME). Human melanoma data from The Cancer Genome Atlas (TCGA) demonstrate that BAFF expression is positively associated with overall survival and a TH1/IFN-γ gene signature. These data support a potential role for BAFF signaling as a cancer immunotherapy.

MYC Instructs and Maintains Pancreatic Adenocarcinoma Phenotype

The signature features of pancreatic ductal adenocarcinoma (PDAC) are its fibroinflammatory stroma, poor immune activity, and dismal prognosis. We show that acute activation of Myc in indolent pancreatic intraepithelial neoplasm (PanIN) epithelial cells in vivo is, alone, sufficient to trigger immediate release of instructive signals that together coordinate changes in multiple stromal and immune-cell types and drive transition to pancreatic adenocarcinomas that share all the characteristic stromal features of their spontaneous human counterpart. We also demonstrate that this Myc-driven PDAC switch is completely and immediately reversible: Myc deactivation/inhibition triggers meticulous disassembly of advanced PDAC tumor and stroma and concomitant death of tumor cells. Hence, both the formation and deconstruction of the complex PDAC phenotype are continuously dependent on a single, reversible Myc switch. SIGNIFICANCE: We show that Myc activation in indolent Kras G12D-induced PanIN epithelium acts as an immediate pleiotropic switch, triggering tissue-specific signals that instruct all the diverse signature stromal features of spontaneous human PDAC. Subsequent Myc deactivation or inhibition immediately triggers a program that coordinately disassembles PDAC back to PanIN.See related commentary by English and Sears, p. 495.

ABO Blood Type and the Long-term Outcomes of Pancreatic Cancer

Objective The long-term effect of the ABO blood type on the clinical course of patients with pancreatic cancer (PC) is inconclusive. This study aimed to determine whether or not the ABO blood type influences the long-term outcomes of PC in Japanese patients. Methods The medical records of Japanese patients with PC were reviewed. Data, including the age, sex, and outcomes, from the Ehime Pancreato-Cholangiology Study Group were analyzed. Results The mean age of the 406 patients was 71.0±10.5 years, and 220 (54.2%) were men. A total of 44.6%, 20.7%, 22.4%, and 12.3% had blood type A, B, O, and AB, respectively. The median survival time (MST) of patients with A alleles was shorter than that of patients with non-A alleles (p=0.048), especially among those who underwent resection (p=0.031). In contrast, no marked difference in the MST was noted among those who underwent chemotherapy and palliative care. Finally, a multivariate analysis confirmed A alleles as an independent factor associated with the long-term outcome of PC (p<0.05 in 2 different models). Conclusion The ABO blood type influenced the long-term outcomes of Japanese patients with PC, presumably due to its impact on disease onset and tumor behavior.

Early Detection of Pancreatic Cancer in Patients With Chronic Liver Disease Under Hepatocellular Carcinoma Surveillance

OBJECTIVE

To evaluate whether patients with hepatitis B virus (HBV)- and hepatitis C virus (HCV)-related chronic liver disease were diagnosed as having pancreatic cancer (PC) at an early stage during abdominal imaging surveillance for hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

We retrospectively examined 447 patients with PC diagnosed at Ehime University Hospital and affiliated centers (2011-2013). Data were collected regarding HBV and HCV status, likelihood of PC diagnosis, and Union for International Cancer Control (UICC) stage. Intergroup comparisons were performed using the χ² test.

RESULTS

The UICC stage distribution in the HCC surveillance group (n=16) was stage 0 (n=2, 12.5%), stage IA (n=3, 18.8%), stage IB (n=2, 12.5%), stage IIA (n=2, 12.5%), stage IIB (n=2, 12.5%), stage III (n=1, 6.3%), and stage IV (n=4, 25%). The UICC stage distribution in the nonsurveillance group (n=431) was stage 0 (n=4, 0.9%), stage IA (n=28, 6.5%), stage IB (n=27, 6.3%), stage IIA (n=86, 20.0%), stage IIB (n=48, 11.1%), stage III (n=56, 13.0%), and stage IV (n=182, 42.2%). The HCC surveillance group had significantly more patients with stage 0 disease than with stages IA through IV (P=.02). Similar results were observed when including stages IA (P=.007) and IB (P=.004) as early stages but not stage IIA (P=.10). A dilated pancreatic duct led to a PC diagnosis in all 6 patients with stage 0 disease.

