NF1 gene silencing induces upregulation of vascular endothelial growth factor expression in both Schwann and non-Schwann cells.

Neurofibromatosis type I (NF1) is associated with typical hypervascular tumors, including neurofibroma, glioma, malignant peripheral nerve sheath tumors (MPNST) and glomus tumors. Previously, we and other groups reported that neurofibromas showed high-level expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor involved in neovascularization. However, the molecular mechanism underlying the upregulation of VEGF in neurofibromas remains unclear. In this study, we examined the effects of Nf1 gene silencing on VEGF expression in Schwann cell and non-Schwann cell line and the upstream mTOR-HIF-1α - VEGF pathway in Schwann cell line. The results indicated that Nf1 gene silencing by lentiviral-mediated RNA interference resulted in elevated expression of VEGF, HIF-1α and phosphorylated mTOR at the protein level. The results obtained from Nf1 gene silencing in murine Schwann cell line analogously suggest that NF1 gene haploinsufficiency in human tumor Schwann cells may directly elicit upregulation of VEGF expression without the tumor microenvironment by activation of the mTOR-HIF-1α - VEGF pathway. We also showed that interleukin-6 is upregulated in Nf1 gene knock-down Schwann cells at the protein level.

Pituitary tumor-transforming gene 1 as a proliferation marker lacking prognostic value in cutaneous squamous cell carcinoma.

Non-melanoma skin cancer is the most frequently occurring type of cancer worldwide and is caused by epidermal carcinogenesis and malignant progression that involve dysregulated expression of proto-oncogenes and tumor suppressor genes. The proto-oncogene pituitary tumor-transforming gene 1 (PTTG1) is a ubiquitously expressed transcription factor that can promote enhanced proliferation of cultured epidermal keratinocytes. To investigate the potential roles of PTTG1 in epidermal carcinogenesis and malignant progression, the expression of PTTG1 was analysed by immunohistochemistry along with Ki67, keratin 10 (K10) and p53 in tissue samples of cutaneous squamous cell carcinomas (SCC), actinic keratoses (AK) and Bowen's disease (BD). Expression levels of PTTG1 were compared among these disease groups to test for correlations with proliferation, differentiation capacity or the existence of mutated tumor suppressor genes in each disease group. In each disease group, the expression levels of PTTG1 correlated positively with those of Ki67, although the differentiation status, measured by K10 expression, did not show any correlation. In contrast, the existence of mutated p53 proteins showed a positive correlation only in the SCC group. Moreover, the expression levels of PTTG1 in SCC did not correlate with known prognostic factors such as TNM staging or tumor thickness. These results suggest that PTTG1 may represent a proliferation marker associated with mutated p53 proteins but is not an informative predictor of poor clinical outcomes in SCC.

A case of sterile transient neonatal pustulosis presenting with large flaccid pustules.

We describe a female neonate with large flaccid pustules on her trunk and extremities. Cultures were negative, and a Wright-stained smear of pustule contents showed numerous eosinophils (>90%). The pustules resolved without leaving pigmentation after 2 weeks. We diagnosed this case as sterile transient neonatal pustulosis.

GATA-3 regulates differentiation-specific loricrin gene expression in keratinocytes.

Loricrin is a major component of the epidermal cornified cell envelope and is expressed only in terminally differentiated keratinocytes. This cell differentiation-specific expression pattern suggests specific regulatory mechanisms for activation of loricrin gene transcription in differentiated keratinocytes. Here, we identified a positive regulatory element in the proximal promoter region of the loricrin gene involved in activation of its expression in differentiated keratinocytes. A database search indicated that this sequence contained a GATA-3 binding motif. Constructs with point mutations in the GATA-3 binding motif showed decreased reporter activity, indicating that GATA-3 positively regulates loricrin gene transcription. Western blotting analysis indicated that GATA-3 is more abundant in differentiated than in undifferentiated keratinocytes. Cotransfection experiments indicated that GATA-3 activates transcription of the loricrin gene in a cooperative manner with c-Fos and Sp1. These findings indicate that GATA-3 contributes to keratinocyte differentiation-specific activation of loricrin gene transcription via interaction with c-Fos and Sp1.

