Tokyo, September 30, 2005 --- NEC Corporation today announced
that it has verified the effectiveness of a new drug screening
system, ChemMinerTM, which utilizes data mining techniques such as
active learning (note 1), enabling a ten-fold improvement in
screening performance, resulting in an approximate 90% decrease in
screening cost, as compared with conventional screening systems.
The system’s effectiveness has been verified through collaborative
research with Tanabe Seiyaku Co., Ltd, a Japanese pharmaceutical
company, to which the system will be delivered in September.
The main points of this new system are as
follows:
(1) Development of a novel technique called "exponential
selection."
At an actual screening site, detection of active compounds
(compounds that are effective for drug purposes when they interact
with protein in some form) is rare, thus discovery of active
compounds has been one of the issues with conventional screening
methods such as random screening to date. NEC’ s proprietary new
technique allows scoring of compounds by the information gained
from prior screening by low or high probability. This method aims
to detect low scored compounds with low probability to aid
selection of more informative compounds during the next stage of
experiments/screening. This method enables the finding of extremely
rare active compounds from anywhere from several hundred thousand
to several million sets of compounds.
(2) Development of a novel technique called "descriptor
sampling."
With active learning, data learned at an early stage can limit
the diversity of a system, thus new types of compounds are often
not discovered, representing another major issue of the random
screening method. With this unique technique, some descriptors are
masked and are not utilized for learning, allowing greater
diversity, which can lead to the finding of diverse groups of
compounds.
(3) Improved system performance as compared with conventional
methods:
By applying (1) and (2) to a type of G protein-coupled receptor
("GPCR" note 2), NEC was able to demonstrate improved screening
system performance as compared with conventional methods for
several data groups. The number of assay wet experiments, which are
vital to the finding of active compounds, carried out during
screening was reduced by anywhere from 88% - 97% compared to
conventional methods (note 3). This improvement achieves a
substantial reduction in screening costs by approximately 90% from
several hundred thousand to several tens of thousands of
dollars.
During the drug discovery process, systems will screen a huge
chemical library, consisting of anywhere from one hundred thousand
to one million chemical compounds, in order to search for chemical
compounds effective in drug creation. This incurs exorbitant cost
as screenings require the performing of costly wet experiments. NEC
expects this new system to respond to the need for a more
economical drug screening system, which has been long sought after
in the pharmaceutical field.
NEC’s Bio-IT Business Promotion Center will begin offering
outsourcing services for the screening of new drugs from September,
2005 and plans to begin sales of ChemMinerTM at a later date.
Notes
1) Learning method:
Learning is commonly performed with pre-prepared learning
databases. This means that all the contents of the database will be
used in learning. The learning system ‘passively’ obtains data for
learning and then proceeds to learn it. In active learning, the
learning system ‘actively’ chooses data that should be learned. The
candidate data contains only descriptors and no information about
its label. When data is chosen, its label is given based on
additional experimentation, or from prepared learning databases in
the case of computer simulation. The chosen data is accumulated to
a database for learning, and learning is performed with its entire
contents. In active learning, the system has control over which
data should be used for learning to accomplish high prediction
accuracy with a lesser number of labeled data. Acquiring labels for
compounds require expensive wet experiments in the case of drug
screening, thus a lesser number of wet experiments is
desirable.
2) GPCR:
GPCRs are a family of proteins that are major, important
screening targets in the drug discovery field. However, few
tertiary structures have yet to be revealed, limiting computer
simulation based on them.
3) Computer-based experiments:
Computer based experiments were carried out by NEC, which
contained approximately 1500 "hits" that bind to GPCR, from a
library consisting of 260,000 compounds. During the first
experiment 5000 data were learned, in which 37 hits were included.
By using NEC’s new method we were able to locate 91 percent of
these "hits" by only 12% of the cost of the conventional method,
enabling a cost reduction of 88%. With a cost reduction of 78% we
were able to locate 98 percent of the "hits". We also tested
several other groups of more challenging data, for which no "hits"
had been found during the first experiment and succeeded in finding
"hits." The number of assay wet experiments, which are vital to the
finding of active compounds, carried out during screening was
reduced by anywhere from 88% - 97% compared to conventional
methods.
About NEC Corporation
NEC Corporation (NASDAQ: NIPNY) (FTSE: 6701q.l) is one of the
world's leading providers of Internet, broadband network and
enterprise business solutions dedicated to meeting the specialized
needs of its diverse and global base of customers. Ranked as one of
the world's top patent-producing companies, NEC delivers tailored
solutions in the key fields of computer, networking and electron
devices, by integrating its technical strengths in IT and Networks,
and by providing advanced semiconductor solutions through NEC
Electronics Corporation. The NEC Group employs more than 140,000
people worldwide and had net sales of 4,855 billion yen (approx.
$45.4 billion) in the fiscal year ended March 2005.
For additional information, please visit the NEC home page
at:
http://www.nec.com
* Newsroom:
http://www.nec.co.jp/press/en/
***
NEC Press Contacts:
In Japan
Diane Foley
NEC Corporation
d-foley@ax.jp.nec.com
+81-3-3798-6511