Chitinase 3 like 1 (CHI3L1) promotes vasculogenic mimicry formation in cervical cancer

A humanized Anti-YKL-40 antibody inhibits tumor development

Drugs specifically targeting YKL-40, an over-expressed gene (CHI3L1) in various diseases remain developed. The current study is to create a humanized anti-YKL-40 neutralizing antibody and characterize its potentially therapeutic signature. We utilized in silico CDR-grafting bioinformatics to replace the complementarity determining regions (CDRs) of human IgG1 with mouse CDRs of our previously established anti-YKL-40 antibody (mAY). In fifteen candidates (VL1-3/VH1-5) of heavy and light chain variable region combination, one antibody L3H4 named Rosazumab demonstrated strong binding affinity with YKL-40 (KD = 4.645 × 10-8 M) and high homology with human IgG (80 %). In addition, we established different overlapping amino acid peptides of YKL-40 and found that Rosazumab specifically bound to residues K337, K342, and R344, the KR-rich functional domain of YKL-40. Rosazumab inhibited migration and tube formation of YKL-40-expressing tumor cells and induced tumor cell apoptosis. Mechanistically, Rosazumab induced interaction of N-cadherin with β-catenin and activation of downstream MST1/RASSF1/Histone H2B axis, leading to chromosomal DNA breakage and cell apoptosis. Treatment of xenografted tumor mice with Rosazumab twice a week for 4 weeks inhibited tumor growth and angiogenesis, but induced tumor apoptosis. Rosazumab injected in mice distributed to blood, tumor, and other multiple organs, but did not impact in function or structure of liver and kidney, indicating non-detectable toxicity in vivo. Collectively, the study is the first one to demonstrate that a humanized YKL-40 neutralizing antibody offers a valuable means to block tumor development.

The Modeling Analysis and Effect of CHI3L1 and CD31-Marked Microvessel Density in the Occurrence and Development of Cervical Squamous Cell Carcinoma

Background

Chitinase-3-like protein 1 (CHI3Ll) has been identified as a novel tumor marker in several cancers. The objective of this study was to detect the expression of Chitinase-3-like protein 1 (CHI3L1) and CD31-labeled microvessel density (MVD) in cervical squamous cell carcinoma (CSCC) and to assess its prognostic impact.

Methods

Elivision™ plus immunohistochemical method was used to detect CHI3L1 expression and MVD in different cervical tissues. We analyzed the relationship between CHI3L1 and MVD in CSCC tissues and investigated the relationship between CHI3L1, MVD, and clinicopathological parameters. Univariate and multivariate survival analyses were performed to assess the impact on progression-free survival (PFS) and overall survival (OS).

Results

The positive expression rate of CHI3L1 protein in CSCC tissues (69.9%, 72/103) was significantly higher than that in high-grade cervical intraepithelial lesions (53.3%, 32/60), low-grade cervical intraepithelial lesions (25%, 15/60), and normal cervical tissues (16.7%, 10/60). MVD values ranged from 6 to 64 in CSCC, and no microvascular formation was observed in normal cervical tissues, high-grade intraepithelial lesions, or low-grade intraepithelial lesions. The high expression of CHI3L1 and MVD was significantly correlated with the invasion depth, differentiation degree, vascular invasion, and lymph node metastasis of CSCC (all P < 0.05). In CSCC, the expression of MVD in the CHI3L1 high-expression group (41.35 ± 9.056) was significantly higher than that in the CHI3L1 low-expression group (23.26 ± 11.000, P < 0.05). On univariate Kaplan–Meier analysis, FIGO stage, tumor diameter, lymph node metastasis, vascular invasion, CHI3L1, and MVD of CSCC were related to the prognosis of PFS and OS (all P < 0.05); however, CHI3L1 and MVD were not independent prognostic factors.

