A Sulfur Containing Melanogenesis Substrate, N-Pr-4-S-CAP as a Potential Source for Selective Chemoimmunotherapy of Malignant Melanoma

N-propionyl-4-S-cysteaminylphenol (N-Pr-4-S-CAP) is a substrate for tyrosinase, which is a melanin biosynthesis enzyme and has been shown to be selectively incorporated into melanoma cells. It was found to cause selective cytotoxicity against melanocytes and melanoma cells after selective incorporation, resulting in the induction of anti-melanoma immunity. However, the underlying mechanisms for the induction of anti-melanoma immunity remain unclear. This study aimed to elucidate the cellular mechanism for the induction of anti-melanoma immunity and clarify whether N-Pr-4-S-CAP administration could be a new immunotherapeutic approach against melanoma, including local recurrence and distant metastasis. A T cell depletion assay was used for the identification of the effector cells responsible for N-Pr-4-S-CAP-mediated anti-melanoma immunity. A cross-presentation assay was carried out by using N-Pr-4-S-CAP-treated B16-OVA melanoma-loaded bone marrow-derived dendritic cells (BMDCs) and OVA-specific T cells. Administration of N-Pr-4-S-CAP induced CD8+ T cell-dependent anti-melanoma immunity and inhibited the growth of challenged B16F1 melanoma cells, indicating that the administration of N-Pr-4-S-CAP can be a prophylactic therapy against recurrence and metastasis of melanoma. Moreover, intratumoral injection of N-Pr-4-S-CAP in combination with BMDCs augmented the tumor growth inhibition when compared with administration of N-Pr-4-S-CAP alone. BMDCs cross-presented a melanoma-specific antigen to CD8+ T cells through N-Pr-4-S-CAP-mediated melanoma cell death. Combination therapy using N-Pr-4-S-CAP and BMDCs elicited a superior anti-melanoma effect. These results suggest that the administration of N-Pr-4-S-CAP could be a new strategy for the prevention of local recurrence and distant metastasis of melanoma.

Elucidation of Melanogenesis Cascade for Identifying Pathophysiology and Therapeutic Approach of Pigmentary Disorders and Melanoma

Melanogenesis is the biological and biochemical process of melanin and melanosome biosynthesis. Melanin is formed by enzymic reactions of tyrosinase family proteins that convert tyrosine to form brown-black eumelanin and yellow-red pheomelanin within melanosomal compartments in melanocytes, following the cascades of events interacting with a series of autocrine and paracrine signals. Fully melanized melanosomes are delivered to keratinocytes of the skin and hair. The symbiotic relation of a melanocyte and an associated pool of keratinocytes is called epidermal melanin unit (EMU). Microphthalmia-associated transcription factor (MITF) plays a vital role in melanocyte development and differentiation. MITF regulates expression of numerous pigmentation genes for promoting melanocyte differentiation, as well as fundamental genes for maintaining cell homeostasis. Diseases involving alterations of EMU show various forms of pigmentation phenotypes. This review introduces four major topics of melanogenesis cascade that include (1) melanocyte development and differentiation, (2) melanogenesis and intracellular trafficking for melanosome biosynthesis, (3) melanin pigmentation and pigment-type switching, and (4) development of a novel therapeutic approach for malignant melanoma by elucidation of melanogenesis cascade.

Antitumor immunity by magnetic nanoparticle-mediated hyperthermia

Magnetic nanoparticle-mediated hyperthermia (MNHT) generates heat to a local tumor tissue of above 43°C without damaging surrounding normal tissues. By applying MNHT, a significant amount of heat-shock proteins is expressed within and around the tumor tissues, inducing tumor-specific immune responses. In vivo experiments have indicated that MNHT can induce the regression of not only a local tumor tissue exposed to heat, but also distant metastatic tumors unexposed to heat. In this article, we introduce recent progress in the application of MNHT for antitumor treatments and summarize the mechanisms and processes of its biological effects during antitumor induction by MNHT. Several clinical trials have been conducted indicating that the MNHT system may add a promising and novel approach to antitumor therapy.

A Case of Systemic Osteomyelitides Due toMycobacterium avium

A case of multiple osteomyelitides due to Mycobacterium avium (M. avium) infection with osteosclerotic bone lesions is reported. A 67-year-old male had been suffering from persistent fever and back pain since October 1999, and 20.0-2.5 mg prednisolone per day was prescribed for continuous inflammatory symptoms in January 2000. Six months later, computed tomography revealed osteosclerotic lesions in the left femur and thoracic vertebrae, but no skin lesion associated with mastocytosis or internal malignancy was identified. In September of 2002, a dome-shaped, soft subcutaneous tumor developed on the upper sternum. Histopathological findings revealed subcutaneous adipose tissue with several foci of tiny abscesses. Two weeks later, creamy pus was discharged through a draining sinus at the center of the wound. M. avium was demonstrated in the pus by Zeel-Nielsen staining and microplate hybridization.

TLR4 and NLRP3 inflammasome activation in monocytes by N-propionyl cysteaminylphenol-maleimide-dextran (NPCMD)

BACKGROUND

N-propionyl cysteaminylphenol-maleimide-dextran (NPCMD) is a toxic tyrosinase substrate developed to treat melanoma.

