Plasma YKL-40: a potential new cancer biomarker?

Overexpression of CHI3L1 is associated with chemoresistance and poor outcome of epithelial ovarian carcinoma

We propose CHI3L1 as a prognostic biomarker for patients with epithelial ovarian carcinoma (EOC) and also suggest possible biological functions of CHI3L1. We measured CHI3L1 expression with quantitative real time-polymerase chain reaction (qRT-PCR) in 180 women with EOC and evaluated correlations between CHI3L1 expression, clinicopathological characteristics, and the outcomes of the patients. The expression of CHI3L1 was higher in cancerous tissues than in normal tissues. The expression of CHI3L1 was also higher in patients with a serous histological type, advanced stage, and chemoresistance. Patients with high CHI3L1 expression had a shorter progression-free survival (p < 0.001)and overall survival (p < 0.001). Patients with high CHI3L1 expression also had a high risk of recurrence (p < 0.001)and death (p < 0.001). In vitro studies showed that CHI3L1 up-regulated the expression of anti-apoptotic Mcl-1 protein and hampered paclitaxel-induced apoptosis of ovarian cancer cells. These results suggest that CHI3L1 shows potential as a prognostic biomarker for EOC. CHI3L1 may promote chemoresistance via inhibition of drug-induced apoptosis by up-regulating Mcl-1.

Increased Obesity-Associated Circulating Levels of the Extracellular Matrix Proteins Osteopontin, Chitinase-3 Like-1 and Tenascin C Are Associated with Colon Cancer

BACKGROUND

Excess adipose tissue represents a major risk factor for the development of colon cancer with inflammation and extracellular matrix (ECM) remodeling being proposed as plausible mechanisms. The aim of this study was to investigate whether obesity can influence circulating levels of inflammation-related extracellular matrix proteins in patients with colon cancer (CC), promoting a microenvironment favorable for tumor growth.

METHODS

Serum samples obtained from 79 subjects [26 lean (LN) and 53 obese (OB)] were used in the study. Enrolled subjects were further subclassified according to the established diagnostic protocol for CC (44 without CC and 35 with CC). Anthropometric measurements as well as circulating metabolites and hormones were determined. Circulating concentrations of the ECM proteins osteopontin (OPN), chitinase-3-like protein 1 (YKL-40), tenascin C (TNC) and lipocalin-2 (LCN-2) were determined by ELISA.

RESULTS

Significant differences in circulating OPN, YKL-40 and TNC concentrations between the experimental groups were observed, being significantly increased due to obesity (P<0.01) and colon cancer (P<0.05). LCN-2 levels were affected by obesity (P<0.05), but no differences were detected regarding the presence or not of CC. A positive association (P<0.05) with different inflammatory markers was also detected.

CONCLUSIONS

To our knowledge, we herein show for the first time that obese patients with CC exhibit increased circulating levels of OPN, YKL-40 and TNC providing further evidence for the influence of obesity on CC development via ECM proteins, representing promising diagnostic biomarkers or target molecules for therapeutics.

Serum YKL-40 and gestational diabetes - an observational cohort study

To examine serum YKL-40 in women developing gestational diabetes mellitus (GDM). In the present large observational cohort study of 1179 pregnant women, we determined serum YKL-40 four times during pregnancy (at gestational age 12, 20, 25, and 32 weeks). Pregnancy outcome was obtained from medical records. Sixty-eight women (5.8%) developed GDM. Serum YKL-40 increased from gestational age (GA) 12 weeks and the following weeks in the women who developed GDM and was independent of BMI, parity, and maternal age (OR = 2.69, 95% CI: 1.45-5.00, p = 0.002). No association was found between serum YKL-40 and the oral glucose tolerance test results. In conclusion, YKL-40 significantly increased in pregnant women with GDM compared with women without GDM, probably reflecting the low-grade inflammation of GDM. However, we did not find an association between serum concentrations of YKL-40 in early pregnancy and the development of GDM and thus we conclude that YKL-40 alone is not usable as a biomarker for early prediction of GDM.

YKL-40 in allogeneic hematopoietic cell transplantation after AML and myelodysplastic syndrome

YKL-40, also called chitinase-3-like-1 protein, is an inflammatory biomarker that has been associated with disease severity in inflammatory and malignant diseases, including AML, multiple myeloma and lymphomas. The objective of the current study was to assess the prognostic value of pretransplant recipient and donor plasma YKL-40 concentrations in patients with AML (n=624) or myelodysplastic syndrome (n=157) treated with allogeneic hematopoietic cell transplantation (HCT). In recipients, the plasma YKL-40 concentrations were increased when the HCT-comorbidity index was ⩾5 (P=0.028). There were no significant associations between plasma YKL-40 concentrations in recipients and any outcome measures. In donors with YKL-40 plasma concentrations above the age-adjusted 95th percentile, a trend toward increased grade II-IV acute GvHD in recipients was observed (adjusted hazard ratio 1.39 (95% confidence interval 1.00-1.94), P=0.050), with no significant associations with overall survival, treatment-related mortality or relapse. In conclusion, our study shows that YKL-40 does not aid risk stratification of patients undergoing allogeneic HCT, but suggests that YKL-40 may aid donor selection when multiple, otherwise equal, donors are available.

Glycoprotein YKL-40: a novel biomarker of chronic graft-vs-host disease activity and severity?

AIM

To investigate whether increased YKL-40 levels positively correlate with graft-vs-host disease (cGVHD) activity and severity and if YKL-40 could serve as a disease biomarker.

METHODS

This case-control study was conducted at the University Hospital Centre Zagreb from July 2013 to October 2015. 56 patients treated with hematopoietic stem cell transplantation (HSCT) were included: 35 patients with cGVHD and 21 without cGVHD. There was no difference between groups in age, sex, median time from transplant to study enrollment, intensity of conditioning, type of donor, or source of stem cells. Blood samples were collected at study enrollment and YKL-40 levels were measured with ELISA. Disease activity was estimated using Clinician's Impression of Activity and Intensity of Immunosuppression scales and disease severity using Global National Institutes of Health (NIH) score.

RESULTS

YKL-40 levels were significantly higher in cGVHD patients than in controls (P=0.003). The difference remained significant when patients with myelofibrosis were excluded from the analysis (P=0.017). YKL-40 level significantly positively correlated with disease severity (P<0.001; correlation coefficient 0.455), and activity estimated using Clinician's Impression of Activity (P=0.016; correlation coefficient 0.412) but not using Intensity of Immunosuppression (P=0.085; correlation coefficient 0.296).

CONCLUSION

YKL-40 could be considered a biomarker of cGVHD severity and activity. However, validation in a larger group of patients is warranted, as well as longitudinal testing of YKL-40 levels in patients at risk of developing cGVHD.

RIG-like Helicase Regulation of Chitinase 3-like 1 Axis and Pulmonary Metastasis

Chi3l1 is induced by a variety of cancers where it portends a poor prognosis and plays a key role in the generation of metastasis. However, the mechanisms that Chi3l1 uses to mediate these responses and the pathways that control Chi3l1-induced tumor responses are poorly understood. We characterized the mechanisms that Chi3l1 uses to foster tumor progression and the ability of the RIG-like helicase (RLH) innate immune response to control Chi3l1 elaboration and pulmonary metastasis. Here we demonstrate that RLH activation inhibits tumor induction of Chi3l1 and the expression of receptor IL-13Rα2 and pulmonary metastasis while restoring NK cell accumulation and activation, augmenting the expression of IFN-α/β, chemerin and its receptor ChemR23, p-cofilin, LIMK2 and PTEN and inhibiting BRAF and NLRX1 in a MAVS-dependent manner. These studies demonstrate that Chi3l1 is a multifaceted immune stimulator of tumor progression and metastasis whose elaboration and tissue effects are abrogated by RLH innate immune responses.

Diagnostic Value of Serum YKL-40 Level for Coronary Artery Disease: A Meta-Analysis

OBJECTIVE

This meta-analysis aimed to identify the value of serum YKL-40 level for the diagnosis of coronary artery disease (CAD).

