Background:

Description:

IC50: 9 μM

The main function of the proteasome is to degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Proteasome inhibition is now considered a unique and effective way to kill cancer cells that can tolerate conventional chemotherapy. K-7174 is a novel orally active proteasome inhibitor.

In vitro: Due to its proteasome inhibitary effect, K-7174 induces transcriptional repression of class I histone deacetylases (HDAC) via caspase-8-dependent degradation of Sp1, the most potent transactivator of class I HDAC genes. HDAC1 overexpression reduces the cytotoxic effect of K-7174 and abrogates histone hyperacetylation without affecting the ubiquitinated protein accumulation in K-7174-treated myeloma cells [1].

In vivo: K-7174 exhibits the therapeutic effects through its anti-proteasome activities, which is stronger when administered orally than intravenously, without obvious side effects in a murine myeloma model. In addition, K-7174 kills bortezomib-resistant myeloma cells carrying a β5-subunit mutation in vivo and primary cells from a patient resistant to bortezomib [1].

Clinical trial: Up to now, K-7174 is still in the preclinical development stage.

Reference:
[1] Kikuchi J, Yamada S, Koyama D, Wada T, Nobuyoshi M, Izumi T, Akutsu M, Kano Y, Furukawa Y.  The novel orally active proteasome inhibitor K-7174 exerts anti-myeloma activity in vitro and in vivo by down-regulating the expression of class I histone deacetylases. J Biol Chem. 2013 Aug 30;288(35):25593-602.