Pro-inflammatory effects of the Th1 chemokine CXCL10 in acquired aplastic anaemia

High serum C-X-C motif chemokine ligand 10 (CXCL10) levels may be associated with new onset interstitial lung disease in patients with systemic sclerosis: evidence from observational, clinical, transcriptomic and in vitro studies

BACKGROUND

Systemic sclerosis-interstitial lung disease (SSc-ILD) is the leading cause of death in patients with SSc. There is an unmet need for predictive biomarkers to identify patients with SSc at risk of ILD. Previous studies have shown that interferon (IFN) pathways may play a role in SSc. We assessed the use of C-X-C motif chemokine ligand 10 (CXCL10) as a predictive biomarker for new onset of ILD in patients with SSc.

METHODS

One-hundred-sixty-five (Female, N = 130) patients with SSc (SSc-ILD, N = 41) and 13 (Female, N = 8) healthy controls were investigated retrospectively. CXCL10 protein levels were measured by ELISA. We performed log rank analysis with baseline CXCL10 serum levels. CXCL10 nanoString data from lung tissues obtained from transplanted patients with SSc-ILD were extracted. Fifteen (Female, N = 10) patients with SSc (SSc-ILD, N = 7) were recruited for bronchoalveolar lavage (BAL) procedure. Lung fibroblasts were treated with BAL-fluid or serum from patients with SSc with or without ILD. Inflammatory/fibrotic genes were assessed.

FINDINGS

Serum CXCL10 levels were higher in patients with SSc-ILD compared to SSc patients without ILD [Median (IQR):126 pg/ml (66-282.5) vs. 78.5 pg/ml (50-122), P = 0.029, 95% CI: 1.5 × 10-6 to 0.4284]. Survival analysis showed that baseline CXCL10 levels >78.5 pg/ml have a 2.74-fold increased risk of developing new onset of ILD (Log-rank: P = 0.119) on follow-up. CXCL10 levels in BAL supernatant were not different in patients with SSc-ILD compared to SSc without ILD [76.1 pg/ml (7.2-120.8) vs. 22.3 pg/ml (12.1-43.7), P = 0.24, 95% CI: -19.5 to 100]. NanoString showed that CXCL10 mRNA expression was higher in inflammatory compared to fibrotic lung tissues [4.7 (4.2-5.6) vs. 4.3 (3.6-4.7), P = 0.029]. Fibroblasts treated with SSc-ILD serum or BAL fluids overexpressed CXCL10.

INTERPRETATIONS

Clinical, transcriptomic, and in vitro data showed that CXCL10 is potentially involved in early SSc-ILD. More research is needed to confirm whether CXCL10 can be classified as a prospective biomarker to detect patients with SSc at higher risk of developing new onset ILD.

FUNDING

This collaborative project is co-financed by the Ministry of Economic Affairs and Climate Policy of the Netherlands utilizing the PPP-allowance made available by the Top Sector Life Sciences & Health to stimulate public-private partnerships (PPP-2019_007). Part of this study is financially supported by Sanofi Genzyme (NL8921).

A candidate nanoparticle vaccine comprised of multiple epitopes of the African swine fever virus elicits a robust immune response

The African swine fever (ASF) pandemics pose a significant threat to the global swine industry, and the development of safe and effective vaccines is a daunting but necessary challenge. The level and persistence of immunity are very important for the effectiveness of the vaccine. Targeting antigens to antigen presenting cells (APCs) can greatly enhance immunogenicity. In this study, we developed a self-assembled nano-ASFV vaccine candidate (NanoFVax) targeting DCs, by covalently coupling the self-assembled 24-mer ferritin with the dominant B and T cell epitopes of the highly immunogenic ASFV antigen (p72, CD2v, pB602L and p30) and fused with the chemokine receptor XCL1 (a DC targeting molecule) through the SpyTag/SpyCatcher protein ligase system. Compared to monomeric protein, the nanoparticle vaccines can induce a more robust T-cell response, and the high-level antibody response against ASFV can last for more than 231 days. Therefore, the NanoFVax is a novel and promising vaccine candidate for ASFV.