METHODS

Through searching the following electronic databases: the Cochrane Library Database (Issue 12, 2013), Web of Science (1945 ∼ 2013), PubMed (1966 ∼ 2013), CINAHL (1982 ∼ 2013), EMBASE (1980 ∼ 2013), and the Chinese Biomedical Database (CBM; 1982 ∼ 2013), related articles were determined without any language restrictions. STATA statistical software (Version 12.0, Stata Corporation, College Station, TX) was chosen to deal with statistical data. Standard mean difference (SMD) and its corresponding 95% confidence interval (95% CI) were calculated.

RESULTS

Eleven clinical case-control studies that recruited 1,175 CAD patients and 1,261 healthy controls were selected for statistical analysis. The main findings of our meta-analysis showed that serum YKL-40 level in CAD patients was significantly higher than that in control subjects (SMD = 2.79, 95% CI = 1.73 ∼ 3.85, P < 0.001). Ethnicity-stratified analysis indicated a higher serum YKL-40 level in CAD patients than control subjects among China, Korea, and Denmark populations (China: SMD = 2.97, 95% CI = 1.21 ∼ 4.74, P = 0.001; Korea: SMD = 0.66, 95% CI = 0.17 ∼ 1.15, P = 0.008; Denmark: SMD = 1.85, 95% CI = 1.42 ∼ 2.29, P < 0.001; respectively), but not in Turkey (SMD = 4.52, 95% CI = -2.87 ∼ 11.91, P = 0.231).

CONCLUSION

The present meta-analysis suggests that an elevated serum YKL-40 level may be used as a promising diagnostic tool for early identification of CAD.

High CHI3L1 expression is associated with glioma patient survival

Background

Survival of glioma patients with the same tumor histology and grade can vary significantly, and some low-grade gliomas transform to a more malignant phenotype. There is a need of molecular signatures, which are better predictors of the patient diagnosis, outcome of treatment, and prognosis than the diagnosis provided by histopathology. We propose CHI3L1 mRNA expression as a prognostic biomarker for patients with glioma.

Methods

We measured CHI3L1 expression with quantitative real time-polymerase chain reaction (qRT-PCR) in the cohort of 98 patients with different grade glioma: 10 grade I pylocytic astrocytomas, 30 grade II diffuse astrocytomas, 20 grade III anaplastic astrocytomas, and 38 grade IV astrocytomas (glioblastomas). Statistical analyses were conducted to investigate the association between CHI3L1 mRNA expression levels and patient clinical variables.

Results

We demonstrated that mRNA expression of CHI3L1 was evidently higher in glioblastoma than in lower grade glioma tissues. We evaluated correlations between CHI3L1 expression, clinicopathological characteristics, and the outcomes of the patients. Patients with high CHI3L1 expression had a shorter overall survival (p < 0.001).

Conclusions

Findings presented in our study showed that increased mRNA level of CHI3L1 could be associated with the progression of astrocytoma and poor patient survival not only for glioblastoma, but for lower grade astrocytoma tumors as well. Further investigation will be required to evaluate CHI3L1 value as a molecular marker for astrocytoma prognoses and for novel treatment strategies against all grade astrocytomas.

Prognostic Value of YKL-40 in Patients with Glioblastoma: a Systematic Review and Meta-analysis

YKL-40 is the most highly expressed gene in glioblastoma compared with normal brain tissues. Previous studies assessing the association between YKL-40 and survival in glioblastoma patients reported varying magnitude of estimates. The objective of this meta-analysis was to determine the prognostic value of YKL-40 in glioblastoma patients. PubMed and Embase databases were searched for studies relating to YKL-40 and prognosis of glioblastoma patients. Studies reporting estimates for overall survival by YKL-40 expression in glioblastoma patients were considered eligible. A meta-analysis of included studies was performed using fixed- or random-effect model to calculate the pooled hazard ratio (HR) and 95 % confidence interval (95%CI). Eight studies were ultimately considered eligible and included into the meta-analysis. Those eight studies included 1241 glioblastoma patients. Meta-analysis of those studies showed that high YKL-40 expression was associated with worse overall survival in glioblastoma patients (HR = 1.46, 95%CI 1.33-1.61, P < 0.001). Meta-analysis of studies with adjusted estimates and high quality showed that high YKL-40 expression was independently associated with worse overall survival in glioblastoma patients (HR = 1.50, 95%CI 1.35-1.66, P < 0.001). Both subgroup analysis and sensitivity analysis validated the obvious association between high YKL-40 expression and worse overall survival in glioblastoma patients. High YKL-40 expression is independently and markedly associated with worse overall survival in glioblastoma patients. YKL-40 is a good predictive biomarker of prognosis in glioblastoma patients.

Clinical correlation between serum YKL-40 protein level and recurrence of non-muscle invasive bladder cancer

BACKGROUND

To explore the clinical correlation between serum YKL-40 protein level and recurrence of non-muscle invasive bladder cancer (NMIBC).

METHODS

Totally 76 NMIBC patients (including 34 patients with confirmed recurrence and 42 patients without recurrence during the 2-year post-operative follow-up) and 31 healthy volunteers were recruited in this study. Blood samples were collected early in the morning, and serum YKL-40 protein levels of all these patients were analysed by using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Serum YKL-40 protein levels were significantly higher in NMIBC patients than in healthy controls (P<0.001). Meanwhile, serum YKL-40 protein levels were found to be significantly higher in patients with recurrent NMIBC than those without tumor recurrence (P=0.001).

CONCLUSIONS

Serum YKL-40 protein can be a reliable molecular marker for the clinical diagnosis of NMIBC recurrence. In particular, it can inform the post-operative management.

Serum Markers of Epithelial Mesenchymal Transition as Predictors of HCV-induced Liver Fibrosis, Cirrhosis and Hepatocellular Carcinoma

Introduction

Hepatitis C virus (HCV) is a major cause of chronic liver disease in Egypt, leading to hepatic fibrosis, liver cirrhosis (LC), and hepatocellular carcinoma (HCC). Liver fibrosis is characterized by excessive deposition of extracellular matrix (ECM). Newly-recognized pathogenic mechanisms point to the epithelial-mesenchymal transition (EMT) of hepatocytes to matrix synthesizing (myo-) fibroblasts. Transforming growth factor-beta (TGF-β1), bone morphogenic protein (BMP)-7, and connective tissue growth factor (CTGF) are biomarkers reflecting the EMT process. YKL-40 is a glycoprotein member of ECM and plays a role in cancer cell proliferation. The purpose of this study was to determine the serum biomarkers of EMT and its impact on the fibrogenic process and tumorigenesis in HCV-genotype 4 patients.

Methods

In this case-control study that was conducted in 2013–2014, 97 HCV-infected patients were subjected to clinical examination, laboratory investigations, and liver biopsy. According to the histopathologic examination, they were classified to F0 (14 cases), F1 (17 cases), F2 (15 cases), F3 (18 cases), F4 (22 cases), and HCC (11 cases). Fifteen age- and gender-matched subjects were included as normal controls. Serum levels of TGF-β1, BMP-7, CTGF, YKL-40 were assessed, and the TGF-β1/BMP-7 ratios were calculated. The data were analyzed by plotting the receiver operating characteristic curve (ROC), Pearson product-moment correlation coefficient, and Spearman’s rank correlation coefficient (Spearman’s rho).

Results

Serum levels of TGF-β1, BMP-7, CTGF, and YKL-40 were significantly increased in all patient groups compared to controls (p < 0.001). LC exhibited the highest CTGF level and YKL-40 was highest in HCC. The TGF-β1/ BMP-7 ratios reflected the progression of EMT from CHC to LC, however, there was no significant difference between LC and HCC. TGF-β1/ BMP-7 ratio is considered to reflect positive correlation with CTGF in LC group (r = 0.629; p < 0.03) and YKL-40 in HCC group (r = 0.504; p < 0.04).

Conclusion

Increased TGF-β1/BMP-7 ratio and CTGF levels reflect the rate of EMT and provide information about fibrogenic activity. Also, this ratio, in association with YKL-40, can be used to predict malignant transformation in HCV-genotype 4 Egyptian patients.

