Testican-1: A Differentially Expressed Proteoglycan with Protease Inhibiting Activities

Roles of SPOCK1 in the Formation Mechanisms and Treatment of Non-Small-Cell Lung Cancer and Brain Metastases from Lung Cancer

Lung cancer is a malignant tumor with high morbidity and mortality in China and worldwide. Once it metastasizes to the brain, its prognosis is very poor. Brain metastases are found in about 20% of newly diagnosed non-small-cell lung cancer (NSCLC) patients. About 30% of NSCLC patients develop brain metastases during treatment. NSCLC that is positive for EGFR, ALK, and ROS1 variations is especially likely to metastasize to the brain. SPOCK1 is a proteoglycan with systemic physiological functions. It regulates the self-renewal of brain metastasis-initiating cells, regulates invasion and metastasis from the lung to the brain, plays an important role in tumor progression and treatment resistance, and has higher expression in metastatic tumor tissues than other tissues. Current treatments for NSCLC brain metastases include surgery, whole-brain radiotherapy, stereotactic radiotherapy, targeted therapy, and chemotherapy. SPOCK1 is involved in many signaling pathways, by which it influences a variety of NSCLC treatment methods. In this paper, the progress of research on the treatment of NSCLC brain metastases is reviewed to guide decisions on treatment options in clinical practice.

Protein glycosylation in cardiovascular health and disease

Protein glycosylation, which involves the attachment of carbohydrates to proteins, is one of the most abundant protein co-translational and post-translational modifications. Advances in technology have substantially increased our knowledge of the biosynthetic pathways involved in protein glycosylation, as well as how changes in glycosylation can affect cell function. In addition, our understanding of the role of protein glycosylation in disease processes is growing, particularly in the context of immune system function, infectious diseases, neurodegeneration and cancer. Several decades ago, cell surface glycoproteins were found to have an important role in regulating ion transport across the cardiac sarcolemma. However, with very few exceptions, our understanding of how changes in protein glycosylation influence cardiovascular (patho)physiology remains remarkably limited. Therefore, in this Review, we aim to provide an overview of N-linked and O-linked protein glycosylation, including intracellular O-linked N-acetylglucosamine protein modification. We discuss our current understanding of how all forms of protein glycosylation contribute to normal cardiovascular function and their roles in cardiovascular disease. Finally, we highlight potential gaps in our knowledge about the effects of protein glycosylation on the heart and vascular system, highlighting areas for future research.

CNS/PNS proteoglycans functionalize neuronal and astrocyte niche microenvironments optimizing cellular activity by preserving membrane polarization dynamics, ionic microenvironments, ion fluxes, neuronal activation, and network neurotransductive capacity

Central and peripheral nervous system (CNS/PNS) proteoglycans (PGs) have diverse functional roles, this study examined how these control cellular behavior and tissue function. The CNS/PNS extracellular matrix (ECM) is a dynamic, responsive, highly interactive, space-filling, cell supportive, stabilizing structure maintaining tissue compartments, ionic microenvironments, and microgradients that regulate neuronal activity and maintain the neuron in an optimal ionic microenvironment. The CNS/PNS contains a high glycosaminoglycan content (60% hyaluronan, HA) and a diverse range of stabilizing PGs. Immobilization of HA in brain tissues by HA interactive hyalectan PGs preserves tissue hydration and neuronal activity, a paucity of HA in brain tissues results in a pro-convulsant epileptic phenotype. Diverse CS, KS, and HSPGs stabilize the blood-brain barrier and neurovascular unit, provide smart gel neurotransmitter neuron vesicle storage and delivery, organize the neuromuscular junction basement membrane, and provide motor neuron synaptic plasticity, and photoreceptor and neuron synaptic functions. PG-HA networks maintain ionic fluxes and microgradients and tissue compartments that contribute to membrane polarization dynamics essential to neuronal activation and neurotransduction. Hyalectans form neuroprotective perineuronal nets contributing to synaptic plasticity, memory, and cognitive learning. Sialoglycoprotein associated with cones and rods (SPACRCAN), an HA binding CSPG, stabilizes the inter-photoreceptor ECM. HSPGs pikachurin and eyes shut stabilize the photoreceptor synapse aiding in phototransduction and neurotransduction with retinal bipolar neurons crucial to visual acuity. This is achieved through Laminin G motifs in pikachurin, eyes shut, and neurexins that interact with the dystroglycan-cytoskeleton-ECM-stabilizing synaptic interconnections, neuronal interactive specificity, and co-ordination of regulatory action potentials in neural networks.

The secreted neuronal signal Spock1 promotes blood-brain barrier development

The blood-brain barrier (BBB) is a unique set of properties of the brain vasculature which severely restrict its permeability to proteins and small molecules. Classic chick-quail chimera studies have shown that these properties are not intrinsic to the brain vasculature but rather are induced by surrounding neural tissue. Here, we identify Spock1 as a candidate neuronal signal for regulating BBB permeability in zebrafish and mice. Mosaic genetic analysis shows that neuronally expressed Spock1 is cell non-autonomously required for a functional BBB. Leakage in spock1 mutants is associated with altered extracellular matrix (ECM), increased endothelial transcytosis, and altered pericyte-endothelial interactions. Furthermore, a single dose of recombinant SPOCK1 partially restores BBB function in spock1 mutants by quenching gelatinase activity and restoring vascular expression of BBB genes including mcamb. These analyses support a model in which neuronally secreted Spock1 initiates BBB properties by altering the ECM, thereby regulating pericyte-endothelial interactions and downstream vascular gene expression.

Mechanism of prognostic marker SPOCK3 affecting malignant progression of prostate cancer and construction of prognostic model

BACKGROUND

SPOCK3 is a secreted extracellular matrix proteoglycan. This study aimed to investigate the effect of SPOCK3 on the malignant progression of prostate cancer and to construct a prognostic model to predict DFS of patients with prostate cancer.

