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At least 253 records · Page 14

Transforming growth factor-β synthesized by stromal cells and cancer cells participates in bone resorption induced by oral squamous cell carcinoma

Transforming growth factor beta (TGF-β) plays a significant role in the regulation of the tumor microenvironment. To explore the role of TGF-β in oral cancer-induced bone destruction, we investigated the immunohistochemical localization of TGF-β and phosphorylated Smad2 (p-Smad2) in 12 surgical specimens of oral squamous cell carcinoma (OSCC). These studies revealed TGF-β and p-Smad2 expression in cancer cells in all tested cases. Several fibroblasts located between cancer nests and resorbing bone expressed TGF-β in 10 out of 12 cases and p-Smad2 in 11 out of 12 cases. Some osteoclasts also exhibited p ∼ Smad2 expression. The OSCC cell line, HSC3, and the bone marrow-derived fibroblastic cell line, ST2, synthesized substantial levels of TGF-β. Culture media derived from HSC3 cells could stimulate Tgf-β1 mRNA expression in ST2 cells. Recombinant TGF-β1 could stimulate osteoclast formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264 cells. TGF-β1 could upregulate the expression of p-Smad2 in RAW264 cells, and this action was suppressed by the addition of a neutralizing antibody against TGF-β or by SB431542. Transplantation of HSC3 cells onto the calvarial region of athymic mice caused bone destruction, associated with the expression of TGF-β and p-Smad2 in both cancer cells and stromal cells. The bone destruction was substantially inhibited by the administration of SB431542. The present study demonstrated that TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction. - Highlights: • Cancer cell, fibroblastic cells, and osteoclasts at bone resorbing area by oral cancer exhibited TGF-β and p-Smad2. • TGF-β1 stimulated osteoclastogenesis induced by RAKL in RAW264 cell. • Xenograft model of oral cancer-induced bone resorption was substantially inhibited by SB431542. • TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction.

60 APPLIED LIFE SCIENCES↗

Autoantibodies in dilated cardiomyopathy induce vascular endothelial growth factor expression in cardiomyocytes

Background: Autoantibodies have been identified as major predisposing factors for dilated cardiomyopathy (DCM). Patients with DCM show elevated serum levels of vascular endothelial growth factor (VEGF) whose source is unknown. Besides its well-investigated effects on angiogenesis, evidence is present that VEGF signaling is additionally involved in fibroblast proliferation and cardiomyocyte hypertrophy, hence in cardiac remodeling. Whether autoimmune effects in DCM impact cardiac VEGF signaling needs to be elucidated. Methods: Five DCM patients were treated by the immunoadsorption (IA) therapy on five consecutive days. The eluents from the IA columns were collected and prepared for cell culture. Cardiomyocytes from neonatal rats (NRCM) were incubated with increasing DCM-immunoglobulin-G (IgG) concentrations for 48 h. Polyclonal IgG (Venimmun N), which was used to restore IgG plasma levels in DCM patients after the IA therapy was additionally used for control cell culture purposes. Results: Elevated serum levels of VEGF decreased significantly after IA (Serum VEGF (ng/ml); DCM pre-IA: 45 ± 9.1 vs. DCM post–IA: 29 ± 6.7; P < 0.05). In cell culture, pretreatment of NRCM by DCM-IgG induced VEGF expression in a time and dose dependent manner. Biologically active VEGF that was secreted by NRCM significantly increased BNP mRNA levels in control cardiomyocytes and induced cell-proliferation of cultured cardiac fibroblast (Fibroblast proliferation; NRCM medium/HC-IgG: 1 ± 0.0 vs. NRCM medium/DCM-IgG 100 ng/ml: 5.6 ± 0.9; P < 0.05). Conclusion: The present study extends the knowledge about the possible link between autoimmune signaling in DCM and VEGF induction. Whether this observation plays a considerable role in cardiac remodeling during DCM development needs to be further elucidated. - Highlights: • Mechanisms of remodeling in dilated cardiomyopathy (DCM) are not fully understood. • Autoantibodies have been identified as major predisposing factors for DCM. • DCM patients show high serum levels of VEGF. • Recent data indicate that VEGF is involved in cardiac remodeling processes. • Whether autoimmune processes in DCM are involved in VEGF signaling are unclear.

