Recent progress in the protein-tyrosine phosphatase SHP1 gene: the significant correlation of the SHP1 gene silencing with the onset of lymphomas/leukemias

Using cDNA expression array and tissue microarray, we comprehensively and systematically analyzed the expression profile to investigate the lymphomagenesis. We detected the significant decrease of hematopoietic cell specific protein-tyrosine phosphatase SHP1 gene expression in various malignant lymphomas and leukemias. High-frequent silencing of the SHP1 gene by promoter methylation was detected in various kinds of leukemias and lymphomas as well as in many hematopoietic cell lines. The promoter methylation of the SHP1 gene was significantly correlated with the clinical stage. Loss of heterozygosity with microsatellite markers around the SHP1 gene was detected in 79% of informative ALL cases. These results suggest that loss of functional SHP1 is closely associated with the pathogenesis of leukemias/lymphomas.