Chondroitin polymerizing factor (CHPF) promotes development of malignant melanoma through regulation of CDK1

Sodium Propionate Alleviates Atopic Dermatitis by Inhibiting Ferroptosis via Activation of LTBP2/FABP4 Signaling Pathway

Background

Atopic dermatitis (AD) is a common pediatric skin disease, with recent studies suggesting a role for ferroptosis in its pathogenesis. Sodium propionate (SP) has shown therapeutic potential in AD, yet its mechanism, particularly regarding ferroptosis modulation, remains unclear. This study aims to explore whether SP alleviates AD by modulating ferroptosis-related pathways through bioinformatic and in vitro analyses.

Methods

We analyzed the GEO AD cohort (GSE107361). Ferroptosis-related genes was compiled from the GeneCards Database and SP-associated therapeutic target genes were obtained from Swiss Target Prediction. To explore potential biological mechanisms, we employed Gene Set Variation Analysis (GSVA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Weighted Gene Co-expression Network Analysis (WGCNA) and differential expression analysis identified key gene modules. We also established TNF-α/IFN-γ induced AD cell models using HaCat cells and collected cell samples for further experiments.

Results

The GSVA analysis demonstrated that ferroptosis-related genes could differentiate between healthy children and those with AD. The identified module includes genes with correlated expression patterns specifically linked to AD. Analysis using three algorithms identified potential therapeutic targets of SP. We screened 51 key genes related to AD and ferroptosis, selecting cyclin-dependent kinase 1 (CDK1) and latent transforming growth factor beta binding protein 2 (LTBP2) as co-expressed genes. Machine learning identified fatty acid binding protein 4 (FABP4) as a significant gene intersection of the 51 key genes. The bioinformatics analysis results were validated through cell experiments, showing that SP treatment increased the expression of the damaged skin genes loricrin (LOR) and filaggrin (FLG).

Conclusion

Our study indicates that SP may alleviate AD symptoms by modulating ferroptosis through the LTBP2/FABP4 pathway.

Analysis of the role of CHPF in colorectal cancer tumorigenesis and immunotherapy based on bioinformatics and experiments

BACKGROUND

Chondroitin polymerizing factor (CHPF) has been found to be involved in the development of numerous cancers and correlated with poor prognosis. However, its role in the tumorigenesis and development of colorectal cancer (CRC) remains unknown.

METHODS

In our research, we explored CHPF expression and clinicopathological characteristics using The Cancer Genome Atlas Program (TCGA), UALCAN, GSE9348, TIMER2.0 and The Human Protein Atlas (HPA) database, in addition, we validated CHPF expression in CRC cell lines by Real-Time Quantitative PCR (qRT-PCR) and Western blot (WB). KM-Plotter, PrognoScan and TCGA were also utilized to verify its prognosis value in CRC. Small-interfer RNA (Si-RNA) was used to perform Cell Counting Kit-8 (CCK8), colony formation, 5-ethynyl-2'-deoxyuridine (EDU), transwell and wound healing assays to testify its function on the tumor progression. Based on TCGA database, we probed potential biological mechanism by which CHPF play its role via clusterProfiler package and GEPIA database and we validated their correlation by WB assay. Moreover, we explored its potential association with the tumor microenvironment (TME), immune infiltrated cells, immune checkpoints, tumor mutation burden (TMB) as well as microsatellite instability (MSI), and investigated immunotherapy sensitivity via Tumor Immune Dysfunction and Exclusion (TIDE) algorithm as well as potentially effective therapeutic drugs via pRRophetic algorithm.

RESULTS

CHPF was identified upregulated in CRC tissues and cells, correlated with poor prognosis, and nodal metastasis status, stage and histological subtype. Down-regulation of CHPF inhibited CRC cell proliferation, migration and its expression correlated with wnt pathway key molecules. In addition, high expression of CHPF was positively correlated with TME scores, Regulatory T cells (Tregs) cell infiltration degree, Programmed death-1 (PD-1), MSI-high (MSI-H), and TIDE scores, however, not with TMB. Targeted drug analysis showed that patients with high CHPF expression were more sensitive to telatinib, recaparib, serdemetan, and trametinib.

