Mutation analysis using cell-free DNA for endocrine therapy in patients with HR+ metastatic breast cancer.

We prospectively evaluated the utility of ESR1 and PIK3CA mutation analysis with cell-free DNA (cfDNA) using droplet digital PCR (ddPCR) for the efficacy of endocrine therapy (ET) in hormone receptive positive (HR+) metastatic breast cancer (MBC) patients. CfDNA was analyzed just before the start of ET for MBC. E380Q, Y537N, Y537S, and D538G were assessed for ESR1 mutations and H1047R, E545K, and E542K were assessed for PIK3CA mutations. A total of 75 patients were enrolled. Of those, 31 (41.3%) received letrozole with palbociclib, and 28 (37.3%) received exemestane and everolimus (EverX). ESR1 mutations were found in 36 (48.0%) patients, of which 16 (21.3%) had more than one variant. Seventeen (23.6%) patients had one PIK3CA mutation and 8 (11.1%) had two. In the total population, time to progression of the first ET after enrollment (TTP1) decreased significantly as the number of ESR1 mutations increased (p < 0.001). PIK3CA mutations were also significantly associated with shorter TTP1 (median TTP1: 16.2 months vs. 10.9 months, p = 0.03). In contrast, PIK3CA mutations were significantly associated with longer TTP in patients receiving EverX treatment (median TTP of EverX: 15.9 months vs. 5.2 months, p = 0.01) and remained a significant factor in multivariable analysis for TTP of EverX in this subgroup (hazard ratio = 0.2, 95% CI = 0.1- 0.8, p = 0.03). ESR1 and PIK3CA mutations in cfDNA were associated with clinical efficacies of ET in HR+ MBC patients.

Anti-tumor activity of BET inhibitors in androgen-receptor-expressing triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a heterogeneous disease comprising several subtypes. Androgen-receptor (AR) signaling has been targeted by several investigational agents in luminal AR subtype TNBCs. Bromodomain (BRD) and extra-terminal motif (BET) protein inhibitors have been shown to attenuate AR signaling in metastatic castration-resistant prostate cancer and to overcome enzalutamide resistance. We demonstrated potent anti-tumor effects of the BET inhibitor JQ1 against AR-positive TNBC cell lines using cell viability and cell cycle analysis. To reveal the mechanisms of JQ1 effects, multiplex gene expression analysis and immunoblotting assays were used. We examined in vivo effects of JQ1 in a xenograft model of AR expressing TNBC. JQ1 exhibited its anti-proliferative activity by inducing apoptosis and cell cycle arrest. JQ1 activity was not mediated by MYC downregulation. Instead, JQ1 blocked the interactions among the ATPase-family AAA-domain-containing 2 protein (ATAD2), BRD2, BRD4, and AR; effectively suppressing the expression of AR associated targets. In addition, JQ1 showed significant anti-tumor activity in vivo in TNBC xenograft mouse models as a monotherapy and in combination with anti-AR therapy. Taken together, our results showed that the BET inhibitor JQ1 is a promising therapeutic agent for the treatment of AR-positive TNBC.

Tumor-derived IL-18 induces PD-1 expression on immunosuppressive NK cells in triple-negative breast cancer.

PURPOSE: While the inflammatory cytokine interleukin-18 (IL-18) is known to activate natural killer (NK) cells, its precise role in cancer is controversial. In this study, we investigated the role of tumor-derived IL-18 on peripheral blood NK cells in breast cancer patients. RESULTS: In breast cancer cell lines, IL-18 was expressed and secreted in the triple-negative breast cancer (TNBC) cell lines MDA-MB-231 and HCC-70 but not in MCF-7 cells. The immature and non-cytotoxic CD56dimCD16dim/- NK cell fraction was increased following co-culture with MDA-MB-231 cells, and this increase was not observed with tumor cells transfected with siRNA for IL-18 or in MCF-7 cells. In addition, tumor-derived IL-18 increased PD-1 expression on CD56dimCD16dim/- NK cells, although no effect on PD-L1 expression in tumor cells was observed. Among EBC patients, serum IL-18 levels were significantly increased in those with a TNBC subtype compared to levels from patients with other subtypes, and the IL-18 levels were strongly associated with poor survival. Similarly, serum IL-18 and CD56dimCD16dim/- NK cells were also increased in patients with metastatic TNBC who had progressive disease following cytotoxic chemotherapy. EXPERIMENTAL DESIGN: We performed in vitro experiments in breast cancer cell lines, measured cytokine levels by RT-qPCR, western blot, and ELISA, and analyzed NK cell subsets by flow cytometry. For clinical validation, we collected and analyzed blood sample from patients with early breast cancer (EBC, N = 545) and metastatic breast cancer (MBC, N = 42). CONCLUSIONS: Our data revealed that tumor-derived IL-18 is associated with bad prognosis in patients with TNBC. Tumor-derived IL-18 increased the immunosuppressive CD56dimCD16dim/- NK cell fraction and induced PD-1 expression on these NK cells.

