Jupe E R, Liu X T, Kiehlbauch J L, McClung J K, Dell'Orco R T
Noble Center for Biomedical Research, Oklahoma Medical Research Foundation, Oklahoma City 73104, USA.
Exp Cell Res. 1995 Jun;218(2):577-80. doi: 10.1006/excr.1995.1194.
Experiments were performed to determine whether prohibitin, an evolutionarily conserved gene with antiproliferative activity, has a role in cellular immortalization. A cell proliferation assay was used to examine one human cell line from each of four established immortal complementation groups, termed A, B, C, and D, and a normal human diploid fibroblast line. Only normal and Group B cells were inhibited from traversing the cell cycle after introduction of wild-type prohibitin transcript. All of the immortalized cells expressed elevated levels of prohibitin mRNA and protein. Prohibitin gene structural characterization using Southern and single-strand conformation polymorphism (SSCP) analyses distinguished two alleles. One is cleaved at a polymorphic intronic EcoRI site, exhibits an exon 6-associated SSCP, and is homozygous only in Group B cells. The other is not cleaved at the EcoRI site, has a different exon 6 SSCP pattern, and is homozygous in Groups A, C, and D. In contrast, normal cells are heterozygous for the alleles. These results suggest that prohibitin may play a role as a tumor suppressor in the immortalization of Group B cells.
