Identification of BGN positive fibroblasts as a driving factor for colorectal cancer and development of its related prognostic model combined with machine learning.

BACKGROUND: Numerous studies have indicated that cancer-associated fibroblasts (CAFs) play a crucial role in the progression of colorectal cancer (CRC). However, there are still many unknowns regarding the exact role of CAF subtypes in CRC. METHODS: The data for this study were obtained from bulk, single-cell, and spatial transcriptomic sequencing data. Bioinformatics analysis, in vitro experiments, and machine learning methods were employed to investigate the functional characteristics of CAF subtypes and construct prognostic models. RESULTS: Our study demonstrates that Biglycan (BGN) positive cancer-associated fibroblasts (BGN + Fib) serve as a driver in colorectal cancer (CRC). The proportion of BGN + Fib increases gradually with the progression of CRC, and high infiltration of BGN + Fib is associated with poor prognosis in terms of overall survival (OS) and recurrence-free survival (RFS) in CRC. Downregulation of BGN expression in cancer-associated fibroblasts (CAFs) significantly reduces migration and proliferation of CRC cells. Among 101 combinations of 10 machine learning algorithms, the StepCox[both] + plsRcox combination was utilized to develop a BGN + Fib derived risk signature (BGNFRS). BGNFRS was identified as an independent adverse prognostic factor for CRC OS and RFS, outperforming 92 previously published risk signatures. A Nomogram model constructed based on BGNFRS and clinical-pathological features proved to be a valuable tool for predicting CRC prognosis. CONCLUSION: In summary, our study identified BGN + Fib as drivers of CRC, and the derived BGNFRS was effective in predicting the OS and RFS of CRC patients.

Neonatal Achilles Tendon Microstructure is Negatively Impacted by Decorin and Biglycan Knockdown After Injury and During Development.

Interest in studying neonatal development and the improved healing response observed in neonates is increasing, with the goal of using this work to create better therapeutics for tendon injury. Decorin and biglycan are two small leucine-rich proteoglycans that play important roles in collagen fibrillogenesis to develop, maintain, and repair tendon structure. However, little is known about the roles of decorin and biglycan in early neonatal development and healing. The goal of this study was to determine the effects of decorin and biglycan knockdown on Achilles tendon structure and mechanics during neonatal development and recovery of these properties after injury of the neonatal tendon. We hypothesized that knockdown of decorin and biglycan would disrupt the neonatal tendon developmental process and produce tendons with impaired mechanical and structural properties. We found that knockdown of decorin and biglycan in an inducible, compound decorin/biglycan knockdown model, both during development and after injury, in neonatal mice produced tendons with reduced mechanical properties. Additionally, the collagen fibril microstructure resembled an immature tendon with a large population of small diameter fibrils and an absence of larger diameter fibrils. Overall, this study demonstrates the importance of decorin and biglycan in facilitating tendon growth and maturation during neonatal development.

Molecular cues for immune cells from small leucine-rich repeat proteoglycans in their extracellular matrix-associated and free forms.

In this review we highlight emerging immune regulatory functions of lumican, keratocan, fibromodulin, biglycan and decorin, which are members of the small leucine-rich proteoglycans (SLRP) of the extracellular matrix (ECM). These SLRPs have been studied extensively as collagen-fibril regulatory structural components of the skin, cornea, bone and cartilage in homeostasis. However, SLRPs released from a remodeling ECM, or synthesized by activated fibroblasts and immune cells contribute to an ECM-free pool in tissues and circulation, that may have a significant, but poorly understood foot print in inflammation and disease. Their molecular interactions and the signaling networks they influence also require investigations. Here we present studies on the leucine-rich repeat (LRR) motifs of SLRP core proteins, their evolutionary and functional relationships with other LRR pathogen recognition receptors, such as the toll-like receptors (TLRs) to bring some molecular clarity in the immune regulatory functions of SLRPs. We discuss molecular interactions of fragments and intact SLRPs, and how some of these interactions are likely modulated by glycosaminoglycan side chains. We integrate findings on molecular interactions of these SLRPs together with what is known about their presence in circulation and lymph nodes (LN), which are important sites of immune cell regulation. Recent bulk and single cell RNA sequencing studies have identified subsets of stromal reticular cells that express these SLRPs within LNs. An understanding of the cellular source, molecular interactions and signaling consequences will lead to a fundamental understanding of how SLRPs modulate immune responses, and to therapeutic tools based on these SLRPs in the future.

