title: Immunohistochemical localization of cathepsin L and cystatin A in normal skin and skin tumors.
abstract: Cathepsin L, a cysteine proteinase, and cystatin A, an inhibitor of cysteine proteinases, are thought to regulate the invasion and metastasis of malignant cells. In this study, the expression of cathepsin L and cystatin A in skin tumors was investigated immunohistochemically in order to examine the relationship between these two enzymes in the pathophysiology of malignant cells. Formalin-fixed and paraffin embedded specimens from normal skin, seborrheic keratoses, and squamous cell carcinomas were reacted with polyclonal antibodies against rat cathepsin L or cystatin a which cross-react to human cathepsin L and cystatin A, respectively. The consequent immunostaining of these enzymes was observed to be strong in normal skin (4 cases) and seborrheic keratosis (6 cases). In well-differentiated squamous cell carcinoma (SCC) (9 cases), staining for cathepsin L and cystatin A was moderately positive in differentiated tumor cells and negative in undifferentiated SCC (5 cases). The degree of staining of these enzymes was inversely correlated with the differentiation of the malignant cells. These results suggest that the immunohistochemical analysis of cathepsin L and cystatin A is a useful indicator for an aspect of malignancy in human epidermal keratinocytes.
authors.affiliation: Srinakharinwirot University Skin Center, Bangkok, Thailand.
authors.forename: Piti
authors.initials: P
authors.lastname: Palungwachira
authors.forename: Mie
authors.initials: M
authors.lastname: Kakuta
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yaguchi
authors.forename: Ryoji
authors.initials: R
authors.lastname: Tsuboi
authors.forename: Kenji
authors.initials: K
authors.lastname: Takamori
authors.forename: Hideoki
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D056668:Cathepsin L; D002403:Cathepsins / Q000032:analysis*; D046508:Culture Techniques; D015891:Cystatins / Q000032:analysis*; D003546:Cysteine Endopeptidases; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017492:Keratosis, Seborrheic / Q000473:pathology*; D008297:Male; D012016:Reference Values; D012680:Sensitivity and Specificity; D012871:Skin Diseases / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D015891:Cystatins; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L; C534280:Ctsl protein, rat