Conclusion

CHI3L1 may be involved in the progression of cervical cancer. Its high expression can promote neovascularization in the tumor microenvironment. CHI3L1 is a potential therapeutic target in the context of cervical cancer.

miR-556-3p/Disabled Homolog 2-Interacting Protein (dab2ip) Promotes Cancer Progression by Down-Regulating Bcl-2-Like Protein 11 (BIM) Expression in Colorectal Cancer

Colorectal cancer (CRC) is a major threat affecting human health. Studies have shown that miR-556-3p can regulate dab2ip and promote tumor deterioration, and up-regulation of BIM inhibits CRC cell progression. However, the interaction between miR-556-3p/dab2ip and BIM in CRC is unknown. We examined miR-556-3p expression in CRC tissues and cells by RT-qPCR. The impact of miR-556-3p/dab2ip and BIM on CRC cell behaviors were assessed by western blot, transwell and MTT assay. miR-556-3p was highly expressed in CRC and its overexpression increased CRC cell proliferation and migration as well as up-regulated dab2ip and Ki-67 expression. Besides, miR-556-3p could target the BIM and overexpressed miR-556-3p decreased BIM expression. However, silencing of BIM abrogated the impact of overexpressed miR-556-3p on CRC cell proliferation and migration. In conclusion, miR-556-3p/dab2ip promotes cell growth by down-regulating the expression of BIM, thereby promoting the progression of CRC.

Hallmarks of glycogene expression and glycosylation pathways in squamous and adenocarcinoma cervical cancer

Background

Dysregulation of glycogene expression in cancer can lead to aberrant glycan expression, which can promote tumorigenesis. Cervical cancer (CC) displays an increased expression of glycogenes involved in sialylation and sialylated glycans. Here, we show a comprehensive analysis of glycogene expression in CC to identify glycogene expression signatures and the possible glycosylation pathways altered.

Methods

First, we performed a microarray expression assay to compare glycogene expression changes between normal and cervical cancer tissues. Second, we used 401 glycogenes to analyze glycogene expression in adenocarcinoma and squamous carcinoma from RNA-seq data at the cBioPortal for Cancer Genomics.

Results

The analysis of the microarray expression assay indicated that CC displayed an increase in glycogenes related to GPI-anchored biosynthesis and a decrease in genes associated with chondroitin and dermatan sulfate with respect to normal tissue. Also, the glycogene analysis of CC samples by the RNA-seq showed that the glycogenes involved in the chondroitin and dermatan sulfate pathway were downregulated. Interestingly the adenocarcinoma tumors displayed a unique glycogene expression signature compared to squamous cancer that shows heterogeneous glycogene expression divided into six types. Squamous carcinoma type 5 (SCC-5) showed increased expression of genes implicated in keratan and heparan sulfate synthesis, glycosaminoglycan degradation, ganglio, and globo glycosphingolipid synthesis was related to poorly differentiated tumors and poor survival. Squamous carcinoma type 6 (SCC-6) displayed an increased expression of genes involved in chondroitin/dermatan sulfate synthesis and lacto and neolacto glycosphingolipid synthesis and was associated with nonkeratinizing squamous cancer and good survival. In summary, our study showed that CC tumors are not a uniform entity, and their glycome signatures could be related to different clinicopathological characteristics.

Knockdown of YKL-40 inhibits angiogenesis through regulation of VEGF/VEGFR2 and ERK1/2 signaling in endometrial cancer

Studies have demonstrated that small interfering RNA (siRNA) targeting YKL-40 (siYKL-40) inhibits the proliferation, migration, invasion, and induces antiapoptotic abilities of endometrial cancer (EC) HEC-1A cells. However, its effect on angiogenesis is unclear. The present study aimed to investigate the role of YKL-40 in endometrial cancer and the related molecular mechanisms. YKL-40 was knocked down by transfection with siYKL-40 and the effects on angiogenesis, cell viability, and signaling pathways were investigated. The results showed that siYKL-40 inhibited VEGFA levels and tube formation in endothelial cells. Additionally, inhibition of YKL-40 decreased the expression levels of vascular endothelial growth factor (VEGF), phosphorylated vascular endothelial growth factor receptor 2 (pVEGFR2), and phosphorylated extracellular signal-regulated kinases 1 and 2 (pERK1/2). Furthermore, a nude mice xenograft model of EC showed that siYKL-40 inhibited tumor growth. Inhibition of YKL-40 led to suppression of angiogenesis and reduction of microvessel density through VEGF/VEGFR2 and ERK1/2 signaling in endometrial cancer cells. Taken together, this study demonstrated novel molecular mechanisms for role of YKL-40 in EC.

