KRT17High/CXCL8+ tumor cells display both classical and basal features and regulate myeloid infiltration in the pancreatic cancer microenvironment

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is generally divided in two subtypes, classical and basal. Recently, single cell RNA sequencing has uncovered the co-existence of basal and classical cancer cells, as well as intermediary cancer cells, in individual tumors. The latter remains poorly understood; here, we sought to characterize them using a multimodal approach.

EXPERIMENTAL DESIGN

We performed subtyping on a single cell RNA sequencing dataset containing 18 human PDAC samples to identify multiple intermediary subtypes. We generated patient-derived PDAC organoids for functional studies. We compared single cell profiling of matched blood and tumor samples to measure changes in the local and systemic immune microenvironment. We then leveraged longitudinally patient-matched blood to follow individual patients over the course of chemotherapy.

RESULTS

We identified a cluster of KRT17-high intermediary cancer cells that uniquely express high levels of CXCL8 and other cytokines. The proportion of KRT17High/CXCL8+ cells in patient tumors correlated with intra-tumoral myeloid abundance, and, interestingly, high pro-tumor peripheral blood granulocytes, implicating local and systemic roles. Patient-derived organoids maintained KRT17High/CXCL8+cells and induced myeloid cell migration in an CXCL8-dependent manner. In our longitudinal studies, plasma CXCL8 decreased following chemotherapy in responsive patients, while CXCL8 persistence portended worse prognosis.

CONCLUSIONS

Through single cell analysis of PDAC samples we identified KRT17High/CXCL8+ cancer cells as an intermediary subtype, marked by a unique cytokine profile and capable of influencing myeloid cells in the tumor microenvironment and systemically. The abundance of this cell population should be considered for patient stratification in precision immunotherapy.

Serum CXCL8 and CXCR2 as diagnostic biomarkers for noninvasive screening of cervical cancer

BACKGROUND

Cervical cancer (CC) is the fourth most frequently diagnosed cancer and the fourth leading cause of cancer-related death in women. Identifying new biomarkers for the early detection of CC is an essential requirement in this field. CXCL8 was originally discovered because of its role in inflammation by binding to CXCR1 and CXCR2; however, it is now known to play an important role in cancer. In this study, we aimed to evaluate the expression levels of potential biomarkers (CXCL8, CXCR1, and CXCR2) and to explore their diagnostic potential in CC.

METHODS

The expression levels of serum CXCL8, CXCR1, and CXCR2 were investigated by kit method on Immulite-1000 in 30 healthy volunteers, 30 precancerous patients and 70 CC patients.

RESULTS

The results indicated that the expression of CXCL8 and CXCR2 was significantly higher in the serum of CC patients than in healthy volunteers, similar to the well-established tumor marker (squamous-cell cancerantigen [SCC]). Receiver operating characteristic analyses showed that the combination of CXCL8, CXCR2, and SCC had the highest diagnostic sensitivity and area under the curve value. Meanwhile, the positive predictive value and negative predictive value were not very low. Moreover, high concentrations of CXCL8 and CXCR2 are associated with an increased risk of CC.

CONCLUSIONS

In conclusion, our data demonstrated that combined serum CXCL8, CXCR2, and SCC measurements are helpful for CC diagnosis and can be used as potential biomarkers for the early detection of CC. Cytokines, such as CXCL8 and CXCR2, can be easily measured in most university hospital laboratories and in some private laboratories with a routine test.

Castration-mediated IL-8 promotes myeloid infiltration and prostate cancer progression

Unlike several other tumor types, prostate cancer rarely responds to immune checkpoint blockade (ICB). To define tumor cell intrinsic factors that contribute to prostate cancer progression and resistance to ICB, we analyzed prostate cancer epithelial cells from castration-sensitive and -resistant samples using implanted tumors, cell lines, transgenic models and human tissue. We found that castration resulted in increased expression of interleukin-8 (IL-8) and its probable murine homolog Cxcl15 in prostate epithelial cells. We showed that these chemokines drove subsequent intratumoral infiltration of tumor-promoting polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), which was largely abrogated when IL-8 signaling was blocked genetically or pharmacologically. Targeting IL-8 signaling in combination with ICB delayed the onset of castration resistance and increased the density of polyfunctional CD8 T cells in tumors. Our findings establish a novel mechanism by which castration mediates IL-8 secretion and subsequent PMN-MDSC infiltration, and highlight blockade of the IL-8/CXCR2 axis as a potential therapeutic intervention.

