Overexpression of nicotinamide N-methyltransferase in HSC-2 OSCC cell line: effect on apoptosis and cell proliferation.

OBJECTIVES: Oral squamous cell carcinoma (OSCC) is the most common malignancy of oral cavity. Despite advances in therapeutic approaches, the 5-year survival rate for oral cancer has not improved in the last three decades. Therefore, new molecular targets for early diagnosis and treatment of OSCC are needed. In the present study, we focused on the enzyme nicotinamide N-methyltransferase (NNMT). We have previously shown that enzyme expression is upregulated in OSCC and NNMT knockdown in PE/CA PJ-15 cells significantly decreased cell growth in vitro and tumorigenicity in vivo. MATERIAL AND METHODS: To further explore the role of the enzyme in oral cancer cell metabolism, HSC-2 cells were transfected with the NNMT expression vector (pcDNA3-NNMT) and the effect of enzyme upregulation on cell proliferation was evaluated by MTT assay. Subsequently, we investigated at molecular level the role of NNMT on apoptosis and cell proliferation, by exploring the expression of ß-catenin, survivin, and Ki-67 by real-time PCR. Moreover, we performed immunohistochemistry on 20 OSCC tissue samples to explore the expression level of NNMT and survivin ΔEx3 isoform. RESULTS: Enzyme upregulation significantly increased cell growth in vitro. Moreover, a positive correlation between NNMT and survivin ΔEx3 isoform expression levels was found both in HSC-2 cells and in OSCC tissue samples. CONCLUSION: Taken together, our results indicate a possible involvement of NNMT in the proliferation and tumorigenic capacity of OSCC cells and seem to suggest that the enzyme could represent a potential target for the treatment of oral cancer. CLINICAL RELEVANCE: The involvement of NNMT in cell growth and anti-apoptotic mechanisms seems to suggest that this enzyme could be a new therapeutic target to improve the survival of OSCC patients.

Involvement of transforming growth factor beta 1 in the transcriptional regulation of nicotinamide N-methyltransferase in clear cell renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common tumor of the kidney and its major histologic subtype is clear cell RCC (ccRCC). About 30% of diagnosed ccRCCs already have metastasis. Traditionally, localized ccRCC is treated with nephrectomy but the relapse rate is 30%. Thus, the discovery of effective biomarkers for early detection, as well as the identification of new targets for molecular-based therapy of ccRCC are urgently required. In this study, we focused on molecules that could modulate the trascription of the enzyme nicotinamide N-methyltransferase (NNMT) that is known to be up-regulated in ccRCC. Signal transducer and activator of transcription 3 (STAT3), interleukin 6 (IL-6), hepatocyte nuclear factor 1 beta (HNF-1ß) and transforming growth factor beta 1 (TGF-ß1) expression levels were determined in tumor and non tumor samples obtained from 30 patients with ccRCC, using Real-Time PCR. Results obtained showed that TGF-ß1 is significantly (p<0.05) overexpressed in tumor compared with normal tissue samples of ccRCC patients. Conversely, we did not find any statistically significant difference concerning STAT3, IL-6, HNF-1ß gene expression levels. TGF-ß1 up-regulation could be responsible for the high levels of NNMT observed in ccRCC. Targeting TGF-ß1 could improve the outcome of ccRCC patients due to its role in epithelial-mesenchymal transition (EMT), that is known to be associated with a worse overall survival (OS) in this neoplasm.

A Novel Benchtop Device for Efficient and Simple Purification of Cytokines, Growth Factors and Stem Cells from Adipose Tissue.

Lipoaspirates represent a source of adult stem cells, cytokines, and growth factors of adipocyte origin with immunomodulation and regenerative medicine potential. However, rapid and simple protocols for their purification using self-contained devices that can be deployed at the points of care are lacking. Here, we characterize and benchmark a straightforward mechanical dissociation procedure to collect mesenchymal stem cells (MSCs) and soluble fractions from lipoaspirates. IStemRewind, a benchtop self-contained cell purification device, allowed a one-procedure purification of cells and soluble material from lipoaspirates with minimal manipulation. The recovered cellular fraction contained CD73+, CD90+, CD105+, CD10+ and CD13+ MSCs. These markers were comparably expressed on MSCs isolated using IstemRewind or classic enzymatic dissociation procedures, apart from CD73+ MSCs, which were even more abundant in IStemRewind isolates. IstemRewind-purified MSCs retained viability and differentiation into adipocytes and osteocytes, even after a freezing-thawing cycle. Levels of IL4, IL10, bFGF and VEGF were higher compared to the pro-inflammatory cytokines TNFα, IL1ß and IL6 in the IStemRewind-isolated liquid fraction. In sum, IStemRewind can be useful for straightforward, rapid, and efficient isolation of MSCs and immunomodulatory soluble factors from lipoaspirates, opening the possibility to directly isolate and employ them at the point-of-care.

