6th ICHNO Abstract Book

page 50 6 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 16 – 18 March 2017 Barcelona, Spain __________________________________________________________________________________________ Results 6th ICHNO

Purpose or Objective Oral squamous cell carcinoma (OSCC) is the most common cancer of oral cavity with poor prognosis and survival rates. The PI3K/AKT/mTOR signaling pathway plays a central role in cell proliferation, migration, survival and angiogenesis regulation. Recently, the aberrant activation of mTOR has been connected with poor prognosis in various cancers including OSCC, becoming a promising anti-cancer target therapy. The main objective of this study was to evaluate, in vitro , the therapeutic efficacy of a mTOR inhibitor, everolimus (EVE), in OSCC and the related underlying mechanisms. Material and Methods Two OSCC cell lines were maintained in culture, BICR-10 ( in situ ) and the HSC-3 (high metastatic potential) cells, in absence and in presence of increasing concentrations of EVE, 10-50 µM. Cell viability was assessed by the rezasurin metabolic assay and cell death by optical microscopy (May-Grünwald-Giemsa staining) and flow cytometry (Annexin V-Propidium Iodide staining). Cell cycle was assessed by flow cytometry using PIRNase kit. The Caspases, BAX, BCL-2, Cyclin D1 and E-cadherin expression levels were also evaluated by flow cytometry. Western blot was used to evaluate the expression of total and phosphorylated AKT and P70S6K as well as the total expression of Integrin Beta 1 and Beta 1 Catenin. Cell migration was evaluated by the wound healing assay. Enzymatic activity of metalloproteinase (MMP)-2 and -9 was evatuated by zymography. Results were statistical analyzed. Results Our results showed that EVE induces antiproliferative and cytotoxic effects in a dose, time and cell type dependent manner. The HSC-3 cells were the more sensitive to EVE, with IC50 at 48h around 35µM. In HSC-3 cells EVE induced cell death mainly by later apoptosis/necrosis associated to the increase in BAX/BCL-2 ratio and Caspases levels. Furthermore, EVE induced cell cycle arrest in S phase with the increase in Cyclin D1 expression. EVE also reduced migration and invasion in HSC-3 cells dependent on the following: increase of E-Cadherian expression and decrease of both Integrin beta 1 expression and MMP-2 enzymatic activity. Conclusion In this work, we did not observe significant statistical alterations in the OSCC in situ cells treated with EVE. However, in OSCC cells with high metastatic potential we observed that EVE induced a significant statistical decrease in cell proliferation, migration, invasion and an increase in cell death. These results suggest that EVE constitutes a promising therapeutic approach in OSCC with high metastatic potential. PO-105 Is there justification for age bias in HPV p16 testing for Oropharyngeal Squamous Cell Carcinoma? S. McCauley 1 , P. McCloskey 1 , C. Lyons 1 , K. Brown 1 , K. Rooney 1 , F. Houghton 1 1 Northern Ireland Cancer Centre, Clinical Oncology, Belfast, United Kingdom Purpose or Objective Human Papilloma Virus (HPV) p16 is a causative agent in a biologically distinct subset of Oropharyng eal Squamous Cell Carcinoma (OPSCC), with a highly favourable prognosis 1 . Updated guidelines pertaining to OPSCC now require universal HPV p16 immunohistochemistry testing 2 . Using this as our standard, we undertook a retrospective audit of all OPSCC treated in our centre during 2015, identifying the prevalence of OPSCC in our population, p16 status, the proportion of p16 positivity, and their age-gender demographics. We

To date, tumor biopsies from 24 OPSCC patients have been xenografted resulting in xenograft tumor growth in 15 cases (63 %). PDX models were established from OPSCC patients with HPV-positive and HPV-negative disease as well as a wide range of tobacco exposure. Most PDX tumors retained the histological appearance of squamous cell carcinoma and immunoprofile of the original tumor. Other tumors adopted a lymphoproliferative appearance. Low- dose irradiation of PDX tumors resulted in a reproducible growth delay. Conclusion It is possible to generate PDX models that represent the clinical heterogeneity of disease with a satisfactory success rate. Most PDX models retain the characteristics of the original tumor. The PDX model is suitable for radiotherapy research.

PO-104 Everolimus in oral cancer: a potential therapeutic approach dependent on cell type? C. Domingues 1,2,3 , P. Matafome 4 , S. Neves 2,3 , M. Laranjo 3,5 , R. Seiça 4 , M.F. Botelho 3,5 , A.B. Sarmento-Ribeiro 2,3 , M. Dourado 1,3 1 Faculty of Medicine- University of Coimbra- Portugal, Pathophysiology Curricular Unit- Dental Medicine, Coimbra, Portugal 2 Faculty of Medicine- University of Coimbra- Portugal, Laboratory of Oncobiology and Hematology- Applied Molecular Biology and University Clinic of Hematology, Coimbra, Portugal 3 Faculty of Medicine- University of Coimbra- Portugal, Center of Investigation on Environment Genetics and Oncobiology CIMAGO, Coimbra, Portugal 4 Faculty of Medicine- University of Coimbra- Portugal, Laboratory of Physiology- Institute for Biomedical Imaging and Life Sciences IBILI, Coimbra, Portugal 5 Faculty of Medicine- University of Coimbra- Portugal, Biophysics Institute- Institute for Biomedical Imaging and Life Sciences IBILI, Coimbra, Portugal