Global gene expression profiling studies conducted over the last couple of years have shown that molecular profiling of breast cancers can be used to identify clinically and genetically significant subtypes of breast carcinomas and subgroups of patients with different prognosis or disease outcome, and to predict therapeutic response to both endocrine and chemotherapeutic drugs. We studied one particularly aggressive form of locally advanced breast cancer, namely inflammatory breast cancer (IBC) using cDNA micro-arrays. We demonstrated that IBC is characterized by a different gene expression profile, not related to any of the previously identified breast cancer subtypes. This gene expression profile revealed potential therapeutic targets, such as the transcription factor NF-κB. Gene expression analysis using cDNA microarrays is a technique to simultaneously analyze the expression of thousands of genes. cDNA fragments of these genes are present in spots at the surface of a glass slide. These cDNA fragments will bind to fluorescently labeled RNA molecules during hybridization. Hence, the spot containing the hybridized RNA molecules will produce a fluorescent signal proportional to the amount of RNA molecules present in sample. This fluorescent signal is a measure for gene expression. Using cDNA microarrays, complex patterns of gene expression can be deciphered.
