Effects of narrow‐band ultraviolet B and tazarotene therapy on keratinocyte proliferation and TIG3 expression

Abstract

Tazarotene plus narrow-band ultraviolet B (NB-UVB) therapy has been shown to enhance the efficacy in treating patients with psoriasis, while the mechanism is not clear. The present study aims to investigate the alteration of cell proliferation and TIG3 in cultured normal human keratinocytes after NB-UVB and/or tazarotene treatment. Keratinocytes were exposed to NB-UVB, then incubated with or without tazarotene, and then cell proliferation was detected by methyl thiazoleterazolium colorimetric assay and TIG3 mRNA expression and protein production was examined by real-time reverse transcription polymerase chain reaction and immunocytochemistry, respectively. The results show that keratinocyte proliferation was inhibited and TIG3 mRNA expression and protein production were elevated by tazarotene at a dose higher than 0.1 micromol/L. In NB-UVB single irradiating groups, only 200 mJ/cm2 NB-UVB inhibited keratinocyte proliferation, and none of the irradiated groups had an effect on TIG3 expression. Moreover, tazarotene plus NB-UVB have stronger effects than those separately. These results indicate NB-UVB plus tazarotene may have synergistic effects on inhibiting keratinocyte proliferation and elevating TIG3 expression, which may have some implications for the understanding of how to treat psoriasis patients with tazarotene plus NB-UVB.

Standardization of regimens in Narrowband UVB and PUVA in early stage mycosis fungoides: position paper from the Italian Task Force for Cutaneous Lymphomas

“…Up to 90% of UVB radiation is absorbed at most superficial epidermal layers of the skin, where exerts multiple biological activities on all cell populations. 11 In fact, despite UVB-based phototherapy surely induces apoptosis of infiltrating lymphocytes, 12 the fact that the large majority of cells in epidermis are keratinocytes, and the demonstrated activity of NB-UVB on keratinocytes, both in term of growth rate inhibition and induction of apoptosis [12][13][14][15][16][17][18] suggest that keratinocytes' modulation may play an important, if not even pivotal, role in its therapeutic effects. Furthermore, both NB and BB-UVB are able to induce, with different efficacy, Langerhans cell migration and subsequent reduction in their tissue density.…”

Ultraviolet radiation and skin mast cells: Effects, mechanisms and relevance for skin diseases

“…The effects of UVR on the skin include reddening, sunburn and tanning, vitamin D synthesis and the development of skin cancers, all of which may involve skin MCs. At the cellular level, exposure of the skin to UVR also results in a large and diverse set of responses of cutaneous cells such as proliferation, differentiation, apoptosis, the release of mediators, and the expression of miRNA profiles . Skin MCs may be affected by these effects of UVR directly and indirectly, and they may be involved as intermediaries of UVR effects on other skin cells.…”

Effects of Narrow Band UVB (311 nm) Irradiation on Epidermal Cells

“…Luo et al [21,23] observed, that single low dose of NB-UVB irradiation (dose below or equal to 100 mJ/cm 2 ) in combination with retinoids (acitretin or tazarotene) inhibits the cell growth in vitro to significantly greater extent than therapy with these drugs alone. As suggested by the authors [21,23] this synergistic effect might be, at least partially, mediated by heparin-binding epidermal-growth-factor like growth factor (HB-EGF), which was up-regulated both upon NB-UVB irradiation and retinoid treatment [21]. Unlike other members of the family of epidermal growth factors, HB-EGF slows proliferation of keratinocyte and, on the other hand, accelerates their migration, a feature that might be important in wound healing [26].…”