CONCLUSION

Patients with HBV- and HCV-related chronic liver disease had an early PC diagnosis during HCC surveillance. Careful evaluation of the pancreas is warranted during HCC surveillance.

Expression of Immune System-Related Membrane Receptors CD40, RANK, BAFFR and LTβR is Associated with Clinical Outcome of Operated Non-Small-Cell Lung Cancer Patients

An increasing number of studies implicates the NF-κB (Nuclear Factor of kappa light chain gene enhancer in B cells) alternative pathway in non-small-cell lung cancer (NSCLC). We assessed the clinical significance of CD40 (Tumor necrosis factor receptor superfamily member 5, TNFRSF5), BAFFR (B-cell activating factor receptor), RANK (Receptor activator of NF-κB) and LTβR (lymphotoxin β receptor) receptors, which activate the alternative pathway of NF-κB, in NSCLC. Evaluation of CD40, BAFFR, RANK and LTβR expression was performed based on the Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) datasets, while protein expression was assessed by immunohistochemistry in specimens from 119 operated NSCLC patients. CD40 gene overexpression was correlated with improved five-year overall survival (OS) (p < 0.001), while increased BAFFR and LTβR mRNA levels were associated with worse OS in patients with adenocarcinomas (p < 0.001 and p < 0.001, respectively). Similarly, patients with adenocarcinomas exhibited a negative correlation between membranous BAFFR protein expression in carcinoma cells and three- and five-year survival (p = 0.021; HR, 4.977 and p = 0.030; HR, 3.358, respectively) as well as between BAFFR protein overexpression in cancer-associated fibroblasts (CAFs) and two-year survival (p = 0.036; HR, 1.983). Patients with increased LTβR nuclear protein staining or stage II patients with lower cytoplasmic LTβR protein expression had worse five-year OS (p = 0.039 and p = 0.008, respectively). Moreover, CD40 protein expression in tumor infiltrating lymphocytes (TILs) and CAFs was positively associated with metastatic spread while BAFFR protein expression in CAFs was negatively associated with bone metastasis (p = 0.041). Our data suggests that CD40, BAFFR, RANK and LTβR play an important role in NSCLC and further supports the role of NF-κB alternative pathway in NSCLC.

The Vicious Cross-Talk between Tumor Cells with an EMT Phenotype and Cells of the Immune System

Carcinoma cells that undergo an epithelial-mesenchymal transition (EMT) and display a predominantly mesenchymal phenotype (hereafter EMT tumor cells) are associated with immune exclusion and immune deviation in the tumor microenvironment (TME). A large body of evidence has shown that EMT tumor cells and immune cells can reciprocally influence each other, with EMT cells promoting immune exclusion and deviation and immune cells promoting, under certain circumstances, the induction of EMT in tumor cells. This cross-talk between EMT tumor cells and immune cells can occur both between EMT tumor cells and cells of either the native or adaptive immune system. In this article, we review this evidence and the functional consequences of it. We also discuss some recent evidence showing that tumor cells and cells of the immune system respond to similar stimuli, activate the expression of partially overlapping gene sets, and acquire, at least in part, identical functionalities such as migration and invasion. The possible significance of these symmetrical changes in the cross-talk between EMT tumor cells and immune cells is addressed. Eventually, we also discuss possible therapeutic opportunities that may derive from disrupting this cross-talk.

B cell activation factor (BAFF) induces inflammation in the human fallopian tube leading to tubal pregnancy

Background

Tubal pregnancy is recognized as one of the most common ectopic pregnancy types. Salpingitis may result in tubal pregnancy by causing fallopian tube occlusion and hydrosalpinx. B cell activation factor (BAFF) is a proinflammatory cytokine that helps regulate both innate and adaptive immune responses. Our previous study firstly showed that BAFF immunostaining appeared on the cellular membrane and in the cytoplasm of tubal epithelial cells, and both BAFF protein and mRNA in human inflamed fallopian tubes had higher expression levels than those in normal fallopian tubes. This study aimed to elucidate the association between the expression of BAFF gene and the inflammation in the human fallopian tube leading to tubal pregnancy.

