Fig. 5. Enhanced p53 and cleaved Caspase-3 expression is shown in clinical PV patient samples and also in keratinocyte cultures treated with PV sera.

p53 a and cleaved Caspase-3 b immunohistochemistry in oral mucous tissues from PV patients. Significantly enhanced p53 staining was detected in 48% of patients (arrowheads indicate positive nuclear staining whereas arrows indicate predominant cytoplasmic staining), compared to normal controls. Oral mucous cancer was used as positive control here. Asterisks indicate the areas of the blisters. Positive staining of active caspase-3 was also detected in PV patients with the positive p53 staining in oral mucous tissues, especially in the basal and immediate suprabasal layers of stratified squamous epithelium. The positive staining was also detected in cells located in sub-mucous connective tissue (right)