Cooperation Between Cancer and Fibroblasts in Vascular Mimicry and N2-Type Neutrophil Recruitment via Notch2-Jagged1 Interaction in Lung Cancer

Background

Angiogenesis is required for tumor development and metastasis, which is a major part in a pro-tumor microenvironment. Vascular mimicry (VM) is a process in which cancer cells, rather than endothelia, create an alternative perfusion system to support the tumor progression.

Objectives

To validate the role of VM and to develop a strategy to inhibit angiogenesis in lung cancer.

Methods

In this study, we utilized lung cancer samples to verify the existence of VM and conducted several experimental methods to elucidate the molecular pathways.

Results

H1299 and CL1-0 lung cancer cells were unable to form capillary-like structures. VM formation was induced by cancer-associated fibroblast (CAFs) in both in vitro and in vivo experiments. Notch2–Jagged1 cell–cell contact between cancer cells and CAFs contributes to the formation of VM networks, supported by Notch intracellular domain (NICD) 2 nuclear translocation and N2ICD target gene upregulated in lung cancer cells mixed with CAFs. The polarization of tumor-promoting N2-type neutrophil was increased by VM networks consisting of CAF and cancer cells. The intravasation of cancer cells and N2-type neutrophils were increased because of the loose junctions of VM. Disruption of cancer cell–CAF connections by a γ‐secretase inhibitor enforced the anticancer effect of anti‐vascular endothelial growth factor antibodies in a mouse model.

Conclusion

This study provides the first evidence that CAFs induce lung cancer to create vascular-like networks. These findings suggest a therapeutic opportunity for improving antiangiogenesis therapy in lung cancer.

Downregulation of Interleukin-13 Receptor α2 Inhibits Angiogenic Formation Mediated by Chitinase 3-Like 1 in Late Atherosclerotic Lesions of apoE-/- Mice

Aim: Chitinase 3-like 1 (CHI3L1) has the potential to prompt proliferation and angiogenic formation. Interleukin-13 receptor α2 (IL-13Rα2) was regarded as a receptor of CHI3L1; however, it is unknown whether CHI3L1 adjusts the neovascularization in late atherosclerotic lesions of apoE ^-/- mice via IL-13Rα2. Methods: Silicone collars were placed around one of the common carotid arteries of apoE ^-/- mice fed with a high-fat diet. The mice were further injected with Ad.CHI3L1 alone or Ad.CHI3L1 + Ad.IL-13Rα2 shRNA through the caudal vein. The plaque areas in the whole aorta and aortic root were evaluated by Oil Red O staining and H&E staining. The contents of CD31, CD42b, and collagen in carotid plaques were investigated by immunohistochemistry and Masson trichrome staining. The role of CHI3L1 in migration and tube formation of human umbilical vein endothelial cells (HUVECs) was determined by transwell and Matrigel tests. The effect of CHI3L1 on the expression of AKT and extracellular signal-regulated kinase (ERK) was evaluated with the Western blot. Results: The plaque loads in the aorta were significantly more extensive in apoE ^-/- mice injected with Ad.CHI3L1 than those with Ad.CHI3L1 + Ad.IL-13Rα2 shRNA. CHI3L1 significantly increased the contents of CD31 and CD42b and decreased the element of collagen in late-stage atherosclerotic lesions of the carotid arteries. The effects of CHI3L1 on migration, tube formation, and upregulation of phospho-AKT and phospho-ERK of HUVECs were prohibited by inhibitors of phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase kinase (MEK) as well as IL-13Rα2 shRNA. Conclusion: To some extent, CHI3L1 promotes migration and tube formation of HUVECs and neovascularization in atherosclerotic plaques possibly mediated by IL-13Rα2 through AKT and ERK signal pathways.