Investigating the temporal roles of decorin and biglycan in tendon healing.

The small leucine-rich proteoglycans, decorin and biglycan, are minor components of the tendon extracellular matrix that regulate fibrillogenesis and matrix assembly. Our study objective was to define the temporal roles of decorin and biglycan during tendon healing using inducible knockout mice to include genetic knockdown at specific phases of healing: time of injury, the proliferative phase, and the remodeling phase. We hypothesized that knockdown of decorin or biglycan would adversely affect tendon healing, and that by prescribing the timing of knockdown, we could elucidate the temporal roles of these proteins during healing. Contrary to our hypothesis, decorin knockdown did not affect tendon healing. However, when biglycan was knocked down, either alone or coupled with decorin, tendon modulus was increased relative to wild-type mice, and this finding was consistent among all induction timepoints. At 6 weeks postinjury, we observed increased expression of genes associated with the extracellular matrix and growth factor signaling in the biglycan knockdown and compound decorin-biglycan knockdown tendons. Interestingly, these groups demonstrated opposing trends in gene expression as a function of knockdown-induction timepoint, highlighting distinct temporal roles for decorin and biglycan. In summary, this study finds that biglycan plays multiple functions throughout tendon healing, with the most impactful, detrimental role likely occurring during late-stage healing. Statement of clinical importance: This study helps to define the molecular factors that regulate tendon healing, which may aid in the development of new clinical therapies.

Long noncoding RNA ZEB1-AS1 attenuates ferroptosis of gastric cancer cells through modulating miR-429/BGN axis.

Gastric cancer (GC) is the fifth utmost common malignant cancer type globally, in which ferroptosis acts a critical function in the progress of GC. Long noncoding RNA ZEB1-AS1 has been recognized in numerous cancers, but the role of ZEB1-AS1 in ferroptosis remains obscure. Hence, we investigated the efficacy of ZEB1-AS1 on ferroptosis of GC cells. The cell growth and viability were analyzed via cell counting kit assay and xenograft tumor model in vivo and in vitro, respectively. The RNA and protein expression were measured by qRT-PCR and western blot analysis assay, respectively. The levels of Fe2+ , malondialdehyde (MDA), and lipid reactive oxygen species (ROS) were tested to determine ferroptosis. The erastin and RSL3 were used to induce ferroptosis. The mechanism was analyzed via luciferase reporter gene and RIP assays. The treatment of ferroptosis inducer Erastin and RSL3 suppressed the viability of GC cells and the ZEB1-AS1 overexpression rescued the phenotype in the cells. The levels of Fe2+ , MDA, and ROS were enhanced through the depletion of ZEB1-AS1 in Erastin/RSL3 treated GC cells. ZEB1-AS1 directly sponged miR-429 in GC cells and miR-429 targeted BGN in GC cells, and the inhibition of miR-429 rescued ZEB1-AS1 depletion-inhibited BGN expression. We validated that miR-429 induced and BGN-repressed ferroptosis in cancer cells. The BGN overexpression and miR-429 suppression could reverse the efficacy of ZEB1-AS1 on proliferation and ferroptosis in cancer cells. The expression of ZEB1-AS1 and BGN was enhanced and miR-429 expression was decreased in clinical GC tissues. ZEB1-AS1 attenuated ferroptosis of cancer cells by modulating miR-429/BGN axis.

Single-Cell Spatial Analysis Identifies Regulators of Brain Tumor-Initiating Cells.

Glioblastomas (GBM) are aggressive brain tumors with extensive intratumoral heterogeneity that contributes to treatment resistance. Spatial characterization of GBMs could provide insights into the role of the brain tumor microenvironment in regulating intratumoral heterogeneity. Here, we performed spatial transcriptomic and single-cell analyses of the mouse and human GBM microenvironment to dissect the impact of distinct anatomical regions of brains on GBM. In a syngeneic GBM mouse model, spatial transcriptomics revealed that numerous extracellular matrix (ECM) molecules, including biglycan, were elevated in areas infiltrated with brain tumor-initiating cells (BTIC). Single-cell RNA sequencing and single-cell assay for transposase-accessible chromatin using sequencing showed that ECM molecules were differentially expressed by GBM cells based on their differentiation and cellular programming phenotypes. Exogeneous biglycan or overexpression of biglycan resulted in a higher proliferation rate of BTICs, which was associated mechanistically with low-density lipoprotein receptor-related protein 6 (LRP6) binding and activation of the Wnt/ß-catenin pathway. Biglycan-overexpressing BTICs developed into larger tumors and displayed mesenchymal phenotypes when implanted intracranially in mice. This study points to the spatial heterogeneity of ECM molecules in GBM and suggests that the biglycan-LRP6 axis could be a therapeutic target to curb tumor growth. SIGNIFICANCE: Characterization of the spatial heterogeneity of glioblastoma identifies regulators of brain tumor-initiating cells and tumor growth that could serve as candidates for therapeutic interventions to improve the prognosis of patients.

