U94 alters FN1 and ANGPTL4 gene expression and inhibits tumorigenesis of prostate cancer cell line PC3

Targeting PRSS23 with tipranavir induces gastric cancer stem cell apoptosis and inhibits growth of gastric cancer via the MKK3/p38 MAPK-IL24 pathway

Gastric cancer stem cells (GCSCs) contribute to the refractory features of gastric cancer (GC) and are responsible for metastasis, relapse, and drug resistance. The key factors drive GCSC function and affect the clinical outcome of GC patients remain poorly understood. PRSS23 is a novel serine protease that is significantly up-regulated in several types of cancers and cancer stem cells, and related to tumor progression and drug resistance. In this study, we investigated the role of PRSS23 in GCSCs as well as the mechanism by which PRSS23 regulated the GCSC functions. We demonstrated that PRSS23 was critical for sustaining GCSC survival. By screening a collection of human immunodeficiency virus (HIV) protease inhibitors (PIs), we identified tipranavir as a PRSS23-targeting drug, which effectively killed both GCSC and GC cell lines (its IC50 values were 4.7 and 6.4 μM in GCSC1 cells and GCSC2 cells, respectively). Administration of tipranavir (25 mg·kg-1·d-1, i.p., for 8 days) in GCSC-derived xenograft mice markedly inhibited the growth of subcutaneous GCSC tumors without apparent toxicity. In contrast, combined treatment with 5-FU plus cisplatin did not affect the tumor growth but causing significant weight loss. Furthermore, we revealed that tipranavir induced GCSC cell apoptosis by suppressing PRSS23 expression, releasing MKK3 from the PRSS23/MKK3 complex to activate p38 MAPK, and thereby activating the IL24-mediated Bax/Bak mitochondrial apoptotic pathway. In addition, tipranavir was found to kill other types of cancer cell lines and drug-resistant cell lines. Collectively, this study demonstrates that by targeting both GCSCs and GC cells, tipranavir is a promising anti-cancer drug, and the clinical development of tipranavir or other drugs specifically targeting the PRSS23/MKK3/p38MAPK-IL24 mitochondrial apoptotic pathway may offer an effective approach to combat gastric and other cancers.

"Bioinspired" Membrane-Coated Nanosystems in Cancer Theranostics: A Comprehensive Review

Achieving precise cancer theranostics necessitates the rational design of smart nanosystems that ensure high biological safety and minimize non-specific interactions with normal tissues. In this regard, "bioinspired" membrane-coated nanosystems have emerged as a promising approach, providing a versatile platform for the development of next-generation smart nanosystems. This review article presents an in-depth investigation into the potential of these nanosystems for targeted cancer theranostics, encompassing key aspects such as cell membrane sources, isolation techniques, nanoparticle core selection, approaches for coating nanoparticle cores with the cell membrane, and characterization methods. Moreover, this review underscores strategies employed to enhance the multi-functionality of these nanosystems, including lipid insertion, membrane hybridization, metabolic engineering, and genetic modification. Additionally, the applications of these bioinspired nanosystems in cancer diagnosis and therapeutics are discussed, along with the recent advances in this field. Through a comprehensive exploration of membrane-coated nanosystems, this review provides valuable insights into their potential for precise cancer theranostics.

Viral Proteins as Emerging Cancer Therapeutics

Simple Summary

This review is focused on enlisting viral proteins from different host sources, irrespective of their origin, that may act as future cancer curatives. Unlike the viral proteins that are responsible for tumor progression, these newly emerged viral proteins function as tumor suppressors. Their ability to regulate various cell signaling mechanisms specifically in cancer cells makes them interesting candidates to explore their use in cancer therapy. The discussion about such viral components may provide new insights into cancer treatment in the absence of any adverse effects to normal cells. The study also highlights avian viral proteins as a substitute to human oncolytic viruses for their ability to evade pre-existing immunity.

Abstract

Viruses are obligatory intracellular parasites that originated millions of years ago. Viral elements cover almost half of the human genome sequence and have evolved as genetic blueprints in humans. They have existed as endosymbionts as they are largely dependent on host cell metabolism. Viral proteins are known to regulate different mechanisms in the host cells by hijacking cellular metabolism to benefit viral replication. Amicable viral proteins, on the other hand, from several viruses can participate in mediating growth retardation of cancer cells based on genetic abnormalities while sparing normal cells. These proteins exert discreet yet converging pathways to regulate events like cell cycle and apoptosis in human cancer cells. This property of viral proteins could be harnessed for their use in cancer therapy. In this review, we discuss viral proteins from different sources as potential anticancer therapeutics.

The U94 Gene of Human Herpesvirus 6: A Narrative Review of Its Role and Potential Functions

Human herpesvirus 6 (HHV-6) is a β-herpesvirus that is highly prevalent in the human population. HHV-6 comprises two recognized species (HHV-6A and HHV-6B). Despite different cell tropism and disease association, HHV-6A/B show high genome homology and harbor the conserved U94 gene, which is limited to HHV-6 and absent in all the other human herpesviruses. U94 has key functions in the virus life cycle and associated diseases, having demonstrated or putative roles in virus replication, integration, and reactivation. During natural infection, U94 elicits an immune response, and the prevalence and extent of the anti-U94 response are associated with specific diseases. Notably, U94 can entirely reproduce some virus effects at the cell level, including inhibition of cell migration, induction of cytokines and HLA-G expression, and angiogenesis inhibition, supporting a direct U94 role in the development of HHV-6-associated diseases. Moreover, specific U94 properties, such as the ability to modulate angiogenesis pathways, have been exploited to counteract cancer development. Here, we review the information available on this key HHV-6 gene, highlighting its potential uses.

ANGPTL4 overexpression is associated with progression and poor prognosis in breast cancer

The aim of the present study was to analyze the expression levels of angiopoietin-like 4 (ANGPTL4) in breast cancer to investigate the association between ANGPTL4 and breast cancer. Immunohistochemistry was performed on formalin-fixed paraffin-embedded tissues, including 205 invasive ductal carcinoma (IDC) of no special type, 40 normal breast, 40 atypical ductal hyperplasia (ADH) and 40 ductal carcinomas in situ (DCIS) tissues. The non-parametric Kruskal-Wallis test was used to evaluate the differential expression of ANGPTL4 and clinicopathological parameters in breast cancer. Kaplan-Meier analysis and Cox regression analysis were used to evaluate the association between the expression levels of ANGPTL4 and the prognosis of breast cancer. The results revealed that ANGPTL4 expression was higher in IDC (63.4%; 130/205) compared with in normal breast tissues (17.5%; 7/40), ADH (30%; 12/40) and DCIS (37.5%; 15/40). The clinical significance of ANGPTL4 expression was analyzed in a total of 205 IDC tissues, and high expression levels of ANGPTL4 were positively associated with pathological stage (P<0.001), tumor size (P<0.001), histological grade (P<0.001), lymph node metastasis (P<0.001), distant metastasis (P<0.001) and local recurrence (P<0.001). Kaplan-Meier analysis revealed that patients with high ANGPTL4 expression had a shorter overall survival (OS; P<0.001) and disease-free survival (DFS; P<0.001) compared with patients with low ANGPTL4 expression. Multivariate Cox regression analysis revealed that ANGPTL4 was an independent prognostic factor for breast cancer OS (P=0.034) and DFS (P=0.011). The results of the present study demonstrated that ANGPLT4 was associated with malignant progression and poor prognosis of breast cancer, suggesting that ANGPLT4 may be a novel therapeutic target for breast cancer.

Identification of novel oncogenic events occurring early in prostate carcinogenesis using purified autologous malignant and non-malignant prostate epithelial cells

OBJECTIVE

To interrogate enriched prostate cancer cells and autologous non-malignant prostate epithelial cells from men with localized prostate cancer, in order to identify early oncogenic pathways.

