Ovarian carcinomas: CCN genes are aberrantly expressed and CCN1 promotes proliferation of these cells

CYR61 confers chemoresistance by upregulating survivin expression in triple-negative breast cancer

Cysteine-rich angiogenic inducer 61 (CYR61) is a protein from the CCN family of matricellular proteins that play diverse regulatory roles in the extracellular matrix. CYR61 is involved in cell adhesion, migration, proliferation, differentiation, apoptosis, and senescence. Here, we show that CYR61 induces chemoresistance in triple-negative breast cancer (TNBC). We observed that CYR61 is overexpressed in TNBC patients, and CYR61 expression correlates negatively with the survival of patients who receive chemotherapy. CYR61 knockdown reduced cell migration, sphere formation and the cancer stem cell (CSC) population and increased the chemosensitivity of TNBC cells. Mechanistically, CYR61 activated Wnt/β-catenin signaling and increased survivin expression, which are associated with chemoresistance, the epithelial-mesenchymal transition, and CSC-like phenotypes. Altogether, our study demonstrates a novel function of CYR61 in chemotherapy resistance in breast cancer.

Chemotherapy-initiated cysteine-rich protein 61 decreases acute B-lymphoblastic leukemia chemosensitivity

PURPOSE

Chemoresistance is a major challenge for acute lymphoblastic leukemia (ALL) treatment. Cysteine-rich protein 61 (Cyr61) plays an important role in drug resistance modulation of tumor cells, and Cyr61 levels are increased in the bone marrow of patients with ALL and contribute to ALL cell survival. However, the effect of Cyr61 on B cell acute lymphoblastic leukemia (B-ALL) cell chemosensitivity and the regulatory mechanisms underlying Cyr61 production in bone marrow remain unknown.

METHODS

Nalm-6 and Reh human B-ALL cell lines were used in this study. Cyr61 levels were assessed using quantitative real-time PCR (qRT-PCR), western blot analysis, and enzyme-linked immunosorbent assay. The effect of Cyr61 on B-ALL cell chemosensitivity to daunorubicin (DNR) was evaluated using cell viability and flow cytometry analyses. The regulatory mechanisms of Cyr61 production in bone marrow were examined using qRT-PCR and western blot analysis.

RESULTS

Cyr61 knockdown and overexpression increased and decreased the chemosensitivity of B-ALL cells to DNR, respectively. Cyr61 attenuated chemotherapeutic drug-induced apoptosis by upregulating B cell lymphoma-2. Notably, DNR induced DNA damage response and increased Cyr61 secretion in B-ALL cells through the ataxia telangiectasia mutated (ATM)-dependent nuclear factor kappa B pathway.

CONCLUSION

DNR induces Cyr61 production in B-ALL cells, and increased Cyr61 levels reduce the chemosensitivity of B-ALL cells. Consequently, targeting Cyr61 or related ATM signaling pathway may present a promising treatment strategy to enhance the chemosensitivity of patients with B-ALL.

Single-Cell Dissection of the Multiomic Landscape of High-Grade Serous Ovarian Cancer

High-grade serous cancer (HGSC) is the most common subtype of ovarian cancer. HGSC is highly aggressive with poor patient outcomes, and a deeper understanding of HGSC tumorigenesis could help guide future treatment development. To systematically characterize the underlying pathologic mechanisms and intratumoral heterogeneity in human HGSC, we used an optimized single-cell multiomics sequencing technology to simultaneously analyze somatic copy-number alterations (SCNA), DNA methylation, chromatin accessibility, and transcriptome in individual cancer cells. Genes associated with interferon signaling, metallothioneins, and metabolism were commonly upregulated in ovarian cancer cells. Integrated multiomics analyses revealed that upregulation of interferon signaling and metallothioneins was influenced by both demethylation of their promoters and hypomethylation of satellites and LINE1, and potential key transcription factors regulating glycolysis using chromatin accessibility data were uncovered. In addition, gene expression and DNA methylation displayed similar patterns in matched primary and abdominal metastatic tumor cells of the same genetic lineage, suggesting that metastatic cells potentially preexist in the subclones of primary tumors. Finally, the lineages of cancer cells with higher residual DNA methylation levels and upregulated expression of CCN1 and HSP90AA1 presented greater metastatic potential. This study characterizes the critical genetic, epigenetic, and transcriptomic features and their mutual regulatory relationships in ovarian cancer, providing valuable resources for identifying new molecular mechanisms and potential therapeutic targets for HGSC.

SIGNIFICANCE

Integrated analysis of multiomic changes and epigenetic regulation in high-grade serous ovarian cancer provides insights into the molecular characteristics of this disease, which could help improve diagnosis and treatment.

Regulation of CyR61 expression and release by 3-mercaptopyruvate sulfurtransferase in colon cancer cells

Cysteine-rich angiogenic inducer 61 (CYR61, also termed CCN family member 1 or CCN1), is a matricellular protein encoded by the CYR61 gene. This protein has been implicated in the regulation of various cancer-associated processes including tumor growth, angiogenesis, tumor cell adhesion, migration, and invasion as well as the regulation of anticancer drug resistance. Hydrogen sulfide (H₂S) is a gaseous endogenous biological mediator, involved in the regulation of cellular bioenergetics, angiogenesis, invasion, and chemotherapeutic resistance in several types of cancer. H₂S is produced by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST). The current studies were set up to investigate if CBS or 3-MST regulates CyR61 in colon cancer cells in the context of the regulation of proliferation, migration, and survival. The study mainly utilized HCT116 cells, in which two of the principal H₂S-producing enzymes, CBS and 3-MST, are highly expressed. The H₂S donor GYY4137 and the polysulfide donor Na₂S₃ activated the CyR61 promoter in a concentration-dependent fashion. Aminooxyacetic acid (AOAA), a pharmacological inhibitor of CBS as well as HMPSNE: 2-[(4-hydroxy-6- methylpyrimidin-2-yl)sulfanyl]-1-(naphthalen-1-yl)ethan-1-one, a pharmacological inhibitor of 3-MST inhibited CyR61 mRNA expression. This effect was more pronounced in response to HMPSNE than to AOAA and occurred through the modulation of S1PR via ATF1 and CREB. CyR61 was found to play an active, but relatively minor role in maintaining colon cell proliferation. HMPSNE markedly suppressed the secretion/release of CyR61 from the colon cancer cells. Moreover, HMPSNE promoted colon cancer cell apoptosis; endogenously produced CyR61 was found to counteract this effect, at least in part via RhoA activation. Taken together, we conclude that the upregulation of 3-MST in cancer cells exerts cytoprotective effects and confers the cancer cells a more aggressive phenotype - at least in part via the modulation of CyR61 expression and release.

The multifaceted role of Matricellular Proteins in health and cancer, as biomarkers and therapeutic targets

The extracellular matrix (ECM) is composed of a mesh of proteins, proteoglycans, growth factors, and other secretory components. It constitutes the tumor microenvironment along with the endothelial cells, cancer-associated fibroblasts, adipocytes, and immune cells. The proteins of ECM can be functionally classified as adhesive proteins and matricellular proteins (MCP). In the tumor milieu, the ECM plays a major role in tumorigenesis and therapeutic resistance. The current review encompasses thrombospondins, osteonectin, osteopontin, tenascin C, periostin, the CCN family, laminin, biglycan, decorin, mimecan, and galectins. The matrix metalloproteinases (MMPs) are also discussed as they are an integral part of the ECM with versatile functions in the tumor stroma. In this review, the role of these proteins in tumor initiation, growth, invasion and metastasis have been highlighted, with emphasis on their contribution to tumor therapeutic resistance. Further, their potential as biomarkers and therapeutic targets based on existing evidence are discussed. Owing to the recent advancements in protein targeting, the possibility of agents to modulate MCPs in cancer as therapeutic options are discussed.

