Issue Date: October 8, 2007
Liquid Gold Mine
AS YOUR PLANE descends into Tromsø in the far north of Norway, you have the sense of touching down on another planet. Surrounded by mountains, the city of 60,000 is in fact a series of islands and fjords, an interplay of greens and blues that is eerily breathtaking on even the foggiest of September days. This is the gateway to the Arctic, a place that enjoys midnight sun in the summer and the northern lights in the winter.
Head south through Bodø and Trondheim, and by the time you've made your way down to the capital city of Oslo, the fjords, rocky islands, mountains, and endless forests start to seem routine. Untouched beauty is just the way it is in Norway, and it's been that way for thousands of years.
It's easy to adopt the nonchalant attitude of Norwegians, who are almost blasé about the abundance of natural resources at their fingertips. Yet Norwegians also recognize that those natural resources are the lifeblood of their economy. Fishing and, more recently, offshore oil and natural gas drilling have made Norway a wealthy nation.
Norwegians are again looking to the seas for the next industrial wave: biotechnology. The plan is to tap into the therapeutic potential of novel compounds in the marine organisms found in the fjords and arctic waters off the country's craggy coast.
Aided by the government, universities, and a small number of industrial partners, scientists are launching a concerted "marine bioprospecting" effort. They have begun filing through the 4,000 marine invertebrates, 200 types of fish, 150 macroalgae, and 250 microalgae estimated to be thriving in Norwegian coastal waters. Throw in the high density of bacteria found in marine sediment, and suddenly, there's a lot to explore.
Bioprospecting is not a new concept. David J. Newman, chief of the Natural Products Branch of the National Cancer Institute (NCI), estimates that around 60% of the drugs on the market today are derived from or designed to resemble natural chemical products. Some obvious examples are paclitaxel, the breast cancer drug originally derived from the bark of the Pacific yew tree, or artemisinin, the malaria treatment made from the sweet wormwood plant. And many of the antibiotics we take were discovered in soil samples.
"The answer might be under your feet," quips Trond E. Ellingsen, biotechnology research director at Norway's Sintef, the largest independent research organization in Scandinavia. "It just depends on where you've walked."
EVEN THE NOTION of trawling the ocean for drugs has been around since the 1970s, though the focus has been on tropical waters. Scientists have long been intrigued by the extreme conditions that some marine organisms endure. In order to survive, they must adapt to a wide range of temperatures, changes in salinity, high pressures at great depths, and high concentrations of halogens, to name just a few obstacles.
Yet despite a growing pipeline, the only "direct-from-the-sea" drug on the market today is the chronic pain treatment ziconotide, approved in late 2004 and sold by Elan Pharmaceuticals under the brand name Prialt. Though made synthetically, the product is identical to a peptide found in the venom of cone snails. A few other products have marine life "in their DNA," as Newman terms it, most notably the HIV medicine azidothymidine, which is structurally related to a compound made by a Caribbean sea sponge.
But scientists are getting better at figuring out how to turn the discoveries of the sea into viable drugs, and interest in the field appears to be growing, particularly as fewer novel compounds are being found from terrestrial sources.
The Norwegians believe they have several advantages when it comes to mining the sea for pharmaceutical gold. For one thing, the circulation pattern off the Norwegian coast mixes cold water from the Arctic with the warm water of the Gulf Stream, creating layers of temperatures that should encourage biodiversity.
For years, scientists thought there would be little diversity between global waters. They reasoned that the currents, not to mention the critters that cling to ships traveling far and wide, would ensure that the enzymes and other bioactive molecules found in the Arctic Ocean would be similar to those found, say, off the coast of Florida.
In fact, says Sergey B. Zotchev, a professor in the biotechnology department at the Norwegian University of Science & Technology (NTNU), in Trondheim, it is now understood that while a good portion of the microbes found in the ocean look similar, the secondary metabolites they produce differ widely. This is crucial to drug discovery and could give Norway another edge.
But perhaps the country's most important advantage is the element of the unknown: Quite simply, until recently, no one had bothered to look for drugs there.