Methods

We examined 70 patients undergoing salpingectomy for salpingitis (n = 35) and tubal pregnancy (n = 35). Twenty patients with benign uterine diseases undergoing complete hysterectomy and salpingectomy were recruited into control group. BAFF mRNA and protein in tissue samples were detected by qPCR and Western blotting methods. Furthermore, serum levels of BAFF, tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were measured using ELISA kits.

Results

We found statistically significantly elevated expressions of BAFF mRNA or protein in whole tissue samples, and serum levels of BAFF, TNF-α and IL-6 in whole blood samples from patients with salpingitis and tubal pregnancy, in comparison to the control group.

Conclusion

Based on the results, high expression of BAFF gene might induce inflammation in the human fallopian tube, suggesting its possible role in the tubal pregnancy process.

Hypoxia as a barrier to immunotherapy in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease with limited response to cytotoxic chemoradiotherapy, as well as newer immunotherapies. The PDA tumor microenvironment contains infiltrating immune cells including cytotoxic T cells; however, there is an overall immunosuppressive milieu. Hypoxia is a known element of the solid tumor microenvironment and may promote tumor survival. Through various mechanisms including, but not limited to, those mediated by HIF-1α, hypoxia also leads to increased tumor proliferation and metabolic changes. Furthermore, epithelial to mesenchymal transition is promoted through several pathways, including NOTCH and c-MET, regulated by hypoxia. Hypoxia-promoted changes also contribute to the immunosuppressive phenotype seen in many different cell types within the microenvironment and thereby may inhibit an effective immune system response to PDA. Pancreatic stellate cells (PSCs) and myofibroblasts appear to contribute to the recruitment of myeloid derived suppressor cells (MDSCs) and B cells in PDA via cytokines increased due to hypoxia. PSCs also increase collagen secretion in response to HIF-1α, which promotes a fibrotic stroma that alters T cell homing and migration. In hypoxic environments, B cells contribute to cytotoxic T cell exhaustion and produce chemokines to attract more immunosuppressive regulatory T cells. MDSCs inhibit T cell metabolism by hoarding key amino acids, modulate T cell homing by cleaving L-selectin, and prevent T cell activation by increasing PD-L1 expression. Immunosuppressive M2 phenotype macrophages promote T cell anergy via increased nitric oxide (NO) and decreased arginine in hypoxia. Increased numbers of regulatory T cells are seen in hypoxia which prevent effector T cell activation through cytokine production and increased CTLA-4. Effective immunotherapy for pancreatic adenocarcinoma and other solid tumors will need to help counteract the immunosuppressive nature of hypoxia-induced changes in the tumor microenvironment. Promising studies will look at combination therapies involving checkpoint inhibitors, chemokine inhibitors, and possible targeting of hypoxia. While no model is perfect, assuring that models incorporate the effects of hypoxia on cancer cells, stromal cells, and effector immune cells will be crucial in developing successful therapies.

Functions of the CXC ligand family in the pancreatic tumor microenvironment

Therapeutic resistance is the major contributor to the poor prognosis of and low survival from pancreatic cancer (PC). Cancer progression is a complex process reliant on interactions between the tumor and the tumor microenvironment (TME). Members of the CXCL family of chemokines are present in the pancreatic TME and seem to play a vital role in regulating PC progression. As pancreatic tumors interact with the TME and with PC stem cells (CSCs), determining the roles of specific members of the CXCL family is vital to the development of improved therapies. This review highlights the roles of selected CXCLs in the interactions between pancreatic tumor and its stroma, and in CSC phenotypes, which can be used to identify potential treatment targets.

Kras and Tumor Immunity: Friend or Foe?

With the recent breakthroughs in immunotherapy as curative treatments in certain tumor types, there has been renewed interest in the relationship between immunity and tumor growth. Although we are gaining a greater understanding of the complex interplay of immune modulating components in the tumor microenvironment, the specific role that tumor cells play in shaping the immune milieu is still not well characterized. In this review, we focus on how mutant Kras tumor cells contribute to tumor immunity, with a specific focus on processes induced directly or indirectly by the oncogene.

Characteristics of functional enrichment and gene expression level of human putative transcriptional target genes

BACKGROUND

Transcriptional target genes show functional enrichment of genes. However, how many and how significantly transcriptional target genes include functional enrichments are still unclear. To address these issues, I predicted human transcriptional target genes using open chromatin regions, ChIP-seq data and DNA binding sequences of transcription factors in databases, and examined functional enrichment and gene expression level of putative transcriptional target genes.

