BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide, characterized by high morbidity, high mortality, and poor prognosis. Collagen triple helix repeat containing 1 (CTHRC1) has been shown to be highly expressed in various cancers. However, its biological functions, potential role as a biomarker, and its relationship with immune infiltrates in HNSCC remain unclear. Our principal objective was to analyze CTHRC1 expression, its prognostic implications, biological functions, and its effects on the immune system in HNSCC patients using bioinformatics analysis.
METHODS: The expression matrix was obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). CTHRC1 expression in HNSCC was analyzed between tumor and adjacent normal tissues, different stages were compared, and its impact on clinical prognosis was assessed using Kaplan-Meier analysis. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Variation Analysis (GSVA) were employed for enrichment analysis. The Search Tool for the Retrieval of Interacting Genes database (STRING) was used to analyze protein-protein interactions. Pearson correlation tests were used to investigate the association between CTHRC1 expression and immune checkpoints. The correlation between CTHRC1 and immune infiltration was investigated using CIBERSORT, TIMER, and ESTIMATE.
RESULTS: Compared to adjacent normal tissues, CTHRC1 was found to be highly overexpressed in tumors. Increased expression of CTHRC1 was more evident in the advanced stage of HNSCC and predicted a poor prognosis. Most genes related to CTHRC1 in HNSCC were enriched in physiological functions of Extracellular matrix(ECM) and tumor. Furthermore, several immune checkpoints, such as TNFSF4 and CD276 have been shown to be associated with CTHRC1 expression. Notably, the level of CTHRC1 expression correlated significantly with immune infiltration levels, particularly activated macrophages in HNSCC.
CONCLUSIONS: High expression of CTHRC1 predicts poor prognosis and is associated with immune infiltration in HNSCC, confirming its utility as a tumor marker for HNSCC.
BACKGROUND: Not applicable. All data are from public databases and do not contain any clinical trials.

UNASSIGNED: In recent years, abnormal expression of collagen triple helix repeat containing 1 (CTHRC1) has been found in some tumors, closely related to the poor prognosis of cancer patients. However, the clinical significance of CTHRC1 in gliomas is not completely understood.
UNASSIGNED: We investigated the expression, prognostic value, and potential biological function of CTHRC1 in different types of gliomas through bioinformatics analysis and experimental verification.
UNASSIGNED: Bioinformatics analysis revealed several key findings regarding the expression and clinical significance of CTHRC1 in gliomas. First, the analysis demonstrated a positive correlation between CTHRC1 expression and the World Health Organization (WHO) grading of gliomas, a relationship that was validated through immunohistochemistry experiments. In addition, a trend was observed in which CTHRC1 expression increased with the extent of glioma invasion, as supported by Western blot experiments. Subsequent bioinformatics analysis identified the mesenchymal subtype of gliomas as having the highest levels of CTHRC1 expression, a finding reinforced by immunohistochemical staining. Moreover, high CTHRC1 expression was associated with poor prognosis in gliomas and emerged as an independent prognostic factor, with varying impacts on prognosis between low-grade gliomas (LGGs) and glioblastoma (GBM) subgroups. Notably, comparative analysis unveiled distinct patterns of immune infiltration of CTHRC1 in LGG and GBM. Furthermore, alterations in copy number variations and DNA methylation were identified as potential mechanisms underlying elevated CTHRC1 levels in gliomas. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that CTHRC1 and its associated genes mainly function in the extracellular matrix and participate in tumor-related signaling pathways.
UNASSIGNED: The CTHRC1 has shown significant clinical utility as a prognostic marker and mesenchymal subtype marker of glioma.

