Combined effects of IL-8 and CXCR2 gene polymorphisms on breast cancer susceptibility and aggressiveness

IL-8 promotes lens capsular residual cells migration by down-regulates expression of E-cadherin and ZO-1 via the CXCR1/2-NF-κB-RhoA signal pathway

BACKGROUND

Posterior capsular opacification is a major complication following cataract surgery, marked by proliferation, migration, epithelial-mesenchymal transition, and fibrosis of residual epithelial cells. Various inflammatory cytokines are upregulated and contribute to the development of posterior capsular opacification. The effect of interleukin-8 on residual epithelial cells has not been fully determined.

METHODS

Aqueous humor and anterior capsules samples were collected from cataract surgery. Capsular bags from rats and pigs were cultured in DMEM media. Protein and mRNA expressions were measured using immunoblot and qPCR. Cell migration was assessed using the transwell assay.

RESULTS

Interleukin-8 is an early inflammatory factor secreted by residual lens epithelial cells. Migration of lens epithelial cells in aqueous humor positively correlates with interleukin-8 levels, and this effect is inhibited by the receptors of interleukin-8 CXCR1/2 blocker Reparaxin. The expression of tight-junction protein ZO-1 and cell-adhesion protein E-cadherin were down-regulated by administrating interleukin-8, and cell migration of both SRA01/04 cell line in vitro and capsular residual epithelial cells ex vivo were up-regulated via activating RhoA expression and RhoA/GTPase activity. The loss-of- function studies demonstrate that interleukin-8 binding to its receptor CXCR1/2 activates NF-κB/p65, which then turns on the RhoA's expression and RhoA/GTPase activity, and RhoA-modulated the downexpression of E-cadherin and ZO-1 and the increase of cell migration.

CONCLUSIONS

The upregulation in interleukin-8 occurs early in posterior capsular opacification and contributes to down-regulating tight-junctions among epithelial cells and elevates cell migration via the CXCR1/2-NF-κB-RhoA signaling pathway. These demonstrated that interleukin-8 could be a potential target for preventing posterior capsular opacification.

Clinical significance of the CXCL8/CXCR1/R2 signalling axis in patients with invasive breast cancer

The C-X-C motif chemokine ligand 8 (CXCL8)-C-X-C chemokine receptor (CXCR)1/2 signalling axis is among numerous mechanisms which stimulate the immune system to defend against tumour growth and influence the tumour microenvironment to promote tumour growth. This pathway plays an important role in the development of a number of cancers including breast cancer (BC). The aim of the present study was to analyse the levels of the chemokine CXCL8 and its receptors, CXCR1 and CXCR2, in the serum of female patients with invasive BC and to assess the expression of these parameters at the mRNA level, considering molecular subtypes and degrees of cancer malignancy. The study group consisted of 62 patients with histopathologically confirmed invasive BC. The control group consisted of 18 patients with histopathologically confirmed fibroadenoma, a benign breast tumour. The levels of CXCL8, CXCR1 and CXCR2 were determined by sandwich ELISA using the CLOUD-CLONE ELISA kit. CXCL8, CXCR1 and CXCR2 transcript levels were analysed using reverse transcription-quantitative PCR. Results showed that serum CXCL8 levels in female patients with invasive BC were significantly higher compared with those in the control group (P<0.05). In addition, significantly elevated CXCR1 levels were observed in luminal B human epidermal growth factor receptor 2+ carcinoma compared with those in the control group. Analysis of CXCL8 in the serum of female patients with BC showed a statistically significant difference between clinical stage G1 and G2 (P<0.05), G2 and G3 (P<0.01), and G1 and G3 (P<0.0001). On the other hand, the analysis of CXCR1 and CXCR2 levels in the serum of the patients revealed a statistically significant difference between G2 and G3 (P<0.05). The current study showed that abnormalities in the immune response involving the CXCL8-CXCR1/2 signalling axis in patients with invasive BC are involved in the development of these tumours. Moreover, the demonstrated severity of changes occurring at protein level may suggest the potential usefulness of their determination as potential diagnostic markers in the clinic.

Meta-analyses of the relationship between five CXCL8 gene polymorphisms and overall cancer risk, and a case-control study of oral cancer

BACKGROUND

C-X-C motif chemokine ligand (CXCL8), also known as interleukin-8, is a prototypical CXC family chemokine bearing a glutamic acid-leucine-arginine (ELR) motif that plays key roles in the onset and progression of a range of cancers in humans. Many prior studies have focused on exploring the relationship between CXCL8 gene polymorphisms and the risk of cancer. However, the statistical power of many of these reports was limited, yielding ambiguous or conflicting results in many cases.

METHODS

Accordingly, the PubMed, Wanfang, Scopus and Web of Science databases were searched for articles published until July 20, 2023 using the keywords 'IL-8' or 'interleukin-8' or 'CXCL8', 'polymorphism' and 'cancer' or 'tumor'. Odds ratios (ORs) and 95% confidence intervals (CIs) were utilized to examine the association. The CXCL8 +781 polymorphism genotypes were assessed with a TaqMan assay.

RESULTS

About 29 related publications was conducted in an effort to better understand the association between these polymorphisms and disease risk. The CXCL8 -353A/T polymorphism was associated with an increased overall cancer risk [A vs. T, odds ratio (OR) = 1.255, 95% confidence interval (CI) (1.079-1.459), Pheterogeneity = 0.449, P = 0.003]. The CXCL8 +781 T/C allele was similarly associated with a higher risk of cancer among Caucasians [TT vs. TC + CC, OR = 1.320, 95%CI (1.046-1.666), Pheterogeneity = 0.375, P = 0.019]. Furthermore, oral cancer patients carrying the CXCL8 +781 TT + TC genotypes exhibited pronounced increases in serum levels of CXCL8 as compared to the CC genotype (P < 0.01), and also shown similar trend as compared to genotype-matched normal controls (P < 0.01). Finally, several limitations, such as the potential for publication bias or heterogeneity among the included studies should be paid attention.

CONCLUSION

Current study suggested that the CXCL8 -353 and +781 polymorphisms may be associated with a greater risk of cancer, which might impact cancer prevention, diagnosis, or treatment through the different expression of CXCL8. At the same time, the +781 polymorphism may further offer value as a biomarker that can aid in the early identification and prognostic evaluation of oral cancer.

Association of Four Interleukin-8 Polymorphisms (-251 A>T, +781 C>T, +1633 C>T, +2767 A>T) with Ovarian Cancer Risk: Focus on Menopausal Status and Endometriosis-Related Subtypes

Interleukin-8 (IL-8) is involved in the regulation of inflammatory processes and carcinogenesis. Single-nucleotide polymorphisms (SNPs) within the IL-8 gene have been shown to alter the risks of lung, gastric, or hepatocellular carcinomas. To date, only one study examined the role of IL-8 SNPs in ovarian cancer (OC), suggesting an association between two IL-8 SNPs and OC risk. In this study, we investigated four common IL-8 SNPs, rs4073 (-251 A>T), rs2227306 (+781 C>T), rs2227543 (+1633 C>T), and rs1126647 (+2767 A>T), using the restriction fragment length polymorphism (PCR-RFLP) technique. Our study included a cohort of 413 women of Central European descent, consisting of 200 OC patients and 213 healthy controls. The most common (73.5%) histological type was high-grade serous OC (HGSOC), whereas 28/200 (14%) patients had endometriosis-related (clear cell or endometrioid) OC subtypes (EROC). In postmenopausal women, three of the four investigated SNPs, rs4073 (-251 A>T), rs2227306 (+781 C>T), and rs2227543 (+1633 C>T), were associated with OC risk. Furthermore, we are the first to report a significant relationship between the T allele or TT genotype of SNP rs1126647 (+2767 A>T) and the EROC subtype (p = 0.02 in the co-dominant model). The TT homozygotes were found more than twice as often in EROC compared to other OC subtypes (39% vs. 19%, p = 0.015). None of the examined SNPs appeared to influence OC risk in premenopausal women, nor were they associated with the aggressive HGSOC subtype or the stage of disease at the initial diagnosis.

