Increased expression of chitinase 3-like 1 is a prognosis marker for non-small cell lung cancer correlated with tumor angiogenesis

Different types of tumor microvessels in stage I-IIIA squamous cell lung cancer and their clinical significance

BACKGROUND

Lung cancer (LC) is the leading cause of morbidity and mortality among malignant neoplasms. Improving the diagnosis and treatment of LC remains an urgent task of modern oncology. Previously, we established that in gastric, breast and cervical cancer, tumor microvessels (MVs) differ in morphology and have different prognostic significance. The connection between different types of tumor MVs and the progression of LC is not well understood.

AIM

To evaluate the morphological features and clinical significance of tumor MVs in lung squamous cell carcinoma (LUSC).

METHODS

A single-center retrospective cohort study examined medical records and archival paraffin blocks of 62 and 180 patients with stage I-IIIA LUSC in the training and main cohorts, respectively. All patients underwent radical surgery (R0) at the Orenburg Regional Cancer Clinic from May/20/2009 to December/14/2021. Tumor sections were routinely processed, and routine Mayer's hematoxylin and eosin staining and immunohistochemical staining for cluster of differentiation 34 (CD34), podoplanin, Snail and hypoxia-inducible factor-1 alpha were performed. The morphological features of different types of tumor MVs, tumor parenchyma and stroma were studied according to clinicopathological characteristics and LUSC prognosis. Statistical analysis was performed using Statistica 10.0 software. Univariate and multivariate logistic regression analyses were performed to identify potential risk factors for LUSC metastasis to regional lymph nodes (RLNs) and disease recurrence. Receiver operating characteristic curves were constructed to discriminate between patients with and without metastases in RLNs and those with and without disease recurrence. The effectiveness of the predictive models was assessed by the area under the curve. Survival was analyzed using the Kaplan-Meier method. The log-rank test was used to compare survival curves between patient subgroups. A value of P < 0.05 was considered to indicate statistical significance.

RESULTS

Depending on the morphology, we classified tumor vessels into the following types: normal MVs, dilated capillaries (DCs), atypical DCs, DCs with weak expression of CD34, "contact-type" DCs, structures with partial endothelial linings, capillaries in the tumor solid component and lymphatic vessels in lymphoid and polymorphocellular infiltrates. We also evaluated the presence of loose, fine fibrous connective tissue (LFFCT) and retraction clefts in the tumor stroma, tumor spread into the alveolar air spaces (AASs) and fragmentation of the tumor solid component. According to multivariate analysis, the independent predictors of LUSC metastasis in RLNs were central tumor location (P < 0.00001), the presence of retraction clefts (P = 0.003), capillaries in the tumor solid component (P = 0.023) and fragmentation in the tumor solid component (P = 0.009), whereas the independent predictors of LUSC recurrence were tumor grade 3 (G3) (P = 0.001), stage N2 (P = 0.016), the presence of LFFCT in the tumor stroma (P < 0.00001), fragmentation of the tumor solid component (P = 0.0001), and the absence of tumor spread through the AASs (P = 0.0083).

CONCLUSION

The results obtained confirm the correctness of our previously proposed classification of different types of tumor vessels and may contribute to improving the diagnosis and treatment of LUSC.

Significance of chitinase-3-like protein 1 in the pathogenesis of inflammatory diseases and cancer

Chitinase-3-like protein 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly upregulated by various inflammatory and immunological diseases, including several cancers, Alzheimer's disease, and atherosclerosis. Several studies have shown that CHI3L1 can be considered as a marker of disease diagnosis, prognosis, disease activity, and severity. In addition, the proinflammatory action of CHI3L1 may be mediated via responses to various proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 may contribute to a vast array of inflammatory diseases. However, its pathophysiological and pharmacological roles in the development of inflammatory diseases remain unclear. In this article, we review recent findings regarding the roles of CHI3L1 in the development of inflammatory diseases and suggest therapeutic approaches that target CHI3L1.

