Chi Yeon Kim

Induction of Melanogenesis by Rapamycin in Human MNT-1 Melanoma Cells

Background Melanogenesis is one of the characteristic parameters of differentiation in melanocytes and melanoma cells. Specific inhibitors of phosphatidylinositol 3-kinase (PI3K), such as wortmannin and LY294002, stimulate melanin production in mouse and in human melanoma cells, suggesting that PI3K and mammalian target of rapamycin (mTOR) might be involved in the regulation of melanogenesis. Objective The involvement of the mTOR pathway in regulating melanogenesis was examined using human MNT-1 melanoma cells, and the effects of the potent inhibitor of mTOR, rapamycin, in the presence or absence of α-melanocyte-stimulating hormone (α-MSH) were evaluated. Methods In cells treated with rapamycin, cell viability, melanin content, and tyrosinase (TYR) activity were measured and compared with untreated controls. Protein levels of TYR, tyrosinase-related protein (TYRP)-1, TYRP-2, and microphthalmia-associated transcription factor (MITF) were also analyzed by Western blot. Results In rapamycin-treated cells, the melanin content increased concomitantly with an elevation in TYR activity, which plays a major role in melanogenesis. There was also an up-regulation of TYR, TYRP-1, and MITF proteins. Combined treatment with rapamycin or wortmannin and α-MSH increased melanogenesis more strongly than α-MSH alone. Conclusion Rapamycin-induced melanin formation may be mediated through the up-regulation of TYR protein and activity. Furthermore, rapamycin and wortmannin, inhibitors of mTOR and PI3K, respectively, have co-stimulatory effects with α-MSH in enhancing melanogenesis in melanocyte cells.

Stevens-Johnson Syndrome Induced by Vandetanib

Vandetanib is a once-daily oral anticancer drug that selectively inhibits key signaling pathways in cancer by targeting vascular endothelial growth factor receptors, epidermal growth factor receptors tyrosine kinase, and rearranged during transfection-dependent tumor cell proliferation and survival. The most frequently reported adverse events attributed to vandetanib include diarrhea, elevated aminotransferase, asymptomatic corrected QT interval prolongation, and hypertension. Though a number of randomized, doubleblind studies, including cutaneous adverse events attributed to vandetanib, have been reported along with these general symptoms, no case of Stevens-Johnson syndrome (SJS) has been reported. This paper demonstrates a case of SJS induced by vandetanib.

Treatment of oral lichen sclerosus with 1% pimecrolimus cream.

Lichen sclerosus is a chronic inflammatory mucocutaneous disorder predominately affecting prepubertal girls and postmenopausal women. Isolated lichen sclerosus affecting the oral mucosa is exceedingly rare, and only 13 patients with biopsy-proved isolated oral disease have been reported in the literature. We report on a 7-year-old Korean girl with a well-demarcated 1.2x1.2 cm atrophic white plaque with an erythematous border and focal telangiectasia on the left vermillion lip, extending to the labial mucosa. No other cutaneous surfaces, including genitalia, were involved. An incisional biopsy of the plaque on the lip revealed a patchy lichenoid infiltrate of lymphocytes associated with sclerosis of the papillary dermis and a thinned epidermis consistent with a diagnosis of linear orofacial lichen sclerosus. Treatment with a short course of 1% pimecrolimus cream effectively prevented the progression of this lesion.

Cutaneous Malignant Melanoma Associated with Papillary Thyroid Cancer

As the survival from cutaneous malignant melanoma and its clinical concerns have been steadily increasing, the possibility has been raised of an increased risk of second primary cancers in the patients with malignant melanoma. Especially, recent studies have identified an association between cutaneous malignant melanoma and thyroid carcinoma. We here report on a case of cutaneous malignant melanoma that developed in a 61-year-old female patient who had hypothyroidism caused by papillary thyroid carcinoma. We suggest that the individuals who have cutaneous malignant melanoma may be predisposed to other primary cancers and especially thyroid carcinoma. Continuous monitoring of the thyroid function in melanoma patients is required because hypothyroidism can worsen due to malignant melanoma and this is probably associated with thyroid carcinoma.

Fluconazole Induced Fixed Drug Eruption

We report on a rare case of fluconazole induced fixed drug eruption in a 62-year old female patient. She was referred to our department for multiple erythematous itchy maculopatches on the face, neck, both upper arms, and trunk area, which had occurred over the previous 6 months. Her attending physician prescribed fluconazole for treatment of onychomycosis. Patch test and oral provocation were performed. The patch test showed a negative result; however, the result for oral provocation was positive, confirming this as a rare case of fluconazole induced fixed drug eruption. To the best of our knowledge, this is the first reported case in Korean dermatologic literature.

Case of punctate palmoplantar keratoderma type I treated with combination of low-dose oral acitretin and topical salicylic acid and steroid

Palmoplantar keratodermas (PPK) are heterogeneous disorders characterized by abnormal keratinization. Especially, punctate PPK (PPPK), one of the subtypes of hereditary PPK, is a rare punctate keratoderma characterized by tiny “raindrop” keratoses having a tendency to coalesce on the edge of soles, which are exposed to sustained pressure. If typical punctate lesions are confined to the palms and soles and the patient has a family history and late onset, it can be considered as PPPK type I (PPKP1), also called Buschke–Fisher–Brauer disease. The exact etiology of PPPK has not been fully understood. Furthermore, no standardized treatment for PPPK has been established and treatment options are limited. Above all, traditional systemic retinoids have been used in several cases, but dose‐related adverse effects are common. Therefore, combination of low‐dose systemic retinoids and adjuvant topical therapy can be an alternative treatment option for PPPK. Herein, we report a case of PPKP1 treated with combination of low‐dose oral acitretin (10 mg/day) and topical salicylic acid and steroid. Despite low capacity, low‐dose acitretin showed excellent regression of the lesions by combined use of topical ointments. The supplementary topical therapy may be useful in reducing the dose of systemic retinoids and preventing potential toxicity.