ANALYSIS OF P18(INK4C) IN ADULT T-CELL LEUKEMIA AND NON-HODGKINS-LYMPHOMA

p18(INK4C), a cyclin-dependent kinase inhibitor, is a homologue of p15 (INK4B) and p16(INK4A) which are frequently altered in a variety of ma lignancies. We searched for structural alterations of the p18(INK4C) g ene in 44 adult T-cell leukaemias (ATLs), 101 non-Hodgkin's lymphomas (NHLs), two polyclonal B-cell proliferations, seven ATL cell lines and seven leukaemia/lymphoma cell lines, by Southern blot and polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) anal yses. No genomic alterations of the p18(INK4C) gene were found in any of the samples. By RT-PCR, p18(INK4C) was not expressed in three of fi ve ATL cell lines, whereas it was expressed in all the non-ATL leukaem ia/lymphoma cell lines, Tax did not inhibit the expression of p18(INK4 C) in tax-expressing Jurkat cells.