Active Cell Proliferation Research Articles

Sub-cytotoxic concentrations of ionic silver promote the proliferation of human keratinocytes by inducing the production of reactive oxygen species.

Silver-containing preparations are widely used in the management of skin wounds, but the effects of silver ions on skin wound healing remain poorly understood. This study investigated the effects of silver ions (Ag+) on the proliferation of human skin keratinocytes (HaCaT) and the production of intracellular reactive oxygen species (ROS). After treating HaCaT cells with Ag+ and/or the active oxygen scavenger N-acetyl cysteine (NAC), cell proliferation and intracellular ROS generation were assessed using CCK-8 reagent and DCFH-DA fluorescent probe, respectively. In addition, 5-bromo-2-deoxyUridine (BrdU) incorporation assays, cell cycle flow cytometry, and proliferating cell nuclear antigen (PCNA) immunocytochemistry were conducted to further evaluate the effects of sub-cytotoxic Ag+ concentrations on HaCaT cells. The proliferation of HaCaT cells was promoted in the presence of 10-6 and 10-5 mol/L Ag+ at 24, 48, and 72 h. Intracellular ROS generation also significantly increased for 5-60 min after exposure to Ag+. The number of BrdU-positive cells and the presence of PCNA in HaCaT cells increased 48 h after the addition of 10-6 and 10-5 mol/L Ag+, with 10-5 mol/L Ag+ markedly increasing the cell proliferation index. These effects of sub-cytotoxic Ag+ concentrations were repressed by 5 mmol/L NAC. Our results suggest that sub-cytotoxic Ag+ concentrations promote the proliferation of human keratinocytes and might be associated with a moderate increase in intracellular ROS levels. This study provides important experimental evidence for developing novel silver-based wound agents or dressings with few or no cytotoxicity.

Polymer–lipid hybrid nanoparticles-based paclitaxel and etoposide combinations for the synergistic anticancer efficacy in osteosarcoma

In this study, paclitaxel and etoposide-loaded lipid–polymer hybrid nanoparticles (PE-LPN) was successful prepared and evaluated for physicochemical and anticancer effect. Nanosized PE-LPN was obtained with a perfect spherical morphology. PE-LPN exhibited a controlled release of two drugs in a sequential manner. The nanoparticles exhibited a typical endocytosis-mediated cellular uptake in cancer cells. The ratiometric combination of paclitaxel (PTX) and etoposide (ETP) were significantly more cytotoxic than individual drugs. Importantly, superior cytotoxic effect was observed for dual-drug-loaded PE-LPN than cocktail combination at a much lower dose. Similarly, PE-LPN exhibited a significantly higher apoptosis of cancer cells (∼45%) compared to that of any other groups with higher caspase-3 and -8 activity. Importantly, PE-LPN showed a remarkable tumor regression effect and exhibited a 2-fold superior efficacy than free drugs. PE-LPN treated group showed significantly less Ki-67 positive cells (less than 25%) than PTX/ETP and single drug treated groups, suggesting less active cell proliferation and a considerably higher tumor growth inhibition effect. The results collectively showed that combination of drugs could greatly improve the therapeutic property of chemotherapeutic drugs. By combining ETP with PTX (a powerful anticancer drug) in a polymer–lipid hybrid nanoparticle system, therapeutic efficacy could be improved in osteosarcoma treatments.

Leukocyte telomere length in mild cognitive impairment and Alzheimer's disease patients

Numerous studies have reported an association between shortened leukocyte telomere length (LTL) and increased risk of Alzheimer's disease (AD). In this study we investigated the relationship between LTL and AD development, including in the analysis patients with amnestic mild cognitive impairment (aMCI), a clinical entity considered prodromal of AD. LTL (T/S ratio) was measured in patients with AD (n=61) or aMCI (n=46), and compared with LTL of age-matched controls (n=56). Significant LTL differences were observed between controls, aMCI and AD patients (p<0.0001), with mean LTL values (±s.d) in the order: AD patients (0.70±0.15)<aMCI patients (0.80±0.14)<controls (0.88±0.15). A positive relationship (linear regression p=0.004) was observed between LTL and cognitive performance (measured by Mini Mental State Examination score). LTL did not differ by APOE genotype. The shortened LTL observed in AD patients appears to stem from progressive telomere erosion possibly correlated with the cognitive decline characterizing conversion from aMCI to AD. LTL reduction, indicating active cell proliferation, may reflect immune system involvement in AD pathogenesis.

