Progress on the mechanistic research of the trinucleotide repeat instabilities underlying human neurodegenerative diseases.

The expansion and deletion instabilities shown by some trinucleotide repeated DNA sequences are associated with more than 50 neurodegenerative diseases in humans. The increase or decrease of the trinucleotide repeat units underlying the diseases are not yet clearly explained using any mechanism, but has been found to affect the expression of specific genes, or produces cytotoxic RNA and protein, which has now become a common pathological mechanism of the diseases. The ongoing studies have shown that the changes in the copy numbers of the disease-related trinucleotide repeats may result from abnormal DNA replication, repair, recombination, and gene transcription.

Transcriptional network constituted of CBP, Ku70, NOX2, and BAX prevents the cell death of necrosis, paraptosis, and apoptosis in human melanoma.

CREB-binding protein (CBP) is an acetyltransferase known to play multiple roles in the transcriptions of genes involving oxidative metabolism, cell cycle, DNA damage checkpoints, and cell death. In this study, CBP was found to positively regulate the expression of Ku70, and both CBP and Ku70 were found to negatively regulate the expression of NOX2, therefore, mitigating the intracellular ROS in human melanoma. Knocking down CBP or Ku70 induced necrotic and paraptotic cell death as indicated by high-level intracellular ROS, cytoplasmic vacuolization, and cell cycle arrest in the S phase.