Peripheral Blood Leukocyte N6-methyladenosine is a Noninvasive Biomarker for Non-small-cell Lung Carcinoma

Yuqing Pei; Xiaoying Lou; Kexin Li; Xiaotian Xu; Ye Guo; Danfei Xu; Zhenxi Yang; Dongsheng Xu; Wei Cui; Donghong Zhang

doi:10.2147/OTT.S267344

Peripheral Blood Leukocyte N6-methyladenosine is a Noninvasive Biomarker for Non-small-cell Lung Carcinoma

Onco Targets Ther. 2020 Nov 19:13:11913-11921. doi: 10.2147/OTT.S267344. eCollection 2020.

Authors

Yuqing Pei¹, Xiaoying Lou¹, Kexin Li¹, Xiaotian Xu¹, Ye Guo², Danfei Xu¹, Zhenxi Yang¹, Dongsheng Xu³, Wei Cui¹, Donghong Zhang⁴

Affiliations

¹ State Key Laboratory of Molecular Oncology, Department of Clinical Laboratory, National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, People's Republic of China.
² Department of Laboratory Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, People's Republic of China.
³ Hematopathology Program, CBL Path, Inc, Rye Brook, NY 10753, USA.
⁴ Center for Molecular and Translational Medicine, Georgia State University, Research Science Center, Atlanta, GA 30303, USA.

Abstract

Background: N6-methyladenosine (m6A) triggers a new layer of epi-transcription. However, the potential noninvasive screening and diagnostic value of peripheral blood m6A for cancer are still unknown. Here, we intend to investigate whether leukocyte m6A can be a novel biomarker for non-small-cell lung cancer (NSCLC).

Materials and methods: Peripheral blood was collected from 119 NSCLC patients and 74 age-matched healthy controls. Total RNA was isolated from leukocytes for m6A measurement, and clinical information of participants was reviewed. The sensitivity, specificity, and area under the curve (AUC) of m6A for cancer diagnosis were evaluated by the receiver-operating characteristic (ROC) curve analysis. Flow cytometry and the Human Protein Atlas (HPA) database were used to characterize m6A in leukocyte differentials. Pearson's correlation was applied to indicate the relationship between m6A level and hematology variables. qPCR and bioinformatic analysis were used to identity the expression of m6A regulators in leukocyte.

Results: Leukocyte m6A was significantly elevated in 119 NSCLC patients compared with 74 healthy controls (P<0.001). We did not find significant association between m6A and age or gender. Elevated m6A level in NSCLC was associated with tumor stage (P<0.05) and tumor differentiation (P<0.05), and was significantly reduced after surgery (P<0.01). ROC curve analysis revealed that leukocyte m6A could significantly discriminate patients with lung adenocarcinoma (LUAD) (AUC=0.736, P<0.001) and lung squamous cell carcinoma (LUSC) (AUC=0.963, P<0.001) from healthy individuals. m6A displayed superior sensitivity (100%) and specificity (85.7%) for LUSC than squamous cell carcinoma (SCC) antigen and cytokeratin fragment 211 (Cyfra211). Flow cytometry analysis showed m6A modification was mainly localized on T cells and monocytes among leukocyte differentials. Leukocyte m6A was positively correlated with the number of lymphocytes and negatively correlated with monocytes in NSCLC but not in healthy controls. qPCR and bioinformatic analysis showed that elevated leukocyte m6A in NSCLC was caused by upregulated methyltransferase complex and downregulated FTO and ALKBH5.

Conclusion: Leukocyte m6A represents a potential noninvasive biomarker for NSCLC screening, monitoring and diagnosis.

Keywords: N6-methyladenosine; biomarker; leukocyte; lung cancer.

Grants and funding

This work was supported by CAMS Innovation Fund for Medical Sciences (No. 2019-I2M-2-002); and by National Key R&D Program of China (No. 2018YFC1315000/2018YFC1315002).