Human Naive T Cells Express Functional CXCL8 and Promote Tumorigenesis

Naive T cells are thought to be functionally quiescent. In this study, we studied and compared the phenotype, cytokine profile, and potential function of human naive CD4+ T cells in umbilical cord and peripheral blood. We found that naive CD4+ T cells, but not memory T cells, expressed high levels of chemokine CXCL8. CXCL8+ naive T cells were preferentially enriched CD31+ T cells and did not express T cell activation markers or typical Th effector cytokines, including IFN-γ, IL-4, IL-17, and IL-22. In addition, upon activation, naive T cells retained high levels of CXCL8 expression. Furthermore, we showed that naive T cell-derived CXCL8 mediated neutrophil migration in the in vitro migration assay, supported tumor sphere formation, and promoted tumor growth in an in vivo human xenograft model. Thus, human naive T cells are phenotypically and functionally heterogeneous and can carry out active functions in immune responses.

Developmental Vitamin D Availability Impacts Hematopoietic Stem Cell Production

Vitamin D insufficiency is a worldwide epidemic affecting billions of individuals, including pregnant women and children. Despite its high incidence, the impact of active vitamin D3 (1,25(OH)D3) on embryonic development beyond osteo-regulation remains largely undefined. Here, we demonstrate that 1,25(OH)D3 availability modulates zebrafish hematopoietic stem and progenitor cell (HSPC) production. Loss of Cyp27b1-mediated biosynthesis or vitamin D receptor (VDR) function by gene knockdown resulted in significantly reduced runx1 expression and Flk1+cMyb+ HSPC numbers. Selective modulation in vivo and in vitro in zebrafish indicated that vitamin D3 acts directly on HSPCs, independent of calcium regulation, to increase proliferation. Notably, ex vivo treatment of human HSPCs with 1,25(OH)D3 also enhanced hematopoietic colony numbers, illustrating conservation across species. Finally, gene expression and epistasis analysis indicated that CXCL8 (IL-8) was a functional target of vitamin D3-mediated HSPC regulation. Together, these findings highlight the relevance of developmental 1,25(OH)D3 availability for definitive hematopoiesis and suggest potential therapeutic utility in HSPC expansion.

The effects of corticosteroids on COPD lung macrophages: a pooled analysis

BACKGROUND

There is large variation in the therapeutic response to inhaled corticosteroids (ICS) in COPD patients. We present a pooled analysis of our previous studies investigating the effects of corticosteroids on lung macrophages, in order to robustly determine whether corticosteroid sensitivity in COPD cells is reduced compared to controls, and also to evaluate the degree of between individual variation in drug response.

METHODS

Data from 20 never smokers (NS), 27 smokers (S) and 45 COPD patients was used. Lung macropahges had been stimulated with lipopolysaccharide (LPS), with or without the corticosteroid dexamethasone, and tumour necrosis factor (TNF)-α, interleukin (IL)-6 and chemokine C-X-C motif ligand (CXCL) 8 production was measured.

RESULTS

There was no difference in the anti-inflammatory effects of corticosteroids when comparing group mean data of COPD patients versus controls. The inhibition of TNF-α and IL-6 was greater than CXCL8. The effects of corticosteroids varied considerably between subjects, particularly at lower corticosteroid concentrations.

CONCLUSIONS

We confirm that overall corticosteroid sensitivity in COPD lung macrophages is not reduced compared to controls. The varied effect of corticosteroids between subjects suggests that some individuals have an inherently poor corticosteroid response. The limited suppression of lung macrophage derived CXCL8 may promote neutrophilic inflammation in COPD.