NCI's Newman believes there is vast potential in the waters of Norway, be they the Arctic Ocean and Barents Sea off its northern coast or the fjords found throughout. "You have sources of invertebrates that nobody has looked at before," he points out. Furthermore, there is a huge range of bacteria with therapeutic promise living in those waters. "There are massive areas of the seabed and fjords where you can look for microbes that are marine in origin or have at least learned to coexist in the marine environment. The potential is enormous."
With billions of cells of bacteria per liter, salt water is a matrix of microorganisms struggling to survive, notes Geir Johnsen, a biology professor at NTNU who manages a research boat based in the Trondheim fjord. "When you are swimming in salt water, it's like swimming in spit," he says.
Researchers in Trondheim, which along with Tromsø is one of two hubs of marine bioprospecting activity in Norway, have been working since 2003 to access the therapeutic usefulness of those bugs in two ways: by collecting seawater and sediment and by sampling the larger organisms that hoard them.
NTNU's Zotchev has chosen to focus on sea sponges. They are the simplest of animals but are engaged in constant biological and chemical warfare against those billions of microbes, which means their pores could be storing prime antibacterial drug candidates.
That natural sponge used to exfoliate your back, it turns out, is more sophisticated than it appears. A sponge the size of a soccer ball will soak up hundreds of liters of water every day in search of its next meal. But in addition to attracting tasty treats, it also captures and filters bacteria and other microorganisms. Some of those bacteria turn out to be beneficial to the sea sponge, which then produces compounds that allow it and these guests to happily coexist.
Last year, Johnsen and Zotchev headed out on an expedition to harvest a range of sea sponges from the Trondheim fjord. Using cameras to monitor the seafloor, scientists directed a remotely operated vehicle to collect interesting sponges. On the boat, the sponges were cut into pieces, stored in seawater mixed with glycerin, which usually preserves the living bacteria, and later frozen to -80 oC. Back at the lab, the pieces were ground with a mortar and pestle, put in suspension, centrifuged, and placed on culture plates.
And then Zotchev's group waited. "When you first try to grow these bacteria, it might take up to six weeks to appear," he notes. Also, it can be tricky to create the right conditions for growth; the genes within the bacteria that express the desired compounds need the right environment to be turned on, and scientists must figure out those triggers.
The samples are then subjected to high-throughput screening to see if there is an inkling of activity that could have medical or other commercial relevance. The screening is conducted with robotic systems shared by NTNU and Sintef, the independent organization that helps commercialize research coming out of Trondheim.
Yet even after screening, scientists might wind up with known antibacterial compounds. The risk of duplication is augmented by prospecting in the fjords, where some of what is found in the water may actually be run-off from the glaciers and surrounding land.
If scientists find a hit and want to scale up to investigate further, NTNU and Sintef share process development facilities that enable a researcher to make enough material for preclinical trials. The labs boast fermenters ranging from 2 L up to 20 L and a pilot plant with 1,500-L vessels.
Zotchev plans to exploit the commercial potential of his sea-sponge pursuits by licensing promising hits through Biosergen, a company he founded in 2004 to develop analogs of the antifungal compound nystatin. So far, his research group, which is specifically interested in actinomycete bacteria, has identified more than 100 antibacterial and 33 antifungal hits, including some that they believe are new compounds.
Though he uses genetic manipulation to improve the molecules generated by bacteria, he expects that other techniques may be required to further develop those hits. Like many of the natural products found on land, a promising molecule may need to be modified to make a good drug candidate. As such, Zotchev has signed on with the contract chemistry firm ChemDiv, which is providing synthesis work.
Other research teams are focused on categorizing bacteria found in water collected from the fjord. A project led by Svein Valla, a professor in NTNU's biotechnology department, appears poised for commercialization. His team has developed a set of unique vectors that can insert genetic material into a broad range of hosts. Yet another project is focused on identifying pigments made by bacteria.
