Expression and clinical significance of organic cation transporter family in glioblastoma multiforme.

Background: Solute carrier (SLC) 22 A1, A2, and A3 are polyspecific transporters transporting organic cations like histamine, serotonin, norepinephrine, dopamine, MPP + , and toxins. The expression of SLC22A1-A3 in cancer is seldom investigated, and the function of SLC22A1-A3 in glioblastoma multiforme (GBM) is never elucidated.

Materials: In our study, we detected the expression of SLC22A1-A3 in 11 fresh GBMs and tumor-adjacent brain tissues with qPCR, and in 129 paraffin-embedded GBMs with immunohistochemistry (IHC).

Molecular mechanism of ERK dephosphorylation by striatal-enriched protein tyrosine phosphatase.

Striatal-enriched tyrosine phosphatase (STEP) is an important regulator of neuronal synaptic plasticity, and its abnormal level or activity contributes to cognitive disorders. One crucial downstream effector and direct substrate of STEP is extracellular signal-regulated protein kinase (ERK), which has important functions in spine stabilisation and action potential transmission. The inhibition of STEP activity toward phospho-ERK has the potential to treat neuronal diseases, but the detailed mechanism underlying the dephosphorylation of phospho-ERK by STEP is not known.

Cadmium is a potent inhibitor of PPM phosphatases and targets the M1 binding site.

The heavy metal cadmium is a non-degradable pollutant. By screening the effects of a panel of metal ions on the phosphatase activity, we unexpectedly identified cadmium as a potent inhibitor of PPM1A and PPM1G. In contrast, low micromolar concentrations of cadmium did not inhibit PP1 or tyrosine phosphatases.