Interleukin-8 messenger ribonucleic acid expression correlates with tumor progression, tumor angiogenesis, patient survival, and timing of relapse in non-small-cell lung cancer

SLC25A21 correlates with the prognosis of adult acute myeloid leukemia through inhibiting the growth of leukemia cells via downregulating CXCL8

In recent years, targeting mitochondrial apoptosis has emerged as a promising therapeutic strategy for Acute Myeloid Leukemia (AML). The SLC25 family of mitochondrial carriers plays a critical role in maintaining mitochondrial function and regulating apoptosis. However, the role of SLC25A21, an oxodicarboxylate carrier, in AML progression and its potential as a prognostic biomarker remain underexplored. This study aimed to further investigate the role, molecular mechanism, and potential clinical value of SLC25A21 in AML progression. The transcript levels of SLC25A21 in bone marrow specimens were analyzed using real-time quantitative polymerase chain reaction. The correlation between SLC25A21 expression and the prognosis of AML was assessed through survival analysis. Findings revealed that SLC25A21 was downregulated in adult AML, and the low expression of SLC25A21 was correlated with worse prognosis for AML patients. Furthermore, overexpression of SLC25A21 inhibited cell proliferation and cell cycle progression, and was correlated with apoptosis through mitochondrial apoptosis signaling pathway. C-X-C motif chemokine ligand 8 (CXCL8) was identified as a downstream target of SLC25A21. These functions of SLC25A21 could be rescued by the overexpression of CXCL8. Moreover, SLC25A21 overexpression significantly suppressed the growth of xenograft tumors. In conclusion, the low SLC25A21 expression is correlated with poor clinical outcome. The overexpression of SLC25A21 inhibited the AML cell survival and proliferation by dysregulating the expression of CXCL8. SLC25A21 might be a potential prognostic marker and a treatment target for AML.

Tumor-associated macrophages in non-small-cell lung cancer: From treatment resistance mechanisms to therapeutic targets

Non-small cell lung cancer (NSCLC) remains one of the leading causes of cancer-related deaths worldwide. Different treatment approaches are typically employed based on the stage of NSCLC. Common clinical treatment methods include surgical resection, drug therapy, and radiation therapy. However, with the introduction and utilization of immune checkpoint inhibitors, cancer treatment has entered a new era, completely revolutionizing the treatment landscape for various cancers and significantly improving overall patient survival. Concurrently, treatment resistance often poses a critical challenge, with many patients experiencing disease progression following an initial response due to treatment resistance. Increasing evidence suggests that the tumor microenvironment (TME) plays a pivotal role in treatment resistance. Tumor-associated macrophages (TAMs) within the TME can promote treatment resistance in NSCLC by secreting various cytokines activating signaling pathways, and interacting with other immune cells. Therefore, this article will focus on elucidating the key mechanisms of TAMs in treatment resistance and analyze how targeting TAMs can reduce the levels of treatment resistance in NSCLC, providing a comprehensive understanding of the principles and approaches to overcome treatment resistance in NSCLC.

Targeting KRAS and SHP2 signaling pathways for immunomodulation and improving treatment outcomes in solid tumors

Historically, KRAS has been considered 'undruggable' inspite of being one of the most frequently altered oncogenic proteins in solid tumors, primarily due to the paucity of pharmacologically 'druggable' pockets within the mutant isoforms. However, pioneering developments in drug design capable of targeting the mutant KRAS isoforms especially KRASG12C-mutant cancers, have opened the doors for emergence of combination therapies comprising of a plethora of inhibitors targeting different signaling pathways. SHP2 signaling pathway, primarily known for activation of intracellular signaling pathways such as KRAS has come up as a potential target for such combination therapies as it emerged to be the signaling protein connecting KRAS and the immune signaling pathways and providing the link for understanding the overlapping regions of RAS/ERK/MAPK signaling cascade. Thus, SHP2 inhibitors having potent tumoricidal activity as well as role in immunomodulation have generated keen interest in researchers to explore its potential as combination therapy in KRAS mutant solid tumors. However, the excitement with these combination therapies need to overcome challenges thrown up by drug resistance and enhanced toxicity. In this review, we will discuss KRAS and SHP2 signaling pathways and their roles in immunomodulation and regulation of tumor microenvironment and also analyze the positive effects and drawbacks of the different combination therapies targeted at these signaling pathways along with their present and future potential to treat solid tumors.

Therapeutic Peptide RF16 Derived from CXCL8 Inhibits MDA-MB-231 Cell Invasion and Metastasis

Interleukin (IL)-8 plays a vital role in regulating inflammation and breast cancer formation by activating CXCR1/2. We previously designed an antagonist peptide, (RF16), to inhibits the activation of downstream signaling pathways by competing with IL-8 in binding to CXCR1/2, thereby inhibiting IL-8-induced chemoattractant monocyte binding. To evaluate the effect of the RF16 peptide on breast cancer progression, triple-negative MDA-MB-231 and ER-positive MCF-7 breast cancer cells were used to investigate whether RF16 can inhibit the IL-8-induced breast cancer metastasis. Using growth, proliferation, and invasiveness assays, the results revealed that RF16 reduced cell proliferation, migration, and invasiveness in MDA-MB-231 cells. The RF16 peptide also regulated the protein and mRNA expressions of epithelial-mesenchymal transition (EMT) markers in IL-8-stimulated MDA-MB-231 cells. It also inhibited downstream IL-8 signaling and the IL-8-induced inflammatory response via the mitogen-activated protein kinase (MAPK) and Phosphoinositide 3-kinase (PI3K) pathways. In the xenograft tumor mouse model, RF16 synergistically reinforces the antitumor efficacy of docetaxel by improving mouse survival and retarding tumor growth. Our results indicate that RF16 significantly inhibited IL-8-stimulated cell growth, migration, and invasion in MDA-MB-231 breast cancer cells by blocking the activation of p38 and AKT cascades. It indicated that the RF16 peptide may serve as a new supplementary drug for breast cancer.

Expression of CXCL8 (IL-8) in the Pathogenesis of T-Cell Acute Lymphoblastic Leukemia Patients

Background Inflammation plays a very important role in the pathogenesis of a wide range of diseases, such as atherosclerosis myocardial infarction, sepsis, rheumatoid arthritis, and cancer. This study aimed to investigate the association of IL-8 in T-cell acute lymphoblastic leukemia (T-ALL) patients. Methodology IL-8 levels were estimated in 52 individuals. Of the study population, 26 were T-ALL patients (all phases of leukemia were included in the study) and 26 were disease-free healthy volunteers. In this study, we employed flow cytometry, enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction test, and western blot analysis. Results IL-8 was significantly higher in all T-ALL patients than in healthy volunteers. IL-8 levels showed a significant positive correlation in T-ALL patients at the genomic and proteomic levels. Conclusions Higher serum IL-8 levels were associated with the advanced disease stage of the clinicopathological parameters. Our results indicate that monitoring IL-8 has a role in modulating disease sensing in T-ALL and may represent a target for innovative diagnostic and therapeutic strategies.

TRAIL receptors promote constitutive and inducible IL-8 secretion in non-small cell lung carcinoma

Interleukin-8 (IL-8/CXCL8) is a pro-angiogenic and pro-inflammatory chemokine that plays a role in cancer development. Non-small cell lung carcinoma (NSCLC) produces high amounts of IL-8, which is associated with poor prognosis and resistance to chemo-radio and immunotherapy. However, the signaling pathways that lead to IL-8 production in NSCLC are unresolved. Here, we show that expression and release of IL-8 are regulated autonomously by TRAIL death receptors in several squamous and adenocarcinoma NSCLC cell lines. NSCLC constitutively secrete IL-8, which could be further enhanced by glucose withdrawal or by treatment with TRAIL or TNFα. In A549 cells, constitutive and inducible IL-8 production was dependent on NF-κB and MEK/ERK MAP Kinases. DR4 and DR5, known regulators of these signaling pathways, participated in constitutive and glucose deprivation-induced IL-8 secretion. These receptors were mainly located intracellularly. While DR4 signaled through the NF-κB pathway, DR4 and DR5 both regulated the ERK-MAPK and Akt pathways. FADD, caspase-8, RIPK1, and TRADD also regulated IL-8. Analysis of mRNA expression data from patients indicated that IL-8 transcripts correlated with TRAIL, DR4, and DR5 expression levels. Furthermore, TRAIL receptor expression levels also correlated with markers of angiogenesis and neutrophil infiltration in lung squamous carcinoma and adenocarcinoma. Collectively, these data suggest that TRAIL receptor signaling contributes to a pro-tumorigenic inflammatory signature associated with NSCLC.

