Metformin Protects Rat Skeletal Muscle from Physical Exercise-Induced Injury.

Metformin (Met) is a drug commonly prescribed in type 2 diabetes mellitus. Its efficacy is due to the suppression of hepatic gluconeogenesis, enhancement of peripheral glucose uptake and lower glucose absorption by the intestine. Recent studies have reported Met efficacy in other clinical applications, such as age-related diseases. Despite the wide clinical use of Met, its mechanism of action on muscle and its effect on muscle performance are unclear. We investigated the effects of Met combined with training on physical performance (PP) in healthy rats receiving Met for 8 weeks while undergoing daily moderate exercise. We evaluated the following: PP through graded endurance exercise test performed before the beginning of the training protocol and 48 h before the end of the training period; blood ALT, AST, LDH and CK-MB levels in order to address muscle damage; and several blood and muscle myokines and the expression of factors believed to be involved in muscle adaptation to exercise. Our data demonstrate that Met does not improve the positive effects of exercise on performance, although it protects myocytes from exercise-induced damage. Moreover, given that Met positively affects exercise-induced muscle adaptation, our data support the idea of the therapeutic application of Met when muscle function and structure are compromised.

Cystatin SN (CST1) as a Novel Salivary Biomarker of Periodontitis.

Identification of biomarkers could help in assessing periodontal health status and monitoring treatment outcomes. Therefore, the aim of this cross-sectional study was to identify potential innovative salivary biomarkers for the diagnosis of periodontitis using an untargeted proteomic approach. Forty-five healthy non-smoker participants diagnosed as having periodontally healthy conditions (H), severe periodontitis (P), and healthy but reduced periodontium after active periodontal treatment (T) were consecutively enrolled (15 per each group) in the study. A higher number of spots were identified in the proteome of unstimulated whole saliva collected from H and T subjects compared with P group, mainly within the range of 8-40 kDa. Protein spots of interest were analysed by MALDI-TOF-MS, allowing the identification of cystatin SN (CST1) isoform, as confirmed by Western blot. CST1 was markedly expressed in the H group, while it was absent in most P samples (p < 0.001). Interestingly, a distinct CST1 expression was observed in saliva from T patients. CST1 was negatively correlated with the percentage of pathological sites (p < 0.001) and was effective in discriminating active periodontitis from healthy periodontal status (whether H or T). Therefore, salivary CST1 may be a promising non-invasive biomarker for periodontal disease diagnosis and monitoring.

Influence of locally delivered doxycycline on the clinical and molecular inflammatory status of intrabony defects prior to periodontal regeneration: A double-blind randomized controlled trial.

OBJECTIVES: To test the effect of locally delivered doxycycline (DOX) administered 2 weeks prior to minimally invasive periodontal regeneration in terms of presurgical inflammatory status and cytokine expression profile in the gingival crevicular fluid (GCF). Secondary aim was to assess the early wound healing index (EHI) at 2 weeks after surgery. BACKGROUND: It is hypothesized that healing after periodontal regeneration is dependent on preoperative soft tissue condition, and that local antibiotics may improve the site-specific inflammatory status at short time. METHODS: Sites associated with periodontal intrabony defects requiring regenerative surgery and showing bleeding on probing (BoP) were included. At T0, experimental sites were randomly treated with subgingival instrumentation with or without topic DOX application. After 2 weeks (T1), defects were approached by means of minimally invasive surgical technique. GCF was sampled at both T0 and T1 for inflammatory biomarker analysis. Two weeks after surgery, the EHI was evaluated (T2). RESULTS: Forty-four patients were included. At T1, the number of BoP+ sites was statistically significantly less in the test group (27.3% vs. 72.7%; p < .01). The total amount of interleukin (IL)-1ß (p < .001), matrix-metalloproteinases (MMP)-8 (p < .001), and MMP-9 (p = .010) in the GCF significantly decreased in the test group at T1, with relevant differences compared to controls. At T2, the EHI had an average value of 1.45 ± 0.86 in the test group while in the control, it was 2.31 ± 1.43 (p = .027). A statistically significantly positive correlation was observed between the amount of IL-1ß and MMP-9 and EHI scores. CONCLUSIONS: Within the limitations of this study, sites treated with DOX showed improved clinical and molecular inflammatory parameters before surgery, as well as soft tissue healing 2 weeks after surgery.

