Immune signature of T follicular helper cells predicts clinical prognostic and therapeutic impact in lung squamous cell carcinoma.

Lung cancer is the leading reason of cancer-related death from cancer globally for both men and women. Recently, tumor immune heterogeneity has been implicated in cancer clinical outcome. However, this prognostic significance of immune cell types in lung squamous cell carcinoma (LUSC) is unclear and should be systematically investigated. Two microarray datasets (GSE67061 and GSE2088) from the Gene Expression Omnibus (GEO) database were downloaded and then integrated to estimate the fraction of 22 immune cell types by CIBERSORT algorithm. To validate the estimation for LUSC, the data of LUSC TCGA were also assessed in order to determine specific infiltrating immune cell type closely correlated with LUSC patients' survival determined by Cox regression analyses. Immunotherapeutic and chemotherapeutic response between the LUSC patients were also evaluated. T follicular helper cells were obtained by Cox regression analysis to develop the prognostic signature. According to this immune prognostic risk score, immune signature of T follicular helper cells is an independent and specific prognostic signature for predictions of LUSC patient overall survival. Moreover, high-risk group exhibited less expression of N6-methyladenosine (m6A) RNA methylation regulator including ALKBH5, METTL3, HNRNPC and KIAA1429 and was much more sensitive to immunotherapy and chemotherapy. This study suggests that this immune signature is important determinants of prognosis in LUSC and may provide potential prognostic biomarker or therapeutic target for immunotherapeutic and chemotherapeutic development.