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.

CLDN6 inhibits breast cancer cell malignant behavior by suppressing ERK signaling

Claudin 6 (CLDN6) is an important component of tight junctions. Through the PDZ binding motif, CLDN6 binds to a variety of signaling proteins that contain the PDZ domain to regulate different signaling pathways, and plays an important role in the occurrence and development of tumors. Our previous work showed that CLDN6 was expressed at low levels in breast cancer cells, and overexpression of CLDN6 inhibited breast cancer cell proliferation, migration and invasion. However, the mechanism of how CLDN6 works remains unclear. In this study, we aimed to explore the mechanism by which CLDN6 inhibits breast cancer cell malignant behavior. As a result, overexpression of CLDN6 inhibited the proliferation of breast cancer cells along with the downregulation of cyclin D1, which plays an important role in regulating cell proliferation. After overexpression of Sp1 in CLDN6-overexpressing cells, the expression of cyclin D1 was upregulated. On the other hand, CLDN6 inhibited breast cancer cell migration and invasion along with the downregulation of IL-8, CXCR2 and FAK. When treated with IL-8, the migration and invasion ability were promoted along with the upregulation of CXCR2 and p-FAK, and the cytoskeleton was rearranged in CLDN6-overexpressing cells. Furthermore, when treated with the ERK signaling activator PMA, the proliferation, migration and invasion abilities were promoted along with the upregulation of Sp1, cyclin D1 and IL-8 in CLDN6-overexpressin cells. In conclusion, CLDN6 suppressed ERK/Sp1/cyclin D1 and ERK/IL-8 signaling to inhibit proliferation, migration and invasion in breast cancer cells. The mechanism may provide experimental evidence for the treatment of breast cancer targeting CLDN6.

Association between IL8RB C1208T mutation and risk of cancer: A pooled analysis based on 5299 cases and 6899 controls

INTRODUCTION

The CXC chemokines are unique cytokines that play a vital role in the progression of many cancers. Association between chemokine (C-X-C motif) receptor 2 (IL8RB) C1208T mutation and cancer risk remains incomprehensive.

METHODS

We therefore utilized odds ratios and in silico analysis to explore the relationship of IL8RB polymorphism on risk to cancer. Furthermore, we adopted gene set enrichment analysis to investigate the IL8RB expression in prostate adenocarcinoma.

RESULTS

A total of 14 case-control studies combined with 5299 cases and 6899 controls were included in our analysis. We revealed that individuals carrying TT genotype had an 14% increased cancer risk compared with those with TC + colon cancer (CC) genotype (odds ratio [OR] = 1.14, 95% CI = 1.05-1.25, P = .003, I2 = 35.6). Stratification analysis by race showed that East Asians with TT + TC genotype may have a 25% decreased cancer risk compared with control. Stratification analysis by cancer type revealed that individuals with TT genotype were associated with elevated risk of urinary cancer than control. The expression of IL8RB was attenuated in prostate adenocarcinoma.

CONCLUSIONS

IL8RB C1208T may be correlated with the risk of cancer, especially prostate adenocarcinoma.

Impacts of Chemokine (C-X-C Motif) Receptor 2 C1208T Polymorphism on Cancer Susceptibility

Background

The CXC chemokines belong to a unique family of cytokines that participates in the progression and development of many malignant tumors. Evidence for the relationship between chemokine (C-X-C motif) receptor 2 (CXCR2) C1208T polymorphism and susceptibility to cancer remains inconsistent.

Methods

Odds ratios (ORs), 95% confidence intervals (CIs), and combined analysis were used to investigate the effect of CXCR2 variation on cancer risk. Gene Set Enrichment Analysis (GSEA) and enzyme-linked immunosorbent assay (ELISA) were also used to evaluate the expression of CXCR2 in prostate cancer (PCA).

Results

Across 11 case-control studies, 4,909 cases and 5,884 controls were involved in the current analysis. Individuals with a TT genotype were associated with increased risk of digestive cancer, compared to those with a TC+CC genotype (OR = 1.16, 95%CI = 1.02-1.31, P = 0.025). Individuals carrying the TT genotype had a 39% higher risk of urinary cancer than those carrying CC genotype (OR = 1.39, 95%CI = 1.04-1.87, P = 0.025). Individuals with a TT genotype showed a 56% augmented breast cancer risk, compared to those with a CC genotype (OR = 1.56, 95%CI = 1.03-2.35, P = 0.034). It was found that CXCR2 expression was downregulated in PCA. Compared with PCA subjects carrying the CC genotype, the expression of CXCR2 was decreased in patients with the TT genotype.

Conclusions

The CXCR2 C1208T variation was associated with elevated risk of urinary, breast, and digestive cancer. However, the C1208T polymorphism was correlated with attenuated risk of lung cancer.

An updated review on the role of the CXCL8-CXCR1/2 axis in the progression and metastasis of breast cancer

Chronic inflammation is a major factor in tumor growth and progression. Cancer cells secrete C-X-C chemokine ligand 8 (CXCL8) along with its receptor C-X-C chemokine receptor 1 (CXCR1) and chemokine receptor 2 (CXCR2). It plays a significant role in the activation and trafficking of inflammatory mediators, tumor proliferation and interferes in breast cancer development by controlling cell adhesion, proliferation, migration, and metastasis. This axis also plays a significant role in driving different cancers and melanomas, including breast cancer progression, by controlling stem cell masses. Few small-molecule CXCR1/2 inhibitors and CXCL8 releasing inhibitors have been identified in the past two decades that bind these receptors in their inactive forms and blocks their signaling as well as the biological activities associated with inflammation. Inhibitors of certain inflammatory molecules are projected to be more efficient in different inflammatory diseases. Preclinical trials indicate that patients may be benefitted from combined treatment with targeted drugs, chemotherapies, and immunotherapies. Thus, targeting the CXCL8-CXCR1/2 signaling axis in breast cancer could be a promising approach for its therapeutics. This review examines the roles of the CXCL8-CXCR1/2 signaling axis and how it is implicated in the tumor microenvironment in breast cancer. In addition, we also discuss the potential role of the CXCL8-CXCR1/2 axis in targeted therapeutics for breast cancer.

Effect of interleukin-8 receptor B (IL8RB) rs1126579 C>T variation on the risk to cancer

Chemokines are a type of cytokine that participate in the migration of macrophages and monocytes to inflammatory cells. In particular, CXC chemokines are involved in the development of many cancers. Evidence for the association between interleukin-8 receptor B (IL8RB) rs1126579 C > T variation and cancer risk remains contradictory. Here, we utilized a comprehensive analysis containing odds ratios (ORs), regression, and in silico tools to evaluate the effect of IL8RB polymorphism on cancer risk. We further employed Gene set enrichment analysis combined with ELISA to evaluate the IL8RB expression in patients with prostate cancer (PRAD). A total of 5,187 cancer cases and 6,691 controls were included in the present analysis. Individuals with the TT genotype were associated with an increased risk of cancer compared to those with the TC+CC genotype. In a subgroup analysis by type of cancer, individuals with the TT genotype had a 39% increased risk of urinary cancer compared to those with the CC genotype. A subgroup analysis by ethnicity showed that Asians carrying the TC genotype had a 26% lower risk of cancer than those carrying the CC genotype. We found that the expression of IL8RB was down-regulated in PRAD. Compared to that in PRAD subjects carrying the CC genotype, the expression of IL8RB was decreased in patients with the TT+TC genotype. In conclusion, the IL8RB rs1126579 C > T variation may be associated with cancer risk, especially in Asian populations and patients with PRAD.