OBJECTIVE

We investigated the effect of NPCMD on innate immune responses in monocytes.

METHODS

CD14⁺ monocytes and a monocytic cell line, THP-1, were stimulated with NPCMD in vitro. Cytokines in the culture supernatants were determined by ELISA and flow cytometry.

RESULTS

NPCMD stimulated CD14⁺ monocytes and THP-1 cells to secrete TNFα, IL-6 and IL-8, but not IL-10 or IL-12. TNFα secretion from THP-1 cells stimulated with NPCMD was inhibited by addition of an anti-TLR4 mAb in culture. Moreover, NPCMD stimulated production of pro-IL-1β in CD14⁺ monocytes and monocytic cell line THP-1 cells and activated the NLRP3-inflammasome, resulting in production of mature IL-1β. Use of ASC and NLRP3-deficient THP-1 cell lines established involvement of the NLRP3 inflammasome in an IL-1β secretion in treatment with NPCMD. Inhibition of IL-1β secretion by an endocytosis inhibitor, cytochalasin B, and a lysosomal enzyme cathepsin B inhibitor, CA-074 Me, suggested the involvement of lysosomal rupture and leakage of cathepsin B into the cytosol in NLRP3 activation by NPCMD.

CONCLUSION

The immunopotentiating effect of NPCMD mediated by TLR4 and NLRP3 inflammasome activation could be useful for eliciting effective adaptive immune responses against melanoma and other tumors.

T-cell receptor repertoires of tumor-infiltrating lymphocytes after hyperthermia using functionalized magnetite nanoparticles

AIM

Accumulating evidence has indicated that hyperthermia using magnetite nanoparticles induces antitumor immunity. This study investigated the diversity of T-cell receptors (TCRs) in tumor-infiltrating lymphocytes after hyperthermia using magnetite nanoparticles.

MATERIALS & METHODS

Functionalized magnetite nanoparticles, N-propionyl-4-S-cysteaminylphenol (NPrCAP)/magnetite, were synthesized by conjugating the melanogenesis substrate NPrCAP with magnetite nanoparticles. NPrCAP/magnetite nanoparticles were injected into B16 melanomas in C57BL/6 mice, which were subjected to an alternating magnetic field for hyperthermia treatment.

RESULTS

Enlargement of the tumor-draining lymph nodes was observed after hyperthermia. The TCR repertoire was restricted in tumor-infiltrating lymphocytes, and expansion of Vβ11(+) T cells was preferentially found. DNA sequences of the third complementaritydetermining regions revealed the presence of clonally expanded T cells.

CONCLUSION

These results indicate that the T-cell response in B16 melanomas after hyperthermia is dominated by T cells directed toward a limited number of epitopes and that epitope-specific T cells frequently use a restricted TCR repertoire.

Increased caspase-2 activity is associated with induction of apoptosis in IFN-beta sensitive melanoma cell lines

Interferon (IFN) is believed to be one of the most effective anti-melanoma agents. Specifically, IFN-beta has the ability to induce apoptosis of melanoma cells. Induction of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has also been suggested to have a critical role in IFN-beta-induced apoptosis. To characterize the signaling pathway involved in IFN-beta-induced apoptosis, we analyzed the biological effects of IFN-beta on the cell death and caspase activation of melanoma cells. IFN-sensitive cell lines, MM418, SK-mel-23, and SK-mel-118, showed increased apoptotic populations correlated with the activation of caspase-2 and caspase-3 by IFN-beta. IFN-beta-induced apoptosis was significantly suppressed by inhibitors for caspase-2 or caspase-3, but not by inhibitors for caspase-8 or caspase-9 in these cell lines. TRAIL expression was observed in IFN-beta-treated cells of SK-mel-23 and SK-mel-118, but not in those cells of MM418, which showed massive IFN-beta-induced apoptosis and resistance to exogenous TRAIL-mediated apoptosis. G361 was resistant to IFN-beta-induced apoptosis but sensitive to exogenous TRAIL-mediated apoptosis. Furthermore, IFN-beta pretreatment significantly increased the sensitivity against exogenous TRAIL-mediated apoptosis and activation of caspase-2 in G361. These results suggested that caspase-2 activation is commonly associated with induction of IFN-beta-induced apoptosis in IFN-beta-sensitive melanoma cells.

Rab7 is a critical mediator in vesicular transport of tyrosinase-related protein 1 in melanocytes

How melanosomal proteins such as enzymic proteins (tyrosinase and tyrosinase-related proteins, Tyrps) and structural protein (gp100) are transported from Golgi to melanosomal compartments is not yet fully understood. A number of small GTPases have been found to be associated with melanosomes and we have identified one of them, Rab7, a regulator of vesicular transport, organelle motility, phospholipid signaling and cytosolic degradative machinery, as being involved in the transport of Tyrp1 from Golgi to stage I melanosomes. This study further characterizes the role of Rab7 as a regulator of differential sorting of melanosomal proteins in this process. Murine melanocytes were transiently transfected with a plasmid encoding either wild-type (Rab7WT), constitutively active (Rab7Q67L) or dominant-negative (Rab7N125I and Rab7T22N) Rab7. Through immunocytostaining and confocal laser scanning microscopy, we quantitatively compared the bio-distribution of melanosomal proteins between Rab7WT-expressing cells and mutant Rab7-expressing cells. We also characterized their differential elimination from melanosomal compartments by Rab7 by utilizing a proteasome inhibitor, MG132. Our findings indicate that Rab7 plays an important role in differential sorting of tyrosinase, Tyrp1 and gp100 in early melanogenesis cascade, and that it is more specifically involved with Tyrp1 than tyrosinase and gp100 in the trafficking from Golgi to melanosomes and the specific exit from the degradative process.