METHODS

Clinical and transcriptome sequencing data for prostate cancer were download from the TCGA and GEO databases. The survival curve showed that SPOCK3 has prognostic significance. GO, KEGG, and GSEA enrichment analysis were used to investigate how SPOCK3 affects the malignant progression of prostate cancer. Based on ESTIMATE and ssGSEA, the relationship between SPOCK3 and immune cell infiltration in prostate cancer tissue was clarified. Univariate and multivariate COX regression analysis was used to identify the independent prognostic factors of prostate cancer OS and to construct a nomogram. The calibration curve and ROC curves were drawn to assess the nomogram's predictive power.

RESULTS

The survival curve revealed that patients in the low-expression group of SPOCK3 had a poor prognosis. According to enrichment analysis, SOPCK3-related genes were enriched in collagen-containing extracellular matrix, PI3K-Akt, and MAPK signaling pathway. ESTIMATE analysis revealed that SPOCK3 expression was positively correlated with the interstitial score, immune score, and ESTIMATE score. The results of ssGSEA analysis revealed that the infiltration levels of Mast cells, NK cells, and B cells were higher in the SPOCK3 high expression group. Cox regression analysis showed that SPOCK3 expression level, T and Gleason score were independent risk factors of patient prognosis, and a nomogram was constructed. The ROC curve showed the AUCs of DFS at 2, 3, and 5 years.

CONCLUSION

SPOCK3 is a protective factor for DFS in prostate cancer patients. SPOCK3 is significantly associated with immune cell infiltration. The prognostic model constructed based on SPOCK3 has excellent predictive performance.

SPOCK1 Overexpression Suggests Poor Prognosis of Ovarian Cancer

Purpose: Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1) has been found in a variety of malignant tumors and is associated with a poor prognosis. We aimed to explore the role of SPOCK1 in ovarian cancer. Methods: Ovarian cancer cell lines SKOV3 and SW626 were transfected with SPOCK1 overexpressing or empty vector using electroporation. Cells were studied by immunostaining and an automated Western blotting system. BrdU uptake and wound healing assays assessed cell proliferation and migration. SPOCK1 expression in human ovarian cancer tissues and in blood samples were studied by immunostaining and ELISA. Survival of patients with tumors exhibiting low and high SPOCK1 expression was analyzed using online tools. Results: Both transfected cell lines synthesized different SPOCK1 variants; SKOV3 cells also secreted the proteoglycan. SPOCK1 overexpression stimulated DNA synthesis and cell migration involving p21CIP1. Ovarian cancer patients had increased SPOCK1 serum levels compared to healthy controls. Tumor cells of tissues also displayed abundant SPOCK1. Moreover, SPOCK1 levels were higher in untreated ovarian cancer serum and tissue samples and lower in recipients of chemotherapy. According to in silico analyses, high SPOCK1 expression was correlated with shorter survival. Conclusion: Our findings suggest SPOCK1 may be a viable anti-tumor therapeutic target and could be used for monitoring ovarian cancer.

SPOCK1 with unexpected function. The start of a new career

SPOCK1, 2 and 3 are considered as matricellular proteoglycans without structural role. Their functions are only partly elucidated. SPOCK1 was detected in the brain as a member of the neural synapses, then in the neuromuscular junctions. It plays a role in the regulation of blood-brain barrier. Its best characterized activity was its oncogenic potential discovered in 2012. Its deleterious effect on tumor progression was detected on 36 different types of tumors by the end of 2020. However, its mode of actions is still not completely understood. Furthermore, even less was discovered about its physiological function. The fact that it was found to localize in the mitochondria and interfered with the lipid metabolism indicated, that the full discovery of SPOCK1 still waiting for us.

LncRNA THEMIS2-211, a tumor-originated circulating exosomal biomarker, promotes the growth and metastasis of hepatocellular carcinoma by functioning as a competing endogenous RNA

Hepatocellular carcinoma (HCC) is a major challenge for human health. Finding reliable diagnostic biomarkers and therapeutic targets for HCC is highly desired in the clinic. Currently, circulating exosomal lncRNA is a promising biomarker for the diagnosis of cancer and lncRNA is also a potential target in cancer therapy. Here, the diagnostic value of a panel based on exosomal lncRNA THEMIS2-211 and PRKACA-202, superior to that of AFP, was identified for diagnosing human HCC. Besides, the performance of exosomal lncRNA THEMIS2-211 alone exceeds that of AFP in diagnosing early-stage HCC patients (stage I). Furthermore, lncRNA THEMIS2-211 is highly expressed in HCC tissues and correlated with the poor prognosis of HCC patients. LncRNA THEMIS2-211 is upregulated and localized in the cytoplasm of HCC cells. LncRNA THEMIS2-211 exerts its biological function as an oncogene that promotes the proliferation, migration, invasion, EMT of HCC cells by physically interacting with miR-940 and therefore promoting SPOCK1 expressions. Rescue assays show the regulation of SPOCK1 by lncRNA THEMIS2-211 dependents on miR-940. The discovery of lncRNA THEMIS2-211 further illuminates the molecular pathogenesis of HCC and the THEMIS2-211/miR-940/SPOCK1 axis may act as a potential therapeutic target for HCC.

SPOCK1 Promotes the Development of Hepatocellular Carcinoma

The extracellular matrix proteoglycan SPOCK1 is increasingly recognized as a contributor to the development and progression of cancers. Here, we study how SPOCK1, which is present in non-tumorous hepatocytes at low concentrations, promotes the development and progression of malignant hepatocellular tumors. Although SPOCK1 is an extracellular matrix proteoglycan, its concentration increases in the cytoplasm of hepatocytes starting with very low expression in the normal cells and then appearing in much higher quantities in cells of cirrhotic human liver and hepatocellular carcinoma. This observation is similar to that observed after diethylnitrosamine induction of mouse hepatocarcinogenesis. Furthermore, syndecan-1, the major proteoglycan of the liver, and SPOCK1 are in inverse correlation in the course of these events. In hepatoma cell lines, the cytoplasmic SPOCK1 colocalized with mitochondrial markers, such as MitoTracker and TOMM20, a characteristic protein of the outer membrane of the mitochondrion and could be detected in the cell nucleus. SPOCK1 downregulation of hepatoma cell lines by siRNA inhibited cell proliferation, upregulated p21 and p27, and interfered with pAkt and CDK4 expression. A tyrosine kinase array revealed that inhibition of SPOCK1 in the liver cancer cells altered MAPK signaling and downregulated several members of the Sarc family, all related to the aggressivity of the hepatoma cell lines. These studies support the idea that SPOCK1 enhancement in the liver is an active contributor to human and rodent hepatocarcinogenesis and cancer progression. However, its mitochondrial localization raises the possibility that it has a currently unidentified physiological function in normal hepatocytes.