CCL8 mediates crosstalk between endothelial colony forming cells and triple-negative breast cancer cells through IL-8, aggravating invasion and tumorigenicity

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer with a poor prognosis for which no effective therapeutic measures are currently available. The present study aimed to investigate whether interactions with endothelial colony-forming cells (ECFCs) promote aggressive progression of TNBC cells. Herein, using an indirect co-culture system, we showed that co-culture increased the invasive and migratory phenotypes of both MDA-MB-231 TNBC cells and ECFCs. Through a cytokine antibody array and RT-PCR analysis, we revealed that co-culture markedly induced secretion of the chemokine C-C motif ligand (CCL)8 from ECFCs and that of interleukin (IL)-8 from MDA-MB-231 cells. CCL8 was crucial for ECFC-induced IL-8 secretion and invasion of MDA-MB-231 cells as well as for MDA-MB-231-enhanced MMP-2 secretion and angiogenesis of ECFCs. We suggest c-Jun as a transcription factor for CCL8-induced IL-8 expression in MDA-MB-231 cells. IL-8 was important for co-culture-induced CCL8 and MMP-2 upregulation and invasion of ECFCs. Notably, our findings reveal a positive feedback loop between CCL8 and IL-8, which contributes to the aggressive phenotypes of both ECFC and TNBC cells. Using an MDA-MB-231 cell-based xenograft model, we show that tumor growth and metastasis are increased by co-injected ECFCs in vivo. Increased expression of IL-8 was observed in tissues with bone metastases in mice injected with conditioned media from co-cultured cells. High IL-8 levels are correlated with poor recurrence-free survival in TNBC patients. Together, these results suggest that CCL8 and IL-8 mediate the crosstalk between ECFCs and TNBC, leading to aggravation of tumorigenicity in TNBC.

A Review of Cancer Genetics and Genomics Studies in Africa

Cancer is the second leading cause of death globally and is projected to overtake infectious disease as the leading cause of mortality in Africa within the next two decades. Cancer is a group of genomic diseases that presents with intra- and inter-population unique phenotypes, with Black populations having the burden of morbidity and mortality for most types. At large, the prevention and treatment of cancers have been propelled by the understanding of the genetic make-up of the disease of mostly non-African populations. By the same token, there is a wide knowledge gap in understanding the underlying genetic causes of, and genomic alterations associated with, cancer among black Africans. Accordingly, we performed a review of the literature to survey existing studies on cancer genetics/genomics and curated findings pertaining to publications across multiple cancer types conducted on African populations. We used PubMed MeSH terms to retrieve the relevant publications from 1990 to December 2019. The metadata of these publications were extracted using R text mining packages: RISmed and Pubmed.mineR. The data showed that only 0.329% of cancer publications globally were on Africa, and only 0.016% were on cancer genetics/genomics from Africa. Although the most prevalent cancers in Africa are cancers of the breast, cervix, uterus, and prostate, publications representing breast, colorectal, liver, and blood cancers were the most frequent in our review. The most frequently reported cancer genes were BRCA1, BRCA2, and TP53. Next, the genes reported in the reviewed publications’ abstracts were extracted and annotated into three gene ontology classes. Genes in the cellular component class were mostly associated with cell part and organelle part, while those in biological process and molecular function classes were mainly associated with cell process, biological regulation, and binding, and catalytic activity, respectively. Overall, this review highlights the paucity of research on cancer genomics on African populations, identified gaps, and discussed the need for concerted efforts to encourage more research on cancer genomics in Africa.

Impact of Angiogenesis- and Hypoxia-Associated Polymorphisms on Tumor Recurrence in Patients with Hepatocellular Carcinoma Undergoing Surgical Resection

Simple Summary

Hepatocellular carcinoma remains a leading cause of cancer-related death and the most common primary hepatic malignancy in the Western hemisphere. Previous research found that angiogenesis-related cytokines and elevated levels of interleukin 8 and vascular endothelial growth factor (VEGF) shorten the expected time of survival. Moreover, factors of tumor angiogenesis- and hypoxia-driven signaling pathways are already associated with worse outcome in disease-free survival in several tumor entities. Our study investigates the prognosis of hepatocellular carcinoma patients based on a selection of ten different single-nucleotide polymorphisms from angiogenesis, carcinogenesis, and hypoxia pathways. Our study with 127 patients found supporting evidence that polymorphisms in angiogenesis-associated pathways corelate with disease-free survival and clinical outcome in patients with hepatocellular carcinoma.

Abstract

Tumor angiogenesis plays a pivotal role in hepatocellular carcinoma (HCC) biology. Identifying molecular prognostic markers is critical to further improve treatment selection in these patients. The present study analyzed a subset of 10 germline polymorphisms involved in tumor angiogenesis pathways and their impact on prognosis in HCC patients undergoing partial hepatectomy in a curative intent. Formalin-fixed paraffin-embedded (FFPE) tissues were obtained from 127 HCC patients at a German primary care hospital. Genomic DNA was extracted, and genotyping was carried out using polymerase chain reaction (PCR)–restriction fragment length polymorphism-based protocols. Polymorphisms in interleukin-8 (IL-8) (rs4073; p = 0.047, log-rank test) and vascular endothelial growth factor (VEGF C + 936T) (rs3025039; p = 0.045, log-rank test) were significantly associated with disease-free survival (DFS). After adjusting for covariates in the multivariable model, IL-8 T-251A (rs4073) (adjusted p = 0.010) and a combination of “high-expression” variants of rs4073 and rs3025039 (adjusted p = 0.034) remained significantly associated with DFS. High-expression variants of IL-8 T-251A may serve as an independent molecular marker of prognosis in patients undergoing surgical resection for HCC. Assessment of the patients’ individual genetic risks may help to identify patient subgroups at high risk for recurrence following curative-intent surgery.

An overview of the role of interleukin-8 in colorectal cancer

Colorectal Cancer (CRC), a common malignancy, is developing globally among people. Mutagenic insults activate peripheral nucleated cells to secrete chemokines in order to cause an inflammatory state. Despite the presence of multi-retrieving factors, elevated production of minor cytokines may speed-up the sever stages of the baseline inflammation targeting normal compensatory mechanism. IL-8 is a pro-inflammatory cytokine that is believed to be up-regulated in CRC to proceed primary condition into tumor behavior via induction of proliferation, angiogenesis and metastasis. Here, we assess the role of IL-8 in every step of CRC from signaling pathway and formation to invasion and discuss around new perspective therapy that targets IL-8 to manage CRC worldwide incidence and survival rate, more precisely.

C-X-C motif chemokine receptor type 2 correlates with higher disease stages and predicts worse prognosis, and its downregulation enhances chemotherapy sensitivity in triple-negative breast cancer

BACKGROUND

This study aimed to explore the correlation of C-X-C motif chemokine receptor type 2 (CXCR2) expression with tumor stage and overall survival (OS) in triple-negative breast cancer (TNBC) patients, furthermore, to investigate the influence of CXCR2 downregulation on chemotherapy sensitivity in TNBC cells.

METHODS

One hundred fifty-eight TNBC patients underwent surgical excision were retrospectively reviewed, and CXCR2 expression in tumor tissue was determined by immunohistochemistry (IHC). In vitro, CXCR2 shRNA and control shRNA were transfected into HCC1937 cells respectively. Doxorubicin and docetaxel with different concentrations were used to treat HCC1937 cells respectively, followed by relative cell viability (%) and IC50 measurements.