Root-Knot and Cyst Nematodes Activate Procambium-Associated Genes in Arabidopsis Roots.

Developmental plasticity is one of the most striking features of plant morphogenesis, as plants are able to vary their shapes in response to environmental cues. Biotic or abiotic stimuli often promote organogenesis events in plants not observed under normal growth conditions. Root-knot nematodes (RKNs) are known to parasitize multiple species of rooting plants and to induce characteristic tissue expansion called galls or root-knots on the roots of their hosts by perturbing the plant cellular machinery. Galls contain giant cells (GCs) and neighboring cells, and the GCs are a source of nutrients for the parasitizing nematode. Highly active cell proliferation was observed in galls. However, the underlying mechanisms that regulate the symptoms triggered by the plant-nematode interaction have not yet been elucidated. In this study, we deciphered the molecular mechanism of gall formation with an in vitro infection assay system using RKN Meloidogyne incognita, and the model plant Arabidopsis thaliana. By taking advantages of this system, we performed next-generation sequencing-based transcriptome profiling, and found that the expression of procambium identity-associated genes were enriched during gall formation. Clustering analyses with artificial xylogenic systems, together with the results of expression analyses of the candidate genes, showed a significant correlation between the induction of gall cells and procambium-associated cells. Furthermore, the promoters of several procambial marker genes such as ATHB8, TDR and WOX4 were activated not only in M. incognita-induced galls, but similarly in M. javanica induced-galls and Heterodera schachtii-induced syncytia. Our findings suggest that phytoparasitic nematodes modulate the host’s developmental regulation of the vascular stem cells during gall formation.

Abstract 1949: Salvage pathway enzyme HPRT as a molecular marker for Burkitt’s Lymphoma

Abstract The aim of this study is to investigate the potential of Hypoxanthine phosphoribosyltransferase (HPRT) as a surface biomarker and target for future immunotherapies in Burkitt’s B-cell Lymphoma. B-cell malignancies are the most common type of childhood cancer. Development of immunotherapies could improve current treatment. HPRT is a cytosolic transferase involved in nucleotide production via the purine salvage pathway. Altered expression of TK1, a salvage pathway enzyme, is an indicator of prognosis and diagnosis in multiple cancer types due to active proliferation of cells and the resulting elevated nucleotide demand. It has previously been reported that some salvage pathway enzymes are found on the surface of Burkitt’s Lymphoma cells. HPRT presence on the surface of this B-cell lymphoma subtype could provide a target for adoptive cell transfer and other immunotherapies. The potential surface presentation of HPRT was assessed using flow cytometry, scanning electron microscopy (SEM), and cytoplasmic staining on both healthy lymphocytes and Burkitt’s Lymphoma cells (Raji). Flow cytometry experiments with HPRT antibodies and fluorescent-labeled secondary antibodies show that Raji cells exhibit an 81.4% (p-value .0001) positive fluorescence shift when compared to IgG controls (1.5%). Healthy lymphocytes had a fluorescence shift of 2.38% (p-value .9787). The presence of HPRT on the surface of both Raji cells and healthy lymphocytes was further confirmed using gold-labeled antibodies. Utilizing a scanning electron microscope, the presence of the protein on the surface was evaluated and quantified via increases in gold weight percentage of the sample. When treated with antibodies against HPRT, there was a significant increase in gold binding along with an increase in gold weight percentage. These results suggest a direct relationship between HPRT and the surface of Burkitt’s lymphoma cells, indicating HPRT as a potential target for future immunotherapeutic treatment in Burkitt’s B-cell lymphoma pediatric patients. Citation Format: Michelle H. Townsend, John Ellis Lattin, Michael D. Anderson, Abigail Felsted, Edwin Velazquez, Evita Weagel, Richard Robison, Kim L. O'Neill. Salvage pathway enzyme HPRT as a molecular marker for Burkitt’s Lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1949. doi:10.1158/1538-7445.AM2017-1949

Efficacy of gamma-irradiated adipose-derived stem cells for treatment of thin endometrium in rats

