We have previously reported that lead acetate activates protein kinase Calpha (PKCalpha) and induces DNA synthesis in human 1321N1 astrocytoma cells. In this study, we investigated the ability of lead to activate the mitogen-activated protein kinase (MAPK) cascade. We found that exposure to lead acetate (1-50 microM) resulted in concentration- and time-dependent activation of MAPK (extracellula...

Single channel currents from Ca-activated K channels were recorded from cell-attached patches, which were then excised from 1321N1 human astrocytoma cells. Cells were depolarized with K (110 mM) so that the membrane potential was known in both patch configurations, and the Ca ionophore A23187 or ionomycin (20-100 microM) was used to equilibrate intracellular and extracellular [Ca] (0.3 or 1 mic...

Glioblastoma, the most aggressive type of primary brain tumour, shows worse prognosis linked to diabetes or obesity persistence. These pathologies are chronic inflammatory conditions characterized by altered profiles of inflammatory mediators, including leptin and secreted phospholipase A2-IIA (sPLA2-IIA). Both proteins, in turn, display diverse pro-cancer properties in different cell types, in...

Adenosine 5'-diphosphate (ADP) plays a central role in regulating platelet function by the activation of the G protein-coupled receptors P2Y(1) and P2Y(12). Although it is well established that aggregation responses of platelets to ADP desensitize, the underlying mechanisms involved remain unclear. In this study we demonstrate that P2Y(1)- and P2Y(12)-mediated platelet responses desensitize rap...

OBJECTIVE MiR-302-367 is a cluster of polycistronic microRNAs that are exclusively expressed in embryonic stem (ES) cells. The miR-302-367 promoter is functional during embryonic development but is turned off in later stages. Motivated by the cancer stem cell hypothesis, we explored the potential expression of miR-302 in brain tumor cell lines. MATERIALS AND METHODS In the present experimenta...

Thimerosal (ethylmercurithiosalicylic acid), an ethylmercury (EtHg)-releasing compound (49.55% mercury (Hg)), was used in a range of medical products for more than 70 years. Of particular recent concern, routine administering of Thimerosal-containing biologics/childhood vaccines have become significant sources of Hg exposure for some fetuses/infants. This study was undertaken to investigate cel...

In 1321N1 astrocytoma cells, heterotrimeric G-protein-coupled receptors that activate phosphoinositide-specific phospholipase Cbeta (PLCbeta) isoforms via G(q), induced a prolonged activation of protein kinase B (PKB) after a short delay. For example, the effect of carbachol acting on M3 muscarinic receptors is blocked by wortmannin, suggesting it is mediated via a phosphoinositide 3-kinase (PI...

Globally, death due to cancers is likely to rise to over 20 million by 2030, which has created an urgent need for novel approaches to anticancer therapies such as the development of host defence peptides. Cn-AMP2 (TESYFVFSVGM), an anionic host defence peptide from green coconut water of the plant Cocos nucifera, showed anti-proliferative activity against the 1321N1 and U87MG human glioma cell l...