RESULTS

There were 87 (55.1%) patients presented with CXCR2 high expression, and 71 (44.9%) patients presented with CXCR2 low expression. CXCR2 high expression was positively associated with pathological grade (P=0.007), N stage (P<0.001) and TNM stage (P<0.001), and it predicted unfavorable OS (P<0.001). Further analysis disclosed that CXCR2 high expression independently predicted decreased OS (P=0.028). In vitro, CXCR2 shRNA increased chemosensitivity of HCC1937 cells to doxorubicin and docetaxel, with reduced IC50 concentration of doxorubicin (P<0.05) and docetaxel (P<0.01) compared the control shRNA.

CONCLUSIONS

CXCR2 has the potential to serve as a biomarker for assisting TNBC management and prognosis, and targeting CXCR2 provides a novel strategy to circumvent the chemotherapy resistance.

TGF-β Determines the Pro-migratory Potential of bFGF Signaling in Medulloblastoma

The microenvironment shapes cell behavior and determines metastatic outcomes of tumors. We addressed how microenvironmental cues control tumor cell invasion in pediatric medulloblastoma (MB). We show that bFGF promotes MB tumor cell invasion through FGF receptor (FGFR) in vitro and that blockade of FGFR represses brain tissue infiltration in vivo. TGF-β regulates pro-migratory bFGF function in a context-dependent manner. Under low bFGF, the non-canonical TGF-β pathway causes ROCK activation and cortical translocation of ERK1/2, which antagonizes FGFR signaling by inactivating FGFR substrate 2 (FRS2), and promotes a contractile, non-motile phenotype. Under high bFGF, negative-feedback regulation of FRS2 by bFGF-induced ERK1/2 causes repression of the FGFR pathway. Under these conditions, TGF-β counters inactivation of FRS2 and restores pro-migratory signaling. These findings pinpoint coincidence detection of bFGF and TGF-β signaling by FRS2 as a mechanism that controls tumor cell invasion. Thus, targeting FRS2 represents an emerging strategy to abrogate aberrant FGFR signaling.

Insights on CXC chemokine receptor 2 in breast cancer: An emerging target for oncotherapy

Breast cancer is the most common malignant neoplasm in women worldwide, and the treatment regimens currently available are far from optimal. Targeted therapy, based on molecular typing of breast cancer, is the most precise form of treatment, and CXC chemokine receptor 2 (CXCR2) is one of the molecular markers used in targeted therapies. As a member of the seven transmembrane G-protein-coupled receptor family, CXCR2 and its associated ligands have been increasingly implicated in tumor-associated processes. These processes include proliferation, angiogenesis, invasion, metastasis, chemoresistance, and stemness and phenotypic maintenance of cancer stem cells. Thus, the inhibition of CXCR2 or its downstream signaling pathways could significantly attenuate tumor progression. Therefore, studies on the biological functions of CXCR2 and its association with neoplasia may help improve the prognosis of breast cancer. Furthermore, the targeting of CXCR2 could supplement the present clinical approaches of breast cancer treatment strategies. The present review discusses the structures and mechanisms of CXCR2 and its ligands. Additionally, the contribution of CXCR2 to the development of breast cancer and its potential therapeutic benefits are also discussed.

GOG 8020/210: Risk stratification of lymph node metastasis, disease progression and survival using single nucleotide polymorphisms in endometrial cancer: An NRG oncology/gynecologic oncology group study

OBJECTIVES

The ability to stratify a patient's risk of metastasis and survival permits more refined care. A proof of principle study was undertaken to investigate the relationship between single nucleotide polymorphisms (SNPs) in literature based candidate cancer genes and the risk of nodal metastasis and clinical outcome in endometrioid endometrial cancer (EEC) patients.

METHODS

Surgically-staged EEC patients from the Gynecologic Oncology Group or Washington University School of Medicine with germline DNA available were eligible. Fifty-four genes represented by 384 SNPs, were evaluated by Illumina Custom GoldenGate array. Association with lymph node metastases was the primary outcome. Progression-free survival (PFS) and overall survival (OS) was also evaluated.

RESULTS

361 SNPs with high quality genotype data were evaluated in 337 patients with outcome data. Five SNPs in CXCR2 had an odds ratio (OR) between 0.68 and 0.70 (p-value ≤ 0.025). The A allele rs946486 in ABL had an OR of 1.5 (p-value = 0.01) for metastasis. The G allele in rs7795743 in EGFR had an OR for metastasis of 0.68 (p-value = 0.02) and hazard ratio (HR) for progression of 0.66 (p-value = 0.004). Importantly, no SNP met genome wide significance after adjusting for multiple test correcting and clinical covariates. The A allele in rs2159359 SNP in NME1 and the G allele in rs13222385 in EGFR were associated with worse OS. Both exhibited genome wide significance; rs13222385 remained significant after adjusting for prognostic clinical variables.

CONCLUSION

SNPs in cancer genes including rs2159359 SNP in NME1 and rs13222385 in EGFR may stratify risk in EEC and are prioritized for further investigation.

The effect of human placental chorionic villi derived mesenchymal stem cell on triple-negative breast cancer hallmarks

Mesenchymal stem cells (MSCs) can influence the tumour microenvironment (TEM) and play a major role in tumourigenesis. Triple-negative [Ostrogen receptor (ER-), Progesterone receptor (PgR-), and HER2/neu receptor (HER2-)] breast cancer (TNBC) is an aggressive class of BC characterized by poor prognosis and lacks the benefit of routinely available targeted therapies. This study aims to investigate the effect of human placental chorionic villi derived MSCs (CVMSCs) on the behavior of TNBC in vitro. This was done by assaying different cancer hallmarks including proliferation, migration and angiogenesis. Cell proliferation rate of TNBC cell line (MDA-MB231) was monitored in real time using the xCELLigence system. Whereas, Boyden chamber migration assay was used to measure MDA-MB231 motility and invasiveness toward CVMSCs. Finally, a three-dimensional (3D) model using a co-culture system of CVMSCs with MDA-MB231 with or without the addition of human umbilical vein endothelial cells (HUVECs) was created to assess tumour angiogenesis in vitro. CVMSCs were able to significantly reduce the proliferative and migratory capacity of MDA-MB231 cells. Co-culturing of MDA-MB231 with CVMSCs, not only inhibited the tube formation ability of HUVECs but also reduced the expression of the BC characteristic cytokines; IL-10, IL-12, CXCL9 and CXCL10 of CVMSCs. These results support the hypothesis that CVMSCs can influence the behavior of TNBC cells and provides a basic for a potential therapeutic approach in a pre-clinical settings. The data from this study also highlight the complexity of the in vitro cancer angiogenesis model settings and regulations.

Orientin inhibits invasion by suppressing MMP-9 and IL-8 expression via the PKCα/ ERK/AP-1/STAT3-mediated signaling pathways in TPA-treated MCF-7 breast cancer cells

BACKGROUND

Orientin (luteolin 8-C-β-D-glucopyranoside), a glycosyl dietary flavonoid, has therapeutic effects such as anti-inflammation and antiadipogenesis. However, there is little known about the antimigratory and anti-invasive effects of orientin. Thus, we demonstrate the anti-invasive effects of orientin compared with well-known anticancer flavonoid, luteolin and luteolin 8-C-β-fucopyranoside (LU8C-FP).

PURPOSE

We investigated whether orientin would inhibit the migration and invasion of 12-O-tetradecanoyl phorbol-13-acetate (TPA) induced MCF-7 breast cancer cells.

METHODS

We investigated the anti-invasive mechanism of orientin by using wound-healing assay, Matrigel invasion assay, gelatin zymography, qRT-PCR, ELISA, western blotting, nuclear, membrane and cytosolic fractionations, and immunofluorescence staining in MCF-7 cell line.

