Hamm-Ming Sheu

Anticancer activity evaluation of the Solanum glycoalkaloid solamargine - Triggering apoptosis in human hepatoma cells

Solamargine, an herbal and molluscicidal medicine derived from Solanum incanum, is a steroidal alkaloid glycoside. To characterize the anticancer mechanism of solamargine on human hepatoma cells (Hep3B), changes of cell morphology, DNA content, and gene expression of cells after solamargine treatment were studied. The appearance in solamargine-treated cells of chromatin condensation, DNA fragmentation, and a sub-G(1) peak in a DNA histogram suggests that solamargine induces cell death by apoptosis. The maximum number of dead Hep3B cells was detected within 2 hr of incubation with constant concentrations of solamargine, and no further cell death was observed after an extended incubation with solamargine, indicating that the action of solamargine was irreversible. To determine the susceptibility of cell phases to solamargine-mediated apoptosis, Hep3B cells were synchronized at defined cell cycles by cyclosporin A, colchicine, and genistein, followed by solamargine treatment. The IC(50) values of solamargine for control, G(0)/G(1)-, M-, and G(2)/M-synchronized Hep3B cells were 5.0, > 10, 3.7, and 3.1 microg/mL, implying that cells in the G(2)/M phases are relatively susceptible to solamargine-mediated apoptosis. In addition, a parallel up-regulation of tumor necrosis factor receptor (TNFR)-I and -II on Hep3B cells was detected after solamargine treatment, and the solamargine-mediated cytotoxicity could be neutralized with either TNFR-I or -II specific antibody. Therefore, these results reveal that the actions of TNFR-I and -II on Hep3B cells may be independent, and both are involved in the mechanism of solamargine-mediated apoptosis.

Mast cell degranulation and elastolysis in the early stage of striae distensae

The lesions of nine patients with early striae distensae (SD) during puberty were examined by light and electron microscopy. Specific changes were seen in very early stage SD, and in clinically uninvolved skin 0.5 to 3 cm remote from the edge of the long axis of the SD lesions. Sequential changes of elastolysis accompanied by mast cell degranulation appeared first, followed by an influx of activated macrophages that enveloped fragmented elastic fibers. The relationships among elastic fibers, mast cells, and macrophages seen in the present work suggest their critical roles in the process of SD formation, especially in the early stage. Our results also indicate that the elastic fiber is the primary target of the pathological process, and the abnormalities extend as far as 3 cm beyond the lesion into normal skin.

Traffic-Related Air Pollution, Climate, and Prevalence of Eczema in Taiwanese School Children

The prevalence of childhood eczema is increasing in many countries. Epidemiological studies, however, say little of its association to outdoor air pollution and climate factors. We conducted a nationwide survey of middle-school students in Taiwan from 1995 to 1996. The 12-month prevalence of eczema was compared with air monitoring station data of temperature, relative humidity, and criteria air pollutants. A total of 317,926 children attended schools located within 2 km of 55 stations. Prevalence rates of recurrent eczema were 2.4 and 2.3% in boys and girls, respectively, with prevalence rates of flexural eczema 1.7% in both sexes. After adjustment for possible confounders, flexural eczema was found to be associated with traffic-related air pollutants, including nitrogen oxides and carbon monoxide. Recurrent eczema was associated with traffic-related air pollution only in girls. There were no associations for the highest monthly means of temperature, whereas the annual means and the lowest monthly means of temperature were negatively related to flexural eczema, but only in girls. The lowest monthly mean relative humidity was positively related to eczema. The results suggest that air pollution and climatic factors, which showed stronger associations in girls than boys, may affect the prevalence of childhood eczema.