CONCLUSION

CHPF could promote the proliferation and migration of CRC cells and lead to poor prognosis, possibly through wnt pathways as well as changes in TME. Patients with high expression of CHPF had poor efficacy in immunotherapy, which might be related to Tregs cell infiltration. Above all, it might offer more reliable guidance for future immunotherapy.

MEK-mediated CHPF2 phosphorylation promotes colorectal cancer cell proliferation and metastasis by activating NF-κB signaling

The cytokine tumor necrosis factor (TNF) plays a crucial role in the proliferation and metastasis of colorectal cancer (CRC) cells, but the underlying mechanisms remain poorly understood. Here, we report that chondroitin polymerizing factor 2 (CHPF2) promotes CRC cell proliferation and metastasis mediated by TNF, independently of its enzymatic activity. CHPF2 is highly expressed in CRC, and its elevated expression is associated with poor prognosis of CRC patients. Mechanistically, upon TNF stimulation, CHPF2 is phosphorylated at the T588 residue by MEK, enabling CHPF2 to interact with both TAK1 and IKKα. This interaction enhances the binding of TAK1 and IKKα, leading to increased phosphorylation of the IKK complex and activation of NF-κB signaling. As a result, the expression of early growth factors (EGR1) is upregulated to promote CRC cell proliferation and metastasis. In contrast, introduction of a phospho-deficient T588A mutation in CHPF2 weakened the interaction between CHPF2 and TAK1, thus impairing NF-κB signaling. CHPF2 T588A mutation reduced the ability of CHPF2 to promote the proliferation and metastasis of CRC in vitro and in vivo. Furthermore, the NF-κB RELA subunit promotes CHPF2 expression, further amplifying TNF-induced NF-κB signaling activation. These findings identify a moonlighting function of CHPF2 in promoting tumor cell proliferation and metastasis and provide insights into the mechanism by which CHPF2 amplifies TNF-mediated NF-κB signaling activation. Our study provides a molecular basic for the development of therapeutic strategies for CRC treatment.

