title: NSP 5a3a: a potential novel cancer target in head and neck carcinoma.
abstract: NSP 5a3a along with three other distinct though similar splice variants were initially identified corresponding to locus HCMOGT-1 on chromosome 17p11.2 [1]. Secondary structure analysis of the novel structural protein (NSP) isoforms revealed similarity to Spectrin like proteins containing coiled coil domains [1]. The NSP 5a3a isoform had been found to be highly expressed in-vitro in particular cancer cell lines while very low to un-detectable levels in normal body tissues [1]. Subsequent investigation of this isoform revealed its novel interaction with B23 [2], a multifunctional nucleolar protein involved in ribosome biogenesis, rRNA transcription, mitosis, cell growth control, and apoptosis [3]. Subsequent investigation, elucidated NSP 5a3a's potential involvement in cellular processes such as ribosome biogenesis and rRNA processing by validating NSP 5a3a's novel interaction with B23 and ribonuclear protein hnRNP-L possibly implicating NSP 5a3a's involvement in cellular activities such as RNA metabolism and processing [4]. In this preliminary investigation, we wanted to observe the effect that over-expressing NSP 5a3a may have on cell cycle and its potential application in cancer treatment in aggressive cancers such as head and neck carcinomas. Over-expressed NSP 5a3a in HN30 cells induced a significant degree of apoptosis, an average of a 10.85 fold increase compared to controls 3 days post-transfection. This effect was more significant then the apoptosis observed between Fadu cells over-expressing NSP 5a3a and its controls. Though, the apoptosis induced in the WI38 control cell line showed an average of a 13.2 fold increase between treated and controls comparable to the HN30 cell line 3 days post-transfection. Molecular analysis indentified a novel p73 dependent mechanism independent of p53 and caspase 3 activity through which NSP 5a3a is inducing apoptosis. We propose NSP 5a3a as a potential therapeutic target for site directed cancer treatment in perhaps certain head and neck carcinomas by induction of apoptosis.
authors.forename: Luca
authors.initials: L
authors.lastname: D'agostino
authors.forename: Antonio
authors.initials: A
authors.lastname: Giordano
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology*; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D005347:Fibroblasts / Q000378:metabolism; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D005822:Genetic Vectors; D006258:Head and Neck Neoplasms / Q000235:genetics / Q000473:pathology*; D006801:Humans; D008168:Lung / Q000166:cytology / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics*; D014162:Transfection; D014407:Tumor Cells, Cultured; D000096985:Calponins
chemical_list: D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D009687:Nuclear Proteins; C486588:SPECC1 protein, human; D000096985:Calponins