Vpliv sočasnega zaviranja katepsinov B in X z obstoječo kemoterapijo na funkcijske lastnosti tumorskih matičnih celic

Arko, Klara (author), Mitrović, Ana (mentor)

Odpornost rakavih celic na konvencionalno kemoterapijo je ena glavnih težav pri zdravljenju raka, ki se odraža v ponovnem pojavu bolezni po zaključenem zdravljenju in nastanku agresivnih oblik raka, ki zmanjšujejo kakovost življenja in skrajšujejo življenjsko dobo pacientov z rakom. Pri kemorezistenci imajo pomembno vlogo tumorske matične celice (TMC), ki so intrinzično odporne na citostatike in preživijo kljub agresivnemu zdravljenju. Med drugim je pri TMC povečano izražanje cisteinskih katepsinov B in X, ki sta udeležena v številnih procesih, povezanih z nastankom in napredovanjem raka. Njuno povečano aktivnost pri raku lahko selektivno reguliramo s specifičnimi nizko molekularnimi zaviralci in preko njih vplivamo na funkcijske lastnosti TMC. V okviru magistrske naloge smo preverili vpliv zaviralcev katepsina B (nitroksolin) in X (spojina Z9) v kombinaciji s konvencionalno kemoterapijo (5-fluorouracil) na funkcijske lastnosti TMC. TMC smo izolirali iz treh celičnih linij raka dojke, ki se razlikujejo po vsebnosti celic s fenotipom TMC (MDA-MB-231, MCF-7 in MCF-10A neoT). Ovrednotili smo vpliv zaviralcev samostojno ali v kombinaciji s kemoterapevtikom na znotrajcelično in zunajcelično razgradnjo DQ-kolagena IV ter vpliv zaviralca katepsina B v kombinaciji s kemoterapevtikom na invazijo TMC. Dobljeni rezultati kažejo, da so zaviralci katepsinov B in X poleg diferenciranih tumorskih celic učinkoviti tudi proti TMC. Pokazali smo, da lahko z uporabo zaviralcev katepsinov zmanjšamo razgradnjo zunajceličnega matriksa TMC in njihovo invazijo. Pri tem rezultati kažejo tudi, da ima sočasno zaviranje katepsina B in X sinergističen učinek na zmanjšanje razgradnje ZCM tudi pri TMC. Nadalje smo pokazali, da lahko s sočasnim zaviranjem katepsinov v kombinaciji s konvencionalno kemoterapijo dosežemo dodatno zmanjšanje razgradnje ZCM in invazije TMC. Uporaba zaviralcev katepsinov B in X s svojim učinkom tudi na TMC tako predstavlja obetaven pristop za premagovanje omejitev obstoječe protitumorne terapije. S sočasno aplikacijo zaviralcev katepsina B in X z obstoječo kemoterapijo lahko tako povečamo učinkovitost obstoječe protitumorne terapije usmerjene proti TMC tudi v procesih, pri katerih so običajni kemoterapevtiki manj učinkoviti.

• Language: Slovenian
• Keywords: Tumorske matične celice, katepsin B, katepsin X, selektivni zaviralci, konvencionalna kemoterapija
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2023
• PID: 20.500.12556/RUL-151666
• Publication date in RUL: 15.10.2023

Secondary language

• Language: English
• Title: The effect of concurrent cathepsin B and X inhibition with conventional chemotherapy on functional properties of cancer stem cells

Abstract

Resistance of cancer cells to conventional chemotherapy is one of the major challenges in cancer treatment, leading to disease recurrence after treatment and the emergence of aggressive cancer forms that reduce patients' quality of life and shorten their lifespan. Cancer stem cells (CSC) play a significant role in chemoresistance, as they are inherently resistant to chemotherapy and can survive aggressive treatments. Among other, in CSC expression of cysteine cathepsins B and X that are involved in numerous processes related to cancer initiation and progression is increased. Their increased activity in cancer can be selectively regulated using specific low-molecular inhibitors that effect the functional properties of CSC. In this master's thesis, we investigated the impact of cathepsin B (nitroxoline) and X (compound Z9) inhibitors in combination with conventional chemotherapy (5-fluorouracil) on the functional properties of CSC. CSC were isolated from three breast cancer cell lines that differ in the proportion of cells with CSC phenotype (MDA-MB-231, MCF-7, and MCF 10A neoT). We evaluated the effects of the inhibitors either alone or in combination with conventional chemotherapy on intracellular and extracellular degradation of DQ-collagen IV, as well as the impact of the cathepsin B inhibitor in combination with chemotherapy on CSC invasion. The obtained results indicate that cathepsin B and X inhibitors are effective not only against differentiated tumor cells but also against CSC. We demonstrated that the use of cathepsin inhibitors can reduce ECM degradation in CSC and their invasion. Furthermore, the results suggest that simultaneous inhibition of cathepsin B and X has a synergistic effect on reducing ECM degradation in CSC. Additionally, we showed that concurrent inhibition of cathepsins in combination with conventional chemotherapy further reduces ECM degradation and CSC invasion. The use of cathepsin B and X inhibitors, with their effect on CSC, represents a promising approach to overcome the limitations of existing antitumor therapy. By concurrently applying cathepsin B and X inhibitors with existing chemotherapy, we can enhance the effectiveness of current CSC targeted antitumor therapy, even in processes where conventional chemotherapeutics are less effective.

• Keywords: Cancer stem cells, cathepsin B, cathepsin X, selective inhibitors, conventional chemotherapy