Chitotriosidase and Neopterin as Two Novel Potential Biomarkers for Advanced Stage and Survival Prediction in Gastric Cancer—A Pilot Study

Gastric cancer is the fifth type of neoplasia most frequently diagnosed and the fourth cause of death among other cancers. Prevalence is around two times higher for males than females. Chitotriosidase and neopterin are two molecular biomarkers with potential diagnostic and prognostic use in malignant pathology. We conducted a longitudinal prospective cohort study on thirty-nine patients with gastric adenocarcinoma, with a male-to-female ratio of 1.78 and an average age of 64.3 ± 9.97 years. No statistically significant differences in biomarker levels at presentation were observed between curative-intent surgery (28 patients) and advanced cases, suited only for palliative procedures (11 patients). Biomarker values were not significantly different for the advanced T stage and the presence of metastasis (p > 0.05—Mann Whitney test). The patients that died in the first 30 days after surgery did not present significantly different values at baseline, in comparison with those that had longer survival times, though a significant cut-off value was observed for chitotriosidase activity at 310 nmol/mL/h [AUC (area under the curve) = 0.78; 95% CI (0.61–0.92)]. The cut-off values corresponding to death after the first year, tumor invasion, and metastasis were not statistically significant. In the COX multivariate model, neopterin did not validate itself as a prognostic biomarker, however, chitotriosidase activity before surgery was significantly associated with overall survival (HR = 1.0038, p = 0.03). We conclude that chitotriosidase may have the potential to improve the prognostic model for gastric adenocarcinoma.

Prognostic Impact of YKL-40 Immunohistochemical Expression in Patients with Colorectal Cancer

This study aims to examine the clinicopathological and prognostic significance of the YKL-40 immunohistochemical expression of tumor and immune cells through human colorectal cancer (CRC) tissue. We performed immunohistochemistry for YKL-40 and investigated the clinicopathological and prognostic impact of the YKL-40 expression of tumor (T-YKL-40) and immune cells (I-YKL-40) in CRC. We also evaluated the correlation between YKL-40 and PD-L1 expression and the immunoscore. YKL-40 was expressed in 22.6% and 64.2% of T-YKL-40 and I-YKL-40, respectively, out of the 265 CRC tissues. The I-YKL-40 expression significantly correlated with well and moderately differentiated tumors. The PD-L1 expression in immune cells significantly correlated with the I-YKL-40 expression, but not T-YKL-40 expression (p = 0.020 and p = 0.846, respectively). The I-YKL-40 expression significantly correlated with a worse overall survival rate but not recurrence-free survival (p = 0.047 and p = 0.080, respectively). However, there was no significant correlation between the T-YKL-40 expression and survival. In CRCs with a high immunoscore, patients with I-YKL-40 expression demonstrated worse overall and recurrence-free survival than those without I-YKL-40 expression. Our results demonstrated that I-YKL-40 expression significantly correlated with tumor differentiation and PD-L1 expression in immune cells. I-YKL-40 expression can be useful for the prognostic stratification of CRC patients.

Selection and Characterization of YKL-40-Targeting Monoclonal Antibodies from Human Synthetic Fab Phage Display Libraries