Liver transcriptome profiles of dairy cows with different serum metabotypes

In a previously established animal model, 38 multiparous Holstein cows were assigned to 2 groups fed different diets to achieve either a normal (NBCS) or high (HBCS) body condition score (BCS) and backfat thickness (BFT) until dry-off at -49 d before calving (NBCS: BCS <3.5 [3.02 ± 0.24) and BFT <1.2 cm [0.92 ± 0.21]; HBCS: BCS >3.75 [3.82 ± 0.33] and BFT >1.4 cm [2.36 ± 0.35], mean ± SD). The groups were also stratified for comparable milk yields (NBCS: 10,361 ± 302 kg; HBCS: 10,315 ± 437 kg; mean ± SD). The cows were then fed the same diet during the dry period and subsequent lactation, maintaining the differences in BFT and BCS throughout the study. Using the serum metabolomics data, we created a classification model that identified different metabotypes. Machine learning classifiers revealed a distinct cluster labeled HBCS-PN (HBCS predicted normal BCS) among over-conditioned cows. These cows showed higher feed intake and better energy balance than the HBCS-PH (high BCS predicted high BCS) group, while milk yield was similar. The aim of this study was to investigate the changes in the hepatic transcriptome of cows differing in serum-metabotype postpartum. We performed hepatic transcriptome analysis in cows from 3 metabolic clusters: HBCS-PH (n = 8), HBCS-PN (n = 6), and normal BCS predicted normal BCS (NBCS-PN, n = 8) on d 21 (±2) postpartum. Liver tissue from cows expressed a total of 13,118 genes aligned with the bovine genome. A total of 48 differentially expressed genes (DEG; false discovery rate ≤0.1 and fold-change >1.5) were found between NBCS-PN and HBCS-PH cows, whereas 24 DEG (14 downregulated and 10 upregulated) were found between HBCS-PN and HBCS-PH cows. The downregulated DEG (n = 31) in NBCS-PN cows compared with HBCS-PH cows are involved in biosynthetic processes such as lipid, lipoprotein, and cholesterol synthesis (e.g., APOA1, MKX, RPL3L, CANT1, CHPF, FUT1, ZNF696), cell organization, biogenesis, and localization (e.g., SLC12A8, APOA1, BRME1, RPL3L, STAG3, FBXW5, TMEM120A, SLC16A5, FGF21), catabolic processes (e.g., BREH1, MIOX, APOBEC2, FBXW5, NUDT16), and response to external stimuli (e.g., APOA1, FGF21, TMEM120A, FNDC4), whereas upregulated DEG (n = 17) are related to signal transduction and cell motility (e.g., RASSF2, ASPN, SGK1, KIF7, ZEB2, MAOA, ACKR4, TCAF1), suggesting altered metabolic adaptations during lactation. Our results showed 24 DEG between HBCS-PN and HBCS-PH in the liver. The expression of SLC12A8, SLC16A5, FBXW5, OSGIN1, LAMA3, KDELR3, OR4X17, and INHBE, which are responsible for regulating cellular processes was downregulated in HBCS-PN cows compared with HBCS-PH cows. In particular, the downregulation of SLC12A8 and SLC16A5 expression in HBCS-PN cows indicates lower metabolic load and reduced need for NAD+ biosynthesis to support mitochondrial respiratory processes. The upregulation of MAOA, ACKR4, KIF27, SFRP1, and CAV2 in the liver of HBCS-PN cows may indicate adaptive mechanisms to maintain normal liver function in response to increased metabolic demands from over-conditioning. These molecular differences underscore the existence of distinct metabolic types in cows and provide evidence for the role of the liver in shaping different metabolic patterns.

MiR-214-3p overexpression-triggered chondroitin polymerizing factor (CHPF) inhibition modulates the ferroptosis and metabolism in colon cancer

Colon cancer is a common cancer with high mortality globally. The role of chondroitin polymerizing factor (CHPF) has been elucidated in various cancers. However, its role and mechanism remain unknown in colon cancer. CHPF expression was examined by GEPIA database, reverse transcription-quantitative polymerase chain reaction and western blot. The relationship between CHPF expression and the clinicopathologic characteristics as well as miR-214-3p level was determined in colon cancer patients. The role and mechanism of CHPF in the growth, ferroptosis, and glycolysis of colon cancer cells were evaluated by cell counting kit-8, biochemical detections, luciferase, and western blot experiments. Additionally, the role of CHPF was explored in xenografted mice. CHPF expression was increased and was related to advanced TNM stage, poor differentiation and shorter overall survival in patients with colon cancer. Knockdown of CHPF inhibited colon cancer cell growth, and downregulated the expression of proteins involving in ferroptosis and glycolysis both in vitro and in vivo. Besides, CHPF silencing increased the levels of ferrous iron and ROS, but decreased glucose uptake, lactate product, and ATP level in vitro. Mechanically, miR-214-3p directly targeted CHPF and negatively regulated its expression. Upregulation of miR-214-3p reduced cell viability, glucose uptake, lactate product, and ATP level, but increased the levels of ferrous iron and ROS, which were reversed by the overexpression of CHPF. Upregulation of CHPF predicted poor prognosis, and miR-214-3p/CHPF axis inhibited growth, downregulated the levels of glycolysis-related indexes, and promoted ferroptosis in colon cancer cells.