Mesoporous Silica Particles Functionalized with Newly Extracted Fish Oil (Omeg@Silica) Reducing IL-8 Counteract Cell Migration in NSCLC Cell Lines

Lung cancer is one of the leading forms of cancer in developed countries. Interleukin-8 (IL-8), a pro-inflammatory cytokine, exerts relevant effects in cancer growth and progression, including angiogenesis and metastasis in lung cancer. Mesoporous silica particles, functionalized with newly extracted fish oil (Omeg@Silica), are more effective than the fish oil alone in anti-proliferative and pro-apoptotic effects in non-small cell lung cancer (NSCLC) cell lines. The mechanisms that explain this efficacy are not yet understood. The aim of the present study is therefore to decipher the anti-cancer effects of a formulation of Omeg@Silica in aqueous ethanol (FOS) in adenocarcinoma (A549) and muco-epidermoid (NCI-H292) lung cancer cells, evaluating cell migration, as well as IL-8, NF-κB, and miRNA-21 expression. Results show that in both cell lines, FOS was more efficient than oil alone, in decreasing cell migration and IL-8 gene expression. FOS reduced IL-8 protein release in both cell lines, but this effect was only stronger than the oil alone in A549. In A549, FOS was able to reduce miRNA-21 and transcription factor NF-κB nuclear expression. Taken together, these data support the potential use of the Omeg@Silica as an add-on therapy for NSCLC. Dedicated studies which prove clinical efficacy are needed.

High expression level of CXCL1/GROα is linked to advanced stage and worse survival in uterine cervical cancer and facilitates tumor cell malignant processes

Background

CXCL1 belongs to a member of the ELR + CXC chemokine subgroups that also known as GRO-alpha. It has been recognized that several types of human cancers constitutively express CXCL1, which may serve as a crucial mediator involved in cancer development and metastasis via an autocrine and/or paracrine fashion. However, the expression pattern and clinical significance of CXCL1 in human uterine cervix cancer (UCC), as well as its roles and mechanisms in UCC tumor biology remains entirely unclear.

Methods

The expression and clinical significance of CXCL1 in UCC tissues was explored using immunohistochemistry and bioinformatics analyses. The expression and effects of CXCL1 in HeLa UCC cells were assessed using ELISA, CCK-8 and transwell assays. Western blotting experiments were performed to evaluate the potential mechanism of CXCL1 on malignant behaviors of HeLa UCC cells.

Results

The current study demonstrated that CXCL1 was expressed in HeLa UCC cells, PHM1-41 human immortalized cervical stromal cells, as well as cervical tissues, with UCC tissues having an evidently high level of CXCL1. This high level of CXCL1 in cancer tissues was notably related to poor clinical stages and worse survival probability, rather than tumor infiltration and patient age. In addition, CXCL1 expression was extremely correlated with CCL20, CXCL8 and CXCL3 cancer-associated chemokines expression. In vitro, the growth and migration abilities of HeLa cells were significantly enhanced in the presence of exogenous CXCL1. Gain-function assay revealed that CXCL1 overexpression significantly promoted growth and migration response in HeLa cells in both autocrine and paracrine manners. Finally, we found that CXCL1 overexpression in HeLa cells influenced the expression of ERK signal-related genes, and HeLa cell malignant behaviors derived from CXCL1 overexpression were further interrupted in the presence of the ERK1/2 blocker.

Conclusion

Our findings demonstrate the potential roles of CXCL1 as a promoter and a novel understanding of the functional relationship between CXCL1 and the ERK signaling pathway in UCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09749-0.

A CGA/EGFR/GATA2 positive feedback circuit confers chemoresistance in gastric cancer

De novo and acquired resistance are major impediments to the efficacy of conventional and targeted cancer therapy. In unselected gastric cancer (GC) patients with advanced disease, trials combining chemotherapy and an anti-EGFR monoclonal antibody have been largely unsuccessful. In an effort to identify biomarkers of resistance so as to better select patients for such trials, we screened the secretome of chemotherapy-treated human GC cell lines. We found that levels of CGA, the α-subunit of glycoprotein hormones, were markedly increased in the conditioned media of chemoresistant GC cells, and CGA immunoreactivity was enhanced in GC tissues that progressed on chemotherapy. CGA levels in plasma increased in GC patients who received chemotherapy, and this increase was correlated with reduced responsiveness to chemotherapy and poor survival. Mechanistically, secreted CGA was found to bind to EGFR and activate EGFR signaling, thereby conferring a survival advantage to GC cells. N-glycosylation of CGA at Asn52 and Asn78 is required for its stability, secretion, and interaction with EGFR. GATA2 was found to activate CGA transcription, whose increase, in turn, induced the expression and phosphorylation of GATA2 in an EGFR-dependent manner, forming a positive feedback circuit that was initiated by GATA2 autoregulation upon sublethal exposure to chemotherapy. Based on this circuit, combination strategies involving anti-EGFR therapies or targeting CGA with microRNAs (miR-708-3p and miR-761) restored chemotherapy sensitivity. These findings identify a clinically actionable CGA/EGFR/GATA2 circuit and highlight CGA as a predictive biomarker and therapeutic target in chemoresistant GC.

Integrated in silico and 3D in vitro model of macrophage migration in response to physical and chemical factors in the tumor microenvironment

Macrophages are abundant in the tumor microenvironment (TME), serving as accomplices to cancer cells for their invasion. Studies have explored the biochemical mechanisms that drive pro-tumor macrophage functions; however the role of TME interstitial flow (IF) is often disregarded. Therefore, we developed a three-dimensional microfluidic-based model with tumor cells and macrophages to study how IF affects macrophage migration and its potential contribution to cancer invasion. The presence of either tumor cells or IF individually increased macrophage migration directedness and speed. Interestingly, there was no additive effect on macrophage migration directedness and speed under the simultaneous presence of tumor cells and IF. Further, we present an in silico model that couples chemokine-mediated signaling with mechanosensing networks to explain our in vitro observations. In our model design, we propose IL-8, CCL2, and β-integrin as key pathways that commonly regulate various Rho GTPases. In agreement, in vitro macrophage migration remained elevated when exposed to a saturating concentration of recombinant IL-8 or CCL2 or to the co-addition of a sub-saturating concentration of both cytokines. Moreover, antibody blockade against IL-8 and/or CCL2 inhibited migration that could be restored by IF, indicating cytokine-independent mechanisms of migration induction. Importantly, we demonstrate the utility of an integrated in silico and 3D in vitro approach to aid the design of tumor-associated macrophage-based immunotherapeutic strategies.

Prognostic Impact of the Advanced Lung Cancer Inflammation Index (ALI) in Metastatic Non-Small Cell Lung Cancer Treated with First Line Chemotherapy

Background:

The advanced lung cancer inflammation index (ALI) has been reported to predict the overall survival in patients with advanced non-small cell lung cancer (NSCLC). However, no previous studies have examined the prognostic significance of ALI in metastatic NSCLC treated with first line chemotherapy. The objective of this study was to explore the relationship between ALI and the prognosis of metastatic NSCLC treated with first line chemotherapy.

Materials and Methods:

Data of 109 metastatic NSCLC patients who had completed first line treatment with chemotherapy was collected. A multivariate flexible parametric proportional-hazards model with restricted cubic splines (RCS) was used to explore and identify the independent prognostic factors, including clinical potential factors and ALI for the overall survival. Multivariate regression analysis was used to evaluate the potential prognostic factors associated with short survival less than 6 months. The analysis of the restricted mean survival time (RMST) method was used to estimate the event-free time from zero to 18 months.

Results:

The median OS was 10.9 months (95%CI 9.57-13.18) and median PFS was 7.5 months (95%CI 6.85-8.00).The multivariate survival analyses revealed two prognostic factors for worse survival: Poor ECOG PS (HR46.90; 95%CI 2.90-758.73; p=0.007) and progressive disease after completing the first line chemotherapy treatment (HR 2.85; 95%CI1.18-6.88; p=0.02),whereas a low ALI <11 referred to a non-significant prognostic factor (HR 1.42; 95%CI 0.67-3.01; p=0.364).The results of the multivariate regression analysis revealed that the low ALI and progressive disease status were significantly associated with the short survival outcome (OR 5.12; 95%CI 1.11-23.65; p=0.037; OR 12.57; 95%CI 3.00-52.73; p=0.001).