SPOCK1 promotes metastasis in pancreatic cancer via NF-κB-dependent epithelial-mesenchymal transition by interacting with IκB-α

BACKGROUND

Sparc/osteonectin, cwcv and kazal-like domain proteoglycan 1 (SPOCK1) has been reported to function as an oncogene in a variety of cancer types. Increasing evidence suggests that SPOCK1 contributes to the metastatic cascade, including invasion, epithelial-mesenchymal transition (EMT) and micro-metastasis formation. As yet, however, the underlying mechanism is not clearly understood. Here, we evaluated the expression and clinicopathological significance of SPOCK1 in primary pancreatic cancer (PC) specimens and explored the mechanisms underlying SPOCK1-mediated PC cell growth and metastasis.

METHODS

The clinical relevance of SPOCK1 was evaluated in 81 patients with PC. The effect of SPOCK1 on proliferation, cell cycle progression, EMT and metastasis was examined in vitro and in vivo. The molecular mechanisms involved in SPOCK1-mediated regulation of NF-κB-dependent EMT were assessed in PC cell lines.

RESULTS

We found that SPOCK1 expression was increased in PC tissues and was associated with lymph node metastasis. Silencing or exogenous overexpression of SPOCK1 markedly altered the proliferation of PC cells through cell cycle transition. Overexpression of SPOCK1 promoted PC cell migration and invasion by regulating EMT progression. Moreover, we found that SPOCK1 contributes to EMT and metastasis by activating the NF-κB signalling pathway via direct interaction with IκBα. After NF-κB pathway inhibition by BAY11-7082, we found that PC cell motility and EMT induced by SPOCK1 were reversed.

CONCLUSION

From our data we conclude that SPOCK1 promotes PC metastasis via NF-κB-dependent EMT by interacting with IκBα. This newly identified mechanism may provide novel clues for the (targeted) treatment of PC patients.

Neural Tissue Homeostasis and Repair Is Regulated via CS and DS Proteoglycan Motifs

Chondroitin sulfate (CS) is the most abundant and widely distributed glycosaminoglycan (GAG) in the human body. As a component of proteoglycans (PGs) it has numerous roles in matrix stabilization and cellular regulation. This chapter highlights the roles of CS and CS-PGs in the central and peripheral nervous systems (CNS/PNS). CS has specific cell regulatory roles that control tissue function and homeostasis. The CNS/PNS contains a diverse range of CS-PGs which direct the development of embryonic neural axonal networks, and the responses of neural cell populations in mature tissues to traumatic injury. Following brain trauma and spinal cord injury, a stabilizing CS-PG-rich scar tissue is laid down at the defect site to protect neural tissues, which are amongst the softest tissues of the human body. Unfortunately, the CS concentrated in gliotic scars also inhibits neural outgrowth and functional recovery. CS has well known inhibitory properties over neural behavior, and animal models of CNS/PNS injury have demonstrated that selective degradation of CS using chondroitinase improves neuronal functional recovery. CS-PGs are present diffusely in the CNS but also form denser regions of extracellular matrix termed perineuronal nets which surround neurons. Hyaluronan is immobilized in hyalectan CS-PG aggregates in these perineural structures, which provide neural protection, synapse, and neural plasticity, and have roles in memory and cognitive learning. Despite the generally inhibitory cues delivered by CS-A and CS-C, some CS-PGs containing highly charged CS disaccharides (CS-D, CS-E) or dermatan sulfate (DS) disaccharides that promote neural outgrowth and functional recovery. CS/DS thus has varied cell regulatory properties and structural ECM supportive roles in the CNS/PNS depending on the glycoform present and its location in tissue niches and specific cellular contexts. Studies on the fruit fly, Drosophila melanogaster and the nematode Caenorhabditis elegans have provided insightful information on neural interconnectivity and the role of the ECM and its PGs in neural development and in tissue morphogenesis in a whole organism environment.

Mutant Presenilin 1 Dysregulates Exosomal Proteome Cargo Produced by Human-Induced Pluripotent Stem Cell Neurons

The accumulation and propagation of hyperphosphorylated tau (p-Tau) is a neuropathological hallmark occurring with neurodegeneration of Alzheimer's disease (AD). Extracellular vesicles, exosomes, have been shown to initiate tau propagation in the brain. Notably, exosomes from human-induced pluripotent stem cell (iPSC) neurons expressing the AD familial A246E mutant form of presenilin 1 (mPS1) are capable of inducing tau deposits in the mouse brain after in vivo injection. To gain insights into the exosome proteome cargo that participates in propagating tau pathology, this study conducted proteomic analysis of exosomes produced by human iPSC neurons expressing A246E mPS1. Significantly, mPS1 altered the profile of exosome cargo proteins to result in (1) proteins present only in mPS1 exosomes and not in controls, (2) the absence of proteins in the mPS1 exosomes which were present only in controls, and (3) shared proteins which were upregulated or downregulated in the mPS1 exosomes compared to controls. These results show that mPS1 dysregulates the proteome cargo of exosomes to result in the acquisition of proteins involved in the extracellular matrix and protease functions, deletion of proteins involved in RNA and protein translation systems along with proteasome and related functions, combined with the upregulation and downregulation of shared proteins, including the upregulation of amyloid precursor protein. Notably, mPS1 neuron-derived exosomes displayed altered profiles of protein phosphatases and kinases involved in regulating the status of p-tau. The dysregulation of exosome cargo proteins by mPS1 may be associated with the ability of mPS1 neuron-derived exosomes to propagate tau pathology.

