1. TRIM28 and [beta]-actin identified via nanobody-based reverse proteomics approach as possible human glioblastoma biomarkersIvana Jovchevska, Neja Šamec, Nina Kočevar Britovšek, Daniela Cesselli, Neža Podergajs, Clara Limbaeck Stanic, Michael P. Myers, Serge Muyldermans, Gholamreza Hassanzadeh Ghassabeh, Helena Motaln, Maria Elisabetta Ruaro, Evgenia Bourkoula, Tamara Lah Turnšek, Radovan Komel, 2014, izvirni znanstveni članek Povzetek: Malignant gliomas are among the rarest brain tumours, and they have the worst prognosis. Grade IV astrocytoma, known as glioblastoma multiforme (GBM), is a highly lethal disease where the standard therapies of surgery, followed by radiation and chemotherapy, cannot significantly prolong the life expectancy of the patients. Tumour recurrence shows more aggressive form compared to the primary tumour, and results in patient survival from 12 to 15 months only. Although still controversial, the cancer stem cell hypothesis postulates that cancer stem cells are responsible for early relapse of the disease after surgical intervention due to their high resistance to therapy. Alternative strategies for GBM therapy are thus urgently needed. Nanobodies are single-domain antigen-binding fragments of heavy-chain antibodies, and together with classical antibodies, they are part of the camelid immune system. Nanobodies are small and stable, and they share a high degree of sequence identity to the human heavy chain variable domain, and these characteristics offer them advantages over classical antibodies or antibody fragments. We first immunised an alpaca with a human GBM stem-like cell line prepared from primary GBM cultures. Next, a nanobody library was constructed in a phage-display vector. Using nanobody phage-display technology, we selected specific GBM stem-like cell binders through a number of affinity selections, using whole cell protein extracts and membrane protein-enriched extracts from eight different GBM patients, and membrane protein-enriched extracts from two established GBM stem-like cell lines (NCH644 and NCH421K cells). After the enrichment, periplasmic extract ELISA was used to screen for specific clones. These nanobody clones were recloned into the pHEN6 vector, expressed in Escherichia coli WK6, and purified using immobilised metal affinity chromatography and size-exclusion chromatography. Specific nanobody:antigen pairs were obtained and mass spectrometry analysis revealed two proteins, TRIM28 and β-actin, that were up-regulated in the GBM stem-like cells compared to the controls. Ključne besede: malignant gliomas, cancer stem cells, nanobodies Objavljeno v DiRROS: 02.08.2024; Ogledov: 129; Prenosov: 102 Celotno besedilo (652,32 KB) Gradivo ima več datotek! Več... |
2. Localization patterns of cathepsins K and X and their predictive value in glioblastomaBarbara Breznik, Clara Limbaeck Stanic, Andrej Porčnik, Andrej Blejec, Miha Koprivnikar Krajnc, Roman Bošnjak, Janko Kos, Cornelis J. F. van Noorden, Tamara Lah Turnšek, 2018, izvirni znanstveni članek Povzetek: Background
Glioblastoma is a highly aggressive central nervous system neoplasm characterized by extensive infiltration of malignant cells into brain parenchyma, thus preventing complete tumor eradication. Cysteine cathepsins B, S, L and K are involved in cancer progression and are overexpressed in glioblastoma. We report here for the first time that cathepsin X mRNA and protein are also abundantly present in malignant glioma.
Materials and methods
Gene expression of cathepsins K and X was analyzed using publically-available tran-scriptomic datasets and correlated with glioma grade and glioblastoma subtype. Kaplan-Maier survival analysis was performed to evaluate the predictive value of cathepsin K and X mRNA expression. Cathepsin protein expression was localized and semi-quantified in tumor tissues by immunohistochemistry.
Results
Highest gene expression of cathepsins K and X was found in glioblastoma, in particular in the mesenchymal subtype. Overall, high mRNA expression of cathepsin X, but not that of cathepsin K, correlated with poor patients’ survival. Cathepsin K and X proteins were abundantly and heterogeneously expressed in glioblastoma tissue. Immuno-labeling of cathepsins K and X was observed in areas of CD133-positive glioblastoma stem cells, localized around arterioles in their niches that also expressed SDF-1α and CD68. mRNA levels of both cathepsins K and X correlated with mRNA levels of markers of glioblastoma stem cells and their niches.