RESULTS

We demonstrated the antimigratory and anti-invasive effects of orientin in TPA-treated MCF-7 cells. TPA-induced membrane translocation of protein kinase C alpha (PKCα), phosphorylation of extracellular signal regulated kinase (ERK), and nuclear translocations of activator protein-1 (AP-1) and signal transducer and activator of transcription 3 (STAT3) were downregulated by orientin. In addition, orientin also inhibited matrix metalloproteinase-9 (MMP-9) and interleukin-8 (IL-8) expression.

CONCLUSION

Orientin inhibits migratory and invasive responses by suppressing MMP-9 and IL-8 expression through mitigation of TPA-induced PKCα and ERK activation, as well as the nuclear translocation of AP-1 and STAT3. Therefore, orientin prevents tumor invasion and could be applied as a possible therapeutic agent for the treatment of cancer metastasis.

Genetic Modifiers of the Breast Tumor Microenvironment

Multiple nonmalignant cell types in the tumor microenvironment (TME) impact breast cancer risk, metastasis, and response to therapy, yet most heritable mechanisms that influence TME cell function and breast cancer outcomes are largely unknown. Breast cancer risk is ∼30% heritable and >170 genetic loci have been associated with breast cancer traits. However, the majority of candidate genes have poorly defined mechanistic roles in breast cancer biology. Research indicates that breast cancer risk modifiers directly impact cancer cells, yet it is equally plausible that some modifier alleles impact the nonmalignant TME. The objective of this review is to examine the list of current breast cancer candidate genes that may modify breast cancer risk and outcome through the TME.

Role of Intracystic Cytokines and Nitric Oxide in Ovarian Neoplasms

The development of new biomarkers for the diagnosis and prognosis of ovarian cancer may provide an opportunity for new therapies. In this study, we aimed to compare cytokines (interleukin [IL]-2, IL-5, IL-6, IL-8, IL-10 and tumour necrosis factor [TNF]-α) and nitric oxide (NO) metabolite levels in non-neoplastic tumours, benign primary ovarian tumours and malignant primary ovarian neoplasms. The secondary aim was to relate cytokine and intracystic NO metabolite levels to clinical, laboratory and pathologic characteristics for patients with primary ovarian malignancies. We evaluated 110 patients with adnexal masses. Cytokine concentrations were quantified by enzyme-linked immunosorbent assay and nitrate concentrations by enzymatic reduction of nitrite by nitrate reductase. Patients with malignant neoplasms had higher IL-6, IL-8 and NO levels compared to patients with benign neoplasms. Histologic grade 1 tumours were associated with elevated IL-2 levels, whereas anaemia was associated with elevated IL-6 levels. On average, those patients with elevated IL-8 levels also had a neutrophil/lymphocyte ratio (NLR) greater than 2.6 and less than 36 months of disease-free survival (DFS). Patients with normal CA 19-9 levels had elevated IL-10 levels. TNF-α was elevated in patients with two carcinogenesis and those with a platelet/lymphocyte ratio (PLR) less than 300. NO levels were higher in patients with an NLR less than 2.6 and CA 19-9 greater than 35 U/ml. Elevated intracystic cytokine levels, especially IL-6 and IL-8, are associated with worse prognosis in ovarian cancer.

Analysis of aqueous humor concentrations of cytokines in retinoblastoma

To investigate the components of the aqueous humor (AH) in patients with retinoblastoma (RB). We collected 0.1 ml AH of 35 children with RB and 20 patients with congenital cataracts as controls. Multiplex enzyme-linked immunosorbent assays (ELISAs) and Luminex xMAP technology were used to assess 45 cytokines/chemokines, matrix metalloproteinases (MMPs), and acute-phase proteins in the identification cohort. The concentrations of IL-6, IL-7, IL-8, IFN-γ, PIGF-1, VEGF-A, β-NGF, HGF, EGF and FGF-2 were significantly higher in the AH of patients with RB than those in the control group (P<0.05). The study showed that the higher levels of IP-10, IL-6, IL-7, IL-8, IFN-γ, PIGF-1, VEGF-A, β-NGF, HGF, EGF and FGF-2 in AH may be associated with RB. Our findings may facilitate a better understanding of the molecular pathways of tumors and solid molecular targets for new strategies for therapy and the earlier diagnosis of RB.

Hyaluronic Acid Nanohydrogel Loaded With Quercetin Alone or in Combination to a Macrolide Derivative of Rapamycin RAD001 (Everolimus) as a New Treatment for Hormone-Responsive Human Breast Cancer

The aim of this study is based on the evaluation of anticancer, anti-inflammatory activities, and cellular uptake of hyaluronic acid nanohydrogel of quercetin tested alone and in combination to a macrolide derivative of rapamycin RAD001 (everolimus) on hormone-responsive breast cancer cell line MCF-7. Biological investigations were focused on the receptor mediated cellular internalization of the nanohydrogel and its abilities to reduce secretion of several cytokines (IL-8, IL-6, IL-19), VEGF, and metalloproteases (MMP-2, MMP-9) under pro-inflammatory conditions. Nanohydrogel show a CD44 dependent endocytosis with evident time dependent cytoplasmatic accumulation with abilities to reduce secretion of all cytokines of ∼60% compared to untreated cells. Combination of formulated quercetin and everolimus leads to a synergistic cytotoxic effects with a Combination Index of 0.38. These results highlights the importance of synergistic effect of the hyaluronic acid nanohydrogel of quercetin with everolimus in the regulation of human breast cancer cell proliferation and emphasize the antitumor and anti-inflammatory properties of the nanocarrier. J. Cell. Physiol. 232: 2063-2074, 2017. © 2016 Wiley Periodicals, Inc.

Taxotere-induced elevated expression of IL8 in carcinoma-associated fibroblasts of breast invasive ductal cancer

Breast cancer is the most common malignant tumor in women worldwide, and accounts for an estimated 29% of new cases and 15% of cancer-associated mortalities each year. Invasive ductal carcinoma represents 70-80% of all breast cancer cases, which are responsible for the majority of breast cancer fatalities. Though great progress has been made in understanding the tumorigenesis and development of breast cancer, problems surrounding treatment persist. It was previously reported that carcinoma-associated fibroblasts (CAFs) may be closely associated with chemotherapy resistance. In the present study, primary-cultured CAFs from surgically resected breast invasive ductal cancer tissues were prepared and tested to clarify the change of gene expression profile following treatment with 20 ng/ml Taxotere^® for 24 h through microarray analysis. In addition, quantitative polymerase chain reaction and western blotting were performed to compare the gene and protein expression of the candidate gene in CAFs prior to and following Taxotere treatment. Based on the obtained data, 35 differentially expressed genes were identified, including ACTA2, ACTC1, ACTG, ALDH1B1, AMY1A, C5orf13, CNN1, CXCR7, DDAH1, FGF1, PDLIM3, MAMLD1, MYH11, OXTR, PDLIM5, RARRES1, SERPINA3, TRIL, C14orf43, C1orf51, CXCL12, CXCL2, EGR2, EGR3, IER3, interleukin (IL)8, IRF1, JUNB, MMP1, NAV2, NFKBIA, NFKBIZ, TRIB1, WNT16 and ZC3H12A. It was observed that the expression of the candidate gene IL8 in the CAFs of breast invasive cancer following treatment with Taxotere was increased (P<0.05). Overall, elevated expression of IL8 induced by Taxotere in CAFs potentially supports the association between IL8 and chemotherapy response.

