Serum from rats fed red or yellow tomatoes induces Connexin43 expression independently from lycopene in a prostate cancer cell line.
Epidemiologic studies suggested a protective effect of tomatoes against prostate cancer brought by lycopene, a carotenoid conferring the red colour of tomatoes. However, intervention studies on patients have shown that the preventive effect of tomato was more potent than that of lycopene. The aim of this study was to compare the effects of red tomato, yellow tomato (devoid of lycopene) and lycopene on Connexin43 (Cx43) expression, a protein regulating cell growth, on a prostate cancer cell line expressing the androgen receptor. Cells were incubated with serum from rats fed a control diet (CS) or control diet supplemented with red tomato (RTS), yellow tomato (YTS) or lycopene beadlets (LBS). After exposure of the cells to RTS or YTS for 48h, the expression of Cx43 was significantly increased compared to cells exposed to CS. Whereas LBS effect was not significantly different. The cells incubated with RTS and LBS had similar levels of lycopene, while those incubated with YTS contained no lycopene. These data first show that serum nutritionally enriched with red and yellow tomatoes could up-regulate Cx43 turn-over in PC3AR cells independently from lycopene level. Within the physiological approach used in the present study, it can be concluded that compounds other than lycopene contribute to the preventive effect of tomatoes.
Gitenay
Delphine
D
Unité de Nutrition Humaine, INRA, Centre de Clermont-Ferrand/Theix, 63122 Saint-Genès-Champanelle, France.
Lyan
Bernard
B
Talvas
Jérémie
J
Mazur
Andrzej
A
Georgé
Stéphane
S
Caris-Veyrat
Catherine
C
Rock
Edmond
E
D000818:Animals; D002338:Carotenoids / Q000008:administration & dosage*; D045744:Cell Line, Tumor; D018031:Connexin 43 / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000378:metabolism*; D008297:Male; D010936:Plant Extracts / Q000008:administration & dosage*; D011471:Prostatic Neoplasms / Q000378:metabolism*; D051381:Rats; D044967:Serum / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
D018031:Connexin 43; D010936:Plant Extracts; D002338:Carotenoids; D000077276:Lycopene