60 APPLIED LIFE SCIENCES↗

Wound healing potential of adipose tissue stem cell extract

Adipose tissue stem cells (ATSCs) are considered as a promising source in the field of cell therapy and regenerative medicine. In addition to direct cell replacement using stem cells, intercellular molecule exchange by stem cell secretory factors showed beneficial effects by reducing tissue damage and augmentation of endogenous repair. Delayed cutaneous wound healing is implicated in many conditions such as diabetes, aging, stress and alcohol consumption. However, the effects of cell-free extract of ATSCs (ATSC-Ex) containing secretome on wound healing process have not been investigated. In this study, ATSC-Ex was topically applied on the cutaneous wound and healing speed was examined. As a result, wound closure was much faster in the cell-free extract treated wound than control wound at 4, 6, 8 days after application of ATSC-Ex. Dermal fibroblast proliferation, migration and extracellular matrix (ECM) production are critical aspects of wound healing, and the effects of ATSC-Ex on human dermal fibroblast (HDF) was examined. ATSC-Ex augmented HDF proliferation in a dose-dependent manner and migration ability was enhanced by extract treatment. Representative ECM proteins, collagen type I and matrix metalloproteinase-1, are significantly up-regulated by treatment of ATSC-Ex. Our results suggest that the ATSC-Ex have improving effect of wound healing and can be the potential therapeutic candidate for cutaneous wound healing. - Highlights: • Topical application of ATSC-Ex results in faster wound closure than normal wound in vivo. • ATSC-Ex enhances dermal fibroblast proliferation, migration and extracellular matrix production. • This study suggests that ATSC-Ex is an effective source to augment wound healing.

60 APPLIED LIFE SCIENCES↗

MiR-628-5p decreases the tumorigenicity of epithelial ovarian cancer cells by targeting at FGFR2

Highlights: • miR-628-5p decreases the stem like cell percentage of epithelial ovarian cancer cells by inducing their apoptosis. • miR-628-5p decreases the tumourigenecity of epithelial ovarian cancer cells. • miR-628-5p targets at and down regulates the expression of fibroblast growth factor receptor 2. • Fibroblast growth factor receptor 2 expresses higher in ovarian cancer tissues and is correlated with worse prognosis. Micro RNAs (miRNAs) are small non-coding RNAs which are 19–24 nucleotides in length. MiRNAs play a vital role in the whole process of tumour development, but how they influence the tumourigenecity of epithelial ovarian cancer (EOC)cells is rarely researched. In our study, it was verified that miR-628-5p decreased the stem like cell percentage of EOC cells by inducing their apoptosis. The animal experiments showed that miR-628-5p decreased the tumourigenecity of EOC cells. Besides, we found miR-628-5p targeted at and down-regulated the expression of fibroblast growth factor receptor 2 (FGFR2). FGFR2 expressed higher in ovarian cancer tissues and was correlated with worse prognosis. Our findings indicated that miR-628-5pplays an important role in ovarian cancer stem cell driven tumorigenesis.

60 APPLIED LIFE SCIENCES↗

Apixaban attenuates ischemia-induced myocardial fibrosis by inhibition of Gq/PKC signaling

Highlights: • Apixaban attenuates ischemia-induced myocardial fibrosis. • Ischemia-induced myocardial fibrosis shows higher thrombin level. • Thrombin induced collagen deposition in cardiac fibroblasts. • Thrombin induced collagen deposition by activation of Gq/PKC signaling. • Inhibition of Gq/PKC blunts ischemia-induced myocardial fibrosis. It was previously found that patients with symptom of myocardial dysfunction had increased levels of thrombin. Apixaban is one of the novel oral anticoagulant drugs widely used in clinic. As the inhibitor of FXa (prothrombin), it inhibits prothrombin conversion into thrombin leading to thrombin deficiency in vivo. However, the effects of apixaban on myocardial fibrosis were still unclear, and the concomitant molecular mechanisms remain to be investigated. Here, we showed that myocardial fibrosis-bearing mice induced by continuous myocardial ischemia (MI) had higher levels of thrombin. Orally administration of apixaban significantly abrogated fibrosis condition and thrombin levels. In vitro, thrombin induced collagen deposition in primary cardiac fibroblasts in a dose-dependent manner. Mechanistic experiments showed that thrombin induced collagen deposition by activation of the Par-1-coupled Gq/PKC signaling. Genetic ablation of Gq or pharmacological inhibition of PKC effectively blunted thrombin-induced collagen deposition in cardiac fibroblasts. Moreover, administration of PKC inhibitor or Gq antagonist obviously blocked MI-induced myocardial fibrosis in mice. To conclude, apixaban attenuates MI-induced myocardial fibrosis by inhibition of thrombin-dependent Par-1/Gq/PKC signaling axis.

