Molecular cytogenetic analysis of two primary squamous cell carcinomas of the lung using multicolor fluorescence in situ hybridization

To fully characterize the numerous chromosomal aberrations in two human squamous cell carcinomas (SCCs) of the lung, molecular cytogenetic characterization was carried out utilizing conventional banding analysis and multicolor fluorescence in situ hybridization (mFISH), providing simultaneous color discrimination of all 24 human chromosomes. Both tumors displayed complex aneuploid karyotypes with a host of numerical and structural chromosome abnormalities. Structural aberrations common to both SCCs included rearrangements of chromosomes 1, 3p, 7q, and 8q, contributing to net loss of chromosomal sequences on lp, 3p, and 8p, and a net gain of 8q. The recently introduced mFISH technique enabled the disclosure of cryptic translocations and the chromosomal composition of previously unrecognized marker chromosomes. Furthermore, mFISH greatly enhanced the ability to delineate chromosomal breakpoints when integrating banding information from conventional banding analysis. Eventually, the application of mFISH as a powerful approach to refine complex tumor karyotypes is expected to result in a more detailed and complete picture of cytogenetic events associated with the development and progression of solid tumors.