Agouti protein, mahogunin, and attractin in pheomelanogenesis and melanoblast-like alteration of melanocytes: a cAMP-independent pathway

Melanocortin-1 receptor (MC1R) and its ligands, α-melanocyte stimulating hormone (αMSH) and agouti signaling protein (ASIP), regulate switching between eumelanin and pheomelanin synthesis in melanocytes. Here we investigated biological effects and signaling pathways of ASIP. Melan-a non agouti (a/a) mouse melanocytes produce mainly eumelanin, but ASIP combined with phenylthiourea and extra cysteine could induce over 200-fold increases in the pheomelanin to eumelanin ratio, and a tan-yellow color in pelletted cells. Moreover, ASIP-treated cells showed reduced proliferation and a melanoblast-like appearance, seen also in melanocyte lines from yellow (A^y/a and Mc1r^e/ Mc1r^e) mice. However ASIP-YY, a C-terminal fragment of ASIP, induced neither biological nor pigmentary changes. As, like ASIP, ASIP-YY inhibited the cAMP rise induced by αMSH analog NDP-MSH, and reduced cAMP level without added MSH, the morphological changes and depigmentation seemed independent of cAMP signaling. Melanocytes genetically null for ASIP mediators attractin or mahogunin (Atrn^mg-3J/mg-3J or Mgrn1^md-nc/md-nc) also responded to both ASIP and ASIP-YY in cAMP level, while only ASIP altered their proliferation and (in part) shape. Thus, ASIP–MC1R signaling includes a cAMP-independent pathway through attractin and mahogunin, while the known cAMP-dependent component requires neither attractin nor mahogunin.

N-propionyl-cysteaminylphenol-magnetite conjugate (NPrCAP/M) is a nanoparticle for the targeted growth suppression of melanoma cells

A magnetite nanoparticle, NPrCAP/M, was produced for intracellular hyperthermia treatment of melanoma by conjugating N-propionyl-cysteaminylphenol (NPrCAP) with magnetite and used for the study of selective targeting and degradation of melanoma cells. NPrCAP/M, like NPrCAP, was integrated as a substrate in the oxidative reaction by mushroom tyrosinase. Melanoma, but not non-melanoma, cells incorporated larger amounts of iron than magnetite from NPrCAP/M. When mice bearing a B16F1 melanoma and a lymphoma on opposite flanks were given NPrCAP/M, iron was observed only in B16F1 melanoma cells and iron particles (NPrCAP/M) were identified within late-stage melanosomes by electron microscopy. When cells were treated with NPrCAP/M or magnetite and heated to 43 degrees C by an external alternating magnetic field (AMF), melanoma cells were degraded 1.7- to 5.4-fold more significantly by NPrCAP/M than by magnetite. Growth of transplanted B16 melanoma was suppressed effectively by NPrCAP/M-mediated hyperthermia, suggesting a clinical application of NPrCAP/M to lesional therapy for melanoma. Finally, melanoma cells treated with NPrCAP/M plus AMF showed little sub-G1 fraction and no caspase 3 activation, suggesting that the NPrCAP/M-mediated hyperthermia induced non-apoptotic cell death. These results suggest that NPrCAP/M may be useful in targeted therapy for melanoma by inducing non-apoptotic cell death after appropriate heating by the AMF.

Regulatory factors of pheo- and eumelanogenesis in melanogenic compartments

Melanogenesis, i.e., synthesis of melanin and melanosomes, is a "cascade" of event which is channelled by internal and external regulatory factors. The recognition and selection of this information and subsequent differentiation of melanogenesis (melanin type and melanosomal development) would be regulated significantly by melanosomal membrane. The melanogenesis type could be switched relatively easily by UV light, hormone, and availability of tyrosinase substrate. The role of sulphydryl compounds as a regulatory factor in melanogenesis type (in particular for pheomelanogenesis) may not be tied to its absolute presence or absence, but rather, to the effective concentration within the melanocyte at a given time. It is, therefore, probable that the morphogenesis of melanosomes may not follow immediately in response to melanogenesis-type changes, hence the melanocyte revealing more often mosaic forms of melanosomes in nature after exposure to non-genetic factors. The switch of melanogenesis would be significantly controlled by structural and functional availability of vesiculoglobular bodies which are encoded or associated with HMSA-5 (69 kDa) glycoprotein. This HMSA-5 protein shares a significant homology with gp75 "b-locus" protein. However, because of our hypothesis that vesiculoglobular bodies carry post- (and pre-) tyrosinase regulatory factors involving in both pheo- and eumelanogenesis, the term "b-protein" which focuses only on eumelanogenesis may not be applied to HMSA-5.

