Doble synergetic anticancer activity through a combined chemo-photodynamic therapy and bioimaging of a novel Cas-ZnONPs all-in-one system.

A strategy for cancer treatment was implemented, based on chemo-photodynamic therapy, utilizing a novel formulation, low-cost system called Cas-ZnONPs. This system consisted of the incorporation of Casiopeina III-ia (CasIII-ia), a hydrophilic copper coordination compound with well-documented anti-neoplastic activity, on Zinc oxide nanoparticles (ZnONPs) with apoptotic activity and lipophilicity, allowing them to permeate biological barriers. Additionally, ZnONPs exhibited fluorescence, with emission at different wavelengths depending on their agglomeration and enabling real-time tracking biodistribution. Also, ZnONPs served as a sensitizer, generating reactive oxygen species (ROS) in situ. In in vitro studies on HeLa and MDA-MB-231 cell lines, a synergistic effect was observed with the impregnated CasIII-ia on ZnONPs. The anticancer activity had an increase in cellular inhibition, depending on the dose of exposure to UV-vis irradiation. In in vivo studies utilized zebrafish models for xenotransplanting stained MDA-MB-231 cells and testing the effectiveness of Cas-ZnONPs treatment. The treatment successfully eliminated cancer cells, both when combined with Photodynamic Therapy (PDT) and when used alone. However, a significantly higher concentration (50 times) of Cas-ZnONPs was required in the absence of PDT. This demonstrates the potential of Cas-ZnONPs in cancer treatment, especially when combined with PDT.

Betaglycan sustains HGF/Met signaling in lung cancer and endothelial cells promoting cell migration and tumor growth.

Persistent HGF/Met signaling drives tumor growth and dissemination. Proteoglycans within the tumor microenvironment might control HGF availability and signaling by affecting its accessibility to Met (HGF receptor), likely defining whether acute or sustained HGF/Met signaling cues take place. Given that betaglycan (BG, also known as type III TGFß receptor or TGFBR3), a multi-faceted proteoglycan TGFß co-receptor, can be found within the tumor microenvironment, we addressed its hypothetical role in oncogenic HGF signaling. We found that HGF/Met promotes lung cancer and endothelial cells migration via PI3K and mTOR. This effect was enhanced by recombinant soluble betaglycan (solBG) via a mechanism attributable to its glycosaminoglycan chains, as a mutant without them did not modulate HGF effects. Moreover, soluble betaglycan extended the effect of HGF-induced phosphorylation of Met, Akt, and Erk, and membrane recruitment of the RhoGEF P-Rex1. Data-mining analysis of lung cancer patient datasets revealed a significant correlation between high MET receptor, HGF, and PREX1 expression and reduced patient survival. Soluble betaglycan showed biochemical interaction with HGF and, together, they increased tumor growth in immunocompetent mice. In conclusion, the oncogenic properties of the HGF/Met pathway are enhanced and sustained by GAG-containing soluble betaglycan.

Adenoviral Vector Codifying for TNF as a Co-Adjuvant Therapy against Multi-Drug-Resistant Tuberculosis.

Mycobacterium tuberculosis is the main causal agent of pulmonary tuberculosis (TB); the treatment of this disease is long and involves a mix of at least four different antibiotics that frequently lead to abandonment, favoring the surge of drug-resistant mycobacteria (MDR-TB), whose treatment becomes more aggressive, being longer and more toxic. Thus, the search for novel strategies for treatment that improves time or efficiency is of relevance. In this work, we used a murine model of pulmonary TB produced by the MDR-TB strain to test the efficiency of gene therapy with adenoviral vectors codifying TNF (AdTNF), a pro-inflammatory cytokine that has protective functions in TB by inducing apoptosis, granuloma formation and expression of other Th1-like cytokines. When compared to the control group that received an adenoviral vector that codifies for the green fluorescent protein (AdGFP), a single dose of AdTNF at the chronic active stage of the disease produced total survival, decreasing bacterial load and tissue damage (pneumonia), which correlated with an increase in cells expressing IFN-γ, iNOS and TNF in pneumonic areas and larger granulomas that efficiently contain and eliminate mycobacteria. Second-line antibiotic treatment against MDR-TB plus AdTNF gene therapy reduced bacterial load faster within a week of treatment compared to empty vector plus antibiotics or antibiotics alone, suggesting that AdTNF is a new potential type of treatment against MDR-TB that can shorten second-line chemotherapy but which requires further experimentation in other animal models (non-human primates) that develop a more similar disease to human pulmonary TB.