60 APPLIED LIFE SCIENCES↗

A dioxin-like compound induces hyperplasia and branching morphogenesis in mouse mammary gland, through alterations in TGF-β1 and aryl hydrocarbon receptor signaling

Hexachlorobenzene (HCB) is a widespread environmental pollutant and a dioxin-like compound that binds weakly to the aryl hydrocarbon receptor (AhR). Because AhR and transforming growth factor β1 (TGF-β1) converge to regulate common signaling pathways, alterations in this crosstalk might contribute to developing preneoplastic lesions. The aim of this study was to evaluate HCB action on TGF-β1 and AhR signaling in mouse mammary gland, through AhR +/+ and AhR −/− models. Results showed a differential effect in mouse mammary epithelial cells (NMuMG), depending on the dose: 0.05 μM HCB induced cell migration and TGF-β1 signaling, whereas 5 μM HCB reduced cell migration, promoted cell cycle arrest and stimulated the dioxin response element (DRE) -dependent pathway. HCB (5 μM) enhanced α-smooth muscle actin expression and decreased TGF-β receptor II mRNA levels in immortalized mouse mammary fibroblasts AhR +/+, resembling the phenotype of transformed cells. Accordingly, their conditioned medium was able to enhance NMuMG cell migration. Assays in C57/Bl6 mice showed HCB (3 mg/kg body weight) to enhance ductal hyperplasia, cell proliferation, estrogen receptor α nuclear localization, branch density, and the number of terminal end buds in mammary gland from AhR +/+ mice. Primary culture of mammary epithelial cells from AhR +/+ mice showed reduced AhR mRNA levels after HCB exposure (0.05 and 5 μM). Interestingly, AhR −/− mice exhibited an increase in ductal hyperplasia and mammary growth in the absence of HCB treatment, thus revealing the importance of AhR in mammary development. Our findings show that environmental HCB concentrations modulate AhR and TGF-β1 signaling, which could contribute to altered mammary branching morphogenesis, likely leading to preneoplastic lesions and retaining terminal end buds. - Highlights: • 0.05 μM HCB induces migration and TGF-β1 signaling in mammary epithelial cells NMuMG. • 5 μM HCB reduces migration, and promotes cell cycle arrest and AhR nuclear pathway in NMuMG. • HCB enhances α-SMA and decreases TGF-β receptor II expression in fibroblasts AhR +/+. • Conditioned medium from fibroblasts AhR +/+ exposed to HCB enhances NMuMG migration. • HCB increases hyperplasia and branching morphogenesis in AhR +/+ mice mammary gland.

60 APPLIED LIFE SCIENCES↗

Defining the role of mesenchymal stromal cells on the regulation of matrix metalloproteinases in skeletal muscle cells

