A human pancreatic adenocarcinoma lambda gt11 expression library was differentially screened with mRNA derived from normal and cancerous pancreatic tissues. Five clones preferentially hybridized with pancreatic adenocarcinoma mRNA. cDNA inserts from 4 of these clones were amplified by PCR, labelled with alpha 32P and used in Northern blot analysis against mRNA prepared from a variety of tumour and normal tissues. lambda GER-4 identified a pancreas-associated mRNA (greater than 10 kb) with no homology with known sequences at either the nucleic or amino-acid level. lambda GER-2 identified a 1.7-kb mRNA transcript that was over-expressed in mRNA prepared from pancreas, colon, breast, lung and gastric tumours relative to normal tissues. Sequence analysis and restriction-enzyme mapping showed that this clone was completely homologous with the active form of human elongation factor EF-1 alpha. This high level of EF-1 alpha-mRNA expression in tumour tissues lends support to the increasing evidence that EF-1 alpha is an important regulator of the cell cycle.

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