NIH 3T3 Fibroblasts Research Articles

Extracellular Microenvironmental Change by B16F10 Melanoma-derived Proteins Induces Cancer Stem-like Cell Properties from NIH3T3 Cells

Cancer stem-like cells (CSCs) can generate solid tumors through the properties of stem cells such as self-renewal and differentiation and they cause drug resistance, metastasis and recurrence. Therefore, establishing CSC lines is necessary to conduct various studies such as on the identification of CSC origin and specific targeted therapies. In this study, we stimulated NIH3T3 fibroblasts to exhibit the characteristics of CSCs using the whole protein lysates of B16F10 melanoma cells. As a result, we induced colony formation that displayed self-renewal and differentiation capacities through anchorage-independent culture and re-attached culture. Moreover, colonies showed drug resistance by being maintained in the G0/G1 state. Colonies expressed various CSC markers and displayed high-level drug efflux capacity. Additionally, colonies clearly demonstrated tumorigenic ability by forming a solid tumor in vivo. These results show that proteins of cancer cells could transform normal cells into CSCs by increasing expression of CSC markers. This study argues the tremendous importance of the extracellular microenvironmental effect on the generation of CSCs. It also provides a simple experimental method for deriving CSCs that could be based on the development of targeted therapy techniques.

Functionally modified magnetic nanoparticles for effective siRNA delivery to prostate cancer cells in vitro.

Different types of siRNA delivery vehicles including nanoparticles have been synthesized and utilized for prostate cancer gene therapy. However, one of the most common limitations being faced is the toxicity of cationic polymers toward the cells. In the current study, magnetic nanoparticles were prepared and conjugated with cationic polymer, polyethylenimine. Then polyethylene glycol was conjugated with polyethylenimine to improve the biocompatibility of nanoparticles. The transmission electron microscopy size of nanoparticles was found to be 15.82 (±9.07) nm, while hydrodynamic size was about 79.20 (±0.68) nm. Zeta potential analysis of polyethylenimine and polyethylene glycol-coated nanoparticles was +31.4 (±0.62) and +5.65 (±0.76) mV, respectively. Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance confirmed the presence of polyethylene glycol and polyethylenimine polymers in magnetic nanoparticles. Cell viability test in mouse fibroblast NIH 3T3 and prostate cancer PC3 cells showed an increased in biocompatibility of functionally modified polyethylene glycol–polyethylenimine–Fe3O4 nanoparticles. siRNA targeting a disintegrin and metalloproteinase 10 (ADAM10) was successfully loaded into the polyethylene glycol–polyethylenimine–Fe3O4 nanoparticles and delivered to PC3 cells. The results clearly demonstrated a significant decrease in cell viability, which increased within a certain siRNA concentration. The inhibitory concentration (IC50) value for ADAM10 siRNA was calculated to be 15.83 nM after 72 h. Confocal microscopy confirmed the delivery of siRNA-loaded nanoparticles intracellularly to the tumor cells cytosol. This magnetic system can be used as a powerful platform to inhibit cancer cells progression.

Co-encapsulation of magnetic Fe3O4 nanoparticles and doxorubicin into biocompatible PLGA-PEG nanocarriers for early detection and treatment of tumours

At present, cancer is the first cause of death for humans, but early detection and treatment can help improve prognoses and reduce mortality. However, further development of carrier-assistant drug delivery systems (DDSs) is retarded by the aspects such as the low drug-carrying capacity, carrier-induced toxicity and immunogenicity, complex synthesis manipulation. The development of nanoscale drug delivery systems (NDDS) have been rapidly developed to address these issues. In this article, we used PLGA-PEG with good biocompatibility to encapsulate Fe3O4 nanoparticles (a magnetic resonance imaging contrast agent) and DOX (an antitumour drug) via the emulsion-solvent evaporation method, aimed at achieving a dual function of the early detection and the treatment of mammary cancer. The results showed that the Fe3O4/DOX/PLGA-PEG nanoparticles had a relatively uniform size, a high carrier rate of Fe3O4 and high encapsulation efficiency of DOX, and a relatively high activity of released DOX within 120 h. In addition, in vitro studies showed that the Fe3O4/DOX/PLGA-PEG nanoparticles were cytocompatibility in NIH 3T3 fibroblast cells culture study while had a special effect on destroying human breast cancer MCF-7 cells compared with pure DOX solution. In vitro studies revealed that the Fe3O4/DOX/PLGA-PEG enabled enhanced T2 contrast magnetic resonance. Overall, our multifunctional Fe3O4/DOX/PLGA-PEG nanoparticles, composed of biocompatible substances and therapeutic/imaging materials, have great potential for the early detection of cancer and accurate drug delivery via the dynamic monitoring using MRI.

