Evangelos Tsiambas1,2, Christos Riziotis3, Nicholas S Mastronikolis4, Dimitrios Peschos5, Alexandros Mortakis6, Grigorios Kyroysis6, Stylianos N Mastronikolis7, Anna Batistatou2, Andreas C Lazaris2, Efstratios Patsouris2, Vasileios Ragos8. 1. Department of Pathology-Cytology, 401 GA Hospital, Athens, Greece tsiambasecyto@yahoo.gr. 2. Department of Pathology, Medical School, University of Ioannina, Ioannina, Greece. 3. Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Athens, Greece. 4. ENT Department, Medical School, University of Patras, Patras, Greece. 5. Department of Physiology, Medical School, University of Ioannina, Ioannina, Greece. 6. LITO and IASO-REA, Private Gynaecological Centers, Athens, Greece. 7. Department of Medicine, School of Health Sciences, University of Crete, Heraklion, Greece. 8. Department of Maxillofacial, Medical School, University of Ioannina, Ioannina, Greece.
Abstract
BACKGROUND/AIM: p16 (gene locus: 9p21) tumor suppressor gene is considered an important biomarker for the progression and prognosis in a variety of malignancies and pre-cancerous lesions, including high-risk (HR-) human papilloma virus (HPV)-mediated squamous intraepithelial lesions (SILs), based on cytological and the corresponding cervical intraepithelial neoplasia (CIN) histopathological categorization. p16 acts as a cyclin-dependent kinase-4 inhibitor negatively regulating the cell cycle. In persistent HPV infection, E7 oncogenic protein binds retinoblastoma protein leading to its proteolytic transformation, also triggering E2F dissociation, which increases DNA transcription and progression to S phase. This mechanism promotes aberrant p16 over-expression. Our aim was to comparatively analyze p16 protein expression patterns in laryngeal squamous cell carcinomas (LSCC) and also in SILs. MATERIALS AND METHODS: Fifty (n=50) primary LSCCs tissues all non-HPV-dependent, and a set of 50 liquid-based SILs, were analyzed by immunohistochemistry and immunocytochemistry, respectively. Concerning the screening process in cytological slides, a novel real-time reference and calibration grid platform was implemented and employed. RESULTS: Decreased protein expression was observed in 34/50 (68%) tissues regarding LSCCs. Overall p16 expression was associated to smoking status of the patients (p=0.001), and also with the p-stage of the examined malignancies (p=0.033). A strong statistical significance was assessed correlating LSIL/HSIL cases with a progressive p16 over expression (p=0.001), also reflecting a higher CIN diagnosis (p=0.001). CONCLUSION: p16 down-regulation is a frequent genetic event in LSCCs, which is associated with advanced disease. In contrast to this, p16 over-expression triggered by a specific molecular mechanism shows a strong relationship with a progressively aggressive phenotype due to upgraded SIL/CIN cervical categorization. The first described application of the grid platform demonstrated a considerable improvement in the immunocytochemistry slide screening process enhancing the diagnostic reliability. Copyright
BACKGROUND/AIM: p16 (gene locus: 9p21) tumor suppressor gene is considered an important biomarker for the progression and prognosis in a variety of malignancies and pre-cancerous lesions, including high-risk (HR-) human papilloma virus (HPV)-mediated squamous intraepithelial lesions (SILs), based on cytological and the corresponding cervical intraepithelial neoplasia (CIN) histopathological categorization. p16 acts as a cyclin-dependent kinase-4 inhibitor negatively regulating the cell cycle. In persistent HPV infection, E7 oncogenic protein binds retinoblastoma protein leading to its proteolytic transformation, also triggering E2F dissociation, which increases DNA transcription and progression to S phase. This mechanism promotes aberrant p16 over-expression. Our aim was to comparatively analyze p16 protein expression patterns in laryngeal squamous cell carcinomas (LSCC) and also in SILs. MATERIALS AND METHODS: Fifty (n=50) primary LSCCs tissues all non-HPV-dependent, and a set of 50 liquid-based SILs, were analyzed by immunohistochemistry and immunocytochemistry, respectively. Concerning the screening process in cytological slides, a novel real-time reference and calibration grid platform was implemented and employed. RESULTS: Decreased protein expression was observed in 34/50 (68%) tissues regarding LSCCs. Overall p16 expression was associated to smoking status of the patients (p=0.001), and also with the p-stage of the examined malignancies (p=0.033). A strong statistical significance was assessed correlating LSIL/HSIL cases with a progressive p16 over expression (p=0.001), also reflecting a higher CIN diagnosis (p=0.001). CONCLUSION:p16 down-regulation is a frequent genetic event in LSCCs, which is associated with advanced disease. In contrast to this, p16 over-expression triggered by a specific molecular mechanism shows a strong relationship with a progressively aggressive phenotype due to upgraded SIL/CIN cervical categorization. The first described application of the grid platform demonstrated a considerable improvement in the immunocytochemistry slide screening process enhancing the diagnostic reliability. Copyright