Fig 2: Association of CLIC1 with drug sensitivity. (A–G) Different IC50 values of (A) camptothecin, (B) cisplatin, (C) doxorubicin, (D) erlotinib, (E) etoposide, (F) paclitaxel and (G) rapamycin in highly and lowly expressed CLIC1 tumors. (H,I) Association of CLIC1 with AUC values of (H) CTRP- and (I) PRISM-derived drugs and different AUC values between down- and upregulated CLIC1 samples. The Student’s t-test was used to compare the statistical difference between two groups. ***p-value < 0.001.

Fig 3: Genomic alterations and DNA methylation associated with CLIC1. (A,B) Gene gains and losses in glioma tumors with upregulated CLIC1. Red, gains; blue, losses. The significant cutoff was set as q-value of 0.25. (C,D) Gene gains and losses in tumors with downregulated CLIC1. (E) Somatically mutant genes in highly or lowly expressed CLIC1 tumors. Genes are ranked by mutant frequency. (F–J) Different TMB, aneuploidy score, CTA score, fraction of genome altered and number of segments in two groups. (K) Correlation between CLIC1 methylation and its expression across glioma tumors. The Student’s t-test was used to compare the differences between two groups in terms of TMB, aneuploidy score, CTA score, fraction of genome altered, and the number of segments. The correlation between CLIC1 methylation and its expression across glioma tumors was assessed using the Spearman test. ***p-value < 0.001.

Fig 4: CLIC1 is a therapeutic vulnerability of glioma. (A,B) RT-qPCR for measurement of CLIC1 expression in U251 and U373 cells transfected with si-NC or si-CLIC1. (C) The protein level of the CLIC1 in glioma cells transfected with si-CLIC1 and a control sequence were assessed by Western blotting. β-actin was the loading control. (D–F) Flow cytometry for detection of apoptosis of si-NC or si-CLIC1-transfected U251 and U373 cells. (G–I) Wound healing for evaluation of cell mobility of si-NC- or si-CLIC1-transfected U251 and U373 cells. The Student’s t-test and one-way analysis of variance (ANOVA) were respectively used to compare the statistical differences between two groups and three or more groups. Bar, 200 μm. ***p-value < 0.001.

Fig 5: Upregulated CLIC1 correlates to undesirable prognostic outcomes of glioma. (A–C) Different OS, DSS and PFS outcomes in lowly and highly expressed CLIC1 patients as well as one-, three- and 5-year ROCs in TCGA cohort. OS, DSS and PFS analyses were conducted through Kaplan–Meier curves and log-rank test utilizing survival package. OS, overall survival; DSS, disease-specific survival; PFS, progression-free survival; ROC, receiver operating characteristic.