PML hyposumoylation is responsible for the resistance of pancreatic cancer

Abstract

The dismal prognosis of pancreatic ductal adenocarcinoma (PDAC) is mainly due to its rapidly acquired resistance to all conventional treatments. Despite drug‐specific mechanisms of resistance, none explains how these cells resist the stress induced by any kind of anticancer treatment. Activation of stress‐response pathways relies on the post‐translational modifications (PTMs) of involved proteins. Among all PTMs, those mediated by the ubiquitin family of proteins play a central role. Our aim was to identify alterations of ubiquitination, neddylation, and sumoylation associated with the multiresistant phenotype and demonstrate their implications in the survival of PDAC cells undergoing treatment. This approach pointed at an alteration of promyelocytic leukemia (PML) protein sumoylation associated with both gemcitabine and oxaliplatin resistance. We could show that this alteration of PML sumoylation is part of a general mechanism of drug resistance, which in addition involves the abnormal activation of NF‐αB and cAMP response element binding pathways. Importantly, using patient‐derived tumors and cell lines, we identified a correlation between the levels of PML expression and sumoylation and the sensitivity of tumors to anticancer treatments.—Swayden, M., Alzeeb, G., Masoud, R., Berthois, Y., Audebert, S., Camoin, L., Hannouche, L., Vachon, H., Gayet, O., Bigonnet, M., Roques, J., Silvy, F., Carrier, A., Dusetti, N., Iovanna, J. L., Soubeyran, P. PML hyposumoylation is responsible for the resistance of pancreatic cancer. FASEB J. 33, 12447–12463 (2019). http://www.fasebj.org

ZZW-115–dependent inhibition of NUPR1 nuclear translocation sensitizes cancer cells to genotoxic agents

“…Then, we studied whether inactivation of NUPR1 by a siRNA interference approach shows similar consequences as ZZW-115 treatment on the TP53 SUMOylation. To do this, we treated the MiaPaCa-2, stably transfected with SUMO1 ( 21 ), with siRNA against NUPR1 and then treated them with 5-FU. SUMOylation of TP53 was quantified by PLA using mouse anti-Flag and rabbit anti-TP53.…”

“…MiaPaCa-2 cells were seeded on coverslips and transfected with 2 μg of plasmid DNA (Nupr1-Flag or importin-α3-Flag) using Lipofectamine 3000 Transfection Reagent (Thermo Fisher Scientific). MiaPaCa-2-6HF-SUMO1 cells, previously described (21), were used to measure the SUMOylation of TP53. At the end of the experiment, cells were washed in PBS, fixed, and permeabilized before immunostaining with Duolink In Situ (MilliporeSigma) following the manufacturer's protocol.…”

The SUMO pathway in pancreatic cancer: insights and inhibition

“…Promyelocytic leukaemia protein (PML) nuclear bodies are known to be involved in the regulation of cellular processes that are relevant to tumour suppression, such as DNA repair and the DNA damage response (DDR). 24 The function of these nuclear organelles has been shown to be dependent on the appropriate SUMOylation of the major structural component PML, and hypoSUMOylation of PML in PDAC cells 25 was associated with increased activation of the NFκB pathway to mediate gemcitabine resistance and increased activation of the cAMP response element-binding pathway to mediate oxaliplatin resistance. 25 Importantly, a distinct heterogeneity of PML expression and PML SUMOylation was detected in patient-derived xenograft (PDX) models.…”

“…This observation was interpreted by the authors as indication for a decreased likelihood for responding to chemotherapy in the more aggressive, PML-score low population. 25 To directly test PML as an indicator of chemotherapy responsiveness, PDX-derived cell lines were investigated. Indeed, higher levels of secreted PML, determined by proteomic analysis of secretomes, were connected with increased drug sensitivity.…”

“…Indeed, higher levels of secreted PML, determined by proteomic analysis of secretomes, were connected with increased drug sensitivity. 25 Although PML containing extracellular vesicles was described, 26 the value of PML and its SUMOylation status in secretomes as a diagnostic marker for therapy responsiveness awaits further validation.…”