Fibrosis, a pathological state characterized by the excessive accumulation of extracellular matrix components, is primarily driven by the overactivation of fibroblasts. This condition becomes particularly pronounced under chronic inflammatory conditions. Fibrosis can occur in several tissues throughout the body. Among the notable discoveries in the study of fibrosis is the role of Collagen Triple Helix Repeat Containing-1 (CTHRC1), a protein that has emerged as a critical regulator in the fibrotic process. CTHRC1 is rapidly expressed on the outer membrane of fibroblasts and intimal smooth muscle cells following vascular injury, such as that induced by balloon angioplasty. This expression denotes the organism efforts to repair and restructure compromised tissue, signifying a critical component of the tissue repair mechanism in reaction to fibrosis. It plays a pivotal role in promoting cell migration and aiding tissue repair post-injury, contributing significantly to various pathophysiological processes including revascularization, bone formation, developmental morphological changes, inflammatory arthritis, and the progression of cancer. Significantly, researchers have observed marked expression of CTHRC1 across a variety of fibrotic conditions, closely associating it with the progression of the disease. Intervention with CTHRC1 can affect the occurrence and progression of fibrosis. This review aims to comprehensively explore the role and underlying mechanisms of CTHRC1 in fibrotic diseases, highlighting its potential as a key target for therapeutic interventions.

Lung adenocarcinoma (LUAD) is the predominant subtype within the spectrum of lung malignancies. CTHRC1 has a pro-oncogenic role in various cancers. Here, we observed the upregulation of CTHRC1 in LUAD, but its role in cisplatin resistance in LUAD remains unclear. Bioinformatics analysis was employed to detect CTHRC1 and SRY-related HMG-box 4 (SOX4) expression in LUAD. Gene Set Enrichment Analysis predicted the enriched pathways related to CTHRC1. JASPAR and MotifMap databases predicted upstream transcription factors of CTHRC1. Pearson analysis was conducted to analyze the correlation between genes of interest. The interaction and binding relationship between CTHRC1 and SOX4 were validated through dual-luciferase and chromatin immunoprecipitation assays. Quantitative real-time polymerase chain reaction determined the expression of CTHRC1 and SOX4 genes. CCK-8 was performed to assess cell viability and calculate IC50 value. Flow cytometry examined the cell cycle. Comet assay and western blot assessed DNA damage. CTHRC1 and SOX4 were upregulated in LUAD. CTHRC1 exhibited higher expression in cisplatin-resistant A549 cells compared to cisplatin-sensitive A549 cells. Knockdown of CTHRC1 enhanced DNA damage during cisplatin treatment and increased the sensitivity of LUAD cells to cisplatin. Additionally, SOX4 modulated DNA damage repair (DDR) by activating CTHRC1 transcriptional activity, promoting cisplatin resistance in LUAD cells. SOX4 regulated DDR by activating CTHRC1, thereby enhancing cisplatin resistance in LUAD cells. The finding provides a novel approach to address clinical cisplatin resistance in LUAD, with CTHRC1 possibly serving as a candidate for targeted therapies in addressing cisplatin resistance within LUAD.

Tumor-associated macrophages (TAMs) represent a key factor in the tumor immune microenvironment (TME), exerting significant influence over tumor migration, invasion, immunosuppressive features, and drug resistance. Collagen triple helix repeat containing 1 (CTHRC1), a 30 KDa protein which was secreted during the tissue-repair process, is highly expressed in several malignant tumors, including colorectal cancer (CRC). Previous studies demonstrated that CTHRC1 expression in TAMs was positively correlated to M2 macrophage polarization and liver metastasis, while our discovery suggesting a novel mechanism that CTHRC1 secreted from cancer cell could indirectly interplay with TAMs. In this study, the high expression level of CTHRC1 was evaluated in CRC based on GEO and TCGA databases. Further, CTHRC1 was detected high in all stages of CRC patients by ELISA and was correlated to poor prognosis. Multispectral imaging of IHC demonstrated that M2 macrophage infiltration was increased accompanied with CTHRC1 enrichment, suggesting that CTHRC1 may have chemotactic effect on macrophages. In vitro, CTHRC1 could have chemotactic ability of macrophage in the presence of HT-29 cell line. Cytokine microarray revealed that CTHRC1 could up-regulate the CCL15 level of HT-29, pathway analysis demonstrated that CTHRC1 could regulate CCL15 by controlling the TGFβ activation and Smad phosphorylation level. In vivo, knocking down of CTHRC1 from CT-26 also inhibits tumor formation. In conclusion, CTHRC1 could promote the chemotactic ability of macrophages by up-regulating CCL15 via TGFβ/Smad pathway; additionally, a high level of CTHRC1 could promote macrophage\'s M2 polarization. This discovery may be related to tumor immune tolerance and tumor immunotherapy resistance in CRC. KEY MESSAGES: CTHRC1 promotes CRC progression by up-regulating CCL15 via TGF-β/Smad pathways to further recruit tumor-associated macrophages. By the means of autocrine or paracrine, CTHRC1 can indeed promote macrophage chemotaxis and enhance the infiltration of macrophages in tumor tissues but in the presence of tumor cells. CAFs were another source of CTHRC1, indicating CTHRC1 can infiltrate tumor islet as well as the stomal and be secreted from both tumor cells and CAFs. This study validated CTHRC1 as a potential immune therapy target CRC.

