Abstract |
Bowen's disease (BD), a carcinoma in situ of the skin, has been identified as an early lesion in arsenic carcinogenesis. Patients with arsenic-induced Bowen's disease (As-BD) showed both cutaneous and systemic immune dysfunctions. We set out to evaluate the interactions between keratinocytes and lymphocytes in the context of As-BD carcinogenesis. Our results showed that As-BD lesions demonstrated a significant dermal CD4+ cell, an essential regulator of proper tumor immunity, undergoing apoptosis. In addition, it was found that the As-BD patients have lower percentage of peripheral CD4+ cells as compared with control subjects. However, the CD4+ cells from As-BD patients were less susceptible to arsenic-induced apoptosis, due to reduced tumor necrosis factor receptor 1 expression. Interestingly, arsenic was found to induce Fas expression on CD4+ cells and increase the soluble Fas ligand (sFasL) production from keratinocytes. This sFasL-containing keratinocyte supernatant was able to induce comparable CD4+ cell apoptosis for both patients and controls. Using immunofluorescent staining, increased FasL was observed in keratinocytes of As-BD lesions and Fas was expressed among infiltrating CD4+ cells. Our findings suggested that systemically, the percentage of CD4+ cells was decreased in the peripheral blood of As-BD patients. These residual CD4+ cells were less susceptible to arsenic-induced apoptosis. However, once infiltrated into the As-BD lesions, the selective CD4+ cell apoptosis might be mediated by FasL from keratinocytes. This additional tumor-anti-immune phenomenon present in the cutaneous environment provides a reasonable explanation for frequent occurrence of arsenic cancers in the skin.
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Authors | Wei-Ting Liao, Chia-Li Yu, Cheng-Che E Lan, Chih-Hung Lee, Chung-Hsing Chang, Louis W Chang, Huey-Ling You, Hsin-Su Yu |
Journal | Carcinogenesis
(Carcinogenesis)
Vol. 30
Issue 6
Pg. 1064-72
(Jun 2009)
ISSN: 1460-2180 [Electronic] England |
PMID | 19376847
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Fas Ligand Protein
- Arsenic
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Topics |
- Aged
- Apoptosis
(drug effects)
- Arsenic
(toxicity)
- Bowen's Disease
(chemically induced, immunology, pathology)
- CD4-Positive T-Lymphocytes
(drug effects, pathology)
- Cell Transformation, Neoplastic
(drug effects)
- Cells, Cultured
- Fas Ligand Protein
(metabolism)
- Female
- Humans
- Immunity, Active
(drug effects)
- Keratinocytes
(drug effects, immunology, metabolism)
- Male
- Middle Aged
- Skin Neoplasms
(chemically induced, immunology, pathology)
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