Diagnostic and prognostic values of preoperative serum levels of YKL-40, HE-4 and DKK-3 in endometrial cancer

OBJECTIVE

The objective of this study is to determine the efficiency of YKL-40, HE-4 and DKK-3 levels in early diagnosis of patients with endometrial cancer and in the pre-operative estimation of the prognostic parameters such as stage, grade and the extension of the disease.

METHODS

In this prospective study, 50 patients diagnosed with endometrial cancer and 50 women as a control group, who applied to Dokuz Eylul University and Ege University Faculties of Medicine, Obstetrics and Gynecology Clinics between May 2011-May 2012 were included. CA125, HE-4, YKL-40 and DKK-3 serum levels were measured by ELISA and compared between two groups. The relation between serum levels and histopathological results, extension of disease and prognostic factors were analyzed.

RESULTS

Preoperative serum CA125, HE-4 and YKL-40 levels were significantly higher in endometrial cancer group (p<0.001). Serum HE-4 levels were significantly higher in advanced stages (p=0.004). When we examined early stage patients, YKL-40 levels were significantly higher in non-endometrioid histology compared with endometrioid adenocarcinoma (p=0.022). We also examined the relation between the markers and prognostic factors. Different from other markers, HE-4 levels were significantly higher in endometrial cancer patients who had lymphovascular space involvement, lower uterine segment involvement, endocervical stromal involvement, and deep myometrial invasion.

CONCLUSION

YKL-40 and HE-4 were significantly higher in patients with endometrial cancer. HE-4 seems to be superior to YKL-40 in discriminating early and advanced stages. Additionally, HE4 is significantly correlated with prognostic factors. HE-4 and YKL-40 may be successful in early determination of endometrial cancer and in detection of high risk subsets before surgery.

Inherited Inflammatory Response Genes Are Associated with B-Cell Non-Hodgkin's Lymphoma Risk and Survival

BACKGROUND

Malignant B-cell clones are affected by both acquired genetic alterations and by inherited genetic variations changing the inflammatory tumour microenvironment.

METHODS

We investigated 50 inflammatory response gene polymorphisms in 355 B-cell non-Hodgkin's lymphoma (B-NHL) samples encompassing 216 diffuse large B cell lymphoma (DLBCL) and 139 follicular lymphoma (FL) and 307 controls. The effect of single genes and haplotypes were investigated and gene-expression analysis was applied for selected genes. Since interaction between risk genes can have a large impact on phenotype, two-way gene-gene interaction analysis was included.

RESULTS

We found inherited SNPs in genes critical for inflammatory pathways; TLR9, IL4, TAP2, IL2RA, FCGR2A, TNFA, IL10RB, GALNT12, IL12A and IL1B were significantly associated with disease risk and SELE, IL1RN, TNFA, TAP2, MBL2, IL5, CX3CR1, CHI3L1 and IL12A were, associated with overall survival (OS) in specific diagnostic entities of B-NHL. We discovered noteworthy interactions between DLBCL risk alleles on IL10 and IL4RA and FL risk alleles on IL4RA and IL4. In relation to OS, a highly significant interaction was observed in DLBCL for IL4RA (rs1805010) * IL10 (rs1800890) (HR = 0.11 (0.02-0.50)). Finally, we explored the expression of risk genes from the gene-gene interaction analysis in normal B-cell subtypes showing a different expression of IL4RA, IL10, IL10RB genes supporting a pathogenetic effect of these interactions in the germinal center.

CONCLUSIONS

The present findings support the importance of inflammatory genes in B-cell lymphomas. We found association between polymorphic sites in inflammatory response genes and risk as well as outcome in B-NHL and suggest an effect of gene-gene interactions during the stepwise oncogenesis.

How to target small cell lung cancer

Small cell lung cancer (SCLC) is a highly malignant disease with dismal prognosis. Although great progress has been made in investigating genetic aberrations and putative drivers of this tumor entity, the mechanisms of rapid dissemination and acquisition of drug resistance are not clear. The majority of SCLC cases are characterized by inactivation of the tumor suppressors p53 and retinoblastoma (Rb) and, therefore, interchangeable drivers will be difficult to target successfully. Access to pure cultures of SCLC circulating tumor cells (CTCs) and study of their tumor biology has revealed a number of new potential targets. Most important, expression of chitinase-3-like-1/YKL-40 (CHI3L1) which controls expression of vascular epithelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP9) was newly described in these cells. The process switching CHI3L1-negative SCLC cells to CHI3L1-positive CTCs seems to be associated with cytokines released by inflammatory immune cells. Furthermore, these CTCs were found to promote monocyte-macrophage differentiation, most likely of the M2 tumor-promoting type, recently described to express PD-1 immune checkpoint antigen in SCLC. In conclusion, dissemination of SCLC seems to be linked to conversion of regular tumor cells to highly invasive CHI3L1-positive CTCs, which are protected by immune system suppression. Besides the classical targets VEGF, MMP-9 and PD-1, CHI3L1 constitutes a new possibly drugable molecule to retard down dissemination of SCLC cells, which may be similarly relevant for glioblastoma and other tumor entities.

Chitinase-3-like-1/YKL-40 as marker of circulating tumor cells

Ex vivo expansion of circulating tumor cells (CTCs) of small cell lung cancer (SCLC) patients enabled systematic screening of secreted cytokines. Permanent CTC cultures of different patients shared secretion of chitinase-3-like-1 (CHI3L1)/YKL-40, known to be upregulated in a range of tumor entities and to be associated with increased metastasis and decreased survival. This protein lacks enzymatic activity and its mechanism of promoting tumor dissemination has not been resolved. Results from SCLC CTC cultures suggest CHI3L1 as marker and important effector of tumor cell dissemination in the peripheral blood. Furthermore, this protein may link chronic inflammation of the lung, chronic obstructive pulmonary disease (COPD) and lung cancer.

Molecular prognostic factors in glioblastoma: state of the art and future challenges

Gliomas account for the majority of primary tumors of the CNS, of which glioblastoma (GBM) is the most common and malignant, and for which survival is very poor. Despite significant inter- and intra-tumor heterogeneity, all patients are treated with a standardized therapeutic approach. While some clinical features of GBM patients have already been established as classic prognostic factors (e.g., patient age at diagnosis and Karnofsky performance status), one of the most important research fields in neuro-oncology today is the identification of novel molecular determinants of patient survival and tumor response to therapy. Here, we aim to review and discuss some of the most relevant and novel prognostic biomarkers in adult and pediatric GBM patients that may aid in stratifying subgroups of GBMs and rationalizing treatment decisions.

Neutrophil-to-lymphocyte ratio, calprotectin and YKL-40 in patients with chronic obstructive pulmonary disease: correlations and 5-year mortality - a cohort study

Background

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and progressive decline in pulmonary function. Neutrophil-to-lymphocyte ratio (NLR), YKL-40 and calprotectin are biomarkers of inflammation and predict mortality in patients with different inflammatory diseases. We aimed to investigate the correlation between levels of these three biomarkers and neutrophil granulocyte and lymphocyte count in patients with moderate to very severe COPD stratified by use of systemic glucocorticoids. Furthermore, we studied the ability of these biomarkers to predict all-cause mortality.

Methods

386 patients with moderate to very severe COPD were followed prospectively for 10 years. Patients were divided into two groups according to systemic glucocorticoid use at baseline. Correlations between biomarkers were assessed by Spearman’s Rho, and mortality was evaluated in uni- and multivariate Cox regression analyses with hazard ratios (HR) and 95% confidence intervals (CI).

Results

Plasma calprotectin was positively correlated with neutrophil granulocyte count and NLR. No significant association was found between plasma YKL-40 and the cellular biomarkers, irrespective of glucocorticoid treatment. In the group not treated with systemic glucocorticoids, plasma calprotectin [HR 1.002 (95% CI 1.000 – 1.004)], NLR [HR 1.090 (1.036 – 1.148)] and lymphocyte count [HR 0.667 (0.522 – 0.851)] were significantly associated with higher mortality. In the group treated with systemic glucocorticoids, higher plasma YKL-40 was significantly associated with mortality in univariate Cox regression analysis [HR 1.006 (1.003 – 1.008)].

