Targeting nicotinamide N-methyltransferase decreased aggressiveness of osteosarcoma cells

BACKGROUND

Osteosarcoma (OS) is a primary bone malignancy that mostly affects young people, characterized by high metastatic potential, and a marked chemoresistance that is responsible for disease relapse in most patients. Therefore, it is necessary to identify novel molecules to setup targeted strategies to improve the clinical outcome. The enzyme nicotinamide N-methyltransferase (NNMT) catalyses the N-methylation of nicotinamide and other analogs, playing a crucial role in the biotransformation of drugs and xenobiotics. NNMT overexpression was reported in a wide variety of cancers, and several studies demonstrated that is able to promote cell proliferation, migration and resistance to chemotherapy. The aim of this study was to explore the potential involvement of NNMT in OS.

METHODS

Immunohistochemical analyses have been performed to evaluate NNMT expression in selected OS and healthy bone tissue samples. Subsequently, OS cell lines have been transfected with vectors targeting NNMT mRNA (shRNAs) and the impact of this downregulation on migration, cell proliferation, and response to chemotherapeutic treatment was also analysed by wound healing, MTT, SRB and Trypan blue assays, respectively.

RESULTS

Results showed that OS samples display a significantly higher NNMT expression compared with healthy tissue. Preliminary results suggest that NNMT silencing in OS cell lines is associated to a decrease of cell proliferation and migration, as well as to enhanced sensitivity to chemotherapy. Data obtained showed that NNMT may represent an interesting marker for OS detection and a promising target for effective anti-cancer therapy.

Betacyanins enhance vitexin-2-O-xyloside mediated inhibition of proliferation of T24 bladder cancer cells

Betacyanins (BC) were purified from beetroot (Beta vulgaris var. rubra L.) and tested, alone or in combination with vitexin-2-O-xyloside (XVX) from Beta vulgaris var. cicla L., for their ability to reduce the proliferation rate in T24 bladder cancer cells. Combination of BC and XVX exhibited a synergistic effect concerning the inhibition of proliferation in T24 cancer cells at 24 and 48 h but not after 72 h of incubation. The induction of apoptosis was evidenced by means of fluorescence activated cell sorting (FACS) analysis, as well as through the increase in caspase 3 and 8 activities. Using RTqPCR experiments, it was shown that the combination of XVX + BC was able to enhance the expression levels of pro-apoptotic BAX and downregulate anti-apoptotic BIRC5 (survivin), as well as pro-survival CTNNB1 (β-catenin). The most evident effect of BC was the increase of the activity of caspase 8, leading to induction of extrinsic apoptosis. Moreover, XVX, BC and their combination showed no cytotoxic effect on normal human skin NCTC 2544 keratinocytes. These results demonstrated the efficacy and the mechanisms of the action of BC and XVX, extracted from edible plants, and suggested that a diet or a nutrition supplement, enriched with these bioactive molecules, could be used in the prevention of human bladder cancer.

Use of supercharged cover screw as static magnetic field generator for bone healing, 2nd part: in vivo enhancement of bone regeneration in rabbits

In 1979, Pulsed electromagnetic fields (PEMFs) were approved by the Food and Drug Administration as an effective method in the treatment of non-unions. As well as PEMFs, also static magnetic fields (SMFs) have been widely investigated in orthopaedic studies. Even if the exact mechanism of action is not well understood, a large number of studies showed specific effects both at cellular and tissue levels. As bone fracture healing and osseointegration share the same biological events, the application of magnetic field stimulation in order to facilitate the osseointegration process has been suggested. In this study we investigated BIC and newly formed bone volume around dental implants inserted in the tibia of New Zealand rabbits after SMF stimulation, generated by a small-customized cover-screw-shaped neodymium-iron-bore magnet placed in the inner cavity of dental implants. As a result, we found that the SMF field generated around dental implants enhanced bone healing in the animal model. Our findings represent, to our knowledge, the first ready clinical technique for dental implants showing the ability of SMF to promote the osteogenesis process in vivo.