Conclusions:

A low ALI was associated with the short survival in metastatic NSCLC treated with chemotherapy. However, using ALI as a prognostic factor only was still too limited. Other considerable clinical prognostic factors should also be used simultaneously, which would have strong significant prognostic impacts.

Up-regulation of CXCL8 expression is associated with a poor prognosis and enhances tumor cell malignant behaviors in liver cancer

CXCL8, a member of CXC chemokines, was constitutively expressed in many types of human cancers, and its overexpression has been shown to play a critical role in promoting tumorigenesis. The purpose of the present study was to determine CXCL8 expression in a commercial human liver tissue microarray, and elucidate the effects and underlying mechanisms by which CXCL8 is involved in the malignant progression of human liver cancer. Our data showed that high level expression of CXCL8 in tissues with liver cancer was identified as compared with non-cancer tissues, and its up-regulation was closely associated with clinical stage and tumor infiltration. In vitro, exogenous CXCL8 at concentrations of 10, 20 or 40 ng/ml obviously stimulated the proliferation abilities of HepG2 cells. Coupled with this, 10, 20 or 40 ng/ml of exogenous CXCL8 also triggered a significant elevation in HepG2 cells migration. Additionally, overexpression of CXCL8 in HepG2 cells also resulted in increased cell proliferation and migration capacities. Finally, Western blotting analysis showed that overexpression of CXCL8 increased the expression of ERK, p-ERK and survivin, decreased the expression of caspase-3 and BAX at protein level.

Bioinformatics Analyses Reveals a Comprehensive Landscape of CXC Chemokine Family Functions in Non-Small Cell Lung Cancer

Backgrounds. Lung cancer is a major source of tumor-related death each year with non-small cell lung cancer (NSCLC) being a prevalent subtype. The metastasis from NSCLC to the brain usually imposes many neuron disorders. Previous studies have suggested that communications among cancer cells and interstitial cells are essential in tumorigenesis and are influenced by chemokines. In the tumor microenvironment, CXC chemokines can participate in the shifting of immune cells and manage tumor cell condition, thus affecting the progression of cancer and patient destinies. However, the expression and values of CXC chemokine family in NSCLC have not been systematically illustrated using public databases. Methods. UALCAN, STRING, ONCOMINE, GeneMANIA, cBioPortal, GEPIA, TISIDB, TRRUST, TIMER, Kaplan-Meier Plotter, and R software were utilized in this study. Results. Based on the TIMER and UACLCAN databases, in LUAD patients, the expression levels of CXCL10, CXCL13, and CXCL14 were significantly elevated while the transcriptional levels of CXCL2/3/4/7/12/16 were significantly reduced; in LUSC patients, the expression levels of CXCL6/10/13/14 were significantly elevated while the expression levels of CXCL2/3/4/5/7/11/12/16/17 were significantly reduced. We found remarkable relevance between the pathological stages of LUAD patients and the expressions of CXCL8 (positive) and CXCL17 (negative). Similarly, there are significant correlations between the pathological stages of LUSC patients and the expressions of CXCL1/2/6/17. In LUAD, patients with low expression levels of CXCL1/4/7/8 and patients with high expression levels of CXCL12/14/16 were associated with a significantly better prognosis. But in LUSC, all correlations between chemokines and prognosis are statistically insignificant. Pairwise expression correlation analysis among CXC chemokines shows that there are 7 significant correlations (between CXCL1 and CXCL2, between CXCL1 and CXCL3, between CXCL1 and CXCL8, between CXCL2 and CXCL3, between CXCL4 and CXCL7, between CXCL9 and CXCL10, and between CXCL9 and CXCL11) in LUAD and 4 significant correlations (between CXCL1 and CXCL8, between CXCL2 and CXCL3, between CXCL4 and CXCL7, and between CXCL10 and CXCL11) in LUSC. Significant correlations between the expressions of CXC chemokines and the infiltration of six common types of immune cells were also discovered in both LUAD and LUSC. Conclusions. We provided a comprehensive landscape of the CXC chemokine family in LUAD and LUSC using the bioinformatics method and found differences between LUSC and LUAD in the field of CXC chemokines. Our study may help validate and identify known novel immunotherapeutic targets and prognostic biomarkers.

NF-κB inhibitors in treatment and prevention of lung cancer

Intracellular signalling pathways have provided excellent resource for drug development particularly in the development of cancer therapeutics. A wide variety of malignancies common in human exhibit aberrant NF-κB constitutive expression which results in tumorigenic processes and cancer survival in a variety of solid tumour, including pancreatic cancer, lung, cervical, prostate, breast and gastric carcinoma. Numerous evidences indicate that NF-κB signalling mechanism is mainly involved in the progression of several cancers which may intensify an enhanced knowledge on its role in disease particularly lung tumorigenesis. This has led to tremendous research in designing a variety of NF-κB antagonists with enhanced clinical applications through different approaches the most common being suppression of IκB kinase (IKK) beta activity. Many NF-κB inhibitors for lung cancer are now under clinical trials. Preliminary results of clinical trials for several of these agents include small-molecule inhibitors and monoclonal antibodies. A few combinatorial treatment therapies are currently under investigation in the clinics and have shown promise, particularly NF-κB inhibition associated with lung cancer.

Tumour Cell Secretome in Chemoresistance and Tumour Recurrence

Chemoresistance is a major factor driving tumour relapse and the high rates of cancer-related deaths. Understanding how cancer cells overcome chemotherapy-induced cell death is critical in promoting patient survival. One emerging mechanism of chemoresistance is the tumour cell secretome (TCS), an array of protumorigenic factors released by tumour cells. Chemotherapy exposure can also alter the composition of the TCS, known as therapy-induced TCS, and can promote tumour relapse and the formation of an immunosuppressive tumour microenvironment (TME). Here, we outline how the TCS can protect cancer cells from chemotherapy-induced cell death. We also highlight recent evidence describing how therapy-induced TCS can impact cancer stem cell (CSC) expansion and tumour-associated immune cells to enable tumour regrowth and antitumour immunity.

Expression profiling revealed keratins and interleukins as potential biomarkers in squamous cell carcinoma of horn in Indian bullocks (Bos indicus)

Horn cancer is most prevalent in Bos indicus and poorly defined genetic landscape makes disease diagnosis and treatment difficult. In this study, RNA-Seq and data analysis using CLC Genomics Workbench was employed to identify biomarkers associated with horn cancer. As a result, a total of 149 genes were found significant differentially expressed in horn cancer samples compared to horn normal samples. The study revealed 'keratins' and 'interleukins' as apex groups of significant differentially expressed genes (DEGs). Functional analysis showed that the upregulated keratins support metastasis of tumor via cell proliferation, migration, and affecting cell stability, while downregulated interleukins along with other associated chemokine receptors deprive the immune response to tumor posing clear path for metastasis of horn cancer. Combi-action of both the group facilitates the tumor microenvironment to reproduce tumorigenesis. Analysis of pathways enriched in DEGs and exemplified protein-protein interaction network indicated actual role of DEGs in horn cancer at a fine level. Important effect of deregulated expression of keratin and interleukin genes in horn cancer enrolling their candidacy as potential biomarkers for horn cancer prognosis. This study appraises the possibility to mitigate horn cancer at fine resolution to extract attainable identification of prognostic molecular portraits.

Hsp60 and IL-8 axis promotes apoptosis resistance in cancer

Background

Interleukin-8 (IL-8) and heat shock protein 60 (Hsp60) play crucial roles in cell survival and maintenance of cellular homoeostasis. However, cross talks between these two proteins are not defined.

Methods

IL-8 expression in tumour tissue sections was analysed by immunohistochemistry. IL-8 expression and release in cancer cells was quantified using enzyme-linked immunosorbent assay (ELISA). Apoptosis was quantified using caspase activity and Annexin-V/PI staining.