YKL-40, also known as chitinase-3-like 1 (CHI3L1), is a glycoprotein that is expressed and secreted by various cell types, including cancers and macrophages. Due to its implications for and upregulation in a variety of diseases, including inflammatory conditions, fibrotic disorders, and tumor growth, YKL-40 has been considered as a significant therapeutic biomarker. Here, we used a phage display to develop novel monoclonal antibodies (mAbs) targeting human YKL-40 (hYKL-40). Human synthetic antibody phage display libraries were panned against a recombinant hYKL-40 protein, yielding seven unique Fabs (Antigen-binding fragment), of which two Fabs (H1 and H2) were non-aggregating and thermally stable (75.5 °C and 76.5 °C, respectively) and had high apparent affinities (K_D = 2.3 nM and 4.0 nM, respectively). Reformatting the Fabs into IgGs (Immunoglobulin Gs) increased their apparent affinities (notably, for H1 and H2, K_D = 0.5 nM and 0.3 nM, respectively), presumably due to the effects of avidity, with little change to their non-aggregation property. The six anti-hYKL-40 IgGs were analyzed using a trans-well migration assay in vitro, revealing that three clones (H1, H2, and H4) were notably effective in reducing cell migration from both A549 and H460 lung cancer cell lines. The three clones were further analyzed in an in vivo animal test that assessed their anti-cancer activities, demonstrating that the tumor area and the number of tumor nodules were significantly reduced in the lung tissues treated with H1 (IgG). Given its high affinity and desirable properties, we expect that the H1 anti-hYKL-40 mAb will be a suitable candidate for developing anti-cancer therapeutics.

Roles of chitinase 3-like 1 in the development of cancer, neurodegenerative diseases, and inflammatory diseases

Chitinase 3-like 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly increased by various inflammatory and immunological conditions, including rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, and several cancers. However, its physiological and pathophysiological roles in the development of cancer and neurodegenerative and inflammatory diseases remain unclear. Several studies have reported that CHI3L1 promotes cancer proliferation, inflammatory cytokine production, and microglial activation, and that multiple receptors, such as advanced glycation end product, syndecan-1/αVβ3, and IL-13Rα2, are involved. In addition, the pro-inflammatory action of CHI3L1 may be mediated via the protein kinase B and phosphoinositide-3 signaling pathways and responses to various pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 could contribute to a vast array of inflammatory diseases. In this article, we review recent findings regarding the roles of CHI3L1 and suggest therapeutic approaches targeting CHI3L1 in the development of cancers, neurodegenerative diseases, and inflammatory diseases.

Defective Sphingolipids Metabolism and Tumor Associated Macrophages as the Possible Links Between Gaucher Disease and Blood Cancer Development

There is a rising number of evidence indicating the increased risk of cancer development in association with congenital metabolic errors. Although these diseases represent disorders of individual genes, they lead to the disruption of metabolic pathways resulting in metabolite accumulation or their deficiency. Gaucher disease (GD) is an autosomal recessive sphingolipidosis. It is a rare lysosomal storage disease. A strong correlation between GD and different types of cancers, such as multiple myeloma, leukemia, and hepatocellular carcinoma, has been reported. Common features for all types of GD include spleen and liver enlargement, cytopenia, and a variety of bone defects. Overall, the molecular bases leading to the association of GD and cancers are not clearly understood. Here, we describe the role of ceramides in GD, discuss the potential implications of immune cells activation and show how the disturbances in their metabolism might promote blood cancer development.

Functional variant of CHI3L1 gene is associated with neck metastasis in oral cancer

OBJECTIVES

Oral cancer is the most common head and neck malignancy, and it is associated with a high recurrence rate and lymph node metastasis potential. YKL-40, also known as chitinase-3-like protein 1 (CHI3L1), is a secreted glycoprotein that serves as a biomarker in several diseases. It also plays a crucial role in regulating many characteristics of cancer, such as cell growth, migration, anti-apoptosis, and angiogenesis. Accumulating evidence supports the link between single-nucleotide polymorphisms (SNPs) and oral cancer, but no report on the association between CHI3L1 polymorphisms and oral cancer is available. Thus, the present study evaluated the contribution of CHI3L1 SNPs to oral cancer susceptibility and clinicopathology.

MATERIALS AND METHODS

This study recruited a total of 2362 subjects, comprising 1190 healthy male controls and 1172 male patients with oral cancer. Allelic discrimination of the CHI3L1 polymorphisms - 1371 G>A (rs6691378), - 247 G>A (rs10399805), - 131 C>G (rs4950928), and + 2950 T>C (rs880633) was assessed through real-time polymerase chain reaction.

