Effort-related decision making in humanized COMT mice: Effects of ValMet polymorphisms and possible implications for negative symptoms in humans.

Catechol-o-methyltransferase (COMT) is an enzyme that metabolizes catecholamines, and is crucial for clearance of dopamine (DA) in prefrontal cortex. ValMet polymorphism, which causes a valine (Val) to methionine (Met) substitution at codon 158, is reported to be associated with human psychopathologies in some studies. The Val/Val variant of the enzyme results in higher dopamine metabolism, which results in reduced dopamine transmission.

A large-scale drug screen identifies selective inhibitors of class I HDACs as a potential therapeutic option for SHH medulloblastoma.

Background: Medulloblastoma (MB) is one of the most frequent malignant brain tumors of children, and a large set of these tumors is characterized by aberrant activation of the sonic hedgehog (SHH) pathway. While some tumors initially respond to inhibition of the SHH pathway component Smoothened (SMO), tumors ultimately recur due to downstream resistance mechanisms, indicating a need for novel therapeutic options.

Methods: Here we performed a targeted small-molecule screen on a stable, SHH-dependent murine MB cell line (SMB21).