| Abstract: | BACKGROUND: Our previous studies showed that top-ical 5-aminolevulinic acid-mediated photodynamic ther-apy (ALA-PDT) is very effective for oral verrucoushyperplasia (OVH) and relatively less effective for oralleukoplakia (OL) lesions. Nevertheless, there has been noreport on the association of the expression of apoptosis-related proteins in OVH and OL biopsy tissues prior toPDT with PDT treatment outcomes.METHODS: This study used immunohistochemistry toevaluate whether the expression of Bak, Mcl-1, caspase-3,caspase-8, caspase-9, p53, p21, or PCNA protein in biopsyspecimens of OVH and OL lesions could be used to predictthe clinical outcomes of 18 OVH and 40 OL lesions treatedwith topical ALA-PDT. The marker labeling score (LS) wasdefined as labeling index (positive cells/total cells) multi-plied by staining intensity. The lesions after ALA-PDTtreatment were divided into complete response (CR)group and partial or no response (PR/NR) group.RESULTS: The mean Bak LS and the mean Bak/Mcl-1 LSratio were significantly higher in the CR group than in thePR/NR group. However, there was no significant differencein the Mcl-1, caspase-3, caspase-8, caspase-9, p53, p21, orPCNA protein LS between the CR and PR/NR groups.CONCLUSION: We conclude that the Bak LS or Bak/Mcl-1 LS ratio may be a useful biomarker to predict theclinical outcomes of OVH and OL lesions treated withtopical ALA-PDT. Pre-PDT epithelial cell levels of Mcl-1,caspase-3, caspase-8, caspase-9, p53, p21, and PCNA maynot have a significant influence on the clinical outcome ofOVH and OL lesions treated with topical ALA-PDT. |
