( of effect.We anticipate selecting a le...)Kosan Presents Preclinical Data on Nuclear Export Inhibitors, Novel,Anticancer Agents, at AACR,Health

Data on Kosan's NEIs were presented in two posters at the 2007 Annual Meeting of the American Association for Cancer Research (AACR), being held in Los Angeles, CA.

    -- Abstract 5609:  "Nuclear Export Inhibitors (NEIs) as Novel Cancer

       Therapeutics" presents results from analyses of the in vitro activity

       of NEIs showing that upon the addition of low nanomolar concentrations

       of polyketide-based nuclear export inhibitors to cancer cells, the

       accumulation of CRM1-dependent cargo proteins sequestered in the

       nucleus is detected rapidly. Results also show that exposure to NEIs

       causes an increase in multiple markers of apoptosis including plasma

       membrane alterations (Annexin V binding) and caspase activation in

       cancer cells. NEI treatment induces cell cycle arrest, but not

       apoptosis, in normal cells. NEIs show potent activity as single agents

       in in vivo tumor models and may also have application in combination

       therapies as NEIs are synergistic when combined with a broad spectrum

       of cancer therapeutics in in vitro experiments.

    -- Abstract 5597:  "Anti-Tumor Activity of Novel Nuclear Export Inhibitors

       (NEIs) in Multiple Xenograft Models" presents data on two members of

       Kosan's lead NEI series which are shown to have a wide therapeutic

       window in several in vivo xenograft models, including human tumor

       xenograft models of cervical cancer, colon cancer, breast cancer,

       non-small cell lung cancer, melanoma and leukemia. Kosan's lead NEI

       analogs have a high level of tolerability and demonstrated efficacy,

       and represent potentially novel anticancer agents.

About Kosan

Kosan Biosciences is a biotechnology company advancing two new classe
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