Conclusions

Calprotectin was related to neutrophil granulocyte count and NLR in patients with moderate to very severe COPD in stable phase and not in treatment with systemic glucocorticoids. Lymphopenia, higher plasma calprotectin and higher NLR were independent predictors of increased all-cause mortality in this group. Our data also suggests that treatment with systemic glucocorticoids has a significant impact on the ability of inflammatory biomarkers to predict all-cause mortality.

Trial registration

ClinicalTrials.gov NCT00132860.

Serum YKL-40: a new independent prognostic marker for skeletal complications in patients with multiple myeloma

In a time of increasing treatment options for multiple myeloma bone disease, risk factors predicting progression need to be elucidated. This study investigated the value of serum YKL-40, previously shown to be associated with radiographic progression of bone destruction, as a predictor for time to clinical progression, i.e. skeletal-related events (SREs), in 230 newly diagnosed patients with multiple myeloma receiving intravenous bisphosphonates. Serum concentrations of YKL-40 and biochemical bone markers (CTX-MMP, CTX-I, PINP) were measured at diagnosis. Patients were evaluated every third month for SRE and at 9 and 24 months for radiographic progression. Elevated serum YKL-40 was seen in 47% of patients and associated with high-risk disease (International Staging System stage III; p < 0.001), increased bone resorption (serum CTX/MMP; p < 0.001) and early radiographic progression at 9 months (p = 0.01). Serum YKL-40 together with serum CTX-MMP/PINP ratio and World Health Organization status were independent predictors of time to first SRE.

Serum YKL-40 in risk assessment for colorectal cancer: a prospective study of 4,496 subjects at risk of colorectal cancer

The aim of the present study was to test the hypothesis that high serum YKL-40 associates with colorectal cancer in subjects at risk of colorectal cancer. We measured serum YKL-40 in a prospective study of 4,496 Danish subjects [2,064 men, 2,432 women, median age 61 years (range, 18-97)] referred to endoscopy due to symptoms or other risk factors for colorectal cancer. Blood samples were collected just before large bowel endoscopy. Serum YKL-40 was determined by ELISA. Serum YKL-40 was higher (P < 0.0001, unadjusted for confounding covariates) in subjects diagnosed with colon cancer (median 126 μg/L, 25%-75%: 80-206 μg/L) and rectal cancer (104, 72-204 μg/L) compared with subjects with adenoma (84, 53-154 μg/L), other nonmalignant findings (79, 49-138 μg/L), and no findings (62, 41-109 μg/L). Serum YKL-40 independently predicted colorectal cancer [OR, 1.53; 95% confidence interval (CI), 1.40-1.67; AUC = 0.68, P < 0.0001]. Restricting the analysis to subjects with no comorbidity increased the OR for serum YKL-40 to predict colorectal cancer (OR, 1.82; 1.58-2.08; AUC = 0.73, P < 0.0001). Combining serum YKL-40 and CEA demonstrated that both were significant [(YKL-40, OR, 1.27; 95% CI, 1.16-1.40); (CEA, OR, 1.92; 1.75-2.10; AUC = 0.75, P < 0.0001; OR for a 2-fold difference in marker level)]. Multivariable analysis (YKL-40, CEA, age, gender, body mass index, and center) showed that serum YKL-40 was a predictor for colorectal cancer in individuals without comorbidity (OR, 1.25; 95% CI, 1.05-1.40; P = 0.012), whereas this was not the case for those with comorbidity (OR, 0.98; 95% CI, 0.84-1.14; P = 0.80). In conclusion, high serum YKL-40 in subjects suspected of colorectal cancer and without comorbidity associates with colorectal cancer. Determination of serum YKL-40 may be useful in combination with other biomarkers in risk assessment for colorectal cancer. Cancer Epidemiol Biomarkers Prev; 24(3); 621-6. ©2015 AACR.

Role of chitinase 3-like-1 and semaphorin 7a in pulmonary melanoma metastasis

The prototypic chitinase-like protein Chi3l1 is induced in cancers and portends a poor prognosis, but whether it contributes to cancer progression is unknown. To address this gap in knowledge, we investigated the production of Chi3l1 in melanoma lung metastases. We found that Chi3l1 was induced during pulmonary melanoma metastasis and that this induction was regulated by the semaphorin Sema7a, interacting in stimulatory or inhibitory ways with its β1 integrin or Plexin C1 receptors, respectively. In mouse strains with genetic deletions of Chi3l1 or Sema7a, there was a significant reduction in pulmonary metastasis. Notably, antiserum raised against Chi3l1 or Sema7a phenocopied the reduction produced by genetic deletions. Melanoma lung metastasis was also decreased in the absence of IL13Rα2, a recently identified receptor for Chi3l1, consistent with a key role for Chi3l1 in melanoma spread. We confirmed roles for Sema7a and Chi3l1 in pulmonary metastasis of EMT6 breast cancer cells. Taken together, our studies establish a novel pathway through which Sem7a and its receptors regulate Chi3l1, revealing a host axis involving IL13Rα2 that plays a critical role in generating a pulmonary microenvironment that is critical to license metastasis.

Plasma YKL-40 in Inuit and Danes

AIMS

The aim of the present study was to investigate whether there are differences in plasma levels of YKL-40 between Inuit in Greenland and in Denmark and in Danes, as well as to study the relationship between alcohol intake, plasma YKL-40 and other factors in Inuit.

METHODS

Plasma YKL-40 levels were measured on 1645 people from The Greenland Population Study (a cross-sectional population study of Inuit from Denmark and West Greenland) and were compared with the plasma YKL-40 levels of 8899 people from The Copenhagen City Heart Study (a population-based, prospective study of the Danish general population).

RESULTS

The plasma concentrations of YKL-40 were significantly (P = 0.001) lower in Inuit living in Greenland (median 46 µg/l, range 10-2164, n = 1164) compared with the plasma YKL-40 levels of Inuit living in Denmark (median 63 µg/l, range 20-2827, n = 481) and of Danes living in Denmark (median 55 µg/l, range 10-2909, n = 8899). In Inuit, increased alcohol intake was significantly associated with increased plasma YKL-40 levels (P < 0.001), and high plasma YKL-40 levels were associated with high values of alkaline phosphatase and low values of albumin. Smoking, gender and bilirubin were not associated with the plasma YKL-40 level. High levels of YKL-40 and alcohol were associated with where people lived.

CONCLUSION

The plasma concentrations of YKL-40 are significantly lower in Inuit living in Greenland than Inuit and Danes living in Denmark. A number of factors, including different alcohol intake patterns, nutrition and genes may play a role in these findings.

New treatment and markers of prognosis for idiopathic pulmonary fibrosis: lessons learned from translational research

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease with increasing prevalence, high mortality rates and poor treatment options. The diagnostic process is complex and often requires an interdisciplinary approach between different specialists. Information gained over the past 10 years of intense research resulted in improved diagnostic algorithms, a better understanding of the underlying pathogenesis and the development of new therapeutic options. Specifically, the change from the traditional concept that viewed IPF as a chronic inflammatory disorder to the current belief that is primarily resulting from aberrant wound healing enabled the identification of novel treatment targets. This increased the clinical trial activity dramatically and resulted in the approval of the first IPF-specific therapy in many countries. Still, the natural history and intrinsic behavior of IPF are very difficult to predict. There is an urgent need for new therapies and also for development and validation of prognostic markers that predict disease progression, survival and also response to antifibrotic drugs. This review provides an up to date summary of the most relevant clinical trials, novel therapeutic drug targets and outlines a spectrum of potential prognostic biomarkers for IPF.

