C26 Cells Research Articles

Enriched inhibition of cancer and stem-like cancer cells via STAT-3 modulating niclocelles.

We describe for the first time a therapeutic strategy to target stem-like cancer cells via STAT-3 modulation using a nanomedicine approach. Niclocelle, a niclosamide loaded rigid core mixed micelle, was synthesized from a self-assembled well-defined amphiphilic diblock copolymer and an FDA-approved signal transducer and activator of transcription factor 3. Followed by a rigorous physico-chemical characterization, niclocelles were evaluated biologically for cytotoxicity and apoptosis in human melanoma (C32) and breast cancer (MDA-MB231 and MCF-7) cells. Niclocelles were found to selectively reduce the CD44+ stem cell population in C32 cells via STAT-3 modulation.

Optimizing long-circulating liposomes for delivery of simvastatin to C26 colon carcinoma cells

Simvastatin (SIM) is a lipophilic statin that has potential benefits for prevention and treatment of several types of malignancies. However, its low water solubility and the toxicity associated with administration of high doses recommend it for encapsulation in carriers able to deliver the therapeutic dose in the tumor. In this work, liposomes with long-circulating properties were proposed as delivery systems for SIM. The objective of this study was to optimize the formulation of SIM-loaded long-circulating liposomes (LCL-SIM) by using D-optimal experimental design. The influence of phospholipids concentration, phospholipids to cholesterol molar ratio and SIM concentration was studied on SIM liposomal concentration, encapsulation efficiency and liposomal size. The optimized formulation had liposomal SIM concentration 6238 µg/ml, EE % of 83.4 % and vesicle size of 190.5 nm. Additionally we evaluated the in vitro cytotoxicity of the optimized liposomal SIM (LCL-SIM-OPT) on C26 murine colon carcinoma cells cultivated in monoculture as well as in co-culture with murine peritoneal macrophages at a cell density ratio that provides an approximation of physiological conditions of colon carcinoma development in vivo. Our preliminary studies suggested that LCL-SIM-OPT exerted cytotoxicity on C26 cells probably via enhancement of oxidative stress in co-culture environment.

Treatment of colon cancer by regulatable lentivirus-mediated interleukin-12 gene

Objective To evaluate the efficiency of interleukin-12 (IL-12) gene mediated by RU486 regulatable lentivirus system on tumor growth and microvessel angiogenesis of mouse colon cancer C26 cells subcutaneously implanted tumor.Methods The mouse IL-12 gene was recombined to construct the RU486 regulatable lentivirus transfer plasmid PNL-LV-RUmIL-12.The LV-RUmIL-12 lentiviruses were produced by co-transfecting PNL-LV-RUmIL-12.The expression of IL-12 in C26 colon cancer cells infected by RU486 regulated LV-RUmIL-12 lentivirus was detected by enzyme linked immunosorbent assay (ELISA) kit.Colon cancer model was established by subcutaneously inoculating C26 cells into the BALB/c mice.One hundred mice were divided into 5 groups:PBS group,blank lentivirus group (LV group),RU486 group,LV-RUmIL-12 group and LV-RUmIL-12-RU486 group.The tumor size changes were calculated.After treatment for 21 days,the mice were sacrificed by cervical dislocation.Serum levels of IL-12 were assayed by enzyme linked immunosorbent assay (ELISA).Immunohistochemical staining was employed to determine microvessel density (MVD) and CD4 + and CD8 + lymphocytes in the tumor tissues.Results After injection of LV-RUmIL-12 lentivirus,the expression of IL-12 protein in C26 cells was RU486 dose-dependent.The high-est expression level of IL-12 protein in 1 × 106 C26 cells induced by 1 × 10-5 mol/L RU486 was (148 ± 25) μg/L.Serum levels of IL-12 were (3 572.60 ±245.60),(145.43 ± 13.53),(134.53 ± 12.86),(147.32 ± 15.56) and (139.67 ± 14.84) μg/L in LV-RUmIL-12-RU486,PBS,LV,RU486 and LV-RUmIL-12 groups respectively,and IL-12 level was significantly increased in LV-RUmIL-12-RU486 group (P ＜ 0.05).The tumor growth in LV-RUmIL-12-RU486 group was markedly inhibited.The inhibition rate in LV-RUmIL-12-RU486 group was 72.59％.The MVD in LV-RUmIL-12-RU486 group (12.5 ± 4.3) was statistically decreased as copared with PBS group (45.5 ±5.7),LV group (39.5 ± 3.7),RU486 group (42.4 ±7.5) and LV-RUmIL-12 group (47.2 ±2.6,P＜0.05).AS compared with the control groups,the number of CD4 and CD8 + lymphocytes in tumor tissue of LV-RUmIL-12-RU486 group was significantly reduced (P ＜ 0.05).Conclusion The RU486 regulatable lentivirus containing IL-12 gene can inhibit the growth of transplanted mouse colon cancer in association with a significant reduction in angiogenesis. Key words: Interleukin-12; Colon cancer; Lentivirus; Angiogenesis