Water Extract of Cryphaea heteromalla (Hedw.) D. Mohr Bryophyte as a Natural Powerful Source of Biologically Active Compounds.

Bryophytes comprise of the mosses, liverworts, and hornworts. Cryphaea heteromalla, (Hedw.) D. Mohr, is a non-vascular lower plant belonging to mosses group. To the date, the most chemically characterized species belong to the liverworts, while only 3.2% and 8.8% of the species belonging to the mosses and hornworts, respectively, have been investigated. In this work, we present Folin–Ciocalteu and oxygen radical absorbance capacity (ORAC) data related to crude extracts of C. heteromalla obtained by three different extraction solvents: pure water (WT), methanol:water (80:20 v/v) (MET), and ethanol:water (80:20 v/v) (ETH). The water extract proved to be the best solvent showing the highest content of biophenols and the highest ORAC value. The C. heteromalla-WT extract was investigated by HPLC-TOF/MS (High Performance Liquid Chromatography-Time of Flight/Mass Spectrometry) allowing for the detection of 14 compounds, five of which were phenolic compounds, derivatives of benzoic, caffeic, and coumaric acids. Moreover, the C. heteromalla WT extract showed a protective effect against reactive oxygen species (ROS) generation induced by tert-butyl hydroperoxide (TBH) on the murine NIH-3T3 fibroblast cell line.

Andrographolide ameliorates bleomycin-induced pulmonary fibrosis by suppressing cell proliferation and myofibroblast differentiation of fibroblasts via the TGF-β1-mediated Smad-dependent and -independent pathways

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with no effective medication. Andrographolide (Andro), extracted from Chinese herbal Andrographis paniculata, could attenuate bleomycin (BLM)-induced pulmonary fibrosis via inhibition of inflammation and oxidative stress, however, the anti-fibrotic mechanisms have not been clarified. Myofibroblasts are the primary cell types responsible for the accumulation of extracellular matrix (ECM) in fibrotic diseases, and targeting fibroblast proliferation and differentiation is an important therapeutic strategy for the treatment of IPF. Hence, this study aimed to investigate the effects of Andro on the fibroblast proliferation and differentiation in the in vivo and in vitro models. The results showed that Andro improved pulmonary function and inhibited BLM-induced fibroblast proliferation and differentiation and ECM deposition in the lungs. In vitro, Andro inhibited proliferation and induced apoptosis of TGF-β1-stimulated NIH 3T3 fibroblasts and primary lung fibroblasts (PLFs). Andro also inhibited TGF-β1-induced myofibroblast differentiation and ECM deposition in both cells. We also found that Andro suppressed TGF-β1-induced Smad2/3 and Erk1/2 activation, suggesting that Smad2/3 and Erk1/2 inactivation mediates Andro-induced effects on TGF-β1-induced fibroblast proliferation and differentiation. These results indicated that Andro has novel and potent anti-fibrotic effects in lung fibroblasts via inhibition of the proliferation and myofibroblast differentiation of fibroblasts and subsequent ECM deposition, which are modulated by TGF-β1-mediated Smad-dependent and -independent pathways.

Characterization of a nontoxic pyomelanin pigment produced by the yeast Yarrowia lipolytica.

In this study, we report on the ability of the yeast Yarrowia lipolytica W29 to produce an extracellular melanin-like brown pigment at high yield (0.5 mg/ml) in culture medium supplemented with L-tyrosine. This pigment has been characterized as pyomelanin and its synthesis was found to occur by the so-called HGA-melanin pathway. The purified pyomelanin was found embedded with antioxidant properties as it exhibited a radical scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 of 230 μg/ml. It was also characterized as noncytotoxic toward two mammalian cell lines, namely the mouse fibroblast NIH3T3 and human keratinocytes HaCaT. When blended with different commercial sunscreens, the purified pyomelanin increased significantly the sun protection factor (SPF) value, highlighting its potential utilization as UV-filter in cosmetic preparations.