Knockdown of biglycan reveals an important role in maintenance of structural and mechanical properties during tendon aging.

Biglycan, a small leucine-rich proteoglycan (SLRP), is involved in collagen fibrillogenesis and also acts as a signaling molecule. Although decorin has been considered as the primary SLRP in developing and maintaining tendon structure and mechanics, more recent work using inducible knockdown models suggests that biglycan is involved in tendon homeostasis. The purpose of the study was to determine the role of biglycan in tendon homeostasis to maintain mechanical and structural integrity in aged mice. Aged (485 days old) female Bgn+/+ control (wild type [WT], n = 16) and 16 bitransgenic conditional Bgnflox/flox mice (I-Bgn-/- , n = 16) with a tamoxifen-inducible Cre (driven by ROSA) were utilized. After biglycan knockdown, the transgenic model demonstrated effective knockdown of the target gene without any compensation from other SLRPs or type I collagen. Patellar tendon cellularity was not modified after biglycan knockdown. However, biglycan knockdown had an impact on collagen fibrillogenesis with a higher percentage of small diameter fibrils (25-45 nm) and a lower percentage of medium size fibrils (150-165 nm) in I-Bgn-/- tendons. Biglycan knockdown also induced a reduction in the midsubstance modulus and maximum stress compared to WT. Stress relaxation was reduced at 4% strain in I-Bgn-/- tendons but no changes were observed in dynamic modulus and tan delta. As in mature tendons (120 days old), this study showed significant effects of biglycan knockdown on mechanical and structural properties of aged tendons only 30 days after knockdown. These data suggest that biglycan has a major role in maintaining homeostasis in aged tendon.

Dissecting the role of cancer-associated fibroblast-derived biglycan as a potential therapeutic target in immunotherapy resistance: A tumor bulk and single-cell transcriptomic study.

INTRODUCTION: Cancer-associated fibroblasts (CAFs) are correlated with the immunotherapy response. However, the culprits that link CAFs to immunotherapy resistance are still rarely investigated in real-world studies. OBJECTIVES: This study aims to systematically assess the landscape of fibroblasts in cancer patients by combining single-cell and bulk profiling data from pan-cancer cohorts. We further sought to decipher the expression, survival predictive value and association with immunotherapy response of biglycan (BGN), a proteoglycan in the extracellular matrix, in multiple cohorts. METHODS: Pan-cancer tumor bulks and 27 single-cell RNA sequencing cohorts were enrolled to investigate the correlations and crosstalk between CAFs and tumor or immune cells. Specific secreting factors of CAFs were then identified by expression profiling at tissue microdissection, isolated primary fibroblasts and single-cell level. The role of BGN was further dissected in additional three bulk and five single-cell profiling datasets from immunotherapy cohorts and validated in real-world patients who have received PD-1 blockade using immunohistochemistry and immunofluorescence. RESULTS: CAFs were closely correlated with immune components. Frequent crosstalk between CAFs and other cells was revealed by the CellChat analysis. Single-cell regulatory network inference and clustering identified common and distinct regulators for CAFs across cancers. The BGN was determined to be a specific secreting factor of CAFs. The BGN served as an unfavourable indicator for overall survival and immunotherapy response. In the real-world immunotherapy cohort, patients with high BGN levels presented a higher proportion of poor response compared with those with low BGN (46.7% vs. 11.8%) and a lower level of infiltrating CD8+ T cells was also observed. CONCLUSIONS: We highlighted the importance of CAFs in the tumor microenvironment and revealed that the BGN, which is mainly derived from CAFs, may be applicable in clinical practice and serve as a therapeutic target in immunotherapy resistance.

IPSC reprogramming of two patients with spondyloepimetaphyseal dysplasia (SEMD, biglycan type).