Anaplastic thyroid carcinoma (ATC) is an extremely aggressive tumor with a high mortality rate and poor prognosis. However, the pathogenesis of ATC is complex and poorly understood, and the effective treatment options are limited. Analysis of data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases showed that collagen triple helix repeat containing-1 (CTHRC1) was specifically upregulated in ATC tissues and was negatively correlated with overall survival (OS) in thyroid carcinoma patients. In vitro knockdown of CTHRC1 dramatically decreased the proliferation, migration, and invasion abilities of ATC cells, and in vivo studies in BALB/c nude mice confirmed that CTHRC1 knockdown significantly inhibited tumor growth. Mechanistically, CTHRC1 knockdown was found to suppress the Wnt/β-catenin pathway and epithelial-mesenchymal transition (EMT) at the protein level. These findings suggest that CTHRC1 promotes the progression of ATC via upregulating tumor cell proliferation, migration, and invasion, which may be achieved by activating the Wnt/β-catenin pathway and EMT.

Fluoride is a widespread pollutant in the environment. There is a high risk of developing skeletal fluorosis from excessive fluoride exposure. Skeletal fluorosis has different phenotypes (including osteosclerotic, osteoporotic and osteomalacic) under the same fluoride exposure and depends on dietary nutrition. However, the existing mechanistic hypothesis of skeletal fluorosis cannot well explain the condition\'s different pathological manifestations and their logical relation with nutritional factors. Recent studies have shown that DNA methylation is involved in the occurrence and development of skeletal fluorosis. DNA methylation is dynamic throughout life and may be affected by nutrition and environmental factors. We speculated that fluoride exposure leads to the abnormal methylation of genes related to bone homeostasis under different nutritional statuses, resulting in different skeletal fluorosis phenotypes. The mRNA-Seq and target bisulfite sequencing (TBS) result showed differentially methylated genes in rats with different skeletal fluorosis types. The role of the differentially methylated gene Cthrc1 in the formation of different skeletal fluorosis types was explored in vivo and in vitro. Under normal nutritional conditions, fluoride exposure led to hypomethylation and high expression of Cthrc1 in osteoblasts through TET2 demethylase, which promoted osteoblast differentiation by activating Wnt3a/β-catenin signalling pathway, and participated in the occurrence of osteosclerotic skeletal fluorosis. Meanwhile, the high CTHRC1 protein expression also inhibited osteoclast differentiation. Under poor dietary conditions, fluoride exposure led to hypermethylation and low expression of Cthrc1 in osteoblasts through DNMT1 methyltransferase, and increased the RANKL/OPG ratio, which promoted the osteoclast differentiation and participated in the occurrence of osteoporotic/osteomalacic skeletal fluorosis. Our study expands the understanding of the role of DNA methylation in regulating the formation of different skeletal fluorosis types and provides insights into new prevention and treatment strategies for patients with skeletal fluorosis.