The Protective Effects of Protease Inhibitor MG-132 on Sepsis-Induced Acute Kidney Injury and Its Mechanisms

MG-132 is an aldehyde peptide proteasome inhibitor, which reduces the inflammatory response and exerts a protective effect on severe acute pancreatitis and associated lung injury of rats. However, the involvement of MG-132 in sepsis-induced acute kidney injury (AKI) and the underlying mechanisms remain unknow. In this study, SD rats were employed to induce sepsis by cecal ligation and puncture (CLP) method and then divided into control, sham, CLP, and CLP + MG-132. Histopathology observation was detected by hematoxylin and eosin staining. The levels of biomarkers representing renal function such as serum creatinine (Scr), blood urea nitrogen (BUN), serum cystatin C (Scys C), and indicators of AKI such as Kim-1, IL-18, α glutathione S-traferase (α-GST) and albumin were measured by ELISA. Western blot and immunohistochemistry were performed to measure Testican-1. In order to assess the role of Testican-1, the expression of β-catenin, c-myc and cyclinD1 were evaluated by western blot. The results indicated that the levels of SCr, BUN, Scys C, KIM-1, IL-18, GST-α and albumin were decreased after MG-132 treatment compared with CLP group. And both pathological injury and W/D ratio were obviously improved in the CLP + MG- 132 group. Furthermore, the level of Testican-1 increased in the CLP group while a decreased presented in the CLP + MG-132 group. The expression of β-catenin, c-myc and cyclinD1 were downregulated in the CLP + MG-132 group compared to the CLP group. Our findings suggested that MG-132 can protect against AKI via inhibiting Testican-1 through the Wnt/β-catenin pathway MG-132 served as a novel biomarker and therapeutic regimen for sepsis-induced AKI.

SPOCK1 overexpression induced by platelet-derived growth factor-BB promotes hepatic stellate cell activation and liver fibrosis through the integrin α5β1/PI3K/Akt signaling pathway

Sparc/osteonectin, cwcv, and kazal-like domain proteoglycan 1 (SPOCK1) is a matricellular protein which regulates cell proliferation, invasion, and survival but the function of SPOCK1 in liver fibrosis is obscure. In this study, we found that SPOCK1 expression increased significantly in fibrotic liver tissues and activated primary rat hepatic stellate cells (R-HSCs). SPOCK1 co-localized with α-smooth muscle actin (α-SMA) in the cytoplasm. Mechanistically, we found platelet-derived growth factor-BB (PDGF-BB) induced SPOCK1 expression by activating the PI3K/Akt/forkhead box M1 (FoxM1) signaling pathway. Intracellular SPOCK1 downregulation decreased the HSC activation, proliferation, and migration induced by PDGF-BB. Furthermore, intracellular SPOCK1 overexpression or recombinant SPOCK1 treatment promoted HSC activation, proliferation, and migration by activating the PI3K/Akt signaling pathway. Co-immunoprecipitation, double immunofluorescence staining indicated that SPOCK1 interacted with integrin α5β1, and neutralization of integrin α5β1 significantly reduced the role of recombinant SPOCK1 in HSCs. In vivo HSC-specific SPOCK1 knockdown following lentivirus administration dramatically ameliorated thioacetamide (TAA)-induced collagen deposition in rat livers. Collectively, our study indicates that SPOCK1 is crucial for hepatic fibrosis and it might be a promising therapeutic target.

A Genome-Wide Association Study Identifies Genetic Variants Associated with Mathematics Ability

Mathematics ability is a complex cognitive trait with polygenic heritability. Genome-wide association study (GWAS) has been an effective approach to investigate genetic components underlying mathematic ability. Although previous studies reported several candidate genetic variants, none of them exceeded genome-wide significant threshold in general populations. Herein, we performed GWAS in Chinese elementary school students to identify potential genetic variants associated with mathematics ability. The discovery stage included 494 and 504 individuals from two independent cohorts respectively. The replication stage included another cohort of 599 individuals. In total, 28 of 81 candidate SNPs that met validation criteria were further replicated. Combined meta-analysis of three cohorts identified four SNPs (rs1012694, rs11743006, rs17778739 and rs17777541) of SPOCK1 gene showing association with mathematics ability (minimum p value 5.67 × 10⁻¹⁰, maximum β −2.43). The SPOCK1 gene is located on chromosome 5q31.2 and encodes a highly conserved glycoprotein testican-1 which was associated with tumor progression and prognosis as well as neurogenesis. This is the first study to report genome-wide significant association of individual SNPs with mathematics ability in general populations. Our preliminary results further supported the role of SPOCK1 during neurodevelopment. The genetic complexities underlying mathematics ability might contribute to explain the basis of human cognition and intelligence at genetic level.

Amyloid-β Precursor Protein Modulates the Sorting of Testican-1 and Contributes to Its Accumulation in Brain Tissue and Cerebrospinal Fluid from Patients with Alzheimer Disease

The mechanisms leading to amyloid-β (Aβ) accumulation in sporadic Alzheimer disease (AD) are unknown but both increased production or impaired clearance likely contribute to aggregation. To understand the potential roles of the extracellular matrix proteoglycan Testican-1 in the pathophysiology of AD, we used samples from AD patients and controls and an in vitro approach. Protein expression analysis showed increased levels of Testican-1 in frontal and temporal cortex of AD patients; histological analysis showed that Testican-1 accumulates and co-aggregates with Aβ plaques in the frontal, temporal and entorhinal cortices of AD patients. Proteomic analysis identified 10 fragments of Testican-1 in cerebrospinal fluid (CSF) from AD patients. HEK293T cells expressing human wild type or mutant Aβ precursor protein (APP) were transfected with Testican-1. The co-expression of both proteins modified the sorting of Testican-1 into the endocytic pathway leading to its transient accumulation in Golgi, which seemed to affect APP processing, as indicated by reduced Aβ40 and Aβ42 levels in APP mutant cells. In conclusion, patient data reflect a clearance impairment that may favor Aβ accumulation in AD brains and our in vitro model supports the notion that the interaction between APP and Testican-1 may be a key step in the production and aggregation of Aβ species.

