Related Experiment Video
Updated: Jun 15, 2025
Induction of Invasive Transitional Cell Bladder Carcinoma in Immune Intact Human MUC1 Transgenic Mice: A Model for Immunotherapy Development
Published on: October 30, 2013
CircRNA ATF6 suppresses bladder cancer cell proliferation and migration via miR-146a-5p/FLNA axis
Bing Lu1, Yongqiang Zhou2, Zheng Ma2
1Department of Urology, Dushu Lake Hospital Affiliated to Soochow University, Suzhou, Jiangsu 215000, China.
Background:
Bladder cancer (BCa) is the most common malignancy with increasing morbidity and mortality. Circular RNA (circRNA) ATF6 level was downregulated in BCa after GSE92675 CircRNA microarray dataset was analyzed using GEO2R. However, its function and mechanism in BCa remain largely unknown.
Methods:
GEO2R and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were used to measure levels of circRNA ATF6, microRNA-146a-5p (miR-146a-5p), and filamin A (FLNA). CircRNA ATF6 stability was assessed by actinomycin D and RNase R assays, while circRNA ATF6 cellular localization was examined by FISH experiments in T24 cells. Cell counting kit-8 (CCK-8), colony formation, wound-healing, and transwell assays were used to study circRNA ATF6's function in growth, motility, and invasion. By examining luciferase, starBase, RNA pull-down, and RNA immunoprecipitation (RIP) experiments, we anticipated and confirmed miR-146a-5p interactions with circRNA ATF6, as well as miR-146a-5p interactions with FLNA. On tumor-bearing mice, in vivo experiments were conducted.
Results:
MiR-146a-5p expression in Bca was elevated, while circRNA ATF6 and FLNA were downregulated. CircRNA ATF6 showed better stability in BCa cells, with its expression primarily in the cytoplasm. Upregulating circRNA ATF6 lowered BCa cell viability, colony numbers, and invasion numbers, but broadened their migratory pattern. MiR-146a-5p was directly sponged up by circRNA ATF6, which also detrimentally affected miR-146a-5p levels in BCa. MiR-146a-5p reduced BCa FLNA expression by targeting FLNA. FLNA silencing abolished circRNA ATF6's mitigating function in BCa cell proliferation, motility, and invasion. In vivo, overexpression of circRNA ATF6 significantly reduced tumor volume and weight.
Conclusion:
CircRNA ATF6 suppresses BCa cell growth, migration and invasion through the miR-146a-5p/FLNA axis.
Insights
Circular RNA ATF6 (circRNA ATF6) suppresses bladder cancer (BCa) progression by inhibiting cell growth, migration, and invasion. This mechanism involves the microRNA-146a-5p (miR-146a-5p) and filamin A (FLNA) pathway, offering potential therapeutic targets for BCa.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Bladder cancer (BCa) presents a significant global health challenge with increasing incidence and mortality.
- Circular RNA ATF6 (circRNA ATF6) is downregulated in BCa, and its functional role remains largely unelucidated.
- Understanding the molecular mechanisms underlying BCa progression is crucial for developing effective therapeutic strategies.
Purpose of the Study:
- To investigate the function and molecular mechanism of circRNA ATF6 in bladder cancer.
- To explore the potential interaction between circRNA ATF6, microRNA-146a-5p (miR-146a-5p), and filamin A (FLNA) in BCa.
- To evaluate the therapeutic potential of circRNA ATF6 in preclinical models of BCa.
Main Methods:
- Differential expression analysis of circRNA ATF6, miR-146a-5p, and FLNA using GEO2R and RT-qPCR.
- Assessment of circRNA ATF6 stability and cellular localization via actinomycin D, RNase R, and FISH assays.
- Functional assays including CCK-8, colony formation, wound-healing, and Transwell assays to evaluate BCa cell behavior.
- Luciferase reporter assays, RNA pull-down, and RIP experiments to confirm molecular interactions.
- In vivo studies using tumor-bearing mice to assess the effect of circRNA ATF6 on tumor growth.
Main Results:
- CircRNA ATF6 and FLNA were downregulated, while miR-146a-5p was upregulated in BCa tissues.
- CircRNA ATF6 demonstrated stability and cytoplasmic localization, suppressing BCa cell viability, colony formation, and invasion.
- CircRNA ATF6 directly sponged miR-146a-5p, and miR-146a-5p targeted FLNA, inhibiting BCa progression.
- Overexpression of circRNA ATF6 significantly reduced tumor growth and weight in vivo.
Conclusions:
- CircRNA ATF6 acts as a tumor suppressor in bladder cancer by inhibiting cell proliferation, migration, and invasion.
- The circRNA ATF6/miR-146a-5p/FLNA axis represents a novel regulatory pathway in BCa pathogenesis.
- CircRNA ATF6 holds potential as a therapeutic target for bladder cancer treatment.
