Fsn0503h antibody-mediated blockade of cathepsin S as a potential therapeutic strategy for the treatment of solid tumors

Evaluation of serum levels of cathepsin S among colorectal cancer patients

Objective

Colorectal cancer is the third most common cancer worldwide. Cathepsins are protease that are known to be involved in cancer progression and metastasis. The aim of this study is to evaluate the levels of serum cathepsin S in patients and control subjects and its effects on the prognosis of the cancer.

Methods

In this case-control study, colorectal cancer patients referred to our gastroenterology clinic were included. The control group consisted of healthy individuals. Cathepsin S levels were analyzed in these patients and the check list consisting of demographic data, cancer stage, colonoscopy findings, CEA marker and cathepsin S levels were recorded.

Results

Of 80 patients and healthy controls included in the study, age, gender and BMI were not significantly different among the two groups, p = 0.265, p = 0.752 and p = 0.2, respectively. Cathepsin S levels were significantly greater in-patient group p < 0.001 and was significantly correlated with the stage of the tumor. CEA marker was also linear related with the increased levels of cathepsin S, p < 0.001.

Conclusion

Our study concluded that cathepsin S is elevated in the cancer patients and can be a significant marker for the prognosis of colorectal cancer.

Targeting lysosomes in human disease: from basic research to clinical applications

In recent years, accumulating evidence has elucidated the role of lysosomes in dynamically regulating cellular and organismal homeostasis. Lysosomal changes and dysfunction have been correlated with the development of numerous diseases. In this review, we interpreted the key biological functions of lysosomes in four areas: cellular metabolism, cell proliferation and differentiation, immunity, and cell death. More importantly, we actively sought to determine the characteristic changes and dysfunction of lysosomes in cells affected by these diseases, the causes of these changes and dysfunction, and their significance to the development and treatment of human disease. Furthermore, we outlined currently available targeting strategies: (1) targeting lysosomal acidification; (2) targeting lysosomal cathepsins; (3) targeting lysosomal membrane permeability and integrity; (4) targeting lysosomal calcium signaling; (5) targeting mTOR signaling; and (6) emerging potential targeting strategies. Moreover, we systematically summarized the corresponding drugs and their application in clinical trials. By integrating basic research with clinical findings, we discussed the current opportunities and challenges of targeting lysosomes in human disease.

Cathepsin S as a target in gastric cancer

Cathepsin S (Cat S) is a protein expressed in some epithelial cells, which appears to be associated with cancer metastasis and recurrence. The abnormal expression of Cat S has been reported to be associated with the progression of certain types of gastrointestinal neoplasms, including gastric cancer (GC). There is a need to identify novel biomarkers and therapeutic targets associated with the growth, invasion and migration of GC cells, in order to develop non-invasive diagnostic and prognostic procedures and design new therapeutic approaches. The aim of the present study was to assess the association between Cat S and oncogenic processes implicated in the development of GC, focusing on the diagnostic and therapeutic potential of this molecule in GC. A search was conducted through the PubMed and Cochrane Central Register of Controlled Trials electronic databases for relevant literature published between 2003 and 2018, using the mesh terms 'cathepsin S' and 'cancer' and 'gastric cancer'.

Cathepsin B Is Upregulated and Mediates ECM Degradation in Colon Adenocarcinoma HT29 Cells Overexpressing Snail

During tumor development and ongoing metastasis the acquisition of mesenchymal cell traits by epithelial carcinoma cells is achieved through a programmed phenotypic shift called the epithelial-to-mesenchymal transition, EMT. EMT contributes to increased cancer cell motility and invasiveness mainly through invadosomes, the adhesion structures that accompany the mesenchymal migration. The invadosomes and their associated proteases restrict protease activity to areas of the cell in direct contact with the ECM, thus precisely controlling cell invasion. Our data prove that Snail-overexpressing HT-29 cells that imitate the phenotype of colon cancer cells in the early stage of the EMT showed an increase in the expression and pericellular activity of cathepsin B. It appears that the pericellular localization of cathepsin B, also observed in colon and rectum adenocarcinoma tissue samples, plays a key role in its function.

Cathepsins: Potent regulators in carcinogenesis

Cathepsins (CTS) are mainly lysosomal acid hydrolases extensively involved in the prognosis of different diseases, and having a distinct role in tumor progression by regulating cell proliferation, autophagy, angiogenesis, invasion, and metastasis. As all these processes conjunctively lead to cancer progression, their site-specific regulation might be beneficial for cancer treatment. CTS regulate activation of the proteolytic cascade and protein turnover, while extracellular CTS is involved in promoting extracellular matrix degradation and angiogenesis, thereby stimulating invasion and metastasis. Despite cancer regulation, the involvement of CTS in cellular adaptation toward chemotherapy and radiotherapy augments their therapeutic potential. However, lysosomal permeabilization mediated cytosolic translocation of CTS induces programmed cell death. This complex behavior of CTS generates the need to discuss the different aspects of CTS associated with cancer regulation. In this review, we mainly focused on the significance of each cathepsin in cancer signaling and their targeting which would provide noteworthy information in the context of cancer biology and therapeutics.

Long-term endurance training increases serum cathepsin S levels in healthy female subjects

BACKGROUND

Circulating cathepsin S (CS) has been associated with a lower risk for breast cancer in a large Swedish cohort. Long-term physical activity has been shown to have beneficial effects on the development of various cancer subtypes, in particular breast and colorectal cancers. The aim of this study was to investigate the effect of long-term endurance sport on CS levels in females.