SPOCK1 Overexpression Confers a Poor Prognosis in Urothelial Carcinoma

Purpose:The majority deaths of cancer patients are related to metastasis, thus genes associated with cell motility interest us. SPOCK1 was elected by data mining and serial evaluation. In addition, SPOCK1 has been reported to be highly expressed in different human cancers and been related to adverse outcomes. Therefore, we validate its prognostic significance in urothelial carcinoma (UC).

Materials and Methods:Real-time RT-PCR assay was used to detect SPOCK1 transcript level in 27 urinary tract urothelial carcinoma (UTUC) and 27 urinary bladder urothelial carcinoma (UBUC) samples. Immunohistochemistry evaluated by H-score determined SPOCK1 expressions in 340 UTUCs and 295 UBUCs. The transcript and protein expression were correlated with clinicopathological features. Further evaluations of the prognostic significance of SPOCK1 for disease-specific survival (DSS) and metastasis-free survival (MeFS) were analyzed.

Results:The expressions of SPOCK1 in UC were higher than those in normal urothelium by immunohistochemistry. The statistical analysis of clinicopathologic characteristics and immunohistochemistry showed that the higher expression of SPOCK1 was correlated to pT status (P<0.001), lymph node metastasis (UTUC, P=0.006; UBUC, P=0.033), higher histological grade (UTUC, P<0.001; UBUC, P<0.001), vascular invasion (UTUC, P<0.001; UBUC, P<0.001), perineurial invasion (UTUC, P<0.001; UBUC, P=0.001) and frequent mitosis (UTUC, P<0.001; UBUC, P=0.001). The prognosis of SPOCK1 of UC showed high SPOCK1 expression had significantly worse DSS and MeFS.

Conclusions:The investigation demonstrated that the higher expression of SPOCK1 correlates with a poor prognosis in UC.

Characterization of the Transcriptional Complexity of the Receptive and Pre-receptive Endometria of Dairy Goats

Endometrium receptivity is essential for successful embryo implantation in mammals. However, the lack of genetic information remains an obstacle to understanding the mechanisms underlying the development of a receptive endometrium from the pre-receptive phase in dairy goats. In this study, more than 4 billion high-quality reads were generated and de novo assembled into 102,441 unigenes; these unigenes were annotated using published databases. A total of 3,255 unigenes that were differentially expressed (DEGs) between the PE and RE were discovered in this study (P-values < 0.05). In addition, 76,729–77,102 putative SNPs and 12,837 SSRs were discovered in this study. Bioinformatics analysis of the DEGs revealed a number of biological processes and pathways that are potentially involved in the establishment of the RE, notably including the GO terms proteolysis, apoptosis, and cell adhesion and the KEGG pathways Cell cycle and extracellular matrix (ECM)-receptor interaction. We speculated that ADCY8, VCAN, SPOCK1, THBS1, and THBS2 may play important roles in the development of endometrial receptivity. The de novo assembly provided a good starting point and will serve as a valuable resource for further investigations into endometrium receptivity in dairy goats and future studies on the genomes of goats and other related mammals.

Interactions of signaling proteins, growth factors and other proteins with heparan sulfate: mechanisms and mysteries

Heparan sulfate (HS) is a component of cell surface and matrix-associated proteoglycans (HSPGs) that, collectively, play crucial roles in many physiologic processes including cell differentiation, organ morphogenesis and cancer. A key function of HS is to bind and interact with signaling proteins, growth factors, plasma proteins, immune-modulators and other factors. In doing so, the HS chains and HSPGs are able to regulate protein distribution, bio-availability and action on target cells and can also serve as cell surface co-receptors, facilitating ligand-receptor interactions. These proteins contain an HS/heparin-binding domain (HBD) that mediates their association and contacts with HS. HBDs are highly diverse in sequence and predicted structure, contain clusters of basic amino acids (Lys and Arg) and possess an overall net positive charge, most often within a consensus Cardin-Weintraub (CW) motif. Interestingly, other domains and residues are now known to influence protein-HS interactions, as well as interactions with other glycosaminoglycans, such as chondroitin sulfate. In this review, we provide a description and analysis of HBDs in proteins including amphiregulin, fibroblast growth factor family members, heparanase, sclerostin and hedgehog protein family members. We discuss HBD structural and functional features and important roles carried out by other protein domains, and also provide novel conformational insights into the diversity of CW motifs present in Sonic, Indian and Desert hedgehogs. Finally, we review progress in understanding the pathogenesis of a rare pediatric skeletal disorder, Hereditary Multiple Exostoses (HME), characterized by HS deficiency and cartilage tumor formation. Advances in understanding protein-HS interactions will have broad implications for basic biology and translational medicine as well as for the development of HS-based therapeutics.

Carrier of Wingless (Cow), a secreted heparan sulfate proteoglycan, promotes extracellular transport of Wingless

Morphogens are signaling molecules that regulate growth and patterning during development by forming a gradient and activating different target genes at different concentrations. The extracellular distribution of morphogens is tightly regulated, with the Drosophila morphogen Wingless (Wg) relying on Dally-like (Dlp) and transcytosis for its distribution. However, in the absence of Dlp or endocytic activity, Wg can still move across cells along the apical (Ap) surface. We identified a novel secreted heparan sulfate proteoglycan (HSPG) that binds to Wg and promotes its extracellular distribution by increasing Wg mobility, which was thus named Carrier of Wg (Cow). Cow promotes the Ap transport of Wg, independent of Dlp and endocytosis, and this function addresses a previous gap in the understanding of Wg movement. This is the first example of a diffusible HSPG acting as a carrier to promote the extracellular movement of a morphogen.