Elevated YKL40 is associated with advanced prostate cancer (PCa) and positively regulates invasion and migration of PCa cells

Chitinase 3-like 1 (CHI3L1 or YKL40) is a secreted glycoprotein highly expressed in tumours from patients with advanced stage cancers, including prostate cancer (PCa). The exact function of YKL40 is poorly understood, but it has been shown to play an important role in promoting tumour angiogenesis and metastasis. The therapeutic value and biological function of YKL40 are unknown in PCa. The objective of this study was to examine the expression and function of YKL40 in PCa. Gene expression analysis demonstrated that YKL40 was highly expressed in metastatic PCa cells when compared with less invasive and normal prostate epithelial cell lines. In addition, the expression was primarily limited to androgen receptor-positive cell lines. Evaluation of YKL40 tissue expression in PCa patients showed a progressive increase in patients with aggressive disease when compared with those with less aggressive cancers and normal controls. Treatment of LNCaP and C4-2B cells with androgens increased YKL40 expression, whereas treatment with an anti-androgen agent decreased the gene expression of YKL40 in androgen-sensitive LNCaP cells. Furthermore, knockdown of YKL40 significantly decreased invasion and migration of PCa cells, whereas overexpression rendered them more invasive and migratory, which was commensurate with an enhancement in the anchorage-independent growth of cells. To our knowledge, this study characterises the role of YKL40 for the first time in PCa. Together, these results suggest that YKL40 plays an important role in PCa progression and thus inhibition of YKL40 may be a potential therapeutic strategy for the treatment of PCa.

Electrochemical detection of the disease marker human chitinase-3-like protein 1 by matching antibody-modified gold electrodes as label-free immunosensors

Tissue inflammation, certain cardiovascular syndromes and the occurrence of some solid tumors are correlated with raised serum concentrations of human chitinase-3-like protein 1 (YKL-40), a mammalian chitinase-like glycoprotein, which has become the subject of current research. Here we report the construction and characterization of an electrochemical platform for label-free immunosensing of YKL-40. Details of the synthesis of YKL-40 and production of anti-YKL-40 immunoglobulin G (IgG) are provided and cross-reactivity tests presented. Polyclonal anti-YKL-40 IgG was immobilized on gold electrodes and the resulting immunosensors were operated in an electrochemical flow system with capacitive signal generation. The strategy offered a wide linear detection range (0.1μg/L to 1mg/L) with correlation coefficients (R(2)) above 0.99 and good sensitivity (12.28±0.27nF/cm(2) per decade of concentration change). Additionally, the detection limit of 0.07±0.01μg/L was well below that of optical enzyme-linked immunosorbent assays (ELISAs), which makes the proposed methodology a promising alternative for YKL-40 related disease studies.

Serum YKL-40 and uterine artery Doppler -- a prospective cohort study, with focus on preeclampsia and small-for-gestational-age

OBJECTIVE

To test if serum YKL-40 is increased in women developing preeclampsia or small-for-gestational age fetuses. We also assessed the association between uterine artery pulsatility index, notching and serum YKL-40 levels.

DESIGN

Prospective cohort study.

SETTING

A primary referral unit for obstetric ultrasound.

POPULATION

A total of 1214 unselected pregnant women enrolled at nuchal translucency examination between 11(+3) and 13(+6)  weeks of gestation.

METHODS

All women had ultrasound and blood sample collection at the nuchal translucency scan, a 20-week malformation scan and 25-week and 32-week fetal growth examinations. Uterine artery Doppler was assessed and outcome was registered from medical records.

MAIN OUTCOME MEASURES

Preeclampsia, hypertension, small-for-gestational age.

RESULTS

Serum YKL-40 was associated with increasing maternal age (p < 0.0001), body mass index (p = 0.0002), primiparity (p = 0.0003), and hypertension (p = 0.015). Serum YKL-40 increased from 12 to 20 weeks and decreased from 20-25 and 25-32 weeks of gestation. No association was found between preeclampsia and serum YKL-40. Small-for-gestational-age at birth was significantly associated with a 5.4% increase in serum YKL-40 at 32 weeks of gestation (95% CI 1.5-9.3, p = 0.005). An association was found between uterine artery pulsatility index at 32 weeks and small-for-gestational age (p = 0.0015) but not between YKL-40 and uterine artery notching (p = 0.83).

CONCLUSIONS

Serum YKL-40 was not associated with preeclampsia. Increasing serum YKL-40 was related to maternal age, body mass index and small-for-gestational age and may reflect an exaggerated inflammatory response.

Simulating tumor microenvironment: changes in protein expression in an in vitro co-culture system

BACKGROUND

The role of the microenvironment during the initiation and progression of carcinogenesis is thought to be of critical importance, both for the enhanced understanding of fundamental cancer biology as well as for improving molecular diagnostics and therapeutics. The aim of this study was to establish an in vitro model based on a co-culture of healthy human fibroblasts (HFs) and human osteosarcoma cells (MG-63s) to simulate the microenvironment including tumor and healthy cells.

METHODS

The HFs and MG-63s were in vitro co-cultured for a period of time ranging from 24 h to 7 days. Cell morphology and organization were studied using phase contrast microscopy while the expression of Human Cartilage Glycoprotein 39 (YKL-40), Vascular Endothelial Growth Factor (VEGF) and Matrix Metalloprotease 1 (MMP1) was investigated by Real Time PCR and Western Blotting.

RESULTS

The results showed a characteristic disposition of tumor and healthy co-cultured cells in columns which are not visible in tumor and healthy cells grown singularly. The expression of YKL-40, VEGF and MMP1 significantly changed in co-cultured cells compared to HFs and MG-63s separately cultured.

CONCLUSIONS

We concluded that the tumor microenvironment has an influence on the protein expression of the healthy surrounding tissues and the process of tumorigenicity.

Antibody directed against human YKL-40 increases tumor volume in a human melanoma xenograft model in scid mice

Induced overexpression of the secretory protein YKL-40 promotes tumor growth in xenograft experiments. We investigated if targeting YKL-40 with a monoclonal antibody could inhibit tumor growth. YKL-40 expressing human melanoma cells (LOX) were injected subcutenously in Balb/c scid mice. Animals were treated with intraperitoneal injections of anti-YKL-40, isoptype control or PBS. Non-YKL-40 expressing human pancreatic carcinoma cell line PaCa 5061 served as additional control. MR imaging was used for evaluation of tumor growth. Two days after the first injections of anti-YKL-40, tumor volume had increased significantly compared with controls, whereas no effects were observed for control tumors from PaCa 5061 cells lacking YKL-40 expression. After 18 days, mean tumor size of the mice receiving repeated anti-YKL-40 injections was 1.82 g, >4 times higher than mean tumor size of the controls (0.42 g). The effect of anti-YKL-40 on the increase of tumor volume started within hours after injection and was dose dependent. Intratumoral hemorrhage was observed in the treated animals. The strong effect on tumor size indicates important roles for YKL-40 in melanoma growth and argues for a careful evaluation of antibody therapy directed against YKL-40.

YKL-40 expression in soft-tissue sarcomas and atypical lipomatous tumors. An immunohistochemical study of 49 tumors

BACKGROUND AND PURPOSE

YKL-40 is a glycoprotein that is expressed in many types of cancer cells. In some cancers, there is a correlation between high serum YKL-40 levels on the one hand and more aggressive disease and early death on the other. YKL-40 has never been studied in patients with soft-tissue sarcomas (STSs). We investigated whether YKL-40 is expressed in STS tissue and ascertained that the degree of expression is related to survival and/or the histological grade of the malignancy (FNCLCC).

PATIENTS AND METHODS

We included archived tissue from 49 patients (40 with STS and 9 with atypical lipomatous tumor, 20 female and 29 male, mean age 58 (4-89) years) who were treated with tumor resection in 2004 or 2005 at the Department of Orthopedics, Rigshospitalet. The minimum length of follow-up with respect to survival was 5-7 years. Immunohistochemical analysis with anti-YKL-40 antibody using tissue microarray was performed on resected tumors, and a semiquantitative measure of the intensity of YKL-40 staining was performed.

RESULTS

41 of the 49 tumors were positive for YKL-40, and of these, 36 had moderate to intense staining. 24 of the patients died within the follow-up period, and the intensity of YKL-40 staining was significantly higher in tumors from patients who had died in the follow-up period than in tumors from those who survived (p = 0.01). The staining intensity was different for the 3 grades of malignancy (p = 0.004): it was higher in highly malignant tumors (FNCLCC grade 2 and grade 3) than in low-malignancy tumors (grade 1).

INTERPRETATION

YKL-40 is expressed in soft-tissue sarcomas. There is a correlation between expression of YKL-40 in STS and both histological grade of the malignancy and survival. Whether or not YKL-40 expression is an independent prognostic variable could not be determined in the present study.

