BACKGROUND: Androgen deprivation therapy, one of the standard treatments for prostate cancer (PCa) induces apoptosis, as well as autophagy in androgen-responsive PCa cells.
As autophagy can promote either cell survival or death, it is important to understand its role in PCa treatment. The objective of this study was to elucidate the function of autophagy in lipid droplet (LD) homeostasis and survival in androgen-sensitive PCa cells.
METHODS: To produce androgen deprivation, charcoal filtered serum or the androgen inhibitor casodex were used in LNCaP and LAPC4 cells. Autophagy was monitored by immunofluorescence/confocal microscopy and immunoblot analysis. Levels of intracellular LDs and triacyglycerols after the inhibition of autophagy by 3-methyladenine, bafilomycin A(1) , or si-ATG5 were quantified by three independent methods, Oil Red O staining, triacyglycerols lipase assay, and nuclear magnetic resonance.
RESULTS: Androgen deprivation induced autophagy and the depletion of LDs in both of the androgen-sensitive PCa cell lines examined, whereas the blockage of autophagy by pharmacological or genetic means inhibited LD degradation and therefore lipolysis and cell growth. In addition, under androgen deprivation, increased colocalization of LDs and autophagic vesicles was observed in LNCaP cells, which can be further enhanced by blocking the autophagic flux.
CONCLUSION: Autophagy mediates LD degradation and lipolysis in androgen-sensitive PCa cells during androgen deprivation which aids the survival of PCa cells during hormone therapy.
Written by:
Kaini RR, Sillerud LO, Zhaorigetu S, Hu CA. Are you the author?
Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico.
Reference: Prostate. 2012 Jan 31.
doi: 10.1002/pros.22489. [Epub ahead of print]
PubMed Abstract
PMID: 22294520
UroToday.com Investigational Urology Section
