A New Analytical Method for Determination of Cathepsin L Based on the Surface Plasmon Resonance Imaging Biosensor

The purpose of this study was to develop a new method for a determination of the cathepsin L—biosensor based on the Surface Plasmon Resonance Imaging technique. The cathepsin L is an endopeptidase, which degrades proteins and plays an important role in various processes occurring in the human body. The detection technique, Surface Plasmon Resonance Imaging, is an optical, label-free technique, which can be used for quantitative determination of the different proteins. In order to bind the enzyme, the cathepsin L inhibitor—RKLLW-NH2 was used. The validation process showed that parameters: precision, accuracy, and selectivity of the method were acceptable. The analytically useful range of the standard curve was 0.50 ng/mL—15.00 ng/mL. The detection and quantification limit of method was 1.67 pg/mL and 5.07 pg/mL, respectively. The usefulness of the developed method was confirmed by the determination of the cathepsin L concentration in the blood plasma of some healthy persons and in the blood plasma of patients. The obtained results were compared with the results obtained by the ELISA. It was found that the correlation between these two methods was very strong, what suggest that the developed method can be used as the competitive method to the ELISA

Utility of cystatin C as a potential bladder tumour biomarker confirmed by surface plasmon resonance technique

Background & objectives: The determination of cystatin C (cysC) may be helpful in diagnosis and monitoring of cancer because the pathogenesis of cancer is linked with an increased activity of cysteine peptidases (cathepsins) and a decrease of cysC concentration. This study was aimed to examine the utility of cysC as a marker of bladder cancer (BCa) to be used in the diagnosis. Methods: This study was conducted with 90 patients with BCa and 27 healthy people. Patients with other cancers, inflammation process and impaired renal function were excluded from the study. The concentrations of cysC in the plasma and urine were measured by surface plasmon resonance imaging technique. Results: The concentration of cysC in the serum taken from the patients with BCa [0.35±0.02 μg/ml (range: 0.20-0.78 μg/ml)] was significantly (P<0.001) lower than the serum cysC concentration of the healthy people [0.68±0.05 μg/ml (range: 0.52-0.89 μg/ml)]. The urinary cysC concentration of the BCa patients [0.19±0.01 μg/ml (range: 0.09-0.34 μg/ml)] was not significantly different from the urinary cysC concentration of the healthy people [0.24±0.02 μg/ml (range: 0.16-0.33 μg/ml)]. Receiver operating characteristic (ROC) curve showed that BCa patients with cysC concentration <0.54 μg/ml [sensitivity: 87%; specificity: 92%; area under the curve (AUC) of ROC: 0.927; P=0.02] could be optimally separated from healthy people. The ROC curve further showed that superficial low-grade patients with cysC concentration lower than 0.36 μg/ml (sensitivity: 0.63%; specificity: 0.58%; AUC of ROC: 0.635; P=0.08) could not be optimally separated from high-risk tumour patients. Interpretation & conclusions: BCa patients have lower serum cysC concentration than the control group. Serum cysC may be considered as a potential marker of BCa but not its aggressiveness

A New Analytical Method for Determination of Cathepsin L Based on the Surface Plasmon Resonance Imaging Biosensor

The purpose of this study was to develop a new method for a determination of the cathepsin L&#8212;biosensor based on the Surface Plasmon Resonance Imaging technique. The cathepsin L is an endopeptidase, which degrades proteins and plays an important role in various processes occurring in the human body. The detection technique, Surface Plasmon Resonance Imaging, is an optical, label-free technique, which can be used for quantitative determination of the different proteins. In order to bind the enzyme, the cathepsin L inhibitor&#8212;RKLLW-NH2 was used. The validation process showed that parameters: precision, accuracy, and selectivity of the method were acceptable. The analytically useful range of the standard curve was 0.50 ng/mL&#8212;15.00 ng/mL. The detection and quantification limit of method was 1.67 pg/mL and 5.07 pg/mL, respectively. The usefulness of the developed method was confirmed by the determination of the cathepsin L concentration in the blood plasma of some healthy persons and in the blood plasma of patients. The obtained results were compared with the results obtained by the ELISA. It was found that the correlation between these two methods was very strong, what suggest that the developed method can be used as the competitive method to the ELISA