Recent studies indicate that mesenchymal stromal cell (MSC) transplantation improves healing of injured and diseased skeletal muscle, although the mechanisms of benefit are poorly understood. In the present study, we investigated whether MSCs and/or their trophic factors were able to regulate matrix metalloproteinase (MMP) expression and activity in different cells of the muscle tissue. MSCs in co-culture with C2C12 cells or their conditioned medium (MSC-CM) up-regulated MMP-2 and MMP-9 expression and function in the myoblastic cells; these effects were concomitant with the down-regulation of the tissue inhibitor of metalloproteinases (TIMP)-1 and -2 and with increased cell motility. In the single muscle fiber experiments, MSC-CM administration increased MMP-2/9 expression in Pax-7{sup +} satellite cells and stimulated their mobilization, differentiation and fusion. The anti-fibrotic properties of MSC-CM involved also the regulation of MMPs by skeletal fibroblasts and the inhibition of their differentiation into myofibroblasts. The treatment with SB-3CT, a potent MMP inhibitor, prevented in these cells, the decrease of α-smooth actin and type-I collagen expression induced by MSC-CM, suggesting that MSC-CM could attenuate the fibrogenic response through mechanisms mediated by MMPs. Our results indicate that growth factors and cytokines released by these cells may modulate the fibrotic response and improve the endogenous mechanisms of muscle repair/regeneration. - Highlights: • MSC-CM contains paracrine factors that up-regulate MMP expression and function in different skeletal muscle cells. • MSC-CM promotes myoblast and satellite cell migration, proliferation and differentiation. • MSC-CM negatively interferes with fibroblast-myoblast transition in primary skeletal fibroblasts. • Paracrine factors from MSCs modulate the fibrotic response and improve the endogenous mechanisms of muscle regeneration.

60 APPLIED LIFE SCIENCES↗

Targeted inhibition of disheveled PDZ domain via NSC668036 depresses fibrotic process

In this study, we determined the effects of transforming growth factor-beta (TGF-β) and Wnt/β-catenin signaling on myofibroblast differentiation of NIH/3T3 fibroblasts in vitro and evaluated the therapeutic efficacy of NSC668036 in bleomycin-induced pulmonary fibrosis murine model. In vitro study, NSC668036, a small organic inhibitor of the PDZ domain in Dvl, suppressed β-catenin-driven gene transcription and abolished TGF-β1-induced migration, expression of collagen I and α-smooth muscle actin (α-SMA) in fibroblasts. In vivo study, we found that NSC668036 significantly suppressed accumulation of collagen I, α-SMA, and TGF-β1 but increased the expression of CK19, Occludin and E-cadherin that can inhibit pulmonary fibrogenesis. Because fibrotic lung exhibit aberrant activation of Wnt/β-catenin signaling, these data collectively suggest that inhibition of Wnt/β-catenin signaling at the Dvl level may be an effective approach to the treatment of fibrotic lung diseases. - Highlights: • NSC668036 inhibited the proliferation and migration of NIH/3T3 fibroblasts. • NSC668036 suppressed the Wnt/β-catenin signaling pathway. • TGF-β-induced stimulation of profibrotic responses were inhibited by NSC668036. • NSC668036 can inhibit the development of bleomycin-induced pulmonary fibrosis.

60 APPLIED LIFE SCIENCES↗

Aberrant miR-21 and miR-200b expression and its pro-fibrotic potential in hypertrophic scars

The post-traumatic hypertrophic scar (HS) is a fibrotic disease with excessive extracellular matrix (ECM) production by fibroblasts in response to tissue injury. Although dysregulation of miRNAs is known to be involved in a variety of pathophysiologic processes, the role of miRNA in hypertrophic scar formation is unclear. Abnormal expression of miRNA in fibrosis has been investigated in several studies. The transforming growth factor β1 (TGF-β1) promotes fibroblasts proliferation, the synthesis of collagen and other extracellular matrix, and ultimately leads to the formation of the HS by inducing excessive deposition of ECM. We identified two miRNAs whose expression was correlated with fibrotic diseases: miR-21 and miR-200b. This study further confirmed that after stimulation with TGF-β1, the expression of miR-21 was increased, whereas the mRNA level of SMAD7 was decreased in fibroblasts. TGF-β1 reduced the expression of miR-200b, while it augmented that of Zinc finger E-box-binding homeobox 1(Zeb1). Our experiments demonstrated that the expression of miR-21 and miR-200b are related to a disorder, and the TGF-β/miR-21/Smad7 and TGF-β/miR200b/Zeb1 pathways might participate in the pathogenesis of HS. Thus, a novel, beyond the traditional methods, approach for HS treatment via miRNA therapeutics could have been provided. - Highlights: • HS tissue had increased expression of miR-21 and decreased expression of Smad7, lower expression of miR-200b and higher expression of Zeb1. • TGF-β1 downregulated Smad7, which was correlated with the upregulation of miR-21. • TGF-β1 upregulated Zeb1, which was correlated with the downregulation of miR-200b. • miR-200b decreased the expression of Col1A1,Col3A1, Fn, and α-SMA, as well as that of the target Zeb1. • The miR-21 inhibitor decreased expression of Col1A1, Col3A1, Fn, and α-SMA and increased the expression of Smad7.