RESULTS

Gene Ontology annotations showed four times larger numbers of functional enrichments in putative transcriptional target genes than gene expression information alone, independent of transcriptional target genes. To compare the number of functional enrichments of putative transcriptional target genes between cells or search conditions, I normalized the number of functional enrichment by calculating its ratios in the total number of transcriptional target genes. With this analysis, native putative transcriptional target genes showed the largest normalized number of functional enrichments, compared with target genes including 5-60% of randomly selected genes. The normalized number of functional enrichments was changed according to the criteria of enhancer-promoter interactions such as distance from transcriptional start sites and orientation of CTCF-binding sites. Forward-reverse orientation of CTCF-binding sites showed significantly higher normalized number of functional enrichments than the other orientations. Journal papers showed that the top five frequent functional enrichments were related to the cellular functions in the three cell types. The median expression level of transcriptional target genes changed according to the criteria of enhancer-promoter assignments (i.e. interactions) and was correlated with the changes of the normalized number of functional enrichments of transcriptional target genes.

CONCLUSIONS

Human putative transcriptional target genes showed significant functional enrichments. Functional enrichments were related to the cellular functions. The normalized number of functional enrichments of human putative transcriptional target genes changed according to the criteria of enhancer-promoter assignments and correlated with the median expression level of the target genes. These analyses and characters of human putative transcriptional target genes would be useful to examine the criteria of enhancer-promoter assignments and to predict the novel mechanisms and factors such as DNA binding proteins and DNA sequences of enhancer-promoter interactions.

Targeting Pancreatic Cancer Cell Plasticity: The Latest in Therapeutics

Mortality remains alarmingly high for patients diagnosed with pancreatic ductal adenocarcinoma (PDAC), with 93% succumbing to the disease within five years. The vast majority of PDAC cases are driven by activating mutations in the proto-oncogene KRAS, which results in constitutive proliferation and survival signaling. As efforts to target RAS and its downstream effectors continue, parallel research aimed at identifying novel targets is also needed in order to improve therapeutic options and efficacy. Recent studies demonstrate that self-renewing cancer stem cells (CSCs) contribute to metastatic dissemination and therapy failure, the causes of mortality from PDAC. Here, we discuss current challenges in PDAC therapeutics, highlight the contribution of mesenchymal/CSC plasticity to PDAC pathogenesis, and propose that targeting the drivers of plasticity will prove beneficial. Increasingly, intrinsic oncogenic and extrinsic pro-growth/survival signaling emanating from the tumor microenvironment (TME) are being implicated in the de novo generation of CSC and regulation of tumor cell plasticity. An improved understanding of key regulators of PDAC plasticity is providing new potential avenues for targeting the properties associated with CSC (including enhanced invasion and migration, metastatic outgrowth, and resistance to therapy). Finally, we describe the growing field of therapeutics directed at cancer stem cells and cancer cell plasticity in order to improve the lives of patients with PDAC.

Role of immune cells in pancreatic cancer from bench to clinical application: An updated review

BACKGROUND

Pancreatic cancer (PC) remains difficult to treat, despite the recent advances in various anticancer therapies. Immuno-inflammatory response is considered to be a major risk factor for the development of PC in addition to a combination of genetic background and environmental factors. Although patients with PC exhibit evidence of systemic immune dysfunction, the PC microenvironment is replete with immune cells.

METHODS

We searched PubMed for all relevant English language articles published up to March 2016. They included clinical trials, experimental studies, observational studies, and reviews. Trials enrolled at Clinical trial.gov were also searched.

RESULTS

PC induces an immunosuppressive microenvironment, and intratumoral activation of immunity in PC is attenuated by inhibitory signals that limit immune effector function. Multiple types of immune responses can promote an immunosuppressive microenvironment; key regulators of the host tumor immune response are dendritic cells, natural killer cells, macrophages, myeloid derived suppressor cells, and T cells. The function of these immune cells in PC is also influenced by chemotherapeutic agents and the components in tumor microenvironment such as pancreatic stellate cells. Immunotherapy of PC employs monoclonal antibodies/effector cells generated in vitro or vaccination to stimulate antitumor response. Immune therapy in PC has failed to improve overall survival; however, combination therapies comprising immune checkpoint inhibitors and vaccines have been attempted to increase the response.