Binding of the angiogenic/senescence inducer CCN1/CYR61 to integrin α6β1 drives endocrine resistance in breast cancer cells

CCN1/CYR61 promotes angiogenesis, tumor growth and chemoresistance by binding to its integrin receptor α_vβ₃ in endothelial and breast cancer (BC) cells. CCN1 controls also tissue regeneration by engaging its integrin receptor α₆β₁ to induce fibroblast senescence. Here, we explored if the ability of CCN1 to drive an endocrine resistance phenotype in estrogen receptor-positive BC cells relies on interactions with either α_vβ₃ or α₆β₁. First, we took advantage of site-specific mutagenesis abolishing the CCN1 receptor-binding sites to α_vβ₃ and α₆β₁ to determine the integrin partner responsible for CCN1-driven endocrine resistance. Second, we explored a putative nuclear role of CCN1 in regulating ERα-driven transcriptional responses. Retroviral forced expression of a CCN1 derivative with a single amino acid change (D125A) that abrogates binding to α_vβ₃ partially phenocopied the endocrine resistance phenotype induced upon overexpression of wild-type (WT) CCN1. Forced expression of the CCN1 mutant TM, which abrogates all the T1, H1, and H2 binding sites to α₆β₁, failed to bypass the estrogen requirement for anchorage-independent growth or to promote resistance to tamoxifen. Wild-type CCN1 promoted estradiol-independent transcriptional activity of ERα and enhanced ERα agonist response to tamoxifen. The α₆β₁-binding-defective TM-CCN1 mutant lost the ERα co-activator-like behavior of WT-CCN1. Co-immunoprecipitation assays revealed a direct interaction between endogenous CCN1 and ERα, and in vitro approaches confirmed the ability of recombinant CCN1 to bind ERα. CCN1 signaling via α₆β₁, but not via α_vβ₃, drives an endocrine resistance phenotype that involves a direct binding of CCN1 to ERα to regulate its transcriptional activity in ER+ BC cells.

Single-cell RNA-seq recognized the initiator of epithelial ovarian cancer recurrence

Epithelial ovarian cancers (EOCs) are sensitive to chemotherapy but will ultimately relapse and develop drug resistance. The origin of EOC recurrence has been elusive due to intra-tumor heterogeneity. Here we performed single-cell RNA sequencing (scRNA-seq) in 13,369 cells from primary, untreated peritoneal metastasis, and relapse tumors. We used time-resolved analysis to chart the developmental sequence of cells from the metastatic tumors, then traced the earliest replanting cells back to the primary tumors. We discovered seven distinct subpopulations in primary tumors where the CYR61⁺ "stress" subpopulation was identified as the relapse-initiators. Furthermore, a subpopulation of RGS5⁺ cancer-associated fibroblasts (CAFs) was found to strongly support tumor metastasis. The combined CYR61/RGS5 expression scores significantly correlated with the relapse-free-survival of EOC patients and can be used as predictors of EOC recurrence. Our study provides insights into the mechanism of EOC recurrence and presents CYR61⁺ relapse-initiating cells as potential therapeutic targets to prevent EOC relapse.

Drug Resistance in Glioma Cells Induced by a Mesenchymal-Amoeboid Migratory Switch

Cancer cell invasion is a precondition for tumour metastasis and represents one of the most devastating characteristics of cancer. The development of drugs targeting cell migration, known as migrastatics, may improve the treatment of highly invasive tumours such as glioblastoma (GBM). In this study, investigations into the role of the cell adhesion protein Cellular communication network factor 1 (CCN1, also known as CYR61) in GBM cell migration uncovered a drug resistance mechanism adopted by cells when treated with the small molecule inhibitor CCG-1423. This inhibitor binds to importin α/β inhibiting the nuclear translocation of the transcriptional co-activator MKL1, thus preventing downstream effects including migration. Despite this reported role as an inhibitor of cell migration, we found that CCG-1423 treatment did not inhibit GBM cell migration. However, we could observe cells now migrating by mesenchymal-amoeboid transition (MAT). Furthermore, we present evidence that CCN1 plays a critical role in the progression of GBM with increased expression in higher-grade tumours and matched blood samples. These findings support a potential role for CCN1 as a biomarker for the monitoring and potentially early prediction of GBM recurrence, therefore as such could help to improve treatment of and increase survival rates of this devastating disease.

Blood-based detection of lung cancer using cysteine-rich angiogenic inducer 61 (CYR61) as a circulating protein biomarker: a pilot study

Lung cancer is the most often diagnosed cancer and the main cause of cancer deaths in the world compared with other tumor entities. To date, the only screening method for high‐risk lung cancer patients is low‐dosed computed tomography which still suffers from high false‐positive rates and overdiagnosis. Therefore, there is an obvious need to identify biomarkers for the detection of lung cancer that could be used to guide the use of low‐dosed computed tomography or other imaging procedures. We aimed to assess the performance of the protein cysteine‐rich angiogenic inducer 61 (CYR61) as a circulating biomarker for the detection of lung cancer. CYR61 concentrations in plasma were significantly elevated in 87 lung cancer patients (13.7 ± 18.6 ng·mL⁻¹) compared with 150 healthy controls (0.29 ± 0.22 ng·mL⁻¹). Subset analysis stratified by sex revealed increased CYR61 concentrations for adenocarcinoma and squamous cell carcinoma in men compared with women. For male lung cancer patients versus male healthy controls, the sensitivity was 84% at a specificity of 100%, whereas for females, the sensitivity was 27% at a specificity of 99%. The determination of circulating CYR61 protein in plasma might improve the detection of lung cancer in men. The findings of this pilot study support further verification of CYR61 as a biomarker for lung cancer detection in men. Additionally, CYR61 is significantly elevated in women but sensitivity and specificity for CYR61 are too low for the improvement of the detection of lung cancer in women.

Serum CYR61 as a potential biomarker for the diagnosis of esophagogastric junction tumor

BACKGROUND

Esophagogastric junction tumor (EGJ) is a rare but fatal disease with a rapid rising incidence worldwide in the late 20 years, and it lacks a convenient and safe method for diagnosis. The present study aimed to evaluate the potential of serum CYR61 as a biomarker for the diagnosis of EGJ tumor.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to estimate CYR61 levels in sera of 152 EGJ tumor patients and 137 normal controls. Receiver operating characteristics (ROC) was carried out to evaluate the diagnostic accuracy. The Mann-Whitney's U test was used to compare the difference of serum levels of CYR61 between groups. And chi-square tests were employed to estimate the correlation of the positive rate of serum CYR61 between/among subgroups.

RESULTS

Serum CYR61 levels were statistically lower in EGJ tumor and early-stage EGJ tumor patients than those in normal controls (P<0.0001). The sensitivity, specificity and the area under the curve (AUC) of this biomarker in EGJ tumor were 88.2%, 43.8% and 0.691, respectively, and those for early stage of EGJ tumor were 80.0%, 66.4% and 0.722, respectively. Analyses showed that there was no correlation between the clinical data and the levels of CYR61 (P>0.05).

CONCLUSION

The present study showed that CYR61 might be a potential biomarker to assist the diagnosis of EGJ tumor.

CCN Family Proteins in Cancer: Insight Into Their Structures and Coordination Role in Tumor Microenvironment

The crosstalk between tumor cells and the tumor microenvironment (TME), triggers a variety of critical signaling pathways and promotes the malignant progression of cancer. The success rate of cancer therapy through targeting single molecule of this crosstalk may be extremely low, whereas co-targeting multiple components could be complicated design and likely to have more side effects. The six members of cellular communication network (CCN) family proteins are scaffolding proteins that may govern the TME, and several studies have shown targeted therapy of CCN family proteins may be effective for the treatment of cancer. CCN protein family shares similar structures, and they mutually reinforce and neutralize each other to serve various roles that are tightly regulated in a spatiotemporal manner by the TME. Here, we review the current knowledge on the structures and roles of CCN proteins in different types of cancer. We also analyze CCN mRNA expression, and reasons for its diverse relationship to prognosis in different cancers. In this review, we conclude that the discrepant functions of CCN proteins in different types of cancer are attributed to diverse TME and CCN truncated isoforms, and speculate that targeting CCN proteins to rebalance the TME could be a potent anti-cancer strategy.

