Arsenic used to treat leukemia

April 12, 2010 by Lin Edwards, Medical Xpress report
Massive native arsenic with quartz and calcite. Marie-aux-mines, Alsace, France. Photo taken at the Natural History Museum, London. (via Wikipedia)

(PhysOrg.com) -- Arsenic, known in the West mainly as a poison, has been used in traditional Chinese medicine for around two thousand years for the treatment of conditions such as syphilis and psoriasis. It has also been shown to have a substantial anti-cancer effect for a type of leukemia, but until now no one has known the mechanism for this effect. Now scientists in China have discovered arsenic targets proteins that contribute to the growth of cancer cells.

The researchers from China and France, led by Xiao-Wei Zhang of the State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, wanted to find out how works. The group, which included the Chinese Health Minister Chen Zhu, found that arsenic trioxide (As2O3) acts by promoting the degradation of a protein that encourages the growth of acute promyelocytic leukemia (APL) cells, although a detailed mechanism of how it works has yet to be established.

It was already known that a fusion protein called PML-RARalpha is produced as a result of a genetic mutation in APL, and this protein is essential to the growth and survival of the . When arsenic trioxide is present, a known as SUMO tags the fusion protein, which is then destroyed. When the protein is destroyed, the cancer cell can no longer survive. What the new research demonstrated was that As2O3 binds to a part of the protein called a zinc finger, which is rich in cysteine residues. As a result several protein molecules join together to form an insoluble protein, and the aggregate is then bound by SUMO, which destroys it.

APL affects the blood and bone marrow, and causes a drop in production of normal and platelets. Until the 1970s there was no effective treatment for the disease and the death rate was virtually 100%, but in 1992 a group of Chinese doctors demonstrated the effectiveness of arsenic in treating the disease. Now, as a result of treating APL with arsenic in China, over 90 per cent of patients survive at least five years with no signs of the disease.

Arsenic treatment has an advantage over chemotherapy because there is a lower incidence of side effects such as hair loss and suppression of the immune system. Many other countries now use arsenic in the treatment of APL, but some doctors refuse to recommend it, and some patients refuse to accept it because of its reputation as a poison.

The paper was published on 9 April, in the journal Science.

More information: Arsenic Trioxide Controls the Fate of the PML-RAR-[alpha] Oncoprotein by Directly Binding PML, Science 9 April 2010: Vol. 328. no. 5975, pp. 240 - 243, DOI:10.1126/science.1183424

Related Stories

Recommended for you

Researchers develop swallowable test to detect pre-cancerous Barrett's esophagus

January 17, 2018
Investigators at Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center have developed a simple, swallowable test for early detection of Barrett's esophagus that offers promise ...

Scientists zoom in to watch DNA code being read

January 17, 2018
Scientists have unveiled incredible images of how the DNA code is read and interpreted—revealing new detail about one of the fundamental processes of life.

T-cells engineered to outsmart tumors induce clinical responses in relapsed Hodgkin lymphoma

January 16, 2018
WASHINGTON-(Jan. 16, 2018)-Tumors have come up with ingenious strategies that enable them to evade detection and destruction by the immune system. So, a research team that includes Children's National Health System clinician-researchers ...

Researchers identify new treatment target for melanoma

January 16, 2018
Researchers in the Perelman School of Medicine at the University of Pennsylvania have identified a new therapeutic target for the treatment of melanoma. For decades, research has associated female sex and a history of previous ...

More evidence of link between severe gum disease and cancer risk

January 16, 2018
Data collected during a long-term health study provides additional evidence for a link between increased risk of cancer in individuals with advanced gum disease, according to a new collaborative study led by epidemiologists ...

Researchers develop a remote-controlled cancer immunotherapy system

January 15, 2018
A team of researchers has developed an ultrasound-based system that can non-invasively and remotely control genetic processes in live immune T cells so that they recognize and kill cancer cells.

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Bonkers
not rated yet Apr 12, 2010
Arsenic, forgive me if i'm wrong, but don't you get immunity from it if you consume regularly? - I'm sure there was one King of England that took it regularly as a precaution against poisoning.
mattytheory
5 / 5 (1) Apr 12, 2010
Aren't the drugs used in chemotherapy poison too? Oh wait, someone is making a profit off it so we don't call it poison we call it medicine...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.