Biomedical subjects

Cheng-Che E Lan

Publications and source records attributed to Cheng-Che E Lan.

9 recordsLinked to original sources

PubMed2006

Low-energy helium-neon laser induces locomotion of the immature melanoblasts and promotes melanogenesis of the more differentiated melanoblasts: recapitulation of vitiligo repigmentation in vitro.

Helium-neon laser (He-Ne Laser, 632.8 nm) is a low-energy laser that has therapeutic efficacy on various clinical conditions. Our previous study has demonstrated efficacy of He-Ne laser on vitiligo, a disease characterized by skin depigmentation. To regain skin tone on vitiligo lesions, the process began by the migration of the immature melanoblasts (MBs) to the epidermis, which was followed by their functional development to produce melanin. In this study, we investigated the physiologic effects of He-Ne laser irradiation on two MB cell lines: the immature NCCmelb4 and the more differentiated NCCmelan5. The intricate interactions between MBs with their innate extracelluar matrix, fibronectin, were also addressed. Our results showed that He-Ne laser irradiation enhanced NCCmelb4 mobility via enhanced phosphorylated focal adhesion kinase expression and promoted melanogenesis in NCCmelan5. In addition, He-Ne laser decreased the affinity between NCCmelb4 and fibronectin, whereas the attachment of NCCmelan5 to fibronectin increased. The alpha5beta1 integrin expression on NCCmelb4 cells was enhanced by He-Ne laser. In conclusion, we have demonstrated that He-Ne laser induced different physiologic changes on MBs at different maturation stages and recapitulated the early events during vitiligo repigmentation process brought upon by He-Ne laser in vitro.

Animals↗

PubMed2006

Diagnostic role of soluble fas ligand secretion by peripheral blood mononuclear cells from patients with previous drug-induced blistering disease: a pilot study.

Toxic epidermal necrolysis and Stevens-Johnson syndrome are severe blistering diseases generally considered to be hypersensitivity reaction to drugs. The aim of this study is to explore the diagnostic role of soluble Fas ligand secretion by peripheral blood mononuclear cells (PBMCs) in patients with previous drug-induced blistering diseases with or without stimulation with the offending drug. The results revealed that PBMCs from the patient group showed significant soluble Fas ligand secretion after stimulation with 100 microg/ml culprit drug (p<0.05). No significant change was seen in the control groups (p>0.05). Taken as a group, PBMCs from the patient group secreted more soluble Fas ligand than the normal control group regardless of drug stimulation. These results indicate that individuals whose PBMCs are high secretors of soluble Fas ligand are prone to severe toxic epidermal necrolysis/Stevens-Johnson syndrome. The possibility of using soluble Fas ligand secretion as a tool for retrospective determination of culprit drugs in patients with previous drug-induced blistering disease awaits further investigation.

Adult↗

PubMed2006

Basic fibroblast growth factor promotes melanocyte migration via increased expression of p125(FAK) on melanocytes.

Vitiligo is an acquired pigmentary disorder characterized by depigmentation of skin and hair. Melanocyte migration is an important event in re-pigmentation of vitiligo. We have demonstrated that narrow-band ultraviolet B (UVB) irradiation stimulated cultured keratinocytes to release a significant amount of basic fibroblast growth factor (bFGF). Furthermore, narrow-band UVB enhanced migration of melanocytes via increased expression of phosphorylated focal adhesion kinase (p125(FAK)) on melanocytes. The aim of this study was to investigate the effect of recombinant human bFGF (rhbFGF) on melanocyte migration. The relationship between the expression of p125(FAK) and melanocyte migration induced by rhbFGF was also studied. Our results demonstrated that rhbFGF significantly enhanced migration of melanocytes and p125(FAK) expression on melanocytes. Herbimycin A, a potent p125(FAK) inhibitor, effectively abolished rhbFGF-induced melanocyte migration. The combined results indicated that p125(FAK) plays an important role in the signal transduction pathway of melanocyte migration induced by bFGF.

Benzoquinones↗

PubMed2005

Effects of arsenic and UVB on normal human cultured keratinocytes: impact on apoptosis and implication on photocarcinogenesis.

