Hepatic micropeptide modulates mitochondrial RNA processing machinery in hepatocellular carcinoma

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Micropeptides, products of noncanonical translation, are crucial in homeostasis and cancer.
• The role and mechanisms of micropeptides in hepatocellular carcinoma (HCC) are not well understood.

Purpose of the Study:

• To identify and characterize micropeptides in HCC.
• To elucidate the function of a specific micropeptide, MRPIP, in HCC progression.

Main Methods:

• Utilized an ultrafiltration tandem mass spectrometry assay for micropeptide identification in HCC samples.
• Investigated the molecular mechanisms of MRPIP, including its interaction with HSD17B10 and impact on mitochondrial RNA processing.
• Assessed the anti-cancer effects of MRPIP in vitro and in vivo.

Main Results:

• Identified numerous micropeptides in clinical HCC samples.
• Discovered that the lncRNA-derived micropeptide MRPIP attenuates HCC progression.
• MRPIP inhibits mitochondrial ribonuclease P (mtRNase P) complex assembly by interacting with HSD17B10, disrupting downstream processes and suppressing cancer growth.
• A 20-amino acid peptide derived from MRPIP demonstrated significant inhibition of HCC progression.

Conclusions:

• Uncovered a novel class of HCC-associated micropeptides.
• MRPIP and its derived peptide represent potential diagnostic markers and therapeutic agents for HCC.
• The study provides insights into micropeptide functions in cancer, particularly in mitochondrial regulation.