Transplantation of adipose-derived stem cells (ADSCs) is associated with potential risks of late complications including tumorigenesis due to the active proliferation of the cells. We aimed to test the effect of transplantation of ADSCs with suppressed proliferation by gamma irradiation in the treatment of thin endometrium in rats. ADSCs were isolated from female SD rats and identified by detecting the surface antigens with flow cytometry. After exposure to gamma irradiation at 0, 5 Gy and 10 Gy, the cells were examined for changes in colony-forming ability. Twenty-four female rats with chemically induced thin endometrium were randomized into 4 equal groups and at 6-8 h after modeling, the rats received intrauterine injection of non-irradiated ADSCs (group I), 5 Gy irradiated ADSCs (group II), 10 Gy irradiated ADSCs (group III), or PBS only (group IV). Endometrial pathology was analyzed with HE staining in these rats in the third estrus phase following the cell transplantation. The ADSCs showed a complete loss of proliferative capacity after exposure to 10 Gy irradiation. After the cell transplantation, the endometrium thickness was thicker in group I and II than in group IV (P<0.01), but there was no significant difference between groups III and IV. Gamma irradiation impairs the proliferative capacity of ADSCs in vitro. Exposure to 10 Gy irradiation causes a total loss of proliferation capacity of the ADSCs, which have no therapeutic potential; 5 Gy irradiation causes partial loss of proliferation capacity of the cells, which still retain the activity to promote endometrial cell regeneration.

Spatial concordance of tumor proliferation and accelerated repopulation from pathologic images to 18F-FLT PET images.

e23100 Background: PET imaging with 18F-fluorothymidine (18F-FLT) can potentially be used to identify tumor subvolumes for selecting dose escalation in radiation therapy. The aim of this study was to monitor tumor cell proliferation and repopulation during fractionated radiotherapy and investigated the spatial concordance of tumor cell proliferation and repopulation with 18F-FLT tracer uptake. Methods: Mice bearing A549 xenograft tumors were assigned to 5 different irradiated groups (3f/6d, 6f/12d, 9f/18d, 12f/24d and 18f/36d) with 2 Gy/fractions and non-irradiated group. Serial 18F-FLT micro PET scans were performed at different time points, the maximum of standard uptake value (SUVmax) were measured to detect the feasible time of tumor repopulation during irradiation. Ex vivo images of the spatial pattern of intratumor 18F-FLT uptake and Ki-67 labeling index (LI) were obtained from thin tumor tissue sections. A layer-by-layer comparison between SUVmax and Ki-67 LI results, including the thresholds at which maximum overlap occurred between FLT-segmented areas and areas of active cell proliferation, were conducted to evaluate the spatial imaging pathology correlation. Results: The SUVmax were observed decreases in the 3f/6d group (P = 0.000), compared to these for non-irradiated tumors. However, it was significantly increased in the 6f/12d later, and then gradually reduced with treatment time prolonged again after 6f/12d group. Proliferation changes on pathology imaging at 6f/12d were also confirmed. Significant correlations were found between the SUVmax and Ki-67 LI of all ROIs in each in vitro tumor of cell proliferation group (Ps &lt; 0.001). Similar results were also found in each tumor of accelerated repopulation group (Ps &lt; 0.001). Furthermore, both of the mean ORRs were more than 50% in all layer of the tumor cell proliferation and accelerated groups. Regions of high-intensity 18F-FLT uptake in the autoradiographs exhibited prominent staining for Ki-67. Conclusions: 18F-FLT PET may be a promising imaging surrogate of tumor proliferative response to fractionated radiotherapy and might help make adaptive radiation oncology treatment plan.

BMP4 inhibits PDGF-induced proliferation and collagen synthesis via PKA-mediated inhibition of calpain-2 in pulmonary artery smooth muscle cells.