Neoangiogenesis of human mesenchymal stem cells transfected with peptide-loaded and gene-coated PLGA nanoparticles.

Several factors are involved in angiogenesis. To form new blood vessels, we fabricated vehicles carrying an angiogenesis-related peptide (apelin) and gene (vascular endothelial growth factor (VEGF)165) that were internalized by human mesenchymal stem cells (hMSCs). These non-toxic poly-(DL)-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) easily entered hMSCs without cytotoxicity. The negatively charged outer surface of PLGA NPs can be easily complexed with highly positively charged polyethylenimine (PEI) to deliver genes into cells. PLGA NPs complexed with PEI could be coated with negatively charged VEGF plasmid DNA and loaded with apelin. The physical characteristics of these PLGA NPs were determined by size distribution, gel retardation, and morphological analyses. Transfection of VEGF-coated apelin-loaded PLGA NPs resulted in the differentiation of hMSCs into endothelial cells and vascular formation in Matrigel in vitro. Following injection of hMSCs transfected with these PLGA NPs into an ischemic hind limb mouse model, these cells differentiated into endothelial cells and accelerated neovascularization.

Neurogenesis Is Induced by Electrical Stimulation of Human Mesenchymal Stem Cells Co-Cultured With Mature Neuronal Cells.

For electrical stimulation of hMSCs, gold nanoparticles were coated onto polyethyleneimine coated glass cover slips. The effects of pulsed or constant electrical stimulation upon cytotoxicity and differentiation of hMSCs were examined. The effects of co culturing hMSCs with neuronal cells were also tested. The neuronal differentiation of the stem cells was evaluated by determining the expression of neuron-specific genes and proteins using RT-PCR and Western blotting. Morphological changes were evaluated by scanning electron microscopy. The hMSCs co-cultured with mature neuronal cells and stimulated with electrical shock showed the greatest level of neurite outgrowth (>150 mm) and smaller cell body sizes.

Carboxymethylcellulose (CMC) formed nanogels with branched poly(ethyleneimine) (bPEI) for inhibition of cytotoxicity in human MSCs as a gene delivery vehicles.

Specific vehicles are necessary for safe and efficient gene transfection into cells. Nano-type hydrogels (nanogel) comprising carboxymethylcellulose (CMC) complexed with branched type cationic poly(ethleneimine) (bPEI) were used as gene delivery vehicles. When complexes of CMC and bPEI were used in vitro, CMC showed nano-gel type properties, as shown by the results of a viscosity test, and bPEI showed low cytotoxicity comparing to bPEI alone. Together, these properties are shown to maintain high gene transfection efficiency. In viability experiments using three types of adult stem cells, cell viability varied depending on the branch form of PEI and whether or not it is in a complex with CMC. The gene delivery efficacy showed that the CMC nanogel complexed with bPEI (CMC-bPEI) showed more uptaking and gene transfection ability in hMSCs comparing to bPEI alone. In osteogenesis, the CMC-bPEI complexed with OSX pDNA showed more easy internalization than bPEI alone complexed with OSX pDNA in hMSCs. Specific genes and proteins related in osteogenic differentiation were expressed in hMSCs when the CMC-bPEI complexed with OSX pDNA was used.

The effect of quantum dot size and poly(ethylenimine) coating on the efficiency of gene delivery into human mesenchymal stem cells.