Indocyanine green fluorescence-navigated sentinel node biopsy showed higher sensitivity than the radioisotope or blue dye method, which may help to reduce false-negative cases in skin cancer.

BACKGROUND AND OBJECTIVES: Although sentinel lymph node (SLN) biopsy using radioisotope (RI) and blue dye (BD) achieved a high detection rate, approximately 5% of melanomas with negative SLNs develop nodal metastasis. We tested a new lymphatic navigation method using indocyanine green fluorescence imaging (ICG-FI) to detect such "occult" SLNs. METHODS: Thirty-four skin cancer patients received SLN biopsy with the following three methods: RI (99Tc-tin colloid), BD (2% patent blue), and ICG (0.5% indocyanine green). Lymph nodes detected by any of the three methods were counted as SLNs. RESULTS: ICG-FI detected more SLNs in 8 out of the 34 cases (24%). The average numbers of SLNs detected by ICG-FI, RI, and BD were 2.18, 1.76, and 1.73, respectively. Interestingly, ICG-FI not only detected more SLNs in one basin (ICG-FI: 1.64, RI: 1.50, and BD: 1.51 SLNs per basin), but also detected additional SLNs in other basins (ICG-FI: 1.32, RI: 1.18, and BD: 1.15 basins per case). CONCLUSION: ICG-FI detected SLNs more efficiently than did the conventional methods, and these "occult" SLNs may offer an explanation for some false-negative cases. We recommend using ICG-FI in addition to a conventional method to reduce the risk of overlooking these "occult" SLNs.

Malignant blue nevus arising in a giant congenital cellular blue nevus in an infant.

Giant congenital blue nevus (GCBN) is rare and usually occurs on the scalp. Malignant blue nevus (MBN) is also rare and has a poor prognosis. We report a case of MBN arising in a GCBN on the back. There have been three previous reports of MBN associated with GCBN on the trunk; our case had the earliest onset of MBN arising in a GCBN.

Indolent subcutaneous panniculitis-like T cell lymphoma in a 1-year-old child.

Subcutaneous panniculitis-like T-cell lymphoma is an uncommon form of CD8-positive cytotoxic T-cell lymphoma of the skin that predominantly affects the subcutaneous tissue and is extremely rare in early childhood (<3 yrs). Here, we present an early pediatric case with an indolent form of subcutaneous panniculitis-like T-cell lymphoma occurring at 12 months old. The subcutaneous nodules gradually disappeared spontaneously, and the girl showed excellent prognosis with no aggressive treatment.

Acceleration of UVB-induced photoageing in nrf2 gene-deficient mice.

Ultraviolet (UV) radiation is one of the most important environmental factors involved in the pathogenesis of premature skin ageing, termed photoageing. The harmful effects of UV in photoageing are associated with the generation of reactive oxygen species, and cellular antioxidants act to prevent the occurrence and reduce the severity of UV-induced photoageing. The transcription factor Nrf2 and its cytoplasmic anchor protein, Keap1, are central regulators of the cellular antioxidant response. Here, we investigated the role of the Nrf2-Keap1 pathway in photoageing using nrf2 gene-deficient (nrf2(-/-)) mice. Our results indicated that UVB-irradiated nrf2(-/-) mice showed accelerated photoageing, such as coarse wrinkle formation, loss of skin flexibility, epidermal thickening and deposition of extracellular matrix in the upper dermis. In addition, nrf2(-/-) mice also showed an increase in cutaneous reactivity for the lipid peroxidation product 4-hydroxy-2-nonenal and a significant decrease in cutaneous glutathione level. These findings indicate that Nrf2 plays the important role in the protection against UVB-induced photoageing.

Intraoperative mapping with isosulfan blue of lymphatic leakage during inguinal lymph node dissection (ILND) for skin cancer for the prevention of postoperative lymphocele.