In the present study, we investigated the effect of bone morphogenetic protein 4 (BMP4) on PDGF-induced cell proliferation and collagen synthesis in pulmonary artery smooth muscle cells (PASMCs). Normal human PASMCs were incubated with and without PDGF-BB in the absence and presence of BMP4 for 0.5 to 24 h. The protein levels of collagen-I, p-Smad2/3, p-Smad1/5, and intracellular active TGF-β1, calpain activity, and cell proliferation were then measured. The results showed that BMP4 induced an increase in p-Smad1/5 but had no effect on the protein levels of collagen-I, p-Smad2/3, and intracellular active TGF-β1 and calpain activity in control PASMCs. Nevertheless, BMP4 attenuated increases in cell proliferation and protein levels of collagen-I, p-Smad2/3, and intracellular active TGF-β1 and calpain activity in PASMCs exposed to PDGF-BB. Moreover, BMP4 increased PKA activity and inhibition of PKA prevented the inhibitory effects of BMP4 on PDGF-BB-induced calpain activation in normal PASMCs. The PKA activator forskolin recapitulated the suppressive effect of BMP4 on PDGF-induced calpain activation. Furthermore, BMP4 prevented a PDGF-induced decrease in calpain-2 phosphorylation at serine-369 in normal PASMCs. Finally, BMP4 did not attenuate PDGF-induced increases in cell proliferation, collagen-I protein levels, and calpain activation and did not induce PKA activation and did not prevent a PDGF-induced decrease in calpain-2 phosphorylation at serine-369 in PASMCs from idiopathic pulmonary arterial hypertension (PAH) patients. These data demonstrate that BMP4 inhibits PDGF-induced cell proliferation and collagen synthesis via PKA-mediated inhibition of calpain-2 in normal PASMCs. The inhibitory effects of BMP4 on PDGF-induced cell proliferation, collagen synthesis, and calpain-2 activation are impaired in PASMCs from PAH patients, which may contribute to pulmonary vascular remodeling in PAH.

Optimization of culture medium for scarless healing of fetal mouse wounds and analysis of regions with active cell proliferation

Objective To optimize the culture medium for scarless wound healing in outbred fetal Kunming (KM) mice, and to locate and preliminarily analyze the region with active cell proliferation. Methods After 6 pregnant mice were sacrificed at the gestational age of 15 days, a total of 180 skin grafts were obtained from the back of 60 fetal mice, and wounds on the skin grafts were made uniformly with minimally invasive sterile device. Then, these skin grafts with wounds were randomly and equally divided into 6 groups to be treated with high-glucose Dulbecco′s modified Eagle′s medium (DMEM) , DMEM+ 5% fetal bovine serum (FBS) , DMEM+ 10% FBS, low-glucose Eagle′s minimum essential medium (MEM) , MEM+ 5% FBS, and MEM+ 10% FBS for 3 days, respectively. Then, these skin grafts were embedded in optimal cutting temperature (OCT) compound, and subjected to hematoxylin and eosin (HE) staining to select the optimal culture condition for wound healing. Under the optimal culture condition, the region with active cell proliferation was located by labeling and tracking cutaneous stem cells with 5-ethynyl-2-deoxyuridine (EdU) , and activator protein-1 (AP-1) expression was detected by immunofluorescent staining. Results After 3-day cultivation, wound healing rates significantly differed among the DMEM group, DMEM+ 5% FBS group, DMEM+ 10% FBS group, MEM group, MEM+ 5% FBS group and MEM+ 10% FBS group (0, 3.33%, 6.67%, 3.33%, 46.67% and 26.67%, respectively, χ2= 41.39, P < 0.05) . Additionally, the MEM+ 5% FBS group showed a significantly higher wound healing rate than the other groups except the MEM+ 10% FBS group (all P < 0.01) . Logistic regression analysis showed that the type of basal medium (MEM: OR= 11.717, 95% CI: 3.274-41.934, P < 0.001) and FBS concentrations (5% FBS: OR= 24.625, 95% CI: 3.027-200.299, P= 0.003; 10% FBS: OR= 13.449, 95% CI: 1.618-111.813, P= 0.016) were factors influencing fetal wound healing. Under the culture condition of 5% FBS+ MEM, the dermis and epidermis healed well without epidermal thickening. The cutaneous stem cell labeling technique showed that the papillary dermis and basal layer of the epidermis were the two major regions with active cell proliferation in the wound of fetal mouse skin. Moreover, AP-1 was expressed abundantly in these two regions as well. Conclusions The culture condition of 5% FBS+ MEM is considered to be optimal for in vitro wound healing in fetal mice. The papillary dermis and basal layer of the epidermis are two major regions with active cell proliferation during wound healing in fetal mouse skin, and play important roles in wound healing process. Key words: Wound healing; Cicatrix; Transcription factor AP-1; Scarless wound healing; Fetal mice

Young Bone-Marrow Sca-1+ Stem Cells Rejuvenate the Aged Heart and Improve Function after Injury through PDGFR\u03b2-Akt pathway