60 APPLIED LIFE SCIENCES↗

A revisited concept: Contact inhibition of growth. From cell biology to malignancy

In cell biology, contact inhibition refers to two different but closely related phenomena, contact inhibition of locomotion and contact inhibition of proliferation, exhibited by fibroblasts when in contact with one another. Normal fibroblasts migrate across the surface of a culture dish until they make contact with a neighboring cell. Further cell migration is then inhibited, and normal cells adhere to each other, forming an orderly array of cells on the culture dish surface. Tumor cells, in contrast, continue moving after contact with their neighbors, migrating over adjacent cells, and growing in disordered, multilayered patterns. Not only the movement but also the proliferation of many normal cells is inhibited by cell-cell contact, and cancer cells are characteristically insensitive to such contact inhibition. - Highlights: • Contact inhibition refers to contact inhibition of locomotion and of proliferation. • Normal fibroblasts migrate across a culture dish until they make contact with a neighboring cell. • Tumor cells, in contrast, continue moving after contact with their neighbors.

60 APPLIED LIFE SCIENCES↗

Evaluating the efficiency of touch-spun scaffolds in producing dense cell cultures for tissue engineering applications

Developing efficient scaffolds for long-term cell cultivation remains a challenge in tissue engineering. Biomimetic approaches aim to create a three-dimensional (3D) extracellular matrix (ECM)-like fiber network with a tunable hierarchical structure to promote sufficient cell attachment, differentiation, and overall viability. Among the fiber fabrication methods documented in the literature, mechanical fiber drawing techniques, such as touch-spinning, have garnered significant research interest. This is due to the simplicity of the equipment, the ability to control fiber diameter and interfiber spacing at the nanoscale without the need for external fields, and the absence of specific requirements for material dielectric properties. Despite the advantages of mechanically drawn scaffolds in biomedical research, the methodologies for cell culturing and analysis for these materials have not been adequately addressed. In this study, we assess the potential of touch-spun scaffolds in promoting NIH/3T3-GFP fibroblast cell growth for tissue engineering applications. Polycaprolactone/polyethylene oxide (PCL/PEO)-based fiber arrays with a controlled interfiber spacing of 91.9 ± 25.0 μm (N = 50) were fabricated using a modified touch-spinning apparatus and then assembled into 2D and 3D scaffolds through additive manufacturing technology. A comparative cell analysis conducted for single- and multi-layered structures showed that the 3D touch-spun scaffolds support healthy growth of up to 6.5 million fibroblast cells within 21 days and offer enhanced cell viability compared to conventional 2D fiber scaffolds, as confirmed by the Presto Blue assay. Furthermore, the metabolic activity of fibroblasts on 3D scaffolds assessed by the MTT test is approximately four times higher than that of the positive control, making the 3D touch-spun materials ideal for long-term cell culture applications.

Peranidze, Kristina [University of Georgia, Athens↗

Activated KCNQ1 channel promotes fibrogenic response in hereditary gingival fibromatosis via clustering and activation of Ras