Inorganic arsenic is an environmental toxin and a human carcinogen. Being a co-mutagen, arsenic enhances carcinogenesis of ultraviolet irradiation on the mouse skin. Apoptosis, a well-regulated cell death process, is essential for cell development and tissue homeostasis. Dysregulation of apoptosis will lead to various kinds of pathological conditions, such as cancers. The purpose of this study is to investigate the apoptotic effect induced by the interactions of arsenic and UVB on cultured human keratinocytes. Cultured keratinocytes were treated with sodium arsenite (1 microM) and/or UVB 50 mJ/cm2 irradiation in different combinations, including arsenic alone (As group), UVB alone (UVB group), arsenic followed by UVB (As/UVB group), and UVB followed by As (UVB/As group) treatments. Our results revealed that a low concentration of sodium arsenite did not induce keratinocytes apoptosis. The UVB group showed obvious elevation of caspase-8, -9, and -3 activities in addition to strong induction of apoptosis as determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine nick-end labeling (TUNEL) assay. Similar pro-apoptotic effects were observed in the UVB/As group. In contrast, only subtle changes of cell morphology and survival rate were noticed in the As/UVB group. In addition, the results of Western blot and activity assay of caspase-8, -9, and -3 revealed that neither the receptor nor the mitochondrial apoptotic signaling pathway was activated in the As/UVB group. Therefore, we conclude that the pretreatment of keratinocytes with sodium arsenite decreased the pro-apoptotic effects induced by UVB. This finding corroborated with the animal model studying the effects of arsenic and UVB on carcinogenesis. The molecular mechanisms by which arsenic decreased UVB-induced apoptosis remain to be elucidated.

Apoptosis↗

PubMed2005

Pigmentation in basal cell carcinoma involves enhanced endothelin-1 expression.

Basal cell carcinoma (BCC) is the most prevalent malignant skin tumor. In Asian patients, marked pigmentation in BCC lesions is often observed. Recently, endothelins (ETs) have been implicated to participate in the pigmentation process of BCC. Therefore, we set out to investigate the involvement of ET in the pigmentation process of BCC and the potential regulators in the pigmentation pathway. We explored the effects of an established BCC cell line on melanocytes. The growth factor profiles of BCC culture supernatant and effects of supernatant on melanocytes were documented. Potential regulators involved in the pigmentation pathway were also studied. The immunohistochemical staining of pigmented and non-pigmented BCC specimens was performed to confirm our in vitro findings. Our results showed that BCC supernatant contained significant amount of ET-1, basic fibroblast growth factor, and nerve growth factor. Furthermore, BCC supernatant stimulated melanin formation of cultured melanocytes. Addition of ET-receptor antagonist abrogated the melanogenic effect of BCC supernatant on melanocytes. Introduction of UVB irradiation decreased the ET-1 secretion by BCC cells. Immunohistochemical staining of the pigmented facial BCC specimens showed prominent expression of ET-1 on pigmented BCC, while the non-pigmented facial BCC specimens showed little ET-1 reactivity. Tumor necrosis factor-alpha (TNF-alpha) staining showed little expression on BCC specimens, regardless of pigmentation status. In summary, our results indicate that enhanced ET-1 expression in pigmented BCC plays an important role in the hyperpigmentation of this tumor. Moreover, this enhanced ET-1 cascade showed little correlation with UV irradiation and TNF-alpha expression in our study.

Basal Cell Carcinoma↗

PubMed2004

Narrow-band ultraviolet-B stimulates proliferation and migration of cultured melanocytes.

Narrow-band ultraviolet-B (UVB) radiation is an effective treatment for vitiligo vulgaris. However, the mechanisms of narrow-band UVB in inducing repigmentation of vitiligo lesions are not thoroughly clarified. The purpose of our study was to investigate the effects of narrow-band UVB irradiation on melanocyte proliferation and migration in vitro. Our results showed that the cell counts as well as [3H]thymidine uptake of melanocytes were significantly enhanced by narrow-band UVB-irradiated keratinocyte supernatants. In these supernatants, a significant increase in basic fibroblast growth factor (bFGF) and in endothelin-1 (ET-1) release was observed. bFGF is a natural mitogen for melanocytes, whereas ET-1 can stimulate DNA synthesis in melanocytes. This stimulatory effect of melanocyte proliferation by supernatants derived from narrow-band UVB-irradiated keratinocytes was significantly reduced by a selective endothelin-B (ET-B) receptor antagonist (BQ788), suggesting an essential role of ET-1 on melanocyte proliferation. Our results of time-lapse microphotography revealed a stimulatory effect of narrow-band UVB irradiation on melanocyte migration. Focal adhesion kinase (FAK) plays a pivotal role in cell migration. Phosphorylated FAK (p125(FAK)) expression on melanocyte was enhanced by narrow-band UVB irradiation. In this study, narrow-band UVB irradiation stimulated a significant increase in matrix metalloproteinase-2 (MMP-2) activity in melanocyte supernatants. Narrow-band UVB-irradiation-induced migration of melanocytes was significantly annihilated by the addition of p125(FAK) inhibitor (herbimycin-A) or MMP-2 inhibitor (GM6001). These results suggest that p125(FAK) and MMP-2 activity play important roles in narrow-band UVB-induced migration of melanocytes. Our results provide a theoretical basis for the effectiveness of narrow-band UVB irradiation in treating vitiligo.

