Clinicopathologic implications of the miR-197/PD-L1 axis in oral squamous cell carcinoma

• Published in: Oncotarget Vol. 8; no. 39; pp. 66178 - 66194
• Main Authors: Ahn, Hyein, Yang, Jeong Mi, Kim, Hyojin, Chung, Jin-Haeng, Ahn, Soon-Hyun, Jeong, Woo-Jin, Paik, Jin Ho
• Format: Journal Article
• Language: English
• Published: United States Impact Journals LLC 12.09.2017
• Subjects: Research Paper; PD-L1; microRNA; tumor-infiltrating lymphocytes; oral squamous cell carcinoma; miR-197
• ISSN: 1949-2553; 1949-2553
• DOI: 10.18632/oncotarget.19842

Immune escape of a tumor from tumor-infiltrating lymphocytes (TILs) is induced by PD-L1, which is suppressed by miR-197. We investigated the clinicopathologic implications of the miR-197/PD-L1 axis and its effects on TILs and the clinicopathologic features of oral squamous cell carcinoma (OSCC). We used RT-PCR and immunohistochemistry in 68 OSCC patients to analyze the correlations between tumoral expression of miR-197 and PD-L1 and the degree of tumoral invasion by TILs (CD3+, CD4+, CD8+, PD-1+, FoxP3+, and CD20+ lymphocytes). PD-L1 levels correlated inversely with miR-197 but correlated positively with TILs. The aggressive features of OSCC, including high stage, angiolymphatic invasion, perineural invasion, and death, were associated with TIL depletion. High T stage (T4) tumors also had low PD-L1 but had high miR-197 expression. In a univariate survival analysis of the full cohort, high miR-197 was associated with poor overall survival, whereas high PD-L1 expression (2+) associated with good overall survival. In a multivariate analysis stratified based on miR-197 (median), high PD-L1 expression (2+) was an independent favorable prognostic factor for overall survival ( = 0.040) in the miR-197 subgroup but not the miR-197 subgroup. These findings may have clinicopathologic implications for the miR-197/PD-L1 axis and TILs in OSCC.