PATIENTS AND METHODS

We collected malignant and matched non-malignant prostatectomy samples from men with adenocarcinoma involving two or more contiguous areas in only one lobe of the prostate. Tissue samples from both lobes were subjected to digestion and single-cell suspensions were prepared. Epithelial cell adhesion molecule-positive cells from cancerous and contralateral non-malignant (control) samples were isolated using magnetic beads, ensuring uniform populations were obtained for each donor. Unbiased RNA sequencing analysis was used to measure gene expression and for detection of transcribed mutations or splice variants that were over- or under-represented in malignant prostate epithelial cells relative to autologous control prostate epithelial cells.

RESULTS

From five patient samples we identified 17 genes that were altered in prostate cancer epithelial cells, with 82% of genes being downregulated. Three genes, TDRD1, ANGTL4, and CLDN3, were consistently upregulated in malignant tissue. Malignant cells from three of the five patients showed evidence of upregulated ERG signalling, however, only one of these contained a TMPRSS2-ERG rearrangement. We did not identify mutations, gene rearrangements, or splice variants that were consistent amongst the patients.

CONCLUSIONS

Events occurring early in prostate cancer oncogenesis in these samples were characterized by a predominant downregulation of gene expression along with upregulation of TDRD1, ANGTL4 and CLDN3. No consistent mutations or splice variants were observed, but upregulation of ERG signalling was seen both in the presence and absence of the classic TMPRSS2-ERG rearrangement.

Comprehensive Analysis of Therapy-Related Messenger RNAs and Long Noncoding RNAs as Novel Biomarkers for Advanced Colorectal Cancer

Colorectal cancer (CRC) is one of the most common types of human cancers. However, the mechanisms underlying CRC progression remained elusive. This study identified differently expressed messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs), and small nucleolar RNAs (snoRNAs) between pre-therapeutic biopsies and post-therapeutic resections of locally advanced CRC by analyzing a public dataset, GSE94104. We identified 427 dysregulated mRNAs, 4 dysregulated lncRNAs, and 19 dysregulated snoRNAs between pre- and post-therapeutic locally advanced CRC samples. By constructing a protein–protein interaction network and co-expressing networks, we identified 10 key mRNAs, 4 key lncRNAs, and 7 key snoRNAs. Bioinformatics analysis showed therapy-related mRNAs were associated with nucleosome assembly, chromatin silencing at recombinant DNA, negative regulation of gene expression, and DNA replication. Therapy-related lncRNAs were associated with cell adhesion, extracellular matrix organization, angiogenesis, and sister chromatid cohesion. In addition, therapy-related snoRNAs were associated with DNA replication, nucleosome assembly, and telomere organization. We thought this study provided useful information for identifying novel biomarkers for CRC.

Interaction of tumor cells and astrocytes promotes breast cancer brain metastases through TGF-β2/ANGPTL4 axes

Metastatic outcomes depend on the interactions of metastatic cells with a specific organ microenvironment. Our previous studies have shown that triple-negative breast cancer (TNBC) MDA-MB-231 cells passaged in astrocyte-conditioned medium (ACM) show proclivity to form brain metastases, but the underlying mechanism is unknown. The combination of microarray analysis, qPCR, and ELISA assay were carried out to demonstrate the ACM-induced expression of angiopoietin-like 4 (ANGPTL4) in TNBC cells. A stable ANGPTL4-knockdown MDA-MB-231 cell line was generated by ANGPTL4 short-hairpin RNA (shRNA) and inoculated into mice via left ventricular injection to evaluate the role of ANGPTL4 in brain metastasis formation. The approaches of siRNA, neutralizing antibodies, inhibitors, and immunoprecipitation were used to demonstrate the involved signaling molecules. We first found that ACM-conditioned TNBC cells upregulated the expression of ANGPTL4, a secreted glycoprotein whose effect on tumor progression is known to be tumor microenvironment- and tumor-type dependent. Knockdown of ANGPTL4 in TNBC MDA-MB-231 cells with shRNA decreased ACM-induced tumor cell metastatic growth in the brain and attributed to survival in a mouse model. Furthermore, we identified that astrocytes produced transforming growth factor-beta 2 (TGF-β2), which in part is responsible for upregulation of ANGPTL4 expression in TNBC through induction of SMAD signaling. Moreover, we identified that tumor cells communicate with astrocytes, where tumor cell-derived interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) increased the expression of TGF-β2 in astrocytes. Collectively, these findings indicate that the invading TNBC cells interact with astrocytes in the brain microenvironment that facilitates brain metastases of TNBC cells through a TGF-β2/ANGPTL4 axis. This provides groundwork to target ANGPTL4 as a treatment for breast cancer brain metastases.

Inhibition of DNA Repair Mechanisms and Induction of Apoptosis in Triple Negative Breast Cancer Cells Expressing the Human Herpesvirus 6 U94

Triple-negative breast cancer (TNBC) accounts for 15–20% of all breast cancers. In spite of initial good response to chemotherapy, the prognosis of TNBC remains poor and no effective specific targeted therapy is readily available. Recently, we demonstrated the ability of U94, the latency gene of human herpes virus 6 (HHV-6), to interfere with proliferation and with crucial steps of the metastatic cascade by using MDA-MB 231 TNBC breast cancer cell line. U94 expression was also associated with a partial mesenchymal-to-epithelial transition (MET) of cells, which displayed a less aggressive phenotype. In this study, we show the ability of U94 to exert its anticancer activity on three different TNBC cell lines by inhibiting DNA damage repair genes, cell cycle and eventually leading to cell death following activation of the intrinsic apoptotic pathway. Interestingly, we found that U94 acted synergistically with DNA-damaging drugs. Overall, we provide evidence that U94 is able to combat tumor cells with different mechanisms, thus attesting for the great potential of this molecule as a multi-target drug in cancer therapy.

PRSS23 knockdown inhibits gastric tumorigenesis through EIF2 signaling

PRSS23 is a newly discovered serine protease that has been associated with tumor progression in various types of cancers. Our previous study showed PRSS23 is down-regulated obviously in Hedgehog pathway blocked gastric cancer cells. However, the correlation between PRSS23 and tumor progression of gastric cancer remains unclear. Here, the role and mechanism of PRSS23 in tumor progression of gastric cancer were determined. PRSS23 protein levels were significantly increased in gastric cancer tissues compared with the paired adjacent normal gastric mucosa tissues. The high expression of PRSS23 correlated strongly with both poor differentiated histology and cancer region of sinus ventriculi. Gastric cancer patients with low PRSS23 expression displayed a better prognosis. In gastric cancer cells, PRSS23 knockdown inhibited cell proliferation and induced apoptosis. In xenograft tumor model, PRSS23 knockdown led to dramatic decreases of the average tumor volume and the average tumor weight. In addition, PRSS23 knockdown suppressed gastric cancer growth through inhibiting EIF2 signaling using gene expression microarray analysis. Taken together, our results suggest PRSS23 is highly associated with human gastric tumorigenesis and progression. PRSS23 knockdown could suppress tumor growth of gastric cancer in vitro and in vivo through inhibiting EIF2 signaling, and EIF4E maybe a potential target of PRSS23. PRSS23 could serve as a potential target for gastric cancer therapy, and also a biomarker for the prediction of prognosis of gastric cancer.

The Roles of ANGPTL Families in Cancer Progression

Angiopoietins play important roles in angiogenesis and the maintenance of hematopoietic stem cells. Angiopoietin-like proteins (ANGPTLs) are identified as proteins structurally similar to angiopoietins, and the ANGPTL family now consists of eight members. ANGPTLs are secretary proteins, and some ANGPTLs are not only angiogenic factors but also proteins with multiple functions such as glucose metabolism, lipid metabolism, redox regulation and chronic inflammation. Chronic inflammation is one of the key factors in carcinogenesis and cancer growth, proliferation, invasion and metastasis. ANGPTL 2, 3, 4, 6 and 7 are pro-inflammatory factors and regulate cancer progression, while ANGPTL1 inhibits tumor angiogenesis and metastasis. In this review, we describe the roles of ANGPTLs in cancer progression and discuss the possibility of disturbing the progression of cancer by regulating ANGPTLs expression.

