Production and significance of CCAAT enhancer binding proteins alpha and beta in sinonasal inverted papilloma
El-Hassan Shabana1, Joel Depondt1,2, Muriel Hourseau3, Francine Walker3 and Ariane Berdal1
1Laboratory of Orofacial Molecular Physiopathology, UMRS 872, CRC group-5, Paris, 2ENT Department, Bichat Hospital, University of Paris Diderot, Paris and 3Pathology Department, Bichat Hospital, University of Paris Diderot, Paris, France.
Offprint requests to: Dr. El-Hassan Shabana, Laboratoire de Physiopathologie Orofaciale Moléculaire, UMRS 872, CRC groupe-5, 15, rue de l’école de Médecine, Paris CEDEX 75005, France. e-mail: hassanshab@gmail.com; eshabana@paris7.jussieu.fr
Summary. Sinonasal inverted papilloma (SIP) is a rare benign tumor featuring increased cell proliferation, a tendency toward squamous differentiation, recurrence and malignant transformation. The CCAAT enhancer binding proteins, C/EBPs, are transcription factors regulating the proliferation and differentiation of various types of cells, including epithelial cells. We prospectively investigated the production of these transcription factors and the related proliferation and differentiation targets, keratin-10, keratin-15 and cyclin-D1, in 26 SIP patients and 8 sinonasal polyposis cases suspected for SIP. Ten of these patients had one or more recurrences over follow-up periods of one to eight years. C/EBP-alpha and C/EBP-beta proteins were not found in normal-looking sinonasal epithelial cells. The proteins and RNAs were detected in SIP and, occasionally, in polyposis tissues. The production of these factors was not significantly correlated with age, sex, site, tumor size or medical history. By contrast, correlations were found between the levels of C/EBP-alpha and keratin-10 levels and between those of C/EBP-beta and keratin-15. C/EBP-alpha levels were also significantly correlated with cyclin-D1 levels. These data suggested that the C/EBPs are implicated in the regulation of cell proliferation and differentiation in SIP. Finally, recurrent SIP produced significantly larger amounts of C/EBP-alpha than non- recurrent tumors. These results implicate CCAAT enhancer binding proteins in the pathogenesis of SIP and highlight the role of C/EBP-alpha as a candidate marker for tumor recurrence. Histol Histopathol 28, 53-60 (2013)
Key words: Sinonasal inverted papilloma, CCAT/Enhancer binding proteins, Keratin-10, Keratin-15, Cyclin-D1
DOI: 10.14670/HH-28.53