Abstract Background and Objective Activated potassium channels were found to be strongly correlated with gingival overgrowth (GO) phenotype as we reviewed syndromic hereditary gingival fibromatosis (HGF). Nevertheless, the functional roles of potassium channels in gingival fibrosis or gingival overgrowth remained uncovered. The aim of the present study was to explore the pathogenic role of aberrantly activated potassium channel in Hereditary Gingival Fibromatosis (HGF). Methods Gingival tissues were collected from 9 HGF patients and 15 normal controls. Expression of KCNQ1 was detected by immunohistochemistry. Gingival fibroblasts were isolated, and outward K + currents were detected by whole‐cell patch‐clamp analysis, transmembrane potential was determined by flow cytometry. Normal human gingival fibroblasts (NHGFs) were transfected with KCNQ1 adenovirus or treated with KCNQ1 selective agonist ML277 and antagonist chromanol 293B. Accumulation of Extracellular Matrix (ECM) was measured by Western blotting and Sircol Soluble Collagen Assay. Content of secreted TGF‐β1 was measured by ELISA. Active RAS pull‐down assay and cell immunofluorescence were utilized to verify RAS activation. Results KCNQ1 was upregulated in gingival tissues derived from HGF patients and HGF gingival fibroblasts presented increased outward K + currents than NHGFs. Overexpression of KCNQ1, or KCNQ1 agonist ML277, promoted fibrotic responses of NHGFs. TGF‐β1 and KCNQ1 channels formed a positive feed‐back loop. ML277 generated lateral clustering and activation of Ras on plasma membrane, followed by augmented MAPK/AP‐1 signaling pathway output. JNK or ERK1/2 inhibitors suppressed ML277‐induced AP‐1 and ECM upregulation. Conclusion Activation of KCNQ1 potassium channel promoted fibrogenic responses in NHGFs via Ras/MAPK/AP‐1 signaling.

Gao, Qian↗

ALDH1A1 Deficiency in Gorlin Syndrome Suggests a Central Role for Retinoic Acid and ATM Deficits in Radiation Carcinogenesis

We hypothesize that aldehyde dehydrogenase 1A1 (ALDH1A1) deficiency will result in impaired ataxia-telangiectasia mutated (ATM) activation in a retinoic acid-sensitive fashion. Data supporting this hypothesis include (1) reduced ATM activation in irradiated primary dermal fibroblasts from ALDH1A1-deficient Gorlin syndrome patients (GDFs), relative to ALDH1A1-positive normal human dermal fibroblasts (NHDFs) and (2) increased ATM activation by X-radiation in GDFs pretreated with retinoic acid, however, the impact of donor variability on ATM activation in fibroblasts was not assessed and is a prudent consideration in future studies. Clonogenic survival of irradiated cells showed differential responses to retinoic acid as a function of treatment time. Long-term (5 Day) retinoic acid treatment functioned as a radiosensitizer and was associated with downregulation of ATM protein levels. Short-term (7 h) retinoic acid treatment showed a trend toward increased survival of irradiated cells and did not downregulate ATM protein levels. Using a newly developed IncubATR technology, which defines changes in bulk chemical bond patterns in live cells, we can discriminate between the NHDF and GDF phenotypes, but treatment of GDFs with retinoic acid does not induce reversion of bulk chemical bond patterns associated with GDFs toward the NHDF phenotype. Collectively, our preliminary investigation of the Gorlin phenotype has identified deficient ALDH1A1 expression associated with deficient ATM activation as a possible susceptibility factor that is consistent with the high incidence of spontaneous and radiation-induced carcinogenesis in these patients. The IncubATR technology exhibits sufficient sensitivity to detect phenotypic differences in live cells that may be relevant to radiation health effects.

59 BASIC BIOLOGICAL SCIENCES↗

Fibrotic activity quantified in serum by measurements of type III collagen pro-peptides can be used for prognosis across different solid tumor types

Due to activation of fibroblast into cancer-associated fibroblasts, there is often an increased deposition of extracellular matrix and fibrillar collagens, e.g. type III collagen, in the tumor microenvironment (TME) that leads to tumor fibrosis (desmoplasia). Tumor fibrosis is closely associated with treatment response and poor prognosis for patients with solid tumors. To assure that the best possible treatment option is provided for patients, there is medical need for identifying patients with high (or low) fibrotic activity in the TME. Measuring unique collagen fragments such as the pro-peptides released into the bloodstream during fibrillar collagen deposition in the TME can provide a non-invasive measure of the fibrotic activity. Based on data from 8 previously published cohorts, this review provides insight into the prognostic value of quantifying tumor fibrosis by measuring the pro-peptide of type III collagen in serum of a total of 1692 patients with different solid tumor types and discusses the importance of tumor fibrosis for understanding prognosis and for potentially guiding future drug development efforts that aim at overcoming the poor outcome associated with a fibrotic TME.