Cxcl8-l1 and Cxcl8-l2 are required in the zebrafish defense against Salmonella Typhimurium

In recent years zebrafish has emerged as an excellent model for studying the Cxcl8 signaling pathway in inflammation elicited upon tissue damage or infection. Zebrafish has two true homologs of mammalian CXCL8, named Cxcl8-l1 and Cxcl8-l2. Previously, we have shown that in wound-associated inflammation, these chemokines are up-regulated and are relevant for neutrophil recruitment. In infections, no such knowledge is available as most studies performed on this subject in zebrafish have mainly focused on Cxcl8-l1 even though Cxcl8-l2 shares higher homology with human CXCL8. In this study, we aimed to address the biological function of both zfCxcl8s in infection to improve our understanding of their respective roles under different inflammatory conditions. Gene expression analysis first confirmed that both Cxcl8-l1 and l2 are induced upon infection or in PAMP-elicited inflammatory processes. In addition, we also found that cxcl8-deficient larvae show higher susceptibility to Salmonella enterica serovar Typhimurium (S. Typhimurium) infection, reduced neutrophil recruitment to the infection site assayed in the line Tg(mpx:gfp), and decreased bacterial clearance. These data indicate that both zebrafish Cxcl8s play important roles in neutrophil recruitment and in the inflammatory response elicited upon infection or tissue damage, suggesting that even though the divergence of lower vertebrates and humans from a common ancestor occurred about 450 millions years ago, the basic principles of neutrophil recruitment are apparently conserved in all vertebrates.

Activity of sputum p38 MAPK is correlated with airway inflammation and reduced FEV1 in COPD patients

BACKGROUND

Inflammation and remodeling of the small airways are major determinants of the progression and severity of COPD. The present study explored the correlation between sputum p38 mitogen-activated protein kinase (MAPK) activity and airway inflammation and reduction of lung function in the patients with chronic obstructive pulmonary disease (COPD).

MATERIAL AND METHODS

Sputum samples were collected from 48 COPD patients and 12 healthy persons. Sputum p38 MAPK activity was measured by Western blotting and sputum levels of CXCL8 and neutrophil, and lung function was measured. The correlation between p38MAPK activity and airway inflammation and reduction of lung function was analyzed.

RESULTS

Our results showed the significantly increased expression of phospho-p38 MAPK and CXCL8 in the sputum samples of the COPD patients. The p38 MAPK activity was remarkably correlated with the CXCL8 level and neutrophils infiltration in the airway, and the decline of lung function in the COPD patients.

CONCLUSIONS

These findings suggest the pivotal role of p38 MAPK in the airway inflammation of COPD patients. We propose p38 MAPK as a potential target for the treatment of COPD.

Cxcl8 (IL-8) mediates neutrophil recruitment and behavior in the zebrafish inflammatory response

Neutrophils play a pivotal role in the innate immune response. The small cytokine CXCL8 (also known as IL-8) is known to be one of the most potent chemoattractant molecules that, among several other functions, is responsible for guiding neutrophils through the tissue matrix until they reach sites of injury. Unlike mice and rats that lack a CXCL8 homolog, zebrafish has two distinct CXCL8 homologs: Cxcl8-l1 and Cxcl8-l2. Cxcl8-l1 is known to be upregulated under inflammatory conditions caused by bacterial or chemical insult but until now the role of Cxcl8s in neutrophil recruitment has not been studied. In this study we show that both Cxcl8 genes are upregulated in response to an acute inflammatory stimulus, and that both are crucial for normal neutrophil recruitment to the wound and normal resolution of inflammation. Additionally, we have analyzed neutrophil migratory behavior through tissues to the site of injury in vivo, using open-access phagocyte tracking software PhagoSight. Surprisingly, we observed that in the absence of these chemokines, the speed of the neutrophils migrating to the wound was significantly increased in comparison with control neutrophils, although the directionality was not affected. Our analysis suggests that zebrafish may possess a subpopulation of neutrophils whose recruitment to inflamed areas occurs independently of Cxcl8 chemokines. Moreover, we report that Cxcl8-l2 signaled through Cxcr2 for inducing neutrophil recruitment. Our study, therefore, confirms the zebrafish as an excellent in vivo model to shed light on the roles of CXCL8 in neutrophil biology.