Activation of CHPF by transcription factor NFIC promotes NLRP3 activation during the progression of colorectal cancer

Given the role of chondroitin polymerizing factor (CHPF) in several cancers, we investigated its role in the progression of colorectal cancer (CRC) and its association with NLRP3 inflammasome activation. High expression of CHPF in CRC predicted poor patient prognosis. Using colony formation, EdU staining, wound healing, Transwell invasion, and flow cytometry assays, we revealed that the downregulation of CHPF inhibited the malignant behavior of CRC cells. CHPF promoted NLRP3 inflammasome activation by inducing the MAPK signaling pathway, as evidenced by enhanced expression of Phos-ERK1/2, Phos-MEK1, Phos-MEK2, and NLRP3. Additionally, nuclear factor 1 C-type (NFIC) was revealed as a potential upstream transcription factor of CHPF in the modulation of CRC, and the anti-tumor effects elicited through its knockdown were compromised by CHPF in vitro and in vivo. In summary, we demonstrated that NFIC promoted NLRP3 activation to support CRC development via the CHPF-mediated MAPK signaling.

The HNF4A-CHPF pathway promotes proliferation and invasion through interactions with MAD1L1 in glioma

Chondroitin polymerizing factor (CHPF) is an important glycosyltransferases that participates in the biosynthesis of chondroitin sulfate (CS). Our previous study showed that silencing CHPF expression inhibited glioma cell proliferation in vitro, but the molecular mechanisms by which CHPF contributes to development of glioma have not been characterized. In this study, we found that CHPF was up-regulated in glioma tissues and was positively correlated with malignant clinical pathological characteristics of patients with glioma. Silencing CHPF expression inhibited proliferation, colony formation, migration, and cell cycle of glioma cells. Moreover, silencing CHPF suppressed glioma malignance in vivo. Immunoprecipitation, co-immunoprecipitation, GST pulldown, and liquid chromatography-mass spectrometry (LC-MS/MS) assays were used to verify the interaction between CHPF and Mitotic arrest deficient 1-like 1 (MAD1L1). In addition, Chromatin Immunoprecipitation (ChIP)-PCR analysis showed that HNF4A bound to the CHPF promoter region, which indicated that the transcription factor hepatocyte nuclear factor 4A (HNF4A) could regulate the expression of CHPF in glioma cells.

Identification of an optimized glycolytic-related risk signature for predicting the prognosis in breast cancer using integrated bioinformatic analysis

Aberrant metabolic disorders and significant glycolytic alterations in tumor tissues and cells are hallmarks of breast cancer (BC) progression. This study aims to elucidate the key biomarkers and pathways mediating abnormal glycolysis in breast cancer using bioinformatics analysis. Differential genes expression analysis, gene ontology analysis, Kyoto encyclopedia of genes and genomes analysis, gene set enrichment analyses, and correlation analysis were performed to explore the expression and prognostic implications of glycolysis-related genes. We effectively integrated 4 genes to construct a prognostic model of shorter survival in the high-risk versus low-risk group. The prognostic model showed promising predictive value and may be an integral part of the prognosis of BC. The survival analysis and receiver operating characteristic curves suggested that the signature showed a good predictive performance in both the The Cancer Genome Atlas training set and 2 gene expression omnibus validation sets. Multivariable analysis demonstrated that the 4-gene signature had an independent prognostic value. Furthermore, all calibration curves exhibited robust validity in prognostic prediction. We established an optimized 4-gene signature to clarify the connection between glycolysis and BC, and offered an attractive platform for risk stratification and prognosis predication of BC patients.

