title: PAX8 expression in human bladder cancer.
abstract: PAX8 is a transcription factor with a role in ontogenesis of the urinary tract. The aim of the present investigation was to investigate PAX8 expression in normal bladder and in non-invasive urothelial tumours. Nine cases of normal urothelial mucosa, 2 cases of papillary urothelial neoplasia of low malignant potential, 12 cases of low grade non-invasive papillary urothelial carcinoma and 16 cases of high grade non-invasive papillary urothelial carcinoma were investigated by immunohistochemistry. PAX8 mRNA expression was evaluated by RT-PCR in a different set of normal bladder mucosas and tumours. In addition, PAX8 expression was evaluated by RT-PCR in bladder from 2 human embryos and in several continuous cell lines derived from bladder tumours (5637, RT-112, TCC-SUP, HT 1376). In immunohistochemical studies, PAX8 was expressed in 28 out of 30 non-invasive urothelial tumours, but not in the normal adult bladders. In RT-PCR studies, PAX8 was expressed in 13 out of 13 bladder tumours but not in the 6 normal bladder mucosa. Contrary to that in adults, PAX8 was expressed in 2 cases of bladder mucosa from 16-week-old embryos. PAX8 was expressed in all the cell lines from bladder tumours. Both in the bladder tumours and cell lines PAX8 expression was highly heterogeneous in terms of the splicing isoforms. Treatment of cell lines with sodium butyrate (NaB) induced several changes of the splicing isoforms. Therefore, only subsets of molecular events that determine the PAX8 mRNA splicing heterogeneity in bladder tumours are sensitive to NaB treatment.
authors.affiliation: Istituto di Genetica, Policlinico Universitario di Udine, Napoli, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Pellizzari
authors.forename: Cinzia
authors.initials: C
authors.lastname: Puppin
authors.forename: Laura
authors.initials: L
authors.lastname: Mariuzzi
authors.forename: Francesca
authors.initials: F
authors.lastname: Saro
authors.forename: Maura
authors.initials: M
authors.lastname: Pandolfi
authors.forename: Roberto
authors.initials: R
authors.lastname: Di Lauro
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Beltrami
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Damante
mesh_terms: D017398:Alternative Splicing; D045744:Cell Line, Tumor; D003577:Cytochrome P-450 Enzyme System; D006801:Humans; D007150:Immunohistochemistry; D006899:Mixed Function Oxygenases; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D001743:Urinary Bladder / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors; D012333:RNA, Messenger; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C436302:phenylacetate 2-hydroxylase