KEY TAKEAWAYS
- The study aimed to explore YAP1 knockdown’s effect on BCSCs, focusing on YTHDF3-mediated stabilization of SMAD7.
- Researchers noticed that silencing YAP1 in BCSCs impedes YTHDF3-mediated degradation of m6A-modified SMAD7, resulting in reduced cell stemness.
The previous study established the oncogenic role of Yes-associated protein 1 (YAP1) in bladder cancer (BLCA). Building on this, the current research focuses on the effects of YAP1 on bladder cancer stem cells (BCSCs) and explores the underlying mechanisms involved.
Dandan Qiu and the team aimed to assess the impact of YAP1 knockdown on BCSCs, particularly examining how it influences YTHDF3-mediated degradation of m6A-modified SMAD7 and its subsequent effect on cell stemness.
They performed an inclusive analysis involving BCSCs derived from human BLCA cells (UMUC3) treated with cisplatin, identified by CD133+ expression via flow cytometry. They utilized bioinformatics to analyze YAP1 interaction proteins and N6-methyladenosine (m6A) modifications on mothers against decapentaplegic homolog 7 (SMAD7).
BCSCs were transfected, and subsequent analyses of SMAD7 m6A levels, YTH domain-containing family proteins 3 (YTHDF3)-SMAD7 interactions, and YAP1/YTHDF3 expression were conducted using methylated RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), and quantitative reverse transcription PCR (qRT-PCR). The proliferation of BCSCs was assessed through 5-Bromo-2-deoxyuridine (BrdU) staining.
Migration, invasion, and tumor sphere formation of UMUC3/BCSCs were evaluated using Transwell assays and tumor sphere formation assays. Western blot assays were employed to measure expressions of YAP1, YTHDF3, SMAD7, transforming growth factor (TGF)-β1, and stemness markers in UMUC3/BCSCs.
The BCSCs showed a higher CD133+ ratio, increased expressions of stemness markers, YAP1, YTHDF3, and TGF-β1, along with reduced SMAD7 expression and enhanced invasion, migration, and tumor sphere formation capabilities were observed compared to UMUC3 cells. YAP1 knockdown led to a decrease in SMAD7 m6A levels and disrupted the YTHDF3-SMAD7 interaction in BCSCs.
Silencing YAP1 resulted in reduced cell growth, invasiveness, migration, and tumor sphere formation, alongside lower levels of stemness-associated proteins, YTHDF3, and TGF-β1, while increasing SMAD7 expression in BCSCs. However, these effects were counteracted by YTHDF3 overexpression.
The study concluded that silencing YAP1 in BCSCs impedes the YTHDF3-mediated degradation of m6A-modified SMAD7, leading to a reduction in cell stemness.
No funding information was given for this source.
Source: https://pubmed.ncbi.nlm.nih.gov/39054719/
Qiu D, Gao L, Yu X. (2024). “Knockdown of YAP1 Reduces YTHDF3 to Stabilize SMAD7 and thus Inhibit Bladder Cancer Stem Cell Stemness.” Discov Med. 2024;36(186):1486-1498. doi:10.24976/Discov.Med.202436186.138
