Ex vivo culture of tumor cells from N-methyl-N-nitrosourea-induced bladder cancer in rats: Development of organoids and an immortalized cell line

Urol Oncol. 2018 Apr;36(4):160.e23-160.e32. doi: 10.1016/j.urolonc.2017.11.024. Epub 2017 Dec 26.

Abstract

Objective: We ex vivo cultured primary tumor cells from N-methyl-N-nitrosourea (MNU)-induced bladder tumors in rats and established an immortalized cell line from them.

Materials and methods: Bladder tumors in rats were induced by instillation of MNU into the murine bladder. Primary tumor cells were prepared by the cancer-tissue originated spheroid method. An immortalized cell line was established by co-culture with fibroblasts. The cultured tumor cells were molecularly and functionally characterized by quantitative real-time polymerase chain reaction, Western blot, growth assay, and transwell migration assay.

Results: Primary tumor cells were successfully prepared as multicellular spheroids from MNU-induced bladder tumors. The differentiation marker expression patterns observed in the original tumors were largely retained in the spheroids. We succeeded in establishing a cell line from the spheroids and named it T-MNU-1. Although basal markers (CK14 and CK5) were enriched in T-MNU-1 compared to the spheroids, T-MNU-1 expressed both luminal and basal markers. T-MNU-1 was able to migrate through a transwell.

Conclusions: Tumor cells in MNU-induced bladder tumors were successfully cultured ex vivo as organoids, and an immortalized cell line was also established from them. The ex vivo models offer a platform that enables analysis of intrinsic characteristics of tumor cells excluding influence of microenvironment in MNU-induced bladder tumors.

Keywords: Bladder cancer; Cell line; N-methyl-N-nitrosourea; Organoid; Primary culture; Spheroid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Transitional Cell / chemically induced
  • Carcinoma, Transitional Cell / pathology*
  • Cell Differentiation
  • Cell Line, Tumor
  • Coculture Techniques
  • Female
  • Fibroblasts
  • Humans
  • Methylnitrosourea / toxicity
  • Mice
  • Organoids / pathology*
  • Primary Cell Culture
  • Rats
  • Rats, Inbred F344
  • Spheroids, Cellular
  • Urinary Bladder / cytology*
  • Urinary Bladder Neoplasms / chemically induced
  • Urinary Bladder Neoplasms / pathology*

Substances

  • Methylnitrosourea