Ornithine aminotransferase supports polyamine synthesis in pancreatic cancer.
Min-Sik LeeCourtney DennisInsia NaqviLucas DaileyAlireza LorzadehGeorge YeTamara ZaytouniAshley AdlerDaniel S HitchcockLin LinMegan T HoffmanAladdin M BhuiyanJaimie L BarthMiranda E MachacekMari A Mino-KenudsonStephanie K DouganUnmesh JadhavAndrew T ChanNada Y KalaanyPublished in: Nature (2023)
There is a need to develop effective therapies for pancreatic ductal adenocarcinoma (PDA), a highly lethal malignancy with increasing incidence 1 and poor prognosis 2 . Although targeting tumour metabolism has been the focus of intense investigation for more than a decade, tumour metabolic plasticity and high risk of toxicity have limited this anticancer strategy 3,4 . Here we use genetic and pharmacological approaches in human and mouse in vitro and in vivo models to show that PDA has a distinct dependence on de novo ornithine synthesis from glutamine. We find that this process, which is mediated through ornithine aminotransferase (OAT), supports polyamine synthesis and is required for tumour growth. This directional OAT activity is usually largely restricted to infancy and contrasts with the reliance of most adult normal tissues and other cancer types on arginine-derived ornithine for polyamine synthesis 5,6 . This dependency associates with arginine depletion in the PDA tumour microenvironment and is driven by mutant KRAS. Activated KRAS induces the expression of OAT and polyamine synthesis enzymes, leading to alterations in the transcriptome and open chromatin landscape in PDA tumour cells. The distinct dependence of PDA, but not normal tissue, on OAT-mediated de novo ornithine synthesis provides an attractive therapeutic window for treating patients with pancreatic cancer with minimal toxicity.
Keyphrases
- poor prognosis
- gene expression
- long non coding rna
- nitric oxide
- stem cells
- single cell
- genome wide
- endothelial cells
- squamous cell carcinoma
- dna methylation
- induced apoptosis
- risk factors
- papillary thyroid
- wild type
- transcription factor
- cell death
- cancer therapy
- physical activity
- induced pluripotent stem cells
- squamous cell