[Transgenic mice expressing MTCP1: an animal model for T-cell prolymphocytic leukemia]

T-prolymphocytic leukemia (T-PLL) is a rare form of mature T-cell leukemia associated with chromosomal rearrangements of band 14q11, containing the gene TCRA/D, and bands 14q32.1 and Xq28, where the TCL1 and MTCP1 putative oncogenes have been identified. These genes encode two homologous proteins, p14(TCL1) and p13(MTCP1) respectively, which share no similarity with other known proteins. To determine the oncogenic role of MTCP1, transgenic mice with an expression of MTCP1 targetted to the T-cells were generated. A lymphoïd malignancy similar to Human T-PLL occurred in to independent transgenic lines with a high level of expression of the transgene. The cumulative incidence of the disease at 20 months was 100% and 50% respectively, and null in the control group. The oncogenic role of MTCP1 is demonstrated, and the p13(MTCP1) and p14(TCL1) proteins form a new oncoprotein family. The long latency period before emergence of tumors suggests that activation of MTCP1 is not sufficient to generate the malignant transformation. The secondary genetic events implicated in tumoral progression remain to be elucidated, in order to reconstruct the molecular history of the disease.