Fig. 1. FTO is downregulated in CRC tissues, and its downregulation is associated with poor clinical prognosis.

A FTO and ALKBH5 protein levels in six paired CRC tumor (T) and adjacent normal tissues (N) determined by immunoblotting assay. B Real-time PCR analysis of mRNA expression of FTO and ALKBH5 in 40 paired CRC tumor and adjacent normal tissues from SYSUCC. GAPDH was used as a control, and comparisons were analyzed by two-tailed paired Student’s t test. C Comparison of the proteogenomic expression of FTO and ALKBH5 in tumor and normal tissue from the CPTAC Data Portal of colon cancer (https://cptac-data-portal.georgetown.edu/cptac/s/S045). D Comparison of FTO and ALKBH5 expression in normal and cancer transcriptomes obtained from TCGA and GTEx datasets of COAD and READ, analyzed by the online tool GEPIA (http://gepia.cancer-pku.cn/index.html). E, F Representative immunohistochemistry (IHC) images and IHC staining scores of FTO expression in CRC tumor tissues and paired adjacent normal tissues from cases with or without recurrence (n = 240). FTO level was classified as “high” and “low” according to the median score (≤150). Scale bar: 50 μm. G, H Representative IHC images and comparison of FTO expression in paired CRC tumor tissue and lymph node metastasis (LN M) from 113 stage III CRC patients. Scale bar: 50 μm. I Kaplan–Meier analysis of overall survival (OS) and recurrence-free survival (RFS) in CRC patients with different FTO expression levels (n = 369). *P < 0.05, **P < 0.01, ***P < 0.001.