Identification of a 170-kDa protein over-expressed in lung cancers

Lung cancer is the leading cause for cancer death in both male and female p opulations. Although many molecular markers for lung cancer have been devel oped and useful for early detection of lung cancer, their function remains unknown. In this paper, we report our findings that a 170-kDa protein (p170 ) is over-expressed in ail types of human lung cancers compared with normal tissues and it is identified as a subunit of translation initiation factor elF3 by cDNA cloning, Translation initiation factors are a family of prote ins that promote the initiation step of protein synthesis and are regulator s of cell growth at the translational level. Further studies showed that p1 70 mRNA is ubiquitously expressed with higher levels in adult proliferating tissues (e.g. bone marrow) and tissues during development (e.g. fetal tiss ues), This study suggests that p170 and elF3 may be important factors for c ell growth, development, and tumorigenesis. (C) 2001 Cancer Research Campai gn.