Bone marrow (BM) reconstitution with young BM cells in aged recipients restores the functionality of cardiac resident BM-derived progenitors. This study investigated the cell type primarily responsible for this effect. We reconstituted old mice with BM cells from young or old mice and found that the number of stem cell antigen 1 (Sca-1) cells homing to the heart was significantly greater in young than old chimeras. We then reconstituted old mice with young BM Sca-1+ or Sca-1− cells. We found that Sca-1 cells repopulated the recipient BM and homed to the heart. The number of BM-derived cells in the aged myocardium co-expressing PDGFRβ was 3 times greater in Sca-1+ than Sca-1− chimeric mice. Sca-1+ chimeras had more active cell proliferation in the infarcted heart and improved ventricular function after MI. The improved regeneration involved activation of the PDGFRβ/Akt/p27Kip1 pathway. Sca-1+ stem cells rejuvenated cardiac tissue in aged mice. Restoration of the Sca-1+ subset of stem cells by BM reconstitution improved cardiac tissue regeneration after injury in aged mice.

In vitro Antiproliferative and Apoptosis Inducing Effect of Allium atroviolaceum Bulb Extract on Breast, Cervical, and Liver Cancer Cells.

Natural products are considered potent sources for novel drug discovery and development. The multiple therapeutic effects of natural compounds in traditional medicine motivate us to evaluate the cytotoxic activity of bulb of Allium atroviolaceum in MCF7 and MDA-MB-231, HeLa and HepG2 cell lines. The bulb methanol extract of A. atroviolaceum was found to be an active cell proliferation inhibitor at the time and dose dependent manner. Determination of DNA content by flow cytometry demonstrated S and G2/M phase arrest of MCF-7 cell, correlated to Cdk1 downregulation, S phase arrest in MDA-MB-231 which is p53 and Cdk1-dependent, sub-G0 cell cycle arrest in HeLa aligned with Cdk1 downregulation, G0/G1, S, G2/M phase arrest in HepG2 which is p53-dependent. Apoptosis as the mechanism of cell death was confirmed by morphology study, caspases activity assay, as well as apoptosis related gene expression, Bcl-2. Caspase-8, -9, and -3 activity with downregulation of Bcl-2 illustrated occurrence of both intrinsic and extrinsic pathways in MCF7, while caspase-3 and -8 activity revealed extrinsic pathway of apoptosis, although Bcl-2 downregulated. In HeLa cells, the activity of caspase-9 and -3 and downregulation of Bcl-2 shows intrinsic pathway or mitochondrial pathway, whereas HepG2 shows caspase independent apoptosis. Further, the combination of the extract with tamoxifen against MCF7 and MDA-MB-231 and combination with doxorubicin against HeLa and HeG2 demonstrated synergistic effect in most concentrations, suggests that the bulb of A. atroviolaceum may be useful for the treatment of cancer lonely or in combination with other drugs.

Cell-to-cell heterogeneity of EWSR1-FLI1 activity determines proliferation/migration choices in Ewing sarcoma cells

Ewing sarcoma is characterized by the expression of the chimeric EWSR1-FLI1 transcription factor. Proteomic analyses indicate that the decrease of EWSR1-FLI1 expression leads to major changes in effectors of the dynamics of the actin cytoskeleton and the adhesion processes with a shift from cell-to-cell to cell-matrix adhesion. These changes are associated with a dramatic increase of in vivo cell migration and invasion potential. Importantly, EWSR1-FLI1 expression, evaluated by single-cell RT-ddPCR/immunofluorescence analyses, and activity, assessed by expression of EWSR1-FLI1 downstream targets, are heterogeneous in cell lines and in tumours and can fluctuate along time in a fully reversible process between EWSR1-FLI1high states, characterized by highly active cell proliferation, and EWSR1-FLI1low states where cells have a strong propensity to migrate, invade and metastasize. This new model of phenotypic plasticity proposes that the dynamic fluctuation of the expression level of a dominant oncogene is an intrinsic characteristic of its oncogenic potential.