Molecular analysis of endometrial inflammation in preterm birth

Spontaneous preterm birth (sPTB) represents the 35%-45% of all preterm birth (PTB) cases and its etiology is unknown. We investigated if the expression level of endometrial cytokines and angiogenetic factors is related to the onset of sPTB.Endometrial tissues from non-pregnant women who experienced sPTB and from non-pregnant women who did not experience sPTB were collected and examined for their expression profile. With this aim, the PCR Array analysis was performed and data were confirmed by Real-Time PCR. Differential gene expression measurements (pathological vs control tissues) showed a significant up-regulation for genes codifying for two angiogenetic factors known as connective tissue growth factor (CTGF), and coagulation factor III (F3). An increased level of expression was detected both for tyrosine kinase endothelial (TEK) and for transforming growth factor beta 2 (TGF-β2) genes but without reaching the statistical significance. The expression level of interleukin 10 receptor alpha (IL10RA) gene was slightly decreased in pathological group compared to control one but, as well as forTEK and TGF-β2 measurements, without reaching the statistical significance. Our work is the first to correlate the imbalance in endometrial district of non -pregnant women with sPTB. These data could suggest a new point of view whence to read sPTB. We need additional clinical and biological studies to clarify sPTB pathogenesis.

Use of supercharged cover screw as static magnetic field generator for bone healing, 1st part: in vitro enhancement of osteoblast-like cell differentiation

Since 1979, Pulsed electromagnetic fields (PEMFs) have been approved by the Food and Drug Administration as an effective method in the treatment of non-unions. As well as PEMFs, also static magnetic fields (SMFs) have been widely investigated in orthopaedic studies. Even if the exact mechanism of action is not well understood, a large number of studies showed specific effects both at cellular and tissue levels. As bone fracture healing and osseointegration share the same biological events, the application of magnetic field stimulation in order to facilitate the osseointegration process has been suggested. In this study we investigated the proliferation rate and gene expression profile of MG63 osteoblastic-like cells after a 24, 48 and 72-hour SMF stimulation, generated by a small, customized cover screw-shaped neodymium-iron-bore magnet placed in the inner cavity of a dental implant. As a result, we found that the application of a SMF to osteoblastic-like cells does slightly decrease cell proliferation rate while enhancing the expression of those genes correlated to differentiation and mineralization. Our findings represent, to our knowledge, the first clinical ready technique for dental implants showing the ability of SMF to promote the osteogenesis process in vitro.

Genetic Analysis of Oral Squamous Cell Carcinoma by cDNA Microarrays Focused Apoptotic Pathway

We investigated mRNA expression of the genes involved in the apoptotic mechanism in oral squamous cell carcinoma (OSCC) by cDNA microarray. The aim of this study was to identify genes mainly involved in tumorigenesis, comparing the difference of gene expression in neoplastic and non-neoplastic tissues. Eight frozen samples of OSCC and the corresponding normal oral mucosa were treated to obtain mRNA. The mRNA extracted from these specimens was converted into cDNA and analyzed with “SuperArray GEArray Q Series Human Apoptosis Gene Array kit”. Our results showed that in OSCC there is a different expression of CRADD, FADD, ATM and APAF-1 genes compared to normal mucosa. Real-Time PCR, and Western blot analysis were performed on a separate cohort of patients in order to confirm the results obtained by DNA microarray. Our analysis of apoptotic process through microarray technology confirmed that different molecules could be responsible or favour the imbalance of apoptosis in cancer tissues. Microarray technology has made it possible to analyze the expression of multiple genes in a single experiment. However, most commercial array kits, designed to include as many genes as possible, produce a vast amount of data that often is difficult to interpret. In addition, the cost of equipment is often prohibitive. In contrast, the focused kit used was a complete, affordable and effective method to improve knowledge of molecular specific pathways.