Rab7 regulates maturation of melanosomal matrix protein gp100/Pmel17/Silv

Melanosome biogenesis consists of multistep processes that involve synthesis of melanosomal protein, which is followed by vesicle transport/fusion and post-translational modifications such as glycosylation, proteolysis, and oligomerization. Because of its complexity, the details of the molecular mechanism of melanosome biogenesis are not yet fully understood. Here, we report that, in MMAc melanoma cells, wild-type (WT) Rab7 and its dominant-active mutant (Rab7-Q67L), but not its dominant-negative mutant (Rab7-T22N), were colocalized in the perinuclear region with granules containing Stage I melanosomes, where the full-length, immature gp100/Pmel17/Silv was present. It was also found that overexpression of Rab7-Q67L and, to a lesser extent, Rab7-WT increased the amount of proteolytically processed, mature gp100. However, Rab7-T22N did not show such an effect. Moreover, siRNA-mediated Rab7 knockdown considerably inhibited gp100 maturation. These results collectively suggest that the GTP-bound form of Rab7 promotes melanogenesis through the regulation of gp100 maturation in melanoma cells.

Inhibition of endogenous MHC class II-restricted antigen presentation by tacrolimus (FK506) via FKBP51

The effect of tacrolimus (FK506) on down-regulation of IL-2 production by T cells is considered to be mainly responsible for its strong suppression of immunological events. In this study, we show that FK506 also has an affect on antigen presentation by antigen-presenting cells in vitro. FK506 was able to inhibit the presentation of endogenous MHC class II-restricted minor histocompatibility antigens in primary dendritic cells (DC) in vitro, but cyclosporine A (CsA) and rapamycin (RAP) were not. RNA interference (RNAi)-mediated reduction of endogenous FK506-binding protein (FKBP)51 expression resulted in a marked decrease in antigen presentation, suggesting that FKBP51 plays a role in endogenous MHC class II-restricted antigen presentation. Since our model used naturally expressed cytosolic antigens in primary DC, these effects might have been due to novel properties of the immunosuppressive drugs and may allow us to elucidate a new paradigm for the immunosuppressive mechanism of FK506.

Papulonecrotic tuberculid-like eruptions after Bacille Calmette-Guerin vaccination

One of the specific skin lesions occurring after Bacille Calmette-Guerin (BCG) vaccination is generalized tuberculid-like eruptions, which occur rarely, but have a tendency to heal spontaneously. Their pathogenesis and relationship to "true" tuberculids are poorly understood. This report presents a case of a 6-month-old girl who developed generalized papulonecrotic tuberculid-like eruptions after BCG vaccination. The skin lesions healed spontaneously in 3 months. Culture of blood, gastric juice and reverse transcription polymerase chain reaction (RT-PCR) of papulonecrotic skin biopsies were all negative for Mycobacterium tuberculosis. Histopathology of papulonecrotic eruptions revealed marked epidermal necrosis, perivascular lymphocytic infiltrates and epidermotropic infiltration of lymphocytes showing markers of CD3(+) lymphocytes (90-95% of all infiltrating cells), CD4(+) (40-50%), CD8(+) (40-50%), and CD45RO(+) (70%). In contrast, the BCG vaccination site revealed intradermal granuloma with epithelioid cells, occasional giant cells and infiltration of lymphocytes consisting of CD3(+) (60-70%), CD4(+) (40-50%), CD8(+) (30-40%), CD45RO(+) (40%), CD79a(+) (30-40%), and CD20(+) (20-30%). Our patient did not reveal any signs indicative of tuberculosis. Papulonecrotic lesions were therefore called papulonecrotic tuberculid-like eruptions, rather than tuberculids, that occurred after BCG vaccination and appeared to derive from a hypersensitive reaction mediated by immune lymphocytic infiltration.

Basic fibroblast growth factor in an artificial dermis promotes apoptosis and inhibits expression of ?-smooth muscle actin, leading to reduction of wound contraction

To clarify the mechanisms underlying declines in wound contraction caused by basic fibroblast growth factor (bFGF) and the role of autologous fibroblasts in modulating wound healing, we have examined the expression of alpha-smooth muscle actin (alpha-SMA) and apoptosis in a model of wound healing using collagen sponges with and without bFGF (1 microg) and/or fibroblasts (1 x 10(6) cells/cm(2)) applied to experimentally produced full-thickness skin wounds in rats (n=10 for each group). At 7 days postoperatively, wounds filled with a fibroblast-seeded collagen sponge (fibroblast-seeded group) displayed a greater area of collagen sponge and a smaller area of fibroblasts compared with control wounds filled with collagen sponge alone (control group). Therefore, seeding of fibroblasts in the dermal substitute might retard degradation of the collagen sponge, inhibiting fibroblast infiltration into the substitute. By day 14, wounds filled with bFGF-treated collagen sponge without fibroblast seeding (bFGF group) displayed decreased alpha-SMA expression and significantly increased apoptosis compared with other wounds. Double staining revealed that apoptosis in alpha-SMA-positive fibroblastic cells was significantly increased in the bFGF group, suggesting that bFGF treatment is a potent stimulator of myofibroblast apoptosis. Furthermore, morphometric analysis demonstrated the significant decrease in the level of wound contraction and the degree of mature collagen bundle formation in the bFGF group by day 42. The bFGF group also showed increased bFGF expression in macrophages by day 28. These results suggest that bFGF administration to an artificial dermis promotes apoptosis of alpha-SMA-positive fibroblastic cells and inhibits alpha-SMA expression in the treated wound, thus reducing wound contraction.