Reviving a Classic Antigen with a Cutting-Edge Approach: Nanobodies for HER2+ Breast Cancer.

The serendipitous discovery of nanobodies (NBs) around two decades ago opened the door to new possibilities for innovative strategies, particularly in cancer treatment. These antigen-binding fragments are derived from heavy-chain-only antibodies naturally found in the serum of camelids and sharks. NBs are an appealing agent for the progress of innovative therapeutic strategies because they combine the advantageous assets of smaller molecules and conventional monoclonal antibodies (mAbs). Moreover, the possibility to produce NBs using bacterial systems reduces manufacturing expenses and speeds up the production process, making them a feasible option for the development of new bio-drugs. Several NBs have been developed over the past 10 years and are currently being tested in clinical trials for various human targets. Here, we provide an overview of the notable structural and biochemical characteristics of NBs, particularly in their application against HER2, an extracellular receptor that often gets aberrantly activated during breast cancer tumorigenesis. The focus is on the recent advancements in diagnostic and therapeutic research up to the present date.

Comparing Ionic Profile of Gingival Crevicular Fluid and Saliva as Distinctive Signature of Severe Periodontitis.

Although increasing evidence is emerging on the contribution of chemical elements in periodontal health, no studies have concomitantly evaluated the ionic profile in gingival crevicular fluid (GCF) and saliva in relation to the underlying periodontal status. Our hypothesis is that these biofluids have distinctive ionic content. Therefore, the aim of this cross-sectional study was to analyze the elemental composition of GCF and saliva in order to explore which biological matrix and which combination of elements could discriminate between periodontitis and periodontal health. Twelve ions were analyzed in GCF and unstimulated saliva from 54 subjects (18 periodontally healthy, 18 untreated severe periodontitis and 18 treated severe periodontitis) using inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES). These analytical techniques were able to determine levels of sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg), while the other elements were below the detection threshold. Na and K ions were detected at elevated concentration in untreated periodontitis compared with treated periodontitis and healthy periodontium. Ca was increased in untreated periodontitis, but the difference was not significant. In saliva, only Na was significantly associated with periodontitis. The combination of Na and K in GCF enabled the correct assignment of a subject to the periodontitis or healthy group. Based on these preliminary results, GCF demonstrated higher clustering potential than saliva.

Chemical Oral Cancerogenesis Is Impaired in PI3Kγ Knockout and Kinase-Dead Mice.

We investigated the role of PI3Kγ in oral carcinogenesis by using a murine model of oral squamous carcinoma generated by exposure to 4-nitroquinoline 1-oxide (4NQO) and the continuous human cancer cell line HSC-2 and Cal-27. PI3Kγ knockout (not expressing PI3Kγ), PI3Kγ kinase-dead (carrying a mutation in the PI3Kγ gene causing loss of kinase activity) and wild-type (WT) C57Bl/6 mice were administered 4NQO via drinking water to induce oral carcinomas. At sacrifice, lesions were histologically examined and stained for prognostic tumoral markers (EGFR, Neu, cKit, Ki67) and inflammatory infiltrate (CD3, CD4, CD8, CD19 and CD68). Prevalence and incidence of preneoplastic and exophytic lesions were significantly and similarly delayed in both transgenic mice versus the control. The expression of prognostic markers, as well as CD19+ and CD68+ cells, was higher in WT, while T lymphocytes were more abundant in tongues isolated from transgenic mice. HSC-2 and Cal-27 cells were cultured in the presence of the specific PI3Kγ-inhibitor (IPI-549) which significantly impaired cell vitality in a dose-dependent manner, as shown by the MTT test. Here, we highlighted two different mechanisms, namely the modulation of the tumor-infiltrating cells and the direct inhibition of cancer-cell proliferation, which might impair oral cancerogenesis in the absence/inhibition of PI3Kγ.