U94/rep of human herpesvirus 6 inhibits proliferation, invasion, and angiogenesis of glioma

Purpose

We previously found the involvement of human herpesvirus 6 (HHV-6) infection in the pathogenesis of glioma. U94/rep, encoded by HHV-6, has been identified to play a vital role in viral gene expression and latency. Recent studies have shown its inhibition of angiogenesis and tumorigenesis in endothelial cells and prostate cancer cell line PC3, respectively. Here, we aimed to investigate the role of U94/rep in the development and progression of glioma.

Patients and methods

Patients and methods

A total of 20 glioma tissues with positive HHV-6 infection were used for detection of U94/rep. MTT, soft agar, propidium iodide staining, wound healing, Transwell, and chick embryo chorioallantoic membrane assays were applied for evaluation of glioma cells’ proliferation, colony formation, cell cycle, migration, invasion, and angiogenesis, respectively.

Results

U94/rep transcripts could be detected in 11 out of 20 glioma tissues with positive HHV-6 infection. Furthermore, MTT and soft agar assays revealed that overexpression of U94/rep inhibited glioma cell proliferation and colony formation, which may be attributed to the cell cycle arrest at S phase induced by U94/rep. Further analysis demonstrated that U94/rep inhibited glioma cells’ migration and invasion and ex vivo angiogenesis. Reduced expression of proangiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor, and type IV collagenases, MMP-2 and MMP-9, was detected in cells overexpressing U94/rep. These decreased factors may undermine glioma cell migration, invasion, and angiogenesis.

Conclusion

Our results demonstrated that U94/rep could inhibit malignant phenotypes of glioma cells, indicating that it is a potential target for therapeutic intervention.

MEIS1 and MEIS2 Expression and Prostate Cancer Progression: A Role For HOXB13 Binding Partners in Metastatic Disease

Purpose: Germline mutations within the MEIS-interaction domain of HOXB13 have implicated a critical function for MEIS-HOX interactions in prostate cancer etiology and progression. The functional and predictive role of changes in MEIS expression within prostate tumor progression, however, remain largely unexplored.Experimental Design: Here we utilize RNA expression datasets, annotated tissue microarrays, and cell-based functional assays to investigate the role of MEIS1 and MEIS2 in prostate cancer and metastatic progression.Results: These analyses demonstrate a stepwise decrease in the expression of both MEIS1 and MEIS2 from benign epithelia, to primary tumor, to metastatic tissues. Positive expression of MEIS proteins in primary tumors, however, is associated with a lower hazard of clinical metastasis (HR = 0.28) after multivariable analysis. Pathway and gene set enrichment analyses identified MEIS-associated networks involved in cMYC signaling, cellular proliferation, motility, and local tumor environment. Depletion of MEIS1 and MEIS2 resulted in increased tumor growth over time in vivo, and decreased MEIS expression in both patient-derived tumors and MEIS-depleted cell lines was associated with increased expression of the protumorigenic genes cMYC and CD142, and decreased expression of AXIN2, FN1, ROCK1, SERPINE2, SNAI2, and TGFβ2.Conclusions: These data implicate a functional role for MEIS proteins in regulating cancer progression, and support a hypothesis whereby tumor expression of MEIS1 and MEIS2 expression confers a more indolent prostate cancer phenotype, with a decreased propensity for metastatic progression. Clin Cancer Res; 24(15); 3668-80. ©2018 AACR.

Angiopoietin-Like Proteins in Angiogenesis, Inflammation and Cancer

Altered expression of secreted factors by tumor cells or cells of the tumor microenvironment is a key event in cancer development and progression. In the last decade, emerging evidences supported the autocrine and paracrine activity of the members of the Angiopoietin-like (ANGPTL) protein family in angiogenesis, inflammation and in the regulation of different steps of carcinogenesis and metastasis development. Thus, ANGPTL proteins become attractive either as prognostic or predictive biomarkers, or as novel target for cancer treatment. Here, we outline the current knowledge about the functions of the ANGPTL proteins in angiogenesis, cancer progression and metastasis. Moreover, we discuss the most recent evidences sustaining their role as prognostic or predictive biomarkers for cancer therapy. Although the role of ANGPTL proteins in cancer has not been fully elucidated, increasing evidence suggest their key effects in the proliferative and invasive properties of cancer cells. Moreover, given the common overexpression of ANGPTL proteins in several aggressive solid tumors, and their role in tumor cells and cells of the tumor microenvironment, the field of research about ANGPTL proteins network may highlight new potential targets for the development of future therapeutic strategies.

Angiopoietin-like protein 4 potentiates DATS-induced inhibition of proliferation, migration, and invasion of bladder cancer EJ cells; involvement of G2/M-phase cell cycle arrest, signaling pathways, and transcription factors-mediated MMP-9 expression

Background: Diallyl trisulfide (DATS), a bioactive sulfur compound in garlic, has been highlighted due to its strong anti-carcinogenic activity.

Objective: The current study investigated the molecular mechanism of garlic-derived DATS in cancer cells. Additionally, we explored possible molecular markers to monitoring clinical responses to DATS-based chemotherapy.

Design: EJ bladder carcinoma cells were treated with different concentration of DATS. Molecular changes including differentially expressed genes in EJ cells were examined using immunoblot, FACS cell cycle analysis, migration and invasion assays, electrophoresis mobility shift assay (EMSA), microarray, and bioinformatics analysis.

Results: DATS inhibited EJ cell growth via G₂/M-phase cell cycle arrest. ATM-CHK2-Cdc25c-p21WAF1-Cdc2 signaling cascade, MAPKs, and AKT were associated with the DATS-mediated growth inhibition of EJ cells. DATS-induced inhibition of migration and invasion was correlated with down-regulated MMP-9 via reduced activation of AP-1, Sp-1, and NF-κB. Through microarray gene expression analysis, ANGPTL4, PLCXD1, and MMP3 were identified as candidates of molecular targets of DATS. Introduction of each gene to EJ cells revealed that ANGPTL4 was associated with the DATS-induced inhibition of cell growth, migration, and invasion.

Conclusions: ANGPTL4 regulates DATS-mediated inhibition of proliferation, migration, and invasion of EJ cells, and thus, has potential as a prognostic marker for bladder cancer patients.

Elevation of MiR-9-3p suppresses the epithelial-mesenchymal transition of nasopharyngeal carcinoma cells via down-regulating FN1, ITGB1 and ITGAV

MicroRNAs had been proved to be pivotal regulators in nasopharyngeal carcinoma (NPC) by regulating a large amount of genes' expression. In our research, we aim to explore the functions of miR-9-3p on the metastases of NPC and figure out the potential mechanisms. First, we revealed downregulation of miR-9-3p and upregulation of fibronectin 1 (FN1), β1 integrin (ITGB1) and α5 integrin (ITGAV) expression in NPC tissues and cells compared with the normal using RNA-seq analysis, RT-qPCR, western blot and immunohistochemistry. By transfection of miR-9-3p mimics in CNE-1, CNE-2 and HONE-1 cells, we confirmed tumor-suppressing roles of miR-9-3p via suppressing EMT process by MTT, wound scratch, transwell assay and western blot. After constructing luciferase reporting plasmids and transient transfection in HEK 293T cells, we proved that FN1, ITGB1 and ITGAV were all targets of miR-9-3p. Then we manipulated the expression of miR-9-3p, FN1, ITGB1 and ITGAV in HONE-1 cells, verifying the tumor-promoting effect of FN1, ITGB1 and ITGAV on cell proliferation and metastases via facilitating EMT process of cells. Additionally, these functions of FN1, ITGB1 and ITGAV could be efficiently abrogated by overexpression of miR-9-3p. Taken together, we demonstrated that elevation of miR-9-3p suppresses the proliferation and metastases of NPC via downregulating FN1, ITGB1, ITGAV and inhibiting the EMT process, which provided a series of therapeutic targets for the treatment of NPC.

