Učinci askorbinske kiseline na metabolizam matičnih stanica osteosarkoma uzgojenih iz uzoraka tumorskih tkiva bolesnika

doctoral thesis

• Title (english): The effects of ascorbic acid on metabolism of osteosarcoma stem cells grown from patients' tumour tissue samples
• Author: Marijana Šimić Jovičić
• Mentor: Vladimir Trkulja (mentor)
• Mentor: Inga Urlić (komentor)
• Committee member: Tomislav Đapić (predsjednik povjerenstva)
• Committee member: Stjepko Pleština (član povjerenstva)
• Committee member: Srećko Gajović (član povjerenstva)
• Granter: University of Zagreb; School of Medicine; Zagreb
• Defense date and country: 2024-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Clinical Medical Sciences; Orthopedics
• Universal decimal classification (UDC): 617 - Surgery. Orthopaedics. Ophthalmology

Abstract

Stagnacija rezultata liječenja osteosarkoma (OS) ukazuje na potrebu za novim terapijskim metodama. OS se sastoji od različitih staničnih subpopulacija, među kojima su tumorske matične stanice (OS-TMS). Smatra se da OS-TMS imaju sposobnost samobnavljanja i razvijene mehanizme otpornosti na protutumorske lijekove te da su odgovorne za recidiv bolesti. Obzirom na mehanizme otpornosti, OS-TMS je teško uništiti, pa je njihov metabolizam prepoznat kao potencijalna meta terapijskog djelovanja. Smatra se da se tumorske matične stanice, pa tako i OS-TMS, primarno oslanjaju na glikolizu.
Prema prethodnim in vitro studijama, askorbinska kiselina (AK) bi mogla selektivno inducirati apoptozu OS-TMS iz staničnih linija prooksidacijskim djelovanjem na gliceraldehid-3-fosfat dehidrogenazu (GAPDH) i inhibicijom glikolize.
Ovo istraživanje je imalo za cilj ispitati in vitro utjecaj AK na metabolizam OS-TMS izoliranih iz uzoraka tumorskih tkiva izuzetih od triju bolesnika tijekom dijagnostičke biopsije, s ciljem boljeg razumijevanja biološkog fenomena djelovanja AK na OS-TMS. Dodatno smo ispitali utjecaj bazičnog čimbenika rasta fibroblasta (bFGF) kao čimbenika koji se uobičajeno dodaje staničnom mediju pri uzgoju OS-TMS.
Istraživanje nije potvrdilo hipotezu da AK selektivno djeluje na OS-TMS, štoviše ona može i povećati njihovu vijabilnost. U osjetljivih stanica, AK je izazvala apoptozu. OS-TMS nisu pokazale značajno veću razinu oksidacijskog stresa pri primjeni AK. AK je imao utjecaj na prisutnost GAPDH u OS-TMS što ne mora biti povezano s negativnim djelovanjem reaktivnih kisikovih vrsta. Pokazalo se da OS-TMS nisu nužno isključivo glikolitične nego pokazuju metaboličku plastičnost, štoviše, mogu koristiti oksidacijsku fosforilaciju. bFGF je imao utjecaj na varijabilnost dobivenih rezultata.
Rezultati ovog istraživanja upućuju na to da bi za istraživanje djelovanja AK na OS-TMS trebalo koristiti nelinijske stanice i više metoda molekularne biologije čime bi se mogao dobiti cjelovitiji uvid. Također, rezultati sugeriraju da bi AK mogla biti slabo terapijsko sredstvo u eradikaciji OS-TMS kod bolesnika koji prethodno nisu bili izloženi protutumorskom liječenju. Potrebna su daljnja istraživanja učinaka AK na nelinijske stanice OS-a prije nego se ona uvede kao pomoćno terapijsko sredstvo u liječenju oboljelih od OS.

Abstract (english)

Stagnation of osteosarcoma (OS) treatment results indicates the need for new therapeutic methods. OS consists of different cell subpopulations, among which are cancer stem cells (OS-CSCs). It is believed that OS-CSCs have the ability to self-renew and developed mechanisms of resistance to antitumour drugs and are responsible for disease recurrence. Considering the mechanisms of resistance, OS-CSCs are difficult to eradicate, so their metabolism is recognized as a potential target of therapeutic action. OS-CSCs are thought to rely primarily on glycolysis. According to previous in vitro studies, ascorbic acid (AA) could selectively induce apoptosis of OS-CSCs from cell lines by prooxidative effect and inhibition of glycolysis.
The aim of this study was to examine the in vitro effect of AA on the metabolism of OS-CSCs isolated from tumor tissue samples taken from three patients during diagnostic biopsy, with the aim of better understanding the biological phenomenon of the effect of AA on OS-CSCs. Additionally, we examined the influence of bFGF as a factor that is commonly added to the cell medium during OS-CSCs cultivation.
In this study AA induced apoptosis of non-lineage OS-CSCs, but had no selective effect. OS-CSCs did not show a significantly higher level of oxidative stress when treated with AA. OS-CSCs were not necessarily glycolytic but exhibited metabolic plasticity, moreover, they used oxidative phosphorylation despite their stemness. AA decreased the GAPDH in OS-CSCs, which does not have to be necessarily related to the negative effect of reactive oxygen species. bFGF had an impact on the variability of the obtained results.
Relults obtained using different complementary in vitro methods suggest that AK is not a potent therapeutic agent in the eradication of OS-TMS in patients who have not been previously exposed to antitumor treatment. Further research of the effects of AK on non-lineage OS cells is needed before it is introduced as an adjunctive therapeutic agent in the treatment of OS patients.

• Keywords: Oksidativne fosforilacije; Askorbinska kiselina; Oksidativni stres; Osteosarkom; Apoptoza; Glikoliza; Neoplastične matične stanice; Biološki fenomeni
• Keywords (english): Oxidative Phosphorylation; Ascorbic Acid; Oxidative Stress; Osteosarcoma; Apoptosis; Glycolysis; Neoplastic Stem Cells; Biological Phenomena
• Language: croatian
• URN:NBN: urn:nbn:hr:105:450279
• Study programme: Title: Biomedicine and Health Sciences; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje biomedicine i zdravstvo (doktor/doktorica znanosti, područje biomedicine i zdravstvo)
• Type of resource: Text
• Extent: 93 str.
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-07-22 08:50:44