In vitro antioxidant and antiproliferative activities of nine Salvia species

Supported by a growing increase of scientific research attesting the health properties of salvia species, we have decided to investigate nine Salvia namely Salvia sclarea, Salvia atropatana, Salvia sahendica, Salvia hydrangea, Salvia xanthocheila, Salvia macrosiphon, Salvia glutinosa, Salvia chloroleuca and Salvia ceratophylla species for their antioxidant and antiproliferative activities. In order to correlate the bioactivity with their phytochemical content, the total phenol and total flavonoid contents were also determined. S. ceratophylla exhibited the strongest activity against C32 cells with an IC50 value of 20.8 μg mL− 1, while S. glutinosa exhibited an IC50 value of 29.5 μg mL− 1 against ACHN cell line. Interestingly, S. glutinosa displayed also the highest DPPH radical-scavenging activity with an IC50 of 3.2 μg mL− 1. These species are characterised by the highest total phenol and flavonoid contents. The obtained results suggest that Salvia species are healthy plant foods.

Upregulation of heme oxygenase-1 in colorectal cancer patients with increased circulation carbon monoxide levels, potentially affects chemotherapeutic sensitivity.

BackgroundHeme oxygenase-1 (HO-1) and its major product carbon monoxide (CO) are known to be involved in the development and progression of many tumors. The present study was to elucidate the expression and function of HO-1 in colorectal cancer (CRC), specially focusing on the circulation CO levels in CRC patients and the possible roles of HO-1 in chemoresistance of colon cancer cells.MethodsOne hundred and eighteen patients received resection for colorectal cancer and polyps at China Medical University Sheng Jing Hospital, were collected in this study. HO-1 expression in CRC tissues was analyzed by immnuohistochemical staining; circulation CO levels as carboxyhemoglobin (COHb) in CRC patients were analyzed by an ABL800 FLEX blood gas analyzer. HO-1 expression in murine colon cells C26 and human colon cancer cells HT29 and DLD1 under HO-1 inducer hemin and anticancer drug pirarubicin (THP) treatment was examined by RT-PCR, and the cell viability after each treatment was investigated by MTT assay. Data were analyzed by student’s t-test or one-way ANOVA followed by Bonferroni t-test or Fisher's exact test.ResultsHO-1 expression in tumor tissues of CRC (61.0%) was significantly higher than in normal colorectal tissues and polyps tissues (29.7%, P < 0.01); well-differentiated CRC seemed to express more HO-1 (81.5%) than moderately/poorly-differentiated cancers (59.5%, P < 0.05). However, the nuclear HO-1 expression is apparently higher in moderately/poorly differentiated CRC than well-differentiated CRC probably suggesting a new mechanism of function involved in HO-1 in cancer. In parallel with HO-1 expression, circulation CO levels in CRC patients also significantly accelerated. Moreover, HO-1 expression/induction also related to the chemosensitivity of colon cells; HO inhibitor zinc protoporphyrin significantly increased cytotoxicities of THP (i.e., 2.6 – 5.3 folds compared to cells without zinc protoporphyrin treatment).ConclusionsThese findings strongly suggested HO-1/COHb is a useful diagnostic and prognostic indicator for CRC, and inhibition of HO-1 may be a option to enhance the chemotherapeutic effects of conventional anticancer drugs toward CRC.