Novel augmentation by bufalin of protein kinase C-induced cyclooxygenase-2 and IL-8 production in human breast cancer cells

Cyclooxygenase-2 (COX-2) and IL-8 are two inflammatory mediators induced by protein kinase C (PKC) via various stimuli. Both contribute significantly to cancer progression. Bufalin, a major active component of the traditional Chinese medicine Chan Su, is known to induce apoptosis in various cancer cells. This study clarifies the role and mechanism of bufalin action during PKC regulation of COX-2/IL-8 expression and investigates the associated impact on breast cancer. Using MB-231 breast cancer cells, bufalin augments PKC induction of COX-2/IL-8 at both the protein and mRNA levels, and the production of prostaglandin E2 (PGE2) and IL-8. The MAPK and NF-κB pathways are involved in both the PKC-mediated and bufalin-promoted PKC regulation of COX-2/IL-8 production. Bufalin increases PKC-induced MAPKs phosphorylation and NF-κB nuclear translocation. PGE2 stimulates the proliferation/migration of breast cancer cells. Furthermore, PKC-induced matrix metalloproteinase 3 expression is enhanced by bufalin. Bufalin significantly enhances breast cancer xenograft growth, which is accompanied by an elevation in COX-2/IL-8 expression. In conclusion, bufalin seems to promote the inflammatory response in vitro and in vivo, and this occurs, at least in part, by targeting the MAPK and NF-κB pathways, which then enhances the growth of breast cancer cells.

E-cadherin genetic variants predict survival outcome in breast cancer patients

BACKGROUND

E-cadherin is a major component of adherens junctions that regulates cell shape and maintains tissue integrity. A complete loss or any decrease in cell surface expression of E-cadherin will interfere with the cell-to-cell junctions' strength and leads to cell detachment and escape from the primary tumor site. In this prospective study, three functional single nucleotide polymorphisms (-347G/GA, rs5030625; -160C/A, rs16260; +54C/T, rs1801026), were found to modulate E-cadherin expression.

METHODS

577 DNA samples from breast cancer (BC) cases were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

We detected no significant correlations between each polymorphism and the clinical parameters of the patients whereas the GACC haplotype was significantly associated with low SBR grading. Overall survival analysis showed that both -347G/G and +54C/C wild (wt) genotypes had a significantly worse effect compared to the other genotypes (non-wt). Moreover, carrying simultaneously both the -347 and +54 wt genotypes confers a significantly higher risk of death. However, with metastatic recurrence, the death-rate was null in patients carrying the non-wt genotypes, and attained 37% in those carrying the wt genotype. A multivariate analysis showed that these two polymorphisms are independent prognostic factors for overall survival in BC patients.

CONCLUSIONS

Our results support the fact that E-cadherin genetic variants control disease severity and progression and could be a marker of disease outcome. These findings could be useful in selecting patients that should be monitored differently.

The CXCL8-CXCR1/2 pathways in cancer

Persistent infection or chronic inflammation contributes significantly to tumourigenesis and tumour progression. C-X-C motif ligand 8 (CXCL8) is a chemokine that acts as an important multifunctional cytokine to modulate tumour proliferation, invasion and migration in an autocrine or paracrine manner. Studies have suggested that CXCL8 and its cognate receptors, C-X-C chemokine receptor 1 (CXCR1) and CX-C chemokine receptor 2 (CXCR2), mediate the initiation and development of various cancers including breast cancer, prostate cancer, lung cancer, colorectal carcinoma and melanoma. CXCL8 also integrates with multiple intracellular signalling pathways to produce coordinated effects. Neovascularisation, which provides a basis for fostering tumour growth and metastasis, is now recognised as a critical function of CXCL8 in the tumour microenvironment. In this review, we summarize the biological functions and ficlinical significance of the CXCL8 signalling axis in cancer. We also propose that CXCL8 may be a potential therapeutic target for cancer treatment

Cytokine Regulation of Metastasis and Tumorigenicity

The human body combats infection and promotes wound healing through the remarkable process of inflammation. Inflammation is characterized by the recruitment of stromal cell activity including recruitment of immune cells and induction of angiogenesis. These cellular processes are regulated by a class of soluble molecules called cytokines. Based on function, cell target, and structure, cytokines are subdivided into several classes including: interleukins, chemokines, and lymphokines. While cytokines regulate normal physiological processes, chronic deregulation of cytokine expression and activity contributes to cancer in many ways. Gene polymorphisms of all types of cytokines are associated with risk of disease development. Deregulation RNA and protein expression of interleukins, chemokines, and lymphokines have been detected in many solid tumors and hematopoetic malignancies, correlating with poor patient prognosis. The current body of literature suggests that in some tumor types, interleukins and chemokines work against the human body by signaling to cancer cells and remodeling the local microenvironment to support the growth, survival, and invasion of primary tumors and enhance metastatic colonization. Some lymphokines are downregulated to suppress tumor progression by enhancing cytotoxic T cell activity and inhibiting tumor cell survival. In this review, we will describe the structure/function of several cytokine families and review our current understanding on the roles and mechanisms of cytokines in tumor progression. In addition, we will also discuss strategies for exploiting the expression and activity of cytokines in therapeutic intervention.

Association of –607 C/A Polymorphism of IL-18 Gene (rs1946518) with Breast Cancer Risk in Zahedan, Southeast Iran

It is known that interleukin-18 (IL-18) is a proinflammatory cytokine with dual effects on tumor development and progression. It can increase the immune defense against tumor cells. Polymorphisms in the IL-18 genes are known to influence both expression levels and may be associated with outcome of cancers. This study was aimed to find out the possible association of IL-18 polymorphism at position –607 C/A (rs1946518) with breast cancer in a sample of Iranian population. We investigated IL-18 rs1946518 polymorphism on 72 breast cancer patients and 93 cancer free women. Genotyping was done using amplification refractory mutation system-PCR (ARMS-PCR). We found no significant differences between breast cancer patients and control subjects regarding IL-18 rs1946518 polymorphism (χ2=1.78, p=0.411). In conclusion, our finding showed that IL-18 rs1946518 polymorphism was not associated with breast cancer in a sample of Iranian population.

Association between IL-8 -251A/T and IL-10 -1082A/G genetic polymorphisms and susceptibility to colorectal cancer: A case-control study in a population in Shaanxi

AIM: To explore the association between IL-8 -251A/T and IL-10 -1082A/G polymorphisms and susceptibility to colorectal cancer (CRC) in the population in Shaanxi, China.

METHODS: A case-control study was performed to compare the distribution of genetic frequencies and genotype of IL-8 -251A/T and IL-10 -1082A/G among colorectal cancer patients (n = 102) and control healthy individuals (n = 105) using allele specific PCR (AS-PCR). The relationship between IL-8 -251A/T and IL-10 -1082A/G polymorphisms and susceptibility to colorectal cancer was explored.

RESULTS: There was a significant difference in the distribution of genotype of IL-8 -251A/T between the healthy control group and CRC group (χ² = 8.278, P = 0.016). The genetic frequency of IL-8 -251A allele in CRC was 0.54 (111/204), which was significantly higher than that of the controls (0.43, 91/210) (χ² = 5.083; P = 0.024). The subjects carrying AA genotype were more likely to suffer from CRC (OR = 3.84, 95%CI: 1.44-10.23). Stratified analysis suggested that the association between the AA genotype of IL-8 -251A/T and the risk of CRC was more profound in subjects less than 55 years old and smokers. However, no difference was discovered in the distribution of genotype of IL-10 -1082A/G between the CRC group and healthy control group (χ² = 1.808, P = 0.405).

CONCLUSION: The IL-8 -251AA genotype may be a risk factor of CRC in the population in Shaanxi, and people with A allele may be more likely to suffer from CRC, especially in those less than 55 years old and smokers. No correlation is found between IL-10 -1082A/G polymorphism and the risk of CRC.

Potential impact of human papilloma virus on survival of basaloid squamous carcinoma of the head and neck

OBJECTIVES

Basaloid-squamous-carcinomas (BSCC) have been considered as aggressive variants of common squamous-cell-carcinomas (HNSCC). Recent studies demonstrated a different clinical course depending on the tumour site. The aim of the study is to analyze the histopathologic/clinical features of BSCC/HNSCC resolved by the HPV-status.

