ELEVATED LEVELS OF EUKARYOTIC TRANSLATION INITIATION-FACTOR EIF-4E, MESSENGER-RNA IN A BROAD-SPECTRUM OF TRANSFORMED-CELL LINES

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