Taken together this study broadens our understanding about the mechanism of action of PUVA providing possible new strategy targeting proapoptotic function of RIG-1, a regulator of innate immune response or p53 for psoriasis therapy.
PASI significantly decreased after GR (P < 0.001), confirming the excellent efficacy of the treatment, However, significant increases in level of p53 protein (P < 0.05) and CA (P < 0.001) after treatment indicates that this method carries an increased genotoxic risk in patients with psoriasis.
Subsequent immunostaining of full mounted sections examined 11 BD, 7 AK, and 4 examples of psoriasis for MIB-1 (as a proliferative marker) and p53 (as a cell cycle regulatory marker).
The present data show a different regulation of TAp63 in psoriasis, where the discrepancy between mRNA levels and protein expression indicates a post-transcriptional regulation analogous to that seen in p53.
We therefore performed DNA mutational analysis of the tumor suppressor gene p53 (exons in psoralen + ultraviolet A keratoses from 10 long-term psoralen + ultraviolet A-treated psoriasis patients.
These results suggest that (i) the major initiator of p53 mutations in basal cell carcinoma in psoralen and ultraviolet A-treated psoriasis patients is environmental and/or therapeutic ultraviolet(B) exposure, and that (ii) psoralen and ultraviolet A itself causes only a smaller portion of p53 mutations in psoralen and ultraviolet A-associated basal cell carcinomas.
Our experiments, however, cannot determine whether the abnormalities of p21WAF1/CIP1 epidermal expression in psoriasis and after insult are independent of changes in p53 expression.
The purpose of this study was to investigate and to compare, by in situ hybridization, gene expression of IL-1 beta, IL-8, TGF-beta 1, TGF-beta 2, TGF-beta 3, TGF-alpha, p53 and c-myc in lesions and in non-involved skin of patients with psoriasis.