PD-1 and PD-L1 expression in oral squamous cell carcinoma

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K11697
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Wakayama Medical University
• Principal Investigator: Tojyo Itaru 和歌山県立医科大学, 医学部, 講師 (70405439)
• Co-Investigator(Kenkyū-buntansha): 平石 幸裕 和歌山県立医科大学, 医学部, 博士研究員 (40573449)
• Research Collaborator: Nakanishi Takashi
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 口腔扁平上皮癌 / PD-L1 / p53 / CK17 / 免疫チェックポイント阻害剤

Outline of Final Research Achievements

We studied the correlation among immunohistochemical expressions of p53, CK17, PD-L1 in 48 biopsy samples of oral squamous cell carcinoma. Positive rate of p53, CK17, PD-L1(tumor cells) and PD-L1(infiltrating lymphocytes in tumor) is 63.2%, 91.7%, 48.9% and 57.1% respectively. Regarding tumor cells The expression of PD-L1 and p53 positively correlated. Because resolution time of variant p53 protein delays and the protein is accumulated into a nucleus, the variant p53 protein is identified as overexpression. Although p53 inhibits the expression of PD-L1 directly, when variant p53 which lost a function is accumulated, PD-L1 overexpresses. Thus, it is thought that the expression of p53 and PD-L1 shows positively correlation in oral squamous cell carcinoma.

Free Research Field

口腔外科学

Academic Significance and Societal Importance of the Research Achievements

学術的には口腔扁平上皮癌において、p53の発現がPD-L1の発現に正の相関を示すことは、これまで報告されたことはなく、新知見である。社会的にはPD-L1の口腔扁平上皮癌組織における発現は、ニボルマブが口腔扁平上皮癌に奏功するかどうかのバイオマーカーの一つと考えられており、口腔扁平上皮癌においてp53がPD-L1の発現に正の相関を示すことが確認されれば、口腔扁平上皮癌組織におけるp53の発現もニボルマブが患者に奏功するかどうかのバイオマーカーの一つとして考えられる可能性がある。