Expression and clinical significance of calumenin in brain gliomas

Abstract

Objective To detect the expression of calumenin (CALU) in human brain glioma samples, to explore its effect on the patient′s outcome, and to analyze the related biological functions of the genes co-expressed with CALU. Methods A retrospective analysis was conducted on CALU sequencing expression and clinical data of 288 glioma patients with positive CALU expression in the mRNAseq_325 database of Chinese Glioma Genome Atlas (CGGA). We analyzed the effects of CALU expression levels on survival in different types of glioma patients. The multivariate Cox regression method was used to determine the relevant factors affecting the survival of glioma patients. Pearson correlation analysis was employed to screen the related genes co-expressed with CALU and their biological functions were explored using the online bioinformatic analysis tools. Results Among the 288 patients, the expression of CALU was 4.74±0.68, 5.49±1.12 and 6.17±0.94 in World Health Organization (WHO) grade Ⅱ, Ⅲ, and Ⅳ patients respectively, and 6.13±1.17 and 5.08±0.76 in isocitrate dehydrogenase l (IDH1) wild-type and IDH1 mutant gliomas respectively, and 5.79±0.07 and 4.71±0.07 in gliomas with 1p/19q non-codeletion and 1p/19q co-deletion. The comparative differences in the above indicators were statistically significant (all P 0.05). The median survival of CALU patients with high and low expression levels (144 cases in each) was 13.0(1-132)months and 82.5(2-149)months, respectively, which had statistically significant difference (P<0.01). In patients with WHO grade Ⅱ-Ⅳ gliomas, the high expression of CALU mainly reduced the survival time of grade Ⅲ and Ⅳ patients (both P<0.01). The multivariate Cox regression analysis showed that CALU expression was an independent factor influencing the survival of glioma patients (RR=2.193, 95%CI: 1.507-3.192, P<0.01). In the CGGA database, there were 325 genes that were positively correlated with CALU expression. The biological functions of those genes were mainly signal transduction, cell adhesion and cellular metabolism, and were mainly involved in endoplasmic reticulum protein processing, adhesion and cancer pathways. Conclusion CALU is significantly related to the malignancy of brain glioma and may serve as an independent prognostic factor in high grade glioma patients, which thus provides a potential therapeutic target in the future research. Key words: Glioma; Gene expression; Prognosis; Calumenin