Results

We observed IL-8 release from cancer cells in response to histone deacetylase inhibitor, apicidin (Api), and non-competitive inhibitor of the sarco/endoplasmic reticulum Ca²⁺ ATPase, thapsigargin (TG). IL-8 release was increased upon TG-treatment. TG-induced IL-8 expression was reduced in the presence of Api in Bax-dependent manner. Increased apoptosis was associated with decreased IL-8 expression in response to combined treatment of TG and Api. TG and Api combination induced caspase-8 and caspase-9 dependent apoptosis. Hsp60 knockdown abrogated IL-8 expression induced by Api, TG, and their combination. The level of TGF-β, an upstream regulator of IL-8, was decreased upon Hsp60-silencing. Knocking down Hsp60 decreased IL-8 expression and its release in prostate cancer cell xenograft tumours in SCID mice.

Conclusion

This study describes the underlying mechanism associated with apoptosis resistance mediated via Hsp60-IL-8 axis in cancer.

Prognostic and Predictive Role of Angiogenic Markers in Non- Small Cell Lung Cancer

Objective:

Despite the existence of detailed consensus guidelines, challenges remain regarding the role angiogenetic factors on non-small cell lung cancer (NSCLC). This study was conducted to determine the role of the vascular endothelial growth factor (VEGF), interleukin-8 (IL-8) and angiopoietin2 (Ang2) in patients with NSCLC.

Methods:

This study included 64 consecutive patients with non-small cell lung cancer, who admitted to clinic. Pre-treatment serum VEGF, IL-8 and Ang2 levels were evaluated. Patients were treated according to internationally accepted guidelines.

Results:

VEGF and IL-8 serum levels of patients with both squamous cell carcinoma and adenocarcinoma were significantly higher than controls (p<0.05). In addition, IL-8 levels were lower among treatment-responders than non-responders (p:0.031). Impact of elevated or decreased levels of VEGF, Ang2 and IL-8 on survival was evaluated, accepting median level as reference. There was no correlation between the serum levels of VEGF, Ang2, IL-8 and survival.

Conclusion:

We found that the levels of angiogenic markers were significantly different between non-small cell lung cancer patients and controls. These markers could elicit more information related to stage and prognosis.

IKKβ targeting reduces KRAS-induced lung cancer angiogenesis in vitro and in vivo: A potential anti-angiogenic therapeutic target

OBJECTIVES

The ability of tumor cells to drive angiogenesis is an important cancer hallmark that positively correlates with metastatic potential and poor prognosis. Therefore, targeting angiogenesis is a rational therapeutic approach and dissecting proangiogenic pathways is important, particularly for malignancies driven by oncogenic KRAS, which are widespread and lack effective targeted therapies. Based on published studies showing that oncogenic RAS promotes angiogenesis by upregulating the proangiogenic NF-κB target genes IL-8 and VEGF, that NF-κB activation by KRAS requires the IKKβ kinase, and that targeting IKKβ reduces KRAS-induced lung tumor growth in vivo, but has limited effects on cell growth in vitro, we hypothesized that IKKβ targeting would reduce lung tumor growth by inhibiting KRAS-induced angiogenesis.

MATERIALS AND METHODS

To test this hypothesis, we targeted IKKβ in KRAS-mutant lung cancer cell lines either by siRNA-mediated transfection or by treatment with Compound A (CmpdA), a highly specific IKKβ inhibitor, and used in vitro and in vivo assays to evaluate angiogenesis.

RESULTS AND CONCLUSIONS

Both pharmacological and siRNA-mediated IKKβ targeting in lung cells reduced expression and secretion of NF-κB-regulated proangiogenic factors IL-8 and VEGF. Moreover, conditioned media from IKKβ-targeted lung cells reduced human umbilical vein endothelial cell (HUVEC) migration, invasion and tube formation in vitro. Furthermore, siRNA-mediated IKKβ inhibition reduced xenograft tumor growth and vascularity in vivo. Finally, IKKβ inhibition also affects endothelial cell function in a cancer-independent manner, as IKKβ inhibition reduced pathological retinal angiogenesis in a mouse model of oxygen-induced retinopathy. Taken together, these results provide a novel mechanistic understanding of how the IKKβ pathway affects human lung tumorigenesis, indicating that IKKβ promotes KRAS-induced angiogenesis both by cancer cell-intrinsic and cancer cell-independent mechanisms, which strongly suggests IKKβ inhibition as a promising antiangiogenic approach to be explored for KRAS-induced lung cancer therapy.

IL-8 regulates the stemness properties of cancer stem cells in the small-cell lung cancer cell line H446

PURPOSE

Cancer stem cells (CSCs) are a small population of cancer cells located within a tumor that are highly tumorigenic, capable of tumor initiation, and resistant to cancer therapies. We identified the potential genes involved in regulating stemness properties and investigated the mechanisms in small-cell lung cancer (SCLC).

MATERIALS AND METHODS

Whole transcriptome sequencing technology was used to screen the potential genes involved in regulating stemness properties from SCLC-SCs (uPAR+) and differentiated cells (uPAR-) in the H446 cell line. The selected genes were validated by quantitative reverse transcription PCR and ELISAs. The effect of IL-8 on stemness of sphere-forming cells was determined through tumor sphere formation, wound healing migration, and in vivo tumorigenesis assays.

RESULTS

In our study, uPAR+ and uPAR- cells showed different gene expression profiles. IL-8 was upregulated in SCLC sphere-forming cells. Blocking IL-8 expression with siRNA led to loss of stemness, including the self-renewal capability, migration, expression of stemness-related genes, and in vivo tumorigenicity, in sphere-forming cells. Consistently, exogenously added IL-8 enhanced stemness properties in parental cells.

CONCLUSION

IL-8 was upregulated in SCLC sphere-forming cells, and critical for the acquisition and/or maintenance of the stemness features in the SCLC cell line H446. Our results suggest that blocking IL-8 signaling may provide a novel therapeutic approach for targeting SCLC-SCs and improve treatment and outcomes in SCLC.

DACH1 antagonizes CXCL8 to repress tumorigenesis of lung adenocarcinoma and improve prognosis

BACKGROUND

C-X-C motif ligand 8 (CXCL8), known as a proinflammatory chemokine, exerts multiple effects on the proliferation, invasion, and migration of tumor cells via the autocrine or paracrine manner. Conversely, the human Dachshund homologue 1 (DACH1) is recognized as a tumor suppressor which retards the progression of various cancers. In prostate cancer, it has been demonstrated that DACH1 was negatively correlated with the expression of CXCL8 and able to antagonize the effects of CXCL8 on cellular migration. Herein, we explored the mechanisms by which DACH1 regulated the CXCL8 in non-small cell lung cancer (NSCLC).

METHODS

Public microarray and Kaplan-Meier plotter datasets were analyzed. Blood serum samples from lung adenocarcinoma (ADC) patients were collected for enzyme-linked immunosorbent assay (ELISA) analysis. Immunohistochemical staining was conducted on tissue microarray. Cell lines with stable expression of DACH1 were established, and relative gene expression was measured by Western blot, ELISA, real-time PCR, and human cytokine array. Correspondingly, cell lines transfected with shDACH1 were established, and relative gene expression was measured by real-time PCR and immunofluorescence array. Functional studies were performed by transwell and xenograft mice models. Luciferase reporter gene assay was applied to measure the regulation of DACH1 on CXCL8.

RESULTS

Our study indicated that CXCL8 both at the mRNA and protein level was associated with the high tumor burden of ADC. Correlational analyses in ADC cell lines and ADC tissues showed that DACH1 was inversely correlated with CXCL8. Meanwhile, patients with high DACH1 expression and low CXCL8 expression had prolonged time to death and recurrence. Moreover, we verified the inhibitory effects of DACH1 on CXCL8 both in vitro and in vivo. Mechanism studies proved that DACH1 transcriptionally repressed CXCL8 promoter activity through activator protein-1 (AP-1) and nuclear transcription factor-kappa B (NF-κB) sites.

CONCLUSIONS

Our study proved that CXCL8 acted as an unfavorable factor promoting to tumor progression and poor prognosis of ADC, while DACH1 antagonized CXCL8 to provide a favorable survival of ADC patients. Double detection of DACH1 and CXCL8 may provide a precise information for further evaluating the prognosis of ADC patients.

