PAF RECEPTOR GENE ISOLATEDJapanese researchers report in today's issue of Nature that theyidentified a key component in the development of targeteddrugs to treat asthma, septic shock and other inflammatorydiseases.

Zen-ichiro Hondo and colleagues at Tokyo University describethe first isolation of a gene encoding a receptor for plateletactivating factor. PAF is one of a group of phospholipids thatare potent inflammatory agents. Others are prostaglandins andleukotrienes.

The inability to isolate PAF receptors has hampereddevelopment of drugs that block PAF's inflammatory actions.Companies developing such drugs include British BiotechnologyGroup plc, Nippon Boehringer Ingelheim Co., SumitomoPharmaceutical Co., Takeda Chemical Industries Ltd.,Yamanouchi Pharmaceutical Co. and Yoshitomi PharmaceuticalIndustries Ltd.

Today's report represents the first cloning of a receptor for aphospholipid molecule. The gene was isolated from a guinea piglung cDNA library.

"The cloning of a PAF-receptor cDNA opens up new avenues ofresearch," said Dr. Peter J. Barnes of the National Heart andLung Institute in London. Understanding the receptor'sstructure and function aids the design of drugs to block PAF'sinflammatory effects. -- Carol Talkington Verser, Ph.D.

CHROMOSOMES SUPPRESS CARCINOMA GROWTH

Human chromosomes 5 and 18 contain tumor suppressor genesthat can reduce colon carcinoma cell growth, according to anarticle in today's issue of Nature. Researchers from The TokyoMetropolitan Institute of Medical Science and TottoriUniversity in Yonago, Japan, introduced individual humanchromosomes into human colon cancer cells. Hybrid cells thatreceived either human chromosome 5 (C-5) or 18 (C-18) didnot grow into tumors when they were transplanted into amouse model. But hybrid cells that received humanchromosome 11 were still able to form tumors in the mousemodel.

Applied bioTechnology Inc., Oncor Inc. and Oncogene ScienceInc. are already developing cancer diagnostics and therapeuticsbased on other genes that scientists have already identified ashaving tumor suppressor characteristics. Scientists haveidentified the APC gene on C-5 and the DCC gene on C-8 aspotential tumor suppressor genes. The results reported todaydo not test these genes specifically, but do show that thechromosomes containing these genes suppress cancer growth.

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