Testican-1-mediated epithelial-mesenchymal transition signaling confers acquired resistance to lapatinib in HER2-positive gastric cancer

Human epidermal growth factor receptor 2 (HER2)-directed treatment using trastuzumab has shown clinical benefit in HER2-positive gastric cancer. Clinical trials using lapatinib in HER2-positive gastric cancer are also currently underway. As with other molecularly targeted agents, the emergence of acquired resistance to HER2-directed treatment is an imminent therapeutic problem for HER2-positive gastric cancer. In order to investigate the mechanisms of acquired resistance to HER2-directed treatment in gastric cancer, we generated lapatinib-resistant gastric cancer cell lines (SNU216 LR) in vitro by chronic exposure of a HER2-positive gastric cancer cell line (SNU216) to lapatinib. The resultant SNU216 LR cells were also resistant to gefitinib, cetuximab, trastuzumab, afatinib and dacomitinib. Interestingly, SNU216 LR cells displayed an epithelial-mesenchymal transition (EMT) phenotype and maintained the activation of MET, HER3, Stat3, Akt and mitogen-activated protein kinase signaling in the presence of lapatinib. Using gene expression arrays, we identified the upregulation of a variety of EMT-related genes and extracellular matrix molecules, such as Testican-1, in SNU216 LR cells. We showed that the inhibition of Testican-1 by small interfering RNA decreased Testican-1-induced, MET-dependent, downstream signaling, and restored sensitivity to lapatinib in these cells. Furthermore, treatment with XAV939 selectively inhibited β-catenin-mediated transcription and Testican-1-induced EMT signaling, leading to G1 arrest. Taken together, these data support the potential role of EMT in acquired resistance to HER2-directed treatment in HER2-positive gastric cancer, and provide insights into strategies for preventing and/or overcoming this resistance in patients.

Genes responsible for the characteristics of primary cultured invasive phenotype hepatocellular carcinoma cells

The common genes responsible for the characteristics of primary cultured invasive phenotype hepatocellular carcinoma (HCC) cells were investigated. Primary cultured HCC cells from three patients were separated by Matrigel invasion into parent and invasive cells. Whole human genome oligo microarray was applied to detect the differentially expressed genes in invasive cells. A purchased HCC cell line (HA 22T/VGH) was studied for comparison. Forty genes were consistently up-regulated and 14 genes were consistently down-regulated among primary cultured invasive cells. Among these genes, only three up-regulated genes (CNN1, PLAT, SPARC) and one down-regulated tumor suppressor gene (MDFI) had same expressions in invasive cells originated from purchased cell line. For primary cultured invasive cells, differential expressions of several groups of common genes are known to have capacities to promote proliferation (CAV1, IL6, PLAT, RRAD, SRPX), remodeling of extracellular matrix (COL1A1, COL1A2, NID2, TNC, RELN, SPARC), migration (ACTG2, CAV1, CCL2, CCL26, CDC42EP3, CNN1, PHLDB2, PLAT, RRAD, SRPX), implantation (IL6), immune escape (CD70) and angiogenesis (CCL2, IL6, IL18, PLAT, SLIT3). Two genes related to signal transduction (AXL, RASL10B) and one related to metabolism (PTGS2) also showed consistent expressions. Differential expressions of these genes are capable for tumor invasiveness. In conclusion, the characteristics of invasive phenotype HCC cells are originated from differential expressions of several groups of genes rather than few target genes. This information may give us a new insight to design new stratagems in HCC treatment. Analysis of the results from a purchased cell line may have bias due to long-term repeated in vitro cultures.

Iduronic acid in chondroitin/dermatan sulfate: biosynthesis and biological function

The ability of chondroitin/dermatan sulfate (CS/DS) to convey biological information is enriched by the presence of iduronic acid. DS-epimerases 1 and 2 (DS-epi1 and 2), in conjunction with DS-4-O-sulfotransferase 1, are the enzymes responsible for iduronic acid biosynthesis and will be the major focus of this review. CS/DS proteoglycans (CS/DS-PGs) are ubiquitously found in connective tissues, basement membranes, and cell surfaces or are stored intracellularly. Such wide distribution reflects the variety of biological roles in which they are involved, from extracellular matrix organization to regulation of processes such as proliferation, migration, adhesion, and differentiation. They play roles in inflammation, angiogenesis, coagulation, immunity, and wound healing. Such versatility is achieved thanks to their variable composition, both in terms of protein core and the fine structure of the CS/DS chains. Excellent reviews have been published on the collective and individual functions of each CS/DS-PG. This short review presents the biosynthesis and functions of iduronic acid-containing structures, also as revealed by the analysis of the DS-epi1- and 2-deficient mouse models.

Diverse biological functions of the SPARC family of proteins

The SPARC family of proteins represents a diverse group of proteins that modulate cell interaction with the extracellular milieu. The eight members of the SPARC protein family are modular in nature. Each shares a follistatin-like domain and an extracellular calcium binding E-F hand motif. In addition, each family member is secreted into the extracellular space. Some of the shared activities of this family include, regulation of extracellular matrix assembly and deposition, counter-adhesion, effects on extracellular protease activity, and modulation of growth factor/cytokine signaling pathways. Recently, several SPARC family members have been implicated in human disease pathogenesis. This review discusses recent advances in the understanding of the functional roles of the SPARC family of proteins in development and disease.

Gene Expression Profiling of Gastric Cancer

Gastric cancer is the second leading cause of cancer death worldwide, both in men and women. A genomewide gene expression analysis was carried out to identify differentially expressed genes in gastric adenocarcinoma tissues as compared to adjacent normal tissues. We used Agilent's whole human genome oligonucleotide microarray platform representing ~41,000 genes to carry out gene expression analysis. Two-color microarray analysis was employed to directly compare the expression of genes between tumor and normal tissues. Through this approach, we identified several previously known candidate genes along with a number of novel candidate genes in gastric cancer. Testican-1 (SPOCK1) was one of the novel molecules that was 10-fold upregulated in tumors. Using tissue microarrays, we validated the expression of testican-1 by immunohistochemical staining. It was overexpressed in 56% (160/282) of the cases tested. Pathway analysis led to the identification of several networks in which SPOCK1 was among the topmost networks of interacting genes. By gene enrichment analysis, we identified several genes involved in cell adhesion and cell proliferation to be significantly upregulated while those corresponding to metabolic pathways were significantly downregulated. The differentially expressed genes identified in this study are candidate biomarkers for gastric adenoacarcinoma.