Release of High-Mobility Group Box-1 after a Raynaud's Attack Leads to Fibroblast Activation and Interferon-γ Induced Protein-10 Production: Role in Systemic Sclerosis Pathogenesis

Raynaud's Phenomenon (RP) leading to repetitive ischemia and reperfusion (IR) stress, is the first recognizable sign of systemic sclerosis (SSc) leading to increased oxidative stress. High-mobility group box-1 (HMGB1) is a nuclear factor released by apoptotic and necrotic cells after oxidative stress. Since HMGB1 can signal through the receptor for advanced glycation end products (RAGE), we investigated whether an RP attack promotes the release of HMGB1, leading to fibroblast activation and the upregulation of interferon (IFN)-inducible genes. A cold challenge was performed to simulate an RP attack in patients with SSc, primary RP (PRP), and healthy controls. We measured levels of HMGB1 and IFN gamma-induced Protein 10 (IP-10) at different time points in the serum. Digital perfusion was assessed by photoplethysmography. In vitro, HMGB1 or transforming growth factor (TGF-β1) (as control) was used to stimulate healthy human dermal fibroblasts. Inflammatory, profibrotic, and IFN-inducible genes, were measured by RT-qPCR. In an independent cohort, sera were obtained from 20 patients with SSc and 20 age- and sex-matched healthy controls to determine HMGB1 and IP-10 levels. We found that HMGB1 levels increased significantly 30 min after the cold challenge in SSc compared to healthy controls. In vitro stimulation with HMGB1 resulted in increased mRNA expression of IP-10, and interleukin-6 (IL-6) while TGF-β1 stimulation promoted IL-6 and Connective Tissue Growth Factor (CTGF). In serum, both HMGB1 and IP-10 levels were significantly higher in patients with SSc compared to healthy controls. We show that cold challenge leads to the release of HMGB1 in SSc patients. HMGB1 induces IP-10 expression in dermal fibroblasts partly through the soluble RAGE (sRAGE) axis suggesting a link between RP attacks, the release of HMGB1 and IFN-induced proteins as a putative early pathogenetic mechanism in SSc.

Association between severe anaemia and inflammation, risk of IRIS and death in persons with HIV: A multinational cohort study

BACKGROUND

After initiating antiretroviral therapy (ART), approximately 25% of people with HIV (PWH) may develop Immune Reconstitution Inflammatory Syndrome (IRIS), which is associated with increased morbidity and mortality. Several reports have demonstrated that low haemoglobin (Hb) levels are a risk factor for IRIS. To what extent the severity of anaemia contributes to the risk of IRIS and/or death is still insufficiently explored.

METHODS

We investigated both the presence and severity of anaemia in PWH in a multinational cohort of ART-naïve patients. A large panel of plasma biomarkers was measured pre-ART and patients were followed up for 6 months. IRIS or deaths during this period were considered as outcomes. We performed multidimensional analyses, logistic regression, and survival curves to delineate associations.

FINDINGS

Patients with severe anaemia (SA) presented a distinct systemic inflammatory profile, characterized by higher TNF, IL-6, and IL-27 levels. SA was independently associated with IRIS, with a higher risk of both early IRIS onset and death. Among IRIS patients, those with SA had a higher risk of mycobacterial IRIS.

INTERPRETATION

PWH with SA display a more pronounced inflammatory profile, with an elevated risk of developing IRIS earlier and a statistically significant higher risk of death.

FUNDING

Intramural Research Program of National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH). Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Finance code: 001) and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil.

The cytokine profiles in follicular fluid and reproductive outcomes in women with endometriosis

PROBLEM

Endometriosis patients undergoing in vitro fertilization-embryo transfer (IVF-ET) treatment suffer from poor oocyte quality, a reduced likelihood of the fertilization rate, and low embryo quality. The dysregulation of immune cells and cytokine profiles in the follicular fluid (FF) may play an important role in the competence of the oocyte and the development of the embryo, but the mechanism remains largely unknown.

METHOD OF STUDY

A total of 40 proved advanced staged endometriosis patients were enrolled in this study. The pregnancy results were followed until all the embryos collected by the first oocyte retrieval cycle were used up. The immune cells subtypes in FF and serum collected on the day of oocyte retrieval were detected by flow cytometry and 27 cytokines were determined using the Bio-Plex Pro Human Cytokine 27-Plex Immunoassay. The specific effect of cytokine on the gene expression of human granulosa cells was determined by RT-qPCR.

