Autophagosomal Sequestration of Mitochondria as an Indicator of Antiandrogen Therapy Resistance of Prostate Cancer (PCa)
Technical Report,01 Nov 2016,31 Oct 2017
The University of Texas MD Anderson Cancer Center Houston United States
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Purpose We have investigated if sequestration of metabolically dysfunctional mitochondria by the autophagosomes mitophagy imparts anti-androgen resistance. Method Effects of the anti-androgen enzalutamide on the autophagy and mitophagy of androgen-dependent LNCaP and independent C4-2 cells are studied first. Autophagy is monitored by cellular fluorescence incells treated with monodansylcadavarine MDC or stained with anti-LC3B antibody. Cellular fluorescence due to Mitosox dye oxidation is used to identify mitochondria producing high superoxide O2-. Mitophagy is monitored using fluorescence resonance energy transfer FRET by visualization of FRET images and quantitation of FRET image intensities using a Nikon A1 or a Leica Di8 fluorescence confocal microscope and Image J software. Results and Discussion Our data show that the degree of mitophagy is more in androgen-dependent LNCaP cells than in independent C4-2 cells, both growing in androgen-depleted media. Enzalutamide treatment induces mitophagy in both cell lines, but the increase in mitophagy is more pronounced in the enzalutamide-resistant C4-2 than in the sensitive LNCaP cells. Mitophagy in circulating tumor cells CTCs isolated from patient blood samples are currently being standardized.
- Medicine and Medical Research