MATERIAL AND METHODS

Thirty-six of 40 subjects completed the study. Subjects were told to increase their activity pensum for 8 months reaching 150 min/week moderate or 75 min/week intense exercise. Ergometries were performed at the beginning and the end of the study to prove/quantify the performance gain. Blood samples were drawn at baseline and every 2 months. Serum CS levels were measured by ELISA. To analyse the change and the progression of CS, Wilcoxon rank sum and Friedman tests were used.

RESULTS

The sportive group (performance gain by > 4.9%) showed a significant increase of CS levels from 3.32/2.73/4.09 to 4.00/3.09/5.04 ng/ml (p = 0.008) corresponding to an increase of 20.5%.

CONCLUSIONS

We could show a significant increase of circulating CS levels in healthy female subjects induced by long-term physical activity. CS, occurring in the tumour microenvironment, is well-known to promote tumour growth, e.g. by ameliorating angiogenesis. However, the role of circulating CS in cancer growth is not clear. As physical activity is known as preventive intervention, in particular concerning breast and colorectal cancers, and long-term physical activity leads to an increase of CS levels in female subjects, circulating CS might even be involved in this protective effect.

TRIAL REGISTRATION

Clinical trial registration: NCT02097199.

Inhibition of cathepsin S confers sensitivity to methyl protodioscin in oral cancer cells via activation of p38 MAPK/JNK signaling pathways

Oral cancer is one of the most common cancers in the world. Approximately 90% of oral cancers are subtyped to oral squamous cell carcinoma (OSCC). Despite advances in diagnostic techniques and improvement in treatment modalities, the prognosis remains poor. Therefore, an effective chemotherapy mechanism that enhances tumor sensitivity to chemotherapeutics is urgently needed. Methyl protodioscin (MP) is a furostanol bisglycoside with a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. The aim of the present study was to determine the antitumor activity of MP on OSCC and its underlying mechanisms. Our results show that treatment of OSCC cells with MP potently inhibited cell viability. Moreover, MP leading to cell cycle arrest at G2/M phase, which subsequently activates caspase-3, -8, -9 and PARP to induce cell apoptosis. Meanwhile, we also demonstrate that MP induces a robust autophagy in OSCC cells. The results indicate cathepsin S (CTSS) is involved in MP-induced apoptosis and autophagy by modulation of p38 MAPK and JNK1/2 pathways. These findings may provide rationale to combine MP with CTSS blockade for the effective treatment of OSCC.

Nidogen-1 Degraded by Cathepsin S can be Quantified in Serum and is Associated with Non-Small Cell Lung Cancer

Loss of basement membrane (BM) integrity is typically associated with cancer. Nidogen-1 is an essential component of the BM. Nidogen-1 is a substrate for cathepsin-S (CatS) which is released into the tumor microenvironment. Measuring nidogen-1 degraded by CatS may therefore have biomarker potential in cancer. The aim of this study was to investigate if CatS-degraded nidogen-1 was detectable in serum and a possible biomarker for cancer, a pathology associated with disruption of the BM. A competitive enzyme-linked immunosorbent assay (NIC) was developed with a monoclonal mouse antibody specific for a CatS cleavage site on human nidogen-1. Dilution and spiking recovery, inter- and intravariation, as well as accuracy were evaluated. Serum levels were evaluated in patients with breast cancer, small cell lung cancer (SCLC), and non-SCLC (NSCLC) and in healthy controls. The results indicated that the NIC assay was specific for nidogen-1 cleaved by CatS. Inter- and intraassay variations were 9% and 14%, respectively. NIC was elevated in NSCLC as compared to healthy controls (P<.001), breast cancer (P<.01), and SCLC (P<.5). The diagnostic power (area under the receiver operating characteristics) of NIC for NSCLC as compared to all other samples combined was 0.83 (95% confidence interval: 0.71-0.95), P<.0001. In conclusion, nidogen-1 degraded by CatS can be quantified in serum by the NIC assay. The current data strongly suggest that cathepsin-S degradation of nidogen-1 is strongly associated with NSCLC, which needs validation in larger clinical cohorts.

Potential Roles of Protease Inhibitors in Cancer Progression

Proteases are important molecules that are involved in many key physiological processes. Protease signaling pathways are strictly controlled, and disorders in protease activity can result in pathological changes such as cardiovascular and inflammatory diseases, cancer and neurological disorders. Many proteases have been associated with increasing tumor metastasis in various human cancers, suggesting important functional roles in the metastatic process because of their ability to degrade the extracellular matrix barrier. Proteases are also capable of cleaving non-extracellular matrix molecules. Inhibitors of proteases to some extent can reduce invasion and metastasis of cancer cells, and slow down cancer progression. In this review, we focus on the role of a few proteases and their inhibitors in tumors as a basis for cancer prognostication and therapy.

A novel approach for reliable detection of cathepsin S activities in mouse antigen presenting cells

Cathepsin S (CTSS) is a eukaryotic protease mostly expressed in professional antigen presenting cells (APCs). Since CTSS activity regulation plays a role in the pathogenesis of various autoimmune diseases like multiple sclerosis, atherosclerosis, Sjögren's syndrome and psoriasis as well as in cancer progression, there is an ongoing interest in the reliable detection of cathepsin S activity. Various applications have been invented for specific detection of this enzyme. However, most of them have only been shown to be suitable for human samples, do not deliver quantitative results or the experimental procedure requires technical equipment that is not commonly available in a standard laboratory. We have tested a fluorogen substrate, Mca-GRWPPMGLPWE-Lys(Dnp)-DArg-NH2, that has been described to specifically detect CTSS activities in human APCs for its potential use for mouse samples. We have modified the protocol and thereby offer a cheap, easy, reproducible and quick activity assay to detect CTSS activities in mouse APCs. Since most of basic research on CTSS is performed in mice, this method closes a gap and offers a possibility for reliable and quantitative CTSS activity detection that can be performed in almost every laboratory.