MITF is a driver oncogene and potential therapeutic target in kidney angiomyolipoma tumors through transcriptional regulation of CYR61

Tuberous sclerosis complex (TSC) is an autosomal dominant tumor suppressor syndrome, characterized by tumor development in multiple organs, including renal angiomyolipoma. Biallelic loss of TSC1 or TSC2 is a known genetic driver of angiomyolipoma development, however, whether an altered transcriptional repertoire contributes to TSC-associated tumorigenesis is unknown. RNA-seq analyses showed that MITF A isoform (MITF-A) was consistently highly expressed in angiomyolipoma, immunohistochemistry showed microphthalmia-associated transcription factor nuclear localization, and Chromatin immuno-Precipitation Sequencing analysis showed that the MITF-A transcriptional start site was highly enriched with H3K27ac marks. Using the angiomyolipoma cell line 621-101, MITF knockout (MITF.KO) and MITF-A overexpressing (MITF.OE) cell lines were generated. MITF.KO cells showed markedly reduced growth and invasion in vitro, and were unable to form xenografted tumors. In contrast, MITF.OE cells grew faster in vitro and as xenografted tumors compared to control cells. RNA-Seq analysis showed that both ID2 and Cysteine-rich angiogenic inducer 61 (CYR61) expression levels were increased in the MITF.OE cells and reduced in the MITF.KO cells, and luciferase assays showed this was due to transcriptional effects. Importantly, CYR61 overexpression rescued MITF.KO cell growth in vitro and tumor growth in vivo. These findings suggest that MITF-A is a transcriptional oncogenic driver of angiomyolipoma tumor development, acting through regulation of CYR61.

Circ-GLI1 promotes metastasis in melanoma through interacting with p70S6K2 to activate Hedgehog/GLI1 and Wnt/β-catenin pathways and upregulate Cyr61

Circular RNAs (circRNAs) are emerging regulators in the development of human cancers. However, the role of circRNAs in melanoma is poorly understood. Microarray analysis and qRT-PCR was applied to screen out circRNAs that were differentially expressed in melanoma cells compared to normal cells. Currently, we first proved that inhibition of CYR61, an angiogenesis factor with controversial functions in melanoma, restrained cell migration, invasion and angiogenesis in melanoma. Thereafter, a novel circRNA hsa_circ_0027247 derived from GLI1 (circ-GLI1) was identified to positively modulate CYR61 expression in melanoma cell lines. Besides, silencing circ-GLI1 hindered melanoma cell metastasis as well. Interestingly, we unveiled that circ-GLI1 enhanced CYR61 transcription by an indirect manner. Meanwhile, circ-GLI1 activated Hedgehog/GLI1 and Wnt/β-catenin pathways by affecting the degradation of GLI1 and β-catenin. Moreover, we found that circ-GLI1 interacted with p70S6K2 to induce GSK3β phosphorylation at Ser9, and therefore blocked the binding of GSK3β with GLI1 and β-catenin so as to elevate their protein expression. Of note, CYR61 was transcriptionally activated by MYC, a well-recognized downstream target of both GLI1 and β-catenin. In conclusion, circ-GLI1 exacerbates the metastasis and angiogenesis of melanoma by upregulating Cyr61 via p70S6K2-dependent activation of Hedgehog/GLI1 and Wnt/β-catenin pathways.

Molecular Dynamics in Esophageal Adenocarcinoma: Who's in Control?

Esophageal adenocarcinoma (EAC) is one of the fastest-growing cancers in the world. It occurs primarily due to the chronic gastroesophageal reflux disease (GERD), during which the esophageal epithelium is frequently exposed to the acidic fluid coming up from the stomach. This triggers gene mutations in the esophageal cells, which may lead to EAC development. While p53 is activated to get rid of the mutated cells, NFκB orchestrates the remaining cells to heal the wound. However, if the mutations happen to TP53 (a common occasion), the mutant product turns to support tumorigenesis. In this case, NFκB goes along with the mutant p53 to facilitate cancer progression. TRAIL is one of the cytokines produced in response to GERD episodes and it can kill cancer cells selectively, but its clinical use has not been as successful as expected, because some highly sophisticated defense mechanisms against TRAIL have developed during the malignancy. To clear the obstacles for TRAIL action, using a second agent to disarm the cancer cells is required. CCN1 appears to be such a molecule. While supporting normal esophageal cell growth, CCN1 suppresses malignant transformation by inhibiting NFκB and kills the EAC cell through TRAIL-mediated apoptosis.

Pericyte FAK negatively regulates Gas6/Axl signalling to suppress tumour angiogenesis and tumour growth

The overexpression of the protein tyrosine kinase, Focal adhesion kinase (FAK), in endothelial cells has implicated its requirement in angiogenesis and tumour growth, but how pericyte FAK regulates tumour angiogenesis is unknown. We show that pericyte FAK regulates tumour growth and angiogenesis in multiple mouse models of melanoma, lung carcinoma and pancreatic B-cell insulinoma and provide evidence that loss of pericyte FAK enhances Gas6-stimulated phosphorylation of the receptor tyrosine kinase, Axl with an upregulation of Cyr61, driving enhanced tumour growth. We further show that pericyte derived Cyr61 instructs tumour cells to elevate expression of the proangiogenic/protumourigenic transmembrane receptor Tissue Factor. Finally, in human melanoma we show that when 50% or more tumour blood vessels are pericyte-FAK negative, melanoma patients are stratified into those with increased tumour size, enhanced blood vessel density and metastasis. Overall our data uncover a previously unknown mechanism of tumour growth by pericytes that is controlled by pericyte FAK.

A potential prognostic model based on miRNA expression profile in The Cancer Genome Atlas for bladder cancer patients

Background

This study aimed to construct prognostic model by screening prognostic miRNA signature of bladder cancer.

Methods

The miRNA expression profile data of bladder cancer (BC) in The Cancer Genome Atlas (TCGA) were obtained and randomly divided into the training set and the validation set. Differentially expressed miRNAs (DEMs) between BC and normal control samples in the training set were firstly identified, and DEMs related to prognosis were screened by Cox Regression analysis. Then, the MiR Score system was constructed using X-Tile based cutoff points and verified in the validation set. The prognostic clinical factors are selected out by univariate and multivariate Cox Regression analysis. Finally, the mRNAs related to prognosis were screened and the biological pathway analysis was carried out.

Results

We identified the 7-miRNA signature was significantly associated with the patient’s Overall Survival (OS). A prognostic model was constructed based on the prognostic 7-miRNA signature, and possessed a relative satisfying predicted ability both in the training set and validation set. In addition, univariate and multivariate Cox Regression analysis showed that age, lymphovascular invasion and MiR Score were considered as independent prognostic factors in BC patients. Furthermore, based on MiR Score prognostic model, several differentially expressed genes (DEGs), such as WISP3 and UNC5C, as well as their related biological pathway(s), including cell–cell adhesion and neuroactive ligand-receptor interaction, were considered to be related to BC prognosis.

Conclusion

The prognostic model which was constructed based on the prognostic 7-miRNA signature presented a high predictive ability for BC.

Overexpression of connective tissue growth factor is associated with tumor progression and unfavorable prognosis in endometrial cancer

OBJECTIVES

This study was to explore the prognostic value of connective tissue growth factor (CTGF) expression in endometrial cancer (EC).

METHODS

We compared CTGF expression in 198 samples from patients with endometrial cancer and 50 samples from patients with healthy endometrial tissues as determined by immunohistochemistry.

RESULTS

Expression of CTGF was significantly higher in endometrial cancers as compared to normal endometrial tissues. Positive CTGF expression displayed a strong association with CA125 level, histological grade, depth of myometrial invasion and the International Federation of Gynecology and Obstetrics (FIGO) stage. Our findings revealed histological grade, depth of myometrial invasion, FIGO stage, vascular/lymphatic invasion, and the CTGF expression are related to 5-year survival in patients with endometrial cancer. Positive CTGF expression, lymph node status, as well as vascular/lymphatic invasion, were identified as independent prognostic factors in endometrial cancer.

CONCLUTIONS

Over-expression of CTGF is an independent prognostic factor that will allow the successful differentiation of high-risk population from the group of patients with stage III-IV endometrial cancer. The up-regulation of CTGF may contribute to the progression of endometrial cancer and serve as a new prognostic biomarker in patients with endometrial cancer survival.