Genistein-mediated thermogenesis and white-to-beige adipocyte differentiation involve transcriptional activation of cAMP response elements in the Ucp1 promoter.

Genistein is an isoflavone present in soybeans and is considered a bioactive compound due to its widely reported biological activity. We have previously shown that intraperitoneal genistein administration and diet supplementation activates the thermogenic program in rats and mice subcutaneous white adipose tissue (scWAT) under multiple environmental cues, including cold exposure and high-fat diet feeding. However, the mechanistic insights of this process were not previously unveiled. Uncoupling protein 1 (UCP1), a mitochondrial membrane polypeptide responsible for dissipating energy into heat, is considered the most relevant thermogenic marker; thus, we aimed to evaluate whether genistein regulates UCP1 transcription. Here we show that genistein administration to thermoneutral-housed mice leads to the appearance of beige adipocyte markers, including a sharp upregulation of UCP1 expression and protein abundance in scWAT. Reporter assays showed an increase in UCP1 promoter activity after genistein stimulation, and in silico analysis revealed the presence of estrogen (ERE) and cAMP (CRE) response elements as putative candidates of genistein activation. Mutation of the CRE but not the ERE reduced genistein-induced promoter activity by 51%. Additionally, in vitro and in vivo ChIP assays demonstrated the binding of CREB to the UCP1 promoter after acute genistein administration. Taken together, these data elucidate the mechanism of genistein-mediated UCP1 induction and confirm its potential applications in managing metabolic disorders.

Fluorescent Probe for in Vivo Partitioning into Dynamic Lipid Droplets Enables Monitoring of Water Permeability-Induced Edema.

Lipid droplets (LDs) are intracellular organelles found in most cell types from adipocytes to cancer cells. Although recent investigations have implicated LDs in numerous diseases, the current available methods to monitor them in vertebrate models rely on static imaging using fluorescent dyes, limiting the investigation of their rapid in vivo dynamics. Here, we report a fluorophore chemistry approach to enable in vivo LD dynamic monitoring using a Nernstian partitioning mechanism. Interestingly, the effect of atorvastatin and osmotic treatments toward LDs revealed an unprecedented dynamic enhancement. Then, using a designed molecular probe with an optimized response to hydration and LD dynamics applied to Zebrafish developing pericardial and yolk-sac edema, which represents a tractable model of a human cardiovascular disease, we also provide a unique dual method to detect disease evolution and recovery.

CD24+CD44+CD54+EpCAM+ gastric cancer stem cells predict tumor progression and metastasis: clinical and experimental evidence.

