Breaking the mucin barrier: a new affinity chromatography-mass spectrometry approach to unveil potential cell markers and pathways altered in Pseudomyxoma peritonei

Background Pseudomyxoma peritonei (PMP) is a rare peritoneal mucinous carcinomatosis with unknown underlying molecular mechanisms. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is the only therapeutic option; however, despite its use, recurrence with a fatal outcome is common. The lack of molecular characterisation in PMP and other mucinous tumours is mainly due to the physicochemical properties of mucin. Results This manuscript describes the first protocol capable of breaking the mucin barrier and isolating proteins from mucinous tumours. Thus, we present here the first proteome analysed in PMP and identified a distinct mucin isoform profile in soft compared to hard mucin tissues as well as key biological processes/pathways altered in mucinous tumours. Importantly, this protocol also allowed us to identify MUC13 as a potential tumour cell marker in PMP. Conclusions In summary, our results demonstrate that this protein isolation protocol from mucin will have a high impact, allowing the oncology research community to more rapidly advance in the knowledge of PMP and mucinous neoplasms, as well as develop new and effective therapeutic strategies.