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1.
Breast Cancer Res ; 12(5): R81, 2010.
Article in English | MEDLINE | ID: mdl-20929592

ABSTRACT

INTRODUCTION: Basic research has indicated that tocotrienols have potent antiproliferative and proapoptotic effects that would be expected to reduce the effect of breast cancer. METHODS: We conducted a double-blinded, placebo-controlled pilot trial to test the effectiveness of adjuvant tocotrienol therapy in combination with tamoxifen for five years in women with early breast cancer. Two-hundred-forty women, aged between 40-60 years, with either tumor node metastases (TNM) Stage I or II breast cancer and estrogen receptor (ER) positive tumors were non-randomly assigned to two groups. The intervention group received tocotrienol rich fraction (TRF) plus tamoxifen whilst the control group received placebo plus tamoxifen, for five years. RESULTS: During the five years of study, 8 patients died due to breast cancer while 36 patients developed local or systemic recurrence. Five-year breast cancer specific survival was 98.3% (95% confidence interval (CI): 95.9% to 100%) in the intervention group and 95%, (95% CI: 91.1% to 98.9%) in the control group, while 5-years disease free survival was 86.7% (95% CI: 80.6% to 92.8%) and 83.3% (95% CI: 76.6% to 90.0%), respectively. Risk of mortality due to breast cancer was 60% (HR: 0.40; 95% CI: 0.08 to 2.05) lower in the intervention group versus the controls following adjustment for age, ethnicity, stage and lymph node status but this was not statistically significant. Adjuvant TRF therapy was not associated with breast cancer recurrence (HR: 0.84; 95% CI: 0.43-1.65). CONCLUSIONS: From the current study, there seems to be no association between adjuvant tocotrienol therapy and breast cancer specific survival in women with early breast cancer. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01157026.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antioxidants/therapeutic use , Breast Neoplasms/drug therapy , Tamoxifen/administration & dosage , Tocotrienols/administration & dosage , Adult , Breast Neoplasms/mortality , Chemotherapy, Adjuvant , Disease-Free Survival , Double-Blind Method , Female , Humans , Middle Aged , Neoplasm Metastasis , Receptors, Estrogen/metabolism , Treatment Outcome
2.
Biol Reprod ; 77(6): 934-41, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17699737

ABSTRACT

Estradiol (E(2)) accelerates oviductal egg transport through intraoviductal nongenomic pathways in cyclic rats and through genomic pathways in pregnant rats. This shift in pathways, which we have provisionally designated as intracellular path shifting (IPS), is caused by mating-associated signals and represents a novel and hitherto unrecognized phenomenon. The mechanism underlying IPS is currently under investigation. Using microarray analysis, we identified several genes the expression levels of which changed in the rat oviduct within 6 hours of mating. Among these genes, the mRNA level for the enzyme catechol-O-methyltransferase (COMT), which produces methoxyestradiols from hydroxyestradiols, decreased 6-fold, as confirmed by real-time PCR. O-methylation of 2-hydroxyestradiol was up to 4-fold higher in oviductal protein extracts from cyclic rats than from pregnant rats and was blocked by OR486, which is a selective inhibitor of COMT. The levels in the rat oviduct of mRNA and protein for cytochrome P450 isoforms 1A1 and 1B1, which form hydroxyestradiols, were detected by RT-PCR and Western blotting. We explored whether methoxyestradiols participate in the pathways involved in E(2)-accelerated egg transport. Intrabursal application of OR486 prevented E(2) from accelerating egg transport in cyclic rats but not in pregnant rats, whereas 2-methoxyestradiol (2ME) and 4-methoxyestradiol mimicked the effect of E(2) on egg transport in cyclic rats but not in pregnant rats. The effect of 2ME on egg transport was blocked by intrabursal administration of the protein kinase inhibitor H-89 or the antiestrogen ICI 182780, but not by actinomycin D or OR486. We conclude that in the absence of mating, COMT-mediated formation of methoxyestradiols in the oviduct is essential for the nongenomic pathway through which E(2) accelerates egg transport in the rat oviduct. Yet unidentified mating-associated signals, which act directly on oviductal cells, shut down the E(2) nongenomic signaling pathway upstream and downstream of methoxyestradiols. These findings highlight a physiological role for methoxyestradiols in the female genital tract, thereby confirming the occurrence of and providing a partial explanation for the mechanism underlying IPS.


Subject(s)
Catechol O-Methyltransferase/physiology , Estradiol/analogs & derivatives , Estradiol/physiology , Oviducts/physiology , Ovum/physiology , 2-Methoxyestradiol , Animals , Aryl Hydrocarbon Hydroxylases/metabolism , Cytochrome P-450 CYP1A1/metabolism , Cytochrome P-450 CYP1B1 , Egg Proteins/biosynthesis , Egg Proteins/metabolism , Estradiol/metabolism , Estrogens, Catechol , Female , Gene Expression Regulation , Menstrual Cycle/physiology , Methylation , Oviducts/metabolism , Ovum/metabolism , Phosphorylation , Pregnancy , Rats , Rats, Sprague-Dawley , Receptors, Estrogen/physiology , Sexual Behavior, Animal/physiology
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