RESULTS

We detected a significant association of rs10399805 and rs6691378 with the risk of oral cancer (AOR, 1.537; 95% CI, 1.089-2.168; p = 0.014; AOR, 1.561; 95% CI, 1.131-2.156; p = 0.007, respectively) after adjustment for three potential confounders, smoking, betel nut chewing, and alcohol consumption. Moreover, we found that oral cancer patients carrying the homozygous A/A genotype of the rs10399805 (p = 0.035) or rs6691378 polymorphism (p = 0.023) showed a significantly lower risk of lymph node metastasis. Moreover, according to the Genotype-Tissue Expression database, the rs10399805 and rs6691378 polymorphisms in the promoter region were associated with decreased levels of CHI3L1 mRNA.

CONCLUSIONS

In conclusion, we found that the homozygous mutant allele of rs10399805 and rs6691378 appeared to have significantly lower risk of lymph node metastasis and associated with its mRNA levels in oral cancer.

CLINICAL RELEVANCE

The CHI3L1 polymorphisms rs10399805 and rs6691378 may act as biomarkers for predicting lymph node metastasis in oral cancer patients.

Influence of YKL-40 gene RNA interference on the biological behaviors of endometrial cancer HEC-1A cells

The present study aimed to investigate the effects of chitinase-3-like protein 1 (YKL-40) gene RNA interference on the biological behaviors and enhanced chemosensitivity of endometrial cancer (EC) HEC-1A cells. YKL-40 small interfering (si)RNA was transduced into EC HEC-1A cells using a lentivirus. The experiment was divided into three groups: The experimental group was transfected with YKL-40 siRNA (si-YKL-40); the mock-treatment group was transfected with transfection reagent only; and the blank control group was left untreated. A reverse transcription-quantitative polymerase chain reaction was performed to investigate the mRNA expression levels of YKL-40. The biological behaviors, including cell proliferation, migration, invasion and apoptosis, were detected by MTT and Transwell assays, and flow cytometry (FCM) analysis, respectively. The results of the present study demonstrated that the mRNA expression levels of YKL-40 were downregulated within HEC-1A cells upon transfection with si-YKL-40 (P<0.05). The proliferative, migratory and invasive abilities of HEC-1A cells were inhibited by si-YKL-40 (P<0.05). The mRNA expression levels of YKL-40 were upregulated within HEC-1A cells following treatment with cisplatin (P<0.05). FCM analysis revealed that the average cellular apoptosis rate increased following the inhibition of YKL-40 gene expression via siRNA (P<0.05). Therefore, the YKL-40 gene may be associated with the proliferative, migratory, invasive and anti-apoptotic ability of HEC-1A cells. YKL-40 downregulation may enhance the sensitivity of human EC HEC-1A cells to chemotherapy.

Improving the thermostability of Serratia marcescens B4A chitinase via G191V site-directed mutagenesis

Chitinases with high thermostability are important for many industrial and biotechnological applications. This study was conducted to enhance the stability of Serratia marcescens B4A chitinase by site directed mutagenesis of G191 V. Further characterization showed that the thermal stability of the mutant showed marked increase of about 5 and 15 fold at 50 and 60 °C respectively, while the optimum temperature and pH was retained. Kinetic analysis showed decreased K_m and V_max of the mutant in comparison with the wild type chitinase of about 1.3 and 3 fold, respectively. Based on structural prediction, it was speculated that this replacement shortened an important loop concomitant with the extension of adjacent β sheets. Accordingly, a higher thermostability of G191 V up to 90 °C supporting the decreased flexibility of unfolded state was also indicated. Finally, a practical proof of kinetic and thermal stabilization of chitinase was provided through decreased flexibility and entropic stabilization of its surface loops.

iTRAQ-based quantitative proteomic analysis and bioinformatics study of proteins in retinoblastoma