Prognostic utility of serum YKL-40 in patients with cervical cancer

Inflammation is one of the hallmarks of cancer and plays a crucial role in the development and progression. The objective of the present study was to investigate if high serum YKL-40 is related to poor prognosis in cervical cancer (CC) patients. A prospective biomarker study of 116 patients with CC (FIGO stage Ia: n = 4; Ib: n = 55; II: n = 26; III: n = 26; IV: n = 5) and 152 patients with cervical intraepithelial neoplasia (CIN). The patients received primary surgery, radiotherapy and chemotherapy according to standard guidelines during the period 2001-2004. Seventy patients died during the follow-up period (median 117 months, range 104-131). Serum concentrations of YKL-40 were measured by ELISA. Serum concentrations of YKL-40 were increased (p < .001) in CC patients (median 76 µg/L, IQR 45-148) compared to CIN patients (44 µg/L, IQR 30-61) and healthy women (41 µg/L, IQR 29-58). YKL-40 was elevated (>age-corrected 95th percentile of YKL-40 in healthy women) in 30 (26%) of the CC patients. Univariate Cox analysis demonstrated that YKL-40 (included as a log-transformed continuous variable (base 2)) was associated with recurrence-free survival (RFS) (HR = 1.48, 95% CI: 1.11-1.98, p = .008) and overall survival (OS) (HR = 1.74, 1.44-2.10, p < .0001). Multivariate Cox analysis showed that stage (II + III vs. I: HR = 2.92, 1.37-6.20, p = .005), YKL-40 (HR = 1.35, 1.06-1.73, p = .018) and age (HR = 1.56, 1.21-1.99, p = .0005) were independent prognostic variables of OS. During treatment, a 2-fold increase in YKL-40 compared to baseline level was associated with short RFS (HR = 1.87, 1.27-2.77, p = .0016) and OS (HR = 1.78, 1.26-2.50, p = .0010). Serum YKL-40 is an independent biomarker of OS in patients with cervical cancer.

Chitinase-3 like-protein-1 function and its role in diseases

Non-enzymatic chitinase-3 like-protein-1 (CHI3L1) belongs to glycoside hydrolase family 18. It binds to chitin, heparin, and hyaluronic acid, and is regulated by extracellular matrix changes, cytokines, growth factors, drugs, and stress. CHI3L1 is synthesized and secreted by a multitude of cells including macrophages, neutrophils, synoviocytes, chondrocytes, fibroblast-like cells, smooth muscle cells, and tumor cells. It plays a major role in tissue injury, inflammation, tissue repair, and remodeling responses. CHI3L1 has been strongly associated with diseases including asthma, arthritis, sepsis, diabetes, liver fibrosis, and coronary artery disease. Moreover, following its initial identification in the culture supernatant of the MG63 osteosarcoma cell line, CHI3L1 has been shown to be overexpressed in a wealth of both human cancers and animal tumor models. To date, interleukin-13 receptor subunit alpha-2, transmembrane protein 219, galectin-3, chemo-attractant receptor-homologous 2, and CD44 have been identified as CHI3L1 receptors. CHI3L1 signaling plays a critical role in cancer cell growth, proliferation, invasion, metastasis, angiogenesis, activation of tumor-associated macrophages, and Th2 polarization of CD4⁺ T cells. Interestingly, CHI3L1-based targeted therapy has been increasingly applied to the treatment of tumors including glioma and colon cancer as well as rheumatoid arthritis. This review summarizes the potential roles and mechanisms of CHI3L1 in oncogenesis and disease pathogenesis, then posits investigational strategies for targeted therapies.

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.

Overexpression of chitinase-3-like protein 1 is associated with structural recurrence in patients with differentiated thyroid cancer

We previously identified that the expression of chitinase-3-like protein 1 (CHI3L1) was upregulated during thyroid cancer progression. Here, we investigated the prognostic significance of CHI3L1 expression in thyroid neoplasms and examined the potential oncogenic roles. CHI3L1 immunochemical staining was performed on tissue microarrays of benign and malignant thyroid tumours. Compared with normal thyroid tissue and benign thyroid lesions that had low or no detectable CHI3L1 expression, CHI3L1 was overexpressed in both differentiated and undifferentiated thyroid cancer. High CHI3L1 expression was associated with extrathyroidal extension, lymph node metastasis, and shorter recurrence-free survival in differentiated thyroid cancer. The biological roles of CHI3L1 were further investigated by gain- and loss-of-function assays. CHI3L1 silencing suppressed clonogenicity, migration, invasion, anoikis resistance, and angiogenesis in thyroid cancer cells, although exogenous CHI3L1 treatment promoted these malignant phenotypes. Cysteine-rich angiogenic inducer 61 (CYR61) was identified as a downstream target of CHI3L1 by RNA-seq analysis. CYR61 silencing or treatment reversed the alterations induced by CHI3L1 modulation. Our results demonstrate that CHI3L1 is overexpressed in thyroid cancer and is associated with an increased risk of disease recurrence. Additionally, CYR61 may participate in CHI3L1-mediated tumour progression. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Integrating SWATH-MS Proteomics and Transcriptome Analysis Identifies CHI3L1 as a Plasma Biomarker for Early Gastric Cancer

