LAUSR

Acute myeloid leukaemia (AML) is a severe systemic malignancy this enzyme (the enzyme has three subunits – structural (A), regulatory originated from self-renewing transformed immature myeloid precursors. AML can often be a fatal disease since transformed cells operate highly effective machinery which allows them to protect themselves against induction of programmed cells death and also to suppress anti-cancer activity of natural killer (NK) and cytotoxic T cells (CTCs) thus evading immune attack [4, 6]. These biochemical networks act as a “multilayer protection cover” for AML cells since even if they are attacked by the immune cells, their killing becomes problematic due to effectiveness of anti-apoptotic machinery. Therefore, it is crucially important to understand themechanisms underlying functional activity of anti-apoptotic biochemical networks operated by AML cells in order to select optimal targets and design new drugs for successful and efficient therapy. In the study published in this issue of EBioMedicine, Ruvolo and colleagues have demonstrated that two biochemical cell survival pathways controlled by galectin-3 (a beta-galactoside-binding protein) and cluster of differentiation (CD) 74 (a signalling receptor and a chaperone for major histocompatibility complex type II proteins which are involved in antigen presentation) are cross-linked in a biochemical protein network, which is associated with poor survival of AML patients [7]. Importantly, this invaluable clinical study was performed using samples obtained from a large number of AML patients (511 in total) with newly diagnosed disease when malignant cells normally display high pro-survival and immune evasion activities. The study reports that galectin-3 expression is prognostic for poor survival rate of AMLpatients. Survival rate of AML patients with galectin-3 positive malignant cells was even lower when CD74-dependent signalling networks (in particular, the one involving transmembrane receptor known as CD44) were active. Intriguingly, the study reported galectin-3 to act as a negative regulator of the protein phosphatase 2A (PP2A), the enzyme involved in deactivation of several intracellular signalling cascades (see below). It was shown that galectin-3 affects regulatory (B) subunit of