Establishment and characterization of a cell line (DEOC-1) originating from a human malignant melanoma of the skin

A new human malignant melanoma cell line, designated DEOC-1, was established from the heel lesion of a 59-year-old man. This cell line has grown well for 84 months. The monolayer, cultured cells are polygonal in shape, appear to be spindle-shaped cells or multipolar cells, and have a tendency to pile up without contact inhibition. The cells are aneuploid, and the modal chromosomal number is in the hyper-triploid range. The cells were transplanted into the subcutis of SCID mice and produced tumors resembling the original tumor. The DEOC-1 cells (1 x 10(6)/5 mL) produced 5-S-cysteinyldopa (5-S-CD). The cells were not sensitive in vitro to any anticancer drug currently used for the treatment of malignant melanoma. Increases in both the protein and the transcriptional levels (mRNA) of multidrug resistance-related genes (multidrug resistance gene 1, multidrug resistance-associated protein 1 and lung resistance-related protein) were observed in DEOC-1 cells. The DEOC-1 cells are well characterized and are a very useful material for basic research of malignant melanoma.

Real-TimeReflectance Confocal Microscopy, a Noninvasive Tool for in vivo Quantitative Evaluation of Comedolysis in the Rhino Mouse Model

BACKGROUND

Near-infrared reflectance confocal microscopy (RCM) is a noninvasive tool that provides real-time images of thin virtual horizontal tissue sections.

AIMS/METHODS

We have used a rhino mouse model in combination with topical application of all-trans-retinoic acid and all-trans-retinol to investigate the usefulness of RCM as a noninvasive imaging tool to evaluate comedolysis in vivo and over time. Optical images were correlated with routine histology.

RESULTS

Our results demonstrate that RCM in vivo can visualize the process of transformation of utriculi (pseudocomedones) towards a normal-appearing follicular structure during retinoid treatment. The retinoic acid intervention group showed a dose-related response, while the vehicle-treated group did not show utricular changes.

CONCLUSIONS

RCM represents a useful tool for in vivo morphological and quantitative evaluation of skin utriculi over time and could be used as an adjunct tool to histopathological techniques for comedolysis studies.

Downregulation of TGFbeta isoforms and their receptors contributes to keratinocyte hyperproliferation in psoriasis vulgaris

BACKGROUND

Psoriasis vulgaris is a chronic inflammatory disorder characterized by epidermal hyperproliferation. Transforming growth factor beta (TGFbetas) have a major antiproliferative action in epidermis.

OBJECTIVE

We evaluated the distribution and levels of expression of TGFbeta isoforms and their receptors in psoriatic versus normal skin with the goal of discovering potential alterations in TGFbeta signal transduction associated with psoriasis.

METHODS

Expression of TGFbeta isoforms and their receptors was analyzed in normal and psoriatic skin using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques. Furthermore, DNA synthesis was measured in normal keratinocytes transfected with a dominant-negative TGFbeta receptor II (TbetaRII) vector that eliminated most of the cytoplasmic TbetaRII domain.

RESULTS

Marked elevations in DNA synthesis, as assessed by BrdU incorporation and proliferating cell nuclear antigen (PCNA) immunoreactivity, were confirmed in psoriatic epithelial cells. Using immunohistochemistry and RT-PCR analysis, expression of TGFbeta2 and 3 was diminished in the psoriatic epidermis as compared with those observed in normal skin. With respect to TGFbeta receptors, expression of TbetaRI and II was markedly decreased in the psoriatic epidermis. In addition, levels of Smad2 mRNA were also decreased in psoriatic skin. Transfection of normal keratinocytes with the dominant-negative TbetaRII vector significantly elevated DNA synthesis as compared with keratincoytes transfected with control vector (under condition of TGFbeta addition), suggesting that the dominant-negative TbetaRII mutant inhibits the antiproliferative effects of TGFbeta.

CONCLUSION

The present investigation strongly suggest that the TGFbeta signaling pathway is downregulated in psoriatic skin and this situation leads to abnormal cell proliferation due to a functional decrease in growth regulation.

A case of syringocystadenocarcinoma papilliferum in situ occurring partially in syringocystadenoma papilliferum

We report a case of syringocystadenocarcinoma papilliferum in situ associated with syringocystadenoma papilliferum. The patient was a 64-year-old man with a red tumor that arose on top of his head two years before he consulted our department. The histological findings revealed a papillomatous growth on the epidermis forming several invaginations. Numerous papillary projections, lined by a two-layered epithelium with a benign appearance and decapitations on the luminal surface of the cells, extended into the lumens of the invaginations. Some projections showed a disorderly arrangement of multilayered cells with atypical nuclei. No differences between findings in the syringocystadenocarcinoma papilliferum in situ and those in the syringocystadenoma papilliferum were observed histochemically (PAS) or immunohistochemically (cytokeratin, CEA, CA 19-9, S-100, gross cystic disease fluid protein, lysozyme and Leu M1).