Diacylglycerol kinase α suppresses tumor necrosis factor-α-induced apoptosis of human melanoma cells through NF-κB activation

We investigated the implication of diacylglycerol kinase (DGK) alpha (type I isoform) in melanoma cells because we found that this DGK isoform was expressed in several human melanoma cell lines but not in noncancerous melanocytes. Intriguingly, the overexpression of wild-type (WT) DGKalpha, but not of its kinase-dead (KD) mutant, markedly suppressed tumor necrosis factor (TNF)-alpha-induced apoptosis of AKI human melanoma cells. In the reverse experiment, siRNA-mediated knockdown of DGKalpha significantly enhanced the apoptosis. The overexpression of other type I isoforms (DGKbeta and DGKgamma) had, on the other hand, no detectable effects on the apoptosis. These results indicate that DGKalpha specifically suppresses the TNF-alpha-induced apoptosis through its catalytic action. We found that the overexpression of DGKalpha-WT, but not of DGKalpha-KD, further enhanced the TNF-alpha-stimulated transcriptional activity of an anti-apoptotic factor, NF-kappaB. Conversely, DGKalpha-knockdown considerably inhibited the NF-kappaB activity. Moreover, an NF-kappaB inhibitor blunted the anti-apoptotic effect of DGKalpha overexpression. Together, these results strongly suggest that DGKalpha is a novel positive regulator of NF-kappaB, which suppresses TNF-alpha-induced melanoma cell apoptosis.

4-S-Cysteaminylphenol-loaded magnetite cationic liposomes for combination therapy of hyperthermia with chemotherapy against malignant melanoma

Tyrosine analogs are good candidates for developing melanoma chemotherapies because melanogenesis is inherently toxic and expressed uniquely in melanocytic cells. The sulfur homolog of tyrosine, 4-S-cysteaminylphenol (4-S-CAP), was shown to be a substrate of melanoma tyrosinase and can cause selective cytotoxicity of melanocytes and melanoma cells. Previously, in order to improve the adsorption of magnetite nanoparticles to target cell surfaces, and generate heat in an alternating magnetic field (AMF) for cancer hyperthermia, we produced hyperthermia using magnetite cationic liposomes (MCL) that have a positive charge at the liposomal surface. In the present study, we constructed 4-S-CAP-loaded MCL (4-S-CAP/MCL), which act as a novel modality, combining melanoma-specific chemotherapy by 4-S-CAP with intracellular hyperthermia mediated by MCL. The 4-S-CAP/MCL exerted 4-S-CAP-mediated anticancer effects on B16 melanoma cells in vitro and in vivo. Moreover, after intratumoral injection of 4-S-CAP/MCL in vivo, the melanoma nodules were heated to 45 degrees C under an AMF. Significantly higher therapeutic effects were observed in mice treated with the combination therapy mediated by 4-S-CAP/MCL plus AMF irradiation compared with mice treated with 4-S-CAP/MCL alone (without AMF) or mice treated with hyperthermia alone (MCL + AMF irradiation). These results suggest that this novel therapeutic tool is applicable to the treatment of malignant melanoma.

CD30+ large cell transformation of mycosis fungoides after psoralen plus ultraviolet A photochemotherapy

Psoralen plus ultraviolet A (PUVA) photochemotherapy is widely used for the therapy of mycosis fungoides (MF). Clinical progression of MF is often associated with an increase in the size of tumour cells known as transformation. We report two patients with CD30+ large cell transformation that appeared after low-dose PUVA therapy for MF. Clinical data, histopathology, immunohistopathology and T-cell receptor gene rearrangement were studied. Nodules consisted of atypical large cells that expressed CD30. Monoclonal rearrangement of T-cell receptors was observed in one case. Low-dose PUVA therapy may be associated with CD30+ large cell transformation in patients with MF.

The real-time, three-dimensional analyses of benign and malignant skin tumors by confocal laser scanning microscopy

BACKGROUND

In obtain images of skin tumors non-invasively with real-time, confocal laser scanning microscope (CLSM) is introduced.

OBJECTIVE

Reconstructed images of given horizontal sections were converted into three-dimensions using the data set of a large number of tomograms in the horizontal directions.

METHODS

To develop the multiplaner reconstruction images of skin tumors in vertical directions and three-dimensionally reconstructed images of tumors will be obtained from the continuously collected horizontal image data sets.

RESULTS

Three-dimensional analyses of the skin tumors from reconstructed images of the CLSM scanning have provided the information as to their physiological characteristics as well as the extent of deep invasion in real-time with non-invasive manner. High performance three-dimensional conversion software was effective in displaying three-dimensional construction of skin tumors.

CONCLUSION

The CLSM scanning images followed by three-dimensional reconstruction using them can provide the real-time and non-invasive diagnoses of skin tumors and analyze the radial growth phase of tumors and the three-dimensional growth characteristics.

