Journal of Experimental & Clinical Cancer Research (Sep 2020)

Hsa_circ_0001944 promotes the growth and metastasis in bladder cancer cells by acting as a competitive endogenous RNA for miR-548

  • Mingming Jin,
  • Shengjie Lu,
  • Yue Wu,
  • Chen Yang,
  • Chunzi Shi,
  • Yanqiu Wang,
  • Gang Huang

DOI
https://doi.org/10.1186/s13046-020-01697-6
Journal volume & issue
Vol. 39, no. 1
pp. 1 – 12

Abstract

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Abstract Background Bladder cancer (BC) is a common genitourinary malignancy worldwide. Circular RNAs (circRNAs) participate in cancer development, including BC; thus, the roles of circRNAs in this process have attracted significant attention. Methods In this study, high-throughput sequencing was used to analyze circRNA expression profiles in BC tissues. We performed RT-qPCR to determine hsa_circ_0001944 expression in BC tissues. We used fluorescence in situ hybridization (FISH) to detect hsa_circ_0001944 expression and hsa_circ_0001944 subcellular localization in BC tissues. hsa_circ_0001944 expression in BC cells was selectively regulated. We employed CCK8, transwell, and wound healing assays to monitor cell proliferation, invasion, and migration, respectively. We employed the dual-luciferase reporter and RNA pulldown assays to verify the relationships among hsa_circ_0001944, miR-548, and PROK2. We examined the effects of hsa_circ_0001944 on BC cell metastasis and proliferation in vivo using a subcutaneous xenograft model and an intravenous tail injection model in nude mice. Results The results showed that hsa_circ_0001944 expression was significantly increased in BC samples. Furthermore, high hsa_circ_0001944 expression predicted unfavorable prognoses in BC. Functional assays validated that downregulating hsa_circ_0001944 decreased BC invasion and proliferation in vivo and in vitro. Further studies showed that hsa_circ_0001944 expression promoted BC progression via sponging miR-548 and enhancing PROK2 expression. Luciferase reporter experiments validated the interactions between hsa_circ_0001944, miR-548, and PROK2. This study also found that downregulating miR-548 or overexpressing PROK2 restored BC cell invasion and proliferation after silencing hsa_circ_0001944. Conclusions Taken together, we found that hsa_circ_0001944 is a tumor-promoting circRNA in BC that functions as a competing endogenous RNA to regulate PROK2 expression via sponging miR-548.

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