The ubiquitin-activating enzyme E1-like protein in lung cancer cell lines

The UBEIL gene isolated from the chromosome 3p21 region has an extremely re duced level of mRNA in lung cancer. Sequence analysis showed a 45% homology to the human ubiquitin-activating enzyme El at the amino acid level. To fu rther characterize the protein product, we generated UBEIL protein-specific antibodies. Immunoblot analysis revealed a full-length gene product of app roximately 112 kDa. Assessment of the level and distribution pattern of the UBEIL protein in normal and tumor tissue using the generated antibodies sh owed that the UBEIL protein was present in normal lung cells and non-lung c ancer cell lines, but was undetectable in all 14 human lung cancer cell lin es analyzed. This difference in expression of the UBEIL protein between nor mal lung tissue and lung tumor-derived cell lines suggests a possible invol vement of an El-like protein in the origin and/or progression of lung tumor s. (C) 2000 Wiley-Liss, Inc.