IL-8 signaling is involved in resistance of lung carcinoma cells to erlotinib

A signaling pathway that is frequently deregulated in human carcinomas and has been explored as a therapeutic target involves the activation of the epidermal growth factor receptor (EGFR). Inhibition of EGFR via the small molecule inhibitors erlotinib and gefitinib commonly results in tumor resistance, even in patients with EGFR-mutant tumors that initially show substantial clinical responses. This study was designed to broaden our understanding of the molecular mechanisms of acquired resistance to erlotinib in lung cancer cells bearing wild type or mutated EGFR. We report here that generation of erlotinib-resistant lung cancer cells in vitro resulted in a phenotypic alteration reminiscent of an epithelial-mesenchymal transition (EMT) concomitant with a robust upregulation of the IL-8/IL-8R axis. Our results also demonstrate that upregulation of p38 MAPK signaling is responsible for the enhanced IL-8 secretion in the erlotinib-resistant tumor cells. Blockade of IL-8 signaling effectively reduced mesenchymal features of the resistant cells and also markedly enhanced their susceptibility to erlotinib. These results provide a rationale for the development of new therapeutic approaches involving blockade of IL-8 signaling for the management of acquired resistance to EGFR inhibition in patients with lung cancer.

The paradox of Th17 cell functions in tumor immunity

Immune system acts as a host defensive mechanism protecting against attacking pathogens and transformed cells, including cancer cells. Th17 cells are a specific subset of T helper lymphocytes determined by high secretion of IL-17 and other inflammatory cytokines. Th17 cells increase tumor progression by activating angiogenesis and immunosuppressive activities. They can also mediate antitumor immune responses through recruiting immune cells into tumors, stimulating effector CD8+ T cells, or surprisingly by altering toward Th1 phenotype and producing IFN-γ, so Th17 cells are supposed as a double-edged sword in cancer. A comprehensive approach to indicating the activity of Th17 cells in tumor progression could help in the planning of new therapeutic approaches specially targeting Th17 cells in cancer.

IL‑8 promotes proliferation and inhibition of apoptosis via STAT3/AKT/NF‑κB pathway in prostate cancer

Interleukin-8 (IL-8) possesses tumorigenic and proangiogenic properties, and is overexpressed in many human cancer types. However, only few studies have demonstrated the mechanisms of action of IL‑8 regarding the ability to promote proliferation and to inhibit apoptosis in prostate cancer. Here, the aim of the present study was to investigate the effects of IL‑8 on the prostate cancer cell line and determine possible mechanisms underlying its effect. In this study, IL‑8 was shown to be significantly upregulated in prostate cancer compared with paired normal control tissues. The data showed that IL‑8 exhibits direct oncogenicity, which significantly induced cell proliferation, invasion and attenuated apoptosis in prostate cancer cells via signal transducer and activator of transcription 3/protein kinase B/nuclear factor‑κB signaling pathways. In conclusion, modulation of IL‑8 expression or its associated signaling pathway may provide a novel working mechanism of IL‑8 in prostate cancer, and a promising strategy for controlling the progression and metastasis of prostate cancer.

Clinical significance of pretreatment serum levels of VEGF and its receptors, IL- 8, and their prognostic value in type I and II endometrial cancer patients

Objectives

The study aimed to assess the usefulness of the determination of cytokines: IL-8, VEGF and its soluble receptors: VEGF-R1, VEGF-R2 in patients with endometrial cancer (EC).

Material/Methods

The study group consisted of 118 patients with EC subjected to surgical treatment. Before the treatment we determined the serum levels of cytokines IL-8, and VEGF as well as VEGFR1 and VEGFR2 receptors. For comparison, the concentration of CA 125 was also measured. VEGFR1 and CA 125 were determined in the COBAS e601 system using Roche Diagnostics kits, while IL-8, VEGF and VEGFR2 were measured by ELISA assay using R&D Systems kits.

Results

The concentrations of IL-8, VEGF, VEGFR1 and CA 125 allowed to distinguish patients for the control group. The highest diagnostic sensitivity has been shown for the concentrations of VEGF (AUC = 0.904) and IL-8 (AUC = 0.818). Among all studied parameters only CA125 concentrations increased with the clinical stage; being significantly higher in patients in FIGO III-IV, than FIGO I-IB. In patients at the FIGO stage I-IB, complementary determinations of CA 125 and VEGF resulted in the largest increase of diagnostic sensitivity. Patients with metastases to the para-aortic lymph nodes had significantly higher levels of VEGF compared to subjects without such lesions. The concentrations of IL-8 were an independent prognostic factor in the assessment of overall survival in patients with type I endometrial cancer, while the concentrations of VEGFR2 in those with type II.

Conclusions

In patients with endometrial cancer, the clinical usefulness of IL-8 and VEGFR2 measurements as the potential prognostic factors has been demonstrated. In type I, the concentrations of IL-8 determined before treatment can be helpful in predicting overall survival. In patients qualified to type II EC, the concentrations of VEGFR2 have the value of an independent prognostic factor for overall survival, this requires research on larger groups of patients. The increased levels of VEGF may be useful in the preoperative assessment of the status of para-aortic lymph nodes.

The Inflammatory CXC Chemokines, GROαhigh, IP-10low, and MIGlow, in Tumor Microenvironment Can Be Used as New Indicators for Non-small Cell Lung Cancer Progression

AIMS

To investigate the clinical significance of tumor tissue-infiltrating chemokines expression in non-small cell lung cancer (NSCLC) microenvironment.

MATERIALS AND METHODS

Fresh tissue samples were acquired from 50 patients with NSCLC after operation. Then, we quantified the total protein with the BCA Protein Assay Kit and tested 13 chemotactic factors in paired samples including tumor tissues, tumor adjacent tissues, and normal tissues with the CBA Kit.

RESULTS

We found that the chemokine CC subfamily of MCP-1, MIP-1α, MIP-1β, and MIP-3α and the chemokine CXC subfamily of IL-8, GROα, IP-10, and MIG expressions in tumor tissues were significantly higher than those in tumor-adjacent tissues and normal tissues. However, regulated upon activation normal T cell expressed and secreted (RANTES), human thymus activation regulated chemokine (TARC), chemokine (C-C motif) ligand 11 (CCL11), interferon-inducible T cell alpha chemoattractant (I-TAC), and ENA-78 expressions did not show significant difference. Analyzing the influence of chemokine expression level in tumor tissues on disease progression, we found the median progression-free survival (mPFS) of patients with GROα^high was significantly lower than those with GROα^low; mPFS of patients with IP-10^low was significantly lower than those with IP-10^high; and mPFS of patients with MIG^low was significantly lower than those with MIG^high. However, MCP-1, MIP-1α, MIP-1β, MIP-3α, and IL-8 had no significant value to elevate the mPFS of patients with NSCLC.

CONCLUSION

In summary, tumor tissue-infiltrating CXC chemokines, GROα^high, IP-10^low, and MIG^low in the tumor microenvironment can be used as potential indicators for the progression of NSCLC.

Lipoteichoic acids from Staphylococcus aureus stimulate proliferation of human non-small-cell lung cancer cells in vitro

Pulmonary infections are frequent complications in lung cancer and may worsen its outcome and survival. Inflammatory mediators are suspected to promote tumor growth in non-small-cell lung cancer (NSCLC). Hence, bacterial pathogens may affect lung cancer growth by activation of inflammatory signalling. Against this background, we investigated the effect of purified lipoteichoic acids (LTA) of Staphylococcus aureus (S. aureus) on cellular proliferation and liberation of interleukin (IL)-8 in the NSCLC cell lines A549 and H226. A549 as well as H226 cells constitutively expressed TLR-2 mRNA. Even in low concentrations, LTA induced a prominent increase in cellular proliferation of A549 cells as quantified by automatic cell counting. In parallel, metabolic activity of A549 cells was enhanced. The increase in proliferation was accompanied by an increase in IL-8 mRNA expression and a dose- and time-dependent release of IL-8. Cellular proliferation as well as the release of IL-8 was dependent on specific ligation of TLR-2. Interestingly, targeting IL-8 by neutralizing antibodies completely abolished the LTA-induced proliferation of A549 cells. The pro-proliferative effect of LTA could also be reproduced in the squamous NSCLC cell line H226. In summary, LTA of S. aureus induced proliferation of NSCLC cell lines of adeno- and squamous cell carcinoma origin. Ligation of TLR-2 followed by auto- or paracrine signalling by endogenously synthesized IL-8 is centrally involved in LTA-induced tumor cell proliferation. Therefore, pulmonary infections may exert a direct pro-proliferative effect on lung cancer growth.

