Down-regulation of long noncoding RNA PGM5-AS1 correlates with tumor progression and predicts poor prognosis in clear cell renal cell carcinoma

OBJECTIVE Growing studies have shown that long non-coding RNAs (lncRNAs) have critical regulatory roles in tumorigenesis. Recently, a newly identified lncRNA, Homo sapiens PGM5 antisense RNA 1 (PGM5-AS1), was found to be dysregulated in several tumors. However, its roles in clear cell renal cell carcinoma (ccRCC) have not been investigated. The aim of the present study was to clarify the clinical significance of PGM5-AS1 in ccRCC patients. PATIENTS AND METHODS The PGM5-AS1 expression levels were evaluated in 182 primary ccRCC patients using quantitative real-time PCR assays. The associations between expression of PGM5-AS1, clinicopathological parameters, and prognosis of ccRCC were examined using Chi-square test, Kaplan-Meier assays, and multivariate assays. RESULTS The expressions of PGM5-AS1 in cancer specimens were lower than those in matched non-tumor specimens from the ccRCC patient (p<0.05). Downregulation of PGM5-AS1 was closely associated with more advanced clinical features, including lymph nodes metastasis (p=0.007) and distant metastasis (p=0.037). A clinical study revealed that ccRCC patients with lower PGM5-AS1 expressions had substantially shorter overall survival (OS) and disease-free survival (DFS) than patients with higher PGM5-AS1 expressions. Further multivariate assays demonstrated that PGM5-AS1 was identified as an independent prognostic factor for patients with ccRCC. CONCLUSIONS Down-regulation of PGM5-AS1 in ccRCC tissues had a strong association with unfavorable outcomes and PGM5-AS1 might be a potential tumor suppressor.