RESULTS

The fertilization rate and the cumulative live birth rate were significantly lower in the endometriosis group. The ratio of CD4⁺ /CD8⁺ T cells in FF was significantly lower, while the level of IP-10, RANTES and G-CSF were statistically higher in the endometriosis group. The level of IP-10 correlated with the IVF outcome. Moreover, treated by IP-10, the mRNA level of FSHR and CYP19A1 the human granulosa cells were downregulated in vitro.

CONCLUSION

These results suggest that alterations of the lymphocyte subsets and cytokines in women with advanced endometriosis may have an impact on the oocyte development and resulting in poorer IVF outcomes.

Leptin-mediated proinflammatory bone marrow environment in acquired aplastic anemia

Acquired aplastic anemia (AA), a paradigm of bone marrow failure syndrome, is mainly caused by abnormal immune activation. The enhanced adipogenesis of bone marrow-derived mesenchymal stem cell (BM-MSC) results in a fatty marrow of AA. Leptin, an adipokine mainly generated by adipocytes, has powerful proinflammatory effects on immune cells and is associated with various autoimmune diseases. However, the role of leptin in the hyperimmune status of AA remains unknown. In this study, we firstly discovered the higher leptin concentration in AA-BM than that in healthy donors (HD)-BM and myelodysplastic syndrome (MDS)-BM. Then, we found AA-MSC could express high amounts of leptin during the process of adipogenesis. Compared with HD, the leptin receptor was also highly expressed on T cells in AA-BM. Furthermore, leptin significantly accelerated the proliferation and activation of T cells in AA-BM. And, leptin promoted the production of interferon-γby T cells in AA-BM. However, leptin remarkably inhibited the conversion of CD4⁺CD25^- T cells into CD4⁺Foxp3⁺ T cells. Finally, we detected the cell signaling pathway in T cells from AA patients and found leptin could activate the STAT3 pathway. In summary, our data revealed the high expression of adipokine leptin in AA-BM which shaped a proinflammatory environment for T cells in AA-BM by activating the JAK2/STAT3 pathway.

The role of IP-10 and its receptor CXCR3 in early pregnancy

The local immune microenvironment of the uterus plays an important role in a successful pregnancy. IP-10 (CXCL10) has been extensively studied in many immune-related diseases. However, the immune role of IP-10 in early pregnancy has not been fully recognized. This study mainly investigated the role of pro-inflammatory chemokine IP-10 in pregnancy. The levels of IP-10 and its receptor chemokine receptor 3 (CXCR3) were lower in the decidual tissues of an abortion-prone mice than in normal pregnant mice. Meantime, the expression of IP-10 and CXCR3 was higher in the decidual tissues of early pregnant women than in the endometrial tissues of non-pregnant women. IP-10 promoted the production of interleukin 17 (IL-17) and interferon gamma (IFN-γ), and also promoted the migration and differentiation of uterine decidual T cells to type 1 T helper (Th1) cells and Th17 cells. The abortion rate of early pregnant mice increased but the number of CD49b+, CD11b+, and CD3ε+ cells in the decidual tissues decreased upon treatment with anti-IP-10 antibody. Moreover, anti IP-10 antibody decreased the expression of RANTES but increased the expression of anti-inflammatory cytokines IL-6 and IL-10. A successful pregnancy requires the participation of IP-10. IP-10 participates in formation of the pro-inflammatory immune microenvironment during early pregnancy by regulating the distribution of immune cells and promoting the production of pro-inflammatory cytokines.

Aplastic anemia, cellular and molecular aspects

Aplastic anemia (AA) is an autoimmune disorder characterized by bone marrow and peripheral blood pancytopenia. Different environmental and genetical conditions could be effective in an outbreak of this disease. The exact pathogenesis of this disease, however, is still idiopathic. The present study is based on Pubmed database information (2002-2021) using the words "Aplastic Anemia," "Hematopoietic Stem Cells niche," "Signaling pathway," "Cytokines," and "Immuno cells." In this disease, both hematopoietic stem cells and mesenchymal stromal cells are impaired, which is associated with impaired hematopoiesis and decreased hematopoietic cells. Inflammatory cytokines increase, which changes the ratio of T lymphocytes and leads to disease progression. In addition, the most common mechanism of AA is damage by the immune system, which leads to increased apoptosis in progenitor cells. We have shown in this review that the disease involves quantitative defects in stem cell numbers and qualitative abnormalities in the function of these cells and the activity of many different cellular and molecular factors can damage hematopoietic cells and the protective substrate of these cells in this disease.

