475659 Evaluation of the Therapeutic Potential of FOXC1 Knockdown for Treatment of Basal-Like Breast Cancers
Knockdown of protein products from aberrant or overexpressed genes can be achieved by delivering repair machinery to act at the DNA level, or RNA interference machinery to elicit degradation of mRNA products of targeted genes. The CRISPR/Cas9 system is a cutting-edge method that has the ability to produce double stranded cuts in DNA at targeted locations in the eukaryotic genome in order to produce controlled deletions or insertions of genetic code. RNAi was used to knockdown FOXC1 in 4T1 cells (mouse BLBC). Knockdown (>95%) was verified via western blot and proliferation studies showed a statistically significant (p<0.013) reduction in cell growth up to 96 hours post transfection. The CRISPR/Cas9 system was used to produce clone 4T1 cells exhibiting knockout of the FOXC1 gene (verified via western blot). Clone proliferation studies in vitro showed similar results to knockdown studies. These clones were used to produce tumors in mice models that were compared to 4T1 tumors in control specimens. Knockout tumors exhibited no reduction in metastatic activity compared to controls and showed no statistical reduction in growth rate. The study indicates that therapies targeting FOXC1 are possible and even successful in vitro. However, the inherent complexity of physiological systems convolutes the effect of any positive therapeutic response in vivo.
1. Smid M, et al. Cancer Res. 2008; 68:3108-3114
2. Seewaldt VL, Scott V. N Engl J Med 2007; 356: e12
3. Sarrio D, et al. Cancer Res 2008; 68:989-997.
4. Ray P, et al. Cancer Res 2010; 70:3870-3876
See more of this Group/Topical: Pharmaceutical Discovery, Development and Manufacturing Forum