Scientists have been able to isolate the genes of the poppy plant responsible for the synthesis of the medicinal compound noscapine, a promising cancer drug.
The researchers from University of York and GlaxoSmithKline Australia found that the pathway for synthesis of noscapine is controlled by a complex cluster of ten genes encoding five different enzyme classes.
The fact that the genes are grouped in a cluster means that plant breeding becomes faster and easier. Ultimately, they hope to develop high yielding commercial noscapine poppies in order to establish a reliable supply of the drug.
Noscapine and Cancer
Noscapine was identified over 200 years ago and has been used as a suppressant in cough mixtures for decades.
Researchers first discovered that noscapine may be useful in cancer treatment in 1998. Since then animal and human studies found that it can shrink breast and prostate cancers and possibly prevent metastasis (spread throughout the body) – a primary cause of cancer death.
Additional data suggests that noscapine may be effective for treatment-resistant ovarian cancers, multiple myeloma, lung cancer and colon cancer.
Early clinical trials are ongoing and have not been published, but because noscapine is an approved drug in some countries and has a good safety record, some physicians are already using it off-label to treat cancer.
Despite these encouraging results, noscapine’s full scale use as a cancer drug has been hampered by limited supply.
Commercial poppy farming traditionally involved lancing the seed capsule so that medicinal alkaloids, including noscapine, could be extracted.
Since the 1960s, commercial industrial techniques have largely switched to large scale poppy harvesting and extraction focused on other medicinal poppy alkaloids like morphine and thebaine used to manufacture pain medicines. This trend has developed at the expense of noscapine which until now was only available from traditional techniques.
With the discovery of noscapine-producing genes drug companies will be able to greatly accelerate the breeding of high-noscapine poppy varieties and boost production of the drug through more modern commercial techniques.
The University of York