Characterization of nociceptin/orphanin FQ-induced pain responses by the novel receptor antagonist N-(4-amino-2-methylquinolin-6-yl)-2-(4-ethylphenoxymethyl) benzamide monohydrochloride

At the spinal level, nociceptin/orphanin FQ (Noc/OFQ) produces pronociceptive and allodynic effects at low doses (picogram range), while causing antinociceptive effects at high doses (microgram range). The discrepancy of pain modulation by Noc/OFQ at low and high doses raised a question whether Noc/OFQ exerted actions through the same Noc/OFQ receptor. In the present study, we examined the involvement of the Noc/OFQ receptor in pain responses with the novel nonpeptide antagonist N-(4-amino-2-methylquinolin-6-yl)-2-(4-ethylphenoxymethyl) benzamide monohydrochloride (JTC-801). Allodynia and hyperalgesia evoked by intrathecal administration of Noc/OFQ (50 pg/mouse) were dose dependently blocked by simultaneous administration of JTC-801 with IC(50) values of 32.2 and 363 pg, respectively. JTC-801 did not induce allodynia by itself. Subcutaneous injection of formalin into a hindpaw evoked biphasic pain behaviors such as flinching and biting in mice. Noc/OFQ at 10 pg increased the second-phase pain behaviors evoked by 1% formalin, whereas it strongly inhibited both the first-phase and second-phase pain evoked by 2% formalin at 1 microg. Although the pronociceptive effect by 10 pg of Noc/OFQ was dose dependently blocked by JTC-801 with an IC(50) value of 4.58 pg, the antinociceptive effects by 1 microg of Noc/OFQ were not antagonized by JTC-801. Furthermore, both phases of 2% formalin-induced pain behaviors were relieved by JTC-801. These results demonstrate that pronociceptive responses induced by a low dose of Noc/OFQ may be mediated through the Noc/OFQ receptor in the spinal cord and that JTC-801 can be a useful antagonist to examine the involvement of endogenous Noc/OFQ and mediation of the Noc/OFQ receptor under physiological and pathophysiological conditions including pain.

Polymorphisms of p21 cyclin-dependent kinase inhibitor and malignant skin tumors

Polymorphisms of the cyclin-dependent kinase inhibitor gene p21 have recently been reported to be associated with several human cancers. To determine whether the polymorphisms are also associated with human skin cancers, we investigated the p21 polymorphisms in 165 healthy Japanese and 113 Japanese with malignant skin tumors: 30 squamous cell carcinoma, 20 malignant melanoma, 33 basal cell carcinoma, and 30 Bowen's disease. The p21 polymorphisms were characterized by single base substitutions in the following two sites: the last nucleotide of codon 31 of exon 2 and the site 20 nucleotides downstream from the 3' end of exon 3. The two polymorphic sites were reported to be firmly linked to each other. We have shown that the two sites were firmly linked to each other also in Japanese and that no associations of the polymorphisms with the skin cancers in Japanese were detected by statistical analysis. Although the p21 polymorphisms were found not to be involved with skin carcinogenesis, ethnic differences of the allele frequency distribution must be taken into account in studying the role of the p21 polymorphism in carcinogenesis.

Expression of lung resistance protein in epithelioid sarcoma in vitro and in vivo

The incidence of epithelioid sarcoma among patients with malignant soft tissue tumors is small, but the rates of recurrence and metastasis of this type of sarcoma are high. To date, effective chemotherapy for advanced epithelioid sarcoma has not been established and, furthermore, epithelioid sarcoma is known to exhibit multidrug resistance (MDR). The chemosensitivities to anticancer agents of two cell lines established from epithelioid sarcoma were examined in this study. The results showed that the ES-OMC-MN and SFT-8606 cell lines were resistant to vincristine (IC50 1190 nM and 872 nM, respectively) and Adriamycin (IC50 921 nM and 650 nM, respectively), but sensitive to actinomycin D (IC50 < 10 nM). P-glycoprotein (p-Gp) and MDR-associated protein (MRP) were not expressed in these cell lines, but a high expression level of lung resistance protein (LRP) was observed. The original tumor tissues from which the two cell lines were established were also found to be LRP-positive but not to express p-Gp or MRP. Their chemosensitivities to Adriamycin were not significantly altered in the presence of 2.5 microg/ml anti-LRP antibody (LRP-56), but the IC50 of vincristine was much less (IC50 128 nM and 27 nM, respectively) than that for an untreated cell line. It is thus suggested that the vincristine resistance in the two cell lines is LRP-mediated. Since cyclosporin A, known to be a modifier of p-Gp, also induced reversal of vincristine resistance in the ES-OMC-MN and SFT-8606 cell lines (IC50 6.2 nM and 17 nM, respectively), it is suggested that cyclosporin A acts as a modifier of MDR mediated by LRP.

