Background: N6-methyladenosine (m6A) RNA methylation and tumor immune microenvironment played crucial roles in cancer development. However, their association in gliomas remains to be fully elucidated.
Methods: A total of 2144 glioma patients from CGGA, TCGA, and Rembrandt databases were extracted in our study, in which 325 were set as the training cohort and 1819 were defined as the validation cohort. Survival differences evaluated by Kaplan-Meier analysis between groups. Patients were clustered into subgroups by consensus clustering. ESTIMATE algorithm was applied to calculate immune and stroma scores. The infiltration of immune cells was characterized by TIMER algorithm. The risk signature was constructed by multivariate Cox regression analysis.
Results: Nineteen m6A regulators were highly expressed in glioma tissues. The expression of m6A regulators was associated with prognoses, grade, isocitrate dehydrogenase (IDH) status, and 1p19q status of gliomas. Two subgroups were identified by consensus clustering, in which cluster 1 was associated with favorable prognosis, high stroma and immune scores, and high immune infiltration. When the patients were divided into high risk and low risk groups based on their risk scores, we found that patients in the high risk group had poor prognoses. Besides, patients in the high risk group had a higher stroma and immune scores, and higher abundance of immune infiltration. These results were further verified in the validation cohort, which contained three independent datasets. Moreover, patients in the low risk group enjoyed better prognoses without chemoradiotherapy or single chemotherapy.
Conclusion: Our study revealed that m6A regulators could predict the prognosis and therapeutic efficacy, and were also associated with the immune microenvironment in gliomas.
Keywords: N6-methyladenosine methylation; brain tumor; chemoradiotherapy; glioma; immune infiltration; immune microenvironment.
Copyright © 2020 Xu, Tang, Dai, Luo and Liu.