Omega-3 DHA- and EPA-dopamine conjugates induce PPARγ-dependent breast cancer cell death through autophagy and apoptosis.
BACKGROUND
The omega-3 docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) may form conjugates with amines that have potential health benefits against common diseases including cancers. Here we synthesized DHA-dopamine (DHADA) and EPA-dopamine (EPADA) conjugates and studied their biological effects on different breast cancer cell lines.


RESULTS
MTT assays indicated that increasing concentrations of DHADA and EPADA significantly affected viability in MCF-7, SKBR3 and MDA-MB-231 breast cancer cells, whereas no effect was observed in MCF-10A non-tumorigenic epithelial breast cells. DHADA and EPADA enhanced Beclin-1 expression, as evidenced by immunoblotting, real-time-PCR and functional analyses. Chromatin Immunoprecipitation (ChIP) and Re-ChIP assays revealed that both compounds induced recruitment of Peroxisome-Proliferator-Activated-Receptor gamma (PPARγ) and RNA Polymerase-II at the Retinoic-X-Receptor binding region on Beclin-1 promoter. Moreover, both compounds enhanced autophagosome formation, evaluated by LC-3 and monodansylcadaverine labeling, that was prevented by the PPARγ antagonist GW9662, addressing the direct involvement of PPARγ. Noteworthy, long-term treatment with DHADA and EPADA caused the blockade of autophagic flux followed by apoptotic cell death as evidenced by PARP cleavage and DNA fragmentation in all breast cancer cells.


CONCLUSIONS
We have provided new insights into the molecular mechanism through which PPARγ, as a central molecule in the cross talk between autophagy and apoptosis, mediates DHADA- and EPADA-induced cell death in breast cancer cells.


CONCLUSIONS
Our findings suggest that omega-3 DHADA- and EPADA activation of PPARγ may assume biological relevance in setting novel adjuvant therapeutic interventions in breast carcinoma.
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy.
Daniela
D
Rovito
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy.
Cinzia
C
Giordano
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy.
Pierluigi
P
Plastina
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy; Centro Sanitario, University of Calabria, Arcavacata di Rende (CS), Italy.
Ines
I
Barone
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy; Centro Sanitario, University of Calabria, Arcavacata di Rende (CS), Italy.
Francesca
F
De Amicis
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy.
Loredana
L
Mauro
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy.
Pietro
P
Rizza
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy; Centro Sanitario, University of Calabria, Arcavacata di Rende (CS), Italy.
Marilena
M
Lanzino
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy; Centro Sanitario, University of Calabria, Arcavacata di Rende (CS), Italy.
Stefania
S
Catalano
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy; Centro Sanitario, University of Calabria, Arcavacata di Rende (CS), Italy. Electronic address: daniela.bonofiglio@unical.it.
Daniela
D
Bonofiglio
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende (CS), Italy; Centro Sanitario, University of Calabria, Arcavacata di Rende (CS), Italy. Electronic address: sebastiano.ando@unical.it.
Sebastiano
S
Andò
D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics; D001343:Autophagy / Q000187:drug effects*; D000071186:Beclin-1; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D004298:Dopamine / Q000494:pharmacology*; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D008565:Membrane Proteins / Q000235:genetics; D047495:PPAR gamma / Q000502:physiology*; D011401:Promoter Regions, Genetic
D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D008565:Membrane Proteins; D047495:PPAR gamma; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D004298:Dopamine
Apoptosis; Autophagy; Beclin-1; Breast cancer; Omega-3 polyunsaturated fatty acid conjugates; Peroxisome Proliferator-Activated Receptor gamma