59 BASIC BIOLOGICAL SCIENCES↗

Design, synthesis, and cytostatic activity of novel pyrazine sorafenib analogs

The current study is focused on a series of sorafenib analogs as potential antitumor agents. We have designed and synthesized nine novel pyrazine analogs 6a–i differing in amide and/or urea regions. Two alternative strategies for the preparation of title compounds were applied. The first strategy involved ether formation between 4-hydroxyphenyl urea 3 and 5-chloro-pyrazine-2-carboxamides 4. In the second strategy, ether functionality was introduced in the molecule before urea moiety and included preparation of 5-(4-aminophenoxy)-N-alkylpyrazine-2-carboxamides 5 and their reaction with 4-chloro-3-(fluoromethyl)phenyl isocyanate. Cytostatic activity of the title compounds was evaluated in vitro against a panel of cancer cell lines. Most of the tested compounds showed strong antiproliferative activity in the low micromolar range. 5-/4-[3-(4-chloro-3-trifluoromethyl-phenyl)-ureido]-phenoxy/-pyrazine-2-carboxylic acid (4-chloro-3-trifluoromethylphenyl)-amide (6g) was the most active compound (IC{sub 50} 0.9–7.5 μM) and showed comparable or stronger activity than sorafenib, but also similar cytotoxicity to normal human fibroblast cells. Two compounds, namely, 5-/4-[3-(4-bromophenyl)-ureido]-phenyloxy/-pyrazine-2-carboxylic acid cyclopentylamide (6c) and 5-/4-[3-(4-chloro-3-trifluoromethyl-phenyl)-ureido]-phenoxy/-pyrazine-2-carboxylic acid cyclopentylamide (6h), exerted cytostatic activities that surpassed the effects observed with sorafenib in three cancer cell lines (HepG2, HeLa, A549, IC{sub 50} 0.6–0.9 μM). Similar to sorafenib, compound 6h proved to be cytotoxic to normal human fibroblast cells, whereas compound 6c did not diminish proliferative capacity of these cells and could be regarded as the most promising derivative. Additional biological studies on the c-Raf activity using Western blot method revealed that antiproliferative activity of 6h could be at least partially attributed to its inhibitory effect on c-Raf activation similar to sorafenib. In contrast, 6c did not inhibit the activity of c-Raf, which implies that other cell signaling pathways govern its antiproliferative effects. Taking into account structural differences between compounds 6c and 6h, it is plausible to believe that the substituent in urea part of the molecule is essential for the interaction with c-Raf.

60 APPLIED LIFE SCIENCES↗

Emulsifying and Cell Proliferative Abilities of the Exopolysaccharide Produced by Leguminous Plant Nodule Associated Bacterium Cronobacter sp

Exopolysaccharides (EPS) produced by bacteria are high molecular weight secondary metabolites having wide applications in food and pharmaceutical industry. In the present study, an exopolysaccharide producing bacterium was isolated from the root nodules of a leguminous plant and was studied for emulsification activity and biocompatibility using human dermal fibroblasts. Under optimum culture conditions, the purified EPS yield in modified YEM media was 2.8 g L{sup −1} and was identified as β-glucan with the molecular weight 15.57 × 10{sup 6} Da. The EPS showed high emulsifying activity against hydrocarbons such as petrol, kerosene, xylene, palm oil, coconut oil, and olive oil with emulsification index > 60% at 0.25 and 0.5% concentrations at 25 °C. The EPS was sensitive to high temperature, but the emulsions were stable at pH range 2–9 and in the salinity range of 1–20%. In vitro cell viability studies indicated that EPS was not cytotoxic at tested concentrations on human dermal fibroblasts moreover, it had proliferative activities. Hence, the EPS from Cronobacter sp. can be a good candidate for biotechnological application as a source of β-glucan with emulsifying and tissue regenerative properties.