The transcription factor MZF1 differentially regulates murine Mtor promoter variants linked to tumor susceptibility

Mechanistic target of rapamycin (MTOR) is a highly conserved serine/threonine kinase that critically regulates cell growth, proliferation, differentiation, and survival. Previously, we have implicated Mtor as a plasmacytoma-resistance locus, Pctr2, in mice. Here, we report that administration of the tumor-inducing agent pristane decreases Mtor gene expression to a greater extent in mesenteric lymph nodes of BALB/cAnPt mice than of DBA/2N mice. We identified six allelic variants in the Mtor promoter region in BALB/cAnPt and DBA/2N mice. To determine the effects of these variants on Mtor transcription, we constructed a series of luciferase reporters containing these promoter variants and transfected them into mouse plasmacytoma cells. We could attribute the differences in Mtor promoter activity between the two mouse strains to a C → T change at the -6 position relative to the transcriptional start site Tssr 40273; a T at this position in the BALB promoter creates a consensus binding site for the transcription factor MZF1 (myeloid zinc finger 1). Results from electrophoretic mobility shift assays and DNA pulldown assays with ChIP-PCR confirmed that MZF1 binds to the cis-element TGGGGA located in the -6/-1 Mtor promoter region. Of note, MZF1 significantly and differentially down-regulated Mtor promoter activity, with MZF1 overexpression reducing Mtor expression more strongly in BALB mice than in DBA mice. Moreover, MZF1 overexpression reduced Mtor expression in both fibroblasts and mouse plasmacytoma cells, and Mzf1 knockdown increased Mtor expression in BALB3T3 and NIH3T3 fibroblast cells. Our results provide evidence that MZF1 down-regulates Mtor expression in pristane-induced plasmacytomas in mice.

Stabilization of chitosan-polyethylene oxide electrospun nanofibrous containing Colocasia esculenta tuber protein

In this study, protein in Colocasia esculenta tuber (CET) combined with polyethylene oxide (PEO) and chitosan were fabricated by electrospinning, which could be further stabilized by heat treatment and compared with glutaraldehyde vapor. CET’s protein containing 6.6% protein with molecular weight 53.5, 42, 24.4, 11.8, and 9.8 kDa shows no cytotoxicity and has the potential growth-stimulatory activities on NIH-3T3 fibroblast cell. The 10% (v/v) acetic acid was found as an appropriate solvent to electrospun the CET’s protein-chitosan-PEO solution. The influence of conductivity, surface tension, and viscosity in the solution of CET’s protein, chitosan, and PEO on nanofibers morphology was successfully demonstrated. The scanning electron microscope shows that the average diameter of the CET’s protein-chitosan-PEO nanofibers decreased with the increased of chitosan and CET’s protein content. The chemical and physical stabilization of nanofibers exhibits an increase in the fiber diameter up to 157%. The presence of 1% (w/v) chitosan resulted in a better preservative of the nanofibrous structure after the stabilization process. By the confirmation using Fourier transform infrared spectroscopic data, it is concluded that stabilization techniques applied in this study are promising to improve the value of CET’s protein-chitosan-PEO nanofiber in medical purposes.

A 3D Heterotypic Multicellular Tumor Spheroid Assay Platform to Discriminate Drug Effects on Stroma versus Cancer Cells.

Three-dimensional (3D) cell culture models are thought to mimic the physiological and pharmacological properties of tissues in vivo more accurately than two-dimensional cultures on plastic dishes. For the development of cancer therapies, 3D spheroid models are being created to reflect the complex histology and physiology of primary tumors with the hopes that drug responses will be more similar to and as predictive as those obtained in vivo. The effect of additional cell types in tumors, such as stromal cells, and the resulting heterotypic cell-cell crosstalk can be investigated in these heterotypic 3D cell cultures. Here, a high-throughput screening-compatible drug testing platform based on 3D multicellular spheroid models is described that enables the parallel assessment of toxicity on stromal cells and efficacy on cancer cells by drug candidates. These heterotypic microtissue tumor models incorporate NIH3T3 fibroblasts as stromal cells that are engineered with a reporter gene encoding secreted NanoLUC luciferase. By tracking the NanoLUC signal in the media over time, a time-related measurement of the cytotoxic effects of drugs on stromal cells over the cancer cells was possible, thus enabling the identification of a therapeutic window. An in vitro therapeutic index parameter is proposed to help distinguish and classify those compounds with broad cytotoxic effects versus those that are more selective at targeting cancer cells.

