Foxo3 circular RNA retards cell cycle progression via forming ternary complexes with p21 and CDK2

Area of Science:

• Molecular Biology
• Genomics
• Cell Biology

Background:

• Non-coding RNAs (ncRNAs) are abundant transcripts with diverse functions.
• Circular RNAs (circRNAs) are a class of ncRNAs with largely unknown roles.
• circ-Foxo3 is a specific circRNA implicated in cellular processes.

Purpose of the Study:

• To investigate the function of circ-Foxo3 in cell cycle regulation.
• To elucidate the molecular mechanism by which circ-Foxo3 affects cell proliferation.
• To determine the interaction partners of circ-Foxo3 in the context of cell cycle control.

Main Methods:

• Quantitative analysis of circ-Foxo3 expression in different cell types.
• RNA interference (RNAi) to silence endogenous circ-Foxo3.
• Overexpression studies to assess the impact of ectopic circ-Foxo3.
• Co-immunoprecipitation assays to identify protein binding partners.

Main Results:

• circ-Foxo3 expression is higher in non-cancer cells and correlates with cell cycle progression.
• Silencing circ-Foxo3 enhances cell proliferation.
• Ectopic expression of circ-Foxo3 inhibits cell cycle progression.
• circ-Foxo3 forms a ternary complex with CDK2 and p21, inhibiting CDK2 activity.

Conclusions:

• circ-Foxo3 acts as a crucial regulator of cell cycle progression.
• The circ-Foxo3-p21-CDK2 complex formation is a key mechanism for cell cycle arrest.
• circ-Foxo3 plays a role in maintaining normal cell proliferation by inhibiting cell cycle entry.