頭頸部神経内分泌小細胞癌8症例の治療経験

Small cell neuroendocrine carcinoma of the head and neck is a rarely occurring poorly differentiated and high-grade malignant neoplasm characterized by highly active proliferation of neuroendocrine tumor cells. There are no established therapies for this disease. To clarify the clinical course and develop effective treatment(s) for the carcinoma, we reviewed the data of 8 patients of small cell neuroendocrine carcinoma of the head and neck treated by us between 2006 and 2014 at the Department of Otolaryngology, Gifu University School of Medicine and our affiliated hospitals. The patients consisted of 3 men and 5 women, ranging in age from 38 to 84 years old (mean : 60.9 years). The tumor arose from the nasal cavity or the paranasal sinuses in 3 cases, from the parotid grand in 2 cases, from the oropharynx in 2 cases, and from the hypopharynx in 1 case. The tumor that arose from the hypopharynx was a combined small-cell carcinoma with squamous cell carcinomas, and the one that arose from the oropharynx had already metastasized to the brain. Most of the patients were treated by chemotherapy and radiotherapy based on the treatment employed for small cell carcinoma of the lung. Only the patient in whom the tumor arose from a paranasal sinus was treated by surgery despite the definitive diagnosis of small cell carcinoma. We selected CPT-11 and a platinum agent for 4 patients, and VP-16 and a platinum agent for 3 patients as the first-line chemotherapy. Although two patients showed carcinoma-free survival, one died of recurrence of the regional lymph node metastases and five died of distant metastases despite the absence of locoregional recurrence. The 5-year survival rate was a dismal 25%, suggesting that we need to establish effective treatment(s) for the control of distant metastases in cases of the small cell neuroendocrine carcinoma of the head and neck.

Effect of Gelatin on Osteogenic Cell Sheet Formation Using Canine Adipose-Derived Mesenchymal Stem Cells

Osteogenically differentiated cell sheet techniques using mesenchymal stem cells (MSCs) are available to stimulate bone regeneration. The advantage of the cell sheet technique is delivering live cells effectively into the focal region. We developed a novel osteogenic cell sheet technique by adding gelatin to osteogenic cell medium. Gelatin-induced osteogenic cell sheets (GCSs) were compared to conventional osteogenic cell sheets (OCSs). Undifferentiated MSCs (UCs) were used as a control. The morphology of these cell sheets was evaluated microscopically and histologically. The time-dependent cell proliferation rate was estimated by DNA quantification. The expression of osteogenic gene markers and the number of calcium depositions were assessed by quantitative real-time polymerase chain reaction and Alizarin red S (ARS) staining, respectively. GCSs were thicker and stronger than OCSs. GCSs showed a significantly higher cell proliferation rate compared to OCSs (p < 0.05). GCSs exhibited significantly higher upregulation of BMP-7 mRNA compared to OCSs (p < 0.05). Both GCSs and OCSs showed negative ARS reactivity on day 10, but only GCSs showed positive ARS reactivity on day 21. With this technique, we observed active cell proliferation with abundant ECM and upregulation of osteogenic bone markers, and our results suggest that GCSs could be promising for therapeutic applications in bone regeneration.

Monitoring the Response of Hyperbilirubinemia in the Mouse Brain by In Vivo Bioluminescence Imaging.

Increased levels of unconjugated bilirubin are neurotoxic, but the mechanism leading to neurological damage has not been completely elucidated. Innovative strategies of investigation are needed to more precisely define this pathological process. By longitudinal in vivo bioluminescence imaging, we noninvasively visualized the brain response to hyperbilirubinemia in the MITO-Luc mouse, in which light emission is restricted to the regions of active cell proliferation. We assessed that acute hyperbilirubinemia promotes bioluminescence in the brain region, indicating an increment in the cell proliferation rate. Immunohistochemical detection in brain sections of cells positive for both luciferase and the microglial marker allograft inflammatory factor 1 suggests proliferation of microglial cells. In addition, we demonstrated that brain induction of bioluminescence was altered by pharmacological displacement of bilirubin from its albumin binding sites and by modulation of the blood–brain barrier permeability, all pivotal factors in the development of bilirubin-induced neurologic dysfunction. We also determined that treatment with minocycline, an antibiotic with anti-inflammatory and neuroprotective properties, or administration of bevacizumab, an anti-vascular endothelial growth factor antibody, blunts bilirubin-induced bioluminescence. Overall the study supports the use of the MITO-Luc mouse as a valuable tool for the rapid response monitoring of drugs aiming at preventing acute bilirubin-induced neurological dysfunction.

