Lambda-like and V pre-B genes expression: an early B-lineage marker of human leukemias.
V pre-B and lambda-like genes are selectively expressed in human pre-B cells and encode polypeptide chains that associate in a mu-pseudolight chain complex that may regulate some crucial steps of early B-cell differentiation. We have followed by polymerase chain reaction and Northern blot analysis the expression of these "pre-B-specific" genes in correlation with the status (rearranged v germline) of Ig gene loci (H, kappa, lambda) in a panel of 32 leukemias pertaining mostly to the B lineage and including a number of ambiguously characterized samples. All cells that had rearranged the H locus only expressed V pre-B and lambda-like transcripts, in agreement with a pre-B status. In this group, some biphenotypic leukemias (mostly My/B) might, in fact, be already engaged in the B lineage. Rearrangement of V kappa or V lambda loci correlated with the disappearance of the pre-B gene products. In a pre-B acute lymphoblastic leukemia cell line that was induced to mature to the B-cell stage in culture upon kappa gene rearrangement, the mu-pseudolight chain complex was actually replaced by the classical mu-kappa molecule. Finally, V pre-B and lambda-like genes were found expressed in two leukemic cells that had retained all Ig loci in germline configuration. This finding raises the possibility of having an early pro-B progenitor in which V pre-B and lambda-like products associate with a H chain surrogate in a complex that would trigger an early event of B-cell differentiation such as the H locus rearrangements.
Schiff
C
C
Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, France.
Milili
M
M
Bossy
D
D
Tabilio
A
A
Falzetti
F
F
Gabert
J
J
Mannoni
P
P
Fougereau
M
M
D015703:Antigens, CD / Q000032:analysis; D001483:Base Sequence; D004273:DNA, Neoplasm / Q000302:isolation & purification; D015973:Gene Expression Regulation, Leukemic; D015322:Gene Rearrangement, B-Lymphocyte / Q000235:genetics*; D005803:Genes, Immunoglobulin / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D016130:Immunophenotyping; D015448:Leukemia, B-Cell / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D012334:RNA, Neoplasm / Q000302:isolation & purification; D014158:Transcription, Genetic
D015703:Antigens, CD; D004273:DNA, Neoplasm; D005819:Genetic Markers; D012334:RNA, Neoplasm