Welcome to the world of synthetic biology, where micro-organisms can be programmed to invade and destroy cancer cells.
By SCOTT
GOTTLIEB
It once seemed that the most profound feats stemming from DNA-based science
would spring from our ability to read and detect genes, which we call the
science of genomics. But the real opportunities lie in our ability to write
DNA, to synthesize new gene sequences and insert them into organisms, resulting
in brand-new biological functions. Printing novel DNA might open the way to
achievements once only conceivable in science fiction: designer bacteria that
can produce new chemicals, such as more efficient fuels, or synthetic versions
of our cells that make us resistant to the effects of radiation.
The first such genome was made in 2000 in an experiment where scientists
synthesized their own version of the hepatitis C virus so that they could alter
it and discover a way to disable the infection. Today it is possible to read
gene sequences into computers, where we can alter them and then print a modified
gene into living cells. In "Regenesis," a book exploring the science
of synthetic biology, George Church and Ed Regis imagine a world where
micro-organisms are capable of producing clean petroleum or detecting arsenic
in drinking water, where people sport genetic modifications that render their
bodies impervious to the flu, or where a synthetic organism can be programmed
to invade and destroy cancer cells.
Mr. Church is currently a professor of genetics at the Harvard Medical
School. He arrived there after a storied career as one of the early pioneers in
the science of identifying and reading genes. With fellow scientist Walter
Gilbert, he developed the first consistent process for sequencing strands of
DNA and, in 1984, helped launch the historic project to map the entire human
genome while he was a research scientist at the then newly formed biotech
company Biogen.
"Regenesis" begins with a historical look at the evolution of
genomics, providing a primer on the science that underlies the field. The
authors then describe the ways in which different applications of synthetic
biology may transform established science and effectively make obsolete current
principles in medicine and manufacturing. Along the way, they offer a
definitive account of the advances and business ventures that define this new
science.
Mr. Church and Mr. Regis, a broadly published science writer, spend a lot
of time describing the latest industrial applications of synthetic genomics.
For example, researchers are using genetically altered cyanobacteria to convert
sunlight and carbon dioxide into alkanes, the molecular constituents of diesel
fuel. This green science isn't yet cost effective. When the Navy recently
bought 21,000 gallons of algae-derived jet fuel, it cost $424 per gallon.
(Currently, the oil-derived fuel costs around $5 per gallon.) But the ability
to alter organisms to increase their yield is growing at an exponential tempo.
And our ability to manipulate DNA sequences on microprocessors and write the
strands into living organisms is taking a similar trajectory. As the tools for
doing these things become more powerful, industrial exploitation will become
more widespread and effective.
Then there is the multiplex automated genetic engineering machine invented
by Mr. Church and three colleagues from Harvard. This tool makes the process of
synthesizing new genes much faster. One of the most promising, although
controversial, applications is to re-engineer the human genome itself "for
the purpose of preventing many diseases from occurring in the first
place." The tool holds great promise. Imagine if we could remove from our
genomes the "host machinery" that viruses need to replicate,
potentially making us immune to illnesses as ordinary as the flu.
Such developments promise a great deal, but they also make people
uncomfortable and prompt calls for limits on what scientists are allowed to do.
But recent history suggests that, when new scientific developments have created
theoretical risks, scientists themselves have come together to set boundaries
on their work until any uncertainties can be better understood and resolved.
The self-imposed limits have also made sure that new science wasn't used in
dangerous or untoward ways. When there were concerns about recombinant DNA in
the early days of synthetic biology, for example, researchers imposed a
moratorium until the risks could be contained. When gene therapy was believed
to harbor latent risks, research was largely put on hold until the risks were
better understood. Sometimes, the theoretical risks have led to a principle of
absolutist precaution that impedes progress. Today the Food and Drug Administration
so tightly regulates gene therapy that few new ventures go forward. But,
Messrs. Church and Regis argue, the practical promise of a technology will
ultimately prevail. "The industrial revolution that the Luddites tried to
prevent in 1811 has brought us enormous benefits," they write.
The more elusive problem isn't safety but security—"preventing the
deliberate misuse of engineered organisms," as the authors define the
concept. DNA synthesizers are small, cheap and easy to procure. The technical
means for harnessing these tools is relatively straightforward—within the grasp
of scientists of modest training. The instruction sets are also easily found on
the Internet. Rogue regimes and lone villains could one day exploit these
scientific methods for diabolical aims. Such a security breach could play like
the plot of the 1995 hit film "Twelve Monkeys," where a wicked
scientist engineers a virus that nearly drives mankind to extinction. With the
advent of what the authors call "garage biology," Messrs. Church and
Regis think, such scenarios are no longer wildly implausible. "In the end,
we found no magic bullets for absolutely preventing worst-case scenarios, no
fail-safe fail-safes."
No comments:
Post a Comment