Resveratrol-induced apoptosis in human breast cancer cells is mediated primarily through the caspase-3-dependent pathway.
BACKGROUND
Resveratrol (RSVL), a nontoxic natural compound found in a wide variety of plants with known antioxidant and anti-inflammatory properties, is emerging as a potent chemopreventive and anticancer drug. Recently, we demonstrated that RSVL-induced apoptosis in several human cancer cell lines was associated with cleavage of the proapoptotic 116 kDa poly(ADP-ribose) polymerase protein (PARP) into its 89-kDa fragment.


METHODS
Western blotting was used to check the levels of caspase-3 and PARP proteins. The caspase activity was analyzed with the caspase-3 colorimetric substrate DEVD-pNA. Apoptotic cells were quantified by annexin V-FITC-propidium iodide double staining.


RESULTS
We show that RSVL cleaved the immature caspase-3 (35 kDa) into the active fragments (p12, p17, p20) in a dose- and time-dependent manner. In addition, RSVL markedly increased caspase-3 activity (5-fold) in cells. Interestingly, RSVL-induced PARP cleavage and apoptosis was blocked specifically by inhibiting caspase-3.


CONCLUSIONS
Collectively, the data suggest that caspase-3 activation by RSVL is required for PARP degradation and induction of apoptosis in MDA-MB-231 cells and provide additional insights into the action of RSVL, thus substantiating the chemopreventive potential of RSVL against human breast cancer.
Alkhalaf
Moussa
M
Department of Biochemistry, Faculty of Medicine, Kuwait University, Safat, Kuwait. alkhalaf@hsc.edu.kw
El-Mowafy
Abdulla
A
Renno
Waleed
W
Rachid
Ousama
O
Ali
Ahmed
A
Al-Attyiah
Rajaa
R
D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology* / Q000627:therapeutic use
D000975:Antioxidants; D013267:Stilbenes; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D053148:Caspase 3; D000077185:Resveratrol