The WNT5A/ROR2 signaling pathway in pancreatic ductal adenocarcinoma (PDAC)

WNT5A/ROR2 signaling pathway has been involved in many human cancers. Its role in pancreatic ductal adenocarcinoma (PDAC) has not been clarified yet. The purpose of this study was to determine the prognostic value of WNT5A expression in conjunction with the ROR2 expression in the same PDAC human tissues.

We retrospectively analyzed by immunohistochemistry the WNT5A and ROR2 expression in117 paraffin-embedded PDAC specimens following surgical pancreatic resection. The prognostic value of WNT5A and ROR2 was assessed using Kaplan-Meier survival curves and multivariate Cox regression models.

High ROR2 expression was detected in 65.8% (77/117) of PDAC tumors, in 28.2% (33/117) in tumor-stroma, and in 71.1% (65/90) of normal pancreatic tissue. High WNT5A expression was found in 76.9% (90/117) of tumors, in 59.0% (69/117) of tumor-stroma, and in 83.0% (73/88) of normal pancreatic tissue. Spearman's correlation coefficiency demonstrated weak association between ROR2 and WNT5A expression in tumor (r=0.184; p=0.047), and no association in stroma (r=0.036; p=0.699). Multivariate analysis showed that regional lymph node invasion and differentiation were independent prognostic factors of survival, while ROR2- and WNT5A expression were not.

Variable expression patterns for ROR2 and WNT5A were demonstrated in PDAC and normal pancreatic tissues suggesting a role for WNT5A/ROR2 signalling pathway, not only in PDAC but also in the normal pancreatic tissue during inflammation. The lack of prognostic significance for ROR2 and WNT5A expression in our cohort, either alone or in subgroup analysis, underlines the complexity of their role in PDAC, which is highly dependent on the different molecular receptor-ligand tissue contexts.