UNASSIGNED: CTHRC1 is highly expressed in various cancers.
UNASSIGNED: The aim of the study was to study the role of CTHRC1 played in lung adenocarcinoma (LUAD) development and its underlying biological functions.
UNASSIGNED: Enriched pathways and upstream transcription factors of CTHRC1 were explored by bioinformatics analysis. Dual-luciferase assay and Chromatin immunoprecipitation assay were used to verify the binding relationship between CTHRC1 and HOXB9. CCK-8 was utilized to detect cell viability. Expression levels of CTHRC1, HOXB9, and angiogenesis-related genes were assessed by quantitative real time-polymerase chain reaction. Angiogenesis assay was used to detect angiogenesis ability. Quantitative analysis of metabolites were used to detect the accumulation of neutral lipids, the levels of free fatty acids (FAs), and glycerol. Western blot was conducted to measure expression of metabolic enzymes of FA.
UNASSIGNED: CTHRC1 was enriched in FA metabolic pathway, which was positively correlated and bound with HOXB9. CTHRC1 and HOXB9 expression was remarkably up-regulated in LUAD cells. Overexpression of CTHRC1 promoted FA metabolic pathway and angiogenesis, and FA inhibitor Orlistat restored it to NC group level. Meanwhile, CTHRC1 affected LUAD angiogenesis by activating HOXB9 to regulate FA metabolism.
UNASSIGNED: This study found that activation of CTHRC1 by HOXB9 induces angiogenesis by mediating FA metabolism. CTHRC1 may be a potential target for LUAD diagnosis.

Cardiac fibroblasts are crucial for scar formation and cardiac repair after myocardial infarction (MI). Collagen triple helix repeat containing 1 (CTHRC1), an extracellular matrix protein, is involved in the pathogenesis of vascular remodeling, bone formation, and tumor progression. However, the role and underlying mechanism of CTHRC1 in post-MI wound repair are not fully clear. Bioinformatics analysis demonstrated CTHRC1 up-regulation in cardiac fibroblasts after ischemic cardiac injury. Serum levels of CTHRC1 were increased in MI mice and CTHRC1 expression was up-regulated in cardiac fibroblasts after MI. In vitro results showed that the induction of CTHRC1 expression in cardiac fibroblasts was mediated by canonical TGFβ1-Smad2/3 signaling axis. Moreover, CTHRC1 improved wound healing and boosted cardiac fibroblast activation in vitro. Cthrc1 deficiency aggravated cardiac function and reduced collagen deposition as well as increased mortality attributable to cardiac rupture after MI. Consistent with above phenotypes, reduced the levels of myocardial CD31, α-smooth muscle actin, collagen I, and collagen III was observed, whereas myocardial expression of matrix metalloproteinase 2 and matrix metalloproteinase 9 were increased in Cthrc1 knockout mice post-MI. Above effects could be partly reversed by rCTHRC1 protein or rWNT5A protein. Our study indicates that cardiac fibroblast-derived, canonical TGFβ1-Smad2/3-dependent CTHRC1 could improve wound repair and prevent cardiac rupture after MI via selectively activating non-canonical WNT5A-PCP signaling pathway.

Asthma is a chronic inflammatory disease characterized by airway remodeling and lung inflammation. Collagen triple helix repeat containing 1 (CTHRC1), a glycoprotein, is involved in multiple pathological processes, including inflammation and fibrosis. However, the function of CTHRC1 in asthma remains unclear. In the present study, the mouse asthma model was successfully generated by sensitizing and challenging mice with ovalbumin (OVA). CTHRC1 expression at both RNA and protein levels was significantly upregulated in lung tissues of asthmatic mice. Asthmatic mice exhibited significant airway remodeling as evidenced by increased bronchial wall and smooth muscle cell layer thickness, goblet cell hyperplasia and collagen deposition, and epithelial-mesenchymal transition (EMT), but those characteristics were reversed by CTHRC1 silencing. The cell model with transforming growth factor-β1 (TGF-β1) induction in bronchial epithelial cells (BEAS-2B) was conducted to verify the effects of CTHRC1 on EMT, a classic mechanism that mediates airway remodeling. The results showed that TGF-β1 stimulation increased CTHRC1 expression, and CTHRC1 knockdown inhibited TGF-β1-induced EMT. OVA-treated mice also showed increased inflammatory cell infiltration and the production of OVA-specific immunoglobulin E (IgE), interleukin (IL)-4, IL-5, and IL-13, which were decreased by CTHRC1 downregulation. The effects of CTHRC1 on OVA-induced airway inflammation were further determined by treating BEAS-2B cells with IL-13, in which CTHRC1 knockdown reduced the IL-13-induced secretion of pro-inflammatory factors, including IL-4 and IL-5. In conclusion, these results indicate that CTHRC1 silencing attenuates asthmatic airway remodeling and inflammation in vivo and in vitro, suggesting that CTHRC1 may be a potential target for asthma treatment.