Cell Movement↗

PubMed2003

Effects of gallium on immune stimulation and apoptosis induction in human peripheral blood mononuclear cells.

Gallium is commonly used in the semiconductor industry and medical field. Biologically, gallium is able to interrupt iron metabolism. Exposure to gallium has been shown to affect the human immune system. The purpose of this study was to investigate the in vitro biological effects of different gallium concentrations on cultured human peripheral blood mononuclear cells (PBMCs) in terms of cell growth, cytokine release, and apoptosis induction. In addition, the in vivo effects of gallium were analyzed by Wistar rat model. Our results revealed that low concentrations (1-10 microg/ml) of gallium promoted cells to enter the S phase of cell cycle and enhanced cellular release of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma, both in vitro and in vivo. In contrast, high concentrations of gallium (50-100 microg/ml) induced apoptosis. Furthermore, gallium-induced cytokine release and apoptosis could be inhibited by iron-saturated transferrin (Tf-Fe). These results suggest that the concentration-dependent effects of gallium on PBMCs are related to iron metabolism.

Adjuvants, Immunologic↗

PubMed2003

Tacrolimus ointment for the treatment of atopic dermatitis: report of first clinical experience in Taiwan.

Atopic dermatitis (AD) is a pruritic recurring inflammatory skin disease. Recently, topical tacrolimus has been developed to treat AD. This report presents the first clinical experience with topical tacrolimus in Taiwan. This open-label, single-arm study was conducted at three centers from February to May 2002. The duration of each individual treatment was 4 weeks. Two groups were defined: pediatric and adult. Efficacy was evaluated on the basis of the physician's global evaluation at the end of treatment. Success was defined as at least 50% improvement. Other evaluations included the Eczema Area and Severity Index (EASI), the percentage of body surface area (BSA) involved, the patient's assessment of pruritus, and the patient's assessment of overall response. Safety profile was established by monitoring changes in hematology and biochemistry profiles and tacrolimus concentration in blood. All adverse events were recorded. Twenty-six pediatric patients and 42 adult patients were enrolled. Overall success rates were 80.8% and 82.1% in the pediatric and adult groups, respectively. The declines in EASI, percentage of BSA affected, and patient's assessment of pruritus were significant (p < 0.001); 88% and 100% of pediatric and adult patients, respectively, reported a favorable response to treatment. Changes in blood samples were unremarkable. Of pediatric and adult patients, 61.5% and 76.2%, respectively, reported adverse events. The most common adverse event reported was skin burning, which did not result in discontinuation of therapy. This report reveals that tacrolimus ointment is effective and safe for the treatment of AD in Taiwanese patients.

Adolescent↗

PubMed2003

Relapsing ulcerative papules over bilateral hands and scrotum in an Asian man: an atypical manifestation of primary cutaneous CD30-positive lymphoma.

A 33-year-old Taiwanese man presented at our clinic with multiple erythematous ulcerated papules over his bilateral hands. CD30-positive anaplastic large cell lymphoma (CD30+ ALCL) was diagnosed by an incisional biopsy. After a thorough survey for extracutaneous involvement, the diagnosis of primary cutaneous CD30+ ALCL was established. Due to spontaneous regression of some skin lesions, the patient refused therapeutic intervention. Subsequently, an ulcerative nodule arose over the scrotum. It spontaneously regressed 5 weeks later. Although histologically alarming, this particular lymphoma bears favorable prognosis. Thus, recognition of this entity is of great importance, because it may prevent patients from undergoing unnecessary aggressive treatment. To our knowledge, CD30+ ALCL has not been reported to evolve in the pattern similar as observed in our patient. Thus, this Asian man presents a rare presentation of CD30+ ALCL.

Adult↗