AGRO100

AGRO100, an experimental anticancer drug that recently entered human clinical trials, is a member of a novel class of antiproliferative agents known as G-rich oligonucleotides (GRO), which are non-antisense, guanosine-rich phosphodiester oligodeoxynucleotides that form stable G-quadruplex structures. The biological activity of GROs results from their binding to specific cellular proteins as aptamers. One important target protein of GROs has been previously identified as nucleolin, a multifunctional protein expressed at high levels by cancer cells. AGRO100 also associates with nuclear factor-{kappa}B (NF-{kappa}B) essential modulator (NEMO), which is a regulatory subunit of the inhibitor of {kappa}B (I{kappa}B) kinase (IKK) complex, and also called IKK{gamma}. In the classic NF-{kappa}B pathway, the IKK complex is required for phosphorylation of I{kappa}B{alpha} and subsequent activation of the transcription factor NF-{kappa}B. Research shows that treatment of cancer cells with AGRO100 inhibits IKK activity and reduces phosphorylation of I{kappa}B{alpha} in response to tumor necrosis factor-{alpha} stimulation. It also shows that AGRO100 blocks both tumor necrosis factor-{alpha}-induced and constitutive NF-{kappa}B activity in human cancer cell lines derived from cervical, prostate, breast, and lung carcinomas. In addition, in AGRO100-treated cancer cells, NEMO is coprecipitated by nucleolin, indicating that both proteins are present in the same complex. Studies suggest that abrogation of NF-{kappa}B activity may contribute to the anticancer effects of AGRO100 and that nucleolin may play a previously unknown role in regulating the NF-{kappa}B pathway. [PubMed: 16891465]