An Innovative Strategy for Oral Biofilm Control in Early Childhood Based on a Resveratrol-Cyclodextrin Nanotechnology Approach.

The purpose of this randomized controlled study was to evaluate the clinical efficacy of a novel oral spray containing resveratrol (RV) in controlling bacterial biofilm and gingival inflammation in early childhood. RV, a natural polyphenol, known for its anti-inflammatory and anti-infective activities, was included in a nanovector of 2-hydroxypropyl-beta-cyclodextrins (HPßCD) to improve its bioavailability. A total of 64 children between two and five years of age with plaque-induced gingivitis were randomly included in two equal groups. Both groups were enrolled in a mechanical plaque control program for a period of four weeks, while the test group was also instructed to use the RV-HPßCD mouthwash (in spray formulation) once daily, after toothbrushing. All children underwent three oral hygiene motivation sessions, 14 days apart, during which the full-mouth presence of bacterial plaque, gingival inflammation, dental stain and salivary pH were recorded. At two-week appointment, they also received professional plaque removal. The use of RV-based oral spray significantly reduced the amount of dental plaque and the percentage of bleeding sites and improved salivary pH compared to the control group at both two- and four-week examinations. Based on these promising results, the local delivery of RV-HPßCD via oral spray could enhance the control of dental biofilm in early childhood, when antiseptic mouthwashes are not recommended.

Gingival Crevicular Fluid Cytokines in Moderate and Deep Sites of Stage III Periodontitis Patients in Different Rates of Clinical Progression.

Clinical criteria are inappropriate to measure the degree of susceptibility to progression of periodontal damage. Thus, the aim of this study was to assess whether gingival crevicular fluid (GCF) levels of cytokines could discriminate patients suffering from stage III periodontitis with moderate (Grade B) and rapid rates of progression (Grade C) prior to and 6 months after non-surgical periodontal treatment. GCF samples were obtained from moderate and deep sites of 20 patients diagnosed as Grade B and 20 patients as grade C stage III periodontitis and analyzed for interleukin (IL)-1ß, IL-9, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) using a high-sensitivity Bio-Plex Suspension Array System. At baseline, higher IL-1ß but lower IL-9 GCF levels were observed in moderate sites of the grade C compared to the grade B group. In spite of comparable clinical improvement, this difference maintained after treatment, suggesting a residual pro-inflammatory state. In deep sites, no differences were observed between periodontitis groups except for VEGF levels that decreased more in Grade B periodontitis at 6 months post-therapy. A mathematical model was constructed to identify Grade C periodontitis patients based on the subjects' GCF levels of IL-1ß and IL-9, which achieved an area under the receiver-operating characteristic (ROC) curve of 0.94. This study can contribute to the early assessment of risk of future breakdown in periodontitis patients.

ICP-Mass-Spectrometry Ionic Profile of Whole Saliva in Patients with Untreated and Treated Periodontitis.

Over the past decade, there has been growing interest in the association between macro and trace minerals in body fluids and systemic diseases related to chronic inflammation and oxidative stress. Due to the paucity of data in the literature on periodontitis, the aim of this cross-sectional study was to assess the relationship between mineral elements in saliva and periodontal status in patients with untreated and treated periodontitis compared to periodontally healthy controls. Salivary samples from 66 nonsmoker healthy patients (20 periodontally healthy, 24 untreated severe periodontitis and 22 treated severe periodontitis) were analyzed by using inductively coupled plasma mass-spectrometry (ICP-MS). Significant increases in copper (Cu), sodium (Na), iron (Fe) and manganese (Mn) concentrations occurred in saliva of severe periodontitis subjects compared to periodontally healthy controls. No differences were detected between healthy controls and treated periodontitis patients apart from levels of zinc (Zn) and lithium (Li) that were found to be increased and reduced, respectively, in periodontitis group. Most subjects were correctly separated by cluster analysis into active periodontitis and periodontally healthy individuals. Treated periodontitis individuals were classified as healthy subjects. Based on these preliminary results, the assessment of salivary concentration of mineral elements might be useful in discriminating periodontal health and disease.

