Increased ceramide accumulation correlates with downregulation of the autophagy protein ATG-7 in MCF-7 cells sensitized to photodamage.

Archives of Biochemistry and Biophysics
Duska SeparovicJacek Bielawski

Abstract

The purpose of this study was to determine the sphingolipid (SL) profile in cells defective in autophagy protein ATG-7 and overall cell death after photodynamic therapy (PDT) with the photosensitizer Pc 4. MCF-7 human breast cancer cells with downregulated ATG-7 and their scrambled controls (Scr) were used. Exposure of ATG-7 knockdown cells to PDT led to increased cell killing. PDT evoked an early (2h) greater global increase in ceramides in ATG-7 defective cells compared to Scr cells. The total increases in dihydroceramide (DHceramide) were significant at 2 and 24h in both cell types post-PDT. The levels of sphingosine-1-phosphate (S1P) and sphingosine were decreased below resting levels at both time points irrespective of the cell type. The data imply that ceramide might be a marker of ATG-7 deficiency in cells sensitized to PDT.

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Citations

Aug 6, 2013·Journal of Photochemistry and Photobiology. B, Biology·Mladen KorbelikDuska Separovic
Dec 14, 2012·Nature Reviews. Cancer·Samy A F Morad, Myles C Cabot
Dec 3, 2011·Progress in Lipid Research·Sabine GröschGerd Geisslinger
Aug 25, 2015·Biogerontology·David W RussKatherine W McCorkle
Jun 14, 2016·Biochemical and Biophysical Research Communications·Yajuan ZhouXiaoyi Zhou
Mar 5, 2013·International Journal of Molecular Sciences·Rouba Hage-SleimanGhassan Dbaibo
Feb 11, 2015·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·Abhishek D GargPatrizia Agostinis
Oct 6, 2018·Apoptosis : an International Journal on Programmed Cell Death·Xian DuanJun He
Oct 1, 2010·Current Opinion in Rheumatology

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