Quantum dot (QDs) have been employed as bioimaging agents and delivery vehicles for gene therapeutics in several types of cells. In this study, we fabricated multiple QD bundled nanoparticles (NPs) to investigate the effect of QD size and poly(ethylenimine) (PEI) coating on the efficiency of gene delivery into human mesenchymal stem cells (hMSCs). Several types of QDs, which exhibit different ranges of particle size and fluorescence when employed, were coated with PEI to alter their negative charges and to enable them to be bundled into larger particles. Using specific wavelengths of QDs for bioimaging, gene-complexed QD bundled NPs were easily detected in the hMSCs using several different methods such as fluorescence-activated cell sorter, confocal laser scanning microscopy, and in vivo optical imaging. These PEI-coated, bundled QD NPs exhibited significantly higher gene transfection efficacy than single-type QDs. Particularly, the largest QD bundled NPs examined, QD655, had a much higher uptake capability and greater gene expression ability than the other QD NPs (QD525, QD565, and QD605). We believe that our findings help to enrich knowledge of design considerations that will aid in the engineering of QD NPs for stem cell application in the future.

Co-delivery of Cbfa-1-targeting siRNA and SOX9 protein using PLGA nanoparticles to induce chondrogenesis of human mesenchymal stem cells.

During stem cell differentiation, various cellular responses occur that are mediated by transcription factors and proteins. This study evaluated the abilities of SOX9, a crucial protein during the early stage of chondrogenesis, and siRNA targeting Cbfa-1, a transcription factor that promotes osteogenesis, to stimulate chondrogenesis. Non-toxic poly-(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. Coomassie blue staining and circular dichroism revealed that the loaded SOX9 protein maintained its stability and bioactivity. These NPs easily entered human mesenchymal stem cells (hMSCs) in vitro and caused them to differentiate into chondrocytes. Markers that are typically expressed in mature chondrocytes were examined. These markers were highly expressed at the mRNA and protein levels in hMSCs treated with PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. By contrast, these cells did not express osteogenesis-related markers. hMSCs were injected into mice following internalization of PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. When the injection site was excised, markers of chondrogenesis were found to be highly expressed at the mRNA and protein levels, similar to the in vitro results. When hMSCs internalized these NPs and were then cultured in vitro or injected into mice, chondrogenesis-related extracellular matrix components were highly expressed.

Multi-modal transfection agent based on monodisperse magnetic nanoparticles for stem cell gene delivery and tracking.

Directing the controlled differentiation and tracking of stem cells is essential to achieve successful stem cell therapy. In this work, we describe a multi-modal (MR/optical) transfection agent (MTA) for efficient gene delivery and cell tracking of human mesenchymal stem cells (hMSCs). The MTA was synthesized through a facile two-step approach with 1) ligand exchange of a catechol-functionalized polypeptide (CFP) and 2) chemical immobilization of fluorescence labelled cationic polymer via aminolysis reaction. Cationic polymer-immobilized MTAs with size of ~40 nm exhibit greatly enhanced colloidal stability in aqueous solution. In addition, the MTAs were capable of binding DNA molecules for transfection. The MTA/pDNA complex showed relatively good transfection efficiency in hMSCs (compared to the commercial transfection agent, Lipofectamine) and good biocompatibility. MTA-treated hMSCs were successfully visualized after transplantation via MR and optical imaging system over 14 days. These studies highlight the challenges associated with the potential advantages of designing multi-modal nanostructured materials as tools for genetic materials delivery and cell-tracking in stem cell therapy.

Differentiation of endothelial progenitor cells into endothelial cells by heparin-modified supramolecular pluronic nanogels encapsulating bFGF and complexed with VEGF165 genes.

Specific genes and growth factors are involved in stem cell differentiation. In this study, we fabricated a delivery carrier for both protein and gene delivery that was introduced into human endothelial progenitor cells (EPCs). The highly negative charge carried by the heparin-modified pluronic nanogels allowed for binding to growth factors and localization in the core of nanogels. The residues of negatively charged heparin can complex with positively charged cationic materials, making it suitable for gene delivery. Supramolecular nanogels can be easily encapsulated the hydrophilic drugs and highly positive surfaces can be complexed with negative charge carrying plasmid DNA (pDNA). The size distribution, gel retardation, and denaturation of encapsulated growth factors and supramolecular nanogels modified with heparin were evaluated. The supramolecular nanogels containing basic fibroblast growth factors and complexing VEGF165 pDNA internalized into EPCs have been well formed vascular formation in matrigel gels. Proteins and genes introduced into EPCs using nanogels promoted neovascularization in an animal model of limb ischemia. EPCs that differentiated into endothelial cells both in vitro and in vivo were tested.

Aggrecan- and COMP-loaded poly-(lactic-co-glycolic acid) nanoparticles stimulate chondrogenic differentiation of human mesenchymal stem cells.

