title: Role of nicotinamide N-methyltransferase in non-small cell lung cancer: in vitro effect of shRNA-mediated gene silencing on tumourigenicity.
abstract: Lung cancer is the second most commonly diagnosed neoplasm, and represents the leading cause of tumour death worldwide. As patients are often diagnosed at a late stage, current therapeutic strategies have limited effectiveness and the prognosis remains poor. Successful treatment depends on early diagnosis and knowledge concerning molecular mechanisms underlying lung carcinogenesis. In the present study, we focused on nicotinamide N-methyltransferase (NNMT), which is overexpressed in several malignancies. First, we analysed NNMT expression in a cohort of 36 patients with non-small cell lung cancer (NSCLC) by immunohistochemistry. Subsequently, we examined NNMT expression levels in the human lung cancer cell line A549 by Real-Time PCR, Western blot and catalytic activity assay, and evaluated the effect of NNMT knockdown on cell proliferation and anchorage-independent cell growth by MTT and soft agar colony formation assays, respectively. NSCLC displayed higher NNMT expression levels compared to both tumour-adjacent and surrounding tissue. Moreover, shRNA-mediated gene silencing of NNMT led to a significant inhibition of cell proliferation and colony formation ability on soft agar. Our results show that the downregulation of NNMT significantly reduced in vitro tumorigenicity of A549 cells and suggest that NNMT could represent an interesting molecular target for lung cancer therapy.
authors.forename: Davide
authors.initials: D
authors.lastname: Sartini
authors.forename: Riccardo
authors.initials: R
authors.lastname: Seta
authors.forename: Valentina
authors.initials: V
authors.lastname: Pozzi
authors.forename: Stefano
authors.initials: S
authors.lastname: Morganti
authors.forename: Corrado
authors.initials: C
authors.lastname: Rubini
authors.forename: Antonio
authors.initials: A
authors.lastname: Zizzi
authors.forename: Marco
authors.initials: M
authors.lastname: Tomasetti
authors.forename: Lory
authors.initials: L
authors.lastname: Santarelli
authors.forename: Monica
authors.initials: M
authors.lastname: Emanuelli
mesh_terms: D000328:Adult; D000368:Aged; D063646:Carcinogenesis / Q000473:pathology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000473:pathology*; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000201:enzymology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D050903:Nicotinamide N-Methyltransferase / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism*
chemical_list: D034741:RNA, Small Interfering; D050903:Nicotinamide N-Methyltransferase