The p16/Cdkn2a/Ink4a gene is frequently deleted in nitrosourea-induced rat glial tumors.
The present study investigates nitrosourea-induced rat (Rattus norvegicus) glioma cell lines for the functional status of the p16/Cdkn2a/Ink4a gene, which encodes the p16 cdk4 inhibitor and the alternative reading frame protein, p19ARF. We detected homozygous deletions of the p16/Cdkn2a/Ink4a gene locus in 4 of 5 glioma cell lines (C6, F98, RG2, and RGL.3), but not in the 9L gliosarcoma cell line or in a rat primary fibroblast cell line. RT-PCR demonstrated expression of the p16 and p19ARF mRNAs only in 9L cells and in rat fibroblasts. Comparative genomic in situ hybridization showed that the copy number of rat chromosome RNO5 was not altered in any of the glioma cell lines investigated, indicating that the deletions result from a discrete loss in the region of the p16/Cdkn2a/Ink4a locus. This is the first report of p16/Cdkn2a/Ink4a deletions present in nitrosourea-induced rat glioma cell lines. Since this genetic alteration is also commonly observed in human malignant glial tumors, our results validate the use of chemically induced rat glioma cell lines as an experimental model in the development of gene therapy strategies.
Schlegel
J
J
Molecular Neuropathology Laboratory, Department of Neuropathology, University Medical Center, Marburg, Germany. juergen.schlegel@lrz.tu-muenchen.de
Piontek
G
G
Kersting
M
M
Schuermann
M
M
Kappler
R
R
Scherthan
H
H
Weghorst
C
C
Buzard
G
G
Mennel
H
H
D000818:Animals; D002455:Cell Division; D002875:Chromosomes / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D005347:Fibroblasts / Q000473:pathology; D017353:Gene Deletion; D019942:Genes, p16 / Q000235:genetics*; D005910:Glioma / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D006720:Homozygote; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D009423:Nervous System Neoplasms / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D009607:Nitrosourea Compounds / Q000633:toxicity*; D012334:RNA, Neoplasm / Q000032:analysis*; D051381:Rats; D011916:Rats, Inbred F344 / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D009607:Nitrosourea Compounds; D012334:RNA, Neoplasm