Spatial transcriptomics identified mucin-specic O-glycosylation as a key pathway in pancreatic cancer development and a promising therapeutic target
Background: Intraductal papillary mucinous neoplasm (IPMN) are the most prevalent pancreatic cystic neoplasms which may progress to pancreatic ductal adenocarcinoma (PDAC), the most lethal solid malignancy. Therefore, patients suffering from this condition represent the ideal population where to address the efforts of identifying prevention or interception strategies. Here, we used spatial transcriptomics on IPMNs of different grade to identify mechanisms that are associated to the progression of those lesions toward invasive carcinomas.
Methods: We analysed 43 IPMNs grouped according to their dysplasia grade by digital spatial whole transcriptome analysis (GeoMX Human Whole Transcriptome Atlas). The high-resolution of the technology gave us the opportunity to define the genes activated along progression of IPMN to cancer, ruling out the background given by the non-neoplastic cells. The gene signature identified was validated for expression in an external validation cohort of IPMN patients and in TCGA dataset and as therapeutic target in in vitro 3D models and in in vivo syngeneic orthotopic model of PDAC.
Results: By spatial transcriptome profiling of IPMNs with different dysplasia grades, we identified more than 3000 genes differentially expressed between LGD-, HGD- IPMNs and during transformation into invasive carcinoma. One of the top differentially regulated gene signature, mucins-specific O-Glycosylation, was both validated in a cohort of patients (n=9) by immunofluorescence (IF) analysis and in TCGA dataset. Preclinical models of pancreatic cancer, including in vitro 3D and in vivo experiments confirmed the role of GCNT3 and mucins in protecting tumor cells from T-cells recognition.
Conclusions: We identified more than 3000 genes differentially expressed between LGD- and HGD- IPMNs and along the transformation from IPMN into invasive carcinoma. These results shed light on the role of mucin-specific O-glycosylation in the IPMN progression and in PDAC offering suitable markers for the early diagnosis. Moreover, we demonstrated in in vitro 3D models and in vivo experiment that GCNT3, the main regulator of mucins post-translational modification, is an actionable target in PDAC, paving the way for the development of novel strategies to target the protective mucin barrier to enhance PDAC chemotherapy efficacy.