During embryogenesis, specific proteins expressed in cells have key roles in the formation of differentiated cells and tissues. Delivery of specific proteins into specific cells, both in vitro and in vivo, has proved to be exceedingly difficult. In this study, we developed a safe and efficient protein delivery system using encapsulation of proteins into biodegradable poly-(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). The PLGA NPs were used to deliver proteins into human mesenchymal stem cells (hMSCs). Fluorescent markers loaded into the PLGA NPs were used to verify the internalization of NPs into hMSCs using FACS analysis and confocal microscopy. With these methods, we demonstrated that the encapsulated model proteins are readily delivered into hMSCs, released from the NP vehicles, and, finally, moved into the cytosols. Using chondrogenesis-related proteins such as aggrecan and cartilage oligomeric matrix protein (COMP), chondrogenic differentiation of hMSCs treated with aggrecan and COMP encapsulated PLGA NPs was clearly observed and caused to differentiate into chondrocytes.

Poly(N-isopropylacrylamide-co-acrylic acid) nanogels for tracing and delivering genes to human mesenchymal stem cells.

Drugs, proteins, and cells can be macro- and micro-encapsulated by unique materials that respond to specific stimuli. The phases and hydrophobic interactions of these materials are reversibly altered by environmental stimuli such as pH and temperature. These changes can lead to self-assembly of the materials, which enables controlled drug release and safe gene delivery into cells and tissues. The fate of stem cells delivered by such methods is of great interest. The formation of transgenic tissues requires genes to be delivered safely into stem cells. A cell tracing vehicle and a gene delivery carrier were simultaneously introduced into human mesenchymal stem cells (hMSCs). A thermo-sensitive hydrogel, poly(N-isopropylacrylamide-co-acrylic acid) (p(NiPAAm-co-AAc)), was created to generate self-assembled nanoparticles with nanogel characteristics. Hydrophobic interactions mediated the binding of the carboxyl group on the outside of p(NiPAAm-co-AAc) with the amine group of iron oxide. Nanogels carrying iron oxide and a fluorescent dye were complexed with specific genes. These nanogels could be internalized by hMSCs, and the transplantation of these cells into mice was monitored by in vivo imaging. Self-assembled p(NiPAAm-co-dAAc) nanogels complexed with green fluorescent protein were highly expressed in hMSCs and are a potential material for gene delivery.

Multilineage differentiation of human-derived dermal fibroblasts transfected with genes coated on PLGA nanoparticles plus growth factors.

Wounded tissues and cells may be treated with growth factors and specific genes for the purpose of tissue repair and regeneration. To deliver specific genes into tissues and cells, this study presents the use of fabricated poly (DL-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) complexed with the cationic polymer poly (ethleneimine) (PEI). Through complexation with PEI, several types of genes (SOX9, Cbfa1, and C/EBP-α) were coated into PLGA NPs, which enhanced gene uptake into normal human-derived dermal fibroblast cells (NFDHCs) in vitro and in vivo. Several cell types (293T, HeLa, and fibroblast cells) were transfected with fluorescence-tagged PEI/SOX9, PEI/Cbfa1, and PEI/C/EBP-α gene-complexed PLGA NPs. The gene and protein expression levels in the cells were evaluated by RT-PCR, real-time quantitative PCR, Western blotting, and confocal laser microscopy. Fibroblast cells encapsulated in fibrin gels were transfected with the gene-complexed NPs plus specific growth factors (TGF-ß3, BMP-2, or IGF/bFGF), which induced chondrogenesis, osteogenesis, or adipogenesis both in vitro and after transplantation into nude mouse.

The use of anti-COX2 siRNA coated onto PLGA nanoparticles loading dexamethasone in the treatment of rheumatoid arthritis.

In drug delivery systems, some genes have the potential to interrupt unnecessary gene expression in specific target cells. In this study, two types of drug, glucocorticoids and siRNA, were co-delivered into conditioned cells to inhibit the expression of unnecessary genes and proteins involved in arthritis. To deliver the two factors into a human chondrocyte cell line (C28/I2), dexamethasone was first loaded into PLGA nanoparticles, and then drug-loaded PLGA nanoparticles were complexed with poly(ethyleneimine) (PEI)/siRNA. To test the co-delivery of siRNA and dexamethasone into chondrocytes, cells were transfected with green fluorescence protein siRNA (GFP siRNA) and drugs. After transfection with GFP siRNA, 70% reduction of C28/I2 cells demonstrated GFP expression, whereas MOCK carrying PLGA nanoparticles and PLGA nanoparticles without siRNA showed no differences of GFP expressions. COX-2 and iNOS productions in C28/I2 cells were examined after TNF-α pre-treatment to induce expression of arthritis-related molecules in vitro. The reduction of gene and protein expression associated with arthritis by transfection with dexamethasone-loaded and COX-2 siRNA-complexed PLGA nanoparticles was evaluated by RT-PCR, real time-qPCR, immunoblotting, immunohistochemistry, and immunofluorescence imaging.