BACKGROUND: Inguinal lymphocele is a well-known complication of inguinal lymph node dissection. Isosulfan blue has been used to identify and treat lymphoceles arising from lymphatics injured during surgery of the groin. However, the preventive use at the time of lymph node dissection has not been reported. OBJECTIVES: We evaluated the potential role of intraoperative injection of isosulfan blue during inguinal lymph node dissection for the prevention of postoperative lymphocele. METHODS: We performed 43 conventional inguinal lymph node dissections (group A) and 7 inguinal lymph node dissections using isosulfan blue injection around the dissected inguinal region (group B) to identify lymphatic leakage intraoperatively. RESULTS: Lymphoceles were observed in 13 of 43 dissections (30.23%) in group A and in 0 of 7 dissections (0%) in group B. The number of detected injured lymphatics ranged from 0 to 6 (mean 3.3) in group B. The mean postoperative lymphatic drainage output was less in group B than in group A. The mean number of days of suction catheter insertion was 4.43 days in group B, and 7.98 days in group A. CONCLUSIONS: The technique during inguinal lymph node dissection presented herein is useful for the prevention of postoperative lymphocele.

A custom-made, low-cost intraoperative fluorescence navigation system with indocyanine green for sentinel lymph node biopsy in skin cancer.

BACKGROUND: Recently, indocyanine green (ICG) fluorescence imaging has been reported as new method to detect sentinel lymph nodes (SLNs). However, high introduction costs limit its use. OBJECTIVE: The purpose of this study was to test an ICG fluorescence detection system constructed with parts commonly available on the market and to compare the SLN detection rate with that of the conventional combined dye and RI methods. METHODS: We constructed this system using a charge-coupled device camera and light-emitting diodes. RESULTS: We could construct our system at a cost of less than USD 1,600. This system could trace lymphatic channels through the skin and detect SLNs in 16 patients with skin cancer. However, SLNs in the neck were difficult to detect through the skin. CONCLUSION: Our system could be assembled at a reasonable cost and allowed us to detect SLNs efficiently. It may be used as an alternative to radiotracer for detecting SLNs located in the groin and axillary regions.

Linear childhood discoid lupus erythematosus following the lines of Blaschko: successfully treated with topical tacrolimus.

The linear arrangement of discoid lupus erythematosus is uncommon. Here, we report a 6-year-old Japanese girl with linear discoid lupus erythematosus following the lines of Blaschko on her face and neck. Topical tacrolimus treatment improved the eruptions. The present case also indicated the important role of epidermal and dermal cells as well as immune cells in the pathogenesis of cutaneous lupus erythematodes.

Enforced ROR(gamma)t expression in haematopoietic stem cells increases regulatory T cell number, which reduces immunoreactivity and attenuates hypersensitivity in vivo.

BACKGROUND: The retinoic acid receptor-related orphan receptor gammat (ROR(gamma)t) is a key transcription factor involved in the generation of T-helper 17 (Th17) cells, which mediate tissue inflammation and autoimmunity. However, recent studies indicated that less than half of all ROR(gamma)t(+) Talphabeta cells express IL-17, while the others are Foxp3(+) Talphabeta cells expressing IL-10. These observations raise questions regarding the role of ROR(gamma)t in the early differentiation process of T cells from haematopoietic stem cells. METHODS: To examine the role of RORyt in T cell differentiation, mice were reconstituted with ROR(gamma)t cDNA-transduced haematopoietic stem cells and the role of ROR(gamma)t in T cell differentiation was studied in a mouse bone marrow transplantation model in vivo. RESULTS: While the number of Th17 cells increased with the reduction in Thl cell number in transplanted mice, peripheral blood Foxp3(+) Talphabeta cell number also increased, which attenuated the severity of contact hypersensitivity on skin exposed to 2,4-dinitrofluorobenzene. The number of non-transduced Foxp3(+) regulatory T cells (Treg cells) also increased in these mice. CONCLUSION: These observations suggest that the enforced expression of ROR(gamma)t in haematopoietic stem cells induces differentiation of Thl7 cells and results in an increase in Foxp3(+) Treg cell number to limit self-tissue damage.