Platelet amyloid precursor protein isoform expression in Alzheimer's disease: evidence for peripheral marker

Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by a progressive cognitive and memory decline. Among peripheral markers of AD, great interest has been focused on the amyloid precursor protein (APP). In this regard, platelets represent an important peripheral source of APP since it has been demonstrated that the three major isoforms, that are constituted of 770, 751 and 695 aa residues, are inserted in the membrane of resting platelets. APP 751 and APP 770 contain a Kunitz-type serine protease inhibitor domain (APP KPI) and APP 695 lacks this domain. To address this issue, we first examined the platelet APP isoform mRNAs prospectively as biomarker for the diagnosis of AD by means of real-time quantitative PCR, and then evaluated the correlation between APP mRNA expression levels and cognitive impairment of enrolled subjects. Differential gene expression measurements in the AD patient group (n=18) revealed a significant up-regulation of APP TOT (1.52-fold), APP KPI (1.32-fold), APP 770 (1.33-fold) and APP 751 (1.26-fold) compared to controls (n=22). Moreover, a statistically significant positive correlation was found between APP mRNA levels (TOT, KPI, 770 and 751) and cognitive impairment. Since AD definitive diagnosis still relies on pathological evaluation at autopsy, the present results are consistent with the hypothesis that platelet APP could be considered a potential reliable peripheral marker for studying AD and could contribute to define a signature for the presence of AD pathology.

Neurogenic potential of mesenchymal-like stem cells from human amniotic fluid: the influence of extracellular growth factors

Amniotic fluids contain human stem cells, among which mesenchymal stem cells could be isolated. These cells have multipotent differentiation ability and no tumorigenic potential after transplantation in mice. These features make them good candidates for in vitro studies and for therapeutic purposes. The aim of this study was to isolate mesenchymal stem cell-like cultures from different amniotic fluids in order to study in vitro their neurogenic potential and assess if this process could be reproducible and standardized. We focused attention on the possible differential effects of soluble growth factors. Immunophenotypical and molecular characterization showed that the 31 amniotic fluid-derived cultures expressed mesenchymal markers as well as some stemness properties. These cells also appeared to be responsive to purines or acetylcholine showing an intracellular calcium increase, also reported for mesenchymal stem cells derived from other sources. Interestingly, in the presence of retinoic acid, these cells assumed a neuronal-like morphology. In addition, functional and molecular analyses revealed that retinoic acid-treated cells showed immature electric functional properties, the expression of neuronal markers and stemness genes. In conclusion, even if further investigations are required, the results presented here contribute to support the finding that amniotic fluid contains cells able to differentiate in vitro towards neural-like lineage in the presence of retinoic acid. The ability of retinoic acid to induce a possible neuronal progenitor culture makes the model useful to study a possible in vivo transplantation of these cells and to contribute to define the protocols for cell therapy.

Placental overexpression of transforming growth factor-beta3 in the HELLP syndrome

OBJECTIVE

To evaluate the placental expression of transforming growth factor-beta3 (TGF-beta3) in patients with HELLP syndrome and pre-eclampsia compared to controls, and its correlation to Doppler velocimetry analysis of the utero-placental blood flow.

STUDY DESIGN

Real-time PCR analysis was performed, after cesarean section, in placental samples from 10 women affected by HELLP syndrome, 10 women with pre-eclampsia and 10 controls. Pulsatility indices on Doppler waveform analysis from uterine and umbilical arteries were measured.

RESULTS

The mean TGF-beta3 expression was significantly higher in patients with HELLP syndrome compared with the control group (p < 0.001), and no difference was observed in the pre-eclampsia group. TGF-beta3 expression correlated positively with umbilical PI (p < 0.001).

CONCLUSIONS

TGF-beta3 may play a key role as regulator of a variety of cellular events occurring during HELLP syndrome, high local expression of this growth factor may be responsible for remodeling of the placental structure, which results in the dysfunction of maternal-fetal circulation.

Roles of tumor necrosis factor alpha (TNF-alpha) and the p55 TNF receptor in CD1d induction and coxsackievirus B3-induced myocarditis