Role of the CCN protein family in cancer

The CCN protein family is composed of six matricellular proteins, which serve regulatory roles rather than structural roles in the extracellular matrix. First identified as secreted proteins which are induced by oncogenes, the acronym CCN came from the names of the first three members: CYR61, CTGF, and NOV. All six members of the CCN family consist of four cysteine-rich modular domains. CCN proteins are known to regulate cell adhesion, proliferation, differentiation, and apoptosis. In addition, CCN proteins are associated with cardiovascular and skeletal development, injury repair, inflammation, and cancer. They function either through binding to integrin receptors or by regulating the expression and activity of growth factors and cytokines. Given their diverse roles related to the pathology of certain diseases such as fibrosis, arthritis, atherosclerosis, diabetic nephropathy, retinopathy, and cancer, there are many emerging studies targeting CCN protein signaling pathways in attempts to elucidate their potentials as therapeutic targets. [BMB Reports 2018; 51(10): 486-493].

Current progress in the inflammatory background of angiogenesis in gynecological cancers

A tumor growth depends on the potency of the tumor to support itself with nutrients and oxygen. The development of a vascular network within the tumor is key to its survival. The permanent contest between the tumor and its host involves tumor cells on one side and an immunological system and tissue stroma on the other. The angiogenesis is not only a specialty of the tumor, but it also depends on this complex multidirectional interaction. The most common gynecological cancers, cervical, endometrial and ovarian carcinoma are good examples for studying this problem. In this review, we aim to show that an inflammatory response against a tumor can be reverted into an undesirable process leading to the development of a vascular network within the tumor and, subsequently, further growth of the tumor and progression of a disease. Therefore, a key for tumor management should be searched within the immunological system, rather than focused on cell cycle and anti-angiogenic treatment only.

Urinary Cysteine-Rich Protein 61 and Trefoil Factor 3 as Diagnostic Biomarkers for Colorectal Cancer

Since a fecal occult blood test for colorectal cancer (CRC) does not offer sufficient diagnostic power for CRC, novel non-invasive biomarkers are hopeful for CRC screening. We conducted the current study to discover non-invasive urinary biomarkers for diagnosing CRC. Among urine samples from 258 patients (CRC, n = 148; healthy controls, n = 110), a cohort of 176 patients composed of 88 patients with GC and 88 healthy controls was selected after age- and sex-matching using propensity score. This cohort was then randomly divided into 2 groups: 53 pairs (106 patients) in the training cohort, and 35 pairs (70 patients) in the validation cohort. No significant differences were found for baseline characteristics between the CRC and healthy control groups in both training and validation cohorts. On multivariate analysis in the training cohort, urinary levels of cysteine-rich protein 61 (uCyr61) and trefoil factor 3 (uTFF3) were identified as independent significant diagnostic markers for CRC. Moreover, uCyr61 alone and the combination of uCyr61 and uTFF3 allowed significant differentiation between healthy controls and CRC groups in the training set (uCyr61: area under the curve (AUC) = 0.745 [95% CI, 0.653–0.838]; uCyr61 + uTFF3: AUC = 0.753 [95% CI, 0.659–0.847]). In the validation cohort, uCyr61 and uTFF3 were significantly higher in the CRC group than in the healthy control group, and they also allowed significant differentiation between healthy control and CRC groups (uCyr61: AUC = 0.696 [95% CI, 0.571–0.822]; uTFF3: AUC = 0.639 [95% CI, 0.508–0.770]; uCyr61 + uTFF3: AUC = 0.720 [95% CI, 0.599–0.841]), as in the training cohort. A panel combining uCyr61 and uTFF3 offers a promising non-invasive biomarker for diagnosing CRC.

Molecular signatures for CCN1, p21 and p27 in progressive mantle cell lymphoma

Mantle cell lymphoma (MCL) is a comparatively rare non-Hodgkin's lymphoma characterised by overexpression of cyclin D1. Many patients present with or progress to advanced stage disease within 3 years. MCL is considered an incurable disease with median survival between 3 and 4 years. We have investigated the role(s) of CCN1 (CYR61) and cell cycle regulators in progressive MCL. We have used the human MCL cell lines REC1 < G519 < JVM2 as a model for disease aggression. The magnitude of CCN1 expression in human MCL cells is REC1 > G519 > JVM2 cells by RQ-PCR, depicting a decrease in CCN1 expression with disease progression. Investigation of CCN1 isoform expression by western blotting showed that whilst expression of full-length CCN1 was barely altered in the cell lines, expression of truncated forms (18-20 and 28-30 kDa) decreased with disease progression. We have then demonstrated that cyclin D1 and cyclin dependent kinase inhibitors (p21^CIP1and p27^KIP1) are also involved in disease progression. Cyclin D1 was highly expressed in REC1 cells (OD: 1.0), reduced to one fifth in G519 cells (OD: 0.2) and not detected by western blotting in JVM2 cells. p27^KIP1 followed a similar profile of expression as cyclin D1. Conversely, p21^CIP1 was absent in the REC1 cells and showed increasing expression in G519 and JVM2 cells. Subcellular localization detected p21^CIP1/ p27^KIP1 primarily within the cytoplasm and absent from the nucleus, consistent with altered roles in treatment resistance. Dysregulation of the CCN1 truncated forms are associated with MCL progression. In conjunction with reduced expression of cyclin D1 and increased expression of p21, this molecular signature may depict aggressive disease and treatment resistance.

Anticancer Activity of Metformin, an Antidiabetic Drug, Against Ovarian Cancer Cells Involves Inhibition of Cysteine-Rich 61 (Cyr61)/Akt/Mammalian Target of Rapamycin (mTOR) Signaling Pathway

Background

Ovarian cancer is considered one of the lethal cancers responsible for high mortality and morbidity across the world. The prognosis and the survival rate of ovarian cancer is far from decent. Cysteine-rich 61 (Cyr61) also known as CCN1, is a member of CCN-family of growth factors, reported to be significantly overexpressed in several malignancies which include, but are not limited to, ovarian cancer. Recent studies have revealed that women with type 2 diabetes mellitus have an elevated risk of ovarian cancer. Hence, administration of an antidiabetic drug with anticancer effects such as metformin may act as an effective therapeutic regime against ovarian cancer.

Material/Methods

Cell viability and apoptosis were examined by MTT and Annexin V/PI double staining respectively. Cell migration was determined by Boyden Chamber assay. Transient knockdown of Cyr61 in ovarian cancer cells was achieved by transecting the cells with siRNA for Cyr61using Lipofectamine 2000.

Results

Our results indicated that treatment of ovarian cancer cells with metformin caused significant downregulation of Cyr61 protein expression levels ultimately favoring apoptosis. Transient knockdown of Cyr61 resulted in the inhibition of cell proliferation and migration. This was also associated with the concomitant downregulation of pAkt and pmTOR confirming the role of Cyr61 as an upstream modulator of Akt signaling. Conversely the extracellular supplementation of recombinant Cyr61 attenuates the cytotoxic properties of metformin in ovarian cancer cells.

Conclusions

Taken together, we concluded that metformin exhibits anticancer effects and Cyr61 acts as a direct target for metformin in ovarian cancer cells.

The matricellular protein CYR61 promotes breast cancer lung metastasis by facilitating tumor cell extravasation and suppressing anoikis

Matricellular proteins play multiple roles in primary tumor growth, local invasion and tumor angiogenesis. However, their contribution to metastasis and the putative mechanisms involved are less well characterized. In ER-negative human breast cancer, elevated expression levels of the matricellular protein Cysteine-rich angiogenic inducer 61 (CYR61) are associated with more aggressive progression. Here, we investigated the role of CYR61 in breast cancer lung metastasis using the triple negative human breast cancer cell lines MDA-MB-231 and SUM159. Silencing of CYR61 significantly decreased lung metastasis from tumors orthotopically implanted in pre-irradiated or naive mammary tissue and upon tail vein injection. Constitutive CYR61 silencing impaired cancer cell extravasation to the lung during the first 24 hours after tail vein injection. In contrast, CYR61 inducible silencing starting 24 hours after cancer cell injection had no impact on lung metastasis formation. In vitro experiments revealed that CYR61 silencing decreased cancer cell transendothelial migration and motility, reduced CYR61 levels present at the cell surface and sensitized cancer cells to anoikis. Furthermore, we demonstrate that CYR61-dependent cell survival under non-adhesive conditions relied, at least partially, on β1 integrin ligation and AMPKα signaling while it was independent of AKT, FAK and ERK1/2 activation. Our data provide the first evidence that CYR61 promotes breast cancer lung metastasis by facilitating tumor cell extravasation and protecting from anoikis during initial seeding to the lung. The uncovered CYR61-β1 integrin-AMPKα axis may serve as a potential therapeutic target to prevent breast cancer metastasis to the lung.