Evaluation of a new mouse model for studying dental pulpal responses to GaAlAs laser irradiation

ObjectivesThe molecular mechanisms regulating pulpal responses to GaAlAs laser irradiation remain to be clarified. This study aimed to assess the feasibility of a mouse model for studying pulpal responses to GaAlAs laser irradiation. MethodsMaxillary first molars of 5-week-old ICR mice were irradiated at an output power of 1.0W for 180s, and samples were collected at intervals of 0, 1, 3, 5, 7, 10, and 14 days. The demineralized paraffin sections were processed for hematoxylin and eosin staining, immunohistochemistry for nestin (a marker for odontoblast differentiation) and Ki67 (a marker for cell proliferation), and a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. ResultsThe intense nestin immunoreactivity in the odontoblast layer of the mesial pulp was weakened immediately after irradiation and was almost lost on Days 1–3, although the extent of pulpal damage was variable among individual animals. At around Day 1, numerous TUNEL-positive cells appeared in the degenerative zone and gradually decreased in number by Day 14. Active cell proliferation occurred in the mesial pulp during Days 5–10. Nestin-positive odontoblast-like cells appeared along the pulp-dentin border by Day 10, resulting in tertiary dentin formation on Day 14. ConclusionsThe current output energy induced apoptosis in the affected dental pulp, followed by active cell proliferation, resulting in tertiary dentin formation. This is the first report regarding laser irradiation of teeth in an in vivo mouse model. This model could enable further understanding of the function of certain proteins, including transcriptional factors.

Abstract 3863: Cancer immunotherapy: Could TK1 be used as a target for colon cancer

Abstract The aim of this study is to determine whether Thymidine Kinase 1 (TK1) would be a suitable target for future immunotherapeutic treatment of colon cancer. The salvage pathway enzyme TK1 has been shown to be upregulated in cancer patients due to active proliferation of cancer cells and the resulting high demand for nucleotides. Present in both the cytosol and the serum of cancer patients, TK1 levels can be used to not only predict cancer occurrence, but also to predict tumor aggressiveness and future remission. While serum levels of TK1 have been established, surface expression of the enzyme have not been fully characterized. In colon cancer cells, TK1 has been shown to strongly associate with the plasma membrane. In this project we explored the presence of TK1 on the surface of colon cancer cells (HT29 and SW620 cell lines) using flow cytometry, confocal microscopy, scanning electron microscopy, membrane separation, and cytoplasmic staining. Using fluorescent antibodies conjugated to FITC, expression levels as high as 19% are observed in HT29's and 12% in SW620's in comparison to sodium potassium ATPase surface levels of 11% and 6% respectively. Confocal microscopy images revealed direct overlap between cells stained with a rhodamine red membrane dye and with a FITC conjugated anti-TK1 antibody which indicates a direct relationship between TK1 and the cellular surface of cancer cells. To further confirm surface expression, TK1 levels were assessed using gold labeling and scanning electron microscopy. Gold levels indicate the physical location of the TK1 on the surface of the colon cancer cells and their relative abundance. TK1 surface levels in colon cancer cells corresponded with the surface expression levels of sodium potassium ATPase and share relatively the same abundance. These results strongly indicate a direct relationship between TK1 and the surface of colon cancer cells, and suggests TK1 as a potential target for future immunotherapeutic treatment. Citation Format: Michelle H. Townsend, Evita G. Weagel, Wei Meng, Craig Chandler, Richard A. Robison, Kim L. O’Neill. Cancer immunotherapy: Could TK1 be used as a target for colon cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3863.

Prominent Lymphatic Vessel Hyperplasia with Progressive Dysfunction and Distinct Immune Cell Infiltration in Lymphedema

Lymphedema is a common complication that occurs after breast cancer treatment in up to 30% of the patients undergoing surgical lymph node excision. It is associated with tissue swelling, fibrosis, increased risk of infection, and impaired wound healing. Despite the pronounced clinical manifestations of the disease, little is known about the morphological and functional characteristics of the lymphatic vasculature during the course of lymphedema progression. We used an experimental murine tail lymphedema model where sustained fluid stasis was generated on disruption of lymphatic flow, resulting in chronic edema formation with fibrosis and adipose tissue deposition. Morphological analysis of the lymphatic vessels revealed a dramatic expansion during the course of the disease, with active proliferation of lymphatic endothelial cells at the early stages of lymphedema. The lymphatic capillaries exhibited progressively impaired tracer filling and retrograde flow near the surgery site, whereas the collecting lymphatic vessels showed a gradually decreasing contraction amplitude with unchanged contraction frequency, leading to lymphatic contraction arrest at the later stages of the disease. Lymphedema onset was associated with pronounced infiltration by immune cells, predominantly Ly6G(+) and CD4(+) cells, which have been linked to impaired lymphatic vessel function.