METHODS

We analysed the histopathologic/clinical features of BSCC (n=59) and HNSCC (n=981), subdivided due to the HPV status. Differences were analysed using Chi square, Fisher exact, and student's t-test. Survival rates were calculated by Kaplan-Meier and log-rank test. Prognostic variables were subsequently evaluated by Cox regression.

RESULTS

Our cohort was congruent with the literature regarding sex, age, metastases, and a predilection in the oropharynx. HNSCC/BSCC did not show a different disease-specific-survival. After UICC matching, univariate analysis revealed a better survival of UICC stage IVa BSCC compared to HNSCC (69% vs. 42%, p=0.022) that was associated with a better response to radio-chemotherapy (p = 0.009). These results referred to the high prevalence of HPV+ (86%) oropharyngeal BSCC. Subgroup analysis demonstrated a better survival of HPV+ oropharyngeal BSCC than HPV- BSCC (p=0.017).

CONCLUSION

The clinical outcome in BSCC depends on the tumour site and HPV-status. Prospective studies have to evaluate the beneficial application of postoperative radio-chemotherapy in HPV+ BSCC.

Association analysis of ERCC5 gene polymorphisms with risk of breast cancer in Han women of northwest China

BACKGROUND

ERCC5 plays an important role in DNA damage repair. Mutations in it will lead to DNA repair defects and genomic instability. Its functional single nucleotide polymorphisms (SNPs) may alter DNA repair capacity and affect cancer susceptibility.

METHODS

This study aims to evaluate the association between SNPs in ERCC5 and breast cancer susceptibility in Han women subjects genetically from northwest China. A total of 101 breast cancer patients and 101 healthy controls provided blood samples for analysis of ERCC5 rs17655 and rs751402 genotypes.

RESULTS

After adjusting covariates, rs751402 homozygote AA and heterozygote AG were found to confer statistically significant protections (OR 0.052, 95% CI 0.006-0.411, P = 0.005; OR 0.145, 95% CI 0.067-0.315, P < 0.001, respectively) against breast cancer. Moreover, both of the dominant and recessive models of rs751402 also conferred a decreased risk of breast cancer (AA + AG vs. GG, OR 0.125, 95% CI 0.060-0.261, P < 0.001; AA vs. GG + AG, OR 0.082, 95% CI 0.010-0.648, P = 0.018, respectively).

CONCLUSIONS

The results indicate that the rs751402 in ERCC5 may affect the risk of breast cancer and show that it is associated with breast cancer characteristics in the Han population of northwest China. However, we found no significant differences between breast cancer patients and control subjects regarding ERCC5 rs17655 polymorphism in the studied population.

Relationships between Family Levels of Socioeconomic Status and Distribution of Breast Cancer Risk Factors

BACKGROUND

Not only the expand development of knowledge for reducing risk factors, but also the improvement in early diagnosis and treatment of cancer, and socioeconomic inequalities could affect cancer incidence, diagnosis stage, and mortality. The aim of this study was investigation the relationships between family levels of socioeconomic status and distribution of breast cancer risk factors.

METHODS

This descriptive cross-sectional study has conducted on 526 patients who were suffering from breast cancer, and have registered in Cancer Research Center of Shahid Beheshti University of Medical Sciences from March 2008 to December 2013. A reliable and valid questionnaire about family levels of socioeconomic status has filled by interviewing the patients via phone. For analyzing the data, Multinomial logistic regression, Kendal tau-b correlation coefficient and Contingency Coefficient tests have executed by SPSS19.

RESULTS

The mean age of the patients was 48.30 (SD=11.41). According to the results of this study, there was a significant relationship between family socioeconomic status and patient's age at diagnosis of breast cancer (p value<0.001). Also, the relationships between socioeconomic status and number of pregnancies, and duration of breast feeding were significant (p value> 0.001). In the multiple logistic regressions, the relationship between excellent socioeconomic status and number of abortions was significant (p value> 0.007). Furthermore, the relationships between moderate and good socioeconomic statuses and smoking were significant (p value=0.05 and p value=0.02, respectively).

CONCLUSION

The results have indicated that among those patients having better socioeconomic status, age at cancer diagnosis, number of pregnancies and duration of breast feeding was lower, and then number of abortions was more than the others. According to the results of this study, it was really important to focus on family socioeconomic status as a critical and effective variable on breast cancer risk factors among the Iranian women.

Recent advances reveal IL-8 signaling as a potential key to targeting breast cancer stem cells

Breast cancer stem-like cells (CSCs) are an important therapeutic target as they are purported to be responsible for tumor initiation, maintenance, metastases, and disease recurrence. Interleukin-8 (IL-8) is upregulated in breast cancer compared with normal breast tissue and is associated with poor prognosis. IL-8 is reported to promote breast cancer progression by increasing cell invasion, angiogenesis, and metastases and is upregulated in HER2-positive cancers. Recently, we and others have established that IL-8 via its cognate receptors, CXCR1 and CXCR2, is also involved in regulating breast CSC activity. Our work demonstrates that in metastatic breast CSCs, CXCR1/2 signals via transactivation of HER2. Given the importance of HER2 in breast cancer and in regulating CSC activity, a pathway driving the activation of these receptors would have important biological and clinical consequences, especially in tumors that express high levels of IL-8 and other CXCR1/2-activating ligands. Here, we review the IL-8 signaling pathway and the role of HER2 in maintaining an IL-8 inflammatory loop and discuss the potential of combining CXCR1/2 inhibitors with other treatments such as HER2-targeted therapy as a novel approach to eliminate CSCs and improve patient survival.

Receptor-defined subtypes of breast cancer in indigenous populations in Africa: a systematic review and meta-analysis

BACKGROUND

Breast cancer is the most common female cancer in Africa. Receptor-defined subtypes are a major determinant of treatment options and disease outcomes but there is considerable uncertainty regarding the frequency of poor prognosis estrogen receptor (ER) negative subtypes in Africa. We systematically reviewed publications reporting on the frequency of breast cancer receptor-defined subtypes in indigenous populations in Africa.

METHODS AND FINDINGS

Medline, Embase, and Global Health were searched for studies published between 1st January 1980 and 15th April 2014. Reported proportions of ER positive (ER+), progesterone receptor positive (PR+), and human epidermal growth factor receptor-2 positive (HER2+) disease were extracted and 95% CI calculated. Random effects meta-analyses were used to pool estimates. Fifty-four studies from North Africa (n=12,284 women with breast cancer) and 26 from sub-Saharan Africa (n=4,737) were eligible. There was marked between-study heterogeneity in the ER+ estimates in both regions (I2>90%), with the majority reporting proportions between 0.40 and 0.80 in North Africa and between 0.20 and 0.70 in sub-Saharan Africa. Similarly, large between-study heterogeneity was observed for PR+ and HER2+ estimates (I2>80%, in all instances). Meta-regression analyses showed that the proportion of ER+ disease was 10% (4%-17%) lower for studies based on archived tumor blocks rather than prospectively collected specimens, and 9% (2%-17%) lower for those with ≥ 40% versus those with <40% grade 3 tumors. For prospectively collected samples, the pooled proportions for ER+ and triple negative tumors were 0.59 (0.56-0.62) and 0.21 (0.17-0.25), respectively, regardless of region. Limitations of the study include the lack of standardized procedures across the various studies; the low methodological quality of many studies in terms of the representativeness of their case series and the quality of the procedures for collection, fixation, and receptor testing; and the possibility that women with breast cancer may have contributed to more than one study.

CONCLUSIONS

The published data from the more appropriate prospectively measured specimens are consistent with the majority of breast cancers in Africa being ER+. As no single subtype dominates in the continent availability of receptor testing should be a priority, especially for young women with early stage disease where appropriate receptor-specific treatment modalities offer the greatest potential for reducing years of life lost. Please see later in the article for the Editors' Summary.