The research of antitumor activities in vitro of DCs loading antigen prouced by radiofrequency ablation of tumor combined with CIK cells

Objective To study the in vitro anti-tumor activity of dendritic cells (DCs) loading with antigen produced by radiofrequency ablation of tumor lysate in situ combined with cytokine-induced killer cells (CIK).Methods CIK ceils derived from BALB/C mouse spleen and DCs derived from bone marrow were prepared,and experimental model of murine colon carcinoma were established for radiofrequency ablation.The supernatant of tumor tissue in situ lysis after repeated freezing and thawing were tested by lowry protein quantitative statutory,amounting to a final concentration of 5 μg/ml,then load to the first 5 days of culture DCs (Ag-DC),2 days later,co-cultured with CIK cells after the first seven days of culture 48 h (Ag-DC-CIK).Flow cytometry was used to analyze costimulatory molecules on the surface of the cells,and CCK-8 assay to detect in vitro cytotoxic activity.Results The DCs loading with antigen resulted in an increase in the proportion of CD86 + CD11 c +,MHC Ⅱ + CD11 c + and MHC Ⅱ + CD80 + cells.The main effector cells of CIK cells were CD3 + NK1.1 + cells.The percentage of CD3 + NK1.1 + cells was 1.45％ on the first day of the culture ; while when they had been cultured for 7 days,the percentage CD3 + NK1.1 + significantly increased to 36.9％.The cytotoxicity of Ag-DC-CIK cells toward C26 cells was much more efficient than that of DC-CIK,CIK cells.The cytotoxic activity of the former was significantly lower than the latter and the same target ratio.When the ratios of effector cells to target cells were 5 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (74.9 ± 3.5) ％,; while the DC-CIK was (71.2 ± 2.1) ％ and the CIK cells was (68.7 ± 2.9) ％.The difference was statistically significant(F =7.007,P =0.007).When the ratios of effector cells to target cells were 10 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (82.3 ± 4.5) ％,while the DC-CIK cells was (77.1 ± 5.1) ％,and the CIK cells was (72.7 ± 2.8) ％.The difference was statistically significant (F =7.727,P =0.005).When the ratios of effector cells to target cells were 20 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (83.2 ± 1.9) ％,while the DC-CIK cells was (77.2 ± 4.2) ％,and the CIK cells was (73.0 ± 2.6) ％.The difference was statistically significant (F =16.594,P =0.000).Conclusion DCs loading with antigen produced by radiofrequency ablation of tumor in situ pyrolysis products can improve in vitro cytotoxic activity combined with CIK cells,which can provide a new comprehensive cancer treatment strategy. Key words: Dendritic cells; Colonic neoplasms; Radiofrequency ablation

In vitro Cancer Cell Growth Inhibition and Antioxidant Activity of Bombax ceiba (Bombacaceae) Flower Extracts

The flowers of Bombax ceiba were investigated for their chemical composition, antioxidant effects and antiproliferative activity against seven human cancer cell lines. The antiproliferative responses of diethyl ether (DE) and light petroleum (PE) extracts were evaluated by sulforhodamine B (SRB) assay against MCF-7, HeLa, COR-L23, C32, A375, ACHN, and LNCaP cells in comparison with a human normal cell line, 142BR. Moreover, extracts were characterized by GC-MS analysis and tested for their antioxidant properties by different in vitro systems, namely DPPH, Fe-chelating activity and beta-carotene bleaching test. Both PE and DE extracts showed the highest antiproliferative activity against human renal adenocarcinoma (ACHN) in a concentration-dependent manner. PE extract showed the highest radical scavenging activity against the DPPH radical, while DE extract was more active in the beta-carotene bleaching test. The presence of beta-sitosterol and some fatty acids may contribute to the bioactivity of B. ceiba flower extracts.

Design and synthesis of anti-cancer cyclopeptides containing triazole skeleton

We describe the design and synthesis of some hypothetical heptapeptides specifically to overcome the neoplastic activity of ras oncogene and their anti-cancer activities were studied. To improve the anti-cancer activity of the synthesized peptides, their structure modifications were done based on a sequential Ugi/Huisgen 1,3-Dipolar cyclization reaction. The cyclopeptides which contained triazole skeleton showed significant anti-cancer activity against cancer cells with mutated ras oncogene such as A549, PC3 and C26 cells. This study clearly shows the importance of triazole skeleton in biological activity of the peptides. It might be possible to overcome the difficulties involved in making complex peptides by employing this elegant chemistry.

