Abstract: A method for balancing multiplexed PCR methods is provided. In the method, two or more sequential temporal PCR stages are used to effectively separate two or more PCR reactions in a single tube as an alternative to primer limiting to modulate the relative rate of production of a first amplicon by a first primer set and a second amplicon by a second primer set during the first and second amplification stages. Also provided are rapid RT-PCR methods that find particular use in intraoperative diagnoses and prognoses, for instance in diagnosing malignant esophageal adenocarcenoma by determining expression levels of carcinoembryonic antigen (CEA) in sentinel lymph nodes.

Abstract: The c-Myc oncoprotein, a helix-loop-helix-leucine zipper (HLH-ZIP) transcription factor, is frequently deregulated in human cancers. All known functions of c-Myc, including those pertaining to transformation, require that it heterodimerize with another HLH-ZIP protein, Max. Using a high throughput yeast-based assay, we identified seven low molecular weight substances that inhibit c-Myc-Max association. Each compound also prevented this interaction in vitro and inhibited the growth of c-Myc-expressing fibroblasts, although not of fibroblasts lacking c-Myc. Finally, short-term exposure of c-Myc over expressing fibroblasts to several of the compounds markedly reduced their in vivo tumorigenicity. These studies suggest that yeast-based assays can be used to identify inhibitors of protein-protein interactions and that these frequently function in mammalian cells. The signature specificities of each of the c-Myc-Max compounds identified here further suggest synergistic in vivo function.