IL-17 Promotes Angiogenic Factors IL-6, IL-8, and Vegf Production via Stat1 in Lung Adenocarcinoma

Inflammation and angiogenesis are two hallmarks of carcinoma. The proinflammatory cytokine interleukin-17 (IL-17) facilitates angiogenesis in lung cancer; however, the underlying mechanism is not fully understood. In this study, tumour microvessel density (MVD) was positively associated with IL-17, interleukin-6 (IL-6), interleukin-8 (IL-8), and vascular endothelial cell growth factor (VEGF) expression in human lung adenocarcinoma tissues, and it was increased in tumour tissues of A549-IL-17 cell-bearing nude mice. Importantly, positive correlations were also detected between IL-17 expression and IL-6, IL-8 and VEGF expression in human lung adenocarcinoma tissues. Furthermore, IL-6, IL-8 and VEGF production, as well as STAT1 phosphorylation, were increased in tumour tissues of A549-IL-17 cell-bearing nude mice in vivo and in A549 and H292 cells following IL-17 stimulation in vitro. In addition, STAT1 knockdown using an inhibitor and siRNA attenuated the IL-17-mediated increases in IL-6, IL-8 and VEGF expression in A549 and H292 cells. In conclusion, IL-17 may promote the production of the angiogenic inducers IL-6, IL-8 and VEGF via STAT1 signalling in lung adenocarcinoma.

Physico-chemical properties and biological effects of diesel and biomass particles

Diesel combustion and solid biomass burning are the major sources of ultrafine particles (UFP) in urbanized areas. Cardiovascular and pulmonary diseases, including lung cancer, are possible outcomes of combustion particles exposure, but differences in particles properties seem to influence their biological effects. Here the physico-chemical properties and biological effects of diesel and biomass particles, produced under controlled laboratory conditions, have been characterized. Diesel UFP were sampled from a Euro 4 light duty vehicle without DPF fuelled by commercial diesel and run over a chassis dyno. Biomass UFP were collected from a modern automatic 25 kW boiler propelled by prime quality spruce pellet. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of both diesel and biomass samples showed aggregates of soot particles, but in biomass samples ash particles were also present. Chemical characterization showed that metals and PAHs total content was higher in diesel samples compared to biomass ones. Human bronchial epithelial (HBEC3) cells were exposed to particles for up to 2 weeks. Changes in the expression of genes involved in xenobiotic metabolism were observed after exposure to both UFP already after 24 h. However, only diesel particles modulated the expression of genes involved in inflammation, oxidative stress and epithelial-to-mesenchymal transition (EMT), increased the release of inflammatory mediators and caused phenotypical alterations, mostly after two weeks of exposure. These results show that diesel UFP affected cellular processes involved in lung and cardiovascular diseases and cancer. Biomass particles exerted low biological activity compared to diesel UFP. This evidence emphasizes that the study of different emission sources contribution to ambient PM toxicity may have a fundamental role in the development of more effective strategies for air quality improvement.

CXCR1/2 antagonism with CXCL8/Interleukin-8 analogue CXCL8(3-72)K11R/G31P restricts lung cancer growth by inhibiting tumor cell proliferation and suppressing angiogenesis

CXCR1 and CXCR2 together with cognate chemokines are significantly upregulated in a number of cancers, where they act as key regulators of tumor cell proliferation, metastasis, and angiogenesis. We have previously reported a mutant protein of CXCL8/Interleukin-8, CXCL8_(3–72)K11R/G31P (G31P), which can act as a selective antagonist towards CXCR1/2 with therapeutic efficacy in both inflammatory diseases and malignancies. In this study, we investigated the effect of this ELR-CXC chemokine antagonist G31P on human non-small cell lung cancer cells and lung tumor progression in an orthotopic xenograft model. We report increased mRNA levels of CXCR1 and CXCR2 in human lung cancer tissues compared to normal counterparts. Expression levels of CXCR1/2 cognate ligands was determined by ELISA. CXCR1/2 receptor antagonism via G31P leads to decreased H460 and A549 cell proliferation and migration in a dose-dependent manner. G31P also enhanced apoptosis in lung cancer cells as determined by elevated levels of cleaved PARP, Caspase-8, and Bax, together with a reduced expression of the anti-apoptotic protein Bcl-2. In an in vivo orthotopic xenograft mouse model of human lung cancer, G31P treatment suppressed tumor growth, metastasis, and angiogenesis. At the molecular level, G31P treatment was correlated with decreased expression of VEGF and NFкB-p65, in addition to reduced phosphorylation of ERK1/2 and AKT. Our results suggest that G31P blockage of CXCR1 and CXCR2 can inhibit human lung cancer cell growth and metastasis, which offers potential therapeutic opportunities.

Genetic polymorphism rs3760396 of the chemokine (C-C motif) ligand 2 gene (CCL2) associated with the susceptibility of lung cancer in a pathological subtype-specific manner in Han-ancestry Chinese: a case control study

Background

Chemokines are well known inflammatory factors critical for tumor development in diverse tissues, including lung cancer. Chemokine (C-C motif) Ligand 2 (CCL2) was one of such chemokines important for both primary tumor development and metastasis of various cancers. Polymorphism at rs3760396 of CCL2 genes is associated with the prognosis of non-small cell lung cancer (NSCLC). The goal of our study was to examine the relationship of genetic polymorphisms rs3760396 with the susceptibility of lung cancer and its pathological subtypes in Han-ancestry Chinese population.

Methods

rs3760396 G/C polymorphism of CCL2 was genotyped using PCR in 394 patients with lung cancer and 545 cancer-free controls from the same Northeast region of China.

Results

After controlling for gender, age and smoking status, no significant association was observed between rs3760396 polymorphism and overall lung cancer. However, minor allele G of rs3760396 polymorphism was significantly associated with increased risk of adenosquamous lung carcinoma with either allelic genetic model (OR = 5.29, P < 0.001), or dominant genetic model (OR = 9.88, P < 0.001), or genotypic model (GC genotype vs. CC genotype, OR = 10.73, P < 0.001). Although rs3760396 polymorphism was not significantly associated with increased risk of adenocarcinoma subtype, it was nominally associated with the pooled outcome of either adenocarcinoma or adenosquamous carcinoma under allelic genetic model (OR = 1.54, P = 0.023) or dominant genetic model (OR = 1.57, P = 0.031).

Conclusions

Our study suggested rs3760396 polymorphism of CCL2 is associated not only with prognosis of NSCLC, but also with risk of lung cancer in a subtype-specific manner. Our results further supported previous evidence of the important role of CCL2 in lung cancer development.

IL-8 as mediator in the microenvironment-leukaemia network in acute myeloid leukaemia

The bone marrow microenvironment is physiologically hypoxic with areas being as low as 1% O2, e.g. the stem cell niche. Acute myeloid leukaemia (AML) blasts misuse these bone marrow niches for protection by the local microenvironment, but also might create their own microenvironment. Here we identify IL-8 as a hypoxia-regulated cytokine in both AML cell lines and primary AML samples that is induced within 48 hours of severe hypoxia (1% O2). IL-8 lacked effects on AML cells but induced migration in mesenchymal stromal cells (MSC), an integral part of the bone marrow. Accordingly, MSC were significantly increased in AML bone marrow as compared to healthy bone marrow. Interestingly, mononuclear cells obtained from healthy bone marrow displayed both significantly lower endogenous and hypoxia-induced production of IL-8. IL-8 mRNA expression in AML blasts from 533 patients differed between genetic subgroups with significantly lower expression of IL-8 in acute promyelocytic leukaemia (APL), while in non APL-AML patients with FLT ITD had the highest IL-8 expression. In this subgroup, high IL-8 expression was also prognostically unfavourable. In conclusion, hypoxia as encountered in the bone marrow specifically increases IL-8 expression of AML, which in turn impacts niche formation. High IL-8 expression might be correlated with poor prognosis in certain AML subsets.