Liposomes co-modified with cholesterol anchored cleavable PEG and octaarginines for tumor targeted drug delivery

Tumor targeted drug delivery system with high efficiency of tumor accumulation, cell internalization and endosomal escape was considered ideal for cancer therapy. Herein, a cleavable polyethylene glycol (PEG) and octaarginines (R8) co-modified liposome (CL-R8-LP) was developed, in which the cholesterol was used as an alternative anchor to the commonest phospholipids for the diversified development of surface modification. The in vitro hemolysis assay and bio-distribution study demonstrated that CL-R8-LP improved biocompatibility and tumor accumulation compared with the single R8 modified liposomes (R8-LP), since the strong positive charges, toxicity and non-specificity of R8 were efficiently shielded by the outer cleavable PEG. And the cellular uptake, cytotoxicity and apoptosis of CL-R8-LP on C26 cells were much stronger than that of control liposomes in which R8 was not included or exposed. In addition, it was confirmed that CL-R8-LP entered cells via clathrin-mediated endocytosis and the macropinocytosis, and followed by a more efficient endosomal escape compared with R8-LP due to the topology change of R8. The enhanced in vivo delivery efficiency and anti-tumor efficacy were validated in C26 bearing mice. In conclusion, the results demonstrated that CL-R8-LP was a promising vehicle for enhancing the chemotherapy of solid cancers.

Up-regulation of Axin2 by dexamethasone promotes adipocyte differentiation in ROB-C26 mesenchymal progenitor cells

Dexamethasone (Dex) regulates osteoblastic and adipocytic differentiation in mesenchymal progenitor cells through regulation of Wnt/β-catenin signaling. To elucidate the regulatory mechanisms underlying the effects of Dex, we examine the expression of Axin2, which is an intracellular inhibitor of Wnt/β-catenin signaling, in ROB-C26 clonal mesenchymal progenitor cells (C26). We observed the induction of Axin2 mRNA in C26 cells in response to Dex treatment. Treatment with a glucocorticoid receptor (GR) antagonist, mifepristone, showed that Dex-induced up-regulation of Axin2 is mediated by the GR. In the absence of Dex, gene silencing by using Axin2-targeted short hairpin RNA increased the number of alkaline phosphatase (ALP)-positive and nuclear β-catenin-positive cells and ALP activity. In the presence of Dex, Axin2 knockdown resulted in an increased number of ALP-positive and nuclear β-catenin-positive cells. Furthermore, Axin2 knockdown in Dex-treated cells suppressed adipocyte differentiation (as determined by reduced Oil Red O staining), reduced the number of PPARγ-positive and aP2-positive cells and decreased the mRNA expression of PPARγ2 and aP2. These results suggest that Axin2 plays a key role in adipocyte and osteoblastic differentiation by controlling β-catenin expression.

Anti-inflammatory guaiane-type sesquiterpenes from the fruits of Pittosporum undulatum

Two unprecedented guaiane-type sesquiterpene glycosides (undulatumosides A and B) were isolated by bioassay-guided fractionation from the MeOH extract of Pittosporum undulatum fruits, along with six known compounds, including the guaiane isomers 5-guaien-11-ol and 4-guaien-11-ol. The structures of the compounds were established as 4-guaiene-11-O-β-d-(3'-angeloxy-6'-deoxy)-glucopyranoside and 1(5)-guaiene-11-O-β-d-(3'-angeloxy-6'-deoxy)-glucopyranoside by spectroscopic methods, including 1D and 2D homo- and heteronuclear NMR experiments (COSY, HSQC, HMBC and NOESY), and HR-mass spectrometry. P. undulatum is a highly invasive weed that often outcompetes other plants, yet its fruits have become a traditional anti-inflammatory medicine in Azores. Therefore, aiming to investigate the claimed properties, the in vitro anti-inflammatory activity of guaiane-type sesquiterpenes was evaluated by analyzing their inhibitory effects on chemical mediators released by the LPS activated RAW 264.7 murine macrophages cell line. In addition, the cytotoxicity of these compounds was also evaluated in this cell line. Undulatumoside A, 5-guaien-11-ol and 4-guaien-11-ol displayed anti-inflammatory activity with IC50 values of 16.4, 8.1 and 7.2μM, respectively, comparable to that of the positive control, indomethacin (IC50=18.2 μM), with no cytotoxic effects (IC50 ≥ 198 μM). Furthermore, the same set of compounds was also assessed for anti-proliferative activity in lung large cell carcinoma COR-L23 and amelanotic melanoma C32 cells.