BACKGROUND: Gastric cancer (GC) is a leading cause of cancer-related deaths worldwide. Specific and thorough identification of cancer cell subsets with higher tumorigenicity and chemoresistance, such as cancer stem cells (CSCs), could lead to the development of new and promising therapeutic targets. For better CSC identification, a complete or extended surface marker phenotype is needed to provide increased specificity for new cell targeting approaches. Our goal is to identify and characterize a putative extended phenotype for CSCs derived from patients with GC before treatment, as well as to evaluate its clinical value. In addition, we aim to ensure that cells with this phenotype have stemness and self-renewal capabilities. METHODS: This is a cohort study including 127 treatment-naïve patients with GC who attended the Instituto Nacional de Cancerología. Multiparametric flow cytometry analysis was performed to determine the extended phenotype of cells derived from gastric biopsies. The tumorigenic capability of cells identified in patients was assessed in a zebrafish model. RESULTS: CD24+CD44+CD54+EpCAM+ cells were present in all treatment-naïve patients included, with a median abundance of 1.16% (0.57-1.89%). The percentage of CD24+CD44+CD54+EpCAM+ cells was categorized as high or low using 1.19% as the cutoff for the CD24+CD44+CD54+EpCAM+ cell subset. Additionally, a higher TNM stage correlated with a higher percentage of CD24+CD44+CD54+EpCAM+ cells (Rho coefficient 0.369; p < 0.0001). We also demonstrated that a higher percentage of CD24+CD44+CD54+EpCAM+ cells was positively associated with metastasis. The metastatic potential of these cells was confirmed in a zebrafish model. Ultimately, under our conditions, we conclude that CD24+CD44+CD54+EpCAM+ cells are true gastric cancer stem cells (GCSCs). CONCLUSION: The CD24+CD44+CD54+EpCAM+ cells present in tissue samples from patients are true GCSCs. This extended phenotype results in better and more specific characterization of these highly tumorigenic cells. The relative quantification of CD24+CD44+CD54+EpCAM+ cells has potential clinical value, as these cells are associated with metastatic disease, making their presence an additional prognostic marker and possibly a target for the design of new antineoplastic treatments in the era of precision oncology. Overall, the extended CD24+CD44+CD54+EpCAM+ phenotype of GCSCs could support their isolation for the study of their stemness mechanisms, leading to the identification of better molecular targets for the development of both new therapeutic approaches such as oncoimmunotherapy and new diagnostic and clinical prognostic strategies for GC.

Immune Regulatory Effect of Osteopontin Gene Therapy in a Murine Model of Multidrug Resistant Pulmonary Tuberculosis.

Tuberculosis (TB) has been for many years a major public health problem since treatment is long and sometimes ineffective favoring the increase of multidrug-resistant mycobacteria (MDR-TB). Gene therapy is a novel and effective tool to regulate immune responses. In this study we evaluated the therapeutic effect of an adenoviral vector codifying osteopontin (AdOPN), a molecule known for their roles to favor Th1 and Th17 type-cytokine expression which are crucial in TB containment. A single dose of AdOPN administration in BALB/c mice suffering late progressive pulmonary MDR-TB produced significant lower bacterial load and pneumonia, due to higher expression of IFN-γ, IL-12, and IL-17 in coexistence with increase of granulomas in number and size, resulting in higher survival, in contrast with mice treated with the control adenovirus that codify the green fluorescent protein (AdGFP). Combined therapy of AdOPN with a regimen of second line antibiotics produced a better control of bacterial load in lung during the first days of treatment, suggesting that AdOPN can shorten chemotherapy. Taken together, gene therapy with AdOPN leads to higher immune responses against TB infection, resulting in a new potential treatment against pulmonary TB that can co-adjuvant chemotherapy.

The HGR motif is the antiangiogenic determinant of vasoinhibin: implications for a therapeutic orally active oligopeptide.

The hormone prolactin acquires antiangiogenic and antivasopermeability properties after undergoing proteolytic cleavage to vasoinhibin, an endogenous prolactin fragment of 123 or more amino acids that inhibits the action of multiple proangiogenic factors. Preclinical and clinical evidence supports the therapeutic potential of vasoinhibin against angiogenesis-related diseases including diabetic retinopathy, peripartum cardiomyopathy, rheumatoid arthritis, and cancer. However, the use of vasoinhibin in the clinic has been limited by difficulties in its production. Here, we removed this barrier to using vasoinhibin as a therapeutic agent by showing that a short linear motif of just three residues (His46-Gly47-Arg48) (HGR) is the functional determinant of vasoinhibin. The HGR motif is conserved throughout evolution, its mutation led to vasoinhibin loss of function, and oligopeptides containing this sequence inhibited angiogenesis and vasopermeability with the same potency as whole vasoinhibin. Furthermore, the oral administration of an optimized cyclic retro-inverse vasoinhibin heptapeptide containing HGR inhibited melanoma tumor growth and vascularization in mice and exhibited equal or higher antiangiogenic potency than other antiangiogenic molecules currently used as anti-cancer drugs in the clinic. Finally, by unveiling the mechanism that obscures the HGR motif in prolactin, we anticipate the development of vasoinhibin-specific antibodies to solve the on-going challenge of measuring endogenous vasoinhibin levels for diagnostic and interventional purposes, the design of vasoinhibin antagonists for managing insufficient angiogenesis, and the identification of putative therapeutic proteins containing HGR.

