CD44 activation enhances acute monoblastic leukemia cell survival via Mcl-1 upregulation.

Survival of acute myeloid leukemia (AML) cells is regulated by their adherence to bone marrow stromal environment. Several adhesion molecules mediate interactions between AML cells and stroma, but their specific role in AML cell survival is still poorly understood. Here, we show that CD44 activation with the Hermes-3 monoclonal antibody enhances primary AML5 blast survival and increases apoptosis resistance of THP-1 monoblastic leukemia cells.

CD44 targeting reduces tumour growth and prevents post-chemotherapy relapse of human breast cancers xenografts.

CD44 is a marker of tumour-initiating cells and is upregulated in invasive breast carcinoma; however, its role in the cancer progression is unknown. Here, we show that antibody-mediated CD44-targeting in human breast cancer xenografts (HBCx) significantly reduces tumour growth and that this effect is associated to induction of growth-inhibiting factors. Moreover, treatment with this antibody prevents tumour relapse after chemotherapy-induced remission in a basal-like HBCx.