Extracellular matrix molecules: potential targets in pharmacotherapy

The extracellular matrix (ECM) consists of numerous macromolecules classified traditionally into collagens, elastin, and microfibrillar proteins, proteoglycans including hyaluronan, and noncollagenous glycoproteins. In addition to being necessary structural components, ECM molecules exhibit important functional roles in the control of key cellular events such as adhesion, migration, proliferation, differentiation, and survival. Any structural inherited or acquired defect and/or metabolic disturbance in the ECM may cause cellular and tissue alterations that can lead to the development or progression of disease. Consequently, ECM molecules are important targets for pharmacotherapy. Specific agents that prevent the excess accumulation of ECM molecules in the vascular system, liver, kidney, skin, and lung; alternatively, agents that inhibit the degradation of the ECM in degenerative diseases such as osteoarthritis would be clinically beneficial. Unfortunately, until recently, the ECM in drug discovery has been largely ignored. However, several of today's drugs that act on various primary targets affect the ECM as a byproduct of the drugs' actions, and this activity may in part be beneficial to the drugs' disease-modifying properties. In the future, agents and compounds targeting directly the ECM will significantly advance the treatment of various human diseases, even those for which efficient therapies are not yet available.

Broad regulation of matrix and adhesion molecules in THP-1 human macrophages by nitroglycerin

Although nitroglycerin (NTG) is effective for the acute relief in coronary ischemic diseases, its long-term benefits in mortality and morbidity have been questioned. The possibility has been raised that NTG may increase the activity of matrix metalloproteinases (MMP), which could lead to disruption and dislodging of atherosclerotic plaques. This study examined the broad effects of acute NTG exposure on the expression and activity of genes encoding MMP-9, as well as an array of ECM and adhesion molecules in THP-1 human macrophages. Gene array studies identified that while NTG exposure (100microM, 48h) did not significantly increase MMP-9 gene expression, genes encoding testican-1, integrin alpha-1, thrombospondin-3, fibronectin-1 and MMP-26 were significantly down-regulated. On the other hand, genes encoding catenin beta-1 and vascular cell-adhesion molecule-1 were up-regulated. Real-time PCR studies confirmed significant down-regulation of testican-1 gene expression, but its protein expression was not significantly altered. NTG exposure, caused a significant increase in total MMP-9 protein expression (1.96-fold) and active MMP-9 (3.7-fold) concentrations. Recombinant MMP-9 was significantly activated by NTG and its dinitrate metabolites, indicating post-translation modification of this protein by organic nitrates. These results indicate that NTG exposure could broadly affect the gene expression and activity of proteases that govern the ECM cascade, thereby potentially altering atherosclerotic plaque stability.

Genome-wide analysis of gene expression in primate taste buds reveals links to diverse processes

Efforts to unravel the mechanisms underlying taste sensation (gustation) have largely focused on rodents. Here we present the first comprehensive characterization of gene expression in primate taste buds. Our findings reveal unique new insights into the biology of taste buds. We generated a taste bud gene expression database using laser capture microdissection (LCM) procured fungiform (FG) and circumvallate (CV) taste buds from primates. We also used LCM to collect the top and bottom portions of CV taste buds. Affymetrix genome wide arrays were used to analyze gene expression in all samples. Known taste receptors are preferentially expressed in the top portion of taste buds. Genes associated with the cell cycle and stem cells are preferentially expressed in the bottom portion of taste buds, suggesting that precursor cells are located there. Several chemokines including CXCL14 and CXCL8 are among the highest expressed genes in taste buds, indicating that immune system related processes are active in taste buds. Several genes expressed specifically in endocrine glands including growth hormone releasing hormone and its receptor are also strongly expressed in taste buds, suggesting a link between metabolism and taste. Cell type-specific expression of transcription factors and signaling molecules involved in cell fate, including KIT, reveals the taste bud as an active site of cell regeneration, differentiation, and development. IKBKAP, a gene mutated in familial dysautonomia, a disease that results in loss of taste buds, is expressed in taste cells that communicate with afferent nerve fibers via synaptic transmission. This database highlights the power of LCM coupled with transcriptional profiling to dissect the molecular composition of normal tissues, represents the most comprehensive molecular analysis of primate taste buds to date, and provides a foundation for further studies in diverse aspects of taste biology.

Downregulation of several fibulin genes in prostate cancer

BACKGROUND

Fibulins, encoded by FBLN genes, are extracellular matrix proteins influencing cell adhesion and migration. Altered expression of fibulins is associated with progression of several cancer types, but has not been studied in prostate cancer.

METHODS

Expression of FBLN1 (major splice forms C and D), FBLN4, FBLN5, SPOCK1, and TENC was compared between 47 prostate cancer samples and 13 benign prostatic tissues by quantitative RT-PCR. Fibulin-1 and fibulin-5 expression was studied by immunohistochemistry. Effects of androgens and the DNA methylation inhibitor 5-aza-2'-deoxycytidine on fibulin expression were investigated in different prostate cancer cell lines.

RESULTS

Our recent microarray analysis suggested downregulation of three fibulins, FBLN1, FBLN4, and FBLN5, in prostate cancer, while two further ECM genes, SPOCK1 (testican) and TENC (tenascin C), appeared upregulated or unchanged. These observations were corroborated by quantitative RT-PCR. Accordingly, FBLN1 and FBLN4 were weakly expressed in carcinoma lines compared to normal prostate epithelial cells (PrECs). Only FBLN4 was induced by 5-aza-2'-deoxycytidine, but its promoter was unmethylated. Androgen did not affect expression of FBLN genes. The FBLN1C and FBLN1D splice forms were coordinately expressed. Fibulin-1 protein was weakly detectable in benign PrECs, but tended to accumulate in cancer cells. Fibulin-5 was predominantly located in the stroma with a strong gradient from the periurethral to the peripheral zone, and lost in cancers.

CONCLUSIONS

Three FBLN genes are significantly downregulated in prostate cancer, whereas SPOCK1 is often upregulated. FBLN5 downregulation fits its postulated anticancerous function, whereas FBLN1 and FBLN4 behave different than in certain other cancers.

Comparative analysis of human conjunctival and corneal epithelial gene expression with oligonucleotide microarrays

PURPOSE

To determine global mRNA expression levels in corneal and conjunctival epithelia and identify transcripts that exhibit preferential tissue expression.