Hypoxia-induced angiopoietin-like protein 4 as a clinical biomarker and treatment target for human prostate cancer

Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional protein, playing roles in glucose and lipid metabolism, inflammation, angiogenesis, and tumorigenesis. Recent research suggests that ANGPTL4 is induced by hypoxia and is a useful diagnostic or prognostic marker for various cancers. However, it remains unclear whether ANGPTL4 expression influences prostate cancer. Here we examined the biological and clinical relevance of ANGPTL4 expression in prostate cancer. Firstly we examined ANGPTL4 expression in the prostate cancer cell lines LNCaP and LNCaP/CH incubated at 1% O2 for at least 6 months. We compared cellular proliferation, migration, and ANGPTL4 secretion in a culture medium between these cell lines. In addition, we investigated the effect of various concentrations of recombinant ANGPTL4 protein (rANGPTL4) on cellular proliferation and intracellular signaling pathways. Moreover, we used ANGPTL4 knockdown by RNA interference to investigate the influence of ANGPTL4 expression on these cell lines. Finally, we investigated the correlation between ANGPTL4 expression in prostate cancer specimens and clinicopathological parameters using immunohistochemistry. Our data suggested that the expression of ANGPTL4 in hypoxic conditions was 14.4-fold higher than that in normoxic condition. ANGPTL4 secretion in the culture medium increased 7.0-fold. In addition, rANGPTL4 increased cellular proliferation 1.72-fold via Akt activation. Moreover, ANGPTL4 knockdown decreased cell growth and its secretion by 25.7 and 41.4%, respectively, compared with the control. A multivariate analysis showed that positive ANGPTL4 expression in the resected specimens was an independent prognostic indicator of biochemical recurrence (P=0.03, hazard ratio = 2.02). Our results show that ANGPTL4 is induced by hypoxia and promotes cancer progression via the activated PI3K/Akt pathway. Moreover, ANGPTL4 can be used as a prognostic marker for prostate cancer patients undergoing radical prostatectomy.

IQGAP1‑siRNA inhibits proliferation and metastasis of U251 and U373 glioma cell lines

IQ motif containing GTPase activating protein 1 (IQGAP1) is a scaffold protein, which is aberrantly expressed in several tumor types and is closely associated with the development, metastasis and prognosis of cancer. Several studies have demonstrated that IQGAP1 has broad prospects in the basic and clinical research of tumors. The present study aimed to explore the effects of IQGAP1‑small interfering (si) NA on the proliferation and metastasis of U251 and U373 glioma cell lines, which markedly expressed IQGAP1. The human glioma cell lines (U251 and U373) were transfected with siRNA and transfection efficacy was confirmed by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. Cell proliferation was detected using the Cell Counting kit‑8, and cell metastasis capabilities were detected using cell adhesion, migration and invasion assays. In addition, the expression levels of several tumor‑associated genes were determined by RT‑qPCR and western blotting. The results indicated that IQGAP1 was expressed at higher levels in glioma tissues compared with in normal brain tissues. IQGAP1‑siRNA significantly inhibited cell proliferation, and cell adhesion, migration and invasion. Furthermore, the expression levels of matrix metalloproteinase (MMP)2, Snail, MMP9, fibronectin 1 and Twist were suppressed, and E‑cadherin was upregulated in response to siRNA‑IQGAP1. The present study identified the function of IQGAP1 in glioma cell biology, and indicated that it may be considered a novel target for glioma treatment.

Microarray based analysis of gene regulation by mesenchymal stem cells in breast cancer

Breast cancer is one of the most common malignant tumors with a high case-fatality rate among women. The present study aimed to investigate the effects of mesenchymal stem cells (MSCs) on breast cancer by exploring the potential underlying molecular mechanisms. The expression profile of GSE43306, which refers to MDA-MB-231 cells with or without a 1:1 ratio of MSCs, was downloaded from Gene Expression Omnibus database for differentially expressed gene (DEG) screening. The Database for Annotation, Visualization and Integrated Discovery was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs. The protein-protein interactional (PPI) network of DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins. The data was subsequently analyzed using molecular complex detection for sub-network mining of modules. Finally, DEGs in modules were analyzed using GO and KEGG pathway enrichment analyses. A total of 291 DEGs including 193 upregulated and 98 downregulated DEGs were obtained. Upregulated DEGs were primarily enriched in pathways including response to wounding (P=5.92×10^-7), inflammatory response (P=5.92×10^-4) and defense response (P=1.20×10^-2), whereas downregulated DEGs were enriched in pathways including the cell cycle (P=7.13×10^-4), mitotic cell cycle (P=6.81×10^-3) and M phase (P=1.72 ×10^-2). The PPI network, which contained 156 nodes and 289 edges, was constructed, and Fos was the hub node with the degree of 29. A total of 3 modules were mined from the PPI network. In total, 14 DEGs in module A were primarily enriched in GO terms, including response to wounding (P=4.77×10^-6), wounding healing (P=6.25×10^-7) and coagulation (P=1.13 ×10^-7), and these DEGs were also enriched in 1 KEGG pathway (complement and coagulation cascades; P=0.0036). Therefore, MSCs were demonstrated to exhibit potentially beneficial effects for breast cancer therapy. In addition, the screened DEGs, particularly in PPI network modules, including FN1, CD44, NGF, SERPINE1 and CCNA2, may be the potential target genes of MSC therapy for breast cancer.

Modulation of paracrine signaling by CD9 positive small extracellular vesicles mediates cellular growth of androgen deprived prostate cancer

Proliferation and maintenance of both normal and prostate cancer (PCa) cells is highly regulated by steroid hormones, particularly androgens, and the extracellular environment. Herein, we identify the secretion of CD9 positive extracellular vesicles (EV) by LNCaP and DUCaP PCa cells in response to dihydrotestosterone (DHT) and use nano-LC–MS/MS to identify the proteins present in these EV. Subsequent bioinformatic and pathway analyses of the mass spectrometry data identified pathologically relevant pathways that may be altered by EV contents. Western blot and CD9 EV TR-FIA assay confirmed a specific increase in the amount of CD9 positive EV in DHT-treated LNCaP and DUCaP cells and treatment of cells with EV enriched with CD9 after DHT exposure can induce proliferation in androgen-deprived conditions. siRNA knockdown of endogenous CD9 in LNCaPs reduced cellular proliferation and expression of AR and prostate specific antigen (PSA) however knockdown of AR did not alter CD9 expression, also implicating CD9 as an upstream regulator of AR. Moreover CD9 positive EV were also found to be significantly higher in plasma from prostate cancer patients in comparison with benign prostatic hyperplasia patients. We conclude that CD9 positive EV are involved in mediating paracrine signalling and contributing toward prostate cancer progression.

Regulation and clinical significance of the hypoxia-induced expression of ANGPTL4 in gastric cancer

Solid tumors are often exposed to hypoxia. Hypoxia inducible factor (HIF)-1α upregulates numerous target genes associated with the malignant behavior of hypoxic cancer cells. A member of the angiopoietin family, angiopoietin-like protein 4 (ANGPTL4) is a hypoxia-inducible gene. The present study aimed to clarify whether ANGPTL4 is regulated by HIF-1α in gastric cancer cells. The study also assessed whether ANGPTL4 expression is associated with clinicopathological factors or HIF-1α expression in gastric cancer tissues. Hypoxia-induced ANGPTL4 expression was quantitatively analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in 10 gastric cancer cell lines. RT-qPCR was further employed to investigate the HIF-1α dependency of ANGPTL4 expression using HIF-1α-knockdown transfectant 58As9-KD and control 58As9-SC gastric cancer cells. The HIF-1α and ANGPTL4 expression levels were immunohistochemically analyzed in 170 gastric cancer tissue specimens and were assessed for any correlations with the clinicopathological factors and/or patient survival. Subsequently, hypoxia-induced ANGPTL4 expression was observed in 7 out of 10 gastric cancer cell lines. The hypoxic induction of ANGPTL4 was almost preserved in the 58As9-KD cells compared with that observed in the 58As9-SC cells, while the induction of known HIF-1α target gene, carbonic anhydrase 9, was completely suppressed in the 58As9-KD cells. In the gastric cancer tissues, ANGPTL4 expression was inversely correlated with the tumor depth, whereas HIF-1α expression was positively correlated with venous invasion. A survival analysis revealed that the expression of ANGPTL4 was significantly correlated with a longer survival time, whereas that of HIF-1α was correlated with a shorter survival time. In conclusion, the present findings indicate that hypoxia-induced ANGPTL4 expression is independent of HIF-1α in hypoxic gastric cancer cells. ANGPTL4 may be a favorable marker for predicting a long survival time, whereas HIF-1α predicts a poor prognosis, in gastric cancer patients. The hypoxic environment independently induces ANGPTL4 and HIF-1α, which are believed to exhibit adverse effects on tumor progression.

