Expression analysis of the PMP22 gene in glioma and osteogenic sarcoma cell lines

Previously me reported the amplification of the peripheral myelin protein 2 2 (PMP22) gene in cell lines of human osteogenic and glioma tumors. PMP22 n ormally is expressed at high levels in Schwann cells of the peripheral nerv ous system and is suggested to function as a structural protein of the myel in sheath. One of the most common inherited peripheral neuropathies, Charco t-Marie-Tooth Type 1A (CMT1A), is associated with a duplication of a 1.5-Mb DNA region on chromosome 17p11.2-p12 containing PMP22. On the other hand, PMP22 is identical to gas3, whose expression is induced in growth-arresting NIH3T3-fibroblasts and is thought to play a role in cell proliferation. Th e precise role of gas3/PMP22 remains to be determined, Here we show that in the tumor cell lines RH30 and SF763 the amplified region including PMP22 c omprises the whole 1.5-Mb CMT1A region. We could prove expression of PMP22 by reverse transcriptase-polymerase chain reaction (RT-PCR) and discovered an unusual PMP22 transcript in these tumor cell lines. Western blot analyse s resulted in detection of a 22-kDa protein by the PMP22-specific antibody 558/2 and in exclusion of myelin protein zero (MPZ) expression in these cel l lines. (C) 1999 Wiley-Liss, Inc.