Biological monitoring of solar UV radiation at 17 sites in Asia, Europe and South America from 1999 to 2004

A small and robust dosimeter for determining the biologically effective dose of ambient UV radiation has been developed using UV-sensitive mutant spores of Bacillus subtilis strain TKJ6312. A membrane filter with four spots of the spores was snapped to a slide mount. The slide was wrapped and covered with two or more layers of polyethylene sheet to protect the sample from rain and snow and to reduce monthly-cumulative doses within the measurable range. From 1999, monthly data were collected at 17 sites for more than 1 year, and data for 4 to 6 consecutive years were obtained from 12 sites. Yearly total values of the spore inactivation dose (SID) ranged from 3200 at subarctic Oulu to 96 000 at tropical Denpasar, and the mean yearly values of SID exhibited an exponential dependence on latitude in both hemispheres with a doubling for about every 14 degrees of change. During the observation period, increasing trends of UV doses have been observed at all sites with more than 5 years of data available. Year-to-year variations at high and middle latitude sites are considered due mostly to climatic variation. At three tropical sites, negative correlations between the yearly doses and the column ozone amounts were observed. The results verified the applicability of spore dosimetry for global and long-time monitoring of solar UV radiation, in particular at tropical sites where no monitoring is taking place.

Reconstruction method with a newly-designed bilobed flap after excision of tumours of the skin

We have devised a bilobed skin flap for reconstruction after excision of small skin tumours. The sutured part serves as a zig-zag that leads to only slight postoperative contracture of the scar. The rotation centre of the flap is nearer to the affected area than other conventional bilobed flaps, resulting in less dog-ear deformity and distortion of tissue.

Mechanism of the immunosuppressive effect in vivo of novel immunosuppressive drug beta-SQAG9, which inhibits the response of the CD62L+ T-cell subset

INTRODUCTION

We synthesized sulfo-glycolipid, beta-SQAG9 (designate square beta-SQAG9 liposome, because it efficiently forms a liposome structure) that possessed immunosuppressive effects such as inhibition of T-cell responses in human allogeneic MLR and skin allograft survival in rats, and bound to CD62L (L-selectin) in vitro. In this study, we further investigated the immunosuppressive mechanism in vivo by beta-SQAG9 liposome in a skin-allografted rat model.

METHODS

ACI rats (RT1(a)) were grafted skin of LEW rats (RT1(1)) treated with PBS or beta-SQAG9 liposome IV once a day for 7 days. Subsequently, we investigated the population of T cells and CD62L(+) T-cell subset in the spleen, axillary lymph nodes (ALNs), and peripheral blood of skin-allografted rats by two-color flow cytometry.

RESULTS

Five of 11 (45.5%) rats that were treated with 50 mg/kg beta-SQAG9 liposome showed graft survival and another showed moderate rejection in graft. The CD62L(+) T-cell subset population in ALNs of beta-SQAG9 liposome-treated rats decreased in a dose-dependent manner. No significant difference in the T-cell population was observed between the beta-SQAG9 and control groups. These data suggest that beta-SQAG9 could bind to the CD62L(+) T-cell subset in vivo as well as in vitro and affect T-cell migration, which might lead to T-cell tolerance in vivo.

Inhibition of CD62L+ T-cell response in vitro via a novel sulfo-glycolipid, beta-SQAG9 liposome that binds to CD62L molecule on the cell surface

We previously reported that synthetic sulfo-glycolipid, 3-O-(6-deoxy-6-sulfono-beta-D-glucopyranosyl)-1,2-di-O-acylglycerol (beta-SQDG(18:0)) which was deduced from sulfonoquinovosyl-diacylglycerols of sea urchin possessed immunosuppressive effects, such as human mixed lymphocyte reaction (MLR) and skin allograft in rat, and that these effects were caused by contact inhibition between T-cells and antigen presenting cells (APCs). Here, we investigated the mechanism of these immunosuppressive effects on human MLR by beta-SQAG9 which had been newly synthesized from beta-SQDG(18:0) to improve structural stability in water solution. CD62L+ T-cells in peripheral blood predominantly respond to APCs, and beta-SQAG9 inhibited the response of CD62L+ T-cell subset in human allogeneic MLR. Surprisingly, it was demonstrated that beta-SQAG9 bound to L- and P-selectin (CD62L and P) molecule in vitro. Meanwhile, beta-SQAG9 efficiently formed liposome structure and bound to L-selectin on the cell surface of CD62L+ T-cell subset but might not be incorporated into the cells. Because the immunosuppressive effects of beta-SQAG9 disappeared when beta-SQAG9 liposome was changed to soluble form by detergent, the liposome structure of beta-SQAG9 was presumed to be essential for these effects. These findings suggested beta-SQAG9 to be a novel drug with a unique immunosuppressive action.