Chordacentrum mineralization is delayed in zebrafish betaglycan-null mutants.

BACKGROUND: The Transforming Growth Factor ß (TGFß) family is a group of related proteins that signal through a type I and type II receptors. Betaglycan, also known as the type III receptor (Tgfbr3), is a coreceptor for various ligands of the TGFß family that participates in heart, liver and kidney development as revealed by the tgfbr3-null mouse, as well as in angiogenesis as revealed by Tgfbr3 downregulation in morphant zebrafish. RESULTS: Here, we present CRISPR/Cas9-derived zebrafish Tgfbr3-null mutants, which exhibited unaltered embryonic angiogenesis and developed into fertile adults. One reproducible phenotype displayed by these Tgfbr3-null mutants is delayed chordacentra mineralization, which nonetheless does not result in vertebral abnormalities in the adult fishes. We also report that the canonical TGFß signaling pathway is needed for proper chordacentra mineralization and that Tgfbr3 absence decreases this signal in the notochordal cells responsible for this process. CONCLUSION: Betaglycan's "ligand presentation" function contributes to the optimal TGFß signaling required for zebrafish chordacentra mineralization.

Vasoinhibin Suppresses Nerve Growth Factor-Induced Differentiation and Survival of PC12 Pheochromocytoma Cells.

BACKGROUND: Vasoinhibin, a protein derived from prolactin, regulates various vascular functions including endothelial cell survival. Of note, vasoinhibin is present in the central nervous system, where it triggers neuroendocrine and behavioral responses to stress. Moreover, vasoinhibin compromises nerve growth factor (NGF)-induced neurite outgrowth in primary sensory neurons of the peripheral nervous system. Nonetheless, information on the functions of vasoinhibin in developing neurons remains limited. The present study explored whether vasoinhibin affects the neurotrophic actions of NGF by measuring the cell differentiation and survival of PC12 pheochromocytoma cells. METHODS: The effects of recombinant or lentiviral vector-transduced human vasoinhibin were tested on differentiating PC12 cells. Neurite outgrowth was quantified by measuring their length and density. The MTT assay was employed to assess cell viability, and ELISA was used to quantify DNA fragmentation as an index of apoptosis. Phosphorylated Akt and ERK1/2 were analyzed by Western blotting. RESULTS: The addition of a human recombinant vasoinhibin, and the transduction of a lentiviral vector carrying a human vasoinhibin sequence, significantly reduced NGF-induced neurite outgrowth, cell survival, and phosphorylation of Akt and ERK1/2, and increased DNA fragmentation and caspase 3 activation in PC12 cells. CONCLUSIONS: Vasoinhibin downregulates NGF-induced differentiation and survival of PC12 cells, blocking tropomyosin receptor kinase A-triggered signaling pathways and increasing apoptosis. These results establish that vasoinhibin interaction with NGF and other neurotrophins may be critical in mediating pathways involved in neuronal survival and differentiation.

Gene therapy based in antimicrobial peptides and proinflammatory cytokine prevents reactivation of experimental latent tuberculosis.

