All-trans retinoic acid induces cell-cycle arrest in human cutaneous squamous carcinoma cells by inhibiting the mitogen-activated protein kinase-activated protein 1 pathway.

BACKGROUND: All-trans retinoic acid (ATRA) has been tried for the treatment and prevention of a number of epithelial cancers. However, the precise mechanism by which ATRA inhibits the growth of cutaneous squamous cell carcinoma (cSCC) remains elusive. AIMS: To determine the suppressive effects of ATRA on the human cSCC cell line SCL-1, and explore the possible mechanisms involved. METHODS: SCL-1 cells were treated with ATRA, then cell proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while apoptosis and cell cycle progression were analysed by flow cytometry. Protein levels of cell-cycle regulatory proteins and the activation of extracellular signal-regulated kinase (ERK) and Jun kinase (JNK) were detected by western blotting analysis. Transcriptional activity of activator protein (AP)-1 was examined by luciferase reporter assay. RESULTS: ATRA inhibited the proliferation of SCL-1 cells and had modest proapoptotic effects. ATRA also induced G1 cell-cycle arrest, inhibited the expression of cyclin D1/cyclin-dependent kinase (CDK)4 and cyclinE/CDK2, and increased the expression of the cyclin-dependent kinase inhibitors p21 and p27. In addition, ATRA significantly decreased the phosphorylation of ERK1/2 and JNK1/2, and inhibited AP-1 transcriptional activity. CONCLUSIONS: ATRA induces cell-cycle arrest in human cSCC cells by inhibiting the mitogen-activated protein kinase (MAPK)-AP1 pathway, and could be effective in the prevention and chemotherapy of human cSCC.

The epidemiology of adolescent acne in North East China.

BACKGROUND: Adolescent acne impacts self-esteem and quality of life in adolescents and its aetiology is not fully clarified. OBJECTIVE: The aim of this study was to describe the epidemiological features of adolescent acne in North East China and determine the impact of genetic and environmental factors on the pathogenesis of acne. METHODS: Data were collected from 5696 undergraduates (2920 patients and 2776 controls) using questionnaire. The survey data were analysed using spss version 13.0 and heritability of adolescent acne was calculated using Falconer's method. RESULTS: Total prevalence of adolescent acne was 51.30% (52.74% in males, 49.65% in females). The difference between genders was statistically significant (P < 0.05). Adolescents with a family history of acne had earlier age of onset (P < 0.001). The prevalence of acne in first- and second-degree relatives of acne patients was 22.5% and 7.19%, respectively, significantly higher than in controls (P < 0.001). Heritability of adolescent acne was 78.47 +/- 2.05% in first-degree relatives and 75.05 +/- 3.18% in second-degree relatives. Risk factors to the acne suffers include (in descending order of occurrence), acne family history, mental stress, menstrual disorder, frequent insomnia, high fat diet, being male, dysmenorrhoea, anxiety, sleeping < 8 h per day, depression, fried food, study pressure, spicy food, oily skin and mixed type skin. Protective factors include (presented in descending order of occurrence) dry skin, neutral skin, frequent fruit consumption and computer access time < 2 h daily. CONCLUSION: Adolescent acne includes a familial genetic predisposition. Additional environmental factors of psychological stress, skin oiliness and high caloric diets may also contribute to the onset of acne in Chinese adolescents.

Lichen planus pemphigoides associated with Chinese herbs.

We report a 62-year-old Chinese woman with a 2-year history of lichen planus presenting with extensive violaceous maculopapules and plaques 1 week after taking an oral preparation of Chinese herbs. The patient developed vesiculobullous skin lesions 7 weeks later. Histopathological examination showed subepidermal blisters and adjacent bandlike lymphocytic infiltration. Direct immunofluorescence revealed linear deposits of IgG and C3 along the basement membrane zone. Indirect immunofluorescence showed IgG antibody deposition along the epidermal side of salt-split human skin. Circulating anti-bullous pemphigoid 180 antibodies were detected by ELISA. Lichen planus pemphigoides (LPP) was diagnosed. To our knowledge, this is the first report of LPP associated with oral Chinese herbs.

Combination of short CAG and GGN repeats in the androgen receptor gene is associated with acne risk in North East China.