Role of tumor associated macrophages in tumor angiogenesis and lymphangiogenesis

Tumor angiogenesis is an essential process for supplying rapidly growing malignant tissues with essential nutrients and oxygen. An angiogenic switch allows tumor cells to survive and grow, and provides them access to vasculature resulting in metastatic disease. Monocyte-derived macrophages recruited and reprogrammed by tumor cells serve as a major source of angiogenic factors boosting the angiogenic switch. Tumor endothelium releases angiopoietin-2 and further facilitates recruitment of TIE2 receptor expressing monocytes (TEM) into tumor sites. Tumor-associated macrophages (TAM) sense hypoxia in avascular areas of tumors, and react by production of angiogenic factors such as VEGFA. VEGFA stimulates chemotaxis of endothelial cells (EC) and macrophages. In some tumors, TAM appeared to be a major source of MMP9. Elevated expression of MMP9 by TAM mediates extracellular matrix (ECM) degradation and the release of bioactive VEGFA. Other angiogenic factors released by TAM include basic fibroblast growth factor (bFGF), thymidine phosphorylase (TP), urokinase-type plasminogen activator (uPA), and adrenomedullin (ADM). The same factors used by macrophages for the induction of angiogenesis [like vascular endothelial growth factor A (VEGF-A) and MMP9] support lymphangiogenesis. TAM can express LYVE-1, one of the established markers of lymphatic endothelium. TAM support tumor lymphangiogenesis not only by secretion of pro-lymphangiogenic factors but also by trans-differentiation into lymphatic EC. New pro-angiogenic factor YKL-40 belongs to a family of mammalian chitinase-like proteins (CLP) that act as cytokines or growth factors. Human CLP family comprises YKL-40, YKL-39, and SI-CLP. Production of all three CLP in macrophages is antagonistically regulated by cytokines. It was recently established that YKL-40 induces angiogenesis in vitro and in animal tumor models. YKL-40-neutralizing monoclonal antibody blocks tumor angiogenesis and progression. The role of YKL-39 and SI-CLP in tumor angiogenesis and lymphangiogenesis remains to be investigated.

Brain barriers and a subpopulation of astroglial progenitors of developing human forebrain are immunostained for the glycoprotein YKL-40

YKL-40, a glycoprotein involved in cell differentiation, has been associated with neurodevelopmental disorders, angiogenesis, neuroinflammation and glioblastomas. We evaluated YKL-40 protein distribution in the early human forebrain using double-labeling immunofluorescence and immunohistochemistry. Immunoreactivity was detected in neuroepithelial cells, radial glial end feet, leptomeningeal cells and choroid plexus epithelial cells. The subpial marginal zone was YKL-40-positive, particularly in the hippocampus, from an early beginning stage in its development. Blood vessels in the intermediate and subventricular zones showed specific YKL-40 reactivity confined to pericytes. Furthermore, a population of YKL-40-positive, small, rounded cells was identified in the ventricular and subventricular zones. Real-time quantitative RT-PCR analysis showed strong YKL-40 mRNA expression in the leptomeninges and the choroid plexuses, and weaker expression in the telencephalic wall. Immunohistochemistry revealed a differential distribution of YKL-40 across the zones of the developing telencephalic wall. We show that YKL-40 is associated with sites of the brain barrier systems and propose that it is involved in controlling local angiogenesis and access of peripheral cells to the forebrain via secretion from leptomeningeal cells, choroid plexus epithelium and pericytes. Furthermore, we suggest that the small, rounded, YKL-40-positive cells represent a subpopulation of astroglial progenitors, and that YKL-40 could be involved in the differentiation of a particular astrocytic lineage.

Airway, but not serum or urinary, levels of YKL-40 reflect inflammation in early cystic fibrosis lung disease

BACKGROUND

Cystic fibrosis (CF) lung disease begins in early life and is progressive with the major risk factor being an exaggerated inflammatory response. Currently, assessment of neutrophilic inflammation in early cystic fibrosis (CF) lung disease relies on bronchoalveolar lavage (BAL). The chitinase-like protein YKL-40 is raised in sputum and serum of adults with CF. We investigated YKL-40 in BAL, serum and urine to determine whether this reflected inflammation and infection in young children with CF.

METHODS

YKL-40 was measured in matched samples of BAL, serum and urine obtained from 36 infants and young children with CF participating in an early surveillance program. Levels were compared to clinical data and markers of inflammation detected in the lung.

RESULTS

YKL-40 in BAL correlated with pulmonary infection [β=1.30 (SE 0.34), p < 0.001] and BAL markers of inflammation [macrophage number: r2 = 0.34, p < 0.001; neutrophil number: r2 = 0.74, p < 0.001; neutrophil elastase: r2 = 0.47, p < 0.001; CXCL8: r2 = 0.45, p < 0.001; IL-β: r2 = 0.62, p < 0.001]. YKL-40 was detectable in serum but levels did not correlate with BAL levels in the same individuals (r2 = 0.04, p = 0.14) or with inflammatory markers. YKL-40 was below the limit of detection in urine (30 pg/ml).

CONCLUSIONS

This study demonstrates that levels of the chitinase-like protein YKL-40 reflect airway inflammation and infection in early CF lung disease. The lack of increased YKL-40 in serum in the absence of systemic inflammation limits the benefit of this potential biomarker in early disease.

Plasma YKL-40 in patients with metastatic colorectal cancer treated with first line oxaliplatin-based regimen with or without cetuximab: RESULTS from the NORDIC VII Study

Background

We aim to test the hypothesis that high plasma YKL-40 is associated with short progression-free survival (PFS) and overall survival (OS) in patients with metastatic colorectal cancer (mCRC) treated with first-line oxaliplatin and 5-flourouracil with or without cetuximab.

Patients and Methods

A total of 566 patients in the NORDIC VII Study were randomized 1∶1∶1 to arm A (Nordic FLOX), arm B (Nordic FLOX + cetuximab), or arm C (Nordic FLOX + cetuximab for 16 weeks followed by cetuximab alone as maintenance therapy). Pretreatment plasma samples were available from 510 patients. Plasma YKL-40 was determined by ELISA and dichotomized according to the age-corrected 95% YKL-40 level in 3130 healthy subjects.

Results

Pretreatment plasma YKL-40 was elevated in 204 patients (40%), and median YKL-40 was higher in patients with mCRC than in healthy subjects (age adjusted, P<0.001). Patients with elevated YKL-40 had shorter PFS than patients with normal YKL-40 (7.5 vs. 8.2 months; hazard ratio (HR)  = 1.27 95% confidence interval (CI) 1.05–1.53 P = 0.013) and shorter OS (16.8 vs. 23.9 months; HR = 1.33, 1.04–1.69, P = 0.024). Multivariate Cox analysis demonstrated that elevated pretreatment YKL-40 was an independent biomarker of short OS (HR = 1.12, 1.01–1.25, P = 0.033). The ratio of the updated plasma YKL-40 (i.e. level after 1, 2, 8 weeks of treatment, and at end of treatment compared to the baseline level) was associated with OS (HR = 1.27, 1.06–1.52, P = 0.011).

Conclusions

Plasma YKL-40 is an independent prognostic biomarker in patients with mCRC treated with first-line oxaliplatin-based therapy alone or combined with cetuximab.

Plasma YKL-40 and all-cause mortality in patients with chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is hallmarked by inflammatory processes and a progressive decline of lung function. YKL-40 is a potential biomarker of inflammation and mortality in patients suffering from inflammatory lung disease, but its prognostic value in patients with COPD remains unknown. We investigated whether high plasma YKL-40 was associated with increased mortality in patients with moderate to very severe COPD.

METHODS

Four hundred and ninety-three patients with moderate to very severe COPD were followed prospectively for up to 10 years. Patients were divided into two groups according to plasma YKL-40: concentration higher than the 75th percentile for age-matched healthy subjects (i.e. high levels) and normal levels. Outcome was overall survival (OS) and was evaluated in uni- and multivariate proportional hazards Cox regression analyses and adjusted for factors affecting mortality.