Single-cell transcriptomic analysis of allergen-specific T cells in allergy and asthma

CD4⁺ T helper (T_H) cells and regulatory T (T_reg) cells that respond to common allergens play an important role in driving and dampening airway inflammation in patients with asthma. Until recently, direct, unbiased molecular analysis of allergen-reactive T_H and T_reg cells has not been possible. To better understand the diversity of these T cell subsets in allergy and asthma, we analyzed the single-cell transcriptome of ~50,000 house dust mite (HDM) allergen-reactive T_H cells and T_reg cells from asthmatics with HDM allergy and from three control groups: asthmatics without HDM allergy and nonasthmatics with and without HDM allergy. Our analyses show that HDM allergen-reactive T_H and T_reg cells are highly heterogeneous and certain subsets are quantitatively and qualitatively different in individuals with HDM-reactive asthma. The number of interleukin-9 (IL-9)-expressing HDM-reactive T_H cells is greater in asthmatics with HDM allergy compared with nonasthmatics with HDM allergy, and this IL-9-expressing T_H subset displays enhanced pathogenic properties. More HDM-reactive T_H and T_reg cells expressing the interferon response signature (T_HIFNR and T_regIFNR) are present in asthmatics without HDM allergy compared with those with HDM allergy. In cells from these subsets (T_HIFNR and T_regIFNR), expression of TNFSF10 was enriched; its product, tumor necrosis factor-related apoptosis-inducing ligand, dampens activation of T_H cells. These findings suggest that the T_HIFNR and T_regIFNR subsets may dampen allergic responses, which may help explain why only some people develop T_H2 responses to nearly ubiquitous allergens.

Bone Marrow Failure Syndromes, Overlapping Diseases with a Common Cytokine Signature

Bone marrow failure (BMF) syndromes are a heterogenous group of non-malignant hematologic diseases characterized by single- or multi-lineage cytopenia(s) with either inherited or acquired pathogenesis. Aberrant T or B cells or innate immune responses are variously involved in the pathophysiology of BMF, and hematological improvement after standard immunosuppressive or anti-complement therapies is the main indirect evidence of the central role of the immune system in BMF development. As part of this immune derangement, pro-inflammatory cytokines play an important role in shaping the immune responses and in sustaining inflammation during marrow failure. In this review, we summarize current knowledge of cytokine signatures in BMF syndromes.

Entry and exit of chemotherapeutically-promoted cellular dormancy in glioblastoma cells is differentially affected by the chemokines CXCL12, CXCL16, and CX3CL1

Glioblastoma multiforme (GBM) is a malignant brain tumor that evades therapy regimens. Since cellular dormancy is one strategy for surviving, and since chemokines determine the environmental conditions in which dormancy occurs, we investigated how chemokines affect temozolomide (TMZ)-promoted cellular dormancy entry and exit in GBM cells. TMZ administration over ten days promoted cellular dormancy entry, whereas discontinuing TMZ for a further 15 days resulted in resumption of proliferation. Co-administration of a chemokine cocktail containing CXCL12, CXCL16, and CX3CL1 resulted in both delayed entry and exit from cellular dormancy. A microarray-based transcriptome analysis in LN229 GBM cells revealed that cellular dormancy entry was characterized by an increased expression of CCL2 and SAA2, while THSD4, FSTL3, and VEGFC were upregulated during dormancy exit. Co-stimulation with the chemokine cocktail reduced upregulation of identified genes. After verifying the appearance of identified genes in human GBM primary cultures and ex vivo samples, we clarified whether each chemokine alone impacts cellular dormancy mechanisms using specific antagonists and selective CRISPR/Cas9 clones. While expression of CCL2 and SAA2 in LN229 cells was altered by the CXCL12-CXCR4-CXCR7 axis, CXCL16 and CX3CL1 contributed to reduced upregulation of THSD4 and, to a weaker extent, of VEGFC. The influence on FSTL3 expression depended on the entire chemokine cocktail. Effects of chemokines on dormancy entry and exit-associated genes were detectable in human GBM primary cells, too, even if in a more complex, cell-specific manner. Thus, chemokines play a significant role in the regulation of TMZ-promoted cellular dormancy in GBMs.