METHODS

cDNA samples derived from human conjunctival and corneal epithelia were hybridized in three independent experiments to a commercial oligonucleotide array representing more than 22,000 transcripts. The resultant signal intensities and microarray software transcript present/absent calls were used in conjunction with the local pooled error (LPE) statistical method to identify transcripts that are preferentially or exclusively expressed in one of the two tissues at significant levels (expression >1% of the beta-actin level). EASE (Expression Analysis Systematic Explorer software) was used to identify biological systems comparatively overrepresented in either epithelium. Immuno-, and cytohistochemistry was performed to validate or expand on selected results of interest.

RESULTS

The analysis identified 332 preferential and 93 exclusive significant corneal epithelial transcripts. The corresponding numbers of conjunctival epithelium transcripts were 592 and 211, respectively. The overrepresented biological processes in the cornea were related to cell adhesion and oxiredox equilibria and cytoprotection activities. In the conjunctiva, the biological processes that were most prominent were related to innate immunity and melanogenesis. Immunohistochemistry for antigen-presenting cells and melanocytes was consistent with these gene signatures. The transcript comparison identified a substantial number of genes that have either not been identified previously or are not known to be highly expressed in these two epithelia, including testican-1, ECM1, formin, CRTAC1, and NQO1 in the cornea and, in the conjunctiva, sPLA(2)-IIA, lipocalin 2, IGFBP3, multiple MCH class II proteins, and the Na-Pi cotransporter type IIb.

CONCLUSIONS

Comparative gene expression profiling leads to the identification of many biological processes and previously unknown genes that are potentially active in the function of corneal and conjunctival epithelia.

Identification of genes differentially expressed in glioblastoma versus pilocytic astrocytoma using Suppression Subtractive Hybridization

Glioblastoma (GBM) is a highly malignant glioma, which has the propensity to infiltrate throughout the brain in contrast to pilocytic astrocytoma (PA) of the posterior fossa, which does not spread and can be cured by surgery. We have used Suppression Subtractive Hybridization to define markers that better delineate the molecular basis of brain invasion and distinguish these tumor groups. We have identified 106 genes expressed in PA versus GBM and 80 genes expressed in GBM versus PA. Subsequent analysis identified a subset of 20 transcripts showing a common differential expression pattern for the two groups. GBM differs from PA by the expression of five genes involved in invasion and angiogenesis: fibronectin, osteopontin, chitinase-3-like-1 (YKL-40), keratoepithelin and fibromodulin. PA differs from GBM by the expression of genes related to metabolism (apolipoprotein D), proteolysis (protease-serine-11), receptor and signal transduction (PLEKHB1 for Pleckstrin-Homology-domain-containing-protein-family-B-member-1), transcription/translation (eukaryotic-translation-elongation-factor-1-alpha1) processes and cell adhesion (SPOCK1 for SPARC/Osteonectin-CWCV-kazal-like-domains-proteoglycan). The expression of these genes was confirmed by real-time quantitative RT-PCR and immunohistochemistry. This study highlights the crucial role of brain invasion in GBM and identifies specific molecules involved in this process. In addition, it offers a restricted list of markers that accurately distinguish PA from GBM.

Testican-1 is dispensable for mouse development

Testicans are proteoglycans belonging to the BM-40/SPARC/osteonectin family of extracellular calcium-binding proteins. Testican-1 is strongly expressed in the brain and has been reported to modulate neuronal attachment and matrix metalloproteinase activation. Characterization of the mouse testican-1 gene (Ticn1), consisting of 12 exons out of which exon 3 is alternatively spliced, allowed the construction of a gene targeting construct. Mice deficient in testican-1 showed no obvious morphological or behavioral abnormalities, were fertile, and had normal life spans. Despite the fact that neither of the testican-1 homologues expressed in the brain, testican-2, testican-3 and SC1/hevin, showed an increased expression in Ticn1 null mice, these results, together with those from other gene targetings, indicate extensive functional redundancy among brain proteoglycans.

Posttranscriptional regulation of the immediate-early gene EGR1 by light in the mouse retina

Synaptic plasticity is modulated by differential regulation of transcription factors such as EGR1 which binds to DNA via a zinc finger binding domain. Inactivation of EGR1 has implicated this gene as a key regulator of memory formation and learning. However, it remains puzzling how synaptic input can lead to an up-regulation of the EGR-1 protein within only a few minutes. Here, we show by immunohistochemical staining that the EGR-1 protein is localized in synapses throughout the mouse retina. We demonstrate for the first time that two variants of Egr-1 mRNA are produced in the retina by alternative polyadenylation, with the longer version having an additional 293 base pairs at the end of the 3'UTR. Remarkably, the use of the alternative polyadenylation site is controlled by light. The additional 3'UTR sequence of the longer variant displays an even higher level of phylogenetic conservation than the coding region of this highly conserved gene. Additionally, it harbours a cytoplasmic polyadenylation element which is known to respond to NMDA receptor activation. The longer version of the Egr-1 mRNA could therefore rapidly respond to excitatory stimuli such as light or glutamate release whereas the short variant, which is predominantly expressed and contains the full coding sequence, lacks the regulatory elements for cytoplasmic polyadenylation in its 3'UTR.

Biosynthesis and alternate targeting of the lysosomal cysteine protease cathepsin L

Upregulation of cathepsin L expression, whether during development or cell transformation, or mediated by ectopic expression from a plasmid, alters the targeting of the protease and thus its physiological function. Upregulated procathepsin L is targeted to small dense core vesicles and to the dense cores of multivesicular bodies, as well as to lysosomes and to the plasma membrane for selective secretion. The multivesicular vesicles resemble secretory lysosomes characterized in specialized cell types in that they are endosomes that stably store an upregulated protein and they possess the tetraspanin CD63. Morphologically the multivesicular endosomes also resemble late endosomes, but they store procathepsin L, not the active protease, and they are not the major site for LAMP-1 accumulation. Distinction between the lysosomal proenzyme and active protease thus identifies two populations of multivesicular endosomes in fibroblasts, one a storage compartment and one an enzymatically active compartment. A distinctive targeting pathway using aggregation is utilized to enrich the storage endosomes with a particular lysosomal protease that can potentially activate and be secreted.