CCN1 sensitizes esophageal cancer cells to TRAIL-mediated apoptosis

TRAIL is one of the best anti-cancer molecules in our body. It kills a variety of cancer cells that are resistant to conventional chemotherapy, without causing much negative impact on normal cells, because its death receptors are almost exclusively found on cancer cells. However, some cancer cells are not sensitive to TRAIL treatment, even though they express its death receptors. A second molecule is needed to help TRAIL to complete its mission. Finding such molecules now becomes a top priority in cancer research. Our study shows that CCN1 is such a molecule. CCN1 was highly expressed in the esophageal epithelium of the patients suffering from gastroesophageal reflux disease, but faded away as the situation worsened towards adenocarcinoma. Treating the tumor cells with CCN1 resulted in apoptosis, while the same treatment to the normal cells only nourished cell growth. It was TRAIL that mediated this process. Apparently, CCN1 altered the expression profile of TRAIL and its receptors in tumor cells, namely, activating TRAIL and its death receptors and shutting down its decoy receptors. CCN1 and TRAIL worked as a team to put the cancer cells to death, as elimination of either one failed apoptosis.

Connective tissue growth factor mediates TGF-β1-induced low-grade serous ovarian tumor cell apoptosis

Ovarian low-grade serous carcinoma (LGSC) is a rare disease and is now considered to be a distinct entity from high-grade serous carcinoma (HGSC), which is the most common and malignant form of epithelial ovarian cancer. Connective tissue growth factor (CTGF) is a secreted matricellular protein that has been shown to modulate many biological functions by interacting with multiple molecules in the microenvironment. Increasing evidence indicates that aberrant expression of CTGF is associated with cancer development and progression. Transforming growth factor-β1 (TGF-β1) is a well-known molecule that can strongly up-regulate CTGF expression in different types of normal and cancer cells. Our previous study demonstrated that TGF-β1 induces apoptosis of LGSC cells. However, the effect of TGF-β1 on CTGF expression in LGSC needs to be defined. In addition, whether CTGF mediates TGF-β1-induced LGSC cell apoptosis remains unknown. In the present study, we show that TGF-β1 treatment up-regulates CTGF expression by activating SMAD3 signaling in two human LGSC cell lines. Additionally, siRNA-mediated CTGF knockdown attenuates TGF-β1-induced cell apoptosis. Moreover, our results show that the inhibitory effect of the CTGF knockdown on TGF-β1-induced cell apoptosis is mediated by down-regulating SMAD3 expression. This study demonstrates an important role for CTGF in mediating the pro-apoptotic effects of TGF-β1 on LGCS.

Molecular biomarkers to predict response to neoadjuvant chemotherapy for bladder cancer

Cystectomy is the gold standard for treatment of localized muscle-invasive bladder cancer. However, about 50% of patients develop metastases within 2years after cystectomy and subsequently die for the disease. Neoadjuvant cisplatin-based chemotherapy before cystectomy improves the overall survival in patients with muscle-invasive bladder cancer, and pathological response to neoadjuvant treatment (downstaging to ⩽pT1 at cystectomy) is a strong predictor of better disease-specific survival. Nevertheless, some patients do not benefit from neoadjuvant therapy. The identification of reliable biomarkers that could enable the clinicians to identify patients who will really benefit from neoadjuvant chemotherapy is a major issue. This approach could lead to individualized therapy, in order to optimize the chance of response, avoiding the impact of neoadjuvant treatment on quality of life and the delay of cystectomy in non-responder patients. However, no molecular predictive biomarkers have shown clinical utility. This paper aims to review currently available data about biomarkers predictive of response to neoadjuvant chemotherapy in muscle-invasive bladder cancer.

The matricellular protein CYR61 interferes with normal pancreatic islets architecture and promotes pancreatic neuroendocrine tumor progression

The significance of matricellular proteins during development and cancer progression is widely recognized. However, how these proteins actively contribute to physiological development and pathological cancer progression is only partially elucidated. In this study, we investigated the role of the matricellular protein Cysteine-rich 61 (CYR61) in pancreatic islet development and carcinogenesis. Transgenic expression of CYR61 in β cells (Rip1CYR mice) caused irregular islets morphology and distorted sorting of α cells, but did not alter islets size, number or vascularization. To investigate the function of CYR61 during carcinogenesis, we crossed Rip1CYR mice with Rip1Tag2 mice, a well-established model of β cell carcinogenesis. Beta tumors in Rip1Tag2CYR mice were larger, more invasive and more vascularized compared to tumors in Rip1Tag2 mice. The effect of CYR61 on angiogenesis was fully abrogated by treating mice with the anti-VEGFR2 mAb DC101. Results from in vitro assays demonstrated that CYR61 modulated integrin α6β1-dependent invasion and adhesion without altering its expression. Taken together, these results show that CYR61 expression in pancreatic β cells interferes with normal islet architecture, promotes islet tumor growth, invasion and VEGF/VERGFR-2-dependent tumor angiogenesis. Taken together, these observations demonstrate that CYR61 acts as a tumor-promoting gene in pancreatic neuroendocrine tumors.

Connective tissue growth factor as a novel therapeutic target in high grade serous ovarian cancer

Ovarian cancer is the most common cause of death among women with gynecologic cancer. We examined molecular profiles of fibroblasts from normal ovary and high-grade serous ovarian tumors to identify novel therapeutic targets involved in tumor progression. We identified 2,300 genes that are significantly differentially expressed in tumor-associated fibroblasts. Fibroblast expression of one of these genes, connective tissue growth factor (CTGF), was confirmed by immunohistochemistry. CTGF protein expression in ovarian tumor fibroblasts significantly correlated with gene expression levels. CTGF is a secreted component of the tumor microenvironment and is being pursued as a therapeutic target in pancreatic cancer. We examined its effect in in vitro and ex vivo ovarian cancer models, and examined associations between CTGF expression and clinico-pathologic characteristics in patients. CTGF promotes migration and peritoneal adhesion of ovarian cancer cells. These effects are abrogated by FG-3019, a human monoclonal antibody against CTGF, currently under clinical investigation as a therapeutic agent. Immunohistochemical analyses of high-grade serous ovarian tumors reveal that the highest level of tumor stromal CTGF expression was correlated with the poorest prognosis. Our findings identify CTGF as a promoter of peritoneal adhesion, likely to mediate metastasis, and a potential therapeutic target in high-grade serous ovarian cancer. These results warrant further studies into the therapeutic efficacy of FG-3019 in high-grade serous ovarian cancer.

Differential expression of CCN family members CYR611, CTGF and NOV in gastric cancer and their association with disease progression

CCN is an acronym for cysteine-rich protein 61 (CYR61), connective tissue growth factor (CTGF) and nephroblastoma overexpressed (NOV). Aberrations of certain CCN members including CYR61, CTGF, Wnt1-inducible signalling pathway protein (WISP)-1 and -3 have been reported in gastric cancer. The present study aimed to examine the clinical relevance of NOV along with CYR61 and CTGF in gastric cancer by analysing their transcript levels. CYR61, CTGF and NOV transcript expression in 324 gastric cancer samples with paired adjacent normal gastric tissues were determined using real-time quantitative PCR and the results were statistically analysed against patient clinicopathological data using SPSS software. NOV mRNA levels in gastric cancer tissues were significantly elevated when compared with levels in their paired adjacent non-cancerous tissues. Local advanced tumours with invasive expansion (T3 and T4) expressed higher levels of NOV (p=0.013) compared with the less invasive tumours (T1 and T2). CYR61 transcript levels were also significantly increased in gastric cancers compared with levels in the adjacent non-cancerous tissues. Kaplan-Meier survival curves revealed that patients with CYR61-low transcript levels had longer overall survival (OS) (p=0.018) and disease-free survival (DFS) (p=0.015). NOV overexpression promoted the in vitro proliferation of AGS cells while the knockdown resulted in a reduced proliferation of HGC27 cells. A similar effect was observed for the invasion of these two gastric cancer cell lines. NOV expression was increased in gastric cancer which was associated with local invasion and distant metastases. Taken together, the expression of NOV and CYR61 was increased in gastric cancer. The elevated expression of CYR61 was associated with poorer survival. NOV promoted proliferation and invasion of gastric cancer cells. Further investigations may highlight their predictive and therapeutic potential in gastric cancer.