Anti-inflammatory effect of epidermal growth factor conjugated silk fibroin immobilized polyurethane ameliorates diabetic burn wound healing

Few studies are reported on immunomodulatory potential of non-mulberry (Antheraea mylitta) silk fibroin (SF) combined with polyurethane (PU) in diabetic wound healing. In this study, PU/SF (Antheraea mylitta) scaffolds were fabricated by blending and immobilization techniques. Effective SF dosage was determined and incorporated according to minimum inhibitory concentrations against wound associated bacterial strains while fabricating scaffold. Dermal fibroblast NIH3T3 cells were seeded on epidermal growth factor (EGF) treated and untreated PU/SF scaffolds, fabricated by blending and immobilization techniques. Fibroblast seeded PU/SF scaffolds were investigated for anti-inflammatory response in wound recovering potential comparing with Acticoat™ in third degree burn of streptozotocin induced diabetic rats. At 16th, 24th days, promising healing was achieved with faster granulation, enhanced collagenization, patterned re-epithelialization by EGF treated cellular immobilized PU/SF in normal, hyperglycemic burn. Biomarkers of different healing stages, CD31 (haemostasis), Ki67 (proliferative), alpha-sma, COL III (maturation) were examined. Since hyperglycemic burn is characterized by inflated pro-inflammatory cytokines, serum, tissue IL-6,8,10 were recorded, which revealed timely restoration of inflated IL-6,8 and protection against IL-10 elevation by cellular immobilized PU/SF compared to Acticoat™ (p ≤ 0.05), control (p ≤ 0.01). E-cadherin (gap junction protein), MMP 9 response suggested anti-inflammatory role of PU/SF on accelerated healing of thermal injury as potent dermal substitute.

Characterization and Analysis of Collective Cellular Behaviors in 3D Dextran Hydrogels with Homogenous and Clustered RGD Compositions.

The interactions between substrate materials and cells usually play an important role in the hydrogel-based 3D cell cultures. However, the hydrogels that are usually used could not be parametrically regulated, especially for quantitatively regulating the spatial distribution of the adhesion sites for cells in 3D. Here, we employed the semisynthetic hydrogel consisting of maleimide-dextran, Arg-Gly-Asp (RGD) peptides, and cell degradable crosslinkers to biochemically characterize the evolutionary behaviors of NIH–3T3 fibroblasts and C2C12 cells in 3D. Moreover, by comparing the cell-adhesive efficacy of 3D dextran hydrogels with four different RGD clustering rates, we explored the underlying regulation law of C2C12 connections and 3T3 aggregations. The results showed that mal-dextran hydrogel could promise cells stable viability and continuous proliferation, and induce more self-organized multicellular structures relative to 2D culture. More importantly, we found that RGD-clustered mal-dextran hydrogel has the advantage of enhancing C2C12 cell elongation and the breadthwise-aggregated connection, and promoting the 3T3 cell aggregating degree compared to that with homogenous RGD. Further, the advantages of RGD clustering hydrogel could be amplified by appropriately reducing RGD concentration. Such RGD-composition controllable mal-dextran hydrogel can function as a regulator of the collective cellular behaviors, which provides useful information for quantitatively designing the tailored hydrogel system and exploiting advanced biomaterials.

Protective Effects of Ginseng Proteins on Photoaging of Mouse Fibroblasts Induced by UVA.