Acute monocytic leukemia presenting as cutaneous involvement

Specific cutaneous lesions appearing during acute monocytic leukemia (AMoL) are more frequent than those associated with other types of leukemia. However, skin involvement preceding the presence of leukemic cells in the peripheral blood is quite rare. In this paper, we describe a case where a 25-year-old male had multiple infiltrative erythemas and nodules on his arms. Histologically, the nodules were formed by masses of tumor cells in the dermis. Peripheral-blood tests revealed no abnormalities, but bone marrow aspiration from the sternum led to a diagnosis of AMoL. The diagnosis of specific cutaneous lesions of AMoL was confirmed by the results of cytochemical studies of bone marrow smears, and cutaneous nodules of cutaneous biopsy specimens led to early diagnosis. Complete remission was achieved with combination chemotherapy and peripheral blood stem cell transplantation.

Diffuse cutaneous mastocytosis responding to cyproheptadine

A 3-month-old male infant was referred to our department with a generalized brown, thickened leathery skin and blisters which had been present since birth; the blisters developed recurrently at sites of minor trauma, healing without scar formation, although Darier's sign was positive. Microscopically, biopsy specimens showed a dense dermal band-like infiltrate with mast cells, whereas a biopsy from a vesicle showed subepidermal bulla formation. Physical examination did not reveal any systemic involvement with mastocytosis and the patient was treated with cyproheptadine, which has considerable anti-serotonin activity and, interestingly, reduced the degree of blistering; this treatment might therefore be tried in other cases.

p53 gene mutations in squamous cell carcinoma occurring in scars: comparison with p53 protein immunoreactivity

We determined the relationship between p53 expression and p53 gene mutations in squamous cell carcinoma occurring in scars and unrelated to UV light irradiation. We analyzed biopsy specimens obtained from three patients with squamous cell carcinoma. A monoclonal antibody against p53 (DO-7) was used for the immunohistochemical analysis. p53 gene mutations were detected by the polymerase chain reaction and single-strand conformation polymorphism analysis and direct DNA sequencing. p53 overexpression was observed in atypical squamous cells of one case. Those of two other cases, however, showed negative immunoreactivity to p53. Exon 6 of the p53 gene in all three cases and exon 7 in one case showed electrophoretic mobility shifts in polymerase chain reaction and single-strand conformation polymorphism analysis. DNA sequencing analysis showed a missense mutation and a silent mutation in exon 6 of the case with p53 overexpression, a three-base deletion in exon 6 of one case with no p53 overexpression, and a three-base deletion in exon 6 and a missense mutation in exon 7 of another such case. Although immunohistochemical overexpression of p53 has been thought to result from p53 gene mutations, our results suggest that negative immunoreactivity to p53 also can result from p53 gene mutations, for example, short gene deletions.

Epidermal growth factor binding sites in the mouse exocrine and endocrine pancreas shown by in vivo quantitative microautoradiography and confocal laser scanning microscopy

Microautoradiography at 3, 6 and 15 min after intravenous injection of 125I-EGF was used to investigate the distribution of epidermal growth factor (EGF) binding sites in the pancreas of normal male mice. The autoradiographs were observed by confocal laser microscopy, which allows the quantification of silver grains. The results demonstrated that both endocrine and exocrine pancreatic cells exhibited substantial specific binding of 125I-EGF. The highest level of EGF binding was found in the duct cells of the exocrine pancreas followed by the acinar cells. The cells of the islets of Langerhans also showed substantial specific binding of 125I-EGF though the binding level was lower than that of the exocrine pancreas. In the control experiments, mice were injected with 125I-EGF and various amounts of unlabeled EGF.

