1. Addition of 2-(ethylamino)acetonitrile group to nitroxoline results in significantly improved anti-tumor activity in vitro and in vivoAna Mitrović, Izidor Sosič, Špela Kos, Urša Lampreht Tratar, Barbara Breznik, Simona Kranjc Brezar, Bojana Mirković, Stanislav Gobec, Tamara Lah Turnšek, Maja Čemažar, Gregor Serša, Janko Kos, 2017, izvirni znanstveni članek Povzetek: Lysosomal cysteine peptidase cathepsin B, involved in multiple processes associated with tumor progression, is validated as a target for anti-cancer therapy. Nitroxoline, a known antimicrobial agent, is a potent and selective inhibitor of cathepsin B, hence reducing tumor progression in vitro and in vivo. In order to further improve its anti-cancer properties we developed a number of derivatives using structure-based chemical synthesis. Of these, the 7-aminomethylated derivative (compound 17) exhibited significantly improved kinetic properties over nitroxoline, inhibiting cathepsin B endopeptidase activity selectively. In the present study, we have evaluated its anti-cancer properties. It was more effective than nitroxoline in reducing tumor cell invasion and migration, as determined in vitro on two-dimensional cell models and tumor spheroids, under either endpoint or real time conditions. Moreover, it exhibited improved action over nitroxoline in impairing tumor growth in vivo in LPB mouse fibrosarcoma tumors in C57Bl/6 mice. Taken together, the addition of a 2-(ethylamino)acetonitrile group to nitroxoline at position 7 significantly improves its pharmacological characteristics and its potential for use as an anti-cancer drug.
Ključne besede: nitroxoline derivative, cathepsin B, inhibition, tumor invasion, cell migration
Objavljeno v DiRROS: 26.07.2024; Ogledov: 110; Prenosov: 94
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2. Cathepsin K cleavage of SDF-1[alpha] inhibits its chemotactic activity towards glioblastoma stem-like cellsVashendriya V. V. Hira, Urška Verbovšek, Barbara Breznik, Matic Srdič, Marko Novinec, Hala Kakar, Jill Wormer, Britt van der Swaan, Brigita Lenarčič, Luiz Juliano, Shwetal Mehta, Cornelis J. F. van Noorden, Tamara Lah Turnšek, 2017, izvirni znanstveni članek Povzetek: Glioblastoma (GBM) is the most aggressive primary brain tumor with poor patient survival that is at least partly caused by malignant and therapy-resistant glioma stem-like cells (GSLCs) that are protected in GSLC niches. Previously, we have shown that the chemo-attractant stromal-derived factor-1α (SDF-1α), its C-X-C receptor type 4 (CXCR4) and the cysteine protease cathepsin K (CatK) are localized in GSLC niches in glioblastoma. Here, we investigated whether SDF-1α is a niche factor that through its interactions with CXCR4 and/or its second receptor CXCR7 on GSLCs facilitates their homing to niches. Furthermore, we aimed to prove that SDF-1α cleavage by CatK inactivates SDF-1α and inhibits the invasion of GSLCs. We performed mass spectrometric analysis of cleavage products of SDF-1α after proteolysis by CatK. We demonstrated that CatK cleaves SDF-1α at 3 sites in the N-terminus, which is the region of SDF-1α that binds to its receptors. Confocal imaging of human GBM tissue sections confirmed co-localization of SDF-1α and CatK in GSLC niches. In accordance, 2D and 3D invasion experiments using CXCR4/CXCR7-expressing GSLCs and GBM cells showed that SDF-1α had chemotactic activity whereas CatK cleavage products of SDF-1α did not. Besides, CXCR4 inhibitor plerixafor inhibited invasion of CXCR4/CXCR7-expressing GSLCs.
In conclusion, CatK can cleave and inactivate SDF-1α. This implies that CatK activity facilitates migration of GSLCs out of niches. We propose that activation of CatK may be a promising strategy to prevent homing of GSLCs in niches and thus render these cells sensitive to chemotherapy and radiation.
Ključne besede: glioma stem-like cells, niche, stromal derived factor-[alpha], cathepsin K
Objavljeno v DiRROS: 24.07.2024; Ogledov: 101; Prenosov: 111
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3. Upregulation of cathepsin X in glioblastoma : interplay with γ-enolase and the effects of selective cathepsin X inhibitorsBernarda Majc, Anamarija Habič, Metka Novak, Ana Rotter, Andrej Porčnik, Jernej Mlakar, Vera Župunski, Urša Pečar Fonović, Damijan Knez, Nace Zidar, Stanislav Gobec, Janko Kos, Tamara Lah Turnšek, Anja Pišlar, Barbara Breznik, 2022, izvirni znanstveni članek Ključne besede: glioblastoma, cathepsin X, γ-enolase, tumor microenvironment, glioblastoma stem cells, cathepsin X inhibitors
Objavljeno v DiRROS: 16.07.2024; Ogledov: 98; Prenosov: 90
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4. Inhibition of cathepsin X enzyme influences the immune response of THP-1 cells and dendritic cells infected with Helicobacter pyloriMiha Skvarč, David Štubljar, Andreja Nataša Kopitar, Samo Jeverica, Bojan Tepeš, Janko Kos, Alojz Ihan, 2013, izvirni znanstveni članek Povzetek: Background. The immune response to Helicobacter pylori importantly determines the outcome of infection as well as the success of eradication therapy. We demonstrate the role of a cysteine protease cathepsin X in the immune response to H. pylori infection. Materials and methods. We analysed how the inhibition of cathepsin X influenced the immune response in experiments when THP-1 cells or dendritic cells isolated from patients were stimulated with 48 strains of H. pylori isolated from gastric biopsy samples of patients which had problems with the eradication of bacteria. Results. The experiments, performed with the help of a flow cytometer, showed that the expression of Toll-like receptors (TLRs), especially TLR-4 molecules, on the membranes of THP-1 cells or dendritic cells was higher when we stimulated cells with H. pylori together with inhibitor of cathepsin X 2F12 compared to THP-1 cells or dendritic cells stimulated with H. pylori only, and also in comparison with negative control samples. We also demonstrated that when we inhibited the action of cathepsin X in THP-1 cells, the concentrations of pro-inflammatory cytokines were lower than when THP-1 cell were stimulated with H. pylori only. Conclusions. We demonstrated that inhibition of cathepsin X influences the internalization of TLR-2 and TLR-4. TLR-2 and TLR-4 redistribution to intra-cytoplasmic compartments is hampered if cathepsin X is blocked. The beginning of a successful immune response against H. pylori in the case of cathepsin X inhibition is delayed.
