The ZytoLight ® SPEC KIF5B Dual Color Break Apart Probe is designed to detect translocations involving the chromosomal region 10p11.22 harboring the KIF5B (kinesin family member 5B) gene. About 5% of all non-small cell lung cancer cases are positive for the ALK-EML4 fusion as a result of an inversion in chromosome 2. However, not in all cases showing an aberration of the ALK gene the EML4-ALK fusion transcript could be detected. KIF5B was identified as a novel fusion partner for ALK in ALK-positive lung cancer. KIF5B is a ubiquitously expressed microtubulebased motor protein involved in organelle transport. The translocation t(2;10) (p23;p11.2) results in the fusion of the first domains of KIF5B including the motor domain and the coiled-coil domain with the tyrosine kinase domain of ALK. Overexpression of the aberrant KIF5B/ALK fusion transcript can lead to enhanced cell proliferation, migration, and invasion. A further aberration affecting the KIF5B gene is inv(10)(p11.2q11.2). This inversion was detected in adenocarcinomas of the lung and results in the fusion of KIF5B with the ret proto-oncogene (RET). The fusion transcript again comprises the coiledcoil domain of KIF5B and the tyrosine kinase domain of RET. In accordance with the EML4-ALK fusion the development of specific agents targeting KIF5B-RET might provide a new therapeutic strategy for lung adenocarcinomas.