TERC promotes cellular inflammatory response independent of telomerase

TERC is an RNA component of telomerase. However, TERC is also ubiquitously expressed in most human terminally differentiated cells, which don't have telomerase activity. The function of TERC in these cells is largely unknown. Here, we report that TERC enhances the expression and secretion of inflammatory cytokines by stimulating NK-κB pathway in a telomerase-independent manner. The ectopic expression of TERC in telomerase-negative cells alters the expression of 431 genes with high enrichment of those involved in cellular immunity. We perform genome-wide screening using a previously identified 'binding motif' of TERC and identify 14 genes that are transcriptionally regulated by TERC. Among them, four genes (LIN37, TPRG1L, TYROBP and USP16) are demonstrated to stimulate the activation of NK-κB pathway. Mechanistically, TERC associates with the promoter of these genes through forming RNA-DNA triplexes, thereby enhancing their transcription. In vivo, expression levels of TERC and TERC target genes (TYROBP, TPRG1L and USP16) are upregulated in patients with inflammation-related diseases such as type II diabetes and multiple sclerosis. Collectively, these results reveal an unknown function of TERC on stimulating inflammatory response and highlight a new mechanism by which TERC modulates gene transcription. TERC may be a new target for the development of anti-inflammation therapeutics.

The cGAS Paradox: Contrasting Roles for cGAS-STING Pathway in Chromosomal Instability

Chromosomal instability (CIN) is an intricate phenomenon that is often found in human cancer, characterized by persisting errors in chromosome segregation. This ongoing chromosome mis-segregation results in structural and numerical chromosomal abnormalities that have been widely described to promote tumor evolution. In addition to being a driver of tumor evolution, recent evidence demonstrates CIN to be the central node of the crosstalk between a tumor and its surrounding microenvironment, as mediated by the cGAS-STING pathway. The role that cGAS-STING signaling exerts on CIN tumors is both complex and paradoxical. On one hand, the cGAS-STING axis promotes the clearance of CIN tumors through recruitment of immune cells, thus suppressing tumor progression. On the other hand, the cGAS-STING pathway has been described to be the major regulator in the promotion of metastasis of CIN tumors. Here, we review this dual role of the cGAS-STING pathway in the context of chromosomal instability and discuss the potential therapeutic implications of cGAS-STING signaling for targeting CIN tumors.

Serum Vitamin D Metabolites and CXCL10 Concentrations Associate With Survival in Dogs With Immune Mediated Disease

Background: Low vitamin D increases the risk of immune-mediated disease (IMD) in human beings and rodent models. Vitamin D metabolites, particularly 1,25(OH)2D3, modulate gene expression of immune cells and may attenuate immune pathways that drive IMD.

Hypothesis/objectives: Our primary hypothesis was that serum 25(OH)D3 and 1,25(OH)2D3, are reduced in patients with IMD and associate with poorer outcomes. We secondarily hypothesized serum 24,25(OH)2D3 would not be associated with disease or outcome. We also measured serum CXCL10 concentrations to determine if an increase occurs in dogs with IMD and in association with poorer survival.

Animals: We enrolled dogs diagnosed with IMD (n = 29) and healthy control dogs (n = 9) in the study with informed client consent.

Methods: Serum was collected and stored at −80°C until analyses. Serum vitamin D metabolites were measured by LC-MS/MS by an accredited laboratory. A commercially available canine-specific ELISA kit measured serum CXCL10.

Results: Serum 25(OH)D3 and 1,25(OH)2D3 were significantly reduced in dogs (n = 25) with IMD. Serum CXCL10 concentrations undetectable in all controls, and were 30 times higher overall in IMD dogs (n = 25; P = 0.004). CXL10 was, however, undetectable in 40% of dogs with IMD. Of the 60% of IMD dogs with increased CXCL10 concentrations, 5/25 had concentrations at the upper limit of quantification. The survival of those five dogs was significantly (P = 0.049) shorter (72 days) than all other dogs with IMD with measured CXCL10 concentrations. The median survival time (MST) for dogs with 25(OH)D3 concentrations ≤ the median was 106 days, while dogs with concentrations of 25(OH)D3 > the median did not achieve an MST.

