Headlines last spring touted promising cancer-fighting compounds that killed tumors in mice. Yet many hurdles lay between that promise and realizing their human potential.

One challenge is producing enough of the compounds for human tests.

University of Nebraska researchers gave one of these compounds, Endostatin™ protein, an early production boost. NU's Biological Process Development Facility team helped develop the fermentation process to make Endostatin™ protein, said Mike Meagher, Institute of Agriculture and Natural Resources bioprocess/biochemical engineer and team leader.

Endostatin™ protein, a fragment of collagen found in the body, inhibited cancerous tumor growth in mice studies. Endostatin™ blocked blood supply to mouse tumors, which shrank and disappeared. There's no guarantee of success in humans, but researchers are eager to find out. Early human trials for Endostatin™ are planned later this year. Assessing its human potential may take several years.

EntreMed Inc., the Rockville, Md., company developing Endostatin™, contracted with Meagher's team for fermentation development assistance.

"Fermentation processing is the first step in making a therapeutic protein," Meagher explained. "Basically, our job was to work with the genetically engineered material and bank of scientific data that EntreMed scientists had created and figure out how to produce more Endostatin™."

EntreMed scientists had inserted the Endostatin™ gene into Pichia pastorisyeast, which Meagher's team used to develop a fermentation recipe for producing larger batches.

Pichia pastorisfermentation is the NU team's specialty. The yeast is the workhorse for making the recombinant protein. "Pichia pastorisis just a system we can use to express, or produce, recombinant proteins such as Endostatin™," Meagher explained. Under the right fermentation conditions, recombinant yeast containing genes for a desired protein grows and makes that protein. After fermentation, the desired protein is separated from cells and other compounds.

Meagher's team works with all sorts of recombinant proteins, but each is different. The challenge is finding the best conditions for producing each protein and assuring a consistent, reproducible, reliable process.

"We have to figure out the optimum conditions to trick the Pichia into making the protein we need," he said. "You have to understand the organism and how it behaves."

Meagher's team first develops a small-scale process, boosts efficiency and refines it for larger-scale processing. Researchers document every production step and prepare instructions clients can follow in their own operations.

"On any project, we have to develop a process that's industrially robust," Meagher explained. "I've got to be able to give the process to somebody and they've got to be able to do it right the first time."

The team began its Endostatin™ work in January 1998 and finished in December. It produced Endostatin™ protein for some of EntreMed's early preclinical trials and provided fermentation processing documentation on which EntreMed could build for future GMP (Good Manufacturing Practices) production, a standard required for material used in humans.

Meagher is pleased NU has the expertise to aid development of potentially beneficial drugs, but pointed out his operation's ongoing role.

"My long-term goal is to see more biotechnology companies coming to Nebraska," he said. "I think that's doable, especially if they realize we're also educating a workforce for them."

Biotechnology companies, especially small operations, could benefit from having such facilities nearby.

"Helping small companies is part of the reason we're here," Meagher said.

Education is another.

"We hire as many students as possible bcause companies look for people with this sort of training," he said. Twelve NU undergraduate and three to four graduate students work in the operation's labs and pilot plants.

EntreMed funded the Endostatin™ work. Nebraska Research Initiative funds help support the Biological Process Development Facility, which is an NU Center for Biotechnology core facility.

- Vicki Miller

Mike Meagher, IANR bioprocess/biochemical engineer, checks a fermentation batch being processed in a bench-scale fermentor in a lab at the NU Biological Process Development Facility. The biological process development team provides protein fermentation, recovery and purification services to academic and industrial clients.

This test tube holds a small sample of Pichia pastoris yeast. Pichia pastoris fermentation is the NU team's specialty. The yeast is the workhorse for making recombinant proteins.