Epirubicin loaded super paramagnetic iron oxide nanoparticle-aptamer bioconjugate for combined colon cancer therapy and imaging in vivo

Every year a large number of new cases of colorectal cancer are diagnosed in the world. Application of Epirubicin (Epi) in treatment of cancer has been limited due to its cardiotoxicity. Specific delivery of chemotherapy drugs is an important factor in reducing the side effects of drugs used in chemotherapy. Enhanced permeability, retention effect and magnetic resonance (MR) traceability of super paramagnetic iron oxide nanoparticles (SPION) make them a great candidate in cancer therapy and imaging. In this study, Epirubicin-5TR1 aptamer–SPION tertiary complex was evaluated for the imaging and treatment of murine colon carcinoma cells (C26 cells, target). For cytotoxic studies (MTT assay), C26 and CHO-K1 (Chinese hamster ovary cells, nontarget) cells were treated with either Epi or Epi–Apt–SPION tertiary complex. Internalization was evaluated by flow cytometry. Finally, Apt-SPION bioconjugate was used for imaging of cancer in vivo. Flow cytometric analysis showed that the tertiary complex was internalized effectively to C26 cells, but not to CHO-K1 cells. Cytotoxicity of Epi–Apt–SPION tertiary complex also confirmed internalization data. The complex was less cytotoxic in CHO-K1 cells when compared to Epi alone. No significant change in viability between Epi- and complex-treated C26 cells was observed. Magnetic resonance imaging (MRI) indicated a high level of accumulation of the nano-magnets within the tumor site. In conclusion Epi–Apt–SPION tertiary complex is introduced as an effective system for targeted delivery of Epi to C26 cells. Moreover this complex could efficiently detect tumors when analyzed by MRI and inhibit tumor growth in vivo.

Determination of deltonin in rat plasma by using HPLC–MS/MS and the application of this method in pharmacokinetic studies

Deltonin is a naturally occurring spirostanol glycoside from Dioscorea zingiberensis C.H. Wright, which is used in traditional Chinese medicine. It exerts strong cytotoxic effect on C26 cells, inhibits C26 derived-tumor growth, and prolongs the survival of tumor-bearing mice after its oral administration, indicating its potential for use as an anti-tumor drug. To investigate the pharmacokinetic profiles of deltonin, a rapid, sensitive, and simplified high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay was developed and validated for the determination of deltonin in rat plasma. After acetonitrile-mediated plasma protein precipitation, chromatographic separation of deltonin was achieved using a reversed phase Hypersil Gold column (150mm×2.1mm, 5μm), with gradient elution using 0.1% formic acid and acetonitrile. Thereafter, deltonin was quantified using MS/MS with electrospray ionization (ESI) in positive multiple reaction monitoring (MRM) mode. The flow rate of the mobile phase was 200μL/min, and the retention time was 9.03min for deltonin and 6.31min for the internal standard (IS: 20(S)-ginsenoside Rb1). The linear range of the calibration curve was 2-5000ng/mL (r(2)>0.99), and the limit of detection (LOD) was 0.46ng/mL. The intra- and inter-day accuracies ranged from -2.8% to 11.1% and precisions (RSD) were within 13.1%. Deltonin was found to be stable under short-term temperature conditions, post-preparative temperature conditions, and after 3 freeze-thaw cycles conditions. The validated method was successfully applied to a pharmacokinetic study in rats after oral administration of deltonin (50 and 100mg/kg). The pharmacokinetics is characterized by high apparent clearance (CL/F) and apparent volume of distribution (Vd/F).