Transfection of VEGF(165) genes into endothelial progenitor cells and in vivo imaging using quantum dots in an ischemia hind limb model.

Endothelial progenitor cells (EPCs) were transfected with fluorescently labeled quantum dot nanoparticles (QD NPs) with or without VEGF(165) plasmid DNA (pDNA) to probe the EPCs after in vivo transplantation and to test whether they presented as differentiated endothelial cells (ECs). Bare QD NPs and QD NPs coated with PEI or PEI + VEGF(165) genes were characterized by dynamic light scattering, scanning electron microscopy, and atomic force microscopy. Transfection of EPCs with VEGF(165) led to the expression of specific genes and proteins for mature ECs. A hind limb ischemia model was generated in nude mice, and VEGF(165) gene-transfected EPCs were transplanted intramuscularly into the ischemic limbs. At 28 days after transplantation, the VEGF(165) gene-transfected EPCs significantly increased the number of differentiated ECs compared with the injection of medium or bare EPCs without VEGF(165) genes. Laser Doppler imaging revealed that blood perfusion levels were increased significantly by VEGF(165) gene-transfected EPCs compared to EPCs without VEGF(165). Moreover, the transplantation of VEGF(165) gene-transfected EPCs increased the specific gene and protein expression levels of mature EC markers and angiogenic factors in the animal model.

SOX9 gene plus heparinized TGF-ß 3 coated dexamethasone loaded PLGA microspheres for inducement of chondrogenesis of hMSCs.

Microparticulated types of scaffolds have been widely applied in stem cell therapy and the tissue engineering field for the regeneration of wound tissues. During application of simple genes or growth factors and cell delivery vehicles, we designed a method that employs dexamethsone loaded PLGA microspheres consisting of polyplexed SOX9 genes plus heparinized TGF-ß 3 on the surface of polymeric microspheres prepared using a layer-by-layer (LbL) method. The fabrication of the polyplexed SOX9 genes plus heparinized TGF-ß 3 and their subsequent coating onto dexamethsone loaded PLGA microspheres represents a method for functionalization of the polymeric matrix. The use of SOX9 gene plus heparinized TGF-ß 3 coated dexamethsone loaded PLGA microspheres was evaluated to determine their potential as both gene carriers and cell delivery vehicle. By adhesion of hMSCs onto SOX9 gene plus heparinized TGF-ß 3 coated dexamethsone loaded PLGA microspheres, the chondrogenesis-related specific genes of collagen type II were increased 30 times comparing to control. Also, the specific extracellular matrix of glycosaminoglycan (GAG) production of hMSCs adhered onto SOX9 gene plus heparinized TGF-ß 3 coated dexamethasone loaded PLGA microspheres increased more 2.5 times than control group. Not only in vitro culture but in vivo results, the specific genes of COMP, aggrecan, collagen type II, and SOX9 showed much more gene expressions such as 20, 15, 10, 8 times.

Exogenous Nurr1 gene expression in electrically-stimulated human MSCs and the induction of neurogenesis.

In this study, synergistic effects of electrical stimulation and exogenous Nurr1 gene expression were examined to induce the differentiation of human mesenchymal stem cells (hMSCs) into nerve cells in in vitro culture system. A two-step procedure was designed to evaluate the effects of electrical stimulus and exogenous gene delivery for inducing neurogenesis. First, an electrical stimulation device was designed using gold nanoparticles adsorbed to the surface of a cover glass. Gold nanoparticles, as an electrical conductor for stem cells, are well-defined particles adsorbed to a polyethyleneimine (PEI)-coated cover glass. The nanoparticle morphology was examined by scanning electron microscope (SEM). Second, a plasmid carrying Nurr1 cDNA was complexed with biodegradable poly-(DL)-lactic-co-glycolic acid (PLGA) nanoparticles to support neurogenesis. To evaluate the neuronal differentiation of stem cells mediated by the treatment with either electrical stimulation and exogenous Nurr1 gene delivery, or both, the expression of neuron-specific genes and proteins was examined by RT-PCR and Western blotting. Cells transfected with exogenous Nurr1 genes plus electrical stimulation (250 mV for 1000 s) showed the greatest level of neurite outgrowth with a mean neurite length of 150 µm. Neurite length in cells treated with only one stimulus was not significant, approximately 10-20 µm. These results indicate that electrical stimulation and exogenous Nurr1 gene expression together may be adequate to induce nerve regeneration using stem cells.