Interleukin-8 (IL-8) over-production and autocrine cell activation are key factors in monomethylarsonous acid [MMA(III)]-induced malignant transformation of urothelial cells

The association between chronic human exposure to arsenicals and bladder cancer development is well recognized; however, the underlying molecular mechanisms have not been fully determined. We propose that inflammatory responses can play a pathogenic role in arsenic-related bladder carcinogenesis. In previous studies, it was demonstrated that chronic exposure to 50 nM monomethylarsenous acid [MMA(III)] leads to malignant transformation of an immortalized model of urothelial cells (UROtsa), with only 3 mo of exposure necessary to trigger the transformation-related changes. In the three-month window of exposure, the cells over-expressed pro-inflammatory cytokines (IL-1β, IL-6 and IL-8), consistent with the sustained activation of NFKβ and AP1/c-jun, ERK2, and STAT3. IL-8 was over-expressed within hours after exposure to MMA(III), and sustained over-expression was observed during chronic exposure. In this study, we profiled IL-8 expression in UROtsa cells exposed to 50 nM MMA(III) for 1 to 5 mo. IL-8 expression was increased mainly in cells after 3 mo MMA(III) exposure, and its production was also found increased in tumors derived from these cells after heterotransplantation in SCID mice. UROtsa cells do express both receptors, CXCR1 and CXCR2, suggesting that autocrine cell activation could be important in cell transformation. Supporting this observation and consistent with IL-8 over-expression, CXCR1 internalization was significantly increased after three months of exposure to MMA(III). The expression of MMP-9, cyclin D1, bcl-2, and VGEF was significantly increased in cells exposed to MMA(III) for 3 mo, but these mitogen-activated kinases were significantly decreased after IL-8 gene silencing, together with a decrease in cell proliferation rate and in anchorage-independent colony formation. These results suggest a relevant role of IL-8 in MMA(III)-induced UROtsa cell transformation.

Influence of NFkappaB inhibitors on IL-1beta-induced chemokine CXCL8 and -10 expression levels in intestinal epithelial cell lines: glucocorticoid ineffectiveness and paradoxical effect of PDTC

PURPOSE

Activation of intestinal epithelial cell (IEC) nuclear factor kappaB (NFkappaB) and the consequent chemokine upregulation are crucial events in inflammatory bowel disease (IBD) pathogenesis. Not much is known about the consequences of NFkappaB inhibition in terms of chemokine expression in intestinal cells. Therefore, we aimed to evaluate the efficacy of compounds known to disrupt the NFkappaB pathway on NFkappaB transcriptional activity and CXCL8 and CXCL10 gene expression in intestinal cell lines.

METHODS

The influence of NFkappaB inhibitors (dexamethasone, pyrrolidine dithiocarbamate (PDTC) and BAY 11-7082) on IL-1beta-induced NFkappaB transcriptional activity was investigated by transient transfection of Caco-2 cells with an NFkappaB-secreted alkaline phosphatase reporter plasmid. Il-1beta stimulated CXCL8 and CXCL10 mRNA and protein expression and was studied in Caco-2 and HT29 cells in the presence and absence of the NFkappaB inhibitors by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent serologic assay, respectively. To reveal alternative signalling cascades, experiments were also performed in the presence of the p38MAPK inhibitor SB 203580 and the ERK inhibitor PD 98059.

RESULTS

Dexamethasone did not downregulate chemokine expression sufficiently, probably due to a lack of glucocorticoid receptors in these cells. While BAY11-7082 inhibited chemokine expression, PDTC led to a paradoxical upregulation of CXCL8 in Caco-2 cells, which could be prevented by inhibition of p38MAPK.

