Expression Of Stefin Research Articles

Myoepithelial cell-specific expression of stefin A as a suppressor of early breast cancer invasion.

Mammography screening has increased the detection of early pre-invasive breast cancers, termed ductal carcinoma in situ (DCIS), increasing the urgency of identifying molecular regulators of invasion as prognostic markers to predict local relapse. Using the MMTV-PyMT breast cancer model and pharmacological protease inhibitors, we reveal that cysteine cathepsins have important roles in early-stage tumorigenesis. To characterize the cell-specific roles of cathepsins in early invasion, we developed a DCIS-like model, incorporating an immortalized myoepithelial cell line (N1ME) that restrained tumor cell invasion in 3D culture. Using this model, we identified an important myoepithelial-specific function of the cysteine cathepsin inhibitor stefin A in suppressing invasion, whereby targeted stefin A loss in N1ME cells blocked myoepithelial-induced suppression of breast cancer cell invasion. Enhanced invasion observed in 3D cultures with N1ME stefin A-low cells was reliant on cathepsin B activation, as addition of the small molecule inhibitor CA-074 rescued the DCIS-like non-invasive phenotype. Importantly, we confirmed that stefin A was indeed abundant in myoepithelial cells in breast tissue. Use of a 138-patient cohort confirmed that myoepithelial stefin A (cystatin A) is abundant in normal breast ducts and low-grade DCIS but reduced in high-grade DCIS, supporting myoepithelial stefin A as a candidate marker of lower risk of invasive relapse. We have therefore identified myoepithelial cell stefin A as a suppressor of early tumor invasion and a candidate marker to distinguish patients who are at low risk of developing invasive breast cancer, and can therefore be spared further treatment. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Expression of stefin A is of prognostic significance in squamous cell carcinoma of the head and neck

Lysosomal proteases cathepsins B and L (CB, CL) and their endogenous inhibitors stefins A and B (SA, SB) are associated with tumor cell invasion and metastasis. The purpose of this study was to determine the immunohistochemical (IHC) localization of these parameters in tissue sections of 65 patients with operable head and neck squamous cell carcinoma (HNSCC) and to evaluate the prognostic significance of the observed IHC reactions. In SCC cells, a dot-like staining pattern for CB and CL was especially polarized in the perinuclear area and for stefins the characteristic IHC pattern was a diffuse cytoplasmic reaction. Higher SA immunoreactivity scores were found prognostically advantageous in univariate survival analysis [locoregional control (LRC), P = 0.003; disease-free survival (DFS), P = 0.023; disease-specific survival (DSS), P = 0.030] and appeared significant for predicting LRC (P = 0.019) in a multivariate setting. Among node-positive extracapsular extension-negative patients, SA positivity correlated with a favorable outcome (LRC, P = 0.094; DFS, P = 0.013; DSS, P = 0.012). In conclusion, SA immunoreactivity in tumor cells was related to a favorable prognosis. In the neck node-positive extracapsular extension-negative subgroup, SA immunoreactivity scores can be used to identify patients at increased risk for disease relapse.

Expression of cathepsin S and its inhibitor stefin A in sinonasal inverted papilloma

Dysregulation of cysteinyl cathepsins and their inhibitors, cystatins (stefins), were implied in progression of tumorgenesis; nevertheless, their role in sinonasal inverted papilloma (IP) is still unrecognized. The differential expression of cathepsins and stefins in IP and normal tissues were revealed by data of human Affymetrix U133A gene chips, real-time polymerase chain reaction (PCR) and immunohistochemistry. Among the cathepsins and stefins family, expression of cathepsin S and stefin A were most differentially expressed (down- and up-regulated, respectively) in IP tissue as compared with normal tissues. Their expression levels were validated by real-time PCR, which showed the expression level of cathepsin S was significantly down-regulated, whereas the expression of stefin A was significantly up-regulated in IP tissue compared to normal sinus mucosa. Using immunohistochemistry, expression of cathepsin S was observed in stromal and epithelial area macrophages of normal sinus mucosa, but no obvious expression of cathepsin S was found in IP tissue. In contrast, over-expression of stefin A was present in nearly all layers of the proliferative squamous cells of IP, but expression of stefin A was only detected in a scattered area of normal sinus mucosa. Down-regulation of cathepsin S and up-regulation of its endogenous inhibitor, stefin A, were found in IP tissues as compared with their expression level in normal sinus mucosa tissues. The biological significance of inverse expression of both stefin A and cathepsin S in sinonasal IP need further investigation in the future.

