RT Journal Article SR Electronic T1 Comparative p16INK4A Expression in Laryngeal Carcinoma and Cervical Cancer Precursors: A Real-time Grid-based Immunocytochemistry Analysis JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 5805 OP 5810 DO 10.21873/anticanres.12920 VO 38 IS 10 A1 EVANGELOS TSIAMBAS A1 CHRISTOS RIZIOTIS A1 NICHOLAS S. MASTRONIKOLIS A1 DIMITRIOS PESCHOS A1 ALEXANDROS MORTAKIS A1 GRIGORIOS KYROYSIS A1 STYLIANOS N. MASTRONIKOLIS A1 ANNA BATISTATOU A1 ANDREAS C. LAZARIS A1 EFSTRATIOS PATSOURIS A1 VASILEIOS RAGOS YR 2018 UL http://ar.iiarjournals.org/content/38/10/5805.abstract AB 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.