Research that NaB regulates the expression not only genes involved with metabolic pathways, inflammation, cell proliferation but also caused significant changes in vivo in the expression of genes related to epigenetic regulatory mechanisms such as hdac11
, ehmt2, and dicer1 (Terova et al., 2016).
In accordance with their structural diversity, HDACs are divided into four subtypes: Class I (HDAC1, HDAC2, HDAC3, and HDAC8), Class II consisting of IIa (HDAC4, HDAC5, HDAC7, and HDAC9) and IIb (HDAC6 and HDAC10), Class III (a family of sirtuins), and Class IV (HDAC11
The HDACs are grouped into four classes: class I (HDACs 1,2, 3, and 8), class II (HDACs 4,5, 6,7,9, and 10), class III (SIRT1, SIRT2, SIRT3, SIRT4, SIRT5, SIRT6, and SIRT7), and class IV (HDAC11
) [74, 75].
In glioblastoma, the expression of HDAC1 and HDAC3 is inversely correlated with survival of GB patients, whereas that of HDAC4, HDAC5, HDAC6, and HDAC11
is positively correlated with survival of glioma patients .
In humans, 18 HDACs have been discovered and they are classed into four main families: class I (HDACs 1, 2, 3, and 8), class II (HDACs 4, 5, 6, 7, 9, and 10), class III (SIRT1, SIRT2, SIRT3, SIRT4, SIRT5, SIRT6, and SIRT7), and class IV (HDAC11
Atadja, "Cloning and functional characterization of HDAC11
, a novel member of the human histone deacetylase family," Journal of Biological Chemistry, vol.
Histone deacetylases are generally classified into four different classes, namely, HDACs 1-3 and 8, belonging to Class I and related to homologous to Rpd3, HDAC 4-7, 9-10 are Class II related to Hda1, Sirt 1-7 are Class III and are similar to Sir2 and HDAC11
belongs to Class IV.
The HDAC family comprises 11 different enzymes, sequentially named HDAC1 through HDAC11
. The cancer drugs contained a cocktail of the HDAC inhibitors targeting a mix of the enzymes.
Class IV HDAC11
shares conserved residues with both class I and II HDACs [7-9].
Searching for a solution to this dilemma, Witt's team came across a member of the HDAC family, HDAC11, which was identified only recently.
The researchers could show that many cancer cells, including cells of breast, liver and renal cancers, produce extraordinary high levels of HDAC11. This has not been observed in healthy cells, and hardly any specific functions of HDAC11 are known there.
Class III HDACs are sirtuins (SIRT1-7) and class IV consists of a solitary member HDAC11
, which is homologous to Rpd3 and Hda1 proteins of yeast (Figure 2) .