Conclusions and clinical importance: Serum 25(OH)D3 and 1,25(OH)2D3, but not 24,25(OH)2D3 levels are reduced dogs with IMD. Vitamin D metabolites and CXCL10 may be useful prognostic markers and may be targets for adjunct therapy in canine IMD. These data support the future investigation of vitamin D analogs in the treatment of canine IMD.

MEG3 modulates TIGIT expression and CD4 + T cell activation through absorbing miR-23a

T cells are involved in bone marrow failure in aplastic anemia (AA). MEG3 is a long, non-coding RNA that can modulate target gene expression and T cell differentiation by acting as a microRNA sponge. Our previous study showed that T cell immunoglobulin and immunoreceptor tyrosine-based inhibition motif (ITIM) domain (TIGIT) plays a critical role in regulating CD4 + T cell functions. In this study, we found that MEG3 expression was significantly downregulated in CD4 + T cells derived from AA patients. MEG3 modulated CD4 + T cell proliferation and IFN-γ and TNF-α levels, as well as TIGIT, T-bet, and orphan nuclear receptor (RORγt) expression. Furthermore, MEG3 overexpression sequestered miR-23a and prompted TIGIT expression in CD4 + T cells. CD4 + T cells with MEG3 overexpression impeded expansion of Th1 and Th17 cells, restored the decreased red blood cell count, attenuated the increase in serum INF-γ and TNF-α levels, and lengthened median survival time, as well as upregulated mRNA levels of CD34, stem cell factor (SCF), and granulocyte/macrophage-colony-stimulating factor (GM-CSF) in bone marrow mononuclear cells of a mouse model. In conclusion, our study provides evidence that MEG3 regulated TIGIT expression and CD4 + T cell activation by absorbing miR-23a. These findings provide novel insight into autoimmune-mediated AA.

1,4-β-d-Glucomannan from Dendrobium officinale Activates NF-кB via TLR4 to Regulate the Immune Response

2,3-O-acetylated-1,4-β-d-glucomannan (DOP-1-1) is a polysaccharide isolated from the stem of Dendrobium officinale. DOP-1-1 has been demonstrated to have remarkable immunomodulatory properties, but little is known about the influence of its structural diversity on bioactivity (and even less about the exact mechanism underlying its immune responses). First, DOP-1-1 was stabilized at different temperatures and pH conditions based on differential scanning calorimetry and size exclusion-chromatography–high-performance liquid chromatography. Then, a detailed study on the effects of DOP-1-1 on a human leukemia monocytic cell line (THP-1) under normal conditions was undertaken. DOP-1-1 promoted the translocation of nuclear factor-kappa B (NF-κB) and degradation of IκB proteins. The expression of genes and proteins closely associated with the immune, survival and apoptotic functions of NF-κB were analyzed by quantitative real-time RT-PCR. Furthermore, CCL4 and IP10 were confirmed to be the novel targets of the immune response stimulated by DOP-1-1. The phosphorylation of NF-кB was inhibited by treatment with a toll-like receptor 4 (TLR4) antagonist (TAK-242) and myeloid differentiation factor 88 (MyD88) inhibitor (ST2825). These data suggested: (i) the O-acetylated glucomannan DOP-1-1 is present in the steady state in low-pH solutions; (ii) DOP-1-1 can induce an immune response through NF-кB mediated by a TLR4 signaling pathway; and (iii) CCL4 and IP10 could be the novel targets of the immune response stimulated by O-acetylated glucomannan.

Nuclear localization of metabolic enzymes in immunity and metastasis

Metabolism is essential to all living organisms that provide cells with energy, regulators, building blocks, enzyme cofactors and signaling molecules, and is in tune with nutritional conditions and the function of cells to make the appropriate developmental decisions or maintain homeostasis. As a fundamental biological process, metabolism state affects the production of multiple metabolites and the activation of various enzymes that participate in regulating gene expression, cell apoptosis, cancer progression and immunoreactions. Previous studies generally focus on the function played by the metabolic enzymes in the cytoplasm and mitochondrion. In this review, we conclude the role of them in the nucleus and their implications for cancer progression, immunity and metastasis.