Takehiko Aoki

A histochemical and immunohistochemical study of extra-ocular sebaceous carcinoma

A histochemical and immunohistochemical study of five cases of extra‐ocular sebaceous carcinoma was performed using formalin‐fixed and paraffin‐embedded tissue specimens. Histochemically, the clear cells of sebaceous carcinomas were negative with periodic acid‐Schiff and alcian blue staining. Immunohistochemically, the tumour cells of sebaceous carcinomas showed positive reactions for epithelial membrane antigen, human milk fat globules subclass 1, human milk fat globules subclass 2 and Leu M1, but did not express carcinoembryonic antigen, breast carcinoma associated antigen, S‐100 protein, gross cystic disease fluid protein‐15 or Dako M1. These histochemical and immunohistochemical findings were compared with those of other skin cancers which must be distinguished histopathologically from sebaceous carcinoma. We conclude that sebaceous carcinoma can be distinguished from eccrine porocarcinoma, malignant clear cell hidradenoma, extramammary Pagets disease, malignant trichilemmoma, squamous cell carcinoma and basal cell carcinoma by histochemical and immunohistochemical techniques using formalin‐fixed and paraffin‐embedded tissue specimens.

An immunohistochemical study of E-cadherin expression in human squamous cell carcinoma of the skin: relationship between decreased expression of E-cadherin in the primary lesion and regional lymph node metastasis.

E‐cadherin is a Ca2+‐dependent, intercellular adhesion molecule that is specifically expressed in epithelial tissues and is essential for maintaining intercellular connections. It has been reported that E‐cadherin expression of tumor cells is often decreased in some types of metastasizing carcinomas as compared with those without metastasis.

Chilblain lupus erythematosus of Hutchinson responding to surgical treatment: a report of two patients with anti-Ro/SS-A antibodies

We report two patients with chilblain lupus erythematosus of Hutchinson (CL) who responded to surgical treatment. One of them was a 72‐year‐old woman (case 1), and the other a 62‐year‐old man (case 2). We attempted to treat these patients by excising the lesions and subsequently performing full‐thickness free skin grafting, using skin from the abdominal region. No recurrence was seen in the operated area 7 years (case 1) and 3 years (case 2) after surgery. However, lesions persisted in the areas not operated upon, and in the areas where lesions had not been adequately excised. These results suggest that surgical removal of local factors reduces the rash in these cases. In addition, both patients were serologically positive for the anti‐Ro/SS‐A antibody suggesting that local expression of the Ro/SS‐A antigen may be involved in the pathogenesis of the skin lesions. To our knowledge, full thickness free skin grafting has not been used previously to treat CL‐associated skin lesions, and is promising as a treatment for patients who do not respond to conventional means.

Identification of K1/K10 and K5/K14 keratin pairs in human melanoma cell lines

Keratin expression in cultured malignant melanoma cells has been studied only rarely. Moreover, no studies have reported of universality of keratin expression in human malignant melanoma cells. In this study, therefore, we analyzed keratin expression in eight cell lines. Using a low-salt aqueous solution without high salt and Triton X-100, as a washing buffer for keratin extraction, followed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and immunological analysis, we demonstrated keratin expression in all eight human malignant melanoma cell lines. The keratin polypeptide expressions common to all melanoma cells were K1, K5, K10 and K14. In addition, K8, K13, K17 and K18, respectively, were detected in individual cells. A measure of keratin expression universality in malignant melanoma cells may have implications regarding their invasive and metastatic behaviors, co-expressed with vimentin.

A case of malignant haemangioendothelioma treated with recombinant interleukin‐2

A case of malignant haemangioendothelioma of the scalp in an 82‐year‐old female treated with intralesional, intra‐arterial and intravenous recombinant interleukin‐2 (rIL‐2) is reported. The scalp lesions disappeared after injection of 35 350 000 Japan reference units of rIL‐2 and excision of the residual tumour. Immunohistochemical characterization of the cells infiltrating the lesion after rIL‐2 administration revealed 30–40% CD4+ and CD8+ T lymphocytes, 20–30% macrophages and 5–10% natural killer cells. These findings are similar to those in other human cancers. Almost all of the cells in the intersticies of the lesion after rIL‐2 injection expressed leucocyte function‐associated antigen‐1, and some of the tumour cells and the infiltrating cells around them expressed intercellular adhesion molecule‐1. HLA‐DR‐positive cells markedly increased in number after rIL‐2 administration. This report suggests that rIL‐2 administration is the most effective therapy for malignant haemangioendothelioma.

E-cadherin Expression in Skin Tumors Using an AMeX Immunohistostaining Method

The AMeX (acetone‐methylbenzoate‐xylene) method results in good preservation of tissue and morphological details, almost equivalent to that of routinely processed formalin‐fixed and paraffin‐embedded tissue specimens, and of antigenicity equivalent to that of fresh frozen tissue specimens. It has been reported that the expression of the cell‐cell adhesion molecule E‐cadherin is often decreased in some types of carcinomas. A decrease in E‐cadherin expression is associated with the invasive or metastatic potential of tumor cells. We immunohistochemically examined the expression of E‐cadherin with anti‐E‐cadherin monoclonal antibody in various skin tumors (25 basal cell carcinomas, 11 squamous cell carcinomas, 9 keratoacanthomas, and 11 Bowens disease) using the AMeX method and found that this method preserved antigenicity well without pretreatment. E‐cadherin expression was decreased in 18.2% of squamous cell carcinomas and 33.3% of keratoacanthomas. On the other hand, it was preserved in almost all Bowens disease and basal cell carcinomas. From the results of our study, we suggest that Bowens disease and basal cell carcinoma do not have much metastatic potential due to retention of high levels of E‐cadherin expression. We hope to apply the AMeX method to other immunohistochemical examinations because this is a very useful staining method.

Detecting expression of keratins 8/18 in human HaCaT keratinocytes.

Differences in treatment solution affect the efficiency of keratin extraction in cultured human squamous cell carcinomas, malignant melanomas, and melanocytes. Using an aqueous solution that is excellent for cultured cells, we focused this study on the expression of keratin subunits in the spontaneously immortalized human keratinocyte cell line HaCaT. We extracted several keratin (K) subunits, namely K4, K7, K8, K15, K17, and K18, and ATP synthase alpha-chain, in addition to those previously reported by Boukamp et al. (J Cell Biol 1988;106:761-771) in human HaCaT keratinocytes. In particular, K8 and K18 subunits, which are related to tumorigenesis, may be very important subunits within the specificities of immortalized HaCaT cells. Vimentin, which is frequently co-expressed in cultured epithelial cell lines, was not expressed.