title: Cathepsin B and D expression in squamous cell carcinoma.
abstract: To elucidate involvement of proteinases in malignancy of keratinocytes, expression of cathepsin B, a cysteine proteinase, and cathepsin D, an aspartic proteinase, was ascertained in formalin-fixed paraffin-embedded specimens of normal skin, squamous cell carcinoma (SCC). Bowen's disease, seborrhoeic keratosis and basal cell carcinoma (BCC). Presence of procathepsin B and an intermediate form of cathepsin D was confirmed by Western blotting and enzyme activity analysis. Cathepsin B stained more intensely in SCC tumour cells than in normal epidermis; staining patterns were diffuse, granular or both. Diffuse and granular patterns (procathepsin B and mature enzyme, respectively) appeared in inner and outer parts of tumour islands, respectively. Five of 20 cases of Bowen's disease showed diffuse enhanced cathepsin B expression; 20 cases of seborrhoeic keratosis or BCC did not. Cathepsin D stained intensely in tumour cells of half the SCC cases. The staining manner and distribution of cathepsins B and D was similar in the cytoplasm of cancer cells. No enhanced staining of cathepsin D was seen in any cases of Bowen's disease, seborrhoeic keratosis, or BCC. Coexistence and localization of active mature forms of cathepsins B and D suggests that cooperation between the two enzymes may play an important part in invasion of SCC.
authors.affiliation: Department of Dermatology, National Defense Medical College, Saitama, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kawada
authors.forename: K
authors.initials: K
authors.lastname: Hara
authors.forename: E
authors.initials: E
authors.lastname: Kominami
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Hiruma
authors.forename: A
authors.initials: A
authors.lastname: Ishibashi
mesh_terms: D015153:Blotting, Western; D001913:Bowen's Disease / Q000201:enzymology; D002280:Basal Cell Carcinoma / Q000201:enzymology; D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D002401:Cathepsin B / Q000378:metabolism; D002402:Cathepsin D / Q000378:metabolism; D002403:Cathepsins / Q000378:metabolism*; D004817:Epidermis / Q000201:enzymology; D006801:Humans; D017492:Keratosis, Seborrheic / Q000201:enzymology; D009361:Neoplasm Invasiveness; D012878:Skin Neoplasms / Q000201:enzymology*
chemical_list: D002403:Cathepsins; D002401:Cathepsin B; D002402:Cathepsin D