Wilms tumor suppressor 1 (WT1) and early growth response 1 (EGR1) are regulators of STIM1 expression

Area of Science:

• Cell Biology
• Molecular Biology
• Oncology

Background:

• Store-operated calcium entry (SOCE) is a fundamental cellular process regulating calcium influx.
• Understanding SOCE regulation in cancer is critical for developing targeted therapies.
• Wilms tumor cells exhibit poorly understood calcium signaling pathways.

Purpose of the Study:

• To investigate the mechanisms of SOCE regulation in Wilms tumor cells.
• To identify molecular players involved in SOCE deficiency in this cancer type.
• To elucidate the role of WT1 and EGR1 in STIM1 expression and SOCE.

Main Methods:

• Primary Wilms tumor cell culture and functional assays for SOCE.
• Quantitative analysis of STIM1 and ORAI1 expression.
• Bioinformatic analysis of the STIM1 promoter using TESS.
• Gene manipulation (overexpression/knockdown) and chromatin immunoprecipitation (ChIP).
• In vivo studies using Egr1 knock-out animal models.

Main Results:

• Wilms tumor cells demonstrated undetectable SOCE.
• STIM1 expression was significantly reduced in Wilms tumor cells.
• WT1 and EGR1 were identified as key regulators of STIM1 transcription.
• WT1 and EGR1 directly bind to the STIM1 promoter, influencing STIM1 expression.
• Egr1 deficiency led to STIM1 loss in various tissues.

Conclusions:

• WT1 and EGR1 play a critical role in regulating STIM1 expression and SOCE.
• Dysregulation of WT1 and EGR1 may contribute to altered calcium signaling in Wilms tumors.
• These findings reveal novel mechanisms of calcium dysregulation in cancer cells.