SP1 and USF differentially regulate ADAMTS1 gene expression under normoxic and hypoxic conditions in hepatoma cells

ADAM metallopeptidase with thrombospondin type I motif, 1 (ADAMTS1) that has both antiangiogenic and aggrecanase activity was dysregulated in many pathophysiologic circumstances. However, there is limited information available on the transcriptional regulation of ADAMTS1 gene. Therefore, this study mainly aimed to identify regulatory regions important for the regulation of ADAMTS1 gene under normoxic and hypoxic conditions in human hepatoma cells (HEP3B). Cultured HEP3B cells were exposed to normal oxygen condition, and Cobalt chloride (CoCl2) induced the hypoxic condition, which is an HIF-1 inducer. The cocl2-induced hypoxic condition led to the induced ADAMTS1 mRNA and protein expression in Hepatoma cells. Differential regulation of SP1 and USF transcription factors on ADAMTS1 gene expression was determined by transcriptional activity, mRNA and protein level of ADAMTS1 gene. Ectopic expression of SP1 and USF transcription factors resulted in the decrease in ADAMTS1 transcriptional activity of all promoter constructs consistent with mRNA and protein level in normoxic condition. However, overexpression of SP1 and USF led to the increase of ADAMTS1 gene expressions at mRNA and protein level in hypoxic condition. On the other hand, C/EBPα transcription factor didn't show any statistically significant effect on ADAMTS1 gene expression at mRNA, protein and transcriptional level under normoxic and hypoxic condition.

Cancer as a Proinflammatory Environment: Metastasis and Cachexia

The development of the syndrome of cancer cachexia and that of metastasis are related with a poor prognostic for cancer patients. They are considered multifactorial processes associated with a proinflammatory environment, to which tumour microenvironment and other tissues from the tumour bearing individuals contribute. The aim of the present review is to address the role of ghrelin, myostatin, leptin, HIF, IL-6, TNF-α, and ANGPTL-4 in the regulation of energy balance, tumour development, and tumoural cell invasion. Hypoxia induced factor plays a prominent role in tumour macro- and microenvironment, by modulating the release of proinflammatory cytokines.

Angiopoietin-like 4 enhances metastasis and inhibits apoptosis via inducing bone morphogenetic protein 7 in colorectal cancer cells

Angiopoietin-like 4 (ANGPTL4), a secretory glycoprotein, plays an important role in cancer metastasis. In the present study, we aim to investigate the roles and mechanisms of ANGPTL4 in the regulation of colorectal cancer metastasis. We found that expression level of ANGPTL4 was increased in colorectal cancer tissues, compared with that in normal tissues. Moreover, liver metastasis was significantly associated with higher expression of ANGPTL4. In vitro studies further showed that overexpression of ANGPTL4 enhanced cell migration, invasion and inhibited apoptosis. At the molecular level, ANGPTL4 overexpression resulted in an up-regulation of bone morphogenetic protein 7 (BMP7). Indeed, knockdown of BMP7 by small interfering RNA (siRNA) oligos reversed the roles of ANGPTL4 overexpression in HCT116 cells. Finally, in vivo studies further confirmed the metastatic roles of ANGPTL4 by inducing BMP7. Therefore, our study demonstrated that ANGPTL4 might promote metastasis and might inhibit apoptosis of colorectal cancer cells by up-regulation of BMP7.

Expression array analysis of the hepatocyte growth factor invasive program

Signaling by human hepatocyte growth factor (hHGF) via its cell surface receptor (MET) drives mitogenesis, motogenesis and morphogenesis in a wide spectrum of target cell types and embryologic, developmental and homeostatic contexts. Oncogenic pathway activation also contributes to tumorigenesis and cancer progression, including tumor angiogenesis and metastasis, in several prevalent malignancies. The HGF gene encodes full-length hHGF and two truncated isoforms known as NK1 and NK2. NK1 induces all three HGF activities at modestly reduced potency, whereas NK2 stimulates only motogenesis and enhances HGF-driven tumor metastasis in transgenic mice. Prior studies have shown that mouse HGF (mHGF) also binds with high affinity to human MET. Here we show that, like NK2, mHGF stimulates cell motility, invasion and spontaneous metastasis of PC3M human prostate adenocarcinoma cells in mice through human MET. To identify target genes and signaling pathways associated with motogenic and metastatic HGF signaling, i.e., the HGF invasive program, gene expression profiling was performed using PC3M cells treated with hHGF, NK2 or mHGF. Results obtained using Ingenuity Pathway Analysis software showed significant overlap with networks and pathways involved in cell movement and metastasis. Interrogating The Cancer Genome Atlas project also identified a subset of 23 gene expression changes in PC3M with a strong tendency for co-occurrence in prostate cancer patients that were associated with significantly decreased disease-free survival.

ANGPTL4 regulates the metastatic potential of oral squamous cell carcinoma

Lymph node metastasis is a major factor for poor prognosis in oral squamous cell carcinoma (OSCC). However, the molecular mechanisms of lymph node metastasis are unclear. We determined that angiopoietin-like protein 4 (ANGPTL4) mRNA and protein expression were increased in OSCC cells established from the primary site in metastatic cases. In addition, ANGPTL4 expression in biopsy specimens was correlated with the presence of lymph node metastasis. Therefore, our initial findings suggest that OSCC cells expressing ANGPTL4 may possess metastatic ability. Furthermore, cell culture supernatants from OSCC cells that metastasized to the lymph node contain ANGPTL4 and promote invasive ability. These findings suggest that secreted ANGPTL4 may affect the invasive ability of OSCC. Moreover, the rates of positive ANGPTL4 expression at the primary site were significantly higher in the lymph node metastasis group. These results demonstrate that ANGPTL4 contributes to OSCC metastasis by stimulating cell invasion. Therefore, ANGPTL4 is a potential therapeutic target for preventing cancer metastasis.

Effect of preculture and loading on expression of matrix molecules, matrix metalloproteinases, and cytokines by expanded osteoarthritic chondrocytes

OBJECTIVE

One of the pathologic changes that occurs during osteoarthritis (OA) is the degeneration of the pericellular matrix (PCM). Since the PCM is likely to be involved in mechanotransduction, this study was undertaken to investigate the effects of PCM-like matrix accumulation in zonal OA chondrocytes and their influence on chondrocyte response to compression.

METHODS

Superficial and middle/deep zone chondrocytes from macroscopically normal cartilage of OA knees were expanded and encapsulated in alginate gels. The effects of compression (short-term or long-term) and preculture on chondrocyte expression of various matrix molecules, cytokines, and matrix metalloproteinases (MMPs) were assessed. Additionally, nonexpanded chondrocytes were encapsulated in alginate and cultured in the presence or absence of transforming growth factor β1 (TGFβ1) and dexamethasone and analyzed following short-term compression experiments.

RESULTS

Expanded OA chondrocytes (superficial and middle/deep zone) that were precultured for 2 weeks under free-swelling conditions prior to dynamic compression responded more sensitively to loading and had increased matrix accumulation, increased interleukin-1β (IL-1β) and IL-4 levels, and decreased levels of MMP-2 (in the middle/deep zone) compared to the nonloaded controls. Compression also decreased MMP-3 and MMP-13 levels even without preculture. Nonexpanded chondrocytes did not respond to compression, but differences in gene expression were found depending on the zone of harvest, time in culture, and medium composition.