Mycobacterium tuberculosis (Mtb) latent infection can lead to reactivation. The design of new strategies to prevent it is an important subject. B6D2F1 mice were infected intratracheally with a low dose of Mtb H37Rv to induce chronic infection. After 7 months, mice were treated with one dose of recombinant adenoviruses encoding TNFα, ß defensin-3 and LL37. Immunosupression was induced 1 month later with corticosterone. In comparison with the control group, mice treated with adenoviruses showed significantly less bacterial load and pneumonia, the adenoviruses encoding TNFα and LL37 being the most efficient. Gene therapy based in a proinflammatory cytokine or antimicrobial peptides is a potentially useful system to prevent reactivation of latent tuberculosis.

Proteolytic control of TGF-ß co-receptor activity by BMP-1/tolloid-like proteases revealed by quantitative iTRAQ proteomics.

The metalloproteinase BMP-1 (bone morphogenetic protein-1) plays a major role in the control of extracellular matrix (ECM) assembly and growth factor activation. Most of the growth factors activated by BMP-1 are members of the TGF-ß superfamily known to regulate multiple biological processes including embryonic development, wound healing, inflammation and tumor progression. In this study, we used an iTRAQ (isobaric tags for relative and absolute quantification)-based quantitative proteomic approach to reveal the release of proteolytic fragments from the cell surface or the ECM by BMP-1. Thirty-eight extracellular proteins were found in significantly higher or lower amounts in the conditioned medium of HT1080 cells overexpressing BMP-1 and thus, could be considered as candidate substrates. Strikingly, three of these new candidates (betaglycan, CD109 and neuropilin-1) were TGF-ß co-receptors, also acting as antagonists when released from the cell surface, and were chosen for further substrate validation. Betaglycan and CD109 proved to be directly cleaved by BMP-1 and the corresponding cleavage sites were extensively characterized using a new mass spectrometry approach. Furthermore, we could show that the ability of betaglycan and CD109 to interact with TGF-ß was altered after cleavage by BMP-1, leading to increased and prolonged SMAD2 phosphorylation in BMP-1-overexpressing cells. Betaglycan processing was also observed in primary corneal keratocytes, indicating a general and novel mechanism by which BMP-1 directly affects signaling by controlling TGF-ß co-receptor activity. The proteomic data have been submitted to ProteomeXchange with the identifier PXD000786 and doi: 10.6019/PXD000786 .

Betaglycan (TßRIII) is expressed in the thymus and regulates T cell development by protecting thymocytes from apoptosis.

TGF-ß type III receptor (TßRIII) is a coreceptor for TGFß family members required for high-affinity binding of these ligands to their receptors, potentiating their cellular functions. TGF-ß [1]-[3], bone morphogenetic proteins (BMP2/4) and inhibins regulate different checkpoints during T cell differentiation. Although TßRIII is expressed on hematopoietic cells, the role of this receptor in the immune system remains elusive. Here, we provide the first evidence that TßRIII is developmentally expressed during T cell ontogeny, and plays a crucial role in thymocyte differentiation. Blocking of endogenous TßRIII in fetal thymic organ cultures led to a delay in DN-DP transition. In addition, in vitro development of TßRIII(-/-) thymic lobes also showed a significant reduction in absolute thymocyte numbers, which correlated with increased thymocyte apoptosis, resembling the phenotype reported in Inhibin α (-/-) thymic lobes. These data suggest that Inhibins and TßRIII may function as a molecular pair regulating T cell development.

TGF-ß signalling is mediated by two autonomously functioning TßRI:TßRII pairs.

Transforming growth factor (TGF)-ßs are dimeric polypeptides that have vital roles in regulating cell growth and differentiation. They signal by assembling a receptor heterotetramer composed of two TßRI:TßRII heterodimers. To investigate whether the two heterodimers bind and signal autonomously, one of the TGF-ß protomers was substituted to block receptor binding. The substituted dimer, TGF-ß3 WD, bound the TßRII extracellular domain and recruited the TßRI with affinities indistinguishable from TGF-ß3, but with one-half the stoichiometry. TGF-ß3 WD was further shown to retain one-quarter to one-half the signalling activity of TGF-ß3 in three established assays for TGF-ß function. Single-molecule fluorescence imaging with GFP-tagged receptors demonstrated a measurable increase in the proportion of TßRI and TßRII dimers upon treatment with TGF-ß3, but not with TGF-ß3 WD. These results provide evidence that the two TßRI:TßRII heterodimers bind and signal in an autonomous manner. They further underscore how the TGF-ßs diverged from the bone morphogenetic proteins, the ancestral ligands of the TGF-ß superfamily that signal through a RI:RII:RII heterotrimer.

