Expression and clinical significance of cathepsin B and stefin A in laryngeal cancer.

The aim of this study was to investigate the roles of the cathepsin B cysteine protease and its endogenous inhibitor stefin A in laryngeal cancer. Immunohistochemistry was employed to detect the expression of cathepsin B and stefin A in 84 patients with laryngeal cancer, respectively. The protein expression of stefin A was negatively associated with lymphatic metastasis, recurrence of laryngeal cancer and the survival rate, which was not observed with cathepsin B protein expression. Both down-regulation of cathepsin B and up-regulation of stefin A in vitro significantly inhibited the migration, invasion and proliferation of laryngeal cancer cells, respectively. Our results strongly suggest that stefin A may be a potential predictor of laryngeal cancer and may be used in the molecular diagnosis and gene therapy of laryngeal cancer. Cathepsin B may be used as a promising therapeutic target in the treatment of laryngeal cancer.

Enhanced StefinA and Sprr2 expression during papilloma formation in HPV8 transgenic mice.

BACKGROUND: The human papillomavirus type 8 (HPV8) is associated with the development of non-melanoma skin cancer. Transgenic mice expressing the complete early gene region of HPV8 (E6/E7/E1/E2/E4=CER) or E6 separately under the control of the keratin14 promoter spontaneously developed papillomas characterized by varying degrees of epidermal dysplasia. Papilloma growth could be synchronized by a single UVA/B irradiation of the skin, which led to the development of papillomas within three weeks. OBJECTIVE: The objective of this study was to identify alterations in cellular gene expression correlated with HPV8 oncogene expression in transgenic mice. METHODS: We applied global gene expression profiling by microarray analysis and confirmed deregulation of cellular genes by qRT-PCR and immunohistochemical analysis. RESULTS: By comparison of non-lesional HPV8-CER skin with skin of the parental mouse strain FVB/n, two cellular genes, namely StefinA and Sprr2, coding for precursor proteins of the cornified envelope, were predicted to be strongly upregulated in transgenic skin, which could be confirmed in subsequent qRT-PCR experiments. StefinA and Sprr2 mRNA expression was enhanced until day 7 after UV treatment with higher levels in HPV8 positive skin. While the expression of both genes returned to a normal level in the course of epidermis regeneration in wt mice, the expression persisted elevated in hyperplastic transgenic skin. Staining of an UV induced papilloma of FVB/n wt mouse revealed also strong expression of StefinA and Sprr2 indicating that upregulation in later stages of papilloma formation is independent of HPV8. CONCLUSION: In non-lesional HPV8-CER transgenic skin StefinA and Sprr2 were found to be indirect/direct transcriptional targets of HPV8.

Modulation of cystatin A expression in human airway epithelium related to genotype, smoking, COPD, and lung cancer.

The cathepsin inhibitor Cystatin A (CSTA) has antiapoptotic properties linked with neoplastic changes in squamous cell epithelium, where it has been proposed as a diagnostic and prognostic marker of lung cancer. Notably, cystatin A is upregulated in dysplastic epithelium, prompting us to hypothesize that it might be modulated in chronic obstructive pulmonary disease (COPD), a small airway epithelial (SAE) disorder that is a risk factor for non-small cell lung cancer (NSCLC) in a subset of smokers. Here we report that genetic variation, smoking, and COPD can all elevate levels of CSTA expression in lung small airway epithelia, with still further upregulation in squamous cell carcinoma (SCC), an NSCLC subtype. We examined SAE gene expression in 178 individuals, including healthy nonsmokers (n = 60), healthy smokers (n = 82), and COPD smokers (n = 36), with corresponding large airway epithelium (LAE) data included in a subset of subjects (n = 52). Blood DNA was genotyped by SNP microarray. Twelve SNPs upstream of the CSTA gene were found to associate with its expression in SAE. Levels were higher in COPD smokers than in healthy smokers, who, in turn, had higher levels than nonsmokers. CSTA gene expression in LAE was also smoking-responsive. Using publicly available NSCLC expression data we also found that CSTA was upregulated in SCC versus LAE and downregulated in adenocarcinoma versus smoke-exposed SAE. All phenotypes were associated with different proportional expression of CSTA to cathepsins. Our findings establish that genetic variability, smoking, and COPD all influence CSTA expression, as does SCC, supporting the concept that CSTA may make pivotal contributions to NSCLC pathogenesis in both early and late stages of disease development.