Zosuquidar trihydrochloride
Encyclopedia
Zosuquidar is a compound
of antineoplastic drug
candidates currently under development. It is now in "Phase 3" of clinical tests in the United States. Its action mechanism consists of the inhibition of P-glycoprotein
s; other drugs with this mechanism include tariquidar
and laniquidar
. P-glycoproteins are protein
s which
convert the energy
derived from the hydrolysis
of ATP
to structural changes in protein molecules, in order to perform coupling
, thus discharging medicine
from cells. If P-glycoprotein coded with the MDR1 gene
manifests itself in cancer cell
s, it discharges much of the antineoplastic drugs from the cells, making cancer cell
s medicine tolerant, and rendering antineoplastic drugs ineffective. This protein also manifests itself in normal organs not affected by the cancer (such as the liver, small intestine, and skin cells in blood vessels of the brain), and participates in the transportation of medicine. The compound Zosuquidar inhibits this P-glycoprotein, causing the cancer cells to lose their medicine tolerance, and making antineoplastic drugs effective.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
of antineoplastic drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...
candidates currently under development. It is now in "Phase 3" of clinical tests in the United States. Its action mechanism consists of the inhibition of P-glycoprotein
P-glycoprotein
P-glycoprotein 1 also known as multidrug resistance protein 1 or ATP-binding cassette sub-family B member 1 or cluster of differentiation 243 is a glycoprotein that in humans is encoded by the ABCB1 gene...
s; other drugs with this mechanism include tariquidar
Tariquidar
Tariquidar is a P-glycoprotein inhibitor undergoing research as an adjuvant against multidrug resistance in cancer....
and laniquidar
Laniquidar
Laniquidar is a P-glycoprotein inhibitor undergoing clinical studies for acute myeloid leukemia and myelodysplastic syndrome ....
. P-glycoproteins are protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s which
convert the energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
derived from the hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
of ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
to structural changes in protein molecules, in order to perform coupling
Coupling
A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. Couplings do not normally allow disconnection of shafts during operation, however there are torque limiting couplings which can slip or disconnect when some torque limit is exceeded.The...
, thus discharging medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
from cells. If P-glycoprotein coded with the MDR1 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
manifests itself in cancer cell
Cancer cell
Cancer cells are cells that grow and divide at an unregulated, quickened pace. Although cancer cells can be quite common in a person they are only malignant when the other cells fail to recognize and/or destroy them. In the past a common belief was that cancer cells failed to be recognized and...
s, it discharges much of the antineoplastic drugs from the cells, making cancer cell
Cancer cell
Cancer cells are cells that grow and divide at an unregulated, quickened pace. Although cancer cells can be quite common in a person they are only malignant when the other cells fail to recognize and/or destroy them. In the past a common belief was that cancer cells failed to be recognized and...
s medicine tolerant, and rendering antineoplastic drugs ineffective. This protein also manifests itself in normal organs not affected by the cancer (such as the liver, small intestine, and skin cells in blood vessels of the brain), and participates in the transportation of medicine. The compound Zosuquidar inhibits this P-glycoprotein, causing the cancer cells to lose their medicine tolerance, and making antineoplastic drugs effective.