Organoids at the PUB: The Porcine Urinary Bladder Serves as a Pancreatic Niche for Advanced Cancer Modeling

Abstract

Despite intensive research and progress in personalized medicine, pancreatic ductal adenocarcinoma remains one of the deadliest cancer entities. Pancreatic duct‐like organoids (PDLOs) derived from human pluripotent stem cells (PSCs) or pancreatic cancer patient‐derived organoids (PDOs) provide unique tools to study early and late stage dysplasia and to foster personalized medicine. However, such advanced systems are neither rapidly nor easily accessible and require an in vivo niche to study tumor formation and interaction with the stroma. Here, the establishment of the porcine urinary bladder (PUB) is revealed as an advanced organ culture model for shaping an ex vivo pancreatic niche. This model allows pancreatic progenitor cells to enter the ductal and endocrine lineages, while PDLOs further mature into duct‐like tissue. Accordingly, the PUB offers an ex vivo platform for earliest pancreatic dysplasia and cancer if PDLOs feature KRASG12D mutations. Finally, it is demonstrated that PDOs‐on‐PUB i) resemble primary pancreatic cancer, ii) preserve cancer subtypes, iii) enable the study of niche epithelial crosstalk by spiking in pancreatic stellate and immune cells into the grafts, and finally iv) allow drug testing. In summary, the PUB advances the existing pancreatic cancer models by adding feasibility, complexity, and customization at low cost and high flexibility.

TBX3 is dynamically expressed in pancreatic organogenesis and fine-tunes regeneration

“…Thus, we employed an inducible knockdown of TBX3 by an shRNA in a previously reported iPSC line [ 12 ] during in vitro pancreatic progenitor differentiation [ 58 – 61 ]. We assessed trilineage potential (generation of acinar, ductal, and endocrine cells) in a recently described porcine urinary bladder (PUB) organ culture model for the maturation of pancreatic progenitor cells [ 62 , 63 ] (Additional file 1 : Fig. S5a).…”

“…The medium was changed on a daily basis. After the differentiation of pancreatic progenitor cells, organ culture of porcine urinary bladders was performed as described recently [ 62 , 63 ]. Briefly, porcine urinary bladders (PUB) were cleaned, de-epithelialized, and sterilized with 0.1% peroxy-acetic acid.…”

“…The medium of PUBs was changed once a week, and doxycycline was added twice a week freshly. After 2 weeks, PUBs were fixed in 3.7% formaldehyde and processed for histology as described recently [ 62 , 63 ].…”

“…All histological experiments on FFPE tissue were performed as previously described [ 20 , 59 , 62 ]) following standard procedures. Four-micrometer-thin sections were rehydrated.…”

KRAS mutation: The booster of pancreatic ductal adenocarcinoma transformation and progression

“…However, some studies have highlighted that low levels of ROS are more able to promote the progression of pancreatic cancer with KRAS G12D mutation (Melzer et al, 2022). Some studies have in turn emphasized that reducing ROS production delays the progression of pancreatic cancer with KRAS G12D mutation (Eser et al, 2014;Bear et al, 2020;Ohara et al, 2022).…”