While the Trondheim scientists are focused on culturing bacteria found in seawater and sponges, researchers at the University of Tromsø are looking at anything and everything. They are attempting to create a "biobank" of the marine invertebrates, algae, and bacteria found in the arctic waters; search those organisms for useful compounds; and with the help of partners, develop the compounds into drugs or other commercial products.
THEIR PROJECT was officially launched in March with the formation of MabCent, the center for research-based innovation on marine bioactives and drug discovery. The University of Troms?? and the Norwegian Research Council, along with a small group of industrial partners, have provided the biobank program with $25 million in funding over the next eight years.
MabCent hit the water running. In May, about 25 scientists packed onto a research boat for a 10-day bioprospecting trip in Svalbard, a group of islands midway between Norway and the North Pole. Undeterred by the occasional polar bear that would pop up out of the ice, they brought back a boatload of samples.
Their collection has been further expanded by sampling from the fjord in Tromsø, a local resource that researchers say should not be overlooked. All told, they have enough samples to keep them busy for at least 18 months, according to Trond O. Jorgensen, director of MabCent.
Thanks to the extreme conditions the marine life endures, the Tromsø scientists believe they could have some unique, highly active compounds in their collection. "We're talking about organisms that have never seen temperatures greater than 5 oC," Jorgensen says. The theory is that the active molecules within those creatures have, over millions of years, evolved to become highly selective for their targets because synthesis is so slow in those conditions.
This selectivity means that cold-adapted molecules could make good drug candidates and could even prove to be efficient catalysts in industrial processes. Furthermore, they could enable "green" manufacturing because they are generally easy to inactivate: Just raise the temperature a bit and they turn off, says Kjersti Lie Gabrielsen, project manager for Marbank, which is responsible for the collection and preservation of MabCent's marine library.
The Tromsø scientists are extracting active molecules directly from the organisms, with the goal of obtaining between 100 g and a kilogram of material per organism. After the material is extracted and cataloged, it will be screened for molecules displaying antitumor, antibacterial, or immunomodulating properties, as well as for enzymes and enzyme-inhibiting activities.
With a lot of work ahead, MabCent expects over its eight years of funding to hire up to 35 marine biologists, chemists, biochemists, and other scientists. Hits generated by the group will be passed off to industrial partners that will conduct further pharmaceutical studies. Partners also will come up with synthetic or fermentation routes to produce them on a large scale.
One Tromsø-based firm has already seen some success based on earlier bioprospecting activities. Biotec Pharmacon has commercialized uracil-DNA glycosylase, an enzyme found in Atlantic cod, for use in polymerase chain reaction experiments.
STILL OTHERS are poised to capitalize on MabCent's biobank. Most notably, Lytix Biopharma, a Troms??-based biotech firm, has signed a licensing agreement with the university that gives it access to the molecular diversity of the biobank. The firm will take hits in certain therapeutic areas from MabCent's screens and then apply its peptide and small-molecule expertise to "add value," says Oystein Rekdal, Lytix' chief executive officer.
Although research is advancing and companies are being created, scientists in both Tromsø and Trondheim recognize that marine bioprospecting still faces challenges. For one thing, although a small cluster of oncology researchers is forming in Oslo, Norway is not known as a biotech hot spot, and support services are few and far between. Once research moves into the development stage, companies are largely reliant on contractors outside of Norway.
Also, some Norwegian researchers are frustrated that the government has not made the biotech industry more of a priority. Though the MabCent program in Tromsø has won an influx of cash from the government, funding in Trondheim has been harder to come by, and researchers are now turning to private, largely foreign, investors.
The funding situation is not helped by the inherent modesty of many Norwegian scientists, who seem content to let their marine bioprospecting efforts fly under the radar in the larger biotech community. Their lack of self-promotion may hinder their ability to attract financing and licensing partners, particularly from outside of Scandinavia.
Still, the opportunity appears to be as vast as the natural resources at the scientists' doorstep. Given their motivation, Norway's biotechnological promise may be limited only by the speed with which they can mine the country's icy waters.
- Chemical & Engineering News
- ISSN 0009-2347
- Copyright © American Chemical Society