US Researcher Couple Hope Abandoned Mine Could Hold the Key to Cancer Treatment

by Gopalan on Sep 24 2007 2:17 PM

The Berkeley Pit lake, in Butte, Montana, US holds 37 billion gallons of deadly poison. It is a lake formed in an abandoned copper mine. It is a toxic teardrop in the middle of a Montana wasteland. No fish live in the lake; no grass, reeds, or bushes grow along its fenced-off shores. Not even a mosquito buzzes through the air.

Still two adventurous researchers at the Montana Tech, Don and Andrea Stierle, have been engaged in the extremely risky task of discovering drugs from out of the toxic dump. They have so far identified more than 100 types of microbes in the lake and which could hold a key to cancer treatment.

The microbes have yielded more than 50 different compounds that the Stierles have isolated and tested against enzymes present in diseased human tissue. An extract from a newly discovered species of Penicillium from the lake attacked ovarian cancer cells in lab tests. Another Berkeley Pit Penicillium shows promise in treating lung tumors.

Extremophiles of Berkeley Pit, creatures that can survive an impossibly harsh environment, have obviously evolved biological tricks to help them get by. These tricks can be useful to humans, the Steireles figure.

Bacteria living in hot springs produce a heat- tolerant enzyme that researchers use for polymerase chain reaction, a high- temperature lab technique that amplifies tiny amounts of DNA into a larger sample.

Today, the Stierles grow their microbes in petri dishes and flasks arranged about their two-room lab and they wait for the microbes to produce chemical products and then extract and purify them — all by hand.

Once they have a microbial extract, they test it against an enzyme produced by tumor cells. If the extract blocks enzymatic activity, they send it to the National Institute of Health (NIH) to be tested against a 60-cell-line screen maintained by the National Cancer Institute, living samples from eight different solid tumor cancers.

Their first big hit, berkeleydione, came from a Penicillium species they found in a pit-water sample in 1998. It inhibited the growth of non-small cell lung cancer. That gave them enough credibility to keep at it. Then, in 2002, they found a Penicillium species that, like berkeleydione, was unique to Berkeley Pit. A compound it made worked against the enzymes in their assay kit and in the NCI 60-cell assay, where an extract from the stuff attacked cells from OVCAR-3, an ovarian cancer. "With the first compound, the reaction was like, ‘Well, OK, that's interesting,'" Andrea says. "But when we did it again, it was, ‘Wow! Maybe there's more to these pit microbes than we thought.'"

But the Stierles have no idea whether anything they find will actually lead to a medicine. "What you wait for is a partner," Andrea says. "We don't have a big enough lab to do large-scale fermentation.”

Who will replicate then the Stierles' findings on a large scale. Then there will be the trials — on enzymes and animals first, and perhaps eventually on people. Is it safe? Does it do what the Stierles' work suggests that it might? The Stierles have neither the infrastructure nor the money to even begin this process.

They are keeping their fingers crossed.