UVA can penetrate dermis and cause functional damage of dermal fibroblasts leading photoaging. Ginseng is a widely used traditional Chinese medicine for skin aging. However, its effects on skin photoaging induced by UVA are not clear. In this study, we isolated ginseng proteins (GP), with molecular weights of 27 kDa and 13 kDa, and found that they alleviated the inhibitory effects of UVA on cell viability and increased percentage of NIH-3T3 fibroblasts in the S phase of cells cycle. GP also improved cell contraction ability, increased the expression and secretion of CoL-I, similar to MAPK phosphorylation inhibitors and reduced expression and secretion of MMP-1, MMP-2 and MMP-9 as well as the enzyme activities of MMP-2 and MMP-9. They reduced ROS content, DNA damage and 8-OHdG content, as well as the protein expression of p53, p21 and p16. The levels of p-ERK, p-p38 and p-JNK, p-c-Fos and p-c-Jun proteins were decreased by GP. Inactivated GP did not inhibit the cellular activity and expression and secretion of CoL-I irradiated by UVA. The results showed that GP can improve cell viability and contractile function by inhibiting DNA damage and collagen degradation to inhibit the photoaging effects of skin dermal cells caused by UVA.

---Successful Application of Whole Cell Panning for Isolation of Phage Antibody Fragments Specific to Differentiated Gastric Cancer Cells.

Purpose: Generation of antibodies which potentially discriminate between malignant and healthy cells is an important prerequisite for early diagnosis and treatment of gastric cancer (GC). Comparative analysis of cell surface protein landscape will provide an experimental basis for biomarker discovery, which is essential for targeted molecular therapies. This study aimed to isolate phage-displayed antibody fragments recognizing cell surface proteins, which were differently expressed between two closely related GC cell lines, namely AGS and MKN-45. Methods: We selected and screened a semisynthetic phage-scFv library on AGS, MKN-45, and NIH-3T3 cell lines by utilizing a tailored selection scheme that was designed to isolate phagescFvs that not only recognize the differentiated AGS cells but also distinguish them from NIH3T3 fibroblasts and the poorly differentiated MKN-45 cells. Results: After four rounds of subtractive whole cell panning, 14 unique clones were identified by ELISA screening and nucleotide sequencing. For further characterization, we focused on four phage-scFvs with strong signals in screening, and their specificity was confirmed by cell-based ELISA. Furthermore, the selected phage-scFvs were able to specifically stain AGS cells with 38.74% (H1), 11.04% (D11), 76.93% (G11), and 69.03% (D1) in flow cytometry analysis which supported the ability of these phage scFvs in distinguishing AGS from MKN-45 and NIH-3T3 cells. Conclusion: Combined with other proteomic techniques, these phage-scFvs can be applied to membrane proteome analysis and, subsequently, identification of novel tumor-related antigens mediating proliferation and differentiation of cells. Furthermore, such antibody fragments can be exploited for diagnostic purposes as well as targeted drug delivery of GC.

Mediating the Migration of Mesenchymal Stem Cells by Dynamically Changing the Density of Cell-selective Peptides Immobilized on β-Cyclodextrin-modified Cell-resisting Polymer Brushes

Dynamic control of mesenchymal stem cell (MSC) behaviors on biomaterial surface is critically involved in regulating the cell fate and tissue regeneration. Herein, a stimuli-responsive surface based on host-guest interaction with cell selectivity was developed to regulate migration of MSCs in situ by dynamic display of cell-specific peptides. Azobenzene-grafted MSC-affinitive peptides (EPLQLKM, Azo-E7) were grafted to β-cyclodextran (β-CD)-modified poly(2-hydroxyethyl methacrylate)-b-poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) (PHG) brushes, which were prepared by using surface-initiated atom transfer radical polymerization (SI-ATRP). X-ray photoelectron spectroscopy (XPS), quartz crystal microbalance (QCM), and water contact angle were used to characterize their structure and property. Cell adhesion assay showed that the combination effect of resisting property of PHG and MSC-affinity of E7 could promote the selective adhesion of MSCs over other types of cells such as RAW264.7 macrophages and NIH3T3 fibroblasts to some extent. UV-Vis spectroscopy proved that the competing guest molecules, amantadine hydrochloride (Ama), could release Azo-E7 peptides from the CD surface to different extents, and the effect was enhanced when UV irradiation was employed simultaneously. As a result, the decrease of cell adhesion density and migration rate could be achieved in situ. The cell density and migration rate could be reduced by over 40% by adding 20 μmol/L Ama, suggesting that this type of surface is a new platform for dynamic regulation of stem cell behaviors in situ.