Role of Chemokines in Non-Small Cell Lung Cancer: Angiogenesis and Inflammation

Non-small cell lung cancer (NSCLC) is one of the most common types of aggressive cancer. The tumor tissue, which shows an active angiogenesis, is composed of neoplastic and stromal cells, and an abundant inflammatory infiltrate. Angiogenesis is important to support tumor growth, while infiltrating cells contribute to the tumor microenvironment through the secretion of growth factors, cytokines and chemokines, important molecules in the progression of the disease. Chemokines are important in development, activation of the immune response, and physiological angiogenesis. Chemokines have emerged as important regulators in the pathophysiology of cancer. These molecules are involved in the angiogenesis/angiostasis balance and in the recruitment of tumor infiltrating hematopoietic cells. In addition, chemokines promote tumor cell survival, as well as the directing and establishment of tumor cells to metastasis sites. The findings summarized here emphasize the central role of chemokines as modulators of tumor angiogenesis and their potential role as therapeutic targets in the inflammatory process of NSCLC angiogenesis.

Association of chemokine and chemokine receptor expression with the invasion and metastasis of lung carcinoma

The chemokine system has been reported to be utilized and manipulated by tumor cells in order to promote local tumor growth and distant dissemination. The present study aimed to investigate the expression of three chemokine ligand-receptor axes in lung carcinoma tissues. Tumor and healthy normal tissue samples were obtained from 120 lung carcinoma patients following surgical resection. Immunohistochemistry and reverse transcription quantitative polymerase chain reaction were used in order to identify the protein and messenger (m)RNA expression of chemokines, including chemokine (C-X-C motif) ligand (CXCL)12/stromal cell-derived factor (SDF)-1, CXCL8/interleukin (IL)-8, chemokine (C-C motif) ligand (CCL)19 and CCL21, and the corresponding chemokine receptors, chemokine (C-X-C motif) receptor (CXCR)4, CXCR1, CXCR2 and chemokine (C-C motif) receptor (CCR)7, respectively. The results revealed that compared with the normal lung tissues, lung carcinoma tissues expressed significantly higher mRNA levels of CXCL12/SDF-1, CXCR4, CXCL8/IL-8, CXCR2, CCL19 and CCR7 (P<0.01). In four histological subtypes, adenocarcinoma presented dominant expression of CXCR4, CXCR2, CXCL8/IL-8 and CCL19 (P<0.05). In addition, it was demonstrated that tumor staging was inversely correlated with chemokine receptor CCR7 and CXCR2 mRNA expression as well as positively correlated with CXCL12/SDF-1, CXCL8/IL-8 and CCL19 mRNA levels (P<0.05). Lymph node metastasis presented a positive correlation with CXCR4, CXCR2 and CXCL8/IL-8 expression and a negative correlation with CCL19 and CCR7 expression (P<0.05). Furthermore, vascular invasion was more prevalent in patients with higher expression levels of CXCR4, CCR7 or CCL19 (P<0.01). In conclusion, these data suggested that the ligand-receptor interaction of CXCL8-CXCR2, CXCL12-CXCR4 and CCL19-CCR7 may be involved in the tumorigenesis of lung carcinoma. Higher expression levels of chemokines and lower expression of chemokine receptors indicated poor tumor staging. The CXC chemokine receptors, CXCR4 and CXCR2, promoted lymphatic metastasis through the activation of their specific ligands, while CCL19 and its receptor CCR7 had an essential role in hematogenous metastasis of lung carcinoma.

Interleukin-8 promotes cell migration through integrin αvβ6 upregulation in colorectal cancer

Colorectal cancer (CRC), which is notorious for high morbidity and mortality around the world, shows a predilection for metastasis to liver. Interleukin-8 (IL-8), a chemokine with a defining CXC amino acid motif, has been reported to promote CRC cell migration and is associated with poor prognosis of CRC. However, the underlying molecular mechanism of IL-8-mediated migration remains obscure. In this study, we first demonstrated the cross talk between IL-8 and integrin αvβ6. We analyzed 139 human CRC samples, and found that the immunohistochemical expression of αvβ6 was significantly correlated with expression of IL-8. Furthermore, IL-8 increased the migration through integrin αvβ6 in human CRC cells, and both CXCR1 and CXCR2 were primarily involved during the process. IL-8 upregulated αvβ6 expression in a dose-dependent manner through activation of ERK and Ets-1 signaling pathway. Taken together, our results indicated that IL-8 enhances the migration of CRC cells by increasing αvβ6 integrin expression through the ERK/Ets-1 pathway. Targeting integrin αvβ6 in IL-8 expressing tumors might be a potential therapeutic strategy for CRC patients.

AhR and Arnt differentially regulate NF-κB signaling and chemokine responses in human bronchial epithelial cells

Background

The aryl hydrocarbon receptor (AhR) has gradually emerged as a regulator of inflammation in the lung and other tissues. AhR may interact with the p65-subunit of the nuclear factor (NF)-κB transcription factors, but reported outcomes of AhR/NF-κB-interactions are conflicting. Some studies suggest that AhR possess pro-inflammatory activities while others suggest that AhR may be anti-inflammatory. The present study explored the impact of AhR and its binding partner AhR nuclear translocator (Arnt) on p65-activation and two differentially regulated chemokines, CXCL8 (IL-8) and CCL5 (RANTES), in human bronchial epithelial cells (BEAS-2B).

Results

Cells were exposed to CXCL8- and CCL5-inducing chemicals, 1-nitropyrene (1-NP) and 1-aminopyrene (1-AP) respectively, or the synthetic double-stranded RNA analogue, polyinosinic-polycytidylic acid (Poly I:C) which induced both chemokines. Only CXCL8, and not CCL5, appeared to be p65-dependent. Yet, constitutively active unligated AhR suppressed both CXCL8 and CCL5, as shown by siRNA knock-down and the AhR antagonist α-naphthoflavone. Moreover, AhR suppressed activation of p65 by TNF-α and Poly I:C as assessed by luciferase-assay and p65-phosphorylation at serine 536, without affecting basal p65-activity. In contrast, Arnt suppressed only CXCL8, but did not prevent the p65-activation directly. However, Arnt suppressed expression of the NF-κB-subunit RelB which is under transcriptional regulation by p65. Furthermore, AhR-ligands alone at high concentrations induced a moderate CXCL8-response, without affecting CCL5, but suppressed both CXCL8 and CCL5-responses by Poly I:C.

Conclusion

AhR and Arnt may differentially and independently regulate chemokine-responses induced by both inhaled pollutants and pulmonary infections. Constitutively active, unligated AhR suppressed the activation of p65, while Arnt may possibly interfere with the action of activated p65. Moreover, ligand-activated AhR suppressed CXCL8 and CCL5 responses by other agents, but AhR ligands alone induced CXCL8 responses when given at sufficiently high concentrations, thus underscoring the duality of AhR in regulation of inflammation. We propose that AhR-signaling may be a weak activator of p65-signaling that suppresses p65-activity induced by strong activators of NF-κB, but that its anti-inflammatory properties also are due to interference with additional pathways.

Clinicopathological and prognostic significance of interleukin-8 expression and its relationship to KRAS mutation in lung adenocarcinoma

Background:

On the basis of our recent findings of oncogenic KRAS-induced interleukin-8 (IL-8) overexpression in non-small cell lung cancer, we assessed the clinicopathological and prognostic significances of IL-8 expression and its relationship to KRAS mutations in lung adenocarcinomas.

Methods:

IL-8 expression was examined by quantitative RT–PCR using 136 of surgical specimens from lung adenocarcinoma patients. The association between IL-8 expression, clinicopathological features, KRAS or EGFR mutation status and survival was analysed.

Results:

IL-8 was highly expressed in tumours from elderly patients or smokers and in tumours with pleural involvement or vascular invasion. In a non-smokers' subgroup, IL-8 level positively correlated with age. IL-8 was highly expressed in tumours with KRAS mutations compared with those with EGFR mutations or wild-type EGFR/KRAS. Lung adenocarcinoma patients with high IL-8 showed significantly shorter disease-free survival (DFS) and overall survival (OS) than those with low IL8. DFS and OS were significantly shorter in the patients with mutant KRAS/high IL-8 than in those with wild-type KRAS/low IL-8. Cox regression analyses demonstrated that elevated IL-8 expression correlated with unfavourable prognosis.

Conclusions:

Our findings suggest that IL-8 expression is associated with certain clinicopathological features including age and is a potent prognostic marker in lung adenocarcinoma, especially in oncogenic KRAS-driven adenocarcinoma.

