Fig. 2.

Microenvironmental factors are essential for the growth and ductal formation of well differentiated PDO. A–D Effect of niche factors on the proliferation and differentiation of PDOs and PCCs. (left) Representative images of Grade1 (A), Grade2 (B), Grade3 (C) PDOs, and PCCs (D) cultured in serum medium or niche medium. Serum medium comprised basic medium supplemented with only 5% fetal bovine serum (FBS). Niche medium comprised basic medium supplemented with niche factors. + FBS, serum medium; + niche, niche medium. Inset, highly magnified views show morphological features. Scale bars, 100 µm. (right) Quantification of the growth rate of PDOs and PCCs (*P < 0.05; **P < 0.01; ***P < 0.001). E Summary of niche dependency in PDOs and PCCs. Niche dependency scores were calculated as the ratio of the proliferation fold change in niche medium to that in serum medium. F Immunofluorescence images for actin (red), E-cadherin (green), and DAPI (blue) in PDOs cultured in combined medium, which comprised the basic medium supplemented with both niche factors and 5% FBS