Chemistry provides a new supply of a promising cancer and HIV treatment

October 12, 2017
Credit: CC0 Public Domain

A drug isolated from a marine pest holds promise for treating some of the world's nastiest diseases, and researchers would love to find out just how effective it is - if only they could get their hands on more. As it stands, the world's supply of the chemical is down to about half of what it was in the 1990s, and it is hard to extract in sufficient quantities from the feathery sea creatures that produce it.

Now, Stanford researchers have found a simpler and more efficient way to make this increasingly in-demand compound in the lab, they report October 6 in the journal Science. Their new synthetic supply will be enough to continue ongoing trials testing its effectiveness as a cancer immunotherapy and for treating Alzheimer's disease and HIV, for which any further supply was until now uncertain.

Principal investigator Paul Wender, a professor of chemistry and member of Stanford ChEM-H, said he got so excited about the project at one point, "I put on my lab coat and did some crystallizations," one of the basic steps of chemistry lab work usually left to students, not full professors. For him, the new paper is the result of decades of work and a happy accident in the Gulf of Mexico almost 50 years ago.

From three elephants to a salt shaker

Like many other naturally occurring chemicals put into service as pharmaceuticals, bryostatin was discovered following what was essentially a fishing expedition. In the 1960s, having had some success developing drugs from terrestrial flora and fauna, scientists began to shift attention to marine life.

The story of bryostatin itself began in 1968, when a marine biologist working in the Gulf of Mexico collected a plethora of marine organisms and sent them to the National Cancer Institute for analysis. One of those organisms, Bugula neritina, a pest best known for fouling up marine environments, showed some promise as an anti-cancer agent. A decade and a half later, researchers reported the structure of the active ingredient, which they dubbed bryostatin 1 after the animal's common name, brown bryozoan.

Unfortunately, bryostatin 1 is very hard to come by. When NCI scientists went back and swept up 14 tons of B. neritina, they managed to extract just 18 grams of bryostatin.

"It's basically three elephants going down to a salt shaker," Wender said.

Worse, subsequent studies showed that B. neritina produces bryostatin only in depths greater than about 10 feet and in warmer seas closer to the equator, and only during certain times of the year. (In fact, the NCI's 14-ton collection came from California, because subsequent samples from the Gulf of Mexico proved inactive.) And while there was a way to synthesize bryostatin in the lab, it took 57 steps and was not very efficient.

Improving on nature

Wender and his group have been working with bryostatin analogs - chemicals inspired by bryostatin, but not quite the same - since the 1980s but only recently began thinking about how to make bryostatin itself in a lab.

"Ordinarily, we're in the business of making chemicals that are better than the natural products" such as bryostatin, Wender said. Wender and his lab's job, in other words, is to come up with chemicals inspired by nature, but more effective.

"But when we started to realize that clinical trials a lot of people were thinking about were not being done because they didn't have enough material, we decided, 'That's it, we're going to roll up our sleeves and make bryostatin because it is now in demand,'" Wender said.

Dusting off the lab coat

After decades of experience with bryostatin analogs and two years of concerted effort, the lab came up with a much shorter, 29-step process and a yield of 4.8 percent, tens of thousands of times more efficient than extracting bryostatin from B. neritina, and substantially simpler and more efficient than the previous synthetic approach.

"The talent and dedication of this group made possible an achievement which many had thought impossible," Wender said. "We are so fortunate to have people who are undeterred by that."

The team members have now produced over 2 grams of bryostatin 1, and once production is scaled up, Wender said, they expect manufacturers could produce about 20 grams per year, enough to cover clinical and research needs. That is a bit more than was ever extracted from B. neritina and enough to treat about 20,000 cancer patients or 40,000 Alzheimer's patients.

The results could also be a boon for HIV/AIDS research. In late September, the team reported that a bryostatin 1 analog could help wake latent HIV-infected cells, making them more susceptible to attack by HIV drugs or the immune system. With new insight into - and a new supply of - bryostatin 1, Wender said, "we have an opportunity to start in earnest a clinical conversation about eradicating HIV/AIDS."

Explore further: Synthetic molecule 'kicks and kills' some persistent HIV in mice

More information: P.A. Wender el al., "Scalable synthesis of bryostatin 1 and analogs, adjuvant leads against latent HIV," Science (2017). science.sciencemag.org/cgi/doi … 1126/science.aan7969

Related Stories

Synthesized compound flushes out latent HIV

July 17, 2012

(Medical Xpress) -- A new collection of compounds, called "bryologs" – derived from a tiny marine organism – activate hidden reservoirs of the virus that currently make the disease nearly impossible to eradicate.

Researchers create molecule that could 'kick and kill' HIV

October 5, 2017

Current anti-AIDS drugs are highly effective at making HIV undetectable and allowing people with the virus to live longer, healthier lives. The treatments, a class of medications called antiretroviral therapy, also greatly ...

Marine moss reveals clues to anti-cancer compound

March 9, 2007

An Oregon Health & Science University researcher believes the discovery of a gene cluster from a bacterium that protects a moss-like marine invertebrate from predators may be the first step toward engineering cancer-fighting ...

Recommended for you

A new way to harness wasted methane

October 17, 2017

Methane gas, a vast natural resource, is often disposed of through burning, but new research by scientists at MIT could make it easier to capture this gas for use as fuel or a chemical feedstock.

Stiff fibres spun from slime

October 17, 2017

Nature is an excellent teacher – even for material scientists. Researchers, including scientists at the Max Planck Institute of Colloids and Interfaces, have now observed a remarkable mechanism by which polymer materials ...

Key to expanding genetic code described

October 17, 2017

Yale scientists have described the atomic structure of a protein that is the key tool in efforts by synthetic biologists to expand the genetic code.

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

thomasct
not rated yet Oct 12, 2017
A snippet of hope for treatment.. but no cure. FYI The 1939 UK Cancer Act forbids the publication of any Cancer Cure. In US, in 1985 Dr R Good developed the natural pancreatic cancer cure. He was the 1st bone marrow transplanter with 2000 paper published. He was refused by all Med Js. Not published makes it illegal for the doc to cure. H R Clark, PhD ND made 1/2M reproducible bio-resonance tests, identifying the causes and paths of all cancers. Many cures address her identified pathways.. they are Essiac, cannabis oil, Sunderlandia, curcumin, Rife & Beck & H R Clark electrical resonance, papaya leaf tea, Monatana Yew tip, Hoxeys herbs, J Winters Herbs etc. and to . follow Dr Clark;s protocols, who advised use as many cures you can get hold of. UK Med herbalists have many of these.
434a
5 / 5 (1) Oct 13, 2017
A snippet of hope for treatment.. but no cure. FYI The 1939 UK Cancer Act forbids the publication of any Cancer Cure.


No, the act prohibits the advertisement of cancer cures. The intent is to prevent abuse of vulnerable people by snake oil salesmen. Now I wonder where I read recently read someone promoting 'erbs to cure cancer hmmm. There is nothing in the act that would prevent the publication of research into cancer treatments. Anyone with a micro-second to spare can see such publications in the press. You sir are full of shit. Ignore you go on.

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.