CONCLUSION

A number of studies have begun to elucidate the roles of immune cell subtypes and their capacity to function or dysfunction in the tumor microenvironment of PC. It will not be long before immune therapy for PC becomes a clinical reality.

CRISPR-Mediated VHL Knockout Generates an Improved Model for Metastatic Renal Cell Carcinoma

Metastatic renal cell carcinoma (mRCC) is nearly incurable and accounts for most of the mortality associated with RCC. Von Hippel Lindau (VHL) is a tumour suppressor that is lost in the majority of clear cell RCC (ccRCC) cases. Its role in regulating hypoxia-inducible factors-1α (HIF-1α) and -2α (HIF-2α) is well-studied. Recent work has demonstrated that VHL knock down induces an epithelial-mesenchymal transition (EMT) phenotype. In this study we showed that a CRISPR/Cas9-mediated knock out of VHL in the RENCA model leads to morphologic and molecular changes indicative of EMT, which in turn drives increased metastasis to the lungs. RENCA cells deficient in HIF-1α failed to undergo EMT changes upon VHL knockout. RNA-seq revealed several HIF-1α-regulated genes that are upregulated in our VHL knockout cells and whose overexpression signifies an aggressive form of ccRCC in the cancer genome atlas (TCGA) database. Independent validation in a new clinical dataset confirms the upregulation of these genes in ccRCC samples compared to adjacent normal tissue. Our findings indicate that loss of VHL could be driving tumour cell dissemination through stabilization of HIF-1α in RCC. A better understanding of the mechanisms involved in this phenomenon can guide the search for more effective treatments to combat mRCC.

IL35-Producing B Cells Promote the Development of Pancreatic Neoplasia

A salient feature of pancreatic ductal adenocarcinoma (PDAC) is an abundant fibroinflammatory response characterized by the recruitment of immune and mesenchymal cells and the consequent establishment of a protumorigenic microenvironment. Here, we report the prominent presence of B cells in human pancreatic intraepithelial neoplasia and PDAC lesions as well as in oncogenic Kras-driven pancreatic neoplasms in the mouse. The growth of orthotopic pancreatic neoplasms harboring oncogenic Kras was significantly compromised in B-cell-deficient mice (μMT), and this growth deficiency could be rescued by the reconstitution of a CD1d(hi)CD5(+) B-cell subset. The protumorigenic effect of B cells was mediated by their expression of IL35 through a mechanism involving IL35-mediated stimulation of tumor cell proliferation. Our results identify a previously unrecognized role for IL35-producing CD1d(hi)CD5(+) B cells in the pathogenesis of pancreatic cancer and underscore the potential significance of a B-cell/IL35 axis as a therapeutic target.

SIGNIFICANCE

This study identifies a B-cell subpopulation that accumulates in the pancreatic parenchyma during early neoplasia and is required to support tumor cell growth. Our findings provide a rationale for exploring B-cell-based targeting approaches for the treatment of pancreatic cancer.

B-Cell Activating Factor as a Cancer Biomarker and Its Implications in Cancer-Related Cachexia

B-cell activating factor (BAFF) is a cytokine and adipokine of the TNF ligand superfamily. The main biological function of BAFF in maintaining the maturation of B-cells to plasma cells has recently made it a target of the first FDA-approved selective BAFF antibody, belimumab, for the therapy of systemic lupus erythematosus. Concomitantly, the role of BAFF in cancer has been a subject of research since its discovery. Here we review BAFF as a biomarker of malignant disease activity and prognostic factor in B-cell derived malignancies such as multiple myeloma. Moreover, anti-BAFF therapy seems to be a promising approach in treatment of B-cell derived leukemias/lymphomas. In nonhematologic solid tumors, BAFF may contribute to cancer progression by mechanisms both dependent on and independent of BAFF's proinflammatory role. We also describe ongoing research into the pathophysiological link between BAFF and cancer-related cachexia. BAFF has been shown to contribute to inflammation and insulin resistance which are known to worsen cancer cachexia syndrome. Taking all the above together, BAFF is emerging as a biomarker of several malignancies and a possible hallmark of cancer cachexia.

