Overexpression of the ras-related rab2 gene product in peripheral blood mononuclear cells from patients with hematological and solid neoplasms.

The rab2 gene product belongs to the rab branch of the ras-related GTP-binding protein family. The rab2 gene mRNA analysis in 70 tumor samples from various origins showed no obvious difference between malignant tissues and their normal counterparts. However, an over-expression has been observed at the RNA or protein levels in peripheral blood mononuclear cells from the nine patients with Sézary syndromes studied. Subsequent investigations in mycosis fungoides and solid tumor patients allowed us to link these high protein levels to immune reactive rather than to malignant cells. Circulating monocyte and lymphocyte populations from cancer patients are under analysis to correlate the Rab2 protein overexpression to a peculiar subset of cells.