Vloga kemokina CCL5 in njegovega receptorja CCR5 ter nove možnosti zdravljenja glioblastoma

Koprivnikar Krajnc, Miha (avtor), Lah Turnšek, Tamara (mentor)

Glioblastom (GBM) je rak, ki nastane predvidoma iz astrocitov, z najslabšo prognozo med vsemi, tudi možganskimi raki – v povprečju med 14 do 16 mesecev – in je med temi tudi najbolj pogost. Veliko raziskav se osredotoča na iskanje učinkovitejših možnosti zdravljenja, zato smo v tem delu raziskali vlogo in mehanizme delovanja kemokina CCL5 in njegovega receptorja CCR5 pri GBM. Kemokini so funkcionalna družina citokinov, ki sprožijo kemotakso in so odgovorni za migracijo, tj. usmerjeno gibanje, in infiltracijo imunskih celic, v kontekstu raka pa tudi tumorskih celic. CCL5 in CCR5 imata dokazano pro-tumorsko vlogo pri mnogih vrstah raka, tudi pri GBM, a tu njuna vloga in način medcelične signalizacije še nista bila razjasnjena. Z imunofluorescenco smo na tkivnih rezinah GBM proučili kolokalizacijo med proteini, ki so označevalci določenih zvrsti celic v tumorju in kemokina CCL5 in/ali receptorja CCR5. Ugotovili smo, da CCR5 izražajo tudi GBM matične celice (GSC), kar nakazuje specifične parakrine in avtokrine mehanizme signalizacije. Osredotočili smo se tudi na proučevanje invazivnosti celic GBM v sokulturi z mezenhimskimi matičnimi celicami (MSC) in dokazali signifikantno povečanje invazivnosti tumorskih celic. Ta invazivnost je bila tudi posledica signalizacije CCL5/CCR5 med GBM in MSC celicami, saj je bila po dodatku antagonista receptorja CCR5 znatno inhibirana. Kot antagonist smo uporabili spojino maraviroc (MRV), ki je sicer že odobrena učinkovina za zdravljenje pri okužbi z virusom HIV. Poleg izločane oblike citokina CCL5 smo z mikroskopsko analizo GBM tkivih rezin CCL5 zaznali tudi v jedru. Z bioinformatsko analizo potencialne vloge CCL5 v jedru smo ugotovili, da obstaja podlaga za morebitno vezavo proteina CCL5 na molekulo DNA. Pomen naše raziskave je morebitno izboljšanje oz. kombinirano zdravljenje GBM; učinkovitost sedanjih pristopov (operacija, obsevanje, kemoterapija, imunoterapija) bi namreč lahko učinkovito izboljšali z uporabo oz. repozicioniranjem MRV za dodatno zdravljenje GBM, ki inhibira os CCL5/CCR5 in posledično inhibira od strome odvisno invazijo celic GBM.

• Jezik: Slovenski jezik
• Ključne besede: Glioblastom, glioblastomske matične celice, invazija, kemokini, maraviroc, mezenhimske matične celice, repozicioniranje zdravilnih učinkovin, tumorsko mikrookolje
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Leto izida: 2020
• PID: 20.500.12556/RUL-120542
• COBISS.SI-ID: 33759491
• Datum objave v RUL: 22.09.2020

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: The role of chemokine CCL5, its receptor CCR5 and new therapy potentials in glioblastoma

Izvleček

Glioblastoma (GBM) is a cancer that presumably originates from astrocytes, and is the most common brain cancer and a cancer with the worst prognosis of all – on average 14-16 months. Many studies seek to find ways to improve GBM therapy, which was also the motivation for our research on the role and mechanism of action of chemokine CCL5 and its cognate receptor CCR5 in GBM. Chemokines are a functionally distinct family of cytokines that induce chemotaxis and are responsible for physiological cell migration and immune cell trafficking, as well as tumour cell migration in cancer. CCL5 and CCR5 are proven to have pro-tumour roles in many cancers, including GBM, but the exact role and cell cross-talk mechanism have not yet been determined. Using immunofluorescence on GBM tissue slides, we studied the colocalization of proteins that are markers of various cel types within the tumour and CCL5 and CCR5; we observed that also GBM stem cells (GSC) express CCR5, which indicates specific paracrine and autocrine signalisation mechanisms. Our work was also focused on the studying of the invasivness of GBM cell in coculture with MSC cells and we have proven a significant increase in tumour cell invasiveness. The invasiveness was a result of the CCL5/CCR5 signalisation between GBM cells and mesenchymal stem cells (MSC), as the adding of the CCR5 receptor antagonist Maraviroc caused it to be notably inhibited. Maraviroc is already an approved drug used in the therapy of HIV patients. Along the secreted form of CCL5, using microscopic analysis we observed CCL5 also in the nucleus. Our bioinformatic analysis of the potential role of CCL5 in the nucleus has shown a basis for the possible DNA-binding ability of CCL5. The role of our findings is possibly a better GBM therapy; the effectiveness of current methods (surgery, radiation, chemo- and immunotherapy) could be effectively improved with repositioning MRV for an additional GBM therapy, which inhibits the CCL5/CCR5 axis and consequently inhibits the stroma-induced GBM cell invasion.

• Ključne besede: Glioblastoma, glioblastoma stem cells, invasion, chemokines, maraviroc, mesenchymal stem cells, drug repositioning, tumour microenvironment