Povezave med lipidnimi kapljicami, avtofagijo in feroptozo pri odgovoru rakavih celic na presnovni stres

Perne, Leja (author), Petan, Toni (mentor)

Feroptoza je nedavno odkrita oblika nadzorovane celične smrti, ki bi jo morda lahko izkoriščali za zdravljenje nekaterih oblik raka. Lipidne kapljice (LK) in avtofagija vplivajo na celično porazdelitev polinenasičenih maščobnih kislin (MK), ki so nujne za izvedbo feroptoze. Vlogo LK pri obrambi celic pred feroptozo smo preučili ob spodbujanju biogeneze LK s polinenasičenimi MK in njenem zaviranju s farmakološko inhibicijo diacilglicerol aciltransferaz (DGAT). Feroptozo smo v celicah sprožili s spojino RSL3 in jo inhibirali s ferrostatinom-1, avtofagijo pa zavrli z bafilomicinom A1. Z uporabo konfokalne mikroskopije, pretočne citometrije in imunodetekcije proteinov po prenosu western smo ugotovili, da polinenasičene MK niso le nujne za feroptozo, ampak jo v visokih koncentracijah tudi inducirajo. Feroptotski stres je v celicah raka dojke sprožil z DGAT-posredovano biogenezo LK in znižal avtofagni fluks. Feroptotski stres pa ni vplival na količino adipozne triglicerid lipaze (ATGL), glavnega lipolitičnega encima odgovornega za razgradnjo LK. Pokazali smo, da inhibicija biogeneze LK zviša, inhibicija avtofagije pa v določenih pogojih zniža občutljivost celic raka dojke na feroptozo. Naše delo bo pomembno prispevalo k razumevanju povezav med LK, avtofagijo in feroptozo z namenom razvoja novih pristopov za zmanjšanje odpornosti rakavih celic na stres.

• Language: Slovenian
• Keywords: rak dojke, celična kultura, celični stres, lipidne kapljice, avtofagija, feroptoza, maščobne kisline, stradanje
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [L. Perne]
• Year: 2022
• PID: 20.500.12556/RUL-139735
• UDC: 576
• COBISS.SI-ID: 120871683
• Publication date in RUL: 07.09.2022

PERNE, Leja, 2022, Povezave med lipidnimi kapljicami, avtofagijo in feroptozo pri odgovoru rakavih celic na presnovni stres [online]. Master’s thesis. Ljubljana : L. Perne. [Accessed 5 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=139735

Secondary language

• Language: English
• Title: The link between lipid droplets, autophagy and ferroptosis in the cancer cell response to metabolic stress

Abstract

Ferroptosis is a recently discovered form of regulated cell death that could be potentially used for anti-cancer therapy. Lipid droplets (LDs) and autophagy modulate the cellular distribution of polyunsaturated fatty acids (FAs), which are required for the execution of ferroptosis. Here, we investigated the role of LDs in breast cancer cells under ferroptotic conditions by promoting and inhibiting LD biogenesis with polyunsaturated FAs and pharmacological inhibitors of diacylglycerol acyltransferase (DGAT), respectively. Ferroptosis was induced with RSL3, inhibited with ferrostatin-1, and autophagy was blocked with bafilomycin A1. Using confocal microscopy, flow cytometry and protein immunodetection, we found that polyunsaturated FAs are not only required for ferroptosis, but they also induce ferroptosis in high concentrations. Ferroptotic stress induced DGAT-mediated LD biogenesis and decreases autophagic flux, but did not affect the expression of adipose triglyceride lipase (ATGL), the rate-limiting enzyme involved in LD lipolysis. We showed that inhibition of LD biogenesis increases, whereas inhibition of autophagy, at least in certain conditions, decreases the sensitivity of breast cancer cells to ferroptosis. Our work will contribute to the understanding of the connections between LDs, autophagy and ferroptosis and could help develop new strategies to reduce the resistance of cancer cells to stress.

• Keywords: breast cancer, cell culture, cellular stress, lipid droplets, autophagy, ferroptosis, fatty acids, starvation