Hemizygous missense variants in the X-linked BGN gene, encoding the extracellular matrix protein biglycan, cause spondyloepimetaphyseal dysplasia (SEMD, biglycan type), which is clinically characterized by short stature, brachydactyly and osteoarthritis. Little is known about the pathomechanisms underlying SEMD, biglycan type. IPSC-derived chondrocyte disease models have been shown to exhibit several key aspects of known disease mechanisms of skeletal dysplasias and are therefore considered highly suitable human disease models to study SEMD, biglycan type. Prior to creating iPSC-chondrocytes, dermal fibroblasts of two male patients with SEMD, biglycan type, carrying the p.Gly259Val variant were successfully reprogrammed into iPSCs using the CytoTuneTM-iPS 2.0 Sendai Kit (Invitrogen).

Generation of an induced pluripotent stem cell (iPSC) line (BBANTWi009-A) from a Meester-Loeys syndrome patient carrying a BGN mutation.

Meester-Loeys syndrome (MRLS) is an X-linked syndromic form of thoracic aortic aneurysm and dissection. Here, we report an iPSC line (BBANTWi009-A) of a boy carrying a hemizygous BGN mutation (chrX:153502980-153530518del, GRCh38) causing MRLS. iPSCs were generated from dermal fibroblasts by reprogramming with the Cytotune®-iPS 2.0 Sendai Reprogramming Kit (Invitrogen). The generated iPSCs showed a normal karyotype, expressed pluripotency markers, were differentiated into the three germ layers and carried the original genotype.

Evaluation of the In Vitro and In Vivo Effects of Biglycan in Innate Immunity.

Biglycan, a small leucine-rich proteoglycan (SLRP), is a crucial component of the extracellular matrix (ECM) associated with the maintenance of tissue homeostasis. In response to tissue damage, the ECM-derived soluble form of biglycan acts as a danger signal by triggering an inflammatory response via the toll-like receptor (TLR)2/TLR4 in macrophages and dendritic cells. The impact and signaling mechanism of biglycan in innate immunity is better understood with the use of specific and reliable research tools and investigation techniques. Accordingly, our lab has established explicit and detailed experimental protocols to examine the in vitro and in vivo effects of biglycan in cellular immune responses. To evaluate the in vitro effects of biglycan on macrophage activation, a comprehensive protocol that makes use of murine peritoneal macrophages has been described. Further, to study the in vivo effects of biglycan, a method that uses a pLIVE vector to generate transgenic mice transiently overexpressing human biglycan is detailed. A step-by-step protocol for analyzing the effects of soluble biglycan overexpression in transgenic mice is explained under the following sections: (1) construction of pLIVE-hBGN plasmid, (2) intravenous delivery of transgenic vector, (3) identification of hBGN transgene in hepatocytes (4) detection of transgenic biglycan protein in the plasma of transgenic mice, and (5) evaluation of the presence and pro-inflammatory effects of transgenic biglycan in extrahepatic mouse tissues.

Relationship of biglycan and decorin expression with clinicopathological features and prognosis in patients with oral squamous cell carcinoma.

OBJECTIVE: This study focused on investigating relation between biglycan (BGN) and decorin (DCN) expression and prognostic outcome for oral squamous cell carcinoma (OSCC) cases. MATERIAL AND METHODS: BGN and DCN mRNA and protein expression was detected by qRT-PCR and Western-blotting (WB) assays from 31 OSCC samples as well as healthy samples. This work harvested 101 paraffin-embedded OSCC together with 30 healthy samples, and conducted immunohistochemical (IHC) staining for assessing pathological changes. Association of DCN with BGN within OSCC was explored by Spearman's analysis. Survival rate was explored by Kaplan-Meier (KM) approach. Multivariate analysis was conducted by Cox regression. RESULTS: WB and qRT-PCR results showed BGN up-regulation (p < 0.001, p < 0.0001) whereas DCN down-regulation (p < 0.0001, p < 0.0001) with fresh OSCC tissues; the expression of BGN and DCN associated with the OSCC histopathological grade. IHC results suggested elevated BGN level (p < 0.0001) whereas DCN down-regulation (p < 0.0001) with paraffin embedded OSCC tissues. The expression of BGN and DCN associated with histopathologic grades and tumor stage of OSCC. The result of Spearman's analysis demonstrated significant association between the expression of BGN and DCN in OSCC. Survival analysis revealed that patients with higher BGN/lower DCN level showed poor overall survival (OS) as well as tumor-specific survival (TSS). Multivariate analysis proved that BGN and DCN independently predicted the prognosis of OS and TSS. CONCLUSION: BGN and DCN expression levels can be adopted for predicting OSCC prognostic outcome.