Targeting CDK1 in cancer: mechanisms and implications

Cyclin dependent kinases (CDKs) are serine/threonine kinases that are proposed as promising candidate targets for cancer treatment. These proteins complexed with cyclins play a critical role in cell cycle progression. Most CDKs demonstrate substantially higher expression in cancer tissues compared with normal tissues and, according to the TCGA database, correlate with survival rate in multiple cancer types. Deregulation of CDK1 has been shown to be closely associated with tumorigenesis. CDK1 activation plays a critical role in a wide range of cancer types; and CDK1 phosphorylation of its many substrates greatly influences their function in tumorigenesis. Enrichment of CDK1 interacting proteins with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was conducted to demonstrate that the associated proteins participate in multiple oncogenic pathways. This abundance of evidence clearly supports CDK1 as a promising target for cancer therapy. A number of small molecules targeting CDK1 or multiple CDKs have been developed and evaluated in preclinical studies. Notably, some of these small molecules have also been subjected to human clinical trials. This review evaluates the mechanisms and implications of targeting CDK1 in tumorigenesis and cancer therapy.

Extracellular vesicles derived from hypoxic HTR-8/SVneo trophoblast inhibit endothelial cell functions through the miR-150-3p /CHPF pathway

INTRODUCTION

Endothelial dysfunction is one of the basic pathological changes in pre-eclampsia. Extracellular vesicles (EVs) can transport miRNAs expressed by placental trophoblast cells into endothelial cells. The aim of this study was to explore the differential effects of EVs induced by hypoxic trophoblasts (1%HTR-8-EV) and those derived from normoxic trophoblasts (20%HTR-8-EV) on the regulation of endothelial cell functions.

METHODS

Normoxia and hypoxia were preconditioned to induce trophoblast cells-derived EVs. The effect of EVs, miRNA, target gene, and their interactions on endothelial cell proliferation, migration, and angiogenesis were determined. Quantitative analysis of miR-150-3p and CHPF were verified by qRT-PCR and western blotting. The binding relationship among EVs pathway was demonstrated by luciferase reporter assay.

RESULTS

Compared with 20%HTR-8-EV, 1%HTR-8-EV had a suppressive effect on proliferation, migration, and angiogenesis of endothelial cells. The results of miRNA sequencing showed the vital role of miR-150-3p in trophoblast-to-endothelium communication. 1%HTR-8-EV carrying miR-150-3p could move into endothelial cells and target chondroitin polymerizing factor (CHPF) gene. MiR-150-3p inhibited endothelial cell functions by regulating CHPF. In patient-derived placental vascular tissues, there was a similar negative correlating between miR-150-3p and CHPF.

DISCUSSION

Our findings indicate that extracellular vesicles miR-150-3p derived from hypoxic trophoblasts inhibits endothelial cells proliferation, migration, and angiogenesis by modulating CHPF, illuminating a novel mechanism of hypoxic trophoblasts regulation of endothelial cells and their potential role in PE pathogenesis.

IKZF4 acts as a novel tumor suppressor in non-small cell lung cancer by suppressing Notch signaling pathway

Non-small cell lung cancer (NSCLC) is the predominant cause of cancer-related mortality globally, although many clinical efforts have been developed to improve the outcomes. The Ikaros zing-finger family transcription factors (IKZFs) have been proved to play pivotal roles in lymphopoiesis and myeloma progression, but their roles in solid tumors development remain unclear. We performed integrative bioinformatical analysis to determine the dysregulation expression of IKZFs in multiple tumors and the correlation between IKZF4 and NSCLC tumor environment. We showed that IKZFs were dysregulated in multiple tumors and IKZF4 was significantly decreased in NSCLC tissues and cell lines due to promoter hypermethylation. We found that low IKZF4 expression obviously correlated with patients' poor clinical outcome. We revealed that IKZF4 overexpression inhibited NSCLC cell growth, migration and xenograft tumor growth, supporting the inhibitory role of IKZF4 in NSCLC tumorigenesis. Additionally, integrative bioinformatical analysis showed that IKZF4 was involved in NSCLC tumor microenvironment. Mechanically, RNA-seq results showed that IKZF4 forced-expression remarkably suppressed Notch signaling pathway in NSCLC, which was validated by qRT-PCR and immunoblot assays. Moreover, we screened several potential agonists for IKZF4.

