Gene Copy Number and Post-Transductional Mechanisms Regulate TRAP1 Expression in Human Colorectal Carcinomas.
Michele PietrafesaFrancesca MaddalenaLuciana PossidenteValentina CondelliPietro ZoppoliValeria Li BergolisMaria Grazia RodriquenzMichele AietaGiulia VitaFranca EspositoMatteo LandriscinaPublished in: International journal of molecular sciences (2019)
Tumor Necrosis Factor Receptor-Associated Protein 1 (TRAP1) is a heat shock protein 90 (HSP90) molecular chaperone overexpressed in 60-70% human colorectal carcinomas (CRCs) and the co-upregulation of TRAP1 and associated 6-related proteins identifies metastatic CRCs with poor prognosis. Since the molecular mechanisms responsible for TRAP1 regulation are still unknown, the significance of TRAP1 gene copy number (CN) and the role of post-transductional protein modifications were addressed. TRAP1 gene aneuploidy accounted for 34.5% of cases in a cohort of 58 human CRCs and TRAP1 CN correlated with its mRNA and protein expression, suggesting that transcriptional mechanisms are responsible for TRAP1 upregulation. Furthermore, the analysis of the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium/The Cancer Genome Atlas (CPTAC/TCGA) CRC database showed that TRAP1 polysomy significantly correlates with lymph node involvement. However, a subgroup of tumors showed TRAP1 protein levels independent from its CN. Of note, a direct correlation was observed between TRAP1 protein levels and the expression of S-nitrosoglutathione reductase (GSNOR), a denitrosylase involved in the regulation of protein S-nitrosylation. Furthermore, CRC cell lines exposed to hypoxia or dichloroacetate treatment showed the downregulation of TRAP1 upon GSNOR silencing and this resulted in increased TRAP1 mono/polyubiquitination. These data suggest that transcriptional and post-transductional mechanisms account for TRAP1 expression in human CRCs and GSNOR protects TRAP1 from S-nitrosylation and consequent proteasome degradation mostly in conditions of stress.
Keyphrases
- poor prognosis
- copy number
- endothelial cells
- heat shock protein
- genome wide
- lymph node
- mitochondrial dna
- binding protein
- small cell lung cancer
- long non coding rna
- squamous cell carcinoma
- rheumatoid arthritis
- emergency department
- dna methylation
- clinical trial
- heat shock
- signaling pathway
- gene expression
- induced pluripotent stem cells
- lymph node metastasis
- oxidative stress
- small molecule
- single cell
- amino acid
- single molecule
- pluripotent stem cells
- study protocol
- papillary thyroid
- protein protein
- genome wide analysis
- adverse drug