Kanako Tsunoda

Downregulation of microRNA-211 is involved in expression of preferentially expressed antigen of melanoma in melanoma cells

MicroRNAs (miRNAs) are small non-coding RNAs whose aberrations are involved in the initiation and progression of human cancers. To seek unique miRNAs contributing to melanoma tumorigenesis, we investigated the global miRNA expression profile of 7 melanoma cell lines and 3 primary cultures of neonatal human epidermal melanocytes (NHEMs) using the stem-loop real-time PCR method. We found 7 miRNAs that were commonly downregulated and 18 that were upregulated in all of the melanoma cell lines in comparison with the 3 primary cultures of NHEMs. We focused on one commonly downregulated miRNA (miR-211), and analyzed its relationship to the expression of preferentially expressed antigen of melanoma (PRAME) protein, which is a potential target of miR-211. We found that all melanoma cell lines exhibited marked down--regulation of miR-211 and upregulation of PRAME mRNA/protein expression in comparison with NHEMs (P<0.05). A significant inverse correlation between miR-211 and PRAME protein expression was found in melanoma cell lines and primary cultures of NHEMs (correlation coefficient of -0.733, P<0.05). We demonstrated that overexpression of miR-211 induced a reduction of PRAME protein levels, and confirmed the target specificity between miR-211 and PRAME by luciferase reporter assay. These results suggest that downregulation of miR-211 may be partly involved in aberrant expression of the PRAME protein in melanoma cells.

Nucleus Accumbens-Associated 1 Contributes to Cortactin Deacetylation and Augments the Migration of Melanoma Cells

We investigated the prognostic significance and post-transcriptional acetylation-modification of cortactin (CTTN) via the nucleus accumbens-associated 1 (NACC1)-histone deacetylase 6 (HDAC6) deacetylation system in primary melanomas and melanoma cell lines. Overexpression of CTTN protein was observed in 56 (73%) of 77 stage I-IV melanomas, and was significantly correlated with tumor thickness, lymph node metastasis, distant metastasis, and disease outcome. The patients whose tumors exhibited CTTN overexpression had a poorer outcome than patients without this feature (P=0.028, log-rank test). NACC1 and CTTN proteins, but not HDAC6, were overexpressed in four melanoma cell lines in comparison with a primary culture of normal human epidermal melanocytes. Knockdown of both NACC1 and HDAC6 markedly downregulated the migration activity of all melanoma cell lines (P<0.05), and induced a gain of CTTN protein acetylation status. Confocal microscopy showed that hyperacetylation of CTTN modulated by depletion of both NACC1 and HDAC6 induced disappearance of CTTN protein at the leading edge of migrating cells, resulting in stabilization of the focal adhesion structure and development of actin stress fibers. These data suggest that the acetylation status of CTTN modulated by the NACC1-HDAC6 deacetylation system induces acceleration of melanoma cell migration activity via an actin-dependent cellular process, possibly contributing to aggressive behavior (invasion/metastasis) of the melanoma cells.

Immunohistochemistry for histone h3 lysine 9 methyltransferase and demethylase proteins in human melanomas.

Abstract:Methylation and demethylation of histone H3 lysine 9 (H3K9) play a role in the transcriptional regulation of several cancer-related genes and are closely associated with malignant tumor behavior. A novel study has recently demonstrated that SETDB1, a member of the H3K9 methyltransferases, accelerates tumor formation significantly in a zebrafish melanoma model. However, the expression of H3K9 methyltransferases including SETDB1 and demethylases has not been systematically examined in samples of human melanoma. Here, we used immunohistochemistry to examine the expression of the H3K9 methyltransferases, EHMT2 and SETDB1, and a H3K9 demethylase, LSD1, in 67 patients with melanoma. Overexpression of EHMT2, SETDB1, and LSD1 was observed in 14 (21%), 38 (57%), and 53 (79%) of the 67 patients, respectively. A significant relationship was observed between overexpression of EHMT2 or SETDB1 and aggressive tumor behavior such as lymph node metastasis and/or distant metastasis (P < 0.05), whereas no significant relationship was evident for LSD1 immunoreactivity. Univariate log-rank tests demonstrated that patients with melanoma overexpressing EHMT2 had a poorer outcome (P < 0.001), whereas overexpression of SETDB1 or LSD1 had no prognostic impact. These results suggest that overexpression of EHMT2 might be a prognostic marker in patients with melanoma.

