SLIRP maintains energy metabolism homeostasis in colorectal cancer by stabilizing mitochondrial-encoded mRNAs.

BACKGROUND

Colorectal cancer (CRC) is a highly vascularised tumour often characterised by elevated oxidative phosphorylation (OXPHOS) activity, positioning OXPHOS as a potential metabolic vulnerability for targeted therapy. SLIRP is an RNA-binding protein involved in the post-transcriptional regulation of mitochondrial gene expression. However, its specific function and underlying mechanism in CRC remain poorly understood.

METHODS

Clinical specimens and public databases were utilised to analyse both the subcellular localisation and expression of SLIRP in CRC. The functional role of SLIRP in CRC progression was assessed through cell growth, apoptosis, and metabolic analyses. Post-transcriptional regulation of mitochondrial-encoded mRNAs by SLIRP was investigated using RNA immunoprecipitation and mRNA stability assays.

RESULTS

SLIRP expression was significantly elevated in CRC tissues compared to adjacent normal tissues, and high SLIRP expression correlated with poor patient survival. SLIRP knockdown induced an ATP crisis, leading to suppressed tumour growth and increased apoptosis in CRC cells. Mechanistically, SLIRP globally binds to mitochondrial-encoded mRNAs and maintains their stability, functioning as a key post-transcriptional regulator of mitochondrial gene expression.

CONCLUSIONS

These findings uncover a critical role for SLIRP in maintaining OXPHOS activity in CRC and highlight its potential as both a prognostic biomarker and a therapeutic metabolic target.