Integrative analysis of PD ‐L1 DNA status, mRNA status and protein status, and their clinicopathological correlation, in diffuse large B‐cell lymphoma

作者：Chenbo Sun, Yijun Jia, Weige Wang, Rui Bi, Lijing Wu, Qianming Bai, Xiaoyan Zhou · 发表于：Histopathology · 年份：2018 · DOI：10.1111/his.13765 · 被引用次数：20 · 研究领域：Lymphoma Diagnosis and Treatment、CNS Lymphoma Diagnosis and Treatment、Cancer Immunotherapy and Biomarkers

AIMS: The protein expression of programmed death-ligand 1 (PD-L1) has been recognised as being a biomarker for poor prognosis in diffuse large B-cell lymphoma (DLBCL). The aims of this study were to determine PD-L1 DNA status and mRNA status, and to explore whether they contribute to protein expression and their clinicopathological correlation in DLBCL. METHODS AND RESULTS: In this study, we used fluorescence in-situ hybridisation, RNA in-situ hybridisation and immunohistochemistry to determine PD-L1 status at three different levels in 287 DLBCL samples with follow-up. Their correlation and clinical pathological relevance were also analysed. Our results showed that 1.7% (3/175) of patients had PD-L1 DNA amplification, 19.9% (57/287) had high PD-L1 mRNA expression, and 11.8% (34/287) had high PD-L1 protein expression. Both mRNA and protein expression of PD-L1 were significantly higher in non-germinal centre B-cell-like (GCB) DLBCL than in GCB DLBCL (P < 0.05). In addition, the patients with high PD-L1 mRNA or high PD-L1 protein expression but no PD-L1 DNA amplification had significantly poorer overall survival (OS) than those with low PD-L1 expression (P < 0.05). Furthermore, we found that PD-L1 mRNA and PD-L1 protein expression were highly correlated (P = 0.012), which was observed in all three samples with DNA amplification. CONCLUSIONS: PD-L1 DNA amplification is a rare event, PD-L1 mRNA is the main contributor to the high PD-L1 protein expression, and the latter two will s...