JQ1 is a

thienotriazolodiazepine A thienotriazolodiazepine is a heterocyclic compound containing a diazepine ring fused to thiophene and triazole rings. Thienotriazolodiazepine forms the central core of several pharmaceutical drugs including: * α-Hydroxyetizolam * Brotizolam ...

and a potent inhibitor of the BET family of

bromodomain A bromodomain is an approximately 110 amino acid protein domain that recognizes acetylated lysine residues, such as those on the ''N''-terminal tails of histones. Bromodomains, as the "readers" of lysine acetylation, are responsible in transducin ...

proteins which include BRD2, BRD3,

BRD4 Bromodomain-containing protein 4 is a protein that in humans is encoded by the ''BRD4'' gene. BRD4 is a member of the BET (bromodomain and extra terminal domain) family, which also includes BRD2, BRD3, and BRDT. BRD4, similar to other BET fam ...

, and the testis-specific protein BRDT in mammals.

BET inhibitor BET inhibitors are a class of drugs that reversibly bind the bromodomains of Bromodomain and Extra-Terminal motif (BET) proteins BRD2, BRD3, BRD4, and BRDT, and prevent protein-protein interaction between BET proteins and acetylated histones a ...

s structurally similar to JQ1 are being tested in clinical trials for a variety of cancers including NUT midline carcinoma. It was developed by the James Bradner laboratory at Brigham and Women's Hospital and named after chemist Jun Qi. The chemical structure was inspired by patent of similar BET inhibitors by Mitsubishi Tanabe Pharma. Structurally it is related to

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

s. While widely used in laboratory applications, JQ1 is not itself being used in human clinical trials because it has a short half-life.

Efficacy in mouse models of cancer

Interest in JQ1 as a cancer therapeutic stemmed from its ability to inhibit BRD4 and BRD3, both of which form fusion oncogenes that drive NUT midline carcinoma. Subsequent work demonstrated that a number of cancers including some forms of

acute myelogenous leukemia Acute myeloid leukemia (AML) is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal cells that build up in the bone marrow and blood and interfere with normal blood cell production. Symptoms may includ ...

(AML),

multiple myeloma Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibody, antibodies. Often, no symptoms are noticed initially. As it progresses, bone ...

(MM), and

acute lymphoblastic leukemia Acute lymphoblastic leukemia (ALL) is a cancer of the Lymphocyte, lymphoid line of blood cells characterized by the development of large numbers of lymphoblast, immature lymphocytes. Symptoms may include feeling tired, pale skin color, fever, ...

(ALL) were also highly sensitive to BET inhibitors.

In other applications

JQ1 has also been investigated for other applications in the treatment of

HIV The human immunodeficiency viruses (HIV) are two species of '' Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the im ...

infection, as a male contraceptive, and in slowing the progression of heart disease. JQ1 has been functionalized in numerous different studies of targeted protein degradation. For example, conjugation of JQ1 to phthalimide moieties such as that found in

thalidomide Thalidomide, sold under the brand names Contergan and Thalomid among others, is an oral administered medication used to treat a number of cancers (e.g., multiple myeloma), graft-versus-host disease, and many skin disorders (e.g., complication ...

recruits the

E3 ubiquitin ligase A ubiquitin ligase (also called an E3 ubiquitin ligase) is a protein that recruits an E2 ubiquitin-conjugating enzyme that has been loaded with ubiquitin, recognizes a protein substrate, and assists or directly catalyzes the transfer of ubiquitin ...

cereblon (CRBN) to effect proteasomal degradation of BRD4. Monovalent degraders based on functionalizing JQ1 have also been discovered. Fusion of JQ1 to other molecules targeting specific genomic loci has been demonstrated to rewire transcription.

References

{{Reflist, 32em Contraception for males Experimental cancer drugs Thienotriazolodiazepines Tert-butyl compounds

Efficacy in mouse models of cancer

In other applications

See also

References