Tight junction protein zo-2 is differentially expressed in normal pancreatic ducts compared to human pancreatic adenocarcinoma
✍ Scribed by Alexandre Chlenski; Kathleen V. Ketels; Ming-Sound Tsao; Mark S. Talamonti; Marla R. Anderson; Ryoichi Oyasu; Dante G. Scarpelli
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- French
- Weight
- 231 KB
- Volume
- 82
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
Differential display of hamster mRNA identified a fragment present in normal pancreatic duct cells that is not expressed in pancreatic duct carcinoma cells. Sequence analysis showed an 88% and 82% identity, respectively, to the cDNA of the canine and human tight junction zo-2 gene. Semi-quantitative RT-PCR analysis of human ZO-2 revealed a striking difference in the expression of various regions of the ZO-2 transcript in normal and neoplastic cells and the presence of an abnormality at the 5Ј-end of mRNA. RACE analysis identified 2 human ZO-2 mRNAs that encode proteins of different lengths, designated as ZO-2A and ZO-2C. The difference between the 2 forms of ZO-2 is the absence of 23 amino acid residues at the N terminus of ZO-2C compared with ZO-2A. Although ZO-2C was expressed in normal pancreatic cells and a majority of neoplastic tissues analyzed, ZO-2A was undetectable except in one case in all of the pancreatic adenocarcinomas analyzed. This suggests the presence of a yet to be identified motif important for cell-growth regulation within the 23-amino acid residue N-terminal peptide of ZO-2A, MPVRGDRGFPPRRELSGWLRAPG.