A novel function of emodin - Enhancement of the nucleotide excision repair of UV- and cisplatin-induced DNA damage in human cells

Nucleotide excision repair (NER) is the main pathway by which mammalian cells remove carcinogenic DNA lesions caused by UV light and many other common mutagens. To explore the effect of emodin on NER, its influence on the repair of UV- and cisplatin-induced DNA damage in human fibroblast cells (WI38) was evaluated. Emodin increased unscheduled DNA synthesis (UDS) of UV-treated cells and reduced cisplatin-induced DNA adducts in WI38 in a concentration-dependent manner, indicating that emodin might promote NER capability in cells. The resultant NER complex is a cooperative assembly of XPF, ERCC1, XPA, RPA, and XPG subunits. The gene regulations of the subunits after emodin treatment were determined by reverse transcription-polymerase chain reaction (RT-PCR) using specific primers. Among the subunits, the expression of ERCC1 in WI38 cells was up-regulated significantly after emodin treatment. All other expressions remained essentially unchanged. In addition, calcium influx in WI38 was increased in proportion to the concentration of emodin. Since UV-induced NER is Ca2+ dependent, elevation of calcium influx may be another mechanism by which emodin facilitates DNA repair. In conclusion, emodin can increase the repair of UV- and cisplatin-induced DNA damage in human cells, and elevated ERCC1 gene expression and Ca2+-mediated DNA repair processes may be involved in the repair mechanism of emodin.

Analysis of Taiwanese ichthyosis vulgaris families further demonstrates differences in FLG mutations between European and Asian populations

Background  Mutations in the gene encoding filaggrin (FLG) were identified to underlie ichthyosis vulgaris (IV) and also shown to predispose to atopic eczema. Until now, no FLG mutations have been described in the Taiwanese population.

Narrow‐Band UVB Treatment of Vitiligo in Chinese

Narrow‐band ultraviolet B (NBUVB) phototherapy has recently been reported to be an effective and safe treatment modality for vitiligo. In the present report, we evaluated the efficacy and safety of NBUVB therapy for vitiligo in Chinese patients. Seventy‐two vitiligo patients treated from 2000 to 2003, were included retrospectively (male: female=33:39, mean age: 38.5). Among them, 61 were non‐segmental type and 11 the segmental type. Treatments were given two to three times a week for a maximum period of one year with an initial dose of 0.2 J/cm2 and a 0–20% increment each session (mean accumulation dose: 155.3 J/cm2). Computer image analysis by Supervise classification was used to estimate the area of vitiligo involvement before and after treatment. An excellent response (75–100% area of repigmentation) was obtained in 9 patients (12.5%) and a good response (50–75%) in 24 (33.3%), a moderate response (25–50%) in 20 (27.8%), and a poor response (0–25%) in 19 (26.4%). In summary, 45.8% of our patients had more than 50% repigmentation. Burns were a side effect in 5 patients (7%) and transient erythema with itching or xerosis was noted in 5 patients (7%). These results indicate that NBUVB phototherapy is an effective and safe treatment choice for generalized vitiligo.

Molecular weight dependence of polyethylene glycol penetration across acetone-disrupted permeability barrier

Abstract Previous studies have demonstrated that permeability barrier disruption by acetone treatment significantly enhances skin permeability to both hydrophilic and amphipathic compounds, but not to highly lipophilic compounds. The purpose of the present study was to investigate the dependence of permeability on molecular weight (MW) in acetone-disrupted hairless mouse skin in contrast to normal skin. Penetration of polyethylene glycol (PEG) 300, 600, and 1000 over 12 h was measured using diffusion cells. High-performance liquid chromatographic methods with refractive index detection were used to separate and quantitate the individual oligomeric species in the PEG samples. Percutaneous penetration of PEGs exhibited slightly steeper MW dependency at a transepidermal water loss (TEWL) of 30–41 g/m 2 per h in comparison with TEWLs of 0–10 (control skin), 10–20, and 20–30 g/m 2 per h, with a higher percentage of smaller oligomer PEGs penetrating than larger ones. Increasing the TEWL of the skin increased the penetration of all the PEG oligomers, and the degree of the enhancement relative to penetration through control skin increased with MW and was maximal for oligomers with a MW ranging from 326 to 414 Da. Within the limit of quantitation of the assay, the MW cut-off for PEG penetration across mouse skin with TEWLs of 0–10, 10–20, and 20–30 g/m 2 per h was 414, 590, and 942 Da, respectively, while all the measurable oligomers up to MW 1074 Da were able to penetrate skin with TEWLs in the range 30–41 g/m 2 per h. The results suggest that not only higher amounts but also more varieties of chemicals may penetrate skin with a compromised barrier than normal skin, implying a higher risk of intoxication and hypersensitization by environmental agents through diseased skin with impaired barrier function.