Co-delivery of SOX9 genes and anti-Cbfa-1 siRNA coated onto PLGA nanoparticles for chondrogenesis of human MSCs.

Some genes expressed in stem cells interrupt and/or enhance differentiation. Therefore, the aim of this study was to inhibit the expression of unnecessary genes and enhance the expression of specific genes involved in stem cell differentiation by using small interfering RNA (siRNA) and plasmid DNA (pDNA) incorporated into cationic polymers as co-delivery factors. To achieve co-delivery of siRNA and pDNA to human mesenchymal stem cells (hMSCs), two different genes were complexed with poly(ethyleneimine) (PEI) and then coated onto poly(lactide-co-glycolic acid) (PLGA) nanoparticles (NP). To evaluate co-delivery of siRNA and pDNA into hMSCs, cells were transfected with green fluorescence protein (GFP) pDNA (GFP pDNA) and GFP siRNA (GFP siRNA). The percentage of GFP-expressing hMSCs decreased from 25.35 to 3.7% after transfection with GFP-DNA/PLGA NP (NPs) or GFP siRNA/PLGA NPs, whereas GFP-DNA/PLGA NPs and scramble siRNA (MOCK)/PLGA NPs had no effect on GFP expression. hMSCs cotransfected with coSOX9-pDNA/NPs and Cbfa-1-siRNA/NPs were tested both in vitro and in vivo using gel retardation, dynamic light scattering (DLS), and scanning electron microscope (SEM). The expression of genes and proteins associated with chondrogenesis was evaluated by FACS, RT-PCR, real time-qPCR, Western blotting, immunohistochemistry, and immunofluorescence imaging.

Chondrogenic potential of stem cells derived from amniotic fluid, adipose tissue, or bone marrow encapsulated in fibrin gels containing TGF-ß3.

In this study, several types of hMSCs, derived from bone marrow, adipose tissue, or amniotic fluid, were encapsulated in a fibrin hydrogel mixed with TGF-ß3 and then evaluated for their capacity for differentiation in vitro and in vivo. For determination of stem cell differentiation, RT-PCR, real time quantitative PCR (qPCR), histology, and immunohistochemical assays were used for analysis of chondrogenesis. Using these analysis methods, several of the cultured hMSCS were found to highly express genes and proteins specific to cartilage forming tissues. Additionally, similar trends in expression were found in tissue recovered from nude mice transplanted with several types of hMSCs encapsulated in a fibrin hydrogel containing TGF-ß3. The results of both in vitro and in vivo analyses showed that cultured or transplanted hMSCs mixed with TGF-ß3 in a fibrin hydrogel differentiated into chondrocytes, suggesting that these cells would be suitable for reconstruction of hyaline articular cartilage.

Chondrogenesis of mesenchymal stem cells and dedifferentiated chondrocytes by transfection with SOX Trio genes.

In this study, bone marrow-derived mesenchymal stem cells (MSCs), adipose-derived mesenchymal stem cells (ASCs) and dedifferentiated chondrocytes were transfected with SOX5, 6, and 9 genes (SOX Trio) and grown under pellet culture conditions (encapsulated in a fibrin hydrogel) to evaluate the chondrogenic potential in vitro and in vivo. RT-PCR, real-time quantitative PCR (qPCR), histology, and immunohistochemical assays were performed to determine the chondrogenic potential of the stem cells and dedifferentiated chondrocytes. Chondrogenic genes and proteins were more highly expressed in SOX Trio-expressing cells than in untransfected cells. In addition, not only specific genes and proteins, but cartilage-forming tissues were observed in nude mice transplanted with fibrin hydrogel encapsulated SOX Trio-expressing MSCs, ASCs, and dedifferentiated chondrocytes. Both in vitro and in vivo analyses revealed that fibrin hydrogel encapsulated cultured or transplanted cells transfected with the SOX Trio successfully differentiated into mature chondrocytes and could be used for the reconstruction of hyaline articular cartilage.