Fig 2: Protein expression of glucose-6-phosphate isomerase (GPI) in clinical specimens of lung adenocarcinoma (LUAD). (A) Immunohistochemical staining of GPI was performed in tumor tissues (n = 46) and paracarcinoma tissues (n = 46). Representative images are shown. Score bars, 50 μm. (B) Staining was quantified, as shown. The dot plot depicts the means and standard deviation of 46 images of tumor tissues and adjacent normal tissues. *p < 0.05.

Fig 3: Validation of the high expression of glucose-6-phosphate isomerase (GPI) in lung adenocarcinoma (LUAD) using independent external databases and cell lines. (A–D) Expression of GPI in tumor and unpaired paracarcinoma tissues of the GSE10072, GSE32863, GSE7503, and GSE30219 datasets in the Gene Expression Omnibus (GEO) database. (E–G) Expression level of GPI in tumor and paired adjacent tissues in the GSE10072, GSE32863, and GSE7503 datasets of the GEO database. (H) Transcriptional level of GPI in different non-small-cell lung cancer (NSCLC) cell lines. (I) Validation of the expression level of GPI in LUAD using the Human Protein Atlas database (immunohistochemistry). (J) Western blot detecting the protein expression level of GPI in different NSCLC cell lines. ***p < 0.001.

Fig 4: The expression level of glucose-6-phosphate isomerase (GPI) in different human cancers. (A) Increased or decreased GPI expression in datasets of different cancers compared with normal tissues in the Oncomine database. (B) TIMER was used to detect the expression levels of GPI in different tumors in The Cancer Genome Atlas (TCGA) database. (C) The cBioPortal OncoPrint map shows the distribution of GPI genome changes in lung adenocarcinoma (LUAD) patients. (D–J) Expression level of GPI in normal tissues and paired adjacent tissues [unmatched tissues (D) and matched tissues (E)] and the tumor tissues from patients with different clinical characteristics in TCGA [clinical stage (F), N stage (G), primary therapy outcome (H), smoking pack-years (I), and OS event (J)]. **p < 0.01, ***p < 0.001.

Fig 5: Diagnostic value of glucose-6-phosphate isomerase (GPI) expression in lung adenocarcinoma (LUAD). (A) Receiver operating characteristic (ROC) curve analysis for GPI expression in LUAD and adjacent tissue. (B) Nomogram survival prediction chart for predicting the 1-, 3-, and 5-year overall survival rates.