The aim of the present study was to analyze proteins in the aqueous humor (AH) of patients' retinoblastoma (RB), and investigate their potential role in RB using the comparative proteomic technique of isobaric tags for relative and absolute quantitation (iTRAQ) coupled with offline two-dimensional liquid chromatography-tandem mass spectrometry. A total of 0.1 ml AH was collected from 10 children with RB (mean age, 3.8 years; range, 2-5 years) and patients with senile cataracts (mean age, 70.4 years; range, 65-79 years), which was used as the control. iTRAQ was used to analyze proteins in the AH of patients and controls. Proteins with a fold change of >1.20 or <0.83 were considered to be significantly differentially expressed (with corrected P<0.05). The identified proteins were subjected to subsequent gene ontology (GO) analysis using the DAVID database. A total of 83 proteins that were expressed differently between the controls and patients' AH samples were identified using iTRAQ analysis. Of these proteins, 44 were upregulated and 39 were downregulated. On the basis of biological processes in GO, the identified proteins were primarily involved in glycoprotein, amyloid acute-inflammatory and defensive responses. Among these proteins, pigment epithelium-derived factor serves a potential role in the treatment of RB, and stimulated by retinoic acid 6 may serve as a potential protein involved in RB development. To the best of our knowledge, the present study is the first to identify 83 proteins associated with RB using iTRAQ technology. The results of the present study will aid in furthering the understanding of RB and developing novel therapy targets in the future.

CHI3L1 and CHI3L2 overexpression in motor cortex and spinal cord of sALS patients

BACKGROUND

Amyotrophic Lateral Sclerosis (ALS) is a rapidly progressive neurodegenerative disease characterized by the degeneration and death of upper (UMN) and lower (LMN) motor neurons. In the last decade, it has been shown that Chitinases are an important prognostic indicator of neuro-inflammatory damage induced by microglia and astrocytes.

MATERIALS AND METHODS

We analyzed microarray datasets obtained from the Array Express in order to verify the expression levels of CHI3L1 and CHI3L2 in motor cortex biopsies of sALS patients with different survival times. We also divided the sALS patients into smokers and non-smokers. In order to extend our analysis, we explored two additional microarray datasets, GSE833 and GSE26927, of post-mortem spinal cord biopsies from sALS patients.

RESULTS

The analysis showed that CHI3L1 and CHI3L2 expression levels were significantly upregulated in the motor cortex of sALS patients, compared to the healthy controls. Moreover, their expression levels were negatively correlated with survival time. Interesting results were obtained when we compared the expression levels of Chitinases among smokers. We showed that CHI3L1 and CHI3L2 were significantly upregulated in sALS smokers compared to non-smokers. Furthermore, we found that four genes belonging to the Chitinases network (SERPINA3, C1s, RRAD, HLA-DQA1) were significantly upregulated in the motor cortex of sALS patients and positively correlated with Chitinases expression levels. Similar results were obtained during the exploration of the two-microarray dataset.

CONCLUSIONS

This study suggests that CHI3L1 and CHI3L2 are associated with the progression of neurodegeneration in motor cortex and spinal cord of sALS patients.

CHI3L1 overexpression is associated with metastasis and is an indicator of poor prognosis in papillary thyroid carcinoma

OBJECTIVE

In this study, we examined the relationships between the expression level of CHI3L1 and the clinicopathological characteristics of papillary thyroid carcinoma.

METHODS

A total of 322 tissue samples from patients with papillary thyroid carcinoma were collected, and the CHI3L1 expression levels in tumor tissues, matched adjacent noncancerous tissues were detected using immunohistochemistry (IHC) and qRT-PCR. The relationships between CHI3L1 expression levels and the clinical characteristics were evaluated.