Early diagnosis of gastric cancer (GC) provides patients opportunities for minimally invasive endoscopic resection. Here, we developed a new strategy integrated the state-of-the-art sequential windowed acquisition of all theoretical fragment ion (SWATH) mass spectra (MS) with multi-dataset joint analysis to screen for the stage-I GC plasma biomarker. In SWATH-MS assays, we identified 37 upregulated and 21 downregulated proteins in GC plasma. In the mRNA database analysis, 633 genes were identified as differentially expressed genes in at least 4 out of 5 datasets, but there were only 94 genes identified as upregulated. Only 1 gene, CHI3L1, was characterized as upregulated in both the dataset consensus list and the SWATH-MS list. Then, we detected the CHI3L1 level in the plasma of a large cohort consisting of 200 participants. The area under the ROC curve (AUC) of CHI3L1 in distinguishing GC from others was 0.788. Integrating the plasma CHI3L1 level with clinical factors further boosted the AUC to 0.887. In conclusion, we provide a novel strategy for biomarker screening, combining recent MS techniques with public database analysis, and identified plasma CHI3L1 as a potential biomarker for patients with endoscopically resectable GC.

Chitinase 3 like 1 suppresses the stability and activity of p53 to promote lung tumorigenesis

Background

Chitinase 3 like 1 protein (Chi3L1) is expressed in several cancers, and a few evidences suggest that the secreted Chi3L1 contributes to tumor development. However, the molecular mechanisms of intracellular Chi3L1 are unknown in the lung tumor development. Methods: In the present study, we generated Chi3L1 knockout mice (Chi3L1^KO(−/−)) using CRISPR/Cas9 system to investigate the role of Chi3L1 on lung tumorigenesis.

Results

We established lung metastasis induced by i.v. injections of B16F10 in Chi3L1^KO(−/−). The lung tumor nodules were significantly reduced in Chi3L1^KO(−/−) and protein levels of p53, p21, BAX, and cleaved-caspase 3 were significantly increased in Chi3L1^KO(−/−), while protein levels of cyclin E1, CDK2, and phsphorylation of STAT3 were decreased in Chi3L1^KO(−/−). Allograft mice inoculated with B16F10 also suppressed tumor growth and increased p53 and its target proteins including p21 and BAX. In addition, knockdown of Chi3L1 in lung cancer cells inhibited lung cancer cell growth and upregulated p53 expression with p21 and BAX, and a decrease in phosphorylation of STAT3. Furthermore, we found that intracellular Chi3L1 physically interacted and colocalized with p53 to inhibit its protein stability and transcriptional activity for target genes related with cell cycle arrest and apoptosis. In lung tumor patient, we clinically found that Chi3L1 expression was upregulated with a decrease in p53 expression, as well as we validated that intracellular Chi3L1 was colocalized, reversely expressed, and physically interacted with p53, which results in suppression of the expression and function of p53 in lung tumor patient.

Conclusions

Our studies suggest that intracellular Chi3L1 plays a critical role in the lung tumorigenesis by regulating its novel target protein, p53 in both an in vitro and in vivo system.