The Role of Versican in Modulating Breast Cancer Cell Self-renewal

Versican is highly expressed during the early stages of tissue development and its expression is elevated during wound repair and tumor growth. There is little literature on the potential role of breast cancer stem cells on the cellular-extracellular matrix interactions involving versican. An anti-versican short hairpin RNA (shRNA) was used to observe the effect of reduction of versican on breast cancer self-renewal. A versican G3 construct was exogenously expressed in breast cancer cell lines. Colony formation and mammosphere formation assays were conducted; flow cytometry was applied to analyze the prevalence of side population cells. The versican G3- and vector-transfected 66c14 cells were injected transdermally into BALB/c mice as a 10-fold dilution series from 1 × 10(5) to 1 × 10(2) cells per mouse. Versican G3 domain enhanced breast cancer self-renewal in both experimental in vitro and in vivo models. Versican G3-transfected cells contained high levels of side population cells, formed more mammospheres when cultured in the serum-free medium, and formed a greater number and larger colonies. Reduction of versican's functionality through anti-versican shRNA or knocking out the EGF-like motifs reduced the effect of versican on enhancing mammosphere and colony formation. Versican-enhanced self-renewal played a role in enhanced chemotherapeutic drug resistance, relating partly to the upregulated expression of EGF receptor (EGFR) signaling. Versican is highly expressed in breast cancer progenitor cells and was maintained at high levels before cell differentiation. Overexpression of versican enhanced breast cancer self-renewal through EGFR/AKT/GSK-3β (S9P) signaling and conferred resistant to chemotherapeutic drugs tested.

Antiproliferative Activities on Renal, Prostate and Melanoma Cancer Cell Lines of Sarcopoterium spinosum Aerial Parts and its Major Constituent Tormentic Acid

The search for improved cytotoxic agents continues to be an important line in the discovery of modern anticancer drugs. Sarcopoterium spinosum (L.) Spach is mentioned in ethnobotanical surveys as a medicinal plant used for the treatment of cancer. The aim of this study is to investigate and to compare the aerial parts of S. spinosum collected in Italy and Lebanon for their chemical composition and their antiproliferative activity against ACHN, C32, A375, MCF-7, LNCaP and HeLa human cancer cell lines using SRB assay. The main constituent tormentic acid was isolated by MPLC and characterized by spectroscopic techniques (NMR, MS). Non polar compounds were analyzed by GC and GC-MS. S. spinosum showed an interesting antiproliferative activity against ACHN and C32 cell lines with IC(50) values of 2.4 and 2.7 μg/ml for S. spinosum from Italy and Lebanon, respectively. Remarkable results were obtained also against A375 and LNCaP cell lines. The cytotoxicity against ACHN cell line could be partially attributed to tormentic acid that demonstrated a higher cytotoxicity than the positive control vinblastine. Close association between the radical scavenging activity (evaluated by DPPH and ABTS assay) and cytotoxicity was also demonstrated. This investigation demonstrated the potential cytotoxic activity of S. spinosum taking into account also that none of the tested extracts, fractions and isolated compound affected the proliferation of normal cell line 142BR. Tormentic acid, the major constituent isolated from S. spinosum, play an important role in the cytotoxicity exhibited by the extract.

Development of new therapeutic antibodies formats directed against the folate receptor alpha.

Event Abstract Back to Event Development of new therapeutic antibodies formats directed against the folate receptor alpha. Davide Bernareggi1, Elena Luison1, Alessandro Satta1, Barbara Frigerio1, Silvana Canevari1 and Mariangela Figini1* 1 Fondazione IRCCS - Istituto Nazionale dei Tumori, Italy In our laboratory two monoclonal antibodies (Abs) directed against the folate receptor alpha (FRα), MOv18 and MOv19 were discovered, providing the foundation upon which to build new human Abs. Using phage display technology were developed fully human Fab fragments with the same specificity of the murine Ab MOv19 and two of them, AFRA4 and AFRA5.3 were later engrafted in complete immunoglobulins. These new reagents were assessed for binding properties and specificity on FRα and epithelial ovarian cancer cell lines. AFRA complete antibodies of IgG1 and IgE isotype were compared with ChiMOv19 for their binding properties and the IgG1 for the ability to enhance the effectors functions, as evaluated by antibody dependent cell-mediated cytotoxicity (ADCC) assays. Enhancement of ADCC on high FRα expressing cells, comparable to that of ChiMOv19, was observed for AFRA Abs despite their reduced binding affinity and different binding kinetics. The complete human structure could be probably more efficient in inducing ADCC, balancing the reduced binding activity. In order to assess the effects in vivo in immunocompetent mouse models we built “reverse chimeric” (RC) forms of AFRA, composed of human Fabs and murine Fc and we assessed the RC AFRA5.3 IgG2A in two immunocompentent mouse models. In the first model C26 cells expressing human FRα were injected subcutaneusly but, although we noticed a trend in reducing tumor growth by AFRA, we encountered problems with control mice. Therefore we shifted to a transgenic immunocompetent mouse model which expresses FRα on breast cancer cells and experiments are ongoing. Acknowledgements This work was supported in part by the European project Magnifyco (Contract NMP4-SL-2009-228622) Keywords: ovarian cancer, Antibody engineering, Folate receptor alpha, tumor immunology, Human antibody Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Translational immunology and immune intervention Citation: Bernareggi D, Luison E, Satta A, Frigerio B, Canevari S and Figini M (2013). Development of new therapeutic antibodies formats directed against the folate receptor alpha.. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00803 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 18 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Mariangela Figini, Fondazione IRCCS - Istituto Nazionale dei Tumori, Milan, Italy, mariangela.figini@istitutotumori.mi.it Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Davide Bernareggi Elena Luison Alessandro Satta Barbara Frigerio Silvana Canevari Mariangela Figini Google Davide Bernareggi Elena Luison Alessandro Satta Barbara Frigerio Silvana Canevari Mariangela Figini Google Scholar Davide Bernareggi Elena Luison Alessandro Satta Barbara Frigerio Silvana Canevari Mariangela Figini PubMed Davide Bernareggi Elena Luison Alessandro Satta Barbara Frigerio Silvana Canevari Mariangela Figini Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Synthesis, characterization and biological studies of diosgenyl analogues

