Multiple cystic sphere formation from PK-8 cells in three-dimensional culture

Yuuki Shichi; Fujiya Gomi; Yoshibumi Ueda; Keisuke Nonaka; Fumio Hasegawa; Yasuko Hasegawa; Nae Hinata; Hisashi Yoshimura; Masami Yamamoto; Kimimasa Takahashi; Tomio Arai; Toshiyuki Ishiwata

doi:10.1016/j.bbrep.2022.101339

Multiple cystic sphere formation from PK-8 cells in three-dimensional culture

Biochem Biophys Rep. 2022 Sep 7:32:101339. doi: 10.1016/j.bbrep.2022.101339. eCollection 2022 Dec.

Authors

Affiliations

¹ Division of Aging and Carcinogenesis, Research Team for Geriatric Pathology, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015, Japan.
² Department of Chemistry, School of Science, The University of Tokyo, Tokyo, 113-8654, Japan.
³ Department of Clinical Engineering School of Health Sciences, Tokyo University of Technology, Tokyo, 144-8535, Japan.
⁴ Laboratory of Physiological Pathology, Department of Applied Science, School of Veterinary Nursing and Technology, Nippon Veterinary and Life Science University, Tokyo, 180-8602, Japan.
⁵ Department of Veterinary Pathology, School of Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo, 180-8602, Japan.
⁶ Department of Pathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, 173-0015, Japan.

Abstract

Three-dimensional (3D) culture of cancer cells mimics the in vivo environment. Recently, we reported that pancreatic ductal adenocarcinoma (PDAC) cell lines with epithelial and mesenchymal features formed differently shaped spheres in 3D culture. However, only PK-8 cells, the epithelial PDAC cell line with the highest E-cadherin expression among the eight PDAC cell lines, formed multiple cystic spheres in 3D culture. Optical coherence tomography revealed interconnected cysts inside the spheres. A weak inter-cellular adhesion, individual cell degeneration, necrosis, and secretory granules in the cytoplasm were observed in the PK-8 spheres using electron microscopy. The expression of MUC1, MUC5AC, and amylase was increased in PK-8 cells in the 3D culture compared with that in 2D culture. These findings suggest that highly E-cadherin-expressing epithelial PK-8 cells form multiple cystic spheres, which may be promoted by enhanced mucin and amylase synthesis in 3D culture.

Keywords: Cyst; E-cadherin; PK-8; Pancreatic ductal adenocarcinoma/PDAC; Sphere; Three-dimensional culture.