Elevated levels of eukaryotic translation initiation factor eIF-4E, mRNA in a broad spectrum of transformed cell lines

Translation initiation factor eIF-4E, which binds to the 5′ cap structure of eukaryotic mRNAs, is believed to play an important role in the control of cell growth. Over-expression of eIF-4E in fibroblasts results in their malignant transformation. However, no information on eIF-4E expression in established transformed cell lines has been available. We report here that a variety of tumor cell lines, chemically, virally and oncogenically transformed, exhibit elevated levels of eIF-4E mRNA expression as compared to their normal counterparts. Overexpression of eIF-4E, which is normally rate-limiting in protein synthesis, may stimulate the translation of regulatory and oncogenic proteins involved in transformation.