Childhood acute poisoning in the Italian North-West area: a six-year retrospective study.

BACKGROUND: Data about acute poisoning in Italian pediatric patients are obsolete or absent. This study would partially fill this exiting gap and compare the scene with others around the world. METHODS: A retrospective evaluation was performed on a 2012-2017 data registry of the Children's Emergency Department at the Regina Margherita Hospital of Turin, where 1030 children under age 14 were accepted with a diagnosis of acute intoxication. RESULTS: The median age of the patients was 2.2 years (IQR 2.3) and 55% were male. Events occurred mostly in children aged 1-4 years (n = 751, 72.9%). Six hundred and eight patients (59%) were exposed to Nonpharmaceutical agents, the household cleaning products being the more frequent (n = 298, 49%). Exposure to Pharmaceuticals were 422 (41%); the most common Pharmaceuticals were analgesics (n = 88, 20.8%), psychotropics (n = 77, 18.2%) and cardiovascular (n = 53, 12.6%) drugs. The 85% of the intoxications occurred accidentally, the 10.6% as therapeutic error, the 2.3% as suicide attempts and the 1.5% for recreational purposes. No patient died. CONCLUSIONS: Despite acute poisoning being a relevant problem in pediatric emergency, our results would seem to paint a less worrying picture if compared to other countries, mainly when considering the children hospitalized in the pediatric intensive care unit and the number of deaths. Nevertheless, our study might represent a tool for public health authorities to program incisive interventions.

Patient-Specific iPSC-Derived Endothelial Cells Provide Long-Term Phenotypic Correction of Hemophilia A.

We generated patient-specific disease-free induced pluripotent stem cells (iPSCs) from peripheral blood CD34+ cells and differentiated them into functional endothelial cells (ECs) secreting factor VIII (FVIII) for gene and cell therapy approaches to cure hemophilia A (HA), an X-linked bleeding disorder caused by F8 mutations. iPSCs were transduced with a lentiviral vector carrying FVIII transgene driven by an endothelial-specific promoter (VEC) and differentiated into bona fide ECs using an optimized protocol. FVIII-expressing ECs were intraportally transplanted in monocrotaline-conditioned non-obese diabetic (NOD) severe combined immune-deficient (scid)-IL2rγ null HA mice generating a chimeric liver with functional human ECs. Transplanted cells engrafted and proliferated in the liver along sinusoids, in the long term showed stable therapeutic FVIII activity (6%). These results demonstrate that the hemophilic phenotype can be rescued by transplantation of ECs derived from HA FVIII-corrected iPSCs, confirming the feasibility of cell-reprogramming strategy in patient-derived cells as an approach for HA gene and cell therapy.

Yeast-Derived Recombinant Avenanthramides Inhibit Proliferation, Migration and Epithelial Mesenchymal Transition of Colon Cancer Cells.

Avenanthramides (Avns), polyphenols found exclusively in oats, are emerging as promising therapeutic candidates for the treatment of several human diseases, including colon cancer. By engineering a Saccharomyces cerevisiae strain, we previously produced two novel phenolic compounds, N-(E)-p-coumaroyl-3-hydroxyanthranilic acid (Yeast avenanthramide I, YAvnI) and N-(E)-caffeoyl-3-hydroxyanthranilic acid (Yeast avenanthramide II, YAvnII), which are endowed with a structural similarity to bioactive oat avenanthramides and stronger antioxidant properties. In this study, we evaluated the ability of these yeast-derived recombinant avenanthramides to inhibit major hallmarks of colon cancer cells, including sustained proliferation, migration and epithelial-mesenchymal transition (EMT). Using the human colon adenocarcinoma cell line HT29, we compared the impact of YAvns and natural Avns, including Avn-A and Avn-C, on colon cancer cells by performing MTT, clonogenic, adhesion, migration, and anchorage-independent growth assays, and analyzing the expression of EMT markers. We found that both YAvns and Avns were able to inhibit colon cancer cell growth by increasing the expression of p21, p27 and p53 proteins. However, YAvns resulted more effective than natural compounds in inhibiting cancer cell migration and reverting major molecular features of the EMT process, including the down-regulation of E-cadherin mRNA and protein levels.

