Chromosome Microdissection

It has been known for decades that chromosome rearrangements exist in most if not all human tumors (1 ) and certain human hereditary diseases (2 ). Distinct chromosomal abnormalities in tumors lead to the activation of proto oncogene products, creation of tumor specific fusion proteins, or inactivation of tumor suppressor genes. Since chromosome banding techniques were developed, cytogenetic study of nonrandom chromosome abnormalities in malignant cells has become an integral part of the diagnostic and prognostic work up of many human cancers (3 ). However, not all cytogenetically visible chromosome rearrangements (e.g., complex chromosome rearrangements, small ring chromosomes, and unidentifiable de novo unbalanced translocation) can be determined by conventional cytogenetic banding analysis. This technique limitation prevents complete karyotypic analysis in many human cancers, particularly solid tumors. This technical limitation has been complemented by the combined use of chromosome microdissection and fluorescence in situ hybridization (FISH) techniques (4 ). Chromosome microdissection has been developed as a very powerful tool to proceed rapidly from cytogenetic observation to molecular analysis.