RESULTS

CHI3L1 expression was significantly increased in papillary thyroid carcinoma compared with matched adjacent noncancerous tissues (P< 0.001), tumor tissues with lymph node metastasis (LNM) compared with tumor tissues without LNM (P< 0.001) and tumor tissues with distant organ metastasis (DOM) compared with tumor tissues without DOM (P< 0.01). CHI3L1 expression was significantly associated with tumor size (P= 0.0001), lymph node metastasis (P< 0.0001), distant organ metastasis (P< 0.0001), extrathyroid invasion (P= 0.0022), vascular invasion (P= 0.0004) and TNM stage (P= 0.0001). CHI3L1 overexpression in papillary thyroid carcinoma tissues correlates with the tumor malignant potential (P< 0.01). More importantly, Cox multifactor analysis indicated that patients with high CHI3L1 expression have lower overall survival, disease-free survival, lymph node recurrence-free survival, and distant recurrence free survival rates than those with low expression (P< 0.05). And our findings were further validated by online Oncomine database.

CONCLUSIONS

CHI3L1 is associated with tumor metastasis and might be a prognostic biomarker for papillary thyroid carcinoma.

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.

Immunomodulatory Effects of Chitotriosidase Enzyme

Chitotriosidase enzyme (EC: 3.2.1.14) is the major active chitinase in the human body. It is produced mainly by activated macrophages, in which its expression is regulated by multiple intrinsic and extrinsic signals. Chitotriosidase was confirmed as essential element in the innate immunity against chitin containing organisms such as fungi and protozoa; however, its immunomodulatory effects extend far beyond innate immunity. In the current review, we will try to explore the expanding spectrum of immunological roles played by chitotriosidase enzyme in human health and disease and will discuss its up-to-date clinical value.

Circulating and Tissue Expression Levels of YKL-40 in Renal Cell Cancer

PURPOSE

Blood levels of YKL-40 are elevated in various malignancies and other inflammatory diseases. Higher YKL-40 levels have consequently been shown to correlate with poor prognosis in several cancers. We investigated the prognostic value of circulating and tissue levels of YKL-40 in renal cell cancer.

MATERIALS AND METHODS

Preoperative YKL-40 serum/plasma levels were determined in 222 surgically treated patients with renal cell cancer and in 35 controls. Postoperative serum samples were analyzed in 19 of the 222 renal cell cancer cases. Gene expression levels were assessed in 101 renal cell cancer frozen tissue samples using quantitative real-time reverse transcriptase-polymerase chain reaction. Finally immunohistochemical analysis was done in 37 renal cell cancer cases to assess tissue localization of YKL-40. Results were correlated with clinicopathological and followup data.

RESULTS

YKL-40 serum but not tissue gene expression levels were higher in patients with renal cell cancer compared to controls (p = 0.050). Serum YKL-40 levels significantly increased following nephrectomy (p <0.001). High circulating YKL-40 concentrations were independently associated with shorter survival in the serum and plasma cohorts. YKL-40 gene expression did not correlate with patient prognosis.

CONCLUSIONS

Preoperatively elevated circulating levels of YKL-40 predict survival in patients treated with nephrectomy for renal cell cancer independently of levels determined in serum or plasma. Tumor cells do not seem to be the main source of increased serum/plasma YKL-40 levels in patients with renal cell cancer.

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.

Different pediatric brain tumors are associated with different gene expression profiling

Malignant brain tumors are the most common pediatric solid tumors and are the leading cause of death from childhood cancers. These tumors include several histologic subtypes. Due to the particular properties of brain tumors, such as growth and division, examination of brain tumors and the analysis of results are not simple. Up to date there is a dearth of useful biomarkers that have been validated and clinically implemented for pediatric brain tumors. In order to identify the new genetic alterations we recognized, using microarray dataset, chitinases as new potential biomarkers of CNS tumors. The modulation of chitinases was confirmed also in the different histologic subtypes. Our study revealed that distinct patterns of chitinases expression characterize the diverse histological subtypes. In addition evaluating other lisosomal enzymes such as glycosidases and proteases we found that NEU4, CTBS and GBA2 belonging to glycosidases family and CTSC, CTSK and CTSF belonging to proteases family were differently modulated. Future investigations are needed to be performed before some of these enzymes could finally be used as biomarkers of specific types of CNS neoplasms.