Matricellular proteins in drug delivery: Therapeutic targets, active agents, and therapeutic localization

Extracellular matrix is composed of a complex array of molecules that together provide structural and functional support to cells. These properties are mainly mediated by the activity of collagenous and elastic fibers, proteoglycans, and proteins such as fibronectin and laminin. ECM composition is tissue-specific and could include matricellular proteins whose primary role is to modulate cell-matrix interactions. In adults, matricellular proteins are primarily expressed during injury, inflammation and disease. Particularly, they are closely associated with the progression and prognosis of cardiovascular and fibrotic diseases, and cancer. This review aims to provide an overview of the potential use of matricellular proteins in drug delivery including the generation of therapeutic agents based on the properties and structures of these proteins as well as their utility as biomarkers for specific diseases.

Emerging role of CCN family proteins in tumorigenesis and cancer metastasis (Review)

The CCN family of proteins comprises the members CCN1, CCN2, CCN3, CCN4, CCN5 and CCN6. They share four evolutionarily conserved functional domains, and usually interact with various cytokines to elicit different biological functions including cell proliferation, adhesion, invasion, migration, embryonic development, angiogenesis, wound healing, fibrosis and inflammation through a variety of signalling pathways. In the past two decades, emerging functions for the CCN proteins (CCNs) have been identified in various types of cancer. Perturbed expression of CCNs has been observed in a variety of malignancies. The aberrant expression of certain CCNs is associated with disease progression and poor prognosis. Insight into the detailed mechanisms involved in CCN-mediated regulation may be useful in understanding their roles and functions in tumorigenesis and cancer metastasis. In this review, we briefly introduced the functions of CCNs, especially in cancer.

The matricellular protein CCN1 suppresses hepatocarcinogenesis by inhibiting compensatory proliferation

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide, and is on the rise in the United States. Previous studies showed that the matricellular protein CCN1 (CYR61) is induced during hepatic injuries and functions to restrict and resolve liver fibrosis. Here we show that CCN1 suppresses hepatocarcinogenesis by inhibiting carcinogen-induced compensatory hepatocyte proliferation, thus limiting the expansion of damaged and potentially oncogenic hepatocytes. Consistent with tumor suppression, CCN1 expression is down-regulated in human HCC. Ccn1^ΔHep mice with hepatocyte-specific deletion of Ccn1 suffer increased HCC tumor multiplicity induced by the hepatocarcinogen diethylnitrosoamine (DEN). Knockin mice (Ccn1^dm/dm) that express an integrin α₆β₁-binding defective CCN1 phenocopied Ccn1^ΔHep mice, indicating that CCN1 acts through its α₆β₁ binding sites in this context. CCN1 effectively inhibits EGFR-dependent hepatocyte proliferation through integrin α₆-mediated accumulation of reaction oxygen species (ROS), thereby triggering p53 activation and cell cycle block. Consequently, Ccn1^dm/dm mice exhibit diminished p53 activation and elevated compensatory hepatocyte proliferation, resulting in increased HCC. Furthermore, we show that a single dose of the EGFR inhibitor erlotinib delivered prior to DEN-induced injury was sufficient to block compensatory proliferation and annihilate development of HCC nodules observed 8 months later, suggesting potential chemoprevention by targeting CCN1-inhibitable EGFR-dependent hepatocyte proliferation. Together, these results show that CCN1 is an injury response protein that functions not only to restrict fibrosis in the liver, but also to suppress hepatocarcinogenesis by inhibiting EGFR-dependent hepatocyte compensatory proliferation.

Serum Cyr61 is associated with clinical disease activity and inflammation in patients with systemic lupus erythematosus

Our previous studies have shown that secreted extracellular matrix-associated protein Cysteine rich angiogenic inducer 61 (Cyr61), a novel proinflammatory factor, is involved in the pathogenesis of rheumatoid arthritis (RA). However, whether Cyr61 has any effect in systemic lupus erythematosus (SLE) remains unknown. This study aims to assess the level of serum Cyr61 and to investigate the association of serum Cyr61 and clinical disease activity in SLE. We found the level of serum Cyr61 in patients with SLE was significantly higher than healthy controls (P < 0.001), and Cyr61 was high expressed in renal tubule of lupus nephritis compared to control. The sensitivity of Cyr61 in diagnosis of SLE was 47.3%. In receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) was 0.830, with a 95% confidence interval (CI) from 0.776 to 0.885. Cyr61 was present in 60.0%, 54.5%, and 41.5% of anti-double stranded DNA (dsDNA), anti-antinuclear antibodies (ANA), and anti-Sm negative SLE patients, respectively. Serum Cyr61 levels were significantly higher in high systemic lupus erythematosus disease activity index (SLEDAI) group than that in low SLEDAI group (P = 0.003). Correlation analyzes showed a significant negative correlation between serum Cyr61 and complements (C3) (P = 0.015), C4 (P = 0.04). Moreover, increased Cyr61 level in SLE was associated with serum level of TNF-α, interleukin 6 (IL-6), and IL-17. In conclusion, serum Cyr61 was increased in patients with SLE which was associated with clinical disease activity and inflammation in SLE, suggesting Cyr61 may be a novel potential auxiliary marker for the diagnosis of SLE.

Cyr61 promotes CD204 expression and the migration of macrophages via MEK/ERK pathway in esophageal squamous cell carcinoma

Tumor-associated macrophages (TAMs) are known to be involved in the progression of various human malignancies. We previously demonstrated that CD204 was a useful marker for TAMs contributing to the angiogenesis, progression, and prognosis of human esophageal squamous cell carcinoma (ESCC). We also showed that conditioned media of ESCC cell lines induced CD204 expression in THP-1 human monocytic leukemia cells. Here, we performed a cDNA microarray analysis between THP-1 cells stimulated with TPA (macrophage [MΦ]-like THP-1 cells) treated with and without conditioned medium of ESCC cell line to clarify the molecular characteristics of TAMs in ESCC. From the microarray data, we discovered that Cyr61 was induced in CD204-positive-differentiated THP-1 cells (TAM-like THP-1 cells). In the ESCC microenvironment, not only cancer cells but also TAMs expressed Cyr61. Interestingly, the expression levels of Cyr61 showed a significant positive correlation with the number of CD204-positive macrophages in ESCCs by immunohistochemistry. Recombinant human Cyr61 (rhCyr61) promoted cell migration and induced the expression of CD204 along with the activation of the MEK/ERK pathway in MΦ-like THP-1 cells. Pretreatment with a MEK1/2 inhibitor significantly inhibited not only the Cyr61-mediated migration but also the CD204 expression in the MΦ-like THP-1 cells. These results suggest that Cyr61 may contribute to the expression of CD204 and the promotion of cell migration via the MEK/ERK pathway in TAMs in the ESCC microenvironment.

Inhibiting CCN1 blocks AML cell growth by disrupting the MEK/ERK pathway

Background

CCN1 plays distinct roles in various tumor types, but little is known regarding the role of CCN1 in leukemia.

Methods

We analyzed CCN1 protein expression in leukemia cell lines and in AML bone marrow samples. We also evaluated the effects of antibody- or siRNA-mediated inhibition of CCN1 on the growth of two AML cell lines (U937 and Kasumi-1 cells) and on the MEK/ERK pathway, β-catenin and other related genes.

