Wntless promotes bladder cancer growth and acts synergistically as a molecular target in combination with cisplatin
Sebastian C Schmid1, Anuja Sathe1, Ferdinand Guerth1
1Department of Urology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.
Purpose:
To analyze the contribution of Wnt signaling pathway to bladder cancer growth in order to identify suitable target molecules for therapy.
Material And Methods:
Expression of Wnt 2/4/7, LRP5/6, TCF1/2/4, LEF-1, and β-actin was detected by reverse transcription polymerase chain reaction in a panel of 9 and for Wntless (WLS) in 17 bladder cancer cell lines. Protein expression of WLS was detected in 6 cell lines. Wnt/β-catenin activity was analyzed using the TOPflash/FOPflash luciferase reporter assay. Expression level of β-catenin, WIF1, Dickkopf proteins (DKK), HSulf-2, sFRP4, and WLS was modulated by transfecting or infecting cells transiently or stably with respective shRNAs, siRNAs, or cDNAs. For protein detection, whole cell lysates were applied to sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by immunoblots. Effects on cell growth were determined by cell viability assays and BrdU/APC incorporation/staining. For 3-dimensional tumor growth, the chicken chorioallantoic membrane model was used. Tumor growth was characterized by weight.
Results:
Expression of molecular components and activation of the Wnt signaling pathway could be detected in all cell lines. Expression level of β-catenin, WIF1, DKK, WLS, and HSulf-2 influenced Wnt activity. Expression of WLS was confirmed in 17 cell lines by reverse transcription polymerase chain reaction and in 6 cell lines by immunoblotting. WLS positively regulates Wnt signaling, cell proliferation, and tumor growth in vitro and in vivo. These effects could be reversed by the expression of the Wnt antagonist WIF1 and DKK. Synergistic activity of cisplatin and WLS inactivation by genetic silencing could be observed on cell viability.
Conclusion:
The Wnt signaling pathway is ubiquitously activated in bladder cancer and regulates tumor growth. WLS might be a target protein for novel therapies in combination with established chemotherapy regimens.
Insights
The Wnt signaling pathway drives bladder cancer growth. Wntless (WLS) promotes tumor progression and may be a therapeutic target, especially when combined with chemotherapy.
Area of Science:
- Oncology
- Molecular Biology
- Cancer Research
Background:
- The Wnt signaling pathway plays a critical role in embryonic development and is implicated in various cancers.
- Aberrant activation of Wnt signaling is frequently observed in bladder cancer, contributing to tumor progression.
Purpose of the Study:
- To investigate the role of the Wnt signaling pathway in bladder cancer growth.
- To identify potential therapeutic targets within this pathway for bladder cancer treatment.
Main Methods:
- Gene expression analysis (RT-PCR) of Wnt pathway components in bladder cancer cell lines.
- Protein expression analysis (immunoblotting) of Wntless (WLS).
- Functional assays including luciferase reporter assays, cell viability assays, and in vivo tumor growth models (chicken chorioallantoic membrane).
- Genetic manipulation of Wnt pathway components using shRNAs, siRNAs, and cDNAs.
Main Results:
- Wnt signaling pathway components and activity were detected in all tested bladder cancer cell lines.
- Wntless (WLS) was identified as a key regulator of Wnt signaling, positively influencing cell proliferation and tumor growth.
- Inhibition of WLS, particularly in combination with cisplatin, demonstrated synergistic effects on cancer cell viability.
Conclusions:
- The Wnt signaling pathway is constitutively active in bladder cancer and essential for tumor growth.
- Wntless (WLS) represents a promising therapeutic target for bladder cancer, potentially enhancing the efficacy of existing chemotherapies.
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