Adipocytes WNT5a mediated dedifferentiation: a possible target in pancreatic cancer microenvironment

// Elena Zoico 1 , Elena Darra 1 , Vanni Rizzatti 1 , Simona Budui 1 , Guido Franceschetti 1 , Gloria Mazzali 1 , Andrea P. Rossi 1 , Francesco Fantin 1 , Marta Menegazzi 2 , Saverio Cinti 3 , Mauro Zamboni 1 1 Department of Medicine, Geriatrics Section, University of Verona, Verona, Italy 2 Department of Life and Reproduction Sciences, Biochemistry Section, University of Verona, Verona, Italy 3 Department of Experimental and Clinical Medicine, Center of Obesity-University of Ancona (Politecnica delle Marche), Ancona, Italy Correspondence to: Elena Zoico, e-mail: elena.zoico@univr.it Keywords: pancreatic cancer, adipocytes, tumor microenvironment, cell dedifferentiation, WNT5a Received: August 09, 2015      Accepted: February 06, 2016      Published: March 06, 2016 ABSTRACT A significant epidemiological association between obesity and pancreatic ductal adenocarcinoma (PDAC) has previously been described, as well as a correlation between the degree of pancreatic steatosis, PDAC risk and prognosis. The underlying mechanisms are still not completely known. After co-culture of 3T3-L1 adipocytes and MiaPaCa2 with an in vitro transwell system we observed the appearance of fibroblast-like cells, along with a decrease in number and size of remaining adipocytes. RT-PCR analyses of 3T3-L1 adipocytes in co-culture showed a decrease in gene expression of typical markers of mature adipocytes, in parallel with an increased expression of fibroblast-specific and reprogramming genes. We found an increased WNT5a gene and protein expression early in MiaPaCa2 cells in co-culture. Additionally, EMSA of c-Jun and AP1 in 3T3-L1 demonstrated an increased activation in adipocytes after co-culture. Treatment with WNT5a neutralizing antibody completely reverted the activation of c-Jun and AP1 observed in co-cultured adipocytes. Increasing doses of recombinant SFRP-5, a competitive inhibitor for WNT5a receptor, added to the co-culture medium, were able to block the dedifferentiation of adipocytes in co-culture. These data support a WNT5a-mediated dedifferentiation process with adipocytes reprogramming toward fibroblast-like cells that might profoundly influence cancer microenvironment.