Clinical background of patients with psoriasiform skin lesions due to tumor necrosis factor antagonist administration at a single center.

Paradoxical reaction (PR) occurs when a drug elicits a reaction contrary to what was expected. To clarify the clinical features and genetic background of individuals susceptible to PR, we analyzed the clinical course of patients in whom psoriatic eruptions worsened or newly developed during tumor necrosis factor (TNF) antagonist administration and the role of focal infections and genetic variations. Of 125 patients who received TNF antagonist therapy for psoriasis, acrodermatitis continua of Hallopeau (ACH), generalized pustular psoriasis (GPP), or palmoplantar pustular psoriasis (PPP), eight patients with PR were surveyed at our hospital Dermatology Department between 2010 and 2021. A survey was also done on six patients who received TNF antagonist therapy for Crohn's disease, rheumatoid arthritis, ankylosing spondylitis, and hidradenitis suppurativa and were referred to our department due to PR. Additionally, Sanger sequencing analysis was performed for all exons and flanking introns of IL36RN (interleukin 36 receptor antagonist), CARD14 (caspase recruitment domain-containing protein 14), and AP1S3 (adaptor-related protein complex 1 subunit sigma 3). The clinical assessment of the 14 patients demonstrated an average age at PR onset of 48.4 years, a male : female ratio of 5:9, and a mean administration period until onset of 9.2 months. The clinical types of PR were plaque psoriasis, PPP, GPP, pustulosis, acne, ACH, hair loss, and exacerbation of arthralgia. Histopathology revealed psoriasiform dermatitis in three patients. One patient continued TNF antagonist therapy. All of the patients with psoriasis and GPP had dental infections, suggesting that focal infection may be a risk factor of the development of PR following TNF antagonist therapy. Gene analysis demonstrated CARD14 gene variants associated with RA, CD, AS, or PPP in four patients. In addition, all of the patients with ACH and PPP experienced PR, suggesting that these diseases may predispose patients to PR to TNF antagonist therapy.

Extension of a malignant tailgut cyst to a subcutaneous space in the buttock.

Tailgut cysts are rare benign cystic lesions of the retrorectal space. The recommended treatment is complete resection because these cysts have occasionally shown malignant transformation. However, a high index of clinical suspicion is required to reach a diagnosis. We report a 68-year-old man complaining of a subcutaneous mass in his right buttock. Magnetic resonance imaging (MRI) showed a large cystic mass extending 25.7 cm from the pelvis to the buttock. Radiological features indicated a benign cystic tumor, but the level of serum carcinoembryonic antigen (CEA) (87.5 ng/mL) was increased. An incisional biopsy did not define the true histological nature of the lesion and was not useful for surgical planning. Although MRI could not detect malignant changes, the elevated serum CEA indicated malignant degeneration. The patient required a Miles operation for complete resection. Surgical pathology revealed focal areas of high-grade adenomatous and adenocarcinomatous changes in the cyst wall. After surgery, the serum CEA level decreased to below the normal range. The case presented here shows that early malignant degeneration of TGC is difficult to detect by MRI. Thus, a tailgut cyst should be completely removed, even if radiological examination cannot detect malignant features. Measurement of serum CEA may be helpful when the tumor expresses this antigen.

Chronically recurrent and disseminated tinea faciei/corporis--autoinoculation from asymptomatic tinea capitis carriage.

We report clinical findings in a 12-year-old girl with long-term recurrent and disseminated multiple eruptions of tinea faciei and tinea corporis, which persisted for 10 years. Mycological examination revealed the dermatophyte Trichophyton tonsurans in both scale samples from the body lesions and in brushing samples from her asymptomatic scalp, suggesting that she was an asymptomatic dermatophyte carrier on the scalp, and autoinoculation of the dermatophyte was responsible for the recurrent and disseminated tinea faciei/corporis.

