Several studies have demonstrated the overexpression of certain eukaryotic translation factors in human
cancer cell lines and in malignant tissues. In this study, with human
cancer cell lines derived from lungs, breast, prostate, and skin, we have examined the expression profile of 36 translation factors consisting of 27
initiation factors, 8 elongation factors, and 1 termination factor. Translation
initiation factors 2C2 and 4E1 and translation elongation factors 1A2 and 1delta were found overexpressed (2- to 2000-fold) in many of the
cancer cell lines compared to their corresponding normal cell lines. Among the translation factors analyzed, translation
elongation factor 1A2 exhibited the most significant alteration in expression: 10- to 2000-fold overexpression was noticed in nine out of ten
cancer cell lines analyzed. Whether the overexpression of translation
elongation factor 1A2 can be used as a potential
tumor marker was tested with the
cancer profiling array (BD Biosciences, Palo Alto, CA) consisting of 241 paired
cDNA samples generated from 13 different
cancer/noncancer tissue types. Overexpression of translation
elongation factor 1A2 was noticed in several
tumor tissue samples, most notably in the human
colon cancer samples which exhibited at least a twofold overexpression among 35% of the samples analyzed. Besides colon,
tumor samples derived from lungs, kidney, rectum, and ovary also exhibited more than a twofold overexpression of translation
elongation factor 1A2 in at least 20% of the samples analyzed. These results indicate that human
carcinogenesis is often associated with alterations in the expression of various translation factors especially the overexpression of eukaryotic translation
elongation factor 1A2.