Activating transcription factor 3 inhibits endometrial carcinoma aggressiveness via JunB suppression

Area of Science:

• Oncology
• Molecular Biology
• Gene Regulation

Background:

• The role of Activating Transcription Factor 3 (ATF3) in cancer remains context-dependent and is not well-defined in endometrial carcinoma (EC).
• Preliminary western blot analysis in EC tissues revealed downregulation of ATF3 and upregulation of its interacting protein, JunB.

Purpose of the Study:

• To elucidate the function of ATF3 in endometrial carcinoma.
• To investigate the interaction between ATF3 and JunB and its downstream effects on EC cell behavior.

Main Methods:

• Western blot analysis to assess protein levels of ATF3 and JunB.
• Overexpression of ATF3 in EC cell lines.
• Cell proliferation, invasion, and apoptosis assays.
• Luciferase activity assay, chromatin precipitation, and DNA affinity assays to determine molecular interactions.
• Analysis of matrix metalloproteinases and tissue inhibitors of metalloproteinases expression.

Main Results:

• Overexpression of ATF3 in EC cells significantly inhibited cell proliferation and invasion while enhancing apoptosis.
• ATF3 overexpression led to suppressed JunB expression and altered the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases.
• ATF3's tumor-suppressive functions were mediated through binding with JunB and involvement in activator protein-1 signaling.
• The ATF3/JunB interaction was induced upon ATF3 overexpression and effectively mitigated EC cell proliferation, invasion, and metastasis.

Conclusions:

• The ATF3/JunB interaction plays a crucial role in suppressing endometrial carcinoma progression.
• Targeting the ATF3/JunB interaction presents a potential therapeutic strategy for endometrial carcinoma.