Therapeutic effect of recombinant adenovirus encoding interferon-gamma in a murine model of progressive pulmonary tuberculosis.

We constructed recombinant adenoviruses encoding murine interferon-gamma (AdIFNgamma) and tested its therapeutic efficiency in a well characterized model of progressive pulmonary tuberculosis (TB) in Balb/c mice, infected through the trachea with the laboratory drug-susceptible H37Rv strain or multidrug-resistant (MDR) clinical isolate. When the disease was in a late phase, 2 months after infection, we administered by intratracheal cannulation a single dose [1.7 x 10(9) plaque forming units (pfu)] of AdIFNgamma or the control adenovirus. Groups of mice were killed at different time-points and the lungs were examined to determine bacilli colony forming units (CFU), cytokine/chemokine gene expression, and CD4/CD8 subpopulations, and also subjected to automated histomorphometry. In comparison with the control group, after 2 weeks of treatment and during the next 6 months, AdIFNgamma-treated animals infected with either the H37Rv strain or the MDR strain showed significantly lower bacilli loads and tissue damage (pneumonia), higher expressions of IFN-gamma, tumor necrosis factor (TNF), and inducible nitric oxide synthase (iNOS), and bigger granulomas. When compared with the results from conventional chemotherapy or AdIFNgamma treatment alone, the combined treatment with AdIFNgamma plus conventional chemotherapy shortened the time taken for reduction of bacillary load. This shows that gene therapy with AdIFNgamma efficiently reconstituted the protective immune response and controlled the progress of pulmonary TB produced by MDR or non-MDR strains.

Therapeutic Effect of Recombinant Adenovirus Encoding Interferon-γ in a Murine Model of Progressive Pulmonary Tuberculosis.

We constructed recombinant adenoviruses encoding murine interferon-γ (AdIFNγ) and tested its therapeutic efficiency in a well characterized model of progressive pulmonary tuberculosis (TB) in Balb/c mice, infected through the trachea with the laboratory drug-susceptible H37Rv strain or multidrug-resistant (MDR) clinical isolate. When the disease was in a late phase, 2 months after infection, we administered by intratracheal cannulation a single dose [1.7 × 109 plaque forming units (pfu)] of AdIFNγ or the control adenovirus. Groups of mice were killed at different time-points and the lungs were examined to determine bacilli colony forming units (CFU), cytokine/chemokine gene expression, and CD4/CD8 subpopulations, and also subjected to automated histomorphometry. In comparison with the control group, after 2 weeks of treatment and during the next 6 months, AdIFNγ-treated animals infected with either the H37Rv strain or the MDR strain showed significantly lower bacilli loads and tissue damage (pneumonia), higher expressions of IFN-γ, tumor necrosis factor (TNF), and inducible nitric oxide synthase (iNOS), and bigger granulomas. When compared with the results from conventional chemotherapy or AdIFNγ treatment alone, the combined treatment with AdIFNγ plus conventional chemotherapy shortened the time taken for reduction of bacillary load. This shows that gene therapy with AdIFNγ efficiently reconstituted the protective immune response and controlled the progress of pulmonary TB produced by MDR or non-MDR strains.

A new highly effective anticysticercosis vaccine expressed in transgenic papaya.