Chondroitin polymerizing factor predicts a poor prognosis and promotes breast cancer progression via the upstream TGF-β1/SMAD3 and JNK axis activation

Aberrant composition of glycans in the tumor microenvironment (TME) contributes to tumor progression and metastasis. Chondroitin polymerizing factor (CHPF) is a glycosyltransferase that catalyzes the biosynthesis of chondroitin sulfate (CS). It is also correlated to transforming growth factor-β1 (TGF-β1) expression, a crucial mediator in the interaction of cancer cells with TME. In this study, we investigated the association of CHPF expression with the clinicopathological features of breast cancer (BRCA), as well the oncogenic effect and the underling mechanisms of CHPF upon BRCA cells. We found that CHPF expression is significantly increased in human BRCA tissues, and it is positively associated with TGF-β expression (r = 0.7125). The high-expression of CHPF predicts a poor prognosis and is positively correlated with tumor mass, lymph node metastasis, clinical staging and HER-2 negative-expression. The mechanistic study revealed that it promotes BRCA cell proliferation, migration and invasion through TGF-β1-induced SMAD3 and JNK activation in vitro, JNK (SP600125) or SMAD3 (SIS3) inhibitor can remove the promotion of CHPF upon cell proliferation, migration and invasion in MDA-MB-231 cells, which is derived from triple-negative breast cancer (TNBC). Collectively, our finding suggested CHPF may function as an oncogene and is highly expressed in human BRCA tissues. Pharmacological blockade of the upstream of JNK or SMAD3 signaling may provide a novel therapeutic target for refractory TNBC patients with CHPF abnormal high-expression.

A review on the role of cyclin dependent kinases in cancers

The Cyclin-dependent kinase (CDK) class of serine/threonine kinases has crucial roles in the regulation of cell cycle transition and is mainly involved in the pathogenesis of cancers. The expression of CDKs is controlled by a complex regulatory network comprised of genetic and epigenetic mechanisms, which are dysregulated during the progression of cancer. The abnormal activation of CDKs results in uncontrolled cancer cell proliferation and the induction of cancer stem cell characteristics. The levels of CDKs can be utilized to predict the prognosis and treatment response of cancer patients, and further understanding of the function and underlying mechanisms of CDKs in human tumors would pave the way for future cancer therapies that effectively target CDKs. Defects in the regulation of cell cycle and mutations in the genes coding cell-cycle regulatory proteins lead to unrestrained proliferation of cells leading to formation of tumors. A number of treatment modalities have been designed to combat dysregulation of cell cycle through affecting expression or activity of CDKs. However, effective application of these methods in the clinical settings requires recognition of the role of CDKs in the progression of each type of cancer, their partners, their interactions with signaling pathways and the effects of suppression of these kinases on malignant features. Thus, we designed this literature search to summarize these findings at cellular level, as well as in vivo and clinical levels.

Bioinformatics and Experimental Analysis of the Prognostic and Predictive Value of the CHPF Gene on Breast Cancer

Background

Recent studies in the United States have shown that breast cancer accounts for 30% of all new cancer diagnoses in women and has become the leading cause of cancer deaths in women worldwide. Chondroitin Polymerizing Factor (CHPF), is an enzyme involved in chondroitin sulfate (CS) elongation and a novel key molecule in the poor prognosis of many cancers. However, its role in the development and progression of breast cancer remains unclear.

Methods

The transcript expression of CHPF in the Cancer Genome Atlas-Breast Cancer (TCGA-BRCA), Gene Expression Omnibus (GEO) database was analyzed separately using the limma package of R software, and the relationship between CHPF transcriptional expression and CHPF DNA methylation was investigated in TCGA-BRCA. Kaplan-Meier curves were plotted using the Survival package to further assess the prognostic impact of CHPF DNA methylation/expression. The association between CHPF transcript expression/DNA methylation and cancer immune infiltration and immune markers was investigated using the TIMER and TISIDB databases. We also performed gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis with the clusterProfiler package. Western blotting and RT-PCR were used to verify the protein level and mRNA level of CHPF in breast tissue and cell lines, respectively. Small interfering plasmids and lentiviral plasmids were constructed for transient and stable transfection of breast cancer cell lines MCF-7 and SUM1315, respectively, followed by proliferation-related functional assays, such as CCK8, EDU, clone formation assays; migration and invasion-related functional assays, such as wound healing assay and transwell assays. We also conducted a preliminary study of the mechanism.