Biomarker levels in gingival crevicular fluid of generalized aggressive periodontitis patients after non-surgical periodontal treatment.

OBJECTIVES: The aim of this study was to assess the effects of non-surgical periodontal treatment on gingival crevicular fluid (GCF) cytokines in patients with generalized aggressive periodontitis (GAgP), in relation to clinical parameters. MATERIALS AND METHODS: Data were obtained from 16 GAgP patients and 15 periodontally healthy controls. Periodontal parameters and GCF biomarker levels were evaluated at baseline and repeated 3 and 6 months after treatment for GAgP subjects. Moderate and deep pocket sites were analyzed separately. The amount of interleukin (IL)-1ß, IL-9, tumor necrosis factor (TNF)-α, platelet-derived growth factor (PDGF-bb), and vascular endothelial growth factor (VEGF) were measured using a highly specific and sensitive multiplex bead immunoassay. RESULTS: At baseline, cytokine levels in the moderate and deep pocket sites of GAgP patients were higher than those of the healthy control sites. In GAgP group, periodontal treatment led to improvement in all examined clinical parameters and resulted in a statistically significant reduction in the total amounts of IL-1ß, VEGF, and TNF-α, in comparison to baseline, already 3 months after therapy in both moderate and deep pocket sites and of PDGF-bb in deep sites (p < 0.01). At the concentration level, only IL-1ß and VEGF were affected. CONCLUSION: Non-surgical treatment of GAgP provided significant clinical benefits leading to a marked decrease in the GCF levels of some pro-inflammatory and pro-angiogenic cytokines, but not of IL-9 and PDGF-bb. CLINICAL RELEVANCE: Although the periodontal therapy successfully decreased clinical signs of inflammation, the GCF levels of some inflammatory cytokines were still elevated.

A Simple Protocol to Isolate, Characterize, and Expand Dental Pulp Stem Cells.

Adult stem cells reside in body tissues to preserve organs and whole organism homeostasis. They are acquiring a prominent role in the contemporary medicine. Many protocols to isolate and cultivate adult stem cells have been so far described, though they are often lengthy, laborious, and require very expansive instruments, materials, and reagents. On this basis, we describe a simple, cheap but at the same time functional method to: (1) isolate dental pulp stem cells (DPSC), (2) expand and cultivate DPSC, (3) cryopreserve DPSC, (4) characterize DPSC, and (5) differentiate DPSC into both mesenchymal and non-mesenchymal lineages.

Bioequivalence of Branded and Generic Oxaliplatin: From Preclinical Assessment to Clinical Incidence of Hypersensitivity Reactions.

BACKGROUND: Generic anticancer drugs represent an opportunity in terms of cost savings but there are some concerns about their tolerability. The safety profiles of generic versus branded oxaliplatin formulations have never been studied in detail. PATIENTS AND METHODS: We tested in vitro concentrations, stability and efficacy of branded versus generic oxaliplatin formulations, then we retrospectively collected data about hypersensitivity reactions (HSR) of 427 colorectal cancer patients treated with oxaliplatin-based regimens. RESULTS: No significant difference in oxaliplatin concentration or time-dependent antiproliferative activity between branded and generic oxaliplatin was detected. The incidence of HSR was 12.1% (33/273 patients) in those treated with branded and 9.8% (15/154 patients) in those treated with generic oxaliplatin (p=0.46). The occurrence of grade III-IV HSRs and severe HSRs leading to oxaliplatin discontinuation were comparable. CONCLUSION: No difference between generic and branded formulations of oxaliplatin were demonstrated in preclinical nor in clinical settings. Generic oxaliplatin can be considered a safe alternative to branded formulation.