Results

U937 and Kasumi-1 cells had markedly higher CCN1 expression than the 5 other leukemia cell lines, and CCN1 protein expression was higher in the AML bone marrow samples than in the normal bone marrow samples. Blocking CCN1 with an antibody in U937 and Kasumi-1 cells suppressed proliferation, increased apoptosis, down-regulated Bcl-xL and c-Myc expression, up-regulated Bax expression, and had no effect on Survivin. siRNA-mediated down-regulation of CCN1 inhibited the proliferation and colony formation of U937 and Kasumi-1 cells and increased cytarabine-induced apoptosis. Furthermore, CCN1 siRNA reduced MEK and ERK phosphorylation without affecting β-catenin; the CCN1 antibody similarly affected MEK and ERK phosphorylation. These changes in phosphorylation could influence the expression of Bcl-xL, c-Myc and Bax in AML cells.

Conclusions

The data suggested that CCN1 is a tumor promoter in AML that acts through the MEK/ERK pathway to up-regulate c-Myc and Bcl-xL and to down-regulate Bax.

CYR61 overexpression associated with the development and poor prognosis of ovarian carcinoma

Cysteine-rich 61 (CYR61) has been proven to be an oncogene with potential predictive and prognostic implications in a variety of human cancers. However, the expression pattern of CYR61 and its role in ovarian carcinoma remains largely unknown. In this study, the mRNA and protein levels of CYR61 in normal ovaries and ovarian carcinoma tissues were evaluated using reverse transcription-polymerase chain reaction, immunohistochemistry, and Western blotting. Compared to normal ovarian tissues, the mRNA and protein levels of CYR61 were significantly higher in ovarian carcinoma tissues. Moreover, receiver operating characteristic (ROC) curve analysis, Spearman's rank correlation, Kaplan-Meier plots, and the Cox proportional hazards regression model were used to investigate the potential association of the CYR61 protein with the development of ovarian carcinoma in an ovarian carcinoma cohort. Based on ROC curve analysis, high expression of CYR61 was defined as a tumor in which more than 70 % of cells were positively stained. Based on this cutoff value, high expression of CYR61 was detected in 51.5 % of invasive carcinomas, 35.3 % of borderline tumors, 25.9 % of cystadenomas, and 20 % in the normal ovaries. In ovarian carcinomas, CYR61 overexpression was associated with advanced FIGO stage. Univariate survival analysis on the ovarian carcinoma cohorts showed that overexpression of CYR61 was associated with poor survival of ovarian cancer patients. Multivariate analysis suggested that the protein level of CYR61 was an independent and significant prognostic factor for ovarian carcinoma. Our results suggest that the CYR61 protein is an important and independent biomarker for prognostic implications of ovarian carcinoma.

Deregulated expression of connective tissue growth factor (CTGF/CCN2) is linked to poor outcome in human cancer

Connective tissue growth factor (CTGF/CCN2) has long been associated with human cancers. The role it plays in these neoplasms is diverse and tumour specific. Recurring patterns in clinical outcome, histological desmoplasia and mechanisms of action have been found. When CTGF is overexpressed compared to low-expressing normal tissue or is underexpressed compared to high-expressing normal tissue, the functional outcome favours tumour survival and disease progression. CTGF acts by altering proliferation, drug resistance, angiogenesis, adhesion and migration contributing to metastasis. The pattern of CTGF expression and tumour response helps to clarify the role of this matricellular protein across a multitude of human cancers.

Cyr61 expression is associated with prognosis in patients with colorectal cancer

Background

Cysteine-rich 61 (Cyr61), a member of the CCN protein family, possesses diverse functionality in cellular processes such as adhesion, migration, proliferation, and survival. Cyr61 can also function as an oncogene or a tumour suppressor, depending on the origin of the cancer. Only a few studies have reported Cyr61 expression in colorectal cancer. In this study, we assessed the Cyr61 expression in 251 colorectal cancers with clinical follow up.

Methods

We examined Cyr61 expression in 6 colorectal cancer cell lines (HT29, Colo205, Lovo, HCT116, SW480, SW620) and 20 sets of paired normal and colorectal cancer tissues by western blot. To validate the association of Cyr61 expression with clinicopathological parameters, we assessed Cyr61 expression using tissue microarray analysis of primary colorectal cancer by immunohistochemical analysis.

Results

We verified that all of the cancer cell lines expressed Cyr61; 2 cell lines (HT29 and Colo205) demonstrated Cyr61 expression to a slight extent, while 4 cell lines (Lovo, HCT116, SW480, SW620) demonstrated greater Cyr61 expression than HT29 and Colo205 cell lines. Among the 20 cases of paired normal and tumour tissues, greater Cyr61 expression was observed in 16 (80%) tumour tissues than in normal tissues. Furthermore, 157 out of 251 cases (62.5%) of colorectal cancer examined in this study displayed strong Cyr61 expression. Cyr61 expression was found to be associated with pN (p = 0.018). Moreover, Cyr61 expression was associated with statistically significant cancer-specific mortality (p = 0.029). The duration of survival was significantly lesser in patients with Cyr61 high expression than in patients with Cyr61 low expression (p = 0.001). These results suggest that Cyr61 expression plays several important roles in carcinogenesis and may also be a good prognostic marker for colorectal cancer.

Conclusions

Our data confirmed that Cyr61 was expressed in colorectal cancers and the expression was correlated with worse prognosis of colorectal cancers.

Inhibitory effect of dexamethasone on expression of cysteine-rich 61 protein in airway epithelial cells of allergic mouse models

In order to study whether cysteine-rich 61 protein (cyr61) is involved in the pathogenesis of asthma and its relation to airway inflammation, the effect of dexamethasone (Dxm) on the expression of cyr61 in the lung tissues of asthmatic mice was investigated. Forty BALB/c mice were divided into asthma group (n=15), control group (n=10) and Dxm group (n=15). The asthma group was sensitized and challenged by ovalbumin (OVA). The mice in Dxm group were intraperitoneally administered with Dxm after OVA challenge. The expression of cyr61 in the lung tissues was detected by using immunohistochemistry, and that of eotaxin protein in the bronchoalveolar lavage fluid (BALF) by using enzyme-linked immunosorbent assay (ELISA). The number of inflammatory cells in BALF was also analyzed. The results showed that the cyr61 expression was highest in asthma group (P<0.05), followed by Dxm group (P<0.05) and control group. The cyr61 had a positive correlation with the total nucleated cells (r=0.867, P<0.05), especially eosinophils (r=0.856, P<0.05), and eotaxin level (r=0.983, P<0.05) in the BALF. Our findings suggested that cyr61 is expressed in airway epithelial cells and has a positive correlation with eotaxin and number of airway infiltrating eosinophils.

Expression and clinical significance of connective tissue growth factor in thyroid carcinomas

Objectives

To examine expression of the connective tissue growth factor ( CTGF) gene in human thyroid cancer and establish whether a correlation exists between the presence of CTGF protein and clinicopathological parameters of the disease.

Methods

CTGF protein expression was investigated retrospectively by immunohistochemical analysis of CTGF protein levels in thyroid tumour tissue. Associations between immunohistochemical score and several clinicopathological parameters were examined.

Results

In total, 131 thyroid tissue specimens were included. High levels of CTGF protein were observed in papillary thyroid carcinoma tissue; benign thyroid tumour tissue scored negatively for CTGF protein. In papillary thyroid carcinoma, there was a significant relationship between high CTGF protein levels and Union for International Cancer Control disease stage III–IV, and presence of lymph node metastasis. In papillary thyroid carcinomas, CTGF protein levels were not significantly associated with sex or age.

Conclusions

These findings suggest that the CTGF protein level is increased in papillary thyroid carcinoma cells compared with benign thyroid tumours. CTGF expression might play a role in the development of malignant tumours in the thyroid.

