Autophagosomal Sequestration of Mitochondria as an Indicator of Antiandrogen Therapy Resistance of Prostate Cancer (PCa)
Abstract
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2017
- Accession Number
- AD1049237
Entities
People
- George Wilding
Organizations
- University of Texas at Austin