Isolation and characterization of a spontaneously immortalized multipotent mesenchymal cell line derived from mouse subcutaneous adipose tissue.

The emerging field of tissue engineering and regenerative medicine is a multidisciplinary science that is based on the combination of a reliable source of stem cells, biomaterial scaffolds, and cytokine growth factors. Adult mesenchymal stem cells are considered important cells for applications in this field, and adipose tissue has revealed to be an excellent source of them. Indeed, adipose-derived stem cells (ASCs) can be easily isolated from the stromal vascular fraction (SVF) of adipose tissue. During the isolation and propagation of murine ASCs, we observed the appearance of a spontaneously immortalized cell clone, named m17.ASC. This clone has been propagated for more than 180 passages and stably expresses a variety of stemness markers, such as Sca-1, c-kit/CD117, CD44, CD106, islet-1, nestin, and nucleostemin. Furthermore, these cells can be induced to differentiate toward osteogenic, chondrogenic, adipogenic, and cardiogenic phenotypes. m17.ASC clone displays a normal karyotype and stable telomeres; it neither proliferates when plated in soft agar nor gives rise to tumors when injected subcutaneously in NOD/SCID-γ (null) mice. The analysis of gene expression highlighted transcriptional traits of SVF cells. m17.ASCs were genetically modified by lentiviral vectors carrying green fluorescent protein (GFP) as a marker transgene and efficiently engrafted in the liver, when injected in the spleen of NOD/SCID-γ (null) monocrotaline-treated mice. These results suggest that this non-tumorigenic spontaneously immortalized ASC line may represent a useful tool (cell model) for studying the differentiation mechanisms involved in tissue repair as well as a model for pharmacological/toxicological studies.

ErbB2 receptor over-expression improves post-traumatic peripheral nerve regeneration in adult mice.

In a transgenic mice (BALB-neuT) over-expressing ErbB2 receptor, we investigated the adult mouse median nerve in physiological and pathological conditions. Results showed that, in physiological conditions, the grip function controlled by the median nerve in BALB-neuT mice was similar to wild-type (BALB/c). Stereological assessment of ErbB2-overexpressing intact nerves revealed no difference in number and size of myelinated fibers compared to wild-type mice. By contrast, after a nerve crush injury, the motor recovery was significantly faster in BALB-neuT compared to BALB/c mice. Moreover, stereological assessment revealed a significant higher number of regenerated myelinated fibers with a thinner axon and fiber diameter and myelin thickness in BALB-neuT mice. At day-2 post-injury, the level of the mRNAs coding for all the ErbB receptors and for the transmembrane (type III) Neuregulin 1 (NRG1) isoforms significantly decreased in both BALB/c and BALB-neuT mice, as shown by quantitative real time PCR. On the other hand, the level of the mRNAs coding for soluble NRG1 isoforms (type I/II, alpha and beta) increased at the same post-traumatic time point though, intriguingly, this response was significantly higher in BALB-neuT mice with respect to BALB/c mice. Altogether, these results suggest that constitutive ErbB2 receptor over-expression does not influence the physiological development of peripheral nerves, while it improves nerve regeneration following traumatic injury, possibly through the up-regulation of soluble NRG1 isoforms.

Potentiation of amyloid-ß peptide neurotoxicity in human dental-pulp neuron-like cells by the membrane lipid peroxidation product 4-hydroxynonenal.