Case of malignant melanoma associated with a sarcoid reaction

phototherapy may be ineffective in the treatment of facial lesions. Methotrexate may represent an alternative treatment option or adjunct for ICH, as a number of studies describe beneficial effects of low-dose methotrexate in cases of Langerhans cell histiocytosis. Low-dose methotrexate may have a more favorable side-effect profile than other antineoplastic treatments for ICH. This patient experienced a prompt and significant beneficial effect from lowdose methotrexate. An attempt to taper the patient off methotrexate was unsuccessful due to the rapid development of new lesions. In cases of widespread ICH, especially in individuals with facial involvement, methotrexate may represent a valuable treatment option.

Downregulation of cylindromatosis gene, CYLD, confers a growth advantage on malignant melanoma cells while negatively regulating their migration activity

The cylindromatosis gene (CYLD) encodes a deubiquitinase that was initially identified as a tumor suppressor and has recently been investigated in connection with a variety of normal physiological processes. In contrast to its cell-proliferative activity, the effect of CYLD protein on cell migration has been a matter of debate. We investigated the effect of CYLD-siRNA on the migration activity of malignant melanoma cells. Expression of CYLD mRNA/protein was lower in 6 of 8 malignant melanoma cell lines than in 3 sets of primary-cultured normal human epidermal melanocytes. Knockdown of CYLD significantly increased the proliferation activities of two melanoma cell lines (p<0.05), along with BCL3 nuclear translocation followed by CCND1 overexpression. In contrast to the proliferation-related activity, CYLD knockdown significantly decreased the cell migration of all the melanoma cell lines (n=7, p<0.05), and we demonstrated that the mechanism regulating melanoma cell migration was activation of RAC1 through the action of CYLD. Our findings provide new insight into the role of CYLD-induced RAC1 activation in melanoma cell migration.

Treatment of facial telangiectasia with a small spot of intense pulsed light: a case series of three patients.

Intense pulsed light (IPL) technology has long been used in the treatment of facial telangiectasia. While the large spot size of traditional IPL devices offers rapid coverage, it has limitations in terms of visibility and uniform contact with the skin in contoured areas of the face. The novel IPL used in this study had a small spot size (6.35 mm) and shorter wavelength (500–635 nm), allowing the use of high fluence without burning the normal epidermal tissue surrounding the lesion, thus providing better efficacy. Treatment of facial telangiectasia using small‐spot IPL is effective with a low risk of dermatological damage, and its uses for medical care are expected to diversify.

Successful treatment of erythematotelangiectatic rosacea with intense pulsed light: Report of 13 cases

Here, we describe the use of intense pulsed light (IPL) treatment for 13 cases of erythematotelangiectatic rosacea delivered in three sessions. For two‐step irradiation, after the whole face had been irradiated using conventional IPL equipment covering a wide area, localized IPL spot irradiation was performed for visibly dilated capillaries. The therapeutic effect was evaluated by image analysis using Image J and scored by 10 dermatologists using two IPL instruments in combination. This therapeutic approach was found to be much more effective than irradiation using a single instrument. Our findings demonstrate that IPL irradiation using the present method can deliver a sufficient therapeutic effect even with a small number of treatment sessions. Although rosacea is difficult to treat, we believe that IPL can be therapeutically useful in such cases.

A case of pigmented pilomatricoma (calcifying epithelioma): the role of mast cells in pigmentation

A healthy 10-year-old Japanese girl presented with a symptomless cutaneous tumour on her left upper arm. The tumour, 7 mm in diameter with a hard consistency, had been present for two months and gradually increased in size. Its surface was smooth with a slightly bluish hue (figure 1A). Pilomatricoma was clinically suspected, and surgical excision was performed. Microscopic examination of the specimen revealed a well-defined lesion located in the dermis, showing proliferation of shadow cells and [...]