Results

We observed that CHPF was significantly upregulated in breast cancer tissues and correlated with poor prognosis. CHPF gene transcriptional expression and methylation are associated with immune infiltration immune markers. CHPF promotes proliferation, migration, invasion of the breast cancer cell lines MCF-7 and SUM1315, and is significantly enriched in pathways associated with the ECM-receptor interaction and PI3K-AKT pathway.

Conclusion

CHPF transcriptional expression and DNA methylation correlate with immune infiltration and immune markers. Upregulation of CHPF in breast cancer promotes malignant behavior of cancer cells and is associated with poorer survival in breast cancer, possibly through ECM-receptor interactions and the PI3K-AKT pathway.

The specificity of the malarial VAR2CSA protein for chondroitin sulfate depends on 4-O-sulfation and ligand accessibility

Placental malaria infection is mediated by the binding of the malarial VAR2CSA protein to the placental glycosaminoglycan, chondroitin sulfate. Recombinant sub-fragments of VAR2CSA (rVAR2) have also been shown to bind specifically and with high affinity to cancer cells and tissues, suggesting the presence of a shared type of oncofetal chondroitin sulfate (ofCS) in the placenta and in tumors. However, the exact structure of ofCS and what determines the selective tropism of VAR2CSA remains poorly understood. In this study, ofCS was purified by affinity chromatography using rVAR2 and subjected to detailed structural analysis. We found high levels of N-acetylgalactosamine 4-O-sulfation (∼80-85%) in placenta- and tumor-derived ofCS. This level of 4-O-sulfation was also found in other tissues that do not support parasite sequestration, suggesting that VAR2CSA tropism is not exclusively determined by placenta- and tumor-specific sulfation. Here, we show that both placenta and tumors contain significantly more chondroitin sulfate moieties of higher molecular weight than other tissues. In line with this, CHPF and CHPF2, which encode proteins required for chondroitin polymerization, are significantly upregulated in most cancer types. CRISPR/Cas9 targeting of CHPF and CHPF2 in tumor cells reduced the average molecular weight of cell-surface chondroitin sulfate and resulted in a marked reduction of rVAR2 binding. Finally, utilizing a cell-based glycocalyx model, we showed that rVAR2 binding correlates with the length of the chondroitin sulfate chains in the cellular glycocalyx. These data demonstrate that the total amount and cellular accessibility of chondroitin sulfate chains impact rVAR2 binding and thus malaria infection.

CHPF Regulates the Aggressive Phenotypes of Hepatocellular Carcinoma Cells via the Modulation of the Decorin and TGF-β Pathways

Simple Summary

Altered extracellular chondroitin sulfate (CS) contributes to tumor progression in many cancers. CHPF is a key enzyme supporting the elongation of CS. Here we showed that CHPF was frequently downregulated in hepatocellular carcinoma (HCC) tumors compared with adjacent non-tumor tissues, and its downregulation was associated with poor overall survival. CHPF regulated aggressive phenotypes of HCC cells in vitro and in vivo, and the TGF-β pathway involved in the phenotypical changes. Mechanistically, CHPF modified CS on decorin (DCN), which could facilitate DCN accumulation surrounding HCC cells, and modulate activation of TGF-β pathway. Indeed, the expression of DCN were positively associated with CHPF levels in primary HCC tissue. The research proposed novel insights into the significance of CHPF, which modified DCN and modulated TGF-β signaling.

