[Analysis of cyclin dependent kinase inhibitors, p16INK4a and p15INK4b gene, in acute lymphoblastic leukemias].

We examined the abnormality of p16INK4a and p15INK4b genes in 14 cases of human acute lymphoblastic leukemias (L1; 8 sample from 6 cases, L2; 10 samples from 7 cases, L3; 1 sample from 1 case) using DNA from bone marrow cells. The frequency of homozygous deletion of p16INK4a was 21.4% (3/14) and that of p15INK4b was 7.1% (1/14) and both genes were deleted in 7.1% (1/14) according to Southern blot and PCR analysis. The deletion of p16INK4a and/or p15INK4b was detected in 50% (3/6) of L1, 28.6% (2/7) of L2. The frequency of deletion was 33.3% (3/9) of B cell origin, 66.7% (2/3) of T cell origin and 0% (0/2) of nonBnonT cell origin. By PCR-SSCP analysis on exon 1 and exon 2 of p16INK4a and p15INK4b genes, we detected one case of unusual migrated band in L1 B cell origin. The base substitution, C to G, located in intron 1 of p15INK4b, 9 base upstream of intron 1-exon 2 boundary, was determined by DNA sequencing analysis. Deletion of p16INK4a and/or p15INK4b gene may contribute to etiology of ALL.