Modulation of Epidermal Terminal Differentiation in Patients after Long-term Topical Corticosteroids

The expression of the various markers for terminal epidermal differentiation in atrophic skin of patients after long‐term topical corticosteroids (TCS) was studied by electron microscopy, immunofluorescence using antibody to profilaggrin/filaggrin (PF/FG), immunoperoxidase staining using antibody to involucrin, and oil red O stain for neutral lipids of the stratum corneum. Thirty‐nine patients were subdivided into two groups: (A) 19 patients suffering from rebound phenomenon after stopping TCS and (B) 20 patients without rebound phenomenon. Biopsy specimens were taken before ending the use of TCS in both groups. In group A, both the morphological markers (including the different epidermal strata, keratohyalin granules, lamellar granules, and cornified cell envelopes) and the molecular markers (including involucrin, PF/FG, and neutral lipids) of terminal epidermal differentiation were significantly suppressed. On the other hand, the differentiational markers in the atrophic skin of patients without rebound phenomena were only slightly altered. These results suggest that potent TCS not only has antiproliferative actions but also inhibits the differentiation of epidermis, resulting in structural defects in the epidermis, especially the stratum corneum.

Downregulation of HER2/neu receptor by solamargine enhances anticancer drug-mediated cytotoxicity in breast cancer cells with high-expressing HER2/neu

Overexpression of HER2/neu is associated with drug resistance and poor outcome in breast cancer. Solamargine (SM), a glycoalkaloid purified from the herb Solanum incanum, exhibits HER2/neu gene modulation of HER2/neu high-expressing human breast cancer cell line ZR-75-1. SM downregulation of HER2/neu gene expression was determined by RT-PCR and Southern hybridization. Additionally, the membrane-bound HER2/neu receptor in highly HER2/neu-expressing breast cancer cells was determined by radioimmunoassay, immunocytochemistry, fluorescent immunocytochemistry, and flow cytometry. SM significantly decreased the number of HER2/neu receptors on the cell membrane. Methotrexate (MTX), 5-florouracil (5-Fu), and cisplatin (CDDP) are commonly used for breast carcinoma treatment in clinics; however, patients with HER2/neu overexpression exhibit resistance to these anticancer drugs. Notably, combination of MTX, 5-Fu, and CDDP with SM individually increased the susceptibility of breast cancer cells to these chemotherapeutic agents. Experimental results indicated that downregulation of HER2/neu by SM might be an effective strategy for enhancing drug susceptibility of breast cancer cells expressing high levels of HER2/neu.

Prevalence and risk factors of occupational hand dermatoses in electronics workers

The electronics industry is becoming an important mainstream in the workforce in some developed countries and in Taiwan. Among patients with occupational hand dermatitis in northern Taiwan, workers from electronics industries were one of the most important groups. We conducted a field investigation to determine the prevalence, patterns and risk factors of occupational hand dermatoses among electronics workers. The survey was conducted in five electronics plants using a self-administered questionnaire on skin symptoms and risk factors. Skin examination and patch testing were followed for those with symptoms compatible with hand dermatitis. A total of 3070 workers completed the questionnaire. Among them, 302 (9.8%) reported to have symptoms (itching and with either redness/scaling) compatible with contact dermatitis on hands. Hand dermatitis was associated with working in the fabrication unit and personal history of atopy and metal allergy, as well as the following job titles: wafer bonding, cutting, printing/photomasking, softening/degluing, impregnation and tin plating. Among those with reported hand dermatitis, 183 completed skin examination and patch testing, 65/183 (35.5%) were diagnosed as having irritant contact dermatitis (ICD) and 7/183 (3.8%) allergic contact dermatitis. The most important allergens were nickel, cobalt and phenylenediamine. In conclusion, Taiwanese electronics workers have a high risk of having hand dermatitis, especially ICD. Preventive efforts should be focused on the workers with risk factors or at certain worksites.