Predictors of cord blood unit cell content in a volume unrestricted large series collections: a chance for a fast and cheap multiparameter selection model.

BACKGROUND: Cord blood plays a very important role in stem cell transplantation and therapy with an emerging implication also in regenerative medicine. The number of cells available in a single cord blood unit (CBU), in particular, the CD34+ and total nucleated cell (TNC) content influences the transplantation clinical outcome. We analysed a very large series of CBUs, collected for private banking without any specific volume restriction, to deeply investigate the best predictors of cord blood stem cells content. METHODS: Maternal and neonatal clinic laboratory data of a total 2583 UCBs were obtained from the InScientiaFides cord blood bank based in Republic of San Marino. Univariate and multivariate analysis were conducted to better interpret the data and to build a predictive model to select, the CBU with high CD34+ content. RESULTS: Our univariate analysis shows that seasonality and the geographical area affects the quality of umbilical cord blood. Gestational age, babie's gender and birth weight have a positive correlation with CB TNC content. The babie's birth weight affects positively also CD34+ content and CBU volume while the cesarean delivery affect the CB volume only. Our predictive model, based on multivariate analysis, shows that male babie's, gestational age lower to 39 weeks, cesarean delivery and CBUs with a content of TNC higher than 3.44 × 108 (group A) have a significant higher CD34+ content than group B (female babie's, gestational age higher than 39 weeks and vaginal delivery). The group A have a 37.5% of CBUs with a concentration of CD34+ > 2 × 106, while no CBUs with high concentration of CD34+ were detect in group B. CONCLUSION: This study, conducted on a very large series of CBUs without any specific volume constraint, highlighted the prenatal and maternal factors that significantly influence the quality of the CBU collected. Specifically, it highlights that volume is not the best predictor of CD34+ CBU content; for this reason it cannot be taken into consideration alone for the analysis of the collected samples. Our final aim is to identify relevant factors, immediately available, that help to choice UCB with high CD34+ cell content, especially in simultaneous deliveries.

Bladder Cancer Chemosensitivity is Affected by Paraoxonase-2 Expression.

The goal of the current study was to identify potential roles of paraoxonase-2 in bladder carcinogenesis. T24 bladder cancer cells were transfected with plasmids inducing paraoxonase-2 silencing or overexpression. Upon the selection of clones stably down- or upregulating paraoxonase-2, cell proliferation, migration, and the production of reactive oxygen species were evaluated, before and after treatment with cisplatin and gemcitabine, used alone or in combination. The activity levels of both caspase-3 and caspase-8 were also analyzed. shRNA-mediated gene silencing and the overexpression of paraoxonase-2 revealed that the enzyme was able to promote both the proliferation and migration of T24 cells. Moreover, the knockdown of paraoxonase-2 was significantly associated with a reduced cell viability of T24 cells treated with chemotherapeutic drugs and led to both an increase of reactive oxygen species production and caspase-3 and caspase-8 activation. Conversely, under treatment with anti-neoplastic compounds, a higher proliferative capacity was found in T24 cells overexpressing paraoxonase-2 compared with controls. In addition, upon enzyme upregulation, both the production of reactive oxygen species and activation of caspase-3 and caspase-8 were reduced. Although further analyses will be required to fully understand the involvement of paraoxonase-2 in bladder tumorigenesis and in mechanisms leading to the development of chemoresistance, the data reported in this study seem to demonstrate that the enzyme could exert a great impact on tumor progression and susceptibility to chemotherapy, thus suggesting paraoxonase-2 as a novel and interesting molecular target for effective bladder cancer treatment.

Effect of High Glucose-Induced Oxidative Stress on Paraoxonase 2 Expression and Activity in Caco-2 Cells.

(1) Background: Hyperglycemia leads to several biochemical and physiological consequences, such as the generation of advanced glycation end products (AGEs) and reactive oxygen species (ROS), which are involved in the development of several human diseases. Intestinal cells are continuously exposed to pro-oxidants and lipid peroxidation products from ingested foods, and also to glyco-oxidative damage. It has been reported that free radical generation may be linked to the development of inflammation-related gastrointestinal diseases. (2) Methods: The effects of high glucose (HG) treatment (50 mM) were assessed in terms of free radical production, lipid peroxidation, and AGEs formation. Furthermore, the expression and the antiapoptotic and antioxidant activity of the paraoxonase-2 (PON2) enzyme in intestinal cells has been investigated. (3) Results: Caco-2 cells treated with media supplied with high glucose (HG) (50 mM) showed, with respect to physiological glucose concentration (25 mM), an increase in ROS production, lipid peroxidation, and AGEs formation. Moreover, a lower PON2 expression and activity in HG-treated cells was related to activation of the apoptotic pathways. (4) Conclusions: Our results demonstrated that high glucose concentrations triggered glyco-oxidative stress in intestinal cells; the downregulation of PON2 could result in a higher oxidative stress and might contribute to intestinal dysfunction.