RESULTS

Median plasma YKL-40 was increased in patients with COPD (81 ng/ml, p < 0.001) compared to healthy subjects (40 ng/ml). Patients with high plasma YKL-40 had a hazard ratio (HR) of 1.42 (95% CI: 1.15-1.75, p = 0.001) for all-cause mortality. Multivariate analysis showed that YKL-40 (HR 1.38; 95% CI: 1.11-1.72, p = 0.004), age (HR 1.05; 95% CI: 1.03-1.06, p < 0.0001), Severe COPD (HR 1.35; 95 CI: 1.03-1.76, p = 0.03) very severe COPD (HR 2.19; 95% CI: 1.60 - 2.99 < 0.0001), neutrophil granulocyte count (HR 1.05; 95% CI: 1.01-1.08, p = 0.01), and a smoking history of > 40 years (HR 1.38; 95% CI: 1.11-1.71, p = 0.003) were independent prognostic markers of OS.

CONCLUSION

High plasmaYKL-40 is associated with increased mortality in patients with moderate to very severe COPD, suggesting a role for YKL-40 as a potential biomarker of mortality in this patient group.

Usefulness of plasma YKL-40 in management of community-acquired pneumonia severity in patients

Plasma YKL-40 level has been reported as playing a significant role in community-acquired pneumonia (CAP). However, the correlation between plasma level of YKL-40 and the severity of CAP has not been reported. This study identifies the relationship between plasma level changes of the YKL-40 gene in adult patients hospitalized with CAP. The ELISA was used to measure the plasma YKL-40 level from 61 adult CAP patients before and after antibiotic treatment and from 60 healthy controls. The plasma YKL-40 levels were significantly increased in patients with CAP compared to normal controls. Moreover, the plasma concentration of YKL-40 correlated with the severity of CAP based on the pneumonia severity index (PSI) score (r = 0.630, p < 0.001), the CURB-65 (confusion, uremia, respiratory rate, BP, age 65 years) score (r = 0.640, p < 0.001), the Acute Physiology And Chronic Health Evaluation II (APACHE II) score (r = 0.539, p < 0.001) and length of hospital stay (r = 0.321, p = 0.011), respectively. In conclusion, plasma YKL-40 may play a role in the diagnosis and clinical assessment of CAP severity, which could potentially guide the development of treatment strategies.

A novel biomarker-based analysis reliably predicts nodal metastases in anal carcinoma: preliminary evidence of therapeutic impact

AIM

Routine prophylactic inguinal irradiation in anal cancer may cause significant toxicity associated with overtreatment bias. The aim of this study was to determine the risk of regional node metastases in anal carcinoma by identifying predictive molecular biomarkers.

METHOD

Clinicohistopathological data from 50 pretreatment anal carcinoma biopsies were collected. Immunohistochemical analyses with antibodies against Ki67, p53, epidermal growth factor receptor (EGFR) and YKL-40 were performed. Statistical correlations between biomarkers and clinicopathological features and outcomes were studied. Sentinel lymph node biopsy was performed in a subset of 36 patients.

RESULTS

All patients had undergone synchronous radiochemotherapy; tumour recurrence had developed in 26%, and 16% had died. YKL-40 tumour expression correlated with lymph node metastasis, whereas no inguinal node metastases were found in any of the (14%) patients presenting with a YKL-40/EGFR-negative tumour. YKL-40 expression and node metastasis were both significantly associated with shorter overall and disease-free survival. Tumour grade significantly correlated with disease-free survival only. HIV, tumour histological type, Ki67, p53 and EGFR were not associated with outcome.

CONCLUSION

YKL-40 expression in anal carcinoma is correlated with a poor outcome and can predict lymph node metastases. The combined absence of YKL-40 and EGFR expression in a first biopsy of anal carcinoma reliably selects a subset of patients without inguinal metastases. Such patients could be spared sentinel lymph node biopsy and/or inguinal radiotherapy.

Genetic variants in CHI3L1 influencing YKL-40 levels: resequencing 900 individuals and genotyping 9000 individuals from the general population

BACKGROUND

Despite its important role in many serious diseases, the genetic background for plasma YKL-40 has still not been systematically catalogued. Therefore, we aimed at identifying genetic variants in CHI3L1 influencing plasma YKL-40 levels in the general population.

METHODS

We resequenced the promoter, all 10 exons and exon-flanking intron segments of CHI3L1 in 904 individuals from the Danish general population (n=8899) with extreme plasma YKL-40 levels, adjusted for age. To potentially identify clinically important genetic variants with elevated plasma YKL-40 levels, we included twice as many individuals with the highest plasma YKL-40 levels (n=603) compared with the lowest plasma YKL-40 levels (n=301). Next, we mapped linkage disequilibrium for all variants with a minor allele frequency (MAF)>0.005. Finally, all participants were genotyped for eight variants that had divergent MAFs in the two extreme plasma YKL-40 groups.

RESULTS

We identified 59 genetic variants in CHI3L1. Fifteen of the genetic variants were associated with plasma YKL-40 levels. Three promoter SNPs, 1 non-synonymous SNP, and four intronic SNPs in CHI3L1 were associated with plasma YKL-40 levels at or below genome-wide association significance levels (unadjusted p for trend: from 4 × 10(-8) to 6 × 10(-243); age adjusted percentiles p for trend: from 3 × 10(-12) to 2 × 10(-304)).

CONCLUSIONS

In a systematic search to identify genetic variants influencing plasma YKL-40 levels, we identified eight SNPs associated with plasma YKL-40 levels in the general population.

Evaluation of CHI3L-1 and CHIT-1 expression in differentiated and polarized macrophages

Chitinase 3-like protein 1 (CHI3L-1) and chitotriosidase (CHIT-1) are members of the chitinase family. CHI3L-1 is a newly recognized protein that is secreted by activated macrophages and neutrophils and expressed in a broad spectrum of inflammatory conditions and cancers. In human plasma, CHIT-1 activity has been proposed as a biochemical marker of macrophage activation. Although CHI3L-1 expression in inflammation is under examination, little is known regarding its regulation during macrophages' full maturation and polarization. In this study, we compared CHI3L-1 and CHIT-1 modulation during monocyte to macrophage transition and polarization. Gene expression analysis was investigated by real-time PCR. We found that during the maturation of monocytes into macrophages, the expression of both CHI3L-1 and CHIT-1 increased exponentially over time. Additionally, we observed a different regulation of CHI3L-1 and CHIT-1 in undifferentiated monocytes under stimulation with lipopolysaccharide, interferon-γ, and interleukin-4, at the same concentration used to polarize macrophages. Our finding suggests that in the immune response, the role of CHI3L-1 and CHIT-1 is not restricted to innate immunity, but they are also protagonists in acquired immunity.

Diagnostic and Prognostic Impact of Circulating YKL-40, IL-6, and CA 19.9 in Patients with Pancreatic Cancer

Purpose

We tested the hypothesis that high plasma YKL-40 and IL-6 associate with pancreatic cancer and short overall survival.

Patients and Methods

In all, 559 patients with pancreatic cancer from prospective biomarker studies from Denmark (n = 448) and Germany (n = 111) were studied. Plasma YKL-40 and IL-6 were determined by ELISAs and serum CA 19.9 by chemiluminescent immunometric assay.

Results

Odds ratios (ORs) for prediction of pancreatic cancer were significant for all biomarkers, with CA 19.9 having the highest AUC (CA 19.9: OR = 2.28, 95% CI 1.97 to 2.68, p<0.0001, AUC = 0.94; YKL-40: OR = 4.50, 3.99 to 5.08, p<0.0001, AUC = 0.87; IL-6: OR = 3.68, 3.08 to 4.44, p<0.0001, AUC = 0.87). Multivariate Cox analysis (YKL-40, IL-6, CA 19.9, age, stage, gender) in patients operated on showed that high preoperative IL-6 and CA 19.9 (dichotomized according to normal values) were independently associated with short overall survival (CA 19.9: HR = 2.51, 1.22–5.15, p = 0.013; IL-6: HR = 2.03, 1.11 to 3.70, p = 0.021). Multivariate Cox analysis of non-operable patients (Stage IIB-IV) showed that high pre-treatment levels of each biomarker were independently associated with short overall survival (YKL-40: HR = 1.30, 1.03 to 1.64, p = 0.029; IL-6: HR = 1.71, 1.33 to 2.20, p<0.0001; CA 19.9: HR = 1.54, 1.06 to 2.24, p = 0.022). Patients with preoperative elevation of both IL-6 and CA 19.9 had shorter overall survival (p<0.005) compared to patients with normal levels of both biomarkers (45% vs. 92% alive after 12 months).

