Scriptaid (GCK1026) is an inhibitor of HDAC, and has a greater effect on acetylated H4 than H3.

Scriptaid (6 μM) results in a >100-fold increase in histone acetylation in PANC-1 cell. Scriptaid (8 μM) is not lethal to PANC-1 cell and has limited effects (80% survival) on MDAMB-468. Scriptaid increases the transcription of pCMVb, p6SBE-luc and p6MBE-luc independent of a positive inducer of transcription. Scriptaid is capable of inducing high expression of p6MBE-luc, pCMVb, and pUB6/V5-LacZ, driven by viral (SV40 and CMV) or human (ubiquitin c, UB6) promoters, which do not depend on the specificity of the enhancer (SBE versus MBE), the type of promoter (viral versus cellular), the product of the reporter gene (luciferase versus b-gal), nor on the integration status of the reporter construct. [1] Scriptaid induces high rates of somatic cell nuclear transfer (SCNT) oocytes development to the blastocyst stage and allowed full-term development (3.4, 4.2, 7.6, 6.8, and 4.1%) with all concentrations (50, 100, 250, 500, and 2000 nM respectively). Scriptaid improves the full-term development of cloned B6D2F1embryos in a dose-dependent manner with the maximum effect at 250 nM. Scriptaid enables the clone of all the important inbred mouse strains, such as C57BL/6, C3H/He, DBA/2, and 129/Sv. Scriptaid treatment enhances newly synthesized mRNA levels in cloned embryos. 250 nM Scriptaid treated for up to 48 h, does not inhibit the development of ICSI-fertilized embryos. [2] Scriptaid inhibits T. gondii tachyzoite proliferation with IC50 of 39 nM. Scriptaid (0.225 μM) completely protects the HS68 monolayers from T. gondii tachyzoite. [3] Scriptaid inhibits growth of ER negative cell lines, MDA-MB-231, MDA-MB-435 and Hs578t with IC50 of 0.5-1.0 μg/mL after 48 h treatment. 1 μg/ml Scriptaid treated for 48 h induces an accumulation of both acetylated H3 and acetylated H4 histone tail proteins, and a maximal of 20,000-fold increase of ER mRNA transcript. [4]

Scriptaid elicits a dose-dependent decrease in lesion size (a maximal decrease of 45%) at 1.5 to 5.5 mg/kg and a concomitant attenuation in motor and cognitive deficits when delivered 30 minutes postinjury in a model of mode rate TBI. Comparable protection is achieved even when treatment is delayed to 12 h postinjury. The protection of motor and cognitive functions is long lasting, as similar improvements are detected 35 days postinjury. Scriptaid induces an increase in surviving neurons (42%), as well as the number/length of their processes within the CA3 region of the hippocampus and the pericontusional cortex. Scriptaid treatment prevents the decrease in phospho-AKT (p-AKT) and phosphorylated phosphatase and tensin homolog deleted on chromosome 10 ( p-PTEN) induced by TBI in cortical and CA3 hippocampal neurons. [6] Scriptaid treatment (3.5 mg/kg) clearly inhibits tumor growth in a human breast cancer xenograft MDA-MB-231 model, reducing tumor volume by 75%. [4]

Immunoblotting assay of histone acetylation: PANC-1 cells are treated with 2 μg/mL of Scriptaid for 18 h in culture medium. Treated and untreated cells are harvested with trypsin-EDTA, washed with PBS, and resuspended in a protein sample buffer. Protein concentration is determined by BCA protein assay reagents. Fifty μg of proteins from each sample is loaded on a 12% denaturing polyacrylamide gel. Proteins are subsequently transferred to a nylon membrane using MilliblotGraphite Electroblotter I. The nylon membrane is incubated with rabbit antihuman acetyl-lysine antibody, followed by goat antirabbit antibody coupled to horseradish peroxidase, developed with SuperSignal substrates, and detected by film.

Cells are plated at a cell density of 5000 cells/well in 12 well plates and treated with Scriptaid for up to 3 days. Cells numbers are counted daily using a Coulter counter.(Only for Reference)