Establishment of immortalized murine mesothelial cells and a novel mesothelioma cell line.

Walter Blum,Marc De Perrot,Emanuela Felley-Bosco,Licun Wu,Janine Worthmüller-Rodriguez,Beat Schwaller,Bart Vrugt,László Pecze

doi:10.1007/s11626-015-9885-z

Abstract

Mesothelial cells are susceptible to asbestos fiber-induced cytotoxicity and on longer time scales to transformation; the resulting mesothelioma is a highly aggressive neoplasm that is considered as incurable at the present time Zucali et al. (Cancer Treatment Reviews 37:543–558, 2011). Only few murine cell culture models of immortalized mesothelial cells and mesothelioma cell lines exist to date. We generated SV40-immortalized cell lines derived from wild-type (WT) and neurofibromatosis 2 (merlin) heterozygote (Nf2+/−) mice, both on a commonly used genetic background, C57Bl/6J. All immortalized mesothelial clones consistently grow in DMEM supplemented with fetal bovine serum. Cells can be passaged for more than 40 times without any signs of morphological changes or a decrease in proliferation rate. The tumor suppressor gene NF2 is one of the most frequently mutated genes in human mesothelioma, but its detailed function is still unknown. Thus, these genotypically distinct cell lines likely relevant for malignant mesothelioma formation are expected to serve as useful in vitro models, in particular to compare with in vivo studies in mice of the same genotype. Furthermore, we generated a novel murine mesothelioma cell line RN5 originating from an Nf2+/− mouse subjected to repeated crocidolite exposure. RN5 cells are highly tumorigenic.

Highlights

Malignant mesothelioma (MM) is an aggressive form of cancer with an average survival time of about 1 yr; up to date, conventional therapies have proven to be rather unsuccessful (Rascoe et al 2012)
Mutations in the NF2 gene have been found in about 40% of human mesothelioma (Bianchi et al 1995; Sekido et al 1995; Deguen et al 1998), and the influence of Nf2 heterozygosity has been investigated in mice; Nf2 heterozygosity was shown to result in MM at high frequency (85%) within 1 yr after repetitive asbestos exposure (Altomare 2005)
The typical Bcobblestonelike^ morphology is conserved; all clones show a higher proliferation rate than their nonimmortalized primary counterparts. (b) Representative Incucyte growth curves of WT and Nf2+/− clones. (c) MTT signals obtained at 144 h postseeding using all cells and cell lines as in Fig. 1 and 2a. (d) MTT data grouped for three clones each of the genotypes WT and Nf2+/− in comparison to the primary mesothelial cells (*p

Summary

Introduction

Malignant mesothelioma (MM) is an aggressive form of cancer with an average survival time of about 1 yr; up to date, conventional therapies have proven to be rather unsuccessful (Rascoe et al 2012). For the investigation of the early steps of MM formation, immortalized cell lines derived from primary mesothelial cells are the tools of choice.

Results

Conclusion