Beyond laser microdissection technology: follow the yellow brick road for cancer research.

Normal biological tissues harbour different populations of cells with intricate spacial distribution patterns resulting in heterogeneity of their overall cellular composition. Laser microdissection involving direct viewing and expertise by a pathologist, enables access to defined cell populations or specific region on any type of tissue sample, thus selecting near-pure populations of targeted cells. It opens the way for molecular methods directed towards well-defined populations, and provides also a powerful tool in studies focused on a limited number of cells. Laser microdissection has wide applications in oncology (diagnosis and research), cellular and molecular biology, biochemistry and forensics for tissue selection, but other areas have been gradually opened up to these new methodological approaches, such as cell cultures and cytogenetics. In clinical oncology trials, molecular profiling of microdissected samples can yield global "omics" information which, together, with the morphological analysis of cells, can provide the basis for diagnosis, prognosis and patient-tailored treatments. This remarkable technology has brought new insights in the understanding of DNA, RNA, and the biological functions and regulation of proteins to identify molecular disease signatures. We review herein the different applications of laser microdissection in a variety of fields, and we particularly focus attention on the pre-analytical steps that are crucial to successfully perform molecular-level investigations.