Giving C57BL/6 mice 10(4) PFU of coxsackievirus B3 (H3 variant) fails to induce myocarditis, but increasing the initial virus inoculum to 10(5) or 10(6) PFU causes significant cardiac disease. Virus titers in the heart were equivalent at days 3 and 7 in mice given all three virus doses, but day 3 titers in the pancreases of mice inoculated with 10(4) PFU were reduced. Tumor necrosis factor alpha (TNF-alpha) concentrations in the heart were increased in all infected mice, but cytokine levels were highest in mice given the larger virus inocula. TNF-alpha(-/-) and p55 TNF receptor-negative (TNFR(-/-)) mice developed minimal myocarditis compared to B6;129 or C57BL/6 control mice. p75 TNFR(-/-) mice were as disease susceptible as C57BL/6 animals. No significant differences in virus titers in heart or pancreas were observed between the groups, but C57BL/6 and p75 TNFR(-/-) animals showed 10-fold more inflammatory cells in the heart than p55 TNFR(-/-) mice, and the cell population was comprised of high concentrations of CD4(+) gamma interferon-positive and Vgamma4(+) cells. Cardiac endothelial cells isolated from C57BL/6 and p75 TNFR(-/-) mice upregulate CD1d, the molecule recognized by Vgamma4(+) cells, but infection of TNF(-/-) or p55 TNFR(-/-) endothelial cells failed to upregulate CD1d. Infection of C57BL/6 endothelial cells with a nonmyocarditic coxsackievirus B3 variant, H310A1, which is a poor inducer of TNF-alpha, failed to elicit CD1d expression, but TNF-alpha treatment of H310A1-infected endothelial cells increased CD1d levels to those seen in H3-infected cells. TNF-alpha treatment of uninfected endothelial cells had only a modest effect on CD1d expression, suggesting that optimal CD1d upregulation requires both infection and TNF-alpha signaling.

Myocarditis susceptibility in female mice depends upon ovarian cycle phase at infection

Female BALB/c mice were infected with coxsackievirus B3 in the diestrus, proestrus, estrus, or metestrus phases of the ovarian cycle. Cycle stage was determined by vaginal smear. All mice were killed 7 days after infection. Females infected in the diestrus and especially the proestrus phases developed myocarditis. CD4+ T cells expressing interferon-gamma (IFNgamma) infiltrate the myocardium in these two phases, whereas CD4+ T cells expressing IL-4 are more frequent during estrus. Cardiac virus titers were determined 15 h and 7 days after infection. No differences in virus titer were seen at 7 days. These studies show that natural hormone variations can have substantial effects on viral pathogenicity presumably due to hormone effects on the immune system.

Vgamma4(+) T cells promote autoimmune CD8(+) cytolytic T-lymphocyte activation in coxsackievirus B3-induced myocarditis in mice: role for CD4(+) Th1 cells

T cells expressing the Vgamma4 T-cell receptor (TCR) promote myocarditis in coxsackievirus B3 (CVB3)-infected BALB/c mice. CD1, a major histocompatibility complex (MHC) class I-like molecule, is required for activation of Vgamma4(+) cells. Once activated, Vgamma4(+) cells initiate myocarditis through gamma interferon (IFN-gamma)-mediated induction of CD4(+) T helper type 1 (Th1) cells in the infected animal. These CD4(+) Th1 cells are required for activation of an autoimmune CD8(+) alphabeta TCR(+) effector, which is the predominant pathogenic agent in this model of CVB3-induced myocarditis. Activated Vgamma4(+) cells can adoptively transfer myocarditis into BALB/c mice infected with a nonmyocarditic variant of CVB3 (H310A1) but cannot transfer myocarditis into either uninfected or CD1(-/-) recipients, demonstrating the need for both infection and CD1 expression for Vgamma4(+) cell function. In contrast, CD8(+) alphabeta TCR(+) cells transfer myocarditis into either infected CD1(-/-) or uninfected recipients, showing that once activated, the CD8(+) alphabeta TCR(+) effectors function independently of both virus and CD1. Vgamma4(+) cells given to mice lacking CD4(+) T cells minimally activate the CD8(+) alphabeta TCR(+) cells. These studies show that Vgamma4(+) cells determine CVB3 pathogenicity by their ability to influence both the CD4(+) and CD8(+) adaptive immune response. Vgamma4(+) cells enhance CD4(+) Th1 (IFN-gamma(+)) cell activation through IFN-gamma- and CD1-dependent mechanisms. CD4(+) Th1 cells promote activation of the autoimmune CD8(+) alphabeta TCR(+) effectors.