60 APPLIED LIFE SCIENCES↗

Biochemical characterization of nuclear receptors for vitamin D{sub 3} and glucocorticoids in prostate stroma cell microenvironment

Highlights: {yields} Fibroblasts from benign and carcinoma-associated stroma were biochemically characterized for VDR and GR function as transcription factors in prostate stroma cell microenvironment. {yields} Decreased SRC-1/CBP coactivators recruitment to VDR and GR may result in hormone resistance to 1,25D{sub 3} in stromal cell microenvironment prostate cancer. {yields} 1a,25-Dyhidroxyvitamin D{sub 3} (1,25D{sub 3}) and glucocorticoids, either alone or in combination, may not be an alternative for 'some' advanced prostate cancers that fails androgen therapies. -- Abstract: The disruption of stromal cell signals in prostate tissue microenvironment influences the development of prostate cancer to androgen independence. 1{alpha},25-Dihydroxyvitamin D{sub 3} (1,25D{sub 3}) and glucocorticoids, either alone or in combination, have been investigated as alternatives for the treatment of advanced prostate cancers that fails androgen therapies. The effects of glucocorticoids are mediated by the intracellular glucocorticoid receptor (GR). Similarly, the effect of 1,25D{sub 3} is mediated by the 1,25D{sub 3} nuclear receptor (VDR). In this study, fibroblasts from benign- (BAS) and carcinoma-associated stroma (CAS) were isolated from human prostates to characterize VDR and GR function as transcription factors in prostate stroma. The VDR-mediated transcriptional activity assessed using the CYP24-luciferase reporter was limited to 3-fold induction by 1,25D{sub 3} in 9 out of 13 CAS (70%), as compared to >10-fold induction in the BAS clinical sample pair. Expression of His-tagged VDR (Ad-his-VDR) failed to recover the low transcriptional activity of the luciferase reporter in 7 out of 9 CAS. Interestingly, expression of Ad-his-VDR successfully recovered receptor-mediated induction in 2 out of the 9 CAS analyzed, suggesting that changes in the receptor protein itself was responsible for decreased response and resistance to 1,25D{sub 3} action. Conversely, VDR-mediated transcriptional activity was more efficient in 4 out of 13 CAS (30%), as compared to the BAS sample pair. Consistent with the reduced response to 1,25D{sub 3} observed in CAS, chromatin immunoprecipitation (ChIP) assays indicated decreased recruitment of coactivators SRC-1/CBP, without major changes in the recruitment of VDR to the CYP24 promoter. In addition, we observed that GR-mediated transcriptional activity was also altered in CAS, as compared to BAS. Disruption of coactivators SRC-1/CBP recruitment may promote hormone resistance in CaP, and highlights the relevance of molecular diagnosis and drug design in tumor cell microenvironment.

60 APPLIED LIFE SCIENCES↗

Formation of nanofilms on cell surfaces to improve the insertion efficiency of a nanoneedle into cells

Highlights: Black-Right-Pointing-Pointer We examined the insertion efficiency of nanoneedles into fibroblast and neural cells. Black-Right-Pointing-Pointer Nanofilms formed on cell surfaces improved the insertion efficiency of nanoneedles. Black-Right-Pointing-Pointer Nanofilms improved the insertion efficiency even in Y27632-treated cells. -- Abstract: A nanoneedle, an atomic force microscope (AFM) tip etched to 200 nm in diameter and 10 {mu}m in length, can be inserted into cells with the aid of an AFM and has been used to introduce functional molecules into cells and to analyze intracellular information with minimal cell damage. However, some cell lines have shown low insertion efficiency of the nanoneedle. Improvement in the insertion efficiency of a nanoneedle into such cells is a significant issue for nanoneedle-based cell manipulation and analysis. Here, we have formed nanofilms composed of extracellular matrix molecules on cell surfaces and found that the formation of the nanofilms improved insertion efficiency of a nanoneedle into fibroblast and neural cells. The nanofilms were shown to improve insertion efficiency even in cells in which the formation of actin stress fibers was inhibited by the ROCK inhibitor Y27632, suggesting that the nanofilms with the mesh structure directly contributed to the improved insertion efficiency of a nanoneedle.

60 APPLIED LIFE SCIENCES↗