Lipid peroxidation is generally considered as primarily implicated in the pathogenesis of Alzheimer's disease (AD); one of its more reactive end products, 4-hydroxynonenal (HNE), has been shown to cause neuron dysfunction and degeneration. HNE production in the brain is stimulated by the amyloid-ß peptide (Aß), whose excessive accumulation in specific brain areas is a hallmark of AD. Conversely, Aß production is up-regulated by this multifunctional aldehyde. Findings reported here point to the ability of HNE and Aß to interact, with consequent potentiation of Aß's cytotoxicity as determined in vitro using neuron-like cells derived from human dental-pulp progenitor cells. Preincubation of cells with the aldehyde markedly up-regulated Aß uptake and intracellular accumulation, by overexpressing two of the three components of the plasma membrane multireceptor complex CD36/CD47/ß1-integrin: experimental and clinical data indicate that intraneuronal accumulation of Aß is an early event possibly playing a primary role in AD pathogenesis. That HNE-mediated overexpression of CD36 and ß1-integrin, which plays a key role in HNE's potentiating Aß neurotoxicity, in terms of necrosis, was confirmed when this effect was prevented by specific antibodies against the two receptors.

Self-renewal and multipotency coexist in a long-term cultured adult rat dental pulp stem cell line: an exception to the rule?

The stemness state is characterized by self-renewal and differentiation properties. However, stem cells are not able to preserve these characteristics in long-term culture because of the intrinsic fragility of their phenotype easily undergoing senescence or neoplastic transformation. Furthermore, although isolated from the same original tissue using similar protocols, adult stem cells can display dissimilar phenotypes and important cell clone/species contamination. Finally, the lack of a clear standardization contributes to complicate the comprehension about the stemness condition. In this context, cell lines displaying a particularly stable phenotype must be identified to define one or multiple benchmarks against which other stem cell lines could be reliably assessed. The present paper demonstrates that it is possible to isolate from the rat dental pulp a stem cell line (MUR-1) that does not display neoplastic transformation in long-term culture. MUR-1 cells stably express a broad range of stemness markers and are able to differentiate into adipogenic, osteogenic, chondrogenic, neurogenic, and cardiomyogenic lineages independently of the culture passages. Moreover, serial in vitro passages have not changed their immunophenotype, proliferation capacity, or differentiation potential. The uniqueness of these characteristics candidates MUR-1 as a model to reliably improve the understanding of the mechanisms governing the stem cell fate in the same as well as in other stem cell populations.

Differentiation-inducing factor-1 enhances 5-fluorouracil action on oral cancer cells inhibiting E2F1 and thymidylate synthase mRNAs accumulation.

PURPOSE: Differentiation-inducing factor-1 (DIF-1) is a morphogen originally identified in the amoebozoan Dictyostelium discoideum. In mammalian cells, it has been shown to activate GSK3ß, which in turn is expected to reduce levels of ß-catenin and cyclin D1, thus mediating DIF-1 antiproliferative properties. Since this could alter the expression and activity of E2F1 transcription factor and consequently those of the prognostic marker/chemotherapy target thymidylate synthase (TS), we evaluated (1) whether DIF-1 could effectively regulate these genes, (2) whether it could interfere with cell viability, and (3) whether DIF-1 activity could enhance the efficacy of the TS inhibitor 5-fluorouracil (5-FU). METHODS: We investigated the effects of DIF-1 in continuous human cell lines derived from two oral tumor histotypes (corresponding to an adenosquamous and a squamous carcinoma) and a gingival epithelium. We evaluated mRNA accumulation by means of quantitative real-time PCR and efficacy of drugs on cell viability by means of MTT assay. RESULTS: DIF-1 inhibited the accumulation of E2F1 mRNA and reduces TS mRNA levels in tumor cell lines, but did not alter mRNA levels in the gingival counterpart. As a result, it inhibited proliferation preferentially of tumor cell in time- and concentration-dependent manner. Moreover, it enhanced cytotoxic effects of 5-FU only in tumor cell, whereas reduced them in the gingival counterpart. CONCLUSIONS: These findings suggest a tumor-specific action of DIF-1 on oral carcinoma cells. Thus, interfering with E2F1 and TS transcription, DIF-1 potentiates TS enzymatic inhibitors.