Topical tacrolimus has a limited direct effect on ultraviolet B-irradiated keratinocytes: implications for its photocarcinogenic potential.

Abstract

BACKGROUND:

Topical tacrolimus has shown remarkable clinical efficacy in treating many dermatoses. Combining ultraviolet (UV) B and tacrolimus is an intriguing therapeutic regimen, especially for treatment of vitiligo, for which combination therapy may show greater clinical efficacy than topical tacrolimus alone. The photocarcinogenic potential of such a regimen is unclear, and conflicting results have been reported by different investigators.

AIM:

To clarify this important clinical issue, we investigated the effects of tacrolimus on UVB-irradiated cultured keratinocytes in terms of apoptosis, differentiation, cell-cycle regulation and DNA damage.

METHODS:

Cultured keratinocytes were treated with tacrolimus before and after UVB irradiation and the various cellular physiological changes were evaluated using trypan blue exclusion, terminal dUTP nick-end labelling, flow cytometry and Western blotting analyses.

RESULTS:

Our results showed that treatment of tacrolimus before or after UVB irradiation had no significant effects on cultured keratinocytes in terms of cell apoptosis, transglutaminase-1, involucrin expression, cell-cycle progression and phospho-H(2)AX compared with UVB irradiation alone.

CONCLUSION:

The direct effect of tacrolimus on UVB-irradiated keratinocytes is small, suggesting that clinical regimens combining UVB and tacrolimus also have a limited direct effect on healthy skin compared with UVB irradiation alone.

• Authors: C-C E Lan, H-S Yu, S-M Huang, C-S Wu, H-Y Kuo, C-H Lee, C-S Lin, G-S Chen
• Journal: Clinical and experimental dermatology (Clin Exp Dermatol) Vol. 35 Issue 2 Pg. 173-9 (Mar 2010) ISSN: 1365-2230 [Electronic] England
• PMID: 19489860 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Dermatologic Agents
• Tacrolimus

Topics

• Administration, Topical
• Apoptosis (drug effects, radiation effects)
• Cells, Cultured
• Dermatologic Agents (administration & dosage)
• Humans
• Keratinocytes (drug effects, radiation effects)
• Statistics as Topic
• Tacrolimus (administration & dosage)
• Ultraviolet Rays