Elevated RECQL1 expression predicts poor prognosis and associates with tumor immune infiltration in low-grade glioma.

Background: Dysregulation of RecQ protein-like 1 (RECQL1), a member of the RecQ DNA helicase, has been determined to participate in malignant process of numerous tumors such as immunosuppression and proliferation and may serve as a biomarker for certain malignancies. Nevertheless, whether there is a similar association between RECQL1 and low-grade glioma (LGG) is uncertain. We therefore turned our attention to exploring the association of RECQL1 with tumor immune infiltration and prognostic significance in LGG. Methods: The differential expression analysis of the RecQ DNA helicases was conducted through the GLIOVIS database and GSE4290 dataset, and verified by the Gene Expression Profiling Interactive Analysis 2 database. Kaplan-Meier plots, Univariate and multivariate Cox regression analysis were employed to assess the prognostic value of RECQL1 expression level and other six variables in LGG patients, and subsequently an efficient nomogram model was generated for clinical prediction. Tumor Immune Estimation Resource database and the single sample Gene Set Enrichment Analysis were used to assess the correlation between RECQL1 and immune infiltration of LGG. The biological processes that may be related to RECQL1 in LGG were learned through functional enrichment analysis by Gene Set Enrichment Analysis software. Results: Among the five RecQ DNA helicases detected, only RECQL1 was over-expression in LGG with the most convincing evidence (log2FoldChange >1.5, q value <0.01). High RECQL1 expression demonstrated worse overall survival and progression-free survival of LGG patients (P<0.05). Dysregulation of RECQL1 was an independent prognostic indicator for outcomes of LGG (HR >1.4, P<0.05). RECQL1 may participates in the carcinogenic pathways of LGG such as adherens junction and JAK-STAT signaling pathways. The transcription expression level of RECQL1, was obviously associated with tumor immune infiltrating cells and their marker genes. Conclusions: High RECQL1 expression detected in LGG not only implies adverse clinical outcome of patients, but also correlates with tumor immune infiltration and certain oncogenic pathways. Our study proposes potential novel biomarker and therapeutic target for the treatment of LGG patients.