Kruisbloemige groenten tegen kanker*
Uit een studie, weliswaar met muizen blijkt dat fenthylisothiocyanaat, een bioactieve stof in o.m.
in diverse kool, waterkers en mosterdzaad de groei van borstkankertumoren sterk kan verminderen. Uit het onderzoek blijkt de manier waarop dit bij de muizen gebeurt vergelijkbaar is als dat bij
mensen gebeurt.
Plant-Based Compound Slows Breast Cancer in a Mouse Model
The natural plant compound phenethyl isothiocyanate (PEITC) hinders the development of mammary tumors in a mouse model with similarities to human breast cancer progression, according to a study published in the Journal of the National Cancer Institute.
Edible plants are gaining ground as chemopreventative agents. PEITC has shown to be effective as a chemopreventative agent in mice for colon, intestinal, and prostate cancer, by inducing apoptosis.
In order to determine the efficacy of PEITC in mammary tumors in mice, Shivendra V. Singh, Ph.D., of the University of Pittsburgh Cancer Institute and colleagues, placed mice on two diets: a control diet, and a diet supplemented with PEITC for 29 weeks. The researchers performed histopathological assessments, and measured the incidence and size of the mammary tumors, along with cell proliferation, apoptosis, and neoangiogenesis, which were determined in tumor sections.
The researchers found that administering PEITC for 29 weeks was linked with a 56.3% reduction in mammary carcinoma lesions greater than 2mm. "Although PEITC administration does not confer complete protection against mammary carcinogenesis, mice placed on the PEITC-supplemented diet, compared with mice placed on the control diet, clearly exhibited suppression of carcinoma progression," the authors write. PEITC was also well-tolerated. Since chemoprevention trials are both expensive and time-consuming and necessitate years of follow-up, the authors feel that, "The discovery of biomarker(s) associated with exposure and activity is critical for clinical development of promising cancer chemopreventative agents." This study was able to identify certain biomarkers that may be useful in future clinical investigations.
The authors also point out certain limitations of their study, namely that the results may be different in humans than in mice; also both the relevance of other altered proteins from PEITC and the mechanism by which PEITC causes apoptosis are unclear.
Methods Female mouse mammary tumor virus–neu mice were fed a control AIN-76A diet (n = 35) or the same diet supplemented with 3 µmol PEITC/g diet (n = 33) for 29 weeks, at which time they were killed. Breast tissue sections were stained with hematoxylin and eosin for histopathological assessments, and incidence and size of macroscopic mammary tumors were assessed. Cell proliferation (Ki-67 staining), apoptosis (terminal deoxynucleotidyl transferase–mediated dUTP nick-labeling), and neoangiogenesis (CD31 staining) were determined in tumor sections. Plasma levels of transthyretin were measured in treated and control mice. Expression of proteins in mammary tumor sections was
determined by immunohistochemistry. Proteomic profiling was performed by two-dimensional gel electrophoresis followed by mass spectrometry. All statistical tests were two-sided.
Results Administration of PEITC for 29 weeks was associated with 53.13% decreased incidence of macroscopic mammary tumors (mean tumor incidence, PEITC-supplemented diet vs control diet, 18.75% vs 40.00%, difference = –21.25%, 95% confidence interval [CI] = –43.19% to 0.69%, P = .07) and with a 56.25% reduction in microscopic mammary carcinoma lesions greater than 2mm2 (mean incidence, PEITC-supplemented diet vs control diet, 18.75% vs 42.86%, difference = –24.11%, 95% CI = –46.35% to –1.86%, P = .04). PEITC-mediated mammary cancer growth inhibition was not because of suppression of human epidermal growth factor receptor-2 expression but was associated with reduced cellular proliferation and neoangiogenesis, increased apoptosis, and altered expression of several proteins, including decreased ATP synthase in the tumor and increased plasma levels of transthyretin.
Conclusions PEITC inhibits the growth of mammary cancers in a mouse model with similarities to human breast cancer progression. ATP synthase and transthyretin appear to be novel biomarkers associated with PEITC
exposure. (Oktober 2012)
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