A series of optical amino acid diosgenyl esters and diosgenyl salicylate conjugates were designed and synthesized to develop new anticancer and anti-inflammatory agents. The analogue 9c that contains an 6-aminohexanoic acid residue at C-3 of diosgenin exhibits higher potency against all three tumor cell lines with IC50 values ranging from 4.7μM in C26 cells to 14.6μM in Hep G2 cells. In addition, seven of newly synthesized compounds significantly inhibit xylene-induced ear edema and exhibit comparable or better anti-inflammatory activities than those of diosgenin and aspirin. Furthermore, preliminary structure–activity relationship studies demonstrate that diosgenyl salicylate conjugates have stronger anti-inflammatory activities than amino acid diosgenyl esters.

Inhibition of Wnt/β-catenin signaling by dexamethasone promotes adipocyte differentiation in mesenchymal progenitor cells, ROB-C26

Dexamethasone (Dex) stimulates the differentiation of mesenchymal progenitor cells into adipocytes and osteoblasts. However, the mechanisms underlying Dex-induced differentiation have not been clearly elucidated. We examined the effect of Dex on the expression and activity of Wnt/β-catenin signal-related molecules in a clonal mesenchymal progenitor cell line, ROB-C26 (C26). Dex induced the mRNA expression of Wnt antagonists, dickkopf-1 (Dkk-1), and Wnt inhibitory factor (WIF)-1. Immunocytochemical analysis showed that the downregulation of β-catenin protein expression by Dex occured concomitantly with the increased expression of the PPARγ protein. Dex decreased phosphorylation of Ser9-GSK3β and expression of active β-catenin protein. To examine the effects of Dex on Wnt/β-catenin activity, we used immunocytochemistry to analyze TCF/LEF-mediated transcription during Dex-induced adipogenesis in Wnt indicator (TOPEGFP) C26 cells. Our results demonstrated that Dex repressed TCF/LEF-mediated transcription, but induced adipocyte differentiation. Treatment with a GSK3β inhibitor attenuated Dex-induced inhibition of TCF/LEF-mediated transcriptional activity, but suppressed Dex-induced adipocyte differentiation, indicating that adipocyte differentiation and inhibition of Wnt/β-catenin activity by Dex are mediated by GSK3β activity. Furthermore, β-catenin knockdown not only suppressed Dex-induced ALP-positive osteoblasts differentiation but also promoted Dex-induced adipocytes differentiation. These results suggest that inhibition of β-catenin expression by Dex promotes the differentiation of mesenchymal progenitor cells into adipocytes.

