Abstract 442: CD10 positive head and neck squamous cell carcinoma have chemoresistant and radioresistant properties.

Abstract Background: Despite recent advances in the understanding of head and neck squamous cell carcinoma (HNSCC) and the development of novel therapeutic targets, five-year survival rates for HNSCC have not improved in more than three decades. Prognosis for recurrent or metastatic HNSCC remains poor. Thus, it is important for improvement of HNSCC therapy, to research therapeutic resistant mechanism. We found CD10 positive HNSCC cells have chemoresistant and radioresistant properties. Materials and Methods: In order to investigate HNSCC chemoresistant and radioresistant properties, we used Lyoplate (company:BD).This reagent contains 242 purified monoclonal antibodies to cell surface markers and can be used for screening cells with flow cytometry. First, in three HNSCC cell lines, we compared cell surface antigen expression patterns to normal cultured cells, temporarily cisplatin exprosured cells and irradiated cells. Result: We found four cell surface markers that upragulated in cisplatin exprosured cells and irradiated cells. These are CD10, CD15s, CD146, CD282. Next, we compered these expression pattern to normal cultured cells and cisplatinresistant cells. CD10 and CD282 was upregulated. Focused on CD10, we performed cisplatin MTT assay. CD10 positive cells had more resistant property than CD10 negative cells. Conclusion: CD10 is a cell surface zinc-dependent metalloendopeptidase, which is expressed in a wide variety of normal cells. CD10 is also expressed by several solid tumors such as melanoma and several carcinomas originating from kidney, lung, skin, pancreas, prostate, liver, breast, stomach, cervix, and bladder. Several studies have shown that CD10 might be a good marker for differentiating between primary tumors and derived metastases, and therefore for evaluating tumor progression. In HNSCC, only one report demonstrated role of CD10 in the differentiation and growth of neoplastic cells and concluded that CD10 expression can have an important role in the tumor invasion, metastases. Our date is first report that CD10 positive HNSCC have chemoresisitant and radioresistant properties. This result may correlate with CD10 positive HNSCC has invasive and metastatic character. Learning Objective: We identified CD10 positive HNSCC have chemoresisitant and radioresistant properties. Citation Format: Takahito Fukusumi. CD10 positive head and neck squamous cell carcinoma have chemoresistant and radioresistant properties. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 442. doi:10.1158/1538-7445.AM2013-442