Insulin-derived amyloidosis without a palpable mass at the insulin injection site: A report of two cases.

To date, almost all case reports of insulin-derived amyloidosis described the presence of a subcutaneous mass that was observable on physical examination. This report presents two cases of insulin-derived amyloidosis without palpable masses at insulin injection sites. In both cases, blood glucose concentrations improved, and the insulin dose could be reduced by an average of 45% after changing the insulin injection sites. The insulin absorption at the site was reduced to at most 40% of that at a normal site in one case. Magnetic resonance imaging and ultrasonography were useful to screen and differentiate insulin-derived amyloidosis without a palpable mass. This report showed that insulin-derived amyloidosis without a palpable mass can be present at the insulin injection site, and has similar clinical effects to insulin-derived amyloidosis with palpable masses.

Essential role of Nrf2 in keratinocyte protection from UVA by quercetin.

Much of the cell injury caused by ultraviolet A (UVA) irradiation is associated with oxidative stress. Quercetin is a major natural polyphenol that is known to protect cells from UVA-induced damage. Here, we investigated the molecular mechanism of this protection. Quercetin pretreatment strongly suppressed UVA-induced apoptosis in human keratinocyte HaCaT cells, markedly increased protein levels of the transcription factor Nrf2, induced the expression of antioxidative genes, and dramatically reduced the production of reactive oxygen species following UVA irradiation. Importantly, these beneficial effects were greatly attenuated by downregulating Nrf2 expression. Thus, quercetin protects cells from UVA damage mainly by elevating intracellular antioxidative activity via the enhanced accumulation of a transcription factor for antioxidant genes, Nrf2.

The induction of tumor-specific CD4+ T cells via major histocompatibility complex class II is required to gain optimal anti-tumor immunity against B16 melanoma cell line in tumor immunotherapy using dendritic cells.

We have demonstrated that dendritic cells (DCs) genetically modified to express tumor-associated antigens (TAAs) with retroviral vectors elicit more potential anti-tumor effect than those loaded with peptides because they can prime antigen-specific CD4+ T cells resulting in production of tumor-specific antibody. In this study, we showed the importance of antigen presentation via a major histocompatibility complex (MHC) class II molecule in cancer immunity against non-membrane bound TAAs such as the melanoma antigen gp100 by using DCs derived from MHC class II-deficient mice (C2KO). DCs were prepared by transduction of gp100 cDNA into haematopoietic progenitor cells obtained from C2KO followed by differentiation with cytokines (C2KO-gp/DCs). When C2KO-gp/DCs were inoculated into immunocompetent mice, the mice scarcely primed the antigen-specific Th1 cells and developed fewer CD8 T cells than did those inoculated with transduced DCs prepared from normal mice. The attenuated anti-tumor effect was also confirmed in a postimmunization setting where, while two of eight control mice eradicated the pre-existing melanoma cell line B16 (25%), no mice inoculated with C2KO-gp/DCs did. These results suggested not only the limitation of current protocols using MHC class I-restricted tumor peptides but also the usefulness of DCs expressing gp100 in vaccine therapy against melanoma.

Superimposed segmental dermatitis with chronic prurigo.

Common acquired skin diseases with a polygenic background, such as lichen planus, may show linear or segmental manifestations of underlying systemic skin disease. The linear arrangement in such cases is usually consistent with the lines of Blaschko. Happle summarized the various types of segmental arrangement of common polygenic diseases and proposed a novel designation of superimposed segmental dermatosis. Here, we report a unilateral linear dermatitis distributed along the lines of Blaschko on the leg, which was not self-healing and persisted for at least 6 years without complete remission, and was accompanied by preceding chronic prurigo on the extremities. Histological examination showed subacute spongiotic dermatitis and epidermal infiltration of CD4-positive cells. This case report presents a superimposed segmental dermatitis that arose based on systemic eczematous conditions, such as chronic prurigo.