Analysis of LPS-induced, NFκB-dependent interleukin-8 transcription in kidney embryonic cell line expressing TLR4 using luciferase assay

Gene expression is orchestrated by a complex network of signal transduction pathways that typically originate on cell surface receptors and culminate in DNA-binding transcription factors, which translocate to the nucleus and bind cis-regulatory elements in promoter regions of genes, thereby inducing de novo synthesis of the nascent RNA transcripts and their splicing. Gene expression arrays monitor abundance of the matured, spliced cDNA, which undergoes additional posttranscriptional modifications that greatly affect the half-life of the cDNA. Thus, the relative abundance of cDNA is not necessarily commensurable with the activity of promoters of the corresponding genes. In contrast, reporter gene assays provide valuable insight into the regulation of gene expression at the level of transcription and allow for discerning the contribution of individual transcription factors into changes in gene expression. Here, we describe a robust reporter gene assay method that is useful for exploration of transcription regulatory network, which regulates gene expression in response to inflammation. The method is exemplified by using the promoter region of the prototypic pro-inflammatory chemokine interleukin-8 (IL-8, CXCL8), which plays an important role in immune response as well as carcinogenesis. Using the luciferase reporter gene assay, we analyze the activation status of the IL-8 promoter in lipopolysaccharide (LPS)-stimulated human embryonic kidney cells.

Physiological and pathological angiogenesis in the adult pulmonary circulation

Angiogenesis occurs during growth and physiological adaptation in many systemic organs, for example, exercise-induced skeletal and cardiac muscle hypertrophy, ovulation, and tissue repair. Disordered angiogenesis contributes to chronic inflammatory disease processes and to tumor growth and metastasis. Although it was previously thought that the adult pulmonary circulation was incapable of supporting new vessel growth, over that past 10 years new data have shown that angiogenesis within this circulation occurs both during physiological adaptive processes and as part of the pathogenic mechanisms of lung diseases. Here we review the expression of vascular growth factors in the adult lung, their essential role in pulmonary vascular homeostasis and the changes in their expression that occur in response to physiological challenges and in disease. We consider the evidence for adaptive neovascularization in the pulmonary circulation in response to alveolar hypoxia and during lung growth following pneumonectomy in the adult lung. In addition, we review the role of disordered angiogenesis in specific lung diseases including idiopathic pulmonary fibrosis, acute adult distress syndrome and both primary and metastatic tumors of the lung. Finally, we examine recent experimental data showing that therapeutic enhancement of pulmonary angiogenesis has the potential to treat lung diseases characterized by vessel loss.

Rationale and Means to Target Pro-Inflammatory Interleukin-8 (CXCL8) Signaling in Cancer

It is well established that chronic inflammation underpins the development of a number of human cancers, with pro-inflammatory signaling within the tumor microenvironment contributing to tumor progression and metastasis. CXCL8 is an ELR⁺ pro-inflammatory CXC-chemokine which mediates its effects via signaling through two G protein-coupled receptors, CXCR1 and CXCR2. Elevated CXCL8-CXCR1/2 signaling within the tumor microenvironment of numerous cancers is known to enhance tumor progression via activation of signaling pathways promoting proliferation, angiogenesis, migration, invasion and cell survival. This review provides an overview of established roles of CXCL8-CXCR1/2 signaling in cancer and subsequently, discusses the possible strategies of targeting CXCL8-CXCR1/2 signaling in cancer, covering indirect strategies (e.g., anti-inflammatories, NFκB inhibitors) and direct CXCL8 or CXCR1/2 inhibition (e.g., neutralizing antibodies, small molecule receptor antagonists, pepducin inhibitors and siRNA strategies). Reports of pre-clinical cancer studies and clinical trials using CXCL8-CXCR1/2-targeting strategies for the treatment of inflammatory diseases will be discussed. The future translational opportunities for use of such agents in oncology will be discussed, with emphasis on exploitation in stratified populations.

Expression of Brachyury gene is a significant prognostic factor for primary lung carcinoma

BACKGROUND

The clinical significance of Brachyury expression and its relationship to epithelial-mesenchymal transition in primary lung carcinoma is unclear.

METHODS

Expression of Brachyury mRNA was investigated in 104 surgically resected primary lung carcinoma tissues. Immunohistochemical analysis of Brachyury transcription factor, Slug, E-cadherin, IL-8, N-cadherin, and Ki67 was performed in 67 of 104 cases, and their expression was correlated to prognoses and clinicopathological factors.

RESULTS

Brachyury mRNA expression in primary lung carcinoma tissues was a significant predictor of poor prognosis for 5-year disease-free survival and overall survival rates and was significantly correlated to vascular invasion, lymphatic permeation, histological grade, pathologic T stage, and pathologic N stage (P < 0.05). Brachyury mRNA expression was significantly inversely correlated to E-cadherin expression (P = 0.0252) and positively correlated to IL-8 protein (P = 0.0241) and to Slug protein (P = 0.0243) in adenocarcinoma tissues.

CONCLUSIONS

A positive association between Brachyury and Slug and IL-8, and a negative association with E-cadherin may lead to invasiveness and metastasis in primary lung carcinoma. Brachyury mRNA expression is a significant predictor of poor prognosis in primary lung carcinoma.

Human papillomavirus up-regulates MMP-2 and MMP-9 expression and activity by inducing interleukin-8 in lung adenocarcinomas

Human papillomavirus (HPV) infection is associated with non-smoking female lung cancer. Our previous report demonstrated that HPV 16 promotes lung tumor cell progression by up-regulating interleukin-17 (IL-17). IL-17 and its downstream signaling mediator, interleukin-8 (IL-8), have been implicated to modulate a variety of pro-angiogenic factors and play important roles in tumor angiogenesis and metastasis. Accordingly, we hypothesized that HPV infection may potentiate tumorigenic and metastatic characteristics of the infected cells through IL-8. The goal of the present study was to determine whether HPV infection in lung adenocarcinoma cells can promote the expression of IL-8 and metalloproteinases (MMPs) to make the transformed cells equipped with angiogenic and metastatic characteristics. The expression of IL-8 and MMPs in HPV 16 E6-transfected H1299 cells was analyzed to examine the hypothesis. HPV 16 E6 up-regulates pro-angiogenic MMP-2 and MMP-9 through inducing IL-8 expression in lung cancer cells. The results indicate that, in addition to cell proliferation-related machinery, HPV infection promotes the expression and activities of angiogenic and metastatic molecules in lung adenocarcinoma cells. The cytokines induced by HPV infection may work together to confer the malignant and tumorigenic potentials on the infected cells by promoting machineries of growth, angiogenic and metastatic characteristics.

As an independent unfavorable prognostic factor, IL-8 promotes metastasis of nasopharyngeal carcinoma through induction of epithelial-mesenchymal transition and activation of AKT signaling

Nasopharyngeal carcinoma (NPC) has the highest metastatic potential among head and neck cancers. Distant metastasis is the major cause of treatment failure. The role of interleukin-8 (IL-8) in NPC progression remains unknown. Our multivariate survival analyses of 255 patients with NPC revealed that higher IL-8 expression in primary NPC tissue was an independent prognostic factor for overall survival, disease-free survival, and distant metastasis-free survival of the patients. In vitro study revealed that IL-8 was highly expressed in the established high-metastasis NPC clone S18 relative to the low-metastasis cells. Suppression of IL-8 by short-hairpin RNA reduced the expression of IL-8 in S18 cells and subsequently inhibited migration, invasion, and hepatic metastasis of the cells without influencing cellular growth. Overexpression of IL-8 in S26 cells resulted in increased migration, invasion, and metastasis capabilities of the cells without affecting cellular growth. Exogenous IL-8 enhanced the migration and invasion of low-metastasis CNE-2 cells in a dose-dependent manner. An epithelial–mesenchymal transition (EMT) could be induced by IL-8 in various NPC cell lines. The high level of phosphorylated AKT in S18 cells could be suppressed by knocking down IL-8 expression. Further, IL-8-promoted migration and invasion could be abolished by either the application of the phosphoinositide-3-kinase inhibitor LY294002 or the knock down of AKT expression by using small-interfering RNA. In summary, IL-8 serves as an independent prognostic indicator of overall survival, disease-free survival, and metastasis-free survival for patients with NPC. IL-8 promotes NPC metastasis via autocrine and paracrine means, involving activation of AKT signaling and inducing EMT in NPC cells.