Effect of missense mutations on structure and interaction of anaplastic lymphoma kinase [ALK] in neuroblastoma

Neuroblastoma is a cancer of the sympathetic nervous system, accounting for upto 15% of childhood cancer mortality. It can occur in many areas but most of them begin in the abdomen in the adrenal gland and can spread to the bones and other areas. http:/en.wikipedia.org/wiki/Neuroblastoma-cite_note-pmid19383347-3. Unfortunately, like other cancers, its causes are still poorly understood. Anaplastic lymphoma kinase [ALK], a membrane associated tyrosine kinase was recently found to be mutated in neuroblastoma. Protein sequence of ALK was retrieved from UniProt and the seven identified mutations were substituted in native sequence to get its mutant proteins. Significant changes were explored in the mutant secondary structures when compared with the native protein. Changes were also observed in the physiochemical properties and it can therefore be inferred that, these changes may be translated in the tertiary structures due to their effects on the folding pattern. Tertiary structure of the protein modeled after refinement and validation was submitted to Protein Model Database [PMDB] and was assigned with the PMDB ID P0077827. RMSD values of the mutant structures were observed deviated from the native structure when compared with probability < 0.05. It was observed that there are a total of 15 Disordered Regions in the protein having a total of 290 Disordered Residues. Protein-ligand interaction analysis was performed to investigate the effects of mutations damaging its interactions and it was observed that the mutations understudy affects its interactions with ATP which ultimately results in causing neuroblastoma. This study was based on the in silico mutation analysis of Seven missense mutations of anaplastic lymphoma kinase which can better explain why missense mutations in ALK protein cause neuroblastoma. Structure and sequence based computations were systematically and comprehensively evaluated applied to the mutants in anaplastic lymphoma kinase and on the basis of our observations a detailed structural explanations have been developed for the measured and predicted impact of these missense substitutions

Effect of iron on the activation of the MAPK/ERK pathway in PC12 neuroblastoma cells

Recent evidence suggests that reactive oxygen species function as second messenger molecules in normal physiological processes. For example, activation of N-Methyl-D-Aspartate receptor results in the production of ROS, which appears to be critical for synaptic plasticity, one of the cellular mechanisms that underlie learning and memory. In this work, we studied the effect of iron in the activation of MAPK/ERK pathway and on Ca2+ signaling in neuronal PC12 cells. We found that iron-dependent generation of hydroxyl radicals is likely to modulate Ca2+ signaling through RyR calcium channel activation, which, in turn, activates the MAPK/ERK pathway. These findings underline the relevance of iron in normal neuronal function.

Naltrexone influences protein kinase C epsilon and integrin alpha7 activity in SH-SY5Y neuroblastoma cells

Alcohol influences the neuroadaptation of brain cells where receptors and enzymes like protein kinase C (PKC) exist. Naltrexone acts on opioid receptors. However, other mechanisms of action remain unknown. We prepared SH-SY5Y neuroblastoma cells, and fed them with 150 mM ethanol for 72 h followed by treatment with naltrexone for 24 h. We performed microarray analysis and reverse transcriptase-polymerase chain reaction. Our results showed that PKC epsilon increased 1.90 times and showed an overall decreasing pattern as time increased. Phosphorylated ERK also increased 2.0 times according to the change of PKC epsilon. Integrin alpha7 increased 2.32 times and showed an increasing pattern as time increased. In conclusion, naltrexone influences PKC epsilon neuronal signaling system and endothelial adhesion molecule integrin alpha7 in addition to the well-known opioid system.

Caffeine Induces Apoptosis in Human Neuroblastoma Cell Line SK-N-MC

Caffeine is one of the most widely consumed neuroactive drugs, coming mostly from everyday beverages such as coffee and tea. To investigate whether caffeine induces apoptosis in the central nervous system, 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, flow cytometric analysis, DNA fragmentation assay, and caspase-3 enzyme assay were performed on SK-N-MC human neuroblastoma cells. Cells treated with caffeine at concentrations as high as 10 mM exhibited several characteristics of apoptosis. In addition, caffeine was shown to increase the caspase-3 activity. These results suggest that high-dose of caffeine induces apoptosis in human neuroblastoma cells, probably by increasing the caspase-3 enzyme activity.