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REGULATORY PIECHANISIJS OF EXPRESSION OF A HUMAN GENE ESTABLISHMENT AND CHARACTERIZATION OF A NOVEL ENCODING FOR THE MELANOMA-ASSOCIATED ME491 ANTIGEN. GASTRIC CANCER CELL LINE FROM DERMATOMYOSITIS

PATIENT. HAK HOTTA. Department of Microbiology, Kobe University School of Medicine, Kobe, Hyogo.

ATSUKO SEKINE. HIKARU ETO. YUKINORI OHTA. AND SHIGEO NISHIYAMA. Department of Dermatology, Kitasato University School of Medicine, Sagamihara.

A human gene encoding for a melanoma-associated We have established a novel gastric cancer cell ME491 antigen was molecularly cloned from a human line, MKYT. from surgically removed gastric cancer genomic library, and regulatory mechanisms of the tissue of 58 y/o dermatomyositis patient. The cells gene expression was analyzed. The promoter, identi- are growing in RPM1 1640 medium supplemented with fied by nucleotide sequencing and primer extension 10% FBS in stable condition for more than 1 year. analyses, was found to utilize the GC box but not The doubling time of MKYT cells is about 34 hours. the TATA box. CAT assay revealed that the promoter Chromosome analysis of these cells revealed modal exerted its activity in Ha-ras-transformed cells number of 43 with some marker chromosomes. The more efficiently than in non-transformed cells. It tumor cells grew rapidly in nude mice, however, was also found that a cryptic promoter sequence in none of the mice developed myositis. Surprisingly, an intron, which could initiate ME491 antigen when culture supernatant from MKYT cells was added expression, was partially repressed by an upstream to rat muscle cell (L6) culture, the growth of L6 repressor sequence. These positive and negative was markedly increased, suggesting that this cell regulatory sequences may be responsible for the line produces muscle cell growth factor in vitro. stage-dependent expression of ME491 antigen. Control gastric cancer cell line did not show such

activity. MKYT cell line would be useful tool to study pathogenesis of dermatomyositis.

CYTOFLUOROMETRICAL ANALYSIS OF DNA HISTOGRAM OF PAGET CELLS IN EXTRAMAMMA RY PAGET'S DISEASE.

OSAMU MORI, HIROSHI HACHISUKA, AND YOICHIRO SASAI. Department of Dermatology, Kurume Univ. School of Medicine, Kurume. Separation of Paget cells was performed from five cases

of extramammary Paget's disease. Stripped skin was treated with EDTA and trypsin, and epidermal cell suspension was obtained. No dermal invasion and metastasis of regional lymph nodes was seen in four cases. In a case, in which a thumb sized red nodule was seen, dermal invasion and metastasis of regional lymph nodes were present. DNA histogram of Paget's cells revealed biphasic pattern in the four cases, whereas the latter case where the nodule

WHY CAN EPIDERMAL CYSTS BE EASILY PULLED OUT?

YOSHIHIKD MITSUHASHI, NAOMI AKITA AND YUKO TAKAGI Department of Dermatology, Hirosaki University School of Medicine, Hirosaki Non-infected epidermal cysts can easily be pulled out. The above clinical observation can be supported by the histopa- thological finding that the wall of epidermal cysts are fre- quently separated from the dermal matrix. Why are they easi- ly separated from the dermis? Two explanations are possible. First, their adherence system of the dermal-epidermal junc- tion area is impaired. Second, sorrounding dermal matrix is altered. We examined epidermal cysts by inniunopathological techniques focusing on the dermal-epidermal junction area of the cvsts, and compared it with that of the eaidermis. We studied BP antigen; laminin, type IV and type Vii collagen. We have also done an electron microscopical observation. The results showed that all the observed components of the epi- dermal cysts are the same as those of the epidermis. We con- eluded that the easiness of separation may be contributed to alternations surrounding dermal matrix.

was present showed aneuploid pattern. The aneuploid pattern was seen in Paget cells from erythematous lesion as well as in Paget cells from the nodule. The aneuploid found in DNA histogram indicates the biological behavior of PaSet cells.

ULTRASTRUCTURE OF THE LESIONS OF EXPERIMENTAL SKIN CANCER AFTER TOPICAL APPLICATION OF GLUTARALDEHYDE SOLUTION

KEIICHI UEDA, KAZUMORI ISHIGURO AND KEN-ICHI KAWAHARA Department of Dermatology, Fukui Medical School, Fukui, Japan

Ultrastructural investigation was performed on the lesions of experimental skin cancer in C3H mice. 0.5 ml of 2% glutaraldehyde solution was injected to the lesions. Twenty four hours after injection, the lesions were biopsied, and ultrastructural investigation was performed. Nuclei of the tumor cells were pyknotic and nucleoplasm was uneven in figure. In the cytoplasm, vacuoles were increased in number, and mitochondria were swollen. Some of them showed sponge- like configuration. Capillaries were filled with erythro- cytes and vacuoles were increased in the cytoplasm of endo- thelial cells.

These findings showed that glutaraldehyde solution was effective against the lesions of experimental skin cancer.

IMMUNOHIS- CAL CHARACTERIZATION OF EPIDERMAL PROTEINS IN CALCIPYINGEPITHBLIOMA

SHINICHI WATANABE, KBIKO WAGATSUMA, EIKO ICHIKAWA, MASAKO MIZGGUCHI, AND HISASIB TAKAHASHI. Department of Dermatology, Teikyo University School of Medicine, Tokyo, Japan.

The present study was conducted to examine the immunohistochemical distribution of various epidermat proteins in calcifying epithelioma (CA) in order to confbm the histogenesis of this tumor. Specimens were obtained from 15 cases of CA. Various kinds of anti-cytokeratin antibodies, anti-human filaggrin antibody, and rabbit amiserum against involucrin were used as primary antibodies. Stainings were performed using the avidin-biotin immunoperoxidase medmd. In CA, only transitional celts were strongly stained with involuctin, while basophilic cells and shadow cells showed no reactivity with involucrin or the other cpidermal protein antibodies. Epidermoid cells were stained with some anti-keratin antibodies. In normal hair, the inner root sheath reveated positive stainings with only No.13 cytokeratin and involucrin antibodies. The hair medulla and the lower part of the hair cortex expressed only involucrin. These findings suggest that the tmnor arises from hair germ cells which are differentiating toward hair cortex. The transitional cells are assumed to cormspond to the lower hair cortex and the shadow cells to keratinous xone of the hair.