Network-based survival analysis reveals subnetwork signatures for predicting outcomes of ovarian cancer treatment

Cox regression is commonly used to predict the outcome by the time to an event of interest and in addition, identify relevant features for survival analysis in cancer genomics. Due to the high-dimensionality of high-throughput genomic data, existing Cox models trained on any particular dataset usually generalize poorly to other independent datasets. In this paper, we propose a network-based Cox regression model called Net-Cox and applied Net-Cox for a large-scale survival analysis across multiple ovarian cancer datasets. Net-Cox integrates gene network information into the Cox's proportional hazard model to explore the co-expression or functional relation among high-dimensional gene expression features in the gene network. Net-Cox was applied to analyze three independent gene expression datasets including the TCGA ovarian cancer dataset and two other public ovarian cancer datasets. Net-Cox with the network information from gene co-expression or functional relations identified highly consistent signature genes across the three datasets, and because of the better generalization across the datasets, Net-Cox also consistently improved the accuracy of survival prediction over the Cox models regularized by or . This study focused on analyzing the death and recurrence outcomes in the treatment of ovarian carcinoma to identify signature genes that can more reliably predict the events. The signature genes comprise dense protein-protein interaction subnetworks, enriched by extracellular matrix receptors and modulators or by nuclear signaling components downstream of extracellular signal-regulated kinases. In the laboratory validation of the signature genes, a tumor array experiment by protein staining on an independent patient cohort from Mayo Clinic showed that the protein expression of the signature gene FBN1 is a biomarker significantly associated with the early recurrence after 12 months of the treatment in the ovarian cancer patients who are initially sensitive to chemotherapy. Net-Cox toolbox is available at http://compbio.cs.umn.edu/Net-Cox/.

Network-based computational models are attracting increasing attention in studying cancer genomics because molecular networks provide valuable information on the functional organizations of molecules in cells. Survival analysis mostly with the Cox proportional hazard model is widely used to predict or correlate gene expressions with time to an event of interest (outcome) in cancer genomics. Surprisingly, network-based survival analysis has not received enough attention. In this paper, we studied resistance to chemotherapy in ovarian cancer with a network-based Cox model, called Net-Cox. The experiments confirm that networks representing gene co-expression or functional relations can be used to improve the accuracy and the robustness of survival prediction of outcome in ovarian cancer treatment. The study also revealed subnetwork signatures that are enriched by extracellular matrix receptors and modulators and the downstream nuclear signaling components of extracellular signal-regulators, respectively. In particular, FBN1, which was detected as a signature gene of high confidence by Net-Cox with network information, was validated as a biomarker for predicting early recurrence in platinum-sensitive ovarian cancer patients in laboratory.

Inverse expression of cystein-rich 61 (Cyr61/CCN1) and connective tissue growth factor (CTGF/CCN2) in borderline tumors and carcinomas of the ovary

Members of the CCN [cystein-rich 61 (Cyr61)/connective tissue growth factor (CTGF)/nephroblastoma (NOV)] protein family are involved in the regulation of cellular proliferation, apoptosis, and migration and are also assumed to play a role in carcinogenesis. Therefore, we performed a retrospective study to investigate the immunohistochemical expression of both Cyr61 and CTGF in 92 borderline tumors (BOTs) and 107 invasive carcinomas of the ovary (IOCs). To determine their diagnostic and prognostic value, we correlated protein expression with clinicopathologic factors including overall and disease-free survival. Cyr61 and CTGF were found to be inversely expressed in both BOTs and IOCs, with a stronger expression of Cyr61 in IOCs. Moreover, Cyr61 was found to be preferentially expressed in high-grade serous carcinomas, whereas CTGF was found more frequently in low-grade serous carcinomas. Weak Cyr61 levels correlated with both low estrogen receptor and p53 expression (P=0.038, P=0.04, respectively). However, no association was observed between CTGF, estrogen receptor, and p53 expression levels in IOCs. Regarding prognosis, Cyr61 was found to be of no value, but the loss of CTGF was found to be associated with a poor prognosis in multivariate analysis of overall (relative risk 2.8; P=0.050) and disease-free (relative risk 2.3; P=0.031) survival. Cyr61 and CTGF are inversely expressed in BOTs and IOCs, and loss of CTGF independently indicates poor prognosis in IOCs.

CCN1 promotes tumorigenicity through Rac1/Akt/NF-κB signaling pathway in pancreatic cancer

Aberrant CCN1 expression has been reported to play an important role in the tumor development. However, the pattern and the role of CCN1 in pancreatic cancer remain largely unknown. Therefore, we further deciphered the role CCN1 played in pancreatic cancer. We first evaluated the CCN1 expression in human pancreatic cancer tissues and pancreatic cancer cells. Then we forced expression and silenced CCN1 expression in pancreatic cancer cell lines MIA PaCa2 and PANC-1 respectively, using lentivirus vectors. We characterized the stable cells in vitro and in vivo using a nude mouse xenograft model. In this study, we found that CCN1 expression was significantly higher in cancer specimens which positively correlated with the expression level of phosphorylated Akt and p65. and poorer outcome. Moreover, our results demonstrated that CCN1 positively regulated pancreatic cell growth in vitro and in vivo and helped cancer cells resist to tumor necrosis factor alpha-induced apoptosis. Furthermore, we disclosed that activation of CCN1/ras-related c3 botulinum toxin substrate 1 (Rac1)/V-akt murine thymoma viral oncogene homolog (Akt)/nuclear factor-kappa B pathway inhibited apoptosis in pancreatic cancer cells. CCN1 is upregulated in pancreatic cancer and promotes the survival of pancreatic cancer cells. Taken together, these results indicate that CCN1 may be a potential target for pancreatic cancer therapy.

A novel anti-Cyr61 antibody inhibits breast cancer growth and metastasis in vivo

Cysteine-rich protein 61(CCN1/Cyr61) has been implicated as an important mediator in proliferation and metastasis of breast cancer, which indicated that blockage of Cyr61 might be a potent target for breast cancer treatment. However, the antitumor effect of anti-Cyr61 antibodies on breast cancer in vivo has not been reported so far. In this study, we reported the effect and likely mechanism of generated anti-human Cyr61 monoclonal antibodies (mAb) on Cyr61 high expression line MDA-MB-231, known as a highly malignant and invasive human breast cancer cell line, at aspects of proliferation and migration in vitro and in vivo. We found the mAb, denoted as 093G9, revealed inhibitory effects on MDA-MB-231 cell proliferation, migration, and invasion through downregulation of both AKT and ERK phosphorylation in vitro compared with its isotype control. 093G9 also showed significant efficacy on suppressing primary tumor growth and spontaneous lymph node metastasis in in vivo mouse model. The specific epitope recognized by 093G9 was identified to be (140)LPNLGCP(146), adjacent to the VWC domain of Cyr61 by Ph.D.-C7C phage library display system. Our study provides direct evidence that Cyr61 can be a potent therapeutic target for patients who bear high Cyr61 expression breast cancer. Furthermore, the mAb, 093G9 developed in our laboratory, has shown a promising therapeutic characteristic in breast cancer.

Extracellular matrix protein CCN1 limits oncolytic efficacy in glioma

Oncolytic viral therapy has been explored widely as an option for glioma treatment but its effectiveness has remained limited. Cysteine rich 61 (CCN1) is an extracellular matrix (ECM) protein elevated in cancer cells that modulates their adhesion and migration by binding cell surface receptors. In this study, we examined a hypothesized role for CCN1 in limiting the efficacy of oncolytic viral therapy for glioma, based on evidence of CCN1 induction that occurs in this setting. Strikingly, we found that exogenous CCN1 in glioma ECM orchestrated a cellular antiviral response that reduced viral replication and limited cytolytic efficacy. Gene expression profiling and real-time PCR analysis revealed a significant induction of type-I interferon responsive genes in response to CCN1 exposure. This induction was accompanied by activation of the Jak/Stat signaling pathway, consistent with induction of an innate antiviral cellular response. Both effects were mediated by the binding of CCN1 to the cell surface integrin α6β1, activating its signaling and leading to rapid secretion of interferon-α, which was essential for the innate antiviral effect. Together, our findings reveal how an integrin signaling pathway mediates activation of a type-I antiviral interferon response that can limit the efficacy of oncolytic viral therapy. Furthermore, they suggest therapeutic interventions to inhibit CCN1-integrin α6 interactions to sensitize gliomas to viral oncolysis.