The use of transgenic plants as new antigen-delivery systems for subunit vaccines has been increasingly explored. We herein report progress toward a papaya-based vaccine against cysticercosis. Synthetic peptides (KETc1, KETc12, KETc7) were successfully expressed in 19 different transgenic papaya clones and found to be immunogenic. Complete protection against cysticercosis was induced with the soluble extract of the clones that expressed the higher levels of transcripts in up to 90% of the immunized mice. This study represents a key step towards the development of a more effective, sustainable and affordable oral subunit vaccine against human and pig cysticercosis.

Three key residues underlie the differential affinity of the TGFbeta isoforms for the TGFbeta type II receptor.

TGFbeta1, beta2, and beta3 are 25kDa homodimeric polypeptides that play crucial non-overlapping roles in development, tumor suppression, and wound healing. They exhibit 70-82% sequence identity and transduce their signals by binding and bringing together the TGFbeta type I and type II receptors, TbetaRI and TbetaRII. TGFbeta2 differs from the other isoforms in that it binds TbetaRII weakly and is dependent upon the co-receptor betaglycan for function. To explore the physicochemical basis underlying these differences, we generated a series of single amino acid TbetaRII variants based on the crystal structure of the TbetaRII:TGFbeta3 complex and examined these in terms of their TGFbeta isoform binding affinity and their equilibrium stability. The results showed that TbetaRII Ile53 and Glu119, which contact TGFbeta3 Val92 and Arg25, respectively, together with TbetaRII Asp32, Glu55, and Glu75, which contact TGFbeta3 Arg94, each contribute significantly, between 1 kcal mol(-1) to 1.5 kcal mol(-1), to ligand binding affinities. These contacts likely underlie the estimated 4.1 kcal mol(-1) lower affinity with which TbetaRII binds TGFbeta2 as these three ligand residues are unchanged in TGFbeta1 but are conservatively substituted in TGFbeta2 (Lys25, Ile92, and Lys94). To test this hypothesis, a TGFbeta2 variant was generated in which these three residues were changed to those in TGFbetas 1 and 3. This variant exhibited receptor binding affinities comparable to those of TGFbetas 1 and 3. Together, these results show that these three residues underlie the lowered affinity of TGFbeta2 for TbetaRII and that all isoforms likely induce assembly of the TGFbeta signaling receptors in the same overall manner.

Systemic administration of a soluble betaglycan suppresses tumor growth, angiogenesis, and matrix metalloproteinase-9 expression in a human xenograft model of prostate cancer.

BACKGROUND: Transforming growth factor beta (TGFbeta) over-expression in prostate cancer has been shown to promote tumor progression and neo-vascularization. In this study, we have investigated the efficacy and the potential mechanism of a TGFbeta antagonist, a recombinant soluble betaglycan (sBG), as a prostate cancer therapeutic agent after systemic administration in a xenograft model. METHODS: Recombinant sBG was delivered continuously via ALZET osmotic pumps or by daily bolus i.p. injection at 4.2 mg/kg/day for 14 days in human prostate cancer DU145 xenograft bearing nude mice. Tumors were analyzed for their size, blood volume by hemoglobin assay, microvessel density (MVD) by CD-31 immunostaining, and apoptosis by TUNEL assay. Matrix metalloproteinase-9 (MMP-9) activity and expression in the DU145 conditioned media were determined by gelatin zymography and Western blotting, respectively. Tissue sections were stained with a polyclonal antibody to MMP-9 using an immuno-fluorescence method. RESULTS: Continuous or bolus administration of sBG showed a similar significant inhibition of DU145 xenograft growth associated with a reduced tumor blood volume and MVD, and an enhanced intra-tumoral apoptosis. Treatment with sBG inhibited both endogenous and TGFbeta-induced MMP-9 activity and expression in a dose-dependent manner in vitro and reduced in vivo MMP-9 expression in DU145 xenografts. CONCLUSIONS: Our results for the first time indicate that TGFbeta blockade by systemic sBG administration can inhibit DU145 prostate xenograft growth and angiogenesis. The inhibition is likely in part mediated by the attenuation of TGFbeta-induced MMP-9 expression.