Expression and the Prognostic Value of Biglycan in Gastric Cancer.

Background: Biglycan (BGN) is a family member of small leucine-rich repeat proteoglycans. High expression of BGN might enhance the invasion and metastasis in some types of tumors. Here, the prognostic significance of BGN was evaluated in gastric cancer. Material and Methods. Two independent Gene Expression Omnibus (GEO) gastric cancer microarray datasets (n = 64 and n = 432) were collected for this study. Kaplan-Meier analysis was applied to evaluate if BGN impacts the outcomes of gastric cancer. Protein-protein interaction (PPI) analysis was performed on gastric cancer-related genes and BGN targets, and those interactions with confidence interval (CI) ≥ 0.7 were chosen to construct a PPI network. The gene set enrichment analysis (GSEA) was used to explore BGN and cancer-related gene signatures. Gene Transcription Regulation Database (GTRD) and ALGGEN-PROMO predicted the transcription factor binding sites (TFBSs) of the BGN promoter. BGN protein level in gastric cancer tissue was determined by immunohistochemistry (IHC). Bioinformatic analysis predicted the putative TFs of BGN. Results: For gastric cancer, the mRNA expression level of BGN in tumor tissue was significantly higher than that in normal tissue. Kaplan-Meier analysis showed that higher expression of BGN mRNA was significantly associated with more reduced recurrence-free survival (RFS). GSEA results suggested that BGN was significantly enriched in gene signatures related to metastasis and poor prognosis, revealing that BGN might be associated with cell proliferation, poor differentiation, and high invasiveness of gastric cancer. Meanwhile, the putative TFs, including AR, E2F1, and TCF4, were predicted by bioinformatic analysis and also significantly correlated with expression of BGN in mRNA levels. Conclusion: High expression of BGN mRNA was significantly related to poor prognosis, which suggested that BGN was a potential prognostic biomarker and therapeutic target of gastric cancer.

Biglycan as a potential regulator of tumorgenicity and immunogenicity in K-RAS-transformed cells.

The extracellular matrix component biglycan (BGN) plays an essential role in various physiological and pathophysiological processes. A deficient BGN expression associated with reduced immunogenicity was found in HER-2/neu-overexpressing cells. To determine whether BGN is suppressed by oncogene-driven regulatory networks, the expression and function of BGN was analyzed in murine and human BGNlow/BGNhigh K-RASG12V-transformed model systems as well as in different patients' datasets of colorectal carcinoma (CRC) lesions. K-RAS-mutated CRC tissues expressed low BGN mRNA and protein levels when compared to normal colon epithelial cells, which was associated with a reduced patients' survival. Transfection of BGN in murine and human BGNlow K-RAS-expressing cells resulted in a reduced growth and migration of BGNhigh vs BGNlow K-RAS cells. In addition, increased MHC class I surface antigens as a consequence of an enhanced antigen processing machinery component expression was found upon restoration of BGN, which was confirmed by RNA-sequencing of BGNlow vs. BGNhigh K-RAS models. Furthermore, a reduced tumor formation of BGNhigh versus BGNlow K-RAS-transformed fibroblasts associated with an enhanced MHC class I expression and an increased frequency of tumor-infiltrating lymphocytes in tumor lesions was found. Our data provide for the first time an inverse link between BGN and K-RAS expression in murine and human K-RAS-overexpressing models and CRC lesions associated with altered growth properties, reduced immunogenicity and worse patients' outcome. Therefore, reversion of BGN might be a novel therapeutic option for K-RAS-associated malignancies.

The role of biglycan in the healthy and thoracic aneurysmal aorta.

The class I small leucine-rich proteoglycan biglycan is a crucial structural extracellular matrix component that interacts with a wide range of extracellular matrix molecules. In addition, biglycan is involved in sequestering growth factors such as transforming growth factor-ß and bone morphogenetic proteins and thereby regulating pathway activity. Biglycan consists of a 42-kDa core protein linked to two glycosaminoglycan side chains and both are involved in protein interactions. Biglycan is encoded by the BGN gene located on the X-chromosome and is expressed in various tissues, including vascular tissue, skin, brain, kidney, lung, the immune system, and the musculoskeletal system. Although an increasing amount of data on the biological function of biglycan in the vasculature has been produced, its role in thoracic aortic aneurysms is still not fully elucidated. This review focuses on the role of biglycan in the healthy thoracic aorta and the development of thoracic aortic aneurysm and dissections in both mice and humans.