Ključne besede: cathepsin X, macrophage, dendritic cells
Objavljeno v DiRROS: 22.03.2024; Ogledov: 261; Prenosov: 140
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5. Cathepsin X in serum from patients with colorectal cancer: relation to prognosisTjaša Vižin, Ib Jarle Christensen, Hans Jørgen Nielsen, Janko Kos, 2012, izvirni znanstveni članek Povzetek: Background. Up-regulation of lysosomal cysteine protease cathepsin X (Cat X) is associated with disorders of the immune system and neurodegenerative diseases, while its role in the development and progression of cancer is less understood. Enhanced secretion of pro-Cat X was observed in malignant processes, and therefore, the level of total serum Cat X rather than the active enzyme may better reflect the tumour status. Patients and methods. Seventy-seven patients with colorectal cancer (CRC) were included in a retrospective study. Blood samples were collected prior to therapy. Using ELISA, the values of total Cat X were measured in serum. Groups of healthy persons (n=77), patients with adenomas (n=77) and patients with non-neoplastic findings (n=77) were included. Results. Significant differences between the group of colorectal patients and the groups of healthy persons, adenoma patients and patients with non-malignant findings could not be shown (p=0.89). Within the group of CRC, higher levels of total Cat X significantly correlated to shorter overall survival (HR=2.08, 95% CI:1.07-4.05, p=0.028). Conclusions. Total serum Cat X could be a useful prognostic indicator for determining survival of patients with CRC. Increased serum levels of total CatX may reflect more aggressive tumour cell phenotypes and suggest the involvement of Cat X in processes involved in later stages of tumour progression.
Ključne besede: cysteine cathepsins, cathepsin X, colorectal cancer, prognosis, serum biomarker
Objavljeno v DiRROS: 21.03.2024; Ogledov: 262; Prenosov: 128
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7. Cathepsin L in human meningiomasMiha Trinkaus, Andrej Vranič, Vinko V. Dolenc, Tamara Lah Turnšek, 2003, izvirni znanstveni članek Ključne besede: meningioma-pathology, cathepsin L, reverse transcriptase, polymerase chain reaction, neoplasm invasiveness
Objavljeno v DiRROS: 06.02.2024; Ogledov: 337; Prenosov: 80
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8. Carboxypeptidase cathepsin X defines a multifunctional role of gamma-enolase in cancerTjaša Vižin, Anja Pišlar, Ib Jarle Christensen, Hans Jørgen Nielsen, Pika Meško-Brguljan, Janko Kos, 2022, izvirni znanstveni članek Povzetek: Gamma-enolase enzymatic activity is involved in glycolysis, a prevalent process in cancer cell metabolism. Additionally, gamma-enolase has a pro-survival function, exhibited through the active site at the C-terminal end of the molecule. This activity is regulated by cysteine peptidase cathepsin X, which cleaves two amino acids at C-terminal end of gamma-enolase. In clinical practice, the determination of gamma-enolase as a tumour marker does not differ between total, uncleaved and C-terminally cleaved forms. However, levels of uncleaved gamma-enolase alone may provide additional clinical information. In this study we analysed cathepsin X, C- terminally uncleaved and total gamma-enolase in tumour cell lines and sera from 255 patients with colorectal cancer (CRC) by western blot, immunoprecipitation, enzymatic activity, ELISAs and ECLIA. Results show that uncleaved gamma-enolase, rather than total gamma- enolase, exhibits different levels in cells, being the highest in those, derived from metastatic sites or highly invasive tumours. Gamma-enolase is secreted into the extracellular space predominantly as an uncleaved form and levels were congruent to those within the cells. Furthermore, levels of uncleaved gamma-enolase in cells are inversely related to cathepsin X protein level and its enzymatic activity. Uncleaved gamma-enolase is also predominant form in sera of patients with CRC. Both forms exhibit similar stage dependent distribution, with slightly elevated levels in stage IV patients. Higher levels of total gamma-enolase are significantly related to shorter survival in patients with metastatic CRC. Results support evidence of additional pro-survival function of gamma-enolase in cancer. Future studies should focus on analysis of uncleaved gamma-enolase in tumour samples, which may provide additional relations to clinical indicators of disease progression.
Ključne besede: cancer, cathepsin X, cell survival, gamma-enolase, prognosis
Objavljeno v DiRROS: 06.04.2022; Ogledov: 973; Prenosov: 536
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