Combination of porous hydroxyapatite and cationic liposomes as a vector for BMP-2 gene therapy

The clinical significance of hydroxyapatite (HAP) as a bone substitute has become apparent in recent years and bone morphogenetic protein (BMP) a substance which induces bone has attracted much attention. In this study, a 1.2 cm diameter bone defects created on rabbit cranium were treated with the BMP-2 gene (cDNA plasmid) introduced with porous HAP after completion of hemostasis and the resultant bone formation was analyzed histopathologically. The amounts of bone formation was compared BMP-2 cDNA plasmids were not combined with cationic liposomes as a vector. Four groups of rabbits were compared. In the HAP group the cranial bone defect was treated with HAP containing 40 microg of liposomes and a dummy gene (PU). The BMP gene HAP group was treated with HAP soaked in liposomes and 10 microg of the BMP-2 gene. In addition, a group was treated with the gene without implanting HAP. Bone formation on the cranial defects was evaluated 3, 6 and 9 weeks after the operation, by X-ray and histopathological examinations. Three weeks after the operation there was vigorous bone formation in the cranial defect in the group which received the BMP-2 gene without HAP, and complete ossification was observed at 9 weeks. In the group which received HAP containing the BMP-2 gene, although new bone formation was evident surrounding the scaffold 3 weeks post-operation, the induced bone tissue did not fill all the pores of the scaffold even at 9 weeks post-operation. These results confirm the clinical usefulness of gene therapy for bone formation, using the BMP-2 gene combined with cationic liposomes as a vector. It is possible that the effects of administering the BMP-2 gene will be improved by specializing the microstructure of scaffold for gene therapy.

Tyrosinase-related proteins suppress tyrosinase-mediated cell death of melanocytes and melanoma cells

The synthesis of melanin intermediates through tyrosinase (TYR) involves the production of cytotoxic free radicals. By using recombinant adenoviruses that express TYR, tyrosinase-related protein 1 (TYRP1) or DOPAchrome tautomerase (DCT), we analyzed the biological function of these proteins with regard to melanin production and the growth of melanocytes, fibroblasts, melanoma cells and nonmelanoma cancer cells. High-level expression of TYR produced newly synthesized melanin and induced cell death in all of these cells. However, when TYRP1 or DCT was coexpressed with TYR in melanocytes and melanoma cells, TYR-mediated cell death was clearly decreased. This decrease was not observed in nonmelanocytic cells. Western blot analysis and measurement of enzyme activity revealed that the expression of TYRP1 or DCT had little effect on the amount or activity of cointroduced TYR in either the melanocytic or nonmelanocytic cells. In cells expressing both TYR and TYRP1 or TYR and DCT, the total amount of melanin and/or eumelanin increased substantially more than that in cells expressing TYR alone. On the other hand, the level of pheomelanin was similar in these three cell types. These findings suggest that TYRP1 and DCT play an important role in suppressing TYR-mediated cytotoxicity in melanocytic cells without decreasing TYR expression and/or activity. These biological activities of TYRP1 and DCT may work through the interaction with TYR in melanosomal compartment.

Ectopic expression of tyrosinase increases melanin synthesis and cell death following UVB irradiation in fibroblasts from familial atypical multiple mole and melanoma (FAMMM) patients

Patients with familial atypical multiple mole and melanoma (FAMMM) [so-called familial dysplastic naevus syndrome (FDNS)] have a high risk for the development of malignant melanoma. The underlying gene defect has an autosomal dominant inheritance with variable expression and incomplete penetrance. Fibroblasts derived from FAMMM patients have high sensitivity to UVC and mutagens, e.g. 4-nitroquinoline-1-oxide. We were interested in identifying how the combination of inherent sensitivity to UV light and abnormal melanin synthesis interacts in the development of melanoma in FAMMM patients. Intermediates of melanin synthesis produce free radicals that are toxic to cells. Atypical moles (dysplastic naevi) are engaged in the biosynthesis of abnormal melanin pigments. This study examined whether there was any abnormal melanin pigmentation or cell damage after the ectopic expression of tyrosinase in fibroblasts from FAMMM patients when compared with fibroblasts from normal subjects. Fibroblasts from FAMMM patients (3012T and 3072T) were associated with a higher sensitivity than normal human fibroblasts to the toxicity of UVB. When cells were infected with tyrosinase-expressing adenovirus (Ad-HT) and irradiated with UVB, FAMMM fibroblasts showed higher tyrosinase activity, produced more melanin pigments and were degraded more significantly than normal human fibroblasts. Western blot analysis revealed that Ad-HT-infected 3072T produced a larger amount of tyrosinase protein than did Ad-HT-infected normal fibroblasts after UVB irradiation. Our findings suggest: (1) that FAMMM fibroblasts have an unknown machinery which enhances tyrosinase expression by UVB irradiation; and (2) that the resulting increase in melanin synthesis affects the cytotoxicity of UVB to FAMMM fibroblasts. All of these processes may be involved in the genomic instability and development of melanoma in FAMMM patients.

