BCL11A RNA expression in fetal, adult, and malignant tissues.

(A) Low-level expression of BCL11A RNA in a range of normal adult lymphoid tissues and fetal liver (Clontech Immune System MTN blot; 2 μg poly[A+] mRNA per lane; exposure time, 10 days). A low-level BCL11A transcript of 5.8 kb was seen, with highest levels present in normal lymph node. (B) High-level BCL11Aexpression was seen only in fetal brain (CNS d117) and in patient AS with t(2;14)(p13;q32.3). Predominant BCL11A transcripts of 5.8 kb, 3.5 kb, and 1.5 kb were seen in cases with t(2;14)(p13;q32.3) and in fetal brain. Otherwise, note low-level expression ofBCL11A in malignant B-cell lines (NAB-2 and Granta 452) and in human embryonic kidney fibroblast cell line, HEK-293. Loading control denoted by reprobing of same filters with glyceraldehyde phosphate dehydrogenase (GAPDH) probe shown below. (C) BCL11A mRNA accumulates in germinal center (GC) but not follicular mantle (FM) B cells. Antisense (i) and sense (ii)³⁵S-labeled riboprobes were hybridized to frozen sections of normal human tonsils, or a serial section (iii) was weakly stained with Giemsa to visualize the boundary of the high cellularity FM area. GC cells but not mantle cells exhibited BCL11Aexpression.