Establishment and characterization of an epithelioid sarcoma cell line with an autocrine response to interleukin-6

A novel epithelioid sarcoma (ES) cell line, designated as ES-OMC-MN, was established from a 44-year-old woman with recurrence and metastasis of ES. The cells were spindle-shaped or polygonal and were positive for cytokeratin and vimentin on immunohistochemical staining. Electron microscopy revealed desmosome-like structures between the cells. These characteristics were also noted in the original tumor. Southern blot analysis of HindIII digests showed an additional 8.0 kb band and an 8.8 kb band in DNA from the cultured cells and the original tumor as well as the peripheral blood cells of the patient, while only an 8.8 kb band was observed in control human placental DNA. There were no point mutations of N-ras codons 12, 13, and 61, suggesting that the abnormality of N-ras was not due to mutation but to polymorphism. Interleukin-6 (IL-6) was secreted into the culture medium at high levels. Recombinant IL-6 augmented the proliferation of these cells, while cell growth was inhibited by incubation with an anti-IL-6 antibody. The cells also expressed surface IL-6 receptors, indicating that IL-6 acted on this cell line in an autocrine manner. IL-6 and IL-6 receptors were also found in the original tumor. These results demonstrate that ES-OMC-MN cells retained all the morphological and biochemical characteristics of the original tumor and suggest that an autocrine effect of IL-6 may be involved in the development of ES.

In vivo microradioautographic study of insulin binding in the skin of normal and NIDDM mice: with special reference to acanthosis nigricans

Insulin bindings in the tissues and cells in the skin of non-diabetic (control) and genetically diabetic db/db (NIDDM) mice were investigated by in vivo microradioautography at 3 and 15 min. after intravenous injection of 125I-insulin. Specific insulin bindings were observed in the interfollicular epidermis, infundibulum, dermis, outer root sheath, sebaceous glands and blood vessels, but not in the hair shaft of the control mice. Although the specific bindings were seen in the interfollicular epidermis, infundibulum, outer root sheath and blood vessels in the NIDDM mice, the bindings were much less than those of the control mice at both 3 and 15 min. after 125I-insulin injection with an exception of the blood vessels at 3 min. The possible relationships between NIDDM and acanthosis nigricans from the viewpoint of insulin binding are considered.

The presence of h2-calponin in human keratinocyte

Calponin (h1 isoform) was characterized as a smooth muscle specific, actin-, tropomyosin-, calmodulin-binding protein and described as a factor which inhibits contraction. H2-calponin, encoded by a different gene from h1-calponin, was identified from the smooth muscles of mouse and pig. However, non-muscle calponin analogues have recently been reported in rat and pig brains. Here we show the presence of calponin expressed in human skin tissue and in cultured human keratinocytes using polyclonal antibodies to bovine aortic smooth muscle calponin. Western blot analysis demonstrated that calponin with a molecular weight around 36,000 existed in extracts of keratinocytes. Immunofluorescence microscopy displayed the localization of calponin in the cytoplasm of the basal cells in situ, and along the cell-to-cell borders in cultured human keratinocytes maintained in standard calcium medium. Furthermore, according to RT-PCR analysis using human h1- and h2-calponin-specific primers, calponin expressed by cultured human keratinocytes was identified as the h2 isoform. We demonstrated the presence of h2-calponin in human keratinocytes, and it might play a role in the structural organization of actin cytoskeleton at the cytoplasmic region of cell-to-cell junctions of keratinocytes.

Distribution of [1,2-3H]taurine in the skin of adult and newborn mice studied by microradioautography

In vivo light microscopic radioautography was used to demonstrate the distribution of taurine in adult and newborn mice at 30 min. and 3 hrs. after the injection of 3H-taurine. This study showed that the injected taurine was present in free form in the skin. Radioautographically, it was found that in the adult a very high density of taurine was found over the epidermis and external root sheaths near the opening of the hair follicles. The external root sheath just below the insertion of the sebaceous glands and the peripheral part of the sebaceous glands showed a high taurine distribution. Connective tissue in the dermis, however, showed low uptake of taurine. In the neonate mouse, the density of injected taurine in both the epidermis and the external root sheath was lower than that the density in the connective tissue in the dermis. We report these findings in detail and discuss some of the functional roles of taurine in the skin.

Metastatic epithelioid sarcoma with an N-ras oncogene mutation

At age 25 a Japanese woman noticed an elastic-hard nodule 2 cm in diameter on the anterior side of her right leg. The nodule had developed an ulcer in its center. Simple resection was performed several times. However, the lesion recurred repeatedly. The patient underwent amputation of the right leg at the age of 34, because the diagnosis of epithelioid sarcoma was established histologically. No recurrence was observed for 9 years. Recently, the patient noticed multiple painful, ulcerative nodules about 1 cm in diameter on her scalp, trunk, and extremities. She refused extensive resection for a religious reason and died of massive hematemesis. Autopsy revealed metastatic epithelioid sarcoma in the skin, lungs, kidneys, pancreas, transverse colon, thyroid, and sternum. Chromosomal analysis of the tumor revealed various aberrations and an N-ras oncogene mutation.