Targeting PGE2 mediated senescent neuron improves tumour therapy

Abstract Background Recent studies have highlighted bidirectional signalling between tumours and neurons; however, the interactions between tumours and neurons in response to radio-/chemotherapy remain obscure, which hampers the tumour treatment. Methods Glioblastoma organoids (GBOs) and primary neuron coculture, targeted metabonomics, RNA pulldown, mass spectrum, co-immunoprecipitation, RNA-sequencing, transcript/protein validations and multi-electrode arrays were performed to analyse neuron-tumour interaction in response to therapy. In vivo validations were conducted in orthotopic mouse models. Diagnostic and prognostic values were evaluated in serum, tissue-microarray as well as TCGA. Results GBOs recruited and induced pro-tumour-survival senescent neurons upon radiation/chemotherapeutic treatment. Targeted metabonomics revealed that significantly increased tumour-derived prostaglandin E2 (PGE2) induced neuronal senescence phenotype. Screening of enzymes involved in PGE2 synthesis identified prostaglandin E synthase 3 (PTGES3) as the key enzyme responsible for PGE2 upregulation. Biochemical studies revealed that irradiation or chemotherapeutic drug-triggered asparagine endopeptidase (AEP) specifically cleaved eIF4A1 to produce teIF4A1-C, which dissociated from DDX6 and recruited eIF4A3 and PABPN1 to promote the mRNA stability of PTGES3. Elevated PGE2 reciprocally enhanced AEP expression. Inhibiting PGE2 or AEP reduced neuronal senescence and delayed tumour progression. Strikingly, single-cell analysis further showed that expressions of AEP/PTGES3/EIF4A1 in tumour cells were consistent with senescent neuronal CDKN1A in high-neuronal-connectivity glioblastoma. The serum PGE2 concentration was elevated after radiation and higher in resistant glioblastoma patients. High expression of PTGES3 was associated with a poor prognosis. Conclusions Our study revealed that the AEP/PGE2 feedback loop modulates tumour-induced neuronal senescence upon radio-/chemotherapy and highlight the therapeutic value to improve tumour therapy.