Molecular analysis of 1p32 genetic involvement in pediatric T-cell non- Hodgkin's lymphoma

Background and Objective. T-cell acute lymphoblastic leukemia (T-ALL) and lymphoblastic T-cell non-Hodgkin's lymphoma (T-NHL) are closely related disorders, and distinguishing between the two may be difficult. Cytogenetic investigations of large NHL series reported different recurring chromosomal alterations. Among these, aberrations of chromosome 1p seem to be associated with T-cell differentiation, the region most frequently involved in breakpoints being band 1p32-36. Deletions and translocations involving the same chromosomal region are frequently observed in T-ALL, in which one of the most common genetic changes is the breakage of the TAL1 gene, mapped to the 1p32 chromosomal region. The objective of this study was to assess the possibility of TAL1 involvement also in T-NHL. Design and Methods. A series of 17 pediatric T-NHL patients was molecularly characterized by microsatellite markers analysis and by TAL1 gene microdeletions. Results. TAL1 gene rearrangement was found in one case, while loss of heterozygosity (LOH) and microsatellite instability (MI) was identified in another case. Interpretation and Conclusions. Overall our findings indicate that, differently from T-ALL, neither TAL1 gene involvement nor LOH or MI at 1p32 appear particularly relevant in the oncogenic process of T-NHL transformation.