Expression of circular RNA circASXL1 correlates with TNM classification and predicts overall survival in bladder cancer

Gang Tang; Wanqin Xie; Chuan Qin; Yunpeng Zhen; Yinlei Wang; Feiran Chen; Zhiyong Du; Zhouliang Wu; Bo Zhang; Zhonghua Shen; Dawei Tian; Hailong Hu

Expression of circular RNA circASXL1 correlates with TNM classification and predicts overall survival in bladder cancer

Int J Clin Exp Pathol. 2017 Aug 1;10(8):8495-8502. eCollection 2017.

Authors

Gang Tang^{1

2}, Wanqin Xie³, Chuan Qin^{1

2}, Yunpeng Zhen^{1

2}, Yinlei Wang^{1

2}, Feiran Chen^{1

2}, Zhiyong Du^{1

2}, Zhouliang Wu^{1

2}, Bo Zhang^{1

2}, Zhonghua Shen^{1

2}, Dawei Tian^{1

2}, Hailong Hu^{1

2}

Affiliations

¹ Department of Urology, The Second Hospital of Tianjin Medical University Tianjin, China.
² Tianjin Key Laboratory of Urology, Tianjin Institute of Urology, The Second Hospital of Tianjin Medical University Tianjin, China.
³ Key Laboratory of Genetics and Birth Health of Hunan Province, The Family Planning Research Institute of Hunan Province Changsha, Hunan, China.

PMID: 31966702
PMCID: PMC6965445

Abstract

Circular RNAs (circRNAs) as a family of non-coding RNAs are increasingly recognized regarding their biogenesis, regulatory roles in gene expression and clinic significance in developmental diseases and cancers. In this study, we aim to identify circRNAs that may be associated with clinicopathological characteristics of patients with bladder cancer. The circRNAs databases CircBase and circ2 Traits were used to seek circRNAs reported to bladder cancer. The expression levels of the circRNA of interest in paired samples of tumor tissue and adjacent normal mucosa from 61 patients with bladder cancer were detected by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and statistically analyzed. Database search shows that circASXL1 (circBase ID: hsa_circ_0001136) transcribed from the ASXL1 gene locus is among the circRNAs with altered expressions in bladder cancer. Results showed that the expression level of circASXL1 was significantly higher in bladder cancer tissues compared to that in adjacent noncancerous tissues (P<0.001). To be noticed, chi-square tests support that the expression of circASXL1 significantly correlates with tumor grade (P=0.025), tumor stage (P=0.019), lymph node invasion (P=0.011) and distant metastasis (P=0.032). The area under ROC curve (AUC) is 0.770 for circASXL1 in predicting tumor invasion (T2-T4 tumors). Kaplan-Meier survival analysis indicates that tumors of high circASXL1 expression are associated with shorter overall survival compared to tumors of low circASXL1 expression. Further, multivariate analysis reveals that circASXL1 is an independent prognostic factor for overall survival for patients with bladder cancer. Expression of circASXL1 in bladder tumor correlates with TNM classification and may independently predict overall survival for patients with bladder cancer.

Keywords: Circular RNA; biomarker; bladder cancer; circASXL1.