Roles of CXCL5 on migration and invasion of liver cancer cells

Inflammatory factors play a vital role in the progression of liver cancer, although exact factors and related mechanisms still remain unclear. The present study aimed at screening inflammatory factors related to liver cancer metastasis and investigating the potential mechanism by which cancer cells are recruited. We screened and validated inflammatory factors by microarray and RT-PCR. Small interfering RNA (siRNA) and recombinant protein were used to assess CXCL5 effects on the movement of liver cancer cells (LCCs). Our screening microarray demonstrated over-expression of CXCL5 in LCCs with high metastatic potentials. CXCL5 increased LCCs migration and invasion, probably through autocrine and paracrine mechanisms. CXCL5-CXCR2 and ERK1/2 pathways could play critical roles in the regulation of LCCs migration. Our data indicates that LCCs per se may act as the producer and receptor of CXCL5 responsible for liver cancer migration and invasion.

The chemokine receptors CXCR1 and CXCR2 regulate oral cancer cell behaviour

BACKGROUND

Chemokines regulate physiological and pathological leucocyte trafficking, and chemokine receptors play a role in tumorigenesis. Expression of interleukin-8 (IL-8) receptors CXCR1 and CXCR2 has been shown in oral squamous cell carcinoma (OSCC) but remains poorly characterised. This aim of this study was to investigate CXCR1 and CXCR2 expression on normal oral keratinocytes (NOKs) and oral cancer cell lines (OCCL) and their relative response when exposed to IL-8 and growth-related oncogene-α (which selectively binds CXCR2).

METHODS

mRNA and protein expression was studied using RT-PCR, immunocytochemistry and flow cytometry. ELISAs were used to investigate ERK1/2 phosphorylation and MMP production, whereas a MTS-based assay was employed to study proliferation. Migration assays were carried out using modified Boyden chambers with a matrigel coating used for invasion assays.

RESULTS

mRNA expression of CXCR1 and CXCR2 was seen in both NOKs and OCCL with significantly higher protein expression in OCCL. Exposure to IL-8 and GROα increased intracellular ERK phosphorylation, proliferation, migration and invasion with OCCL showing a greater response than NOKs. These effects were mediated through CXCR1 and CXCR2 (for IL-8) and CXCR2 (for GROα) as receptor-blocking antibodies significantly inhibited the responses. IL-8 and GROα also increased MMP-9 release from NOKs and OCCL with significantly higher amounts released by OCCL. However, an increase in MMP-7 production was only seen in OCCL.

CONCLUSIONS

Functional CXCR1 and CXCR2 exist on normal and cancerous oral epithelial cells, and our data suggests a role for these receptors in oral cancer biology.

The polymorphism interleukin-8 -251A/T is associated with a significantly increased risk of cancers from a meta-analysis

Emerging evidences show that interleukin-8 (IL-8) has important regulatory functions in tumorigenesis. IL-8 -251A/T is a single nucleotide polymorphism in the promoter region of the IL-8 gene and affects IL-8 production. Analysis of previous studies on the association of -251A/T polymorphism with different cancer types remained to be illustrated. To further assess the effect of -251A/T polymorphism on cancer risks, we performed this meta-analysis, up to November 2013, of 12,917 cases with different cancer types and 17,689 controls from 47 published case-control designed studies. Statistical analyses were performed using STATA 11.0 software. Crude odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the strength of associations. ORs with 95 % CIs for IL-8 -251A/T polymorphism and cancer were estimated using fixed- and random-effects models when appropriate. Significantly increased risks were found in overall under the models of A allele vs. T allele, AA vs. TT, and AA vs. AT/TT. Significantly elevated risks were observed in breast cancer under the models of A allele vs. T allele, AT vs. TT, AA/AT vs. TT, and AA vs. AT/TT, and in nasopharyngeal carcinoma under the models of AT vs. TT, AA/AT vs. TT, and AA vs. AT/TT. We found that significantly elevated risks were observed in the Asian population and hospital-based studies in all comparison models. Thus, this meta-analysis indicates that IL-8 -251A/T polymorphism is associated with a significantly increased risk of cancers and may provide evidence-based medical certificate to study the cancer susceptibility.

Genetic variants in interleukin genes are associated with breast cancer risk and survival in a genetically admixed population: the Breast Cancer Health Disparities Study

Interleukins (ILs) are key regulators of immune response. Genetic variation in IL genes may influence breast cancer risk and mortality given their role in cell growth, angiogenesis and regulation of inflammatory process. We examined 16 IL genes with breast cancer risk and mortality in an admixed population of Hispanic/Native American (NA) (2111 cases and 2597 controls) and non-Hispanic white (NHW) (1481 cases and 1585 controls) women. Adaptive Rank Truncated Product (ARTP) analysis was conducted to determine gene significance and lasso (least absolute shrinkage and selection operator) was used to identify potential gene by gene and gene by lifestyle interactions. The pathway was statistically significant for breast cancer risk overall (P ARTP = 0.0006), for women with low NA ancestry (P(ARTP) = 0.01), for premenopausal women (P(ARTP) = 0.02), for estrogen receptor (ER)+/progesterone receptor (PR)+ tumors (P(ARTP) = 0.03) and ER-/PR- tumors (P(ARTP) = 0.02). Eight of the 16 genes evaluated were associated with breast cancer risk (IL1A, IL1B, IL1RN, IL2, IL2RA, IL4, IL6 and IL10); four genes were associated with breast cancer risk among women with low NA ancestry (IL1B, IL6, IL6R and IL10), two were associated with breast cancer risk among women with high NA ancestry (IL2 and IL2RA) and four genes were associated with premenopausal breast cancer risk (IL1A, IL1B, IL2 and IL3). IL4, IL6R, IL8 and IL17A were associated with breast cancer-specific mortality. We confirmed associations with several functional polymorphisms previously associated with breast cancer risk and provide support that their combined effect influences the carcinogenic process.

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.

Effect of genetic variants in two chemokine decoy receptor genes, DARC and CCBP2, on metastatic potential of breast cancer

The inhibitory effect of two chemokine decoy receptors (CDRs), DARC and D6, on breast cancer metastasis is mainly due to their ability to sequester pro-malignant chemokines. We hypothesized that genetic variants in the DARC and CCBP2 (encoding D6) genes may be associated with breast cancer progression. In the present study, we evaluated the genetic contributions of DARC and CCBP2 to metastatic potential, indicated by lymph node metastasis (LNM). Ten single-nucleotide polymorphisms (SNPs) (potentially functional SNPs and block-based tagging SNPs) in DARC and CCBP2 were genotyped in 785 breast cancer patients who had negative lymph nodes and 678 patients with positive lymph nodes. Two non-synonymous SNPs, rs12075 (G42D) in DARC and rs2228468 (S373Y) in CCBP2, were observed to be associated with LNM in univariate analysis and remained significant after adjustment for conventional clinical risk factors, with odds ratios (ORs) of 0.54 (95% confidence interval [CI], 0.37 to 0.79) and 0.78 (95% CI, 0.62 to 0.98), respectively. Additional functional experiments revealed that both of these significant SNPs could affect metastasis of breast cancer in xenograft models by differentially altering the chemokine sequestration ability of their corresponding proteins. Furthermore, heterozygous GD genotype of G42D on human erythrocytes had a significantly stronger chemokine sequestration ability than homozygous GG of G42D ex vivo. Our data suggest that the genetic variants in the CDR genes are probably associated with the varied metastatic potential of breast cancer. The underlying mechanism, though it needs to be further investigated, may be that CDR variants could affect the chemokine sequestration ability of CDR proteins.