ATRX protein is a potential prognostic marker in clear cell renal cell carcinoma

Objective: Cancer cells activate either telomerase or alternative lengthening of telomeres (ALT) to maintain telomere length and achieve immortalization. Alpha thalassemia/mental retardation X-linked (ATRX) is involved in chromatin remodeling. Mutations in ATRX genes are associated with the loss of nuclear expression and correlated with the ALT phenotype. ATRX expression has been evaluated in various cancers, especially sarcoma and neuroendocrine tumors, and its clinical significance has been shown to be diverse, depending on the tumor types. The role and prognostic value of ATRX expression in clear cell renal cell carcinoma (CCRCC) have not been elucidated. Methods: We investigated the messenger RNA (mRNA) expression levels of ATRX using the gene expression profiling interactive analysis (GEPIA) database and evaluated the expression of ATRX using immunohistochemical (IHC) staining in 302 CCRCC cases. Results: Loss of ATRX expression was significantly associated with larger tumor size, higher nuclear grade (NG), lymphovascular invasion (LVI), pathologic T (pT) stage, recurrence/metastasis, and stage. Although ATRX was not an independent prognostic factor, patients with loss of ATRX expression showed poor survival. Conclusion: Our findings suggest that loss of ATRX expression could be a potential biomarker for predicting aggressive tumor behavior and poor clinical outcomes in CCRCC.