TRMP, a p53-inducible long noncoding RNA, regulates G1/S cell cycle progression by modulating IRES-dependent p27...

Area of Science:

• Molecular Biology
• Cancer Research
• Genetics

Background:

• The tumor suppressor p53 is crucial for cancer prevention.
• Long noncoding RNAs (lncRNAs) are increasingly recognized regulators of cellular pathways, including the p53 pathway.
• The precise mechanisms by which lncRNAs modulate p53 activity require further investigation.

Purpose of the Study:

• To identify and characterize novel p53-inducible lncRNAs.
• To elucidate the functional role of the identified lncRNA, TRMP, in the context of p53 activity and cancer.
• To explore the molecular mechanisms underlying TRMP's function.

Main Methods:

• Identification of p53-inducible lncRNAs.
• Functional knockdown experiments of TRMP in cancer cells.
• Analysis of cell proliferation and cell cycle progression (G1 arrest).
• Investigation of protein-RNA interactions using techniques like RNA immunoprecipitation.
• Assessment of TRMP's effect on p27 translation and polypyrimidine tract-binding protein 1 (PTBP1) binding.
• Evaluation of tumor xenograft growth in vivo.

Main Results:

• A novel p53-inducible lncRNA, termed TRMP (TP53-regulated modulator of p27), was identified.
• TRMP exhibits a pro-survival function, where its knockdown leads to inhibited cell proliferation and G1 cell cycle arrest.
• TRMP suppresses the internal ribosomal entry site (IRES)-dependent translation of p27 by competing with PTBP1 for p27 mRNA binding.
• TRMP regulates cell proliferation, G1/S cell cycle transition, and tumor growth through p27 inhibition.

Conclusions:

• lncRNAs represent a new regulatory layer for fine-tuning the p53 response.
• TRMP is identified as a significant downstream effector of p53, influencing cell cycle control and tumor progression.
• TRMP's mechanism involves the modulation of p27 translation, highlighting a novel lncRNA-mediated regulatory axis in cancer.