BACKGROUND: Acne vulgaris is one of the most common skin disorders, and androgen is known to play a key role in the development of acne. However, the exact genetic mechanism by which androgen receptor (AR) gene affects acne development is still unclear. OBJECTIVE: Our study aimed to investigate whether CAG and GGN polymorphism of the AR gene are associated with acne risk. PATIENTS AND METHODS: Two hundred thirty-eight patients and 207 controls were included in the study. The repeat lengths of the AR gene were determined by GeneScan analysis. RESULTS: Men with CAG < 23 and women with CAG < 24 had significant risk compared to those men with CAG > or = 23 [odds ratio (OR), 2.07; 95% confidence interval (95% CI), 1.21-3.54] and women with CAG > or = 24 (OR, 2.05; 95% CI, 1.18-3.56). In males, GGN repeats, considered independently of the CAG repeat, have no significant effect on the acne risk; however, when combined with CAG repeats, the acne patients exhibited significantly higher frequency of the haplotypes CAG < 23/GGN < or = 23 (OR, 3.33; 95% CI, 1.10-10.07; P < 0.05) compared with the controls. CONCLUSION: Our results of this study strongly indicated that a shorter CAG repeat length and specific haplotypes of AR attributed to the risk of acne development and thus could serve as a susceptibility marker.

Expression of haptoglobin in human keratinocytes and Langerhans cells.

BACKGROUND: Epidermal Langerhans cells (LCs) play an important role in cutaneous immunological reactions. Freshly obtained or intraepidermal LCs are incapable of activating autologous naive T cells. However, when they are cultured for 2-3 days, LCs are able to activate autologous T cells. It has been proposed that haptoglobin (Hp) is the inhibitor that prevents LC functional transformation in the skin. Abundant Hp has been found in the cytoplasm of epidermal LCs. However, the source of Hp in LCs has not been addressed. OBJECTIVES: To determine the expression of Hp in epidermal cells, and to provide evidence that there is a functional relationship between LCs and keratinocytes (KCs) through Hp. METHODS: Normal human epidermal cells and HaCaT cells were used for detection of Hp mRNA by in situ hybridization and reverse transcription-polymerase chain reaction, and Hp protein by immunohistochemical staining, immunofluorescence counterstaining and Western blotting. RESULTS: Hp mRNA was expressed in normal human KCs and HaCaT cells, but not in normal human epidermal LCs. Hp protein was detected by immunohistochemical staining and immunofluorescence counterstaining in CD1a+ epidermal dendritic cells (LCs), but not in KCs. Hp protein was weakly expressed by HaCaT cells. CONCLUSIONS: Hp mRNA is present in normal human KCs and HaCaT cells, suggesting that they have the potential to synthesize Hp protein. Normal human epidermal LCs are unable to synthesize Hp protein by themselves, although they have abundant Hp protein in their cytoplasm. It is likely that LCs acquire Hp through an exogenous pathway.

Refined localization of dyschromatosis symmetrica hereditaria gene to a 9.4-cM region at 1q21-22 and a literature review of 136 cases reported in China.

BACKGROUND: Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant pigmentary genodermatosis characterized by hyperpigmented and hypopigmented macules on the extremities, which has recently been mapped to an 11.6-cM interval on chromosome 1q11-21. So far, most cases of DSH have been reported in Japan and dermatologists around the world might think this disorder mainly occurs in Japan. In fact, there are 17 DSH families including 136 cases reported in China since 1980, but most of them are described in Chinese. OBJECTIVES: To refine the previously mapped region that facilitates the identification of the DSH gene and to delineate the clinical and genetic features of Chinese DSH cases by a literature review of 136 cases reported in China. METHODS: We performed genotyping and linkage analysis using polymorphic microsatellite markers at 1q11-22 in two Chinese DSH families, and reviewed all of the DSH cases reported in China since 1980. RESULTS: A cumulative maximum two-point lod score of 3.68 was produced with marker D1S506 at a recombination frequency of theta = 0.00 in these two families. Haplotype analysis refined the DSH locus to a 9.4-cM interval flanked by D1S2343 and D1S2635. The genetic and clinical features of Chinese cases with DSH were summarized. In some Chinese cases, hyperpigmented and hypopigmented macules were scattered on the neck and chest, but among Japanese patients there were no similar skin lesions to be reported on these sites. CONCLUSIONS: This study confirms linkage of DSH to a previously mapped region and refines the DSH gene to a 9.4-cM interval at 1q21-22. Likewise, the literature review indicates that DSH is not an uncommon disorder in China and the differences in the distribution of skin lesions could be related to race and environment.

Reactivity of monoclonal antibody OKM5 with sebaceous carcinoma.

Two cases of sebaceous carcinoma (SC), as well as epithelial tumours, melanoma, and lymphoma, were examined using immunoperoxidase and a panel of monoclonal antibodies on cryostat sections. The results showed that, whereas all SC cells in both cases reacted strongly with monoclonal antibody OKM5, other tumour cells (except juvenile xanthogranuloma cells) did not. The pagetoid cells within the epidermis of SC also reacted with OKM5 antibody. Although the nature of the phenomenon merits further study, this reactivity, or cross-reactivity, might possibly aid diagnosis of SC.