Anti-HER2/Toxin Expressing Lymphocytes for Breast Cancer Therapy

摘要

Cyclin E is a key regulator of the mammalian cell cycle, as it is rate limiting for progression from G1 to S phase. Deranged cyclin E expression has been found both quantitatively (overexpression) and qualitatively (multiple isoforms) in almost all breast cancer cell lines and patient tissue samples. In spite of the apparent significance of altered cyclin E expression, the role of cyclin E overexpression in the transformation and proliferation of breast cancer cells has not been established. Using an intrabody approach, we are developing a model to phenotypically knock out cyclin E in breast cancer cells to investigate the role cyclin E plays in the tumorigenicity of these cells. We have constructed two anti-cyclin E single-chain antibodies (sFv) and have displayed their ability to bind cyclin E by ELISA. We have successfully targeted expression of these intrabodies to the cytosol and nucleus of breast cancer cell lines (SKSR3 and MCF-7) as conjugates with the human IgG constant region fragment(sFv-Fc) . We are currently investigating the effect of anti-cyclin E intrabodies on the growth and tumorigenicity of clonal SKBR3 and MCF-7 cell lines either stably or inducibly expressing the intrabodies.