Local administration of hepatocyte growth factor gene enhances the regeneration of dermis in acute incisional wounds

Hepatocyte growth factor (HGF) has a number of biological activities, e.g., mitogenic, motogenic, antiapoptotic, antifibrous, and morphogenic. It also has angiogenic and angioprotective activities for endothelial cells. The aim of this study was to characterize the role of HGF in wound healing by administering the HGF gene locally to acute incisional skin wounds created on the backs of rats. To create wounds, the backs of Wistar rats were clipped and three 2-cm-long incisional wounds were made deep to the fascia. The wounds contained pannicrus carnosum and were created at intervals of 2 cm. After suturing, the HGF gene was then administered intradermally. Apoptotic cells in wound lesions were identified by TUNEL method as well as by immunological detection of active caspase-3. In the HGF-treated animals, we found almost complete suppression of apoptosis and well-organized wound healing. Histopathological examination revealed that the proliferation of fibroblasts was suppressed and that scar formation was less apparent in the HGF-treated animals compared to the controls. It is thought that administration of the HGF gene immediately after surgery may enhance the healing process through suppressing apoptosis, which occurred in the controls 1 week after suturing the incisional wound. In addition, locally increased HGF expression due to the introduction of the HGF gene to cells around wounds enhances dermal regeneration, possibly by promoting regeneration of dermal tissue, which results in less scarring due to its antifibrotic effect. Thus, HGF supplementation through gene therapy may be an effective strategy for treating wounds, as it increases the regeneration of the dermis to allow for "scarless wound healing."

Basic fibroblast growth factor promotes apoptosis and suppresses granulation tissue formation in acute incisional wounds

Cytokines are thought to play an important role in cellular loss and apoptosis during the repair of granulation tissue. In order to investigate the role of apoptosis following the administration of basic fibroblast growth factor (bFGF) to a wound, the present study examined the relationship between the degree of granulation tissue formation and the level of apoptosis in rat skin incisional wounds, following treatment with an intradermal injection of bFGF (0.1 microg and 1 microg per cm of wound). Histological assessment of the width of the wound tissue showed that the degree of granulation tissue in the 1 microg-bFGF-treated group had increased by day 7, but then subsequently diminished by days 14 and 28. The TUNEL index increased rapidly from day 1, peaking on day 7, with the index being higher in the 1 microg-bFGF-treated group on days 4, 7, and 14, when compared with a control group. In parallel with a marked increase in the TUNEL index over the first 14 days, the number of cells positive for vimentin and CD3 in the 1 microg-bFGF-treated wounds had decreased by day 14. The number of PCNA-positive cells, an indicator of cell proliferation, peaked on day 4 in the bFGF-treated wounds and then declined rapidly. On the basis of these results, it is suggested that the suppression of granulation tissue formation in bFGF-treated wounds is mainly due to an early and persistent increase in apoptosis in the granulation tissue cells. The expression of both transforming growth factor (TGF)-beta1 and bFGF was also elevated in the bFGF-treated wounds on days 4 and 7, suggesting that fibroblast apoptosis was induced by bFGF treatment. Unexpectedly, on day 28, the wound breaking strength was not reduced in the bFGF-treated wounds. These results indicate that apoptosis regulation following bFGF administration to an incisional wound may lead effectively to granulation tissue formation and promote a scar-less repair process.

Induction of suppressor of cytokine signaling-3 by herpes simplex virus type 1 contributes to inhibition of the interferon signaling pathway

We showed previously that herpes simplex virus type 1 (HSV-1) suppresses the interferon (IFN) signaling pathway during the early infection stage in the human amnion cell line FL. HSV-1 inhibits the IFN-induced phosphorylation of Janus kinases (JAK) in infected FL cells. In the present study, we showed that the suppressor of cytokine signaling-3 (SOCS3), a host negative regulator of the JAK/STAT pathway, is rapidly induced in FL cells after HSV-1 infection. Maximal levels of SOCS3 protein were detected at around 1 to 2 h after infection. This is consistent with the occurrence of HSV-1-mediated inhibition of IFN-induced JAK phosphorylation. The HSV-1 wild-type strain VR3 induced SOCS3 more efficiently than did mutants that are defective in UL41 or UL13 and that are hyperresponsive to IFN. Induction of the IRF-7 protein and transcriptional activation of IFN-alpha4, which occur in a JAK/STAT pathway-dependent manner, were poorly induced by VR3 but efficiently induced by the mutant viruses. In contrast, phosphorylation of IRF-3 and transcriptional activation of IFN-beta, which are JAK/STAT pathway-independent process, were equally well induced by the wild-type strain and the mutants. In conclusion, the SOCS3 protein appears to be mainly responsible for the suppression of IFN signaling and IFN production that occurs during HSV-1 infection.

Idiopathic acquired generalized anhidrosis due to occlusion of proximal coiled ducts

Idiopathic acquired generalized anhidrosis is a very rare disease of unknown pathogenesis. We report a 25-year-old man with acquired generalized anhidrosis due to occlusion of the coiled ducts. He did not have sweat secretion over the entire surface of the body, including the palms and soles. Sweat-inducing stimuli provoked tingling pain on the skin. Pilocarpine iontophoresis on the forearm did not induce sweat secretion. Neurological examination did not reveal any abnormality in the central or peripheral nervous system. Skin biopsy showed that the coiled ducts were occluded by an amorphous eosinophilic substance. This amorphous eosinophilic substance was positive with periodic acid-Schiff (PAS) staining and was resistant to digestion by diastase. Electron microscopy demonstrated that the coiled ducts were completely occluded by an amorphous substance. The substance occluding the coiled ducts contained fibrous structures. These findings suggested that the acquired generalized anhidrosis in this patient was caused by occlusion of the coiled ducts by a PAS-positive substance probably derived from dark cell granules.