Complex role for the immune system in initiation and progression of pancreatic cancer

The immune system plays a complex role in the development and progression of pancreatic cancer. Inflammation can promote the formation of premalignant lesions and accelerate pancreatic cancer development. Conversely, pancreatic cancer is characterized by an immunosuppressive environment, which is thought to promote tumor progression and invasion. Here we review the current literature describing the role of the immune response in the progressive development of pancreatic cancer, with a focus on the mechanisms that drive recruitment and activation of immune cells at the tumor site, and our current understanding of the function of the immune cell types at the tumor. Recent clinical and preclinical data are reviewed, detailing the involvement of the immune response in pancreatitis and pancreatic cancer, including the role of specific cytokines and implications for disease outcome. Acute pancreatitis is characterized by a predominantly innate immune response, while chronic pancreatitis elicits an immune response that involves both innate and adaptive immune cells, and often results in profound systemic immune-suppression. Pancreatic adenocarcinoma is characterized by marked immune dysfunction driven by immunosuppressive cell types, tumor-promoting immune cells, and defective or absent inflammatory cells. Recent studies reveal that immune cells interact with cancer stem cells and tumor stromal cells, and these interactions have an impact on development and progression of pancreatic ductal adenocarcinoma (PDAC). Finally, current PDAC therapies are reviewed and the potential for harnessing the actions of the immune response to assist in targeting pancreatic cancer using immunotherapy is discussed.

Manipulation of tumour-infiltrating B cells and tertiary lymphoid structures: a novel anti-cancer treatment avenue?

Combining different standard therapies with immunotherapy for the treatment of solid tumours has proven to yield a greater clinical benefit than when each is applied separately; however, the percentage of complete responses is still far from optimal, and there is an urgent need for improved treatment modalities. The latest literature data suggest that tertiary lymphoid structures (TLS), previously shown to correlate with the severity of autoimmune diseases or transplant rejection, are also formed in tumours, have a significant beneficial effect on survival and might reflect the generation of an effective immune response in close proximity to the tumour. Thus, the facilitation of TLS formation in tumour stroma could provide novel means to improve the efficiency of immunotherapy and other standard therapies. However, little is known about the mechanisms regulating the formation of tumour-associated TLS. Studies of chronic inflammatory diseases and transplant rejection have demonstrated that TLS formation and/or function requires the presence of B cells. Additionally, the infiltration of B cells into the tumour stroma has been demonstrated to be a significant prognostic factor for improved survival in different human tumours. This suggests that B cells could play a beneficial role in anti-tumour immune response not only in the context of antibody production, antigen presentation and Th1-promoting cytokine production, but also TLS formation. This review focuses on the latest discoveries in tumour-infiltrating B cell functions, their role in TLS formation and relevance in human tumour control, revealing novel opportunities to improve cancer therapies.

Serum levels of B-cell activating factor in chronic hepatitis B virus infection: association with clinical diseases

B-lymphocyte activation is a common characteristic of chronic hepatitis B virus (HBV) infection. B cell-activating factor (BAFF) plays a crucial role in the development and activation of B lymphocytes. This study investigated serum BAFF levels in 232 patients with different clinical diseases of chronic HBV infection [33 chronic asymptomatic HBV carrier (ASC), 53 chronic hepatitis (CH), 72 liver cirrhosis (LC), and 74 hepatocellular carcinoma (HCC)] and 61 gender- and age-matched healthy controls. Serum BAFF levels in HBV patients were significantly elevated compared with healthy controls (P<0.001). HCC patients had significantly higher levels of serum BAFF than ASC, CH, and LC (all P<0.001). Serum levels of BAFF in LC were significantly higher than in ASC (P<0.001) and CH (P=0.002). Serum level of BAFF was an independent variable associated with the presence of HCC in comparison with other disease groups in multivariate analysis. The area under receiver-operating characteristic curve (AUC) value of BAFF levels was 0.914 for HCC versus ASC, 0.825 for HCC versus CH, and 0.607 for HCC versus LC, respectively. The AUC value of BAFF levels was 0.854 for LC versus ASC and 0.748 for LC versus CH, respectively. The AUC value of BAFF (0.888) for HCC was higher than that of alpha-fetoprotein (0.776). We first demonstrate that serum BAFF levels in chronic HBV infection are elevated, correlated with clinical diseases, and could be used as a biomarker for indicating disease mechanisms, activity, and diagnosis.