A Case of Cellular Fibrous Histiocytoma on the Right Elbow with Repeated Relapse within a Short Period

Cellular fibrous histiocytoma, a variant of fibrous histiocytoma, is a designation used for lesions showing increased cellularity with a fascicular growth pattern and frequent extension into the subcutis. Here we describe a case of cellular fibrous histiocytoma showing repeated recurrence in a 36-year-old woman who initially presented with a 2-cm cutaneous tumor on her right elbow. Histopathologically, the first resected specimen demonstrated irregularly arranged collagen fibers mixed with scattered proliferating plump to spindle-shaped fibrohistiocytes. However, examination of the resected specimens obtained after recurrence showed that the cellularity had increased, the spindle-shaped cells showing monomorphic proliferation with a fascicular and storiform growth pattern extending into the subcutis, as well as an increase of Ki-67 positivity. Since the lesion showed repeated relapse within a short period, we performed wide-field resection of the tumor with a 3-cm margin. Currently, 48 months after surgery, there has been no local recurrence or metastasis, but continuous strict follow-up will be necessary.

A case of atypical fibrous histiocytoma with positivity for CD163 and CD44.

Atypical fibrous histiocytoma (AFH) is a variant of der-matofibroma (DF) that was first described by Fukamizu et al. (1) in 1983. Histologically AFH is characterized by proliferation of dermal spindle cells composed mainly of atypical histiocytic cells with striking nuclear pleo-morphism and atypia, in a background of classic fibrous histiocytoma (2). It is known that many cases of AFH follow a benign course if complete excision is carried out (2, 3). However, because the tumour cells are atypical, AFH must be differentiated from tumours of intermediate malignancy, such as dermatofibrosarcoma protuberans (DFSP) or atypical fibrous xanthoma (AFX), as well as more malignant tumours, such as pleomorphic dermal sarcoma (PDS)/malignant fibrous histiocytoma (MFH). We report here a case of AFH on the left upper arm of a 63-year-old woman and describe its immunoreactivity in detail. We also discuss the points of histological and immunohistological differentiation between AFH and other cutaneous spindle cell tumours. A 63-year-old woman presented with an 8-month history of a symptomless, slowly growing swelling on the left upper arm. The patient had no unusual medical or family history. Clinical examination revealed an 8-mm black-purplish hard mass with peripheral erythema (Fig. 1A). The tumour had arisen at a site without any known previous history of injury. A haemangioma was clinically suspected, and surgical excision was performed. Microscopic examination revealed a well-defined lesion, located in the dermis and extending to the subcutaneous tissue, with epidermal hyperplasia and a grenz zone (Fig. 1B). The lesion was composed largely of interlacing fascicles of predominant histiocyte-like eosinophilic spindle cells with elongated or plump vesicular nuclei, arranged in a storiform pattern. Abundant pleomorphic giant cells with huge bizarre nuclei (bi-lobed and multi-lobed) and histiocytes with large vesicular nuclei and prominent eosinophilic nucleoli were observed (Fig. 1C). In the peripheral region of the tumour, fibroblast-like spindle cells arranged in a storiform or fascicular pattern with collagen bundles were observed, resembling the classic features of DF. No necrosis was present. Foci of chronic inflammatory cells, including lympho cytes and plasma cells, were also evident. As a typical feature, we noted individual prominent hyalinized collagen bundles surrounded by tumour cells, predominantly in the periphery of the lesion (Fig. 1D). The mitotic count was 3 per 10 high-power fields (HPF). Immunohistochemical staining revealed diffuse positivity for vimentin, factor XIIIa, CD68, CD163 (Fig. 1E) and CD44 (Fig. 1F). The lesion showed no reactivity for desmin, CD34, AE1/AE3, desmin, S-100 …