CONCLUSION

Our findings demonstrate that with predeposited PCM-like matrix, compressive stimulation can enhance matrix protein accumulation in expanded OA chondrocytes. Investigations into how PCM or other matrix components differentially affect this balance under mechanical loading may provide invaluable insight into OA pathogenesis and the use of expanded cells in tissue engineering and regenerative medicine-based applications.

Insights into significant pathways and gene interaction networks underlying breast cancer cell line MCF-7 treated with 17β-estradiol (E2)

OBJECTIVE

Estrogens are known to regulate the proliferation of breast cancer cells and to alter their cytoarchitectural and phenotypic properties, but the gene networks and pathways by which estrogenic hormones regulate these events are only partially understood.

METHODS

We used global gene expression profiling by Affymetrix GeneChip microarray analysis, with KEGG pathway enrichment, PPI network construction, module analysis and text mining methods to identify patterns and time courses of genes that are either stimulated or inhibited by estradiol (E2) in estrogen receptor (ER)-positive MCF-7 human breast cancer cells.

RESULTS

Of the genes queried on the Affymetrix Human Genome U133 plus 2.0 microarray, we identified 628 (12h), 852 (24h) and 880 (48 h) differentially expressed genes (DEGs) that showed a robust pattern of regulation by E2. From pathway enrichment analysis, we found out the changes of metabolic pathways of E2 treated samples at each time point. At 12h time point, the changes of metabolic pathways were mainly focused on pathways in cancer, focal adhesion, and chemokine signaling pathway. At 24h time point, the changes were mainly enriched in neuroactive ligand-receptor interaction, cytokine-cytokine receptor interaction and calcium signaling pathway. At 48 h time point, the significant pathways were pathways in cancer, regulation of actin cytoskeleton, cell adhesion molecules (CAMs), axon guidance and ErbB signaling pathway. Of interest, our PPI network analysis and module analysis found that E2 treatment induced enhancement of PRSS23 at the three time points and PRSS23 was in the central position of each module. Text mining results showed that the important genes of DEGs have relationship with signal pathways, such as ERbB pathway (AREG), Wnt pathway (NDP), MAPK pathway (NTRK3, TH), IP3 pathway (TRA@) and some transcript factors (TCF4, MAF).

CONCLUSIONS

Our studies highlight the diverse gene networks and metabolic and cell regulatory pathways through which E2 operates to achieve its widespread effects on breast cancer cells.

The metalloproteinase ADAMTS1: a comprehensive review of its role in tumorigenic and metastatic pathways

As it was first characterized in 1997, the ADAMTS (A Disintegrin and Metalloprotease with ThromboSpondin motifs) metalloprotease family has been associated with many physiological and pathological conditions. Of the 19 proteases belonging to this family, considerable attention has been devoted to the role of its first member ADAMTS1 in cancer. Elevated ADAMTS1 promotes pro-tumorigenic changes such as increased tumor cell proliferation, inhibited apoptosis and altered vascularization. Importantly, it facilitates significant peritumoral remodeling of the extracellular matrix environment to promote tumor progression and metastasis. However, discrepancy exists, as several studies also depict ADAMTS1 as a tumor suppressor. This article reviews the current understanding of ADAMTS1 regulation and the consequence of its dysregulation in primary cancer and ADAMTS1-mediated pathways of cancer progression and metastasis.

Early response of gene expression in the distal intestine of Atlantic salmon (Salmo salar L.) during the development of soybean meal induced enteritis

Plant products in general and soybeans in particular can challenge the function and health of the intestinal tract. Salmonids develop an intestinal inflammation when fed diets containing soybean meal (SBM) and certain other legume ingredients. In the present study a 44K oligonucleotide salmonid microarray, qPCR and histology were used to investigate early response mechanisms in the distal intestine of Atlantic salmon (Salmo salar L.) during the first week of oral exposure to a diet containing 20% extracted SBM. The distal intestine transcriptome was profiled on days 1, 2, 3, 5 and 7 and compared to a control group fed fishmeal as the sole protein source. Histological evaluation of the distal intestine revealed the first signs of inflammation on day 5. The most prominent gene expression changes were seen on days 3 and 5. Up-regulation in immune-related genes was observed during the first 5 days, including GTPase IMAP family members, NF-kB-related genes and regulators of T cell and B cell function. Many functional genes involved in lipid metabolism, proteolysis, transport, metabolism and detoxification were initially up-regulated on days 1-3, possibly as an attempt by the tissue to compensate for the initiating immune response. Cell repair and extracellular matrix remodeling genes were up-regulated (heparanase, collagenase) on days 3 and 5. Down regulation of genes related to endocytosis, exocytosis, detoxification, transporters and metabolic processes from day 5 indicated initiation of dysfunction of digestive and metabolic functions that may occur as a result of inflammation or as a response to the introduction of soybean meal in the diet. This is the first study conducting transcriptomic profiling to characterize early responses during the development of SBMIE. Switching Atlantic salmon from a fishmeal to a 20% SBM diet resulted in rapid changes to the intestinal transcriptome, indicating an immune reaction with subsequent impaired epithelial barrier function and other vital intestinal functions.

Angiopoietin-like protein 4: health effects, modulating agents and structure-function relationships

Angiopoietin-like protein 4 (ANGPTL4) has been identified as a multifunctional signal protein. It is produced by a variety of tissues, and is secreted into the bloodstream in glycosylated, oligomerized, native and cleaved isoforms to modulate physiological events such as angiogenesis, cell differentiation and the crosstalk between liver, brain, adipose and muscle tissue in lipid and glucose metabolism. In addition, the expression and isoform appearance of ANGPTL4 are modified by the intestinal microbiota. With an eye on an effective strategy to improve health using ANGPTL4, we will focus on: health issues associated with ANGPTL4 expression, including obesity, Type 2 diabetes, cardiovascular diseases and cancer; several modulators of ANGPTL4 of chemical, microbiological, food and host origin; and the correlation of the specific ANGPTL4 isoforms with these modulators and their health effects.

Emerging roles of angiopoietin-like 4 in human cancer

Angiopoietin-like 4 (ANGPTL4) is best known for its role as an adipokine involved in the regulation of lipid and glucose metabolism. The characterization of ANGPTL4 as an adipokine is largely due to our limited understanding of the interaction partners of ANGPTL4 and how ANGPTL4 initiates intracellular signaling. Recent findings have revealed a critical role for ANGPTL4 in cancer growth and progression, anoikis resistance, altered redox regulation, angiogenesis, and metastasis. Emerging evidence suggests that ANGPTL4 function may be drastically altered depending on the proteolytic processing and posttranslational modifications of ANGPTL4, which may clarify several conflicting roles of ANGPTL4 in different cancers. Although the N-terminal coiled-coil region of ANGPTL4 has been largely responsible for the endocrine regulatory role in lipid metabolism, insulin sensitivity, and glucose homeostasis, it has now emerged that the COOH-terminal fibrinogen-like domain of ANGPTL4 may be a key regulator in the multifaceted signaling during cancer development. New insights into the mechanistic action of this functional domain have opened a new chapter into the possible clinical application of ANGPTL4 as a promising candidate for clinical intervention in the fight against cancer. This review summarizes our current understanding of ANGPTL4 in cancer and highlights areas that warrant further investigation. A better understanding of the underlying cellular and molecular mechanisms of ANGPTL4 will reveal novel insights into other aspects of tumorigenesis and the potential therapeutic value of ANGPTL4.