Conclusions
The presence of both cathepsins in glioblastoma stem cell niche regions indicates their possible role in regulation of glioblastoma stem cell homing in their niches. The clinical relevance of this data needs to be elaborated in further prospective studies. Ključne besede: cathepsins, glioblastoma, immunohistochemistry, patient survival, cancer stem cell niches Objavljeno v DiRROS: 24.07.2024; Ogledov: 145; Prenosov: 105 Celotno besedilo (1,91 MB) Gradivo ima več datotek! Več... |
3. Cysteine cathepsins B, X and K expression in peri-arteriolar glioblastoma stem cell nichesBarbara Breznik, Clara Limbaeck Stanic, Janko Kos, Mohammed Khurshed, Vashendriya V. V. Hira, Roman Bošnjak, Tamara Lah Turnšek, Cornelis J. F. van Noorden, 2018, izvirni znanstveni članek Povzetek: Glioblastoma (GBM) is the most lethal brain tumor also due to malignant and therapy-resistant GBM stem cells (GSCs) that are localized in protecting hypoxic GSC niches. Some members of the cysteine cathepsin family of proteases have been found to be upregulated in GBM. Cathepsin K gene expression is highly elevated in GBM tissue versus normal brain and it has been suggested to regulate GSC migration out of the niches. Here, we investigated the cellular distribution of cathepsins B, X and K in GBM tissue and whether these cathepsins are co-localized in GSC niches. Therefore, we determined expression of these cathepsins in serial paraffin sections of 14 human GBM samples and serial cryostat sections of two samples using immunohistochemistry and metabolic mapping of cathepsin activity using selective fluorogenic substrates. We detected cathepsins B, X and K in peri-arteriolar GSC niches in 9 out of 16 GBM samples, which were defined by co-expression of the GSC marker CD133, the niche marker stromal-derived factor-1α (SDF-1α) and smooth muscle actin as a marker for arterioles. The expression of cathepsin B and X was detected in stromal cells and cancer cells throughout the GBM sections, whereas cathepsin K expression was more restricted to arteriole-rich regions in the GBM sections. Metabolic mapping showed that cathepsin B, but not cathepsin K is active in GSC niches. On the basis of these findings, it is concluded that cathepsins B, X and K have distinct functions in GBM and that cathepsin K is the most likely GSC niche-related cathepsin of the three cathepsins investigated. Ključne besede: cysteine cathepsins, glioblastoma stem cells, niches, stroma, proteolytic activity Objavljeno v DiRROS: 24.07.2024; Ogledov: 131; Prenosov: 127 Celotno besedilo (10,33 MB) Gradivo ima več datotek! Več... |
4. Localization patterns of cathepsins K and X and their predictive value in glioblastomaBarbara Breznik, Clara Limbaeck Stanic, Andrej Porčnik, Andrej Blejec, Miha Koprivnikar Krajnc, Roman Bošnjak, Janko Kos, Cornelis J. F. van Noorden, Tamara Lah Turnšek, 2018, izvirni znanstveni članek Ključne besede: cathepsins, glioblastoma, immunohistochemistry, patient survival, cancer stem cell niches Objavljeno v DiRROS: 11.06.2024; Ogledov: 143; Prenosov: 119 Celotno besedilo (1,91 MB) |
5. Brain meningioma invading and destructing the skull bone : replacement of the missing bone in vivoTomaž Velnar, Rado Pregelj, Clara Limbaeck Stanic, 2011, izvirni znanstveni članek Povzetek: Background. Meningiomas are frequently encountered tumours. In those invading locally into the adjacent tissue, reconstructions may pose a problem. Case report. We report a case of a benign convexity brain meningioma with invasion into the skull bone and subcutaneous tissue. The tumour was removed completely, together with the infiltrated tissue and the defects were successfully closed with in vivo bone reconstruction. Conclusions. The reconstruction of the skull bone is sometimes needed after the benign meningioma excision. Artificial bone may be a suitable material, allowing fastintraoperative reconstruction with excellent brain protection andcosmetic effect during the one-stage procedure. Objavljeno v DiRROS: 19.03.2024; Ogledov: 248; Prenosov: 139 Celotno besedilo (685,53 KB) Gradivo ima več datotek! Več... |