Molecular events involved in the neoplastic transformation of Barrett’s mucosa and their potential clinical use
| Events | Type of change, comment | Diagnostic use |
|---|---|---|
| Increased proliferation by | ||
| immunohistochemistry | Ki67 expression at the surface in HGD | ++ |
| flow cytometry | Increased G2-M phase | + |
| Cell cycle regulators | ||
| p16 (CDKN2A) | Early LOH, late hypermethylation of 2nd allele | − |
| cyclins D1 and E | Increased expression in cancer | − |
| growth factors (GF) and GF receptors | ||
| TGFα, EGF | Increased expression in cancer | − |
| EGFR | Frequent amplification in cancer | − |
| c-erbB2 | Less common overexpression as EGFR | − |
| Tumour suppressor genes | ||
| p53 | Frequent mutation in HGD and cancer | ++ |
| APC | Early LOH and promoter methylation | − |
| Rb | Uncommon direct implication | − |
| Cell adhesion | ||
| E-cadherin | Decreased expression in cancer | +/− |
| β catenin | Decreased expression and nuclear shift | +/− |
| COX-2 | Increased expression, results in increased angiogenesis and decreased apoptosis | ? |
| Telomerase | Increased expression parallel to dysplasia | − |
| DNA ploidy | Early DNA aneuploidy | + |
| Bcl2/bax | Disturbed balance | ? |
| Microsatellite instability | Very uncommon in cancer | − |