MicroRNA-126 Targeting PIK3R2 Inhibits NSCLC A549 Cell Proliferation, Migration, and Invasion by Regulation of PTEN/PI3K/AKT Pathway

BackgroundOur study explored whether the microRNA-126 (miR-126)-mediated PTEN/PI3K/AKT (phosphatase and tensin homology deleted on chromosome 10/phosphatidylinositol 3-kinase regulatory subunit-β/AKT) signaling pathway by targeting PIK3R2 affects the proliferation, migration, and invasion of non–small-cell lung cancer (NSCLC) A549 cells. Materials and MethodsQuantitative real-time polymerase chain reaction was used to measure the expression of miR-126 in A549 cells. The MTT (methyl thiazolyl tetrazolium) assay, cell scratch test, Transwell assay, and Western blot were used to detect the proliferation, migration, and invasion of A549 cells and protein expression in A549 cells, respectively. ResultsThe expression of miR-126 decreased and the expression of PIK3R2 increased in A549 cells (P < .05, for both). Upregulation of miR-126 resulted in the decrease of the proliferation, migration, and invasive abilities of A549 cells, the downregulation of the expression of PIK3R2, PI3K, and phosphorylated Akt (p-Akt) protein, and the upregulation of PTEN expression (P < .05 for all). Also, these abilities of A549 cells increased, and the expression of these 3 proteins was upregulated with downregulation of miR-126 (P < .05 for all). The results of the dual luciferase reporter gene assay showed that PIK3R2 was the target gene of miR-126. PIK3R2, PI3K, and p-Akt proteins were downregulated, but PTEN protein was upregulated as PIK3R2 was silenced or the inhibitor of the PTEN/PI3K/AKT signaling pathway increased. Also, downregulation of miR-126 with silencing of PIK3R2 or increasing the inhibitor of the pathway caused increased PI3K and p-Akt protein expression and increased active proliferation, migration, and invasive abilities of A549 cells (P < .05 for all). ConclusionThe upregulation of miR-126 in NSCLC A549 cells can reduce the expression of the target gene PIK3R2 and influence the PTEN/PI3K/AKT signaling pathway, suppressing the proliferation, migration, and invasive abilities of A549 cells.

Cellular Ontogeny and Hierarchy Influence the Reprogramming Efficiency of Human B Cells into Induced Pluripotent Stem Cells.

Although B cells have been shown to be refractory to reprogramming into pluripotency, induced pluripotent stem cells (iPSCs) have been very recently generated, at very low efficiency, from human cord blood (CB)- and peripheral blood (PB)-derived CD19+CD20 + B cells using nonintegrative tetracistronic OSKM-expressing Sendai Virus (SeV). Here, we addressed whether cell ontogeny and hierarchy influence the reprogramming efficiency of the B-cell compartment. We demonstrate that human fetal liver (FL)-derived CD19 + B cells are 110-fold easier to reprogram into iPSCs than those from CB/PB. Similarly, FL-derived CD34+CD19 + B progenitors are reprogrammed much easier than mature B cells (0.46% vs. 0.11%). All FL B-cell iPSCs carry complete VDJH rearrangements while 55% and 45% of the FL B-progenitor iPSCs carry incomplete and complete VDJH rearrangements, respectively, reflecting the reprogramming of developmentally different B progenitors (pro-B vs. pre-B) within a continuous differentiation process. Finally, our data suggest that successful B-cell reprogramming relies on active cell proliferation, and it is MYC-dependent as identical nonintegrative polycistronic SeV lacking MYC (OSKL or OSKLN) fail to reprogram B cells. The ability to efficiently reprogram human fetal primary B cells and B precursors offers an unprecedented opportunity for studying developmental B-lymphopoiesis and modeling B-cell malignances.