Abstract

Aberrant composition of glycans in the tumor microenvironment (TME) and abnormal expression of extracellular matrix proteins are hallmarks of hepatocellular carcinoma (HCC); however, the mechanisms responsible for establishing the TME remain unclear. We demonstrate that the chondroitin polymerizing factor (CHPF), an enzyme that mediates the elongation of chondroitin sulfate (CS), is a critical elicitor of the malignant characteristics of HCC as it modifies the potent tumor suppressor, decorin (DCN). CHPF expression is frequently downregulated in HCC tumors, which is associated with the poor overall survival of HCC patients. We observed that restoring CHPF expression suppressed HCC cell growth, migration, and invasion in vitro and in vivo. Mechanistic investigations revealed that TGF-β signaling is associated with CHPF-induced phenotype changes. We found that DCN, as a TGF-β regulator, is modified by CHPF, and that it affects the distribution of DCN on the surface of HCC cells. Importantly, our results confirm that CHPF and DCN expression levels are positively correlated in primary HCC tissues. Taken together, our results suggest that CHPF dysregulation contributes to the malignancy of HCC cells, and our study provides novel insights into the significance of CS, which affects DCN expression in the TME.

Identification of chondroitin polymerizing factor (CHPF) as tumor promotor in cholangiocarcinoma through regulating cell proliferation, cell apoptosis and cell migration

Cholangiocarcinoma (CCA) is a variety of biliary epithelial tumors involving intrahepatic, perihilar and distal bile duct. It is the most common malignant bile duct tumor in the liver and the second most common primary liver cancer, whose molecular mechanism not fully understood. Specifically, the relationship between CCA and chondroitin polymerizing factor (CHPF) is still not clear. In this study, detection of clinical specimens was performed to preliminarily study the role of CHPF in CCA. CCA cells with CHPF knockdown were constructed for in vitro study, which was also used in the construction of mice xenograft model for investigating the role of CHPF in the development of CCA. The results demonstrated that CHPF was significantly upregulated in CCA tissues compared with normal tissues. High expression of CHPF was correlated with more advanced tumor grade. Moreover, knockdown of CHPF significantly inhibited cell proliferation, cell migration, promoted cell apoptosis and arrest cell cycle in G2 phase in vitro, as well as suppressed tumor growth in vivo. In conclusion, CHPF was identified as a tumor promotor in the development and metastasis of CCA, which may provide a novel therapeutic target for the targeted therapy against CCA.

Chondroitin polymerizing factor promotes breast carcinoma cell proliferation, invasion and migration and affects expression of epithelial-mesenchymal transition-related markers

Chondroitin polymerizing factor (CHPF) plays an important role in the development of certain malignant tumors. However, the role of CHPF in breast carcinoma (BRCA) and its underlying mechanism are still not fully elucidated. Expression profiles for CHPF in BRCA tissues were retrieved from The Cancer Genome Atlas database and used for prognostic analysis. Cell viability, invasion and migration were measured in vitro using MCF7 and MDA‐MB‐231 cell lines upon knockdown or over‐expression of CHPF. Bioinformatic analysis showed that CHPF was substantially upregulated in BRCA tissues, and a quantitative reverse transcriptase‐PCR was performed to confirm its upregulation in BRCA cells. High expression of CHPF was observed to be significantly associated with pathologic stage, metastasis and worse prognosis. We also observed that depletion of CHPF significantly inhibited cell proliferative, invasive and migratory abilities, whereas overexpression of CHPF exerted the opposite effects. Furthermore, analysis of the GEPIA database revealed that CHPF expression is positively correlated with the epithelial–mesenchymal transition‐related markers vimentin, Snail, Slug and motion‐related protein matrix metallopeptidase 2; these findings were confirmed via western blotting. Our data suggest that CHPF may contribute to BRCA progression by modulating epithelial–mesenchymal transition‐related markers and matrix metallopeptidase 2 expression.