Mouse Anti-Human Centromere Protein B (CENP-B) Hybridoma [3E-8]

The oncogenic transcription factor forkhead box Ml (FoxMl) is overexpressed in a number of different carcinomas, whereas its expression is turned off in terminally differentiated cells. For this reason, FoxMl is an attractive target for therapeutic intervention in cancer treatment. As a first step toward realizing this goal, in this study, using a high-throughput, cell-based assay system, we screened for and isolated the antibiotic thiazole compound Siomycin A as an inhibitor of FoxMl. Interestingly, we observed that Siomycin A was able to down-regulate the transcriptional activity as well as the protein and mRNA abundance of FoxMl. Consequently, we found that the downstream target genes of FoxMl, such as Cdc25B, Sarvivin, and CENPB, were repressed. Also, we observed that consistent with earlier reports of FoxMl inhibition, Siomycin A was able to reduce anchorage-independent growth of cells in soft agar. Furthermore, we found that Siomycin A was able to induce apoptosis selectively in transformed but not normal cells of the same origin. Taken together, our data suggest that FoxMl inhibitor Siomycin A could represent a useful starting point for the development of anticancer therapeutics.

Plant genome engineering as a practical matter will require stable introduction of long and complex segments of DNA sequence into plant genomes. Here we show that it is possible to synthetically engineer and introduce centromere-sized satellite repeat arrays into maize. We designed a synthetic repeat monomer of 156 bp that contains five DNA-binding motifs (LacO, TetO, Gal4, LexA, and CENPB), and extended it into tandem arrays using an overlapping PCR method similar to that commonly used in gene synthesis. The PCR products were then directly transformed into maize using biolistic transformation. We identified three resulting insertion sites (arrayed binding sites), the longest of which is at least 1100 kb. The LacI DNA-binding module is sufficient to efficiently tether YFP to the arrayed binding sites. We conclude that synthetic repeats can be delivered into plant cells by omitting passage through Escherichia coli, that they generally insert into one locus, and that great lengths may be achieved. It is anticipated that these experimental approaches will be useful for future applications in artificial chromosome design.