The role of versican G3 domain in regulating breast cancer cell motility including effects on osteoblast cell growth and differentiation in vitro– evaluation towards understanding breast cancer cell bone metastasis

BackgroundVersican is detected in the interstitial tissues at the invasive margins of breast carcinoma, is predictive of relapse, and negatively impacts overall survival rates. The versican G3 domain is important in breast cancer cell growth, migration and bone metastasis. However, mechanistic studies evaluating versican G3 enhanced breast cancer bone metastasis are limited.MethodsA versican G3 construct was exogenously expressed in the 66c14 and the MC3T3-E1 cell line. Cells were observed through light microscopy and viability analyzed by Coulter Counter or determined with colorimetric proliferation assays. The Annexin V-FITC apoptosis detection kit was used to detect apoptotic activity. Modified Chemotactic Boyden chamber migration invasion assays were applied to observe tumor migration and invasion to bone stromal cells and MC3T3-E1 cells. Alkaline phosphatase (ALP) staining and ALP ELISA assays were performed to observe ALP activity in MC3T3-E1 cells.ResultsIn the four mouse breast cancer cell lines 67NR, 66c14, 4T07, and 4T1, 4T1 cells expressed higher levels of versican, and showed higher migration and invasion ability to MC3T3-E1 cells and primary bone stromal cells. 4T1 conditioned medium (CM) inhibited MC3T3-E1 cell growth, and even lead to apoptosis. Only 4T1 CM prevented MC3T3-E1 cell differentiation, noted by inhibition of alkaline phosphatase (ALP) activity. We exogenously expressed a versican G3 construct in a cell line that expresses low versican levels (66c14), and observed that the G3-expressing 66c14 cells showed enhanced cell migration and invasion to bone stromal and MC3T3-E1 cells. This observation was prevented by selective EGFR inhibitor AG1478, selective MEK inhibitor PD 98059, and selective AKT inhibitor Triciribine, but not by selective JNK inhibitor SP 600125. Versican G3 enhanced breast cancer cell invasion to bone stromal cells or osteoblast cells appears to occur through enhancing EGFR/ERK or AKT signaling. G3 expressing MC3T3-E1 cells showed inhibited cell growth and cell differentiation when cultured with TGF-β1 (1 ng/ml), and expressed enhanced cell apoptosis when cultured with TNF-α (2 ng/ml). Enhanced EGFR/JNK signaling appears to be responsible for G3 enhanced osteoblast apoptosis and inhibited osteoblast differentiation. Whereas repressed expression of GSK-3β (S9P) contributes to G3 inhibited osteoblast growth. Versican G3 functionality was dependent on its EGF-like motifs. Without the structure of EGF-like repeats, the G3 domain would not confer enhancement of tumor cell migration and invasion to bone with concordant inhibition of osteoblast differentiation and promotion of osteoblast apoptosis.ConclusionsVersican enhances breast cancer bone metastasis not only through enhancing tumor cell mobility, invasion, and survival in bone tissues, but also by inhibiting pre-osteoblast cell growth, differentiation, which supply favorable microenvironments for tumor metastasis.

Myostatin is a novel tumoral factor that induces cancer cachexia

Humoral and tumoral factors collectively promote cancer-induced skeletal muscle wasting by increasing protein degradation. Although several humoral proteins, namely TNFα (tumour necrosis factor α) and IL (interleukin)-6, have been shown to induce skeletal muscle wasting, there is a lack of information regarding the tumoral factors that contribute to the atrophy of muscle during cancer cachexia. Therefore, in the present study, we have characterized the secretome of C26 colon cancer cells to identify the tumoral factors involved in cancer-induced skeletal muscle wasting. In the present study, we show that myostatin, a procachectic TGFβ (transforming growth factor β) superfamily member, is abundantly secreted by C26 cells. Consistent with myostatin signalling during cachexia, treating differentiated C2C12 myotubes with C26 CM (conditioned medium) resulted in myotubular atrophy due to the up-regulation of muscle-specific E3 ligases, atrogin-1 and MuRF1 (muscle RING-finger protein 1), and enhanced activity of the ubiquitin–proteasome pathway. Furthermore, the C26 CM also activated ActRIIB (activin receptor type II B)/Smad and NF-κB (nuclear factor κB) signalling, and reduced the activity of the IGF-I (insulin-like growth factor 1)/PI3K (phosphoinositide 3-kinase)/Akt pathway, three salient molecular features of myostatin action in skeletal muscles. Antagonists to myostatin prevented C26 CM-induced wasting in muscle cell cultures, further confirming that tumoral myostatin may be a key contributor in the pathogenesis of cancer cachexia. Finally, we show that treatment with C26 CM induced the autophagy–lysosome pathway and reduced the number of mitochondria in myotubes. These two previously unreported observations were recapitulated in skeletal muscles collected from C26 tumour-bearing mice.