Three-dimensional hair follicular differentiation of a trichilemmoma cell line in vitro

1 alpha,25-dihydroxy vitamin D3 modulation of HLA-DR mRNA induced by gamma-interferon in cultured epithelial tumor cell lines

Using three cultured epithelial tumor cell lines, we investigated and analyzed the effects of gamma-interferon (gamma-IFN) and 1 alpha,25-dihydroxy vitamin D3 (1,25-(OH)2D3) on the levels of HLA-DR (alpha) mRNA and HLA-DR (beta) mRNA by Northern blot analysis. After treatment with gamma-IFN alone, the levels of the mRNA increased. Treatment with both gamma-IFN and 1,25-(OH)2D3 at the same time resulted in a significant decrease in the levels of mRNA in K-TL-1, IK-TL-2, and M-TL cells as compared to those induced by gamma-IFN alone.

Novel lysosomal glycoaminoacid storage disease with angiokeratoma corporis diffusum

A 46-year-old Japanese woman had disseminated angiokeratoma, confirmed by electron microscopy which showed numerous cytoplasmic vacuoles in cells of the kidney and skin. Enzyme activities against synthetic and natural substrates in leucocytes and fibroblasts were normal. Her urine contained a large amount of sialylglycoaminoacids, with predominant excretion of an O-glycoside-linked glycoaminoacid.

Adenylate cyclase system of human trichilemmoma cell line

The adenylate cyclase system of an established human trichilemmoma cell line was investigated. Stimulators of human epidermal adenylate cyclase system, epinephrine, histamine, adenosine, and prostaglandin E increased cyclic AMP levels of the trichilemmoma cells. The effects of epinephrine, histamine, and adenosine were inhibited by the addition of propranolol (a beta-adrenergic antagonist), cimetidine (histamine H2-antagonist), and theophylline (adenosine-receptor antagonist), respectively. The epinephrine, histamine, and prostaglandin E effects were augmented by the addition of cyclic AMP (cAMP) phosphodiesterase inhibitor, isobutylmethylxanthine (IBMX); the adenosine effect was augmented by another phosphodiesterase inhibitor, papaverine. Without the addition of these phosphodiesterase inhibitors, the maximal accumulations were observed at 3 min incubation. Following this, the cAMP content returned to the basal level, and the cells did not respond to repeated stimulations with the same initial stimulator. This fact indicates receptor-specific refractoriness. For example, epinephrine-pretreated cells did not respond to epinephrine, but retained their sensitivity to histamine. It has been known that normal epidermal keratinocytes are regulated in vitro by glucocorticoids, colchicine, and retinoids, resulting in the augmentation of their beta-adrenergic response. Only hydrocortisone treatment on the trichilemmoma cells resulted in the augmentation of the beta-adrenergic response. Although the established human trichilemmoma cell line has similar adenylate cyclase systems as normal epidermis, it apparently has lost some of the regulatory mechanism of the beta-adrenergic response.

Recombinant gamma interferon induces HLA-DR expression on squamous cell carcinoma, trichilemmoma, adenocarcinoma cell lines, and cultured human keratinocytes

We investigated the effects of recombinant human gamma interferon on the induction of HLA-DR expression by two human squamous cell carcinoma, three trichilemmoma, one eccrine carcinoma, two adenocarcinoma cell lines, and cultured human keratinocytes in vitro. None of eight epithelial cell lines or keratinocytes expressed HLA-DR without gamma interferon treatment. In contrast, pure gamma interferon (500 IU/ml, 72-h treatment) induced HLA-DR expression on 1/2 squamous cell carcinoma, 3/3 trichilemmoma, 2/2 adenocarcinoma cell lines, and 4/4 keratinocyte cell lines, as determined using a fluorescence-activated cell sorter. A maxillary squamous cell carcinoma line and an eccrine carcinoma cell line failed to express HLA-DR with gamma interferon treatment; however, the growth of cells was inhibited by gamma interferon treatment. By indirect immunoperoxidase techniques, tumor cells such as Bowen's disease and squamous cell carcinoma were found to express HLA-DR. Since HLA-DR expression has been shown to be important for various immune responses, these findings suggest that gamma interferon plays important roles in various immune-related skin diseases.

Monoclonal antikeratin antibody: production, characterization, and immunohistochemical application

A monoclonal antikeratin antibody, EKH4, was produced from a hybridoma cell line which was established by fusing P3X63SAg8 mouse myeloma cells with spleen cells of mice immunized with human trichilemmoma cells. Immunoblot analysis showed that EKH4 antibody reacts predominantly with 50 kilodalton keratin polypeptide in normal epidermis. By indirect immunofluorescence and immunoperoxidase techniques, EKH4 antibody reacted with the lower 2-3 cell layers of the epidermis as well as most cells of pilosebaceous follicle of human and animal skin. Tumor cells of human basal cell epitheliomas and squamous cell carcinomas were also stained with this antibody. The staining was much more regular and intense compared with an available monoclonal antikeratin antibody, AE1. In the lesion of epidermal proliferative disorders, such as psoriasis and actinic keratosis, the entire epidermis instead of the lower layers was stained with EKH4 antibody. Normal skin overlying or adjacent to epithelial tumors also showed positive staining in the entire epidermis. By using indirect immunoperoxidase technique, EKH4 also stained alcohol-fixed, paraffin-embedded tissue sections.