Expression of cathepsin S and its inhibitor stefin A in sinonasal inverted papilloma

Background: Dysregulation of cysteinyl cathepsins and their inhibitors, cystatins (stefins), were implied in progression of tumorgenesis; nevertheless, their role in sinonasal inverted papilloma (IP) is still unrecognized. Methods: The differential expression of cathepsins and stefins in IP and normal tissues were revealed by data of human Affymetrix U133A gene chips, real-time polymerase chain reaction (PCR) and immunohistochemistry. Results: Among the cathepsins and stefins family, expression of cathepsin S and stefin A were most differentially expressed (down- and up-regulated, respectively) in IP tissue as compared with normal tissues. Their expression levels were validated by real-time PCR, which showed the expression level of cathepsin S was significantly down-regulated, whereas the expression of stefin A was significantly up-regulated in IP tissue compared to normal sinus mucosa. Using immunohistochemistry, expression of cathepsin S was observed in stromal and epithelial area macrophages of normal sinus mucosa, but no obvious expression of cathepsin S was found in IP tissue. In contrast, over-expression of stefin A was present in nearly all layers of the proliferative squamous cells of IP, but expression of stefin A was only detected in a scattered area of normal sinus mucosa. Conclusion: Down-regulation of cathepsin S and up-regulation of its endogenous inhibitor, stefin A, were found in IP tissues as compared with their expression level in normal sinus mucosa tissues. The biological significance of inverse expression of both stefin A and cathepsin S in sinonasal IP need further investigation in the future.

The Expression of Lysosomal Proteinases and Their Inhibitors in Breast Cancer: Possible Relationship to Prognosis of the Disease.

Proteolytic enzymes have been proposed as new biological prognostic indicators to facilitate decisions about treatment of breast cancer patients following surgery. We reported earlier that the activities of cysteine proteinases (CP), cathepsin (Cat) B and cathepsin (Cat) L and the expression of stefin A might be associated with breast tumor progression and prognosis. Here, the protein concentrations of Cats D, B and L and stefin A have been measured in a series of 60 matched pairs of breast tumours and control adjacent tissues, using ELISAs developed in our laboratory. Median tumor concentrations of Cat D (47 pm/mg), Cat B (222 ng/mg) and Cat L (88 ng/mg) were significantly (p<0.0005) increased by 7 fold, 27 fold and 6 fold, respectively. Much greater increases in the activities of Cat B (63 fold) and of Cat L (274 fold) were found, indicating activation of proCat B and proCat L and/or to a decrease in specific endogenous cystatins. However, the 1.6-fold decreased (p<0.0001) levels of inhibition by cystatins could not be entirely responsible for more than 100-fold increased ratio of CP:cystatins activity. Moreover, stefin A was either increased or decreased in tumor samples, resulting in a 1.4-fold median increase in tumors. Comparing the biological parameters with the established histo-pathological prognosticators, we found that the increased protein concentration of Cat B was associated with lymph node involvement (p<0.009) and higher stage (p<0.003), and both Cat B and Cat L activities were more increased in high grade tumours (p<0.05). Survival analysis revealed that stefin A was the most significant prognostic factor for disease-free (p<0.008) and overall survival (p<0.02), followed by increased Cat B activity and protein concentration. Cat L was of borderline significance while Cat D was not significant for prognosis. We conclude that enhanced activation of CP, due partially to an imbalance between cysteine proteinases and inhibitors is linked to the progression of breast cancer. Larger sample size is needed to confirm the prognostic significance of stefin A, Cat B and Cat L.