3D-spheroids : what can they tell us about pancreatic ductal adenocarcinoma cell phenotype?

We aimed at analyzing the effect of the 3D-arrangement on the expression of some genes and proteins which play a key role in pancreatic adenocarcinoma (PDAC) progression in HPAF-II, HPAC and PL45 PDAC cells cultured in either 2D-monolayers or 3D-spheroids. Cytokeratins 7, 8, 18, 19 were differently expressed in 3D-spheroids compared to 2D-monolayers. Syndecan 1 was upregulated in HPAF-II and PL45 3D-spheroids, and downregulated in HPAC. Heparanase mRNA levels were almost unchanged in HPAF-II, and increased in HPAC and PL45 3D-spheroids. Hyaluronan synthase (HAS) 2 and 3 mRNA increased in all 3D-spheroids compared to 2D-monolayers. CD44 and CD44s were expressed to a lower extent in HPAF-II and HPAC 3D-spheroids. By contrast, the CD44s/v3 and the CD44s/v6 ratio increased in HPAC and PL45 3D-spheroids, compared to 2D-monolayers. The expression of MMP-7 was strongly upregulated in 3D-spheroids. STAT3 was similarly expressed 3D-spheroids or 2D-monolayers, while pSTAT3 was almost undetectable in 2D-monolayers and strongly upregulated in 3D-spheroids. These results suggest that 3D-spheroids represent a cell culture model that allows the characterization of PDAC cell phenotype, adding new information that contributes to a better understanding of the biology and behavior of PDAC cells.