Concentration of UHCL1 in the Serum of Children with Acute Appendicitis, Before and After Surgery, and Its Correlation with CRP and Prealbumin

Ubiquitin-mediated protein degradation plays a crucial role in various cellular processes, including signal transduction, cell differentiation, and stress response. Ubiquitin C-terminal hydrolase 1 (UCHL1) is a unique deubiquitinating enzyme that has both hydrolase and ligase activities. The aim of this study was the determination of UCHL1 concentration in serum of children with appendicitis, before and after the surgery. Material and methods: 42 children with acute appendicitis, who were managed at the Pediatric Surgery Department, between 2013 and 2014, were randomly included into the study (age 9 months up to 14 years, mean age 2.5 + 1 years). There were 15 girls and 27 boys. 18 healthy, age-matched subjects, admitted for planned surgeries served as controls. Exclusion criteria were: severe preexisting infections, immunological or cardiovascular diseases that required long-term medication, and complicated cases of appendicitis with perforation of appendix and/or peritonitis. Results: The UCHL1 concentrations in the blood plasma of patients with acute appendicitis, were highest before the surgery, and were above the range of concentrations measured in controls, the difference was statistically significant. The UCHL1 concentration measured 24 and 72 h after the operation, slowly decreased over time, and still did not reach the normal range, when compared with the concentration measured in controls (p < 0.05). Conclusions: UCHL1 concentration may reflect the metabolic response to acute state inflammation, and the process of gradual ebbing of the inflammation. The method of operation—classic open appendectomy, or laparoscopic appendectomy, does not influence the general trend in UCHL1 concentration in children with appendicitis. There is strong negative correlation between prealbumin and UCHL1 concentrations

Higher Content but No Specific Activity in Gelatinase B (MMP-9) Compared with Gelatinase A (MMP-2) in Human Renal Carcinoma

Gelatinases belong to a group of enzymes known as matrix metalloproteinases (MMPs). Gelatinases A and B (MMP-2 and MMP-9, respectively) are the enzymes with the highest ability to destroy collagen, primarily type IV collagen, which is an essential component of the base membrane. Hence, it can be assumed that they are involved, among other things, with the metastasis process of cancer. As a result, the objective of this study was to assess the presence, activity, and expression of selected gelatinases in human renal cancer. Healthy (n = 20) and clear-cell kidney cancer tissue samples (G2 n = 10, G3 n = 10) were analyzed. The presence and content of MMPs were measured using the Western blot and ELISA methods, respectively. The activity (actual and specific) was analyzed with a fluorimetric method. The presence of both investigated enzymes was demonstrated in the representative zymogram. MMP-9 showed the most intensive saturation. It has been observed that both gelatinases occur primarily in high molecular complexes in the human kidney, regardless of whether it is a control or tumor tissue. Both gelatinases were present in comparable amounts in healthy tissues of the kidney. MMP-9 showed a higher content than MMP-2 in both renal cancer grades, but we observed the enhanced activity of both gelatinases with an increase in the grade of renal cancer. A higher MMP-9 content and, on the other hand, lower specific activity in the cancer tissue suggest that MMP-9 is predominantly present in an inactive form in renal cancer. The higher activity of MMP-9 demonstrated using the zymography method may be a cause of different values of activity that depend on the phase of the carcinogenic process. The present study revealed changes in the tested gelatinases in healthy and cancerous tissues of renal cell carcinoma. Therefore, it can be concluded that matrix metalloproteinases 2 and 9 are enzymes directly involved in carcinogenesis, and hence, it seems that MMPs may have potential in the diagnosis and treatment of renal carcinoma