EFFECT OF LATEX FROM MUSA PARADISIACA VAR. SAPIENTUM AND CARICA PAPAYA L. ON PROLIFERATION AND MIGRATION FIBROBLAST CELL NIH3T3

Objective: The objective of this research was to screen phytochemical constituents and determine the activity of latex from Musa paradisiacavar. sapientum and Carica papaya L. to the process of wound healing in NIH3T3 fibroblasts cells through observations of the proliferation andmigration of cells.Materials and Methods: Screening phytochemical compounds of latex from M. paradisiaca var. sapientum and C. papaya L. used chemical reagent.Cytotoxic activity using 3-(4,5-dimethylthiazol-2-yl)-2.5-diphenyl tetrazolium bromide (MTT) method. The proliferation test used the doubling timemethod at a susceptible incubation time of 0, 24, 48, and 72 h with a concentration of 25 μg/mL–250 μg/mL. The migration test was carried out usingthe scratch wound healing method with a concentration of 25 μg/mL–250 μg/mL in the time range of 0, 12, 24, and 48 h.Results: Phytochemical compounds contained in the latex from M. paradisiaca var. sapientum (saponin and tannin) and C. papaya L. (saponin andalkaloid). The cytotoxic assay results showed that no toxic effect for NIH3T3 fibroblasts cells (IC50 >1000 μg/mL). Cell proliferation and migrationtest results showed an increase in NIH3T3 fibroblast cell proliferation and migration process compared to controls. The concentration of 250 μg/mLof latex from M. paradisiaca var. sapientum and C. papaya L. is the best to increase of proliferation and migration process of NIH3T3 fibroblast cells.Conclusion: This study concludes that the latex of M. paradisiaca var. sapientum and C. papaya L. has the potential to increase proliferation andmigration activity of NIH3T3 cells.

FACTOR PROMOTING WOUND HEALING: RADICAL SCAVENGING AND ANTI-INFLAMMATORY ACTIVITY AND GROWTH FACTOR PROMOTION OF HELIOTROPIUM INDICUM

Objective: This study aims to investigate the effects of the Heliotropium indicum extract (HIE) on factor promoting wound healing in radical scavengingand inflammatory activity and growth factor promotion.Methods: The radical scavenging capacity of HIE was evaluated by scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) radicals.Furthermore, the anti-inflammatory of HIE was determined in a cellular model. RAW264.7 macrophage cells were treated with various concentrationsof HIE before activating the treated cell with lipopolysaccharide (LPS). The nitrite concentration of activated macrophage was determined by the Griessreagent kit. The cell viability of RAW264.7 was evaluated by resazurin reduction assay as well as NIH3T3 fibroblast cells. In addition, production of thegrowth factors (transforming growth factor-β [TGF-β] and basic fibroblast growth factor [bFGF]) of fibroblast was determined by Elisa kit.Results: HIE exhibited radical scavenging activity in the DPPH and NO radicals with half maximal inhibitory concentration (IC50) at 0.22 mg/ml and0.52 mg/ml, respectively. In a cellular study, HIE inhibited NO production in LPS-stimulated macrophage without cytotoxic effect to the cells with IC50at 87 μg/ml. Furthermore, HIE promoted fibroblast cell viability at 72 h of treatment and, TGF-β and bFGF production at 24 h of treatment.Conclusion: These results obtained in this study suggested that HIE promoted the factors which involved in wound healing processes, including antiinflammatoryeffect with scavenged radical forming and inhibited activated-macrophage. Furthermore, HIE also stimulated growth factor productionin fibroblast. These finding supported using traditional and folk medicine of H. indicum in wound treatment.

Success and efficiency of cell seeding in Avian Tendon Xenografts – A promising alternative for tendon and ligament reconstruction

Decellularized tendon xenografts offer a promising alternative for reconstruction by using ubiquitously available material. This study compares static and centrifugal seeding of avian tendon scaffolds with NIH 3T3 fibroblasts. Incorporation of viable cells was achievable with both techniques, represented by DNA content. Proliferation rate and viability assay showed neither damage by centrifugal force nor superiority of the technique. Cell proliferation after 10 days of culture demonstrated that the scaffold did not hinder 3-D culturing. Confocal laser microscopy revealed structural details as formation of focal adhesions, to provide deeper insight into the process of cell attachment and growth in xenografts.

Cyclic stretch-induced mechanical stress to the cell nucleus inhibits ultraviolet radiation-induced DNA damage.