Serine protease PRSS23 is upregulated by estrogen receptor α and associated with proliferation of breast cancer cells

Serine protease PRSS23 is a newly discovered protein that has been associated with tumor progression in various types of cancers. Interestingly, PRSS23 is coexpressed with estrogen receptor α (ERα), which is a prominent biomarker and therapeutic target for human breast cancer. Estrogen signaling through ERα is also known to affect cell proliferation, apoptosis, and survival, which promotes tumorigenesis by regulating the production of numerous downstream effector proteins.In the present study, we aimed to clarify the correlation between and functional implication of ERα and PRSS23 in breast cancer. Analysis of published breast cancer microarray datasets revealed that the gene expression correlation between ERα and PRSS23 is highly significant among all ERα-associated proteases in breast cancer. We then assessed PRSS23 expression in 56 primary breast cancer biopsies and 8 cancer cell lines. The results further confirmed the coexpression of PRSS23 and ERα and provided clinicopathological significance. In vitro assays in MCF-7 breast cancer cells demonstrated that PRSS23 expression is induced by 17β-estradiol-activated ERα through an interaction with an upstream promoter region of PRSS23 gene. In addition, PRSS23 knockdown may suppress estrogen-driven cell proliferation of MCF-7 cells.Our findings imply that PRSS23 might be a critical component of estrogen-mediated cell proliferation of ERα-positive breast cancer cells. In conclusion, the present study highlights the potential for PRSS23 to be a novel therapeutic target in breast cancer research.

Leptospira santorosai Serovar Shermani detergent extract induces an increase in fibronectin production through a Toll-like receptor 2-mediated pathway

Leptospirosis can activate inflammatory responses through Toll-like receptors (TLRs) and may cause renal tubulointerstitial fibrosis characterized by the accumulation of extracellular matrix (ECM). We have previously demonstrated that Leptospira santorosai serovar Shermani detergent extract stimulates ECM accumulation in vitro. The aim of this study was to examine the mechanistic basis of these previous observations and, in particular, to examine the potential involvement of TLRs. The addition of serovar Shermani detergent extract led to an increase in fibronectin gene expression and production. Inhibition of TLR2 but not TLR4 expression abrogated serovar Shermani detergent extract-mediated increases in fibronectin production. This response was also blocked by the knockdown of the gene expression of the TLR2 downstream transducers myeloid differentiation factor 88 (MyD88) and tumor necrosis factor receptor-associated factor 6 (TRAF6). Serovar Shermani detergent extract also activated nuclear factor-κB, and its inhibition by curcumin-attenuated serovar Shermani detergent extract induced increases in fibronectin production. These effects were also mimicked by the specific TLR2 agonist, Pam(3)CsK(4), a response that was also abrogated by the knockdown of MyD88 and TRAF6. Similarly, the administration of live leptospires to cells also induced fibronectin production that was blocked by inhibition of TLR2 and MyD88 expression. In conclusion, serovar Shermani detergent extract can induce fibronectin production through the TLR2-associated cascade, providing evidence of an association between TLRs and leptospirosis-mediated ECM deposition.

ADAMTS1 alters blood vessel morphology and TSP1 levels in LNCaP and LNCaP-19 prostate tumors

Background

Decreased expression of the angiogenesis inhibitor ADAMTS1 (ADAM metallopeptidase with thrombospondin type 1 motif, 1) has previously been reported during prostate cancer progression. The aim of this study was to investigate the function of ADAMTS1 in prostate tumors.

Methods

ADAMTS1 was downregulated by shRNA technology in the human prostate cancer cell line LNCaP (androgen-dependent), originally expressing ADAMTS1, and was upregulated by transfection in its subline LNCaP-19 (androgen-independent), expressing low levels of ADAMTS1. Cells were implanted subcutaneously in nude mice and tumor growth, microvessel density (MVD), blood vessel morphology, pericyte coverage and thrombospondin 1 (TSP1) were studied in the tumor xenografts.

Results

Modified expression of ADAMTS1 resulted in altered blood vessel morphology in the tumors. Low expression levels of ADAMTS1 were associated with small diameter blood vessels both in LNCaP and LNCaP-19 tumors, while high levels of ADAMTS1 were associated with larger vessels. In addition, TSP1 levels in the tumor xenografts were inversely related to ADAMTS1 expression. MVD and pericyte coverage were not affected. Moreover, upregulation of ADAMTS1 inhibited tumor growth of LNCaP-19, as evidenced by delayed tumor establishment. In contrast, downregulation of ADAMTS1 in LNCaP resulted in reduced tumor growth rate.

Conclusions

The present study demonstrates that ADAMTS1 is an important regulatory factor of angiogenesis and tumor growth in prostate tumors, where modified ADAMTS1 expression resulted in markedly changed blood vessel morphology, possibly related to altered TSP1 levels.

Induction of ANGPTL4 expression in human airway smooth muscle cells by PMA through activation of PKC and MAPK pathways

In this study, we demonstrate that protein kinase C (PKC) activators, including phorbol-12-myristate-13-acetate (PMA), 1,2-dioctanoyl-sn-glycerol (DOG), and platelet-derived growth factor alpha are potent inducers of angiopoietin-like protein 4 (ANGPTL4) expression in several normal lung cell types and carcinoma cell lines. In human airway smooth muscle (HASM) cells induction of ANGPTL4 expression is observed as early as 2 h after the addition of PMA. PMA also increases the level of ANGPTL4 protein released in the medium. PKC inhibitors Ro31-8820 and Gö6983 greatly inhibit the induction of ANGPTL4 mRNA by PMA suggesting that this up-regulation involves activation of PKC. Knockdown of several PKCs by corresponding siRNAs suggest a role for PKCalpha. PMA does not activate MAPK p38 and p38 inhibitors have little effect on the induction of ANGPTL4 indicating that p38 is not involved in the regulation of ANGPTL4 by PMA. In contrast, treatment of HASM by PMA induces phosphorylation and activation of Ra, MEK1/2, ERK1/2, JNK, Elk-1, and c-Jun. The Ras inhibitor manumycin A, the MEK1/2 inhibitor U0126, and the JNK inhibitor SP600125, greatly reduce the increase in ANGPTL4 expression by PMA. Knockdown of MEK1/2 and JNK1/2 expression by corresponding siRNAs inhibits the induction of ANGPTL4. Our observations suggest that the induction of ANGPTL4 by PMA in HASM involves the activation of PKC, ERK, and JNK pathways. This induction may play a role in tissue remodeling during lung injury and be implicated in several lung pathologies.

U94 of human herpesvirus 6 inhibits in vitro angiogenesis and lymphangiogenesis

Human herpesvirus 6 (HHV-6) is a lymphotropic virus, but recent observations showed that also vascular endothelial cells (ECs) are susceptible to infection, both in vivo and in vitro. The observation that lymph nodes are a site of viral persistence suggests that lymphatic ECs (LECs) might be even more relevant for HHV-6 biology than vascular ECs. Here, we provide evidence that HHV-6 can infect LECs in vitro and establish a latent infection. Thus HHV-6 infection induces the loss of angiogenic properties both in LECs and in vascular ECs, as shown by the inability to form capillary-like structures and to seal wound scratches. The antiangiogenic effects observed in infected cells are associated to the expression of HHV-6 U94/rep, a latency-associated gene. In fact, transfection of U94/rep or addition of recombinant U94/REP protein to ECs inhibits the formation of in vitro capillary-like structures, reduces migration of ECs, and blocks angiogenesis, rendering rat aortic rings insensitive to VEGF-induced vasculogenetic activity. The ability of U94/rep to block different angiogenetic steps may lead to approaches in the potential control of the proliferation of blood and lymphatic vessels.

ADAMTS1, a putative anti-angiogenic factor, is decreased in human prostate cancer

OBJECTIVE

To investigate the expression of 'ADAM metallopeptidase with thrombospondin type I motif, 1' (ADAMTS1) in human prostate cancer, and to study its relationship to microvessel density (MVD) and metastasis. ADAMTS1 has been described as an anti-angiogenic and antitumour factor, but its function in prostate cancer is unknown.

PATIENTS AND METHODS

ADAMTS1 expression was evaluated by immunohistochemistry in specimens obtained by transurethral resection of the prostate from patients with hormone-naïve and hormone-refractory prostate tumours, including adjacent benign tissue. A semiquantitative scoring system was used for evaluating the staining. MVD was quantified by counting the number of CD34-positive blood vessels.