G721-0282 inhibits cell growth and induces apoptosis in human osteosarcoma through down-regulation of the STAT3 pathway

Osteosarcoma (OS) is considered the most common type of primary malignant bone tumor, which has an urgent need for more effective treatment. Recently, chitinase 3 like 1 (Chi3L1) expression has been found in a variety of cancer cells. However it is not known whether Chi3L1 regulates the STAT3 pathway in OS cells. Herein, we examined the effects of the G721-0282, a ligand of Chi3L1, in vitro and in vivo against OS cells. G721-0282 inhibited the proliferation of OS cells and induced apoptosis. This apoptosis was accompanied by upregulation of apoptotic proteins (PARP and procaspase-3), but downregulation of anti-apoptotic proteins (Survivin and Bcl-2). G721-0282 induced the inactivation of mitogen-activated protein kinases (MAPKs) with a decrease in the phosphorylation of Src and STAT3 in OS cells. Importantly, overexpression of Chi3L1 potentiated the effects of G721-0282, while knockdown of Chi3L1 attenuated the effects of G721-0282. Docking model study also showed that G721-0282 interacted with Chi3L1. In addition, G721-0282 inhibited cell migration, invasion, and colony formation. Furthermore, the anti-tumor effects of G721-0282 were observed in an xenograft in vivo model in association with the reduced expression of Chi3L1, PCNA, Cyclin D1, p-STAT3, as well as the increased expression of Chi3L1 was correlated with the p-STAT3 level in human bone tumor tissues. Taken together, a Chi3L1 ligand, G721-0282 may be an attractive therapeutic strategy for OS, especially in vitro and in vivo anti-proliferative effects against OS cells through the inhibition of the STAT3 pathway, and suggest the potentially therapeutic application of G721-0282 in the treatment of OS.

Upregulation Of circMMP9 Promotes Osteosarcoma Progression Via Targeting miR-1265/CHI3L1 Axis

Background

Osteosarcoma (OS) is a very aggressive cancer. Nevertheless, how circular RNA (circRNA) contributes to OS progression remains unclear. Here, we aimed to research the functions of circMMP9 in OS progression.

Methods

Gene expression was determined via qRT-PCR. siRNA was used to knock down circMMP9. Proliferation was analyzed using CCK8 and colony formation assays. Migration and invasion were measured using Transwell assay.

Results

circMMP9 was overexpressed in cancer tissues. Overexpressed circMMP9 was correlated with advanced tumor stage and predicted poor prognosis. circMMP9 knockdown exhibited a tumor-suppressive phenotype via suppressing proliferation, migration and invasion. Besides, decreased circMMP9 level promoted OS cellular apoptosis. Mechanistically, circMMP9 was shown to be located in the cytoplasm and sponge miR-1265. Furthermore, miR-1265 directly targeted CHI3L1. CHI3L1 levels were modulated by circMMP9/miR-1265 axis. Rescue experiments indicated that circMMP9 contributes to OS development through the miR-1265/CHI3L1 pathway.

Conclusion

Our findings provide a novel insight about how circRNA regulates OS progression.

CHI3L1 promotes proliferation and improves sensitivity to cetuximab in colon cancer cells by down-regulating p53

Background

Chitinase 3‐like protein 1 (CHI3L1) is most likely a malignant tumor metastasis‐associated gene. However, the functions of CHI3L1 in colon cancer cell proliferation and its cetuximab sensitivity are still unclear. We aimed to investigate the mechanism of CHI3L1 in promoting colon cancer cell proliferation and its sensitivity to cetuximab.

Methods

The expression of CHI3L1 in colon cancer and adjacent tissues were detected by immunohistochemistry. CHI3L1 was overexpressed in colon cancer cell lines by lentiviral technology. Cell proliferation and sensitivity to cetuximab were measured by MTT assay, cell cycle was analyzed by flow cytometry, and expression of cell cycle‐related proteins was analyzed by immunoblotting.

Results

The results showed that the level of CHI3L1 in colon cancer tissue was significantly higher than that in adjacent tissue, which was also correlated with overall survival. The cell proliferation rate was significantly increased after overexpression of CHI3L1, and the sensitivity to cetuximab was significantly increased. The expression of p53 was down‐regulated while the EGFR was up‐regulated significantly in CHI3L1 overexpressed cells. When rescued the expression of p53 in HCT116‐CHI3L1 cells, the cell proliferation and sensitivity to cetuximab could be restored.

Conclusion

High levels of CHI3L1 are associated with poor prognosis and accelerate the proliferation of colon cancer cells and increase the sensitivity to cetuximab. Its mechanism of increasing the cell proliferation and sensitivity to cetuximab may be explained by down‐regulating p53 expression and then, up‐regulating the expression of EGFR.

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.