Ultraviolet (UV) radiation exerts adverse effects on genome stability, alters the normal state of life, and causes several diseases by inducing DNA damage. Although mechanical stimulation such as stretching has significant effects on the prevention and treatment of diseases, its influence on nuclear morphology and/or intranuclear functions involving resistance to DNA damage remains unknown. Here, we investigated the effects of mechanical stimulation by cyclic stretching on nuclear morphology and resistance of DNA to UV damage in NIH3T3 fibroblasts. Adherent cells on silicone elastic membranes were subjected to ~ 10% cyclic uniaxial stretch at a frequency of 0.5Hz for 12h. As a result, the intracellular actin cytoskeleton and nucleus were found to be elongated and aligned in the direction of zero normal strain (~ 62° with respect to the stretch direction) in an actomyosin tension-dependent manner. The nuclei of the stretched cells were dramatically compressed by the reorganized actin stress fibers located on their apical and both sides, and a significant increase in the intranuclear DNA density was observed. Intercellular tension, as assessed with live cell atomic force microscopy imaging, also increased following exposure to cyclic stretch. The UV radiation-induced DNA damage, estimated from the fluorescence intensity of the phospho-histone γ-H2AX, significantly decreased in these stretched cells. These results indicate that the cyclic stretch-induced morphological changes in the nucleus may improve the UV radiation resistance of cells, probably owing to the intracellular force-induced condensation of chromatin. To our knowledge, this is the first study to demonstrate the inhibition of the UV radiation-induced DNA damage by mechanical stimulation.

Newly identified LMO3-BORCS5 fusion oncogene in Ewing sarcoma at relapse is a driver of tumor progression

Recently, we detected a new fusion transcript LMO3-BORCS5 in a patient with Ewing sarcoma within a cohort of relapsed pediatric cancers. LMO3-BORCS5 was as highly expressed as the characteristic fusion oncogene EWS/FLI1. However, the expression level of LMO3-BORCS5 at diagnosis was very low. Sanger sequencing depicted two LMO3-BORCS5 variants leading to loss of the functional domain LIM2 in LMO3 gene, and disruption of BORCS5. In vitro studies showed that LMO3-BORCS5 (i) increases proliferation, (ii) decreases expression of apoptosis-related genes and treatment sensitivity, and (iii) downregulates genes involved in differentiation and upregulates proliferative and extracellular matrix-related pathways. Remarkably, in vivo LMO3-BORCS5 demonstrated its high oncogenic potential by inducing tumors in mouse fibroblastic NIH-3T3 cell line. Moreover, BORCS5 probably acts, in vivo, as a tumor-suppressor gene. In conclusion, functional studies of fusion oncogenes at relapse are of great importance to define mechanisms involved in tumor progression and resistance to conventional treatments.

The SNPs in myoD gene from normal muscle developing individuals have no effect on muscle mass

BackgroundMyogenic Differentiation 1 (MyoD) is a crucial master switch in regulating muscle-specific gene transcription. Forced expression of myoD is equipped to induce several cell lineages into myoblast, which then differentiate and fuse into myotube. Pig is one of the most significant livestock supplying meat, and has been classified into lean, fat and miniature pig breeds. However, the mechanisms underlying muscle mass variation among different pig breeds have remained unclear. Considering the important effect of MyoD on muscle development, it remains to be investigated whether the difference in muscle mass is caused by its single nucleotide polymorphisms (SNPs) which are the major differences among pig breeds at DNA level.ResultsIn this study, we identified the locations of porcine myoD regulatory regions including proximal regulatory region (PRR), distal regulatory region (DRR), and core enhancer (CE) region. There are 8 SNPs in the regulatory regions and 6 SNPs in gene body region, which were identified from lean, fat and miniature pig populations. However, these SNPs have no effects on its temporal expression and transcriptional activity which might lead to the distinction in postnatal muscle mass. In addition, overexpression of myoD clones across from amphibious to mammals including xenopus tropicalis, chicken, mouse and pig whose gene identities vary from 68 to 84%, could promote myogenesis in NIH3T3 fibroblasts cells.ConclusionsThese results proved that myoD nucleotide variations from different pig populations have no effect on muscle mass, suggesting that the function of myoD is highly conserved not only among different pig breeds, but also across different species. Thus, it would be futile to discover SNPs affecting muscle mass in pig populations with normal muscle development.