The lncRNA SEMA3B-AS1/HMGB1/FBXW7 Axis Mediates the Peritoneal Metastasis of Gastric Cancer by Regulating BGN Protein Ubiquitination.

Peritoneal metastasis (PM) is one of the main causes of a poor prognosis in patients with advanced gastric cancer (GC). lncRNAs have been confirmed to play a very crucial role in the occurrence, development, and metastasis of many human cancers, including gastric cancer. However, the mechanism of lncRNA in PM of GC is rarely studied. We explored the mechanism of PM of GC through lncRNA gene sequencing and protein profiling analysis to detect PM-associated lncRNAs and proteins. A quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to identify the mRNA expression of SEMA3B-AS1 and BGN in GC tissues and adjacent normal tissues. The biological function of SEMA3B-AS1 in the PM of GC was identified through gain- and loss-of-function assays. Chromatin isolation by RNA purification (ChIRP), RNA immunoprecipitation (RIP), RNA pull-down, luciferase reporter, and coimmunoprecipitation (co-IP) assays was carried out to demonstrate the potential mechanism between SEMA3B-AS1 and its downstream genes, including HMGB1, FBXW7, and BGN. Finally, the biological function of SEMA3B-AS1 was demonstrated in animal experiments. The mRNA expression level of SEMA3B-AS1 was downregulated in GC and PM tissues compared to normal stomach tissues; however, BGN was highly expressed at the mRNA level. SEMA3B-AS1 was closely related to PM and the overall survival (OS) of GC patients. Functionally, the overexpression of SEMA3B-AS1 was related to GC progression, PM, and prognosis. Mechanistically, SEMA3B-AS1 could combine with HMGB1 to regulate the transcription of FBXW7, thus facilitating the ubiquitination of BGN. In conclusion, our study demonstrated that the SEMA3B-AS1/HMGB1/FBXW7 axis plays an inhibitory role in the PM of GC by regulating BGN protein ubiquitination. It also provides a new biological marker for the diagnosis and treatment of the PM of GC.

Expression and prognostic analysis of BGN in head and neck squamous cell carcinoma.

OBJECTIVE: BGN belongs to class of small leucine rich proteoglycans, which is high expression in plenty of human cancers. However, the detailed role of BGN remains unclear in Head and neck squamous cell carcinoma (HNSC). MATERIALS AND METHODS: In this study, we assessed the transcriptional expression, protein expression, prognosis, co-expressed genes, functional enrichment, and hub genes in HNSC patients based on the data published in the following databases: ONCOMINE, GEPIA, GEO, LinkedOmics, and HPA databases. Data from the TCGA database was used to analyze the correlations between BGN expression and different clinicopathological features, as well as prognostic analysis. RESULTS: We found that the expression of BGN is higher in patients with HNSC than in control tissues. Pathologically, high BGN expression was significantly correlated with T3 and T4 stage. Besides, high expression of BGN is a poor prognostic factor for overall surviva, not disease free survival. The co-expression genes associated with BGN expression exhibited enriched in various function and pathway, such as extracellular matrix, mitochondrion, PI3K-Akt signaling pathway. A total of 10 hub genes were identified from the co-expressed genes, within which five genes, including FSTL1, LAMB1, SDC2, VCAN, and IGFBP7, were significantly increased in patient's with HNSC. BGN exhibited weak correlations with tumor-infiltrating CD4+ T, macrophages cell, and dendritic cells. Futhermore, many markers of infiltrating immune cells, such as Treg, showed different BGN-related immune infiltration patterns. BGN expression showed strong correlations with diverse immune marker sets in COAD and STAD. CONCLUSIONS: Our results demonstrated that BGN is high expression in HNSC and is a poor prognostic factor for clinical outcome in patients with HNSC. It could serve as a potential prognostic biomarker for patients survival in HNSC.

Mechanical Response of Mouse Cervices Lacking Decorin and Biglycan During Pregnancy.