RESULTS

ADAMTS1 was strongly expressed in the luminal epithelial cells in benign prostate glands, whereas expression was significantly lower in prostate cancer cells. There was no obvious difference between hormone-naïve and hormone-refractory tumours, and ADAMTS1 expression did not correlate with Gleason score. However, in hormone-refractory tumours from patients with metastatic disease, the expression of ADAMTS1 was significantly lower than in tumours from patients without metastases. Furthermore, the MVD was higher in hormone-refractory than in hormone-naïve tumours and benign tissue, and MVD correlated with Gleason score. There was no association between ADAMTS1 and MVD in the hormone-naïve tumours, while hormone-refractory tumours with low ADAMTS1 expression had a higher MVD than those with moderate/high expression.

CONCLUSION

ADAMTS1 expression is decreased in prostate cancer, and might be involved in the early steps of prostate cancer development. Further, ADAMTS1 might have an anti-angiogenic and antimetastatic role in hormone-refractory prostate cancer, where low ADAMTS1 expression is associated with a high MVD and metastasis.

Role of peroxisome-proliferator-activated receptor beta/delta (PPARbeta/delta) in gastrointestinal tract function and disease

PPARbeta/delta (peroxisome-proliferator-activated receptor beta/delta) is one of three PPARs in the nuclear hormone receptor superfamily that are collectively involved in the control of lipid homoeostasis among other functions. PPARbeta/delta not only acts as a ligand-activated transcription factor, but also affects signal transduction by interacting with other transcription factors such as NF-kappaB (nuclear factor kappaB). Constitutive expression of PPARbeta/delta in the gastrointestinal tract is very high compared with other tissues and its potential physiological roles in this tissue include homoeostatic regulation of intestinal cell proliferation/differentiation and modulation of inflammation associated with inflammatory bowel disease and colon cancer. Analysis of mouse epithelial cells in the intestine and colon has clearly demonstrated that ligand activation of PPARbeta/delta induces terminal differentiation. The PPARbeta/delta target genes mediating this effect are currently unknown. Emerging evidence suggests that PPARbeta/delta can suppress inflammatory bowel disease through PPARbeta/delta-dependent and ligand-independent down-regulation of inflammatory signalling. However, the role of PPARbeta/delta in colon carcinogenesis remains controversial, as conflicting evidence suggests that ligand activation of PPARbeta/delta can either potentiate or attenuate this disease. In the present review, we summarize the role of PPARbeta/delta in gastrointestinal physiology and disease with an emphasis on findings in experimental models using both high-affinity ligands and null-mouse models.

Altered expression of genes regulating angiogenesis in experimental androgen-independent prostate cancer

BACKGROUND

The aim of this study was to investigate how the expression of genes regulating angiogenesis is altered when prostate cancer cells progress into androgen-independency.

METHODS

A gene array specific for angiogenesis was used to compare the human prostate cancer cell line LNCaP (androgen-dependent) with its more angiogenic and tumorigenic subline LNCaP-19 (androgen-independent). Results were verified with real-time RT-PCR, and further investigations were focused on the angiogenesis inhibitor a disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1). Expression of ADAMTS1 was investigated in vitro as well as in subcutaneous tumors with real-time RT-PCR and Western blotting. Microvessel density (MVD), versican proteolysis and protein levels of TIMP-2 and TIMP-3, known as ADAMTS1 inhibitors, were also analyzed in tumor xenografts.

RESULTS

The gene array revealed decreased expression of ADAMTS1, ephrin-A5, fibronectin 1, and neuropilin 1 in LNCaP-19 compared to LNCaP, while expression of midkine and VEGF were increased. Further studies showed that mRNA and protein levels of ADAMTS1 were significantly lower in LNCaP-19 compared to LNCaP, both in vitro and in subcutaneous tumors. The amount of ADAMTS1 correlated negatively with MVD, but no relation was found between ADAMTS1 and versican proteolysis.

CONCLUSIONS

Expression of several genes associated with angiogenesis was altered during transition into androgen-independency. Among these, a significant decrease was found for ADAMTS1, whose expression inversely correlated with MVD. Its role in progression of prostate cancer needs further investigation, but this inhibitor of angiogenesis could be an interesting candidate for future anti-angiogenic therapy.

Regulation of angiopoietin-like protein 4/fasting-induced adipose factor (Angptl4/FIAF) expression in mouse white adipose tissue and 3T3-L1 adipocytes

Angiopoietin-like protein 4 (Angptl4)/FIAF (fasting-induced adipose factor) was first identified as a target for PPAR and to be strongly induced in white adipose tissue (WAT) by fasting. Here we have examined the regulation of the expression and release of this adipokine in mouse WAT and in 3T3-L1 adipocytes. Angptl4/FIAF expression was measured by RT-PCR and real-time PCR; plasma Angptl4/FIAF and release of the protein in cell culture was determined by western blotting. The Angptl4/FIAF gene was expressed in each of the major WAT depots of mice, the mRNA level in WAT being similar to the liver and much higher (>50-fold) than skeletal muscle. Fasting mice (18 h) resulted in a substantial increase in Angptl4/FIAF mRNA in liver and muscle (9.5- and 21-fold, respectively); however, there was no effect of fasting on Angptl4/FIAF mRNA in WAT and the plasma level of Angptl4/FIAF was unchanged. The Angptl4/FIAF gene was expressed in 3T3-L1 adipocytes before and after differentiation, the level increasing post-differentiation; Angptl4/FIAF was released into the culture medium. Insulin, leptin, dexamethasone, noradrenaline, TNFalpha and several IL (IL-1beta, IL-6, IL-10, IL-18) had little effect on Angptl4/FIAF mRNA levels in 3T3-L1 adipocytes. However, a major stimulation of Angptl4/FIAF expression was observed with rosiglitazone and the inflammatory prostaglandins PGD2 and PGJ2. Angptl4/FIAF does not act as an adipose tissue signal of nutritional status, but is markedly induced by fasting in liver and skeletal muscle.

Meta-analysis of several gene lists for distinct types of cancer: a simple way to reveal common prognostic markers

Background

Although prognostic biomarkers specific for particular cancers have been discovered, microarray analysis of gene expression profiles, supported by integrative analysis algorithms, helps to identify common factors in molecular oncology. Similarities of Ordered Gene Lists (SOGL) is a recently proposed approach to meta-analysis suitable for identifying features shared by two data sets. Here we extend the idea of SOGL to the detection of significant prognostic marker genes from microarrays of multiple data sets. Three data sets for leukemia and the other six for different solid tumors are used to demonstrate our method, using established statistical techniques.

Results

We describe a set of significantly similar ordered gene lists, representing outcome comparisons for distinct types of cancer. This kind of similarity could improve the diagnostic accuracies of individual studies when SOGL is incorporated into the support vector machine algorithm. In particular, we investigate the similarities among three ordered gene lists pertaining to mesothelioma survival, prostate recurrence and glioma survival. The similarity-driving genes are related to the outcomes of patients with lung cancer with a hazard ratio of 4.47 (p = 0.035). Many of these genes are involved in breakdown of EMC proteins regulating angiogenesis, and may be used for further research on prognostic markers and molecular targets of gene therapy for cancers.

Conclusion

The proposed method and its application show the potential of such meta-analyses in clinical studies of gene expression profiles.

Secretory protein enrichment and analysis: an optimized approach applied on cancer cell lines using 2D LC-MS/MS

Reliable methods for profiling secretory proteins are highly desirable for the identification of biomarkers of disease progression. Secreted proteins are often masked by high amounts of protein supplements in the culture medium. We have developed an efficient method for the enrichment and analysis of the secretome of different cancer cell lines, free of essential contaminants. The method is based on the optimization of cell incubation conditions in protein-free medium. Secreted proteins are concentrated and fractionated using a reversed-phase tC2 Sorbent, followed by peptide mass fingerprinting for protein identification. An average of 88 proteins were identified in each cancer cell line, of which more than 76% are known to be secreted, possess a signal peptide or a transmembrane domain. Given the importance of secreted proteins as a source for early detection and diagnosis of disease, this approach may help to discover novel candidate biomarkers with potential clinical significance.