CONCLUSION

These data explain the frequent unresponsiveness of IBD to glucocorticoid treatment and suggest that alternative NFkappaB inhibition in IECs might be of use in IBD therapy. Drug development based on measuring anti-NFkappaB activity might be misleading and should therefore also include studies on relevant gene products.

Interleukin-8 is essential for normal urothelial cell survival

Interleukin-8 (IL-8; CXCL8) has been shown to play a role in multiple cellular processes. Here, we report an additional role of IL-8 as a growth and essential survival factor for normal human urothelial cells. Supplementing exogenous recombinant human IL-8 to normal urothelial cells promoted cell growth through the Akt pathway. Inhibition of IL-8 expression by small inhibitory RNA (siRNA) caused normal urothelial cells to die. Addition of recombinant human IL-8 rescued the normal urothelial cells treated with IL-8 siRNA. This rescue effect could be blocked by antibodies to the IL-8 receptor CXCR1 but not by CXCR2, suggesting that normal urothelial cells normally have IL-8 autocrine or paracrine activity for survival and growth mediated by CXCR1. IL-8 mRNA levels were lower in samples from patients with interstitial cystitis, a urinary bladder disorder associated with urothelial cell dysfunction and/or loss. Taken together, these results suggest that IL-8 is an important normal urothelial growth factor and is necessary for normal urothelial cell survival in vitro and in vivo. Lower IL-8 expression levels in the urinary bladder may contribute to pathophysiology of interstitial cystitis.

Cytokines in urine in elderly subjects with acute cystitis and asymptomatic bacteriuria

OBJECTIVE

Searching for useful diagnostic tools to discriminate between asymptomatic bacteriuria (ASB) and acute cystitis, this study compared urinary levels of cytokines/chemokines and leukocyte esterase in three groups of elderly subjects; those with acute cystitis, those with ASB, and those without bacteriuria.

DESIGN

Comparative laboratory.

SETTING

Primary care.

SUBJECTS

A total of 16 patients with acute cystitis, 24 subjects with ASB, and 20 controls without bacteriuria, all of whom were aged 80 or over.

MAIN OUTCOME MEASURES

Urinary levels of IL-1 beta, TNF-alpha, IL-12, IL-18, CXCL1 (GRO-alpha), CXCL8 (IL-8), CCL2 (MCP-1), IL-6, IL-10, and leukocyte esterase.

RESULTS

Urinary levels of CXCL1, CXCL8, and IL-6 were significantly higher in acute cystitis patients than in the ASB group. The sensitivities and specificities for CXCL8, IL-6, and leukocyte esterase to discriminate between acute cystitis and ASB were 63% (95% CI 36-84) and 96% (95% CI 77-100) (cut-off > 285 pg/mg creatinine), 81% (95% CI 54-95) and 96% (95% CI 77-100) (cut-off > 30 pg/mg creatinine), and 88% (95% CI 60-98) and 79% (95% CI 57-92) (cut-off > 2, on a scale of 0-4), respectively.

CONCLUSIONS

The results indicate that measurement of urinary cytokines, and also leukocyte esterase, when using a cut-off value > 2, could be useful in clinical practice to discriminate between symptomatic and asymptomatic urinary tract infections in the elderly. A combination of IL-6 and leukocyte esterase could be even more useful. This needs to be evaluated in prospective studies on the diagnosis and treatment of urinary tract infections in an elderly population.

The development of clinical signs of rheumatoid synovial inflammation is associated with increased synthesis of the chemokine CXCL8 (interleukin-8)

Paired synovial tissue samples were obtained from both clinically uninvolved (CU) and clinically involved (CI) knee joints of eight rheumatoid arthritis (RA) patients. In addition, biopsies were taken from five control subjects. We observed the expression of the chemokines CXCL8, CXCL9, CXCL10, CCL2 and CCL4 in CI and CU joints of RA patients. In particular, CXCL8 protein levels were specifically increased in CI joints compared with CU joints, which was confirmed by immunohistochemistry and in situ hybridization.