Overexpression of nicotinamide N-methyltransferase in HSC-2 OSCC cell line: effect on apoptosis and cell proliferation
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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 β-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.
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.
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.
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.
KeywordsNNMT Survivin Cell growth Tumorigenicity Oral cancer
This study was supported by grants from Marche Polytechnic University.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
For this type of study, formal consent is not required.
- 4.Aksoy S, Szumlanski CL, Weinshilboum RM (1994) Human liver nicotinamide N-methyltransferase. cDNA cloning, expression, and biochemical characterization. J Biol Chem 269:14835–14840Google Scholar
- 6.Pozzi V, Sartini D, Morganti S, Giuliante R, Di Ruscio G, Santarelli A, Rocchetti R, Rubini C, Tomasetti M, Giannatempo G, Orlando F, Provinciali M, Lo Muzio L, Emanuelli M (2013) RNA-mediated gene silencing of nicotinamide N-methyltransferase is associated with decreased tumorigenicity in human oral carcinoma cells. PLoS One 8:e71272CrossRefGoogle Scholar
- 9.Sartini D, Muzzonigro G, Milanese G, Pozzi V, Vici A, Morganti S, Rossi V, Mazzucchelli R, Montironi R, Emanuelli M (2013) Upregulation of tissue and urinary nicotinamide N-methyltransferase in bladder cancer: potential for the development of a urine-based diagnostic test. Cell Biochem Biophys 65:473–483CrossRefGoogle Scholar
- 11.Emanuelli M, Santarelli A, Sartini D, Ciavarella D, Rossi V, Pozzi V, Rubini C, Lo Muzio L (2010) Nicotinamide N-Methyltransferase upregulation correlates with tumour differentiation in oral squamous cell carcinoma. Histol Histopathol 25:15–20Google Scholar
- 12.Sartini D, Pozzi V, Renzi E, Morganti S, Rocchetti R, Rubini C, Santarelli A, Lo Muzio L, Emanuelli M (2012) Analysis of tissue and salivary nicotinamide N-methyltransferase in oral squamous cell carcinoma: basis for the development of a noninvasive diagnostic test for early-stage disease. Biol Chem 393:505–511CrossRefGoogle Scholar
- 15.Wu Y, Siadaty MS, Berens ME, Hampton GM, Theodorescu D (2008) Overlapping gene expression profiles of cell migration and tumor invasion in human bladder cancer identify metallothionein 1E and nicotinamide N-methyltransferase as novel regulators of cell migration. Oncogene 27:6679–6689CrossRefGoogle Scholar
- 18.Parsons RB, Aravindan S, Kadampeswaran A, Evans EA, Sandhu KK, Levy ER, Thomas MG, Austen BM, Ramsden DB (2011) The expression of nicotinamide N-methyltransferase increases ATP synthesis and protects SH-SY5Y neuroblastoma cells against the toxicity of complex I inhibitors. Biochem J 436:145–155CrossRefGoogle Scholar
- 22.Pozzi V, Sartini D, Rocchetti R, Santarelli A, Rubini C, Morganti S, Giuliante R, Calabrese S, Di Ruscio G, Orlando F, Provinciali M, Saccucci F, Lo Muzio L, Emanuelli M (2015) Identification and characterization of cancer stem cells from head and neck squamous cell carcinoma cell lines. Cell Physiol Biochem 36:784–798CrossRefGoogle Scholar
- 23.De Maria S, Pannone G, Bufo P, Santoro A, Serpico R, Metafora S, Rubini C, Pasquali D, Papagerakis SM, Staibano S, De Rosa G, Farina E, Emanuelli M, Santarelli A, Mariggiò MA, Lo Russo L, Lo Muzio L (2009) Survivin gene-expression and splicing isoforms in oral squamous cell carcinoma. J Cancer Res Clin Oncol 135:107–116CrossRefGoogle Scholar
- 30.Wang L, Zhang GM, Feng ZH (2003) Down-regulation of survivin expression reversed multidrug resistance in adriamycin-resistant HL-60/ADR cell line. Acta Pharmacol Sin 24:1235–1240Google Scholar
- 33.Mahotka C, Wenzel M, Springer E, Gabbert HE, Gerharz CD (1999) Survivin-deltaEx3 and survivin-2B: two novel splice variants of the apoptosis inhibitor survivin with different antiapoptotic properties. Cancer Res 59:6097–6102Google Scholar