Cervical remodeling is critical for a healthy pregnancy. The proper regulation of extracellular matrix (ECM) turnover leads to remodeling throughout gestation, transforming the tissue from a stiff material to a compliant, extensible, viscoelastic tissue prepared for delivery. Small leucine-rich proteoglycans (SLRPs) regulate structural fiber assembly in the cervical ECM and overall tissue material properties. To quantify the SLRPs' mechanical role in the cervix, whole cervix specimens from nonpregnant and late pregnant knockout mice of SLRPs, decorin and biglycan, were subjected to cyclic load-unload, ramp-hold, and load-to-failure mechanical tests. Further, a fiber composite material model, accounting for collagen fiber bundle waviness, was developed to describe the cervix's three-dimensional large deformation equilibrium behavior. In nonpregnant tissue, SLRP knockout cervices have the same equilibrium material properties as wild-type tissue. In contrast, the load-to-failure and ramp-hold tests reveal SLRPs impact rupture and time-dependent relaxation behavior. Loss of decorin in nonpregnant (NP) cervices results in inferior rupture properties. After extensive remodeling, cervical strength is similar between all genotypes, but the SLRP-deficient tissue has a diminished ability to dissipate stress during a ramp-hold. In mice with a combined loss of decorin and biglycan, the pregnant cervix loses its extensibility, compliance, and viscoelasticity. These results suggest that decorin and biglycan are necessary for crucial extensibility and viscoelastic material properties of a healthy, remodeled pregnant cervix.

Novel antiangiogenic therapy targeting biglycan using tumor endothelial cell-specific liposomal siRNA delivery system.

Tumor blood vessels play important roles in tumor progression and metastasis. Targeting tumor endothelial cells (TECs) is one of the strategies for cancer therapy. We previously reported that biglycan, a small leucine-rich proteoglycan, is highly expressed in TECs. TECs utilize biglycan in an autocrine manner for migration and angiogenesis. Furthermore, TEC-derived biglycan stimulates tumor cell migration in a paracrine manner leading to tumor cell intravasation and metastasis. In this study, we explored the therapeutic effect of biglycan inhibition in the TECs of renal cell carcinoma using an in vivo siRNA delivery system known as a multifunctional envelope-type nanodevice (MEND), which contains a unique pH-sensitive cationic lipid. To specifically deliver MEND into TECs, we incorporated cyclo(Arg-Gly-Asp-D-Phe-Lys) (cRGD) into MEND because αV ß3 integrin, a receptor for cRGD, is selective and highly expressed in TECs. We developed RGD-MEND-encapsulating siRNA against biglycan. First, we confirmed that MEND was delivered into OS-RC-2 tumor-derived TECs and induced in vitro RNAi-mediated gene silencing. MEND was then injected intravenously into OS-RC-2 tumor-bearing mice. Flow cytometry analysis demonstrated that MEND was specifically delivered into TECs. Quantitative RT-PCR indicated that biglycan was knocked down by biglycan siRNA-containing MEND. Finally, we analyzed the therapeutic effect of biglycan silencing by MEND in TECs. Tumor growth was inhibited by biglycan siRNA-containing MEND. Tumor microenvironmental factors such as fibrosis were also normalized using biglycan inhibition in TECs. Biglycan in TECs can be a novel target for cancer treatment.

Aberrant expression of the extracellular matrix component Biglycan regulated by Hedgehog signalling promotes colorectal cancer cell proliferation.

Hedgehog (Hh) signalling plays essential roles in regulating embryonic development and contributes to tumour initiation, growth and progression in multiple cancers. The detailed mechanism by which Hh signalling participates in tumour growth warrants thorough study, although several downstream target genes have been identified. Herein, a set of novel targets of Hh signalling was identified in multiple types of tumour cells via RNA-Seq analysis. Among these targets, the expression regulation and oncogenic function of the extracellular matrix component biglycan (BGN) were investigated. Further investigation verified that Hh signalling activates the expression of BGN via the transcription factor Gli2, which directly binds to the promoter region of BGN. Functional assays revealed that BGN facilitates tumour cell growth and proliferation in colorectal cancer (CRC) cells, and xenograft assays confirmed that BGN also promotes tumour growth . Moreover, analysis of clinical CRC samples showed that both the protein and mRNA levels of BGN are increased in CRC tissues compared to those in adjacent tissues, and higher expression of BGN is correlated with poorer prognosis of CRC patients, further confirming the function of BGN in CRC. Taken together, aberrantly activated Hh signalling increases the expression of BGN, possibly regulates the extracellular matrix, and thereby promotes tumour growth in CRC.