Description
FOXO1 is highly expressed in normal B cells and in most types of non-Hodgkinl lymphoma. In Hodgkin and Reed-Sternberg cells of classical Hodgkin lymphoma(cHL) expression of FOXO1 is low or absent. We overexpressed constitutively active mutant of FOXO1 fused in frame with estrogen receptor ligand-binding domain (FOXO1(3A)ER), which can be activated by 4-Hydroxytamoxifen (4-OHT), in cHL cell lines KM-H2 and L428. Activation of the FOXO1 with 4-OHT resulted in inhibition of proliferation and apoptosis. Using gene-expression array we found that FOXO1 activates transcription of known and potential tumor suppressor genes: CDKN1B, PMAIP1, BCL2L11, TNFSF10, FBXO32, CBLB). Of note, FOXO1 repressed transcription of several cytokines and cytokine receptors, which are known tobe involved in pathogenesis of cHL (e.g. CCL5, CXCR5, TNFRSF8). Taken togather our data indicate important role of FOXO1 repression in pathogenesis of cHL.