Conclusions

Plasma YKL-40 and IL-6 had less diagnostic impact than CA 19.9. Combination of pretreatment YKL-40, IL-6, and CA 19.9 may have clinical value to identify pancreatic cancer patients with the poorest prognosis.

YKL-40 acts as an angiogenic factor to promote tumor angiogenesis

A secreted glycoprotein YKL-40 also named chitinase-3-like-1 is normally expressed by multiple cell types such as macrophages, chondrocytes, and vascular smooth muscle cells. However, a prominently high level of YKL-40 was found in a wide spectrum of human diseases including cancers and chronic inflammatory diseases where it was strongly expressed by cancerous cells and infiltrating macrophages. Here, we summarized recent important findings of YKL-40 derived from cancerous cells and smooth muscle cells during tumor angiogenesis and development. YKL-40 is a potent angiogenic factor capable of stimulating tumor vascularization mediated by endothelial cells and maintaining vascular integrity supported by smooth muscle cells. In addition, YKL-40 induces FAK-MAPK signaling and up-regulates VEGF receptor 2 in endothelial cells; but a neutralizing antibody (mAY) against YKL-40 inhibits its angiogenic activity. While YKL-40 is essential for angiogenesis, little is known about its functional role in tumor-associated macrophage (TAM)-mediated tumor development. Therefore, significant efforts are urgently needed to identify pathophysiological function of YKL-40 in the dynamic interaction between tumor cells and TAMs in the tumor microenvironment, which may offer substantial mechanistic insights into tumor angiogenesis and metastasis, and also point to a therapeutic target for treatment of cancers and other diseases.

Plasma YKL-40 and CHI3L1 in systemic inflammation and sepsis-experience from two prospective cohorts

YKL-40, derived from the CHI3L1 gene, has been associated with outcome of infectious and inflammatory diseases. We hypothesized that plasma YKL-40 concentrations and CHI3L1 genotype could be used as prognostic biomarkers in the assessment of systemic inflammatory response syndrome (SIRS) and sepsis. The objective of the study was to assess the prognostic value of plasma YKL-40 and CHI3L1 genotype in patients with SIRS and sepsis. Plasma YKL-40 and CHI3L1 genotype (rs4950928) were analyzed at time of admission to intensive care units (ICU), in two prospective cohorts of consecutive SIRS patients (cohort 1, n=272; cohort 2, n=502). The plasma YKL-40 cut-off for predicting survival was determined in cohort 1 by receiver operator characteristic analyses and validated in cohort 2. In cohort 1 patients with plasma YKL-40 ≤505ng/ml (area under the curve 0.64 (95% confidence interval (CI) 0.57-0.70), p<0.001, sensitivity 53%, specificity 76%) had superior day 90 survival (81% vs. 55%, p<0.001, hazard ratio (HR) 2.29 (95% CI 1.29-4.07)). In the second cohort plasma YKL-40 ≤505ng/ml was also associated with superior survival (61% vs. 38%, p<0.001, HR 1.43 (1.03-1.99)). CHI3L1 minor allele homozygosity was associated with low plasma YKL-40 at time of admission (p=0.002) and no variation (p=0.462) in concentrations throughout the first 14 days in the ICU, but this was not associated with better survival. In conclusion patients with SIRS and sepsis, plasma YKL-40 ≤505ng/ml at time of ICU admission was associated with better survival. However, this association was not observed for patients homozygous for the low expressing YKL-40 CHI3L1 allele.

Significant association of elevated concentration of plasma YKL-40 with disease severity in patients with pelvic inflammatory disease

INTRODUCTION

To date, no study reports the implication of YKL-40 in pelvic inflammatory disease (PID). Therefore, we investigate the levels of plasma YKL-40 in patients with PID and further associate its expression with the severity of disease.

METHODS

We designed a hospital-based case-control study with approximate 1:1 ratio and consecutively recruited 64 patients with PID and 70 control women. We collected blood samples from 64 women with PID before and after they received treatment and 70 control women to detect levels of plasma YKL-40 and C-reactive protein (CRP) as well as white blood cell and neutrophil counts.

RESULTS

The results revealed that levels of plasma YKL-40 were significantly elevated in patients with PID as compared to those in controls (38.36 vs. 21.69 ng/ml, P = 0.001) but the significant difference was restricted to women aged 30 years or old after age stratification (56.75 vs. 23.61 ng/ml, P ≤ 0.001). It declined significantly after they received treatment (median: 38.36 vs. 27.54 ng/ml; P ≤ 0.001). Although both plasma YKL-40 and CRP were elevated in patients with tubo-ovarian abscess, PID patients with surgery exhibited higher YKL-40 concentration than those without surgery (median: 82.05 vs. 30.19 ng/ml, P = 0.005) and only plasma YKL-40 was significantly associated with the length of the hospital stay (P ≤ 0.001, R = 0.604).

CONCLUSION

We conclude that once individuals are diagnosed to have PID, YKL-40 may act as a biomarker to predict the severity and clinical outcome of the disease.

High YKL-40 serum concentration is correlated with prognosis of Chinese patients with breast cancer

This study aimed to investigate the association between serum YKL-40 and prognosis of breast cancer in a Chinese population. Expression of YKL-40 of 120 Chinese patients with breast cancer and 30 controls (benign breast lesions) was measured in tumor tissue by immunohistochemistry and in serum by ELISA. Differences in YKL-40 positivity grouped by specific patients' characteristics were compared using Pearson Chi-square test for rates of intratumoral staining, one-way ANOVA with a Bonferroni post-hoc comparison, or two-sample t-test for mean YKL-40 serum concentrations. Factors associated with overall survival were identified by univariate and multivariate cox-regression analyses. YKL-40 was elevated in approximately 75% of Chinese patients with breast cancer. A significantly higher percentage of patients with YKL-40 positive tumors had larger tumor size, higher TNM stage, and/or lymph node metastasis. Significantly higher mean YKL-40 serum concentrations were observed in patient subgroups with invasive lobular carcinoma (P<0.0167), higher TNM stage (P<0.001), and positive lymph node metastasis (P<0.001). The estimated mean survival time of patients with YKL-40 positive tumors was significantly shorter than for patients with YKL-40 negative tumors (55.13 months vs 65.78 months, P = 0.017). Multivariable Cox-regression analysis identified a significant association of overall survival time with YKL-40 serum concentration. Patients with YKL-40 positive tumors had significantly shorter disease free survival times than those with YKL-40 negative tumors. We propose that the potential utility of YKL-40 intratumoral staining or serum concentration as a biomarker for breast cancer is greatest within 5 years of diagnosis.

Chronic obstructive pulmonary disease and lung cancer: common pathogenesis, shared clinical challenges

Environmental inhaled noxious particles have been known to play a role in several lung diseases, including chronic obstructive pulmonary disease (COPD) and lung cancer, the deadliest malignancy in the world in both sexes. Of the known noxious agents, tobacco smoking is the leading preventable cause of death worldwide and is a recognized risk for the development of both diseases. The association between COPD and lung cancer has been demonstrated in population-based studies, lung cancer screening programs, epidemiological surveys, and case control and biological mechanistic studies. There is evidence that cumulative smoking history is associated with the risk of developing lung cancer and COPD; however, the majority of smokers do not develop clinical COPD or lung cancer. This suggests the presence of one or several factors that modulate the responses to the offending agents and define the final risk for disease development. The 54th Aspen Lung Conference was convened to provide a forum for a systematic dissection of the potential mechanisms by which persons exposed to the causative agents are able to handle and control the process or, in the case of dysfunctional response, the mechanisms that take off in different directions and result in injury and disease. This summary reviews the themes presented and attempts to integrate them for those clinicians and researchers interested in these topics. The challenges and future directions emanating from the discussions may help frame future conferences and hopefully inspire the interest of young researchers.