Resveratrol induces cell death in colorectal cancer cells by a novel pathway involving lysosomal cathepsin D.
In human colorectal cancer cells, the polyphenol resveratrol (RV) activated the caspase-dependent intrinsic pathway of apoptosis. This effect was not mediated via estrogen receptors. Pepstatin A, an inhibitor of lysosomal cathepsin D (CD), not (2S,3S)-trans-epoxysuccinyl-L-leucylamido-3-methylbutane ethyl ester, an inhibitor of cathepsins B and L, prevented RV cytotoxicity. Similar protection was attained by small interference RNA-mediated knockdown of CD protein expression. RV promoted the accumulation of mature CD, induced lysosome leakage and increased cytosolic immunoreactivity of CD. Inhibition of CD or its post-transcriptional down-regulation precluded Bax oligomerization, permeabilization of mitochondrial membrane, cytosolic translocation of cytochrome c, caspase 3 activation and terminal deoxinucleotidyl transferase-mediated dUTP-biotin nick end labeling positivity occurring in RV-treated cells. The present study identifies the lysosome as a novel target of RV activity and demonstrates a hierarchy of the proteolytic pathways involved in its cytotoxic mechanism in which the lysosomal CD acts upstream of the cytosolic caspase activation. Our data indicate that metabolic, pharmacologic or genetic conditions affecting CD expression and/or activity could reflect on the sensitivity of cancer cells to RV.
Trincheri
Nicol F
NF
Laboratorio di Patologia Molecolare, Dipartimento di Scienze Mediche, Università del Piemonte Orientale A. Avogadro, Via Solaroli 17, 28100 Novara, Italy.
Nicotra
Giuseppina
G
Follo
Carlo
C
Castino
Roberta
R
Isidoro
Ciro
C
D061945:Caspase Inhibitors; D002402:Cathepsin D / Q000378:metabolism*; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D003546:Cysteine Endopeptidases / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019073:HT29 Cells; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D013997:Time Factors
D061945:Caspase Inhibitors; D013267:Stilbenes; D045304:Cytochromes c; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L; D002402:Cathepsin D; D000077185:Resveratrol