retinamide and Breast-Neoplasms

There are strong data showing that increased breast cancer risk is associated with increased mammographic density. Tamoxifen has been shown to decrease the risk of invasive breast cancer and decrease breast density. We sought to demonstrate and calculate the extent of change in mammographic density in women who have taken tamoxifen for up to 2 years. We evaluated mammograms from 28 high-risk women who were taking tamoxifen. Four different methods of evaluation were used: (a) two qualitative methods (Wolfe criteria and the American College of Radiology Breast Imaging and Reporting Data System criteria); (b) one semiquantitative method (mammograms were assigned one of five semiquantitative scores by visual inspection); and (c) one quantitative method (computer-aided calculation of fibroglandular area from digitized mammograms). The Wolfe criteria showed a 0.03 category decrease per year (P = 0.50). The American College of Radiology Breast Imaging and Reporting Data System criteria showed a 0.1 category decrease per year (P = 0.12). Semiquantitative criteria showed a 0.2 category decrease per year (P = 0.039). Digitized scores showed a 4.3% decrease per year (P = 0.0007). In conclusion, tamoxifen causes a decrease in mammographic density with use, an effect that is better quantitated with semiquantitative criteria or digitized images. Density change might become useful as a surrogate end point for the effect of tamoxifen and other chemopreventive measures, although our data do not predict an individual's degree of risk reduction.

Topics: Adult; Age Factors; Aged; Anticarcinogenic Agents; Antineoplastic Agents; Biomarkers, Tumor; Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Carcinoma, Lobular; Feasibility Studies; Female; Humans; Mammography; Middle Aged; Pilot Projects; Postmenopause; Radiographic Image Enhancement; Reproducibility of Results; Selective Estrogen Receptor Modulators; Tamoxifen; Tretinoin

Surrogate end point biomarkers for risk assessment and efficacy of potential chemopreventive agents are needed to improve the efficiency and reduce the cost of chemoprevention trials. It is imperative to develop the best clinical breast model for translational surrogate end point biomarker studies, especially with respect to accrual feasibility. We have initiated a prospective study to develop biomarkers for tamoxifen and N-[4-hydroxyphenyl] retinamide by administering either a placebo or both drugs for 2-4 weeks to women with ductal carcinoma in situ or early invasive cancers in the interval between the initial diagnostic core biopsy and definitive surgery. The principle end point is pretreatment versus posttreatment tumor levels of Ki-67; a number of other exploratory markers will also be examined. The planned target sample size is 100 patients. Between February 1997 and February 2000, 4514 women who had either an abnormal mammogram or a diagnosed breast cancer were screened for the study. Of these 4514 screened patients, 52 (1%) were registered on the study. Major factors of nonparticipation in the remaining 4462 women were as follows: (a) no evidence of malignancy (2081 patients; 46%); (b) ineligible per protocol criteria (575 patients; 13%); (c) preoperative chemotherapy/tamoxifen (520 patients; 11%); (d) surgery scheduling conflict (360 patients; 8%); (e) outside needle biopsy (221 patients; 5%); (f) no residual disease after excisional biopsy (345 patients; 8%); and (g) second opinion only (123 patients; 3%). Other nonparticipation factors included fine needle aspiration only, refusal, tumor size > 2 cm, and estrogen replacement therapy (35 patients each; 2% each). The protocol was amended in midstudy to allow outside needle biopsy, tumor > 2 cm, and estrogen replacement therapy. Accrual to biomarker (nontherapeutic) protocols with delay in definitive cancer surgery is challenging but feasible. Although some accrual problems remain, we have nonetheless succeeded in recruiting 50% of our target sample size in a 3-year period.

Topics: Adult; Aged; Anticarcinogenic Agents; Antineoplastic Agents; Antineoplastic Agents, Hormonal; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Female; Humans; Middle Aged; Patient Selection; Prospective Studies; Research Design; Risk Assessment; Sensitivity and Specificity; Tamoxifen; Tretinoin

Owing to the pharmacological potential of ATRA (all trans-retinoic acid), a series of retinamides and a 1-(retinoyl)-1,3-dicyclohexylurea compound were prepared by reacting ATRA with long chain alkyl or alkenyl fatty amines by using a 4-demethylaminopyridine (DMAP)-catalyzed N,N¢-dicyclohexylcarbodiimide (DCC) coupling. The successful synthesis of the target compounds was demonstrated using a range of spectroscopic techniques. The cytotoxicity of the compounds was measured along with their ability to induce cell cycle arrest and apoptosis in human cancer cell lines MCF-7 (breast cancer) and HepG2 (liver cancer) and normal human cell line HEK293 (embryonic kidney). The results of cytotoxicity and flow cytometry data showed that the compounds had a moderate to strong effect against MCF-7 and HepG2 cells and were less toxic to HEK293 cells. N-oleyl-retinamide was found to be the most potent anticancer agent and was more effective against MCF-7 cells than HepG2 cells.

Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Cycle Checkpoints; Cell Line; Cell Line, Tumor; Female; HEK293 Cells; Hep G2 Cells; Humans; Liver Neoplasms; MCF-7 Cells; Tretinoin; Urea

The synthetic retinoid N-(4-hydroxphenyl) retinamide (4HPR) has manifold actions, which may contribute to its chemopreventive effects on breast cancer cell growth and progression. A role for ceramide as a stress-response signal is investigated here during the cytotoxic action of 4HPR in MCF-7 cells. N-(4-hydroxphenyl) retinamide induced a dose-dependent decline in cell growth and survival associated with a maximal 10-fold increase in ceramide production at 10 microM. N-(4-hydroxphenyl) retinamide exhibited a greater potency than all-trans retinoic acid (ATRA) on growth inhibition and ceramide production. The synthetic peroxisome proliferator-activated receptors agonist troglitazone (TGZ), but not the native ligand 15-deoxy-delta 12,14-prostaglandin J2, abrogated both these actions of 4HPR but not that of ATRA. The antioxidant N-acetylcysteine mimicked the abrogative effect of TGZ on 4HPR action, while the exogenous oxidant H2O2 also stimulated ceramide production. The inhibitors of de novo ceramide synthesis, fumonisin B1 and myriocin, blocked the ceramide response to 4HPR and partially reversed the apoptotic response, but did not prevent the overall decline in cell survival. The pancaspase inhibitor Z-VAD fmk reduced the decrease in cell survival caused by 4HPR, but did not affect the ceramide response. These findings describe a novel redox-sensitive elevation of ceramide levels associated with the cytotoxic response of breast cancer cells to 4HPR. However, a major mediatory role for this sphingolipid in this context remains equivocal.

Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Division; Cell Survival; Ceramides; Fenretinide; Glucosylceramides; Humans; Oxidation-Reduction; PPAR gamma; Tretinoin; Tumor Cells, Cultured

The synthetic retinoid N-(4-hydroxyphenyl)retinamide [4-HPR (or fenretinide)] has preclinical and clinical preventive activity in breast carcinogenesis. 4-HPR and its metabolites have been shown to accumulate in the mammary tissue of rodents. We assessed levels of 4-HPR and its major metabolite, N-(4-methoxyphenyl)retinamide (4-MPR), in plasma and in normal and neoplastic breast tissue obtained from women treated with 4-HPR.. We randomly assigned 14 women with suspected or very recently diagnosed breast cancer to receive 100, 200, or 300 mg of 4-HPR daily for 3-12 days before scheduled biopsy, lumpectomy, or mastectomy. Using high-performance liquid chromatography, we measured post-4-HPR-treatment concentrations of 4-HPR and 4-MPR in plasma and breast tissue obtained during surgery.. Breast tissue and plasma retinamide (4-HPR plus 4-MPR) concentrations increased significantly with short-term oral administration of 4-HPR. Retinamide levels increased in a linear and dose-related fashion in plasma, whereas they peaked and plateaued at 200 mg/day in breast tissue. The total retinamide concentration in breast tissue exceeded that in plasma at each 4-HPR dose. The highest mean tissue:plasma retinamide ratios were achieved at 200 mg/day: 639.5 +/- 253.8 to 190.6 +/- 91.9 ng/ml (4.8:1) for 4-HPR and 594.4 +/- 201.9 to 130.5 +/- 37.8 ng/ml (6.6:1) for 4-MPR. Plasma retinol levels decreased in association with increasing 4-HPR doses. Two patients experienced grade 1 toxicity at the 300 mg/day dose.. These findings indicate that retinamides preferentially accumulate in human breast tissue (versus plasma). 4-HPR tissue concentrations at 200 mg/d were equivalent to those that inhibit growth and induce apoptosis of breast cancer cells in vitro. Previous clinical and correlative laboratory results suggest that 4-HPR may reduce risk in premenopausal women, who are more prone (than are postmenopausal women) to estrogen receptor (ER)-negative breast cancer development. The present results and previous data (including in vitro 4-HPR activity against ER-negative breast cancer) support further study of 4-HPR in the setting of premenopausal/ER-negative breast cancer prevention.

Topics: Administration, Oral; Adult; Aged; Apoptosis; Breast; Breast Neoplasms; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Female; Fenretinide; Humans; Kinetics; Middle Aged; Random Allocation; Time Factors; Tretinoin

The retinamide, N-(4-hydroxyphenyl)retinamide (4-HPR), has shown promising anti-tumor activity, but it is unclear whether this compound is hydrolyzed to all-trans retinoic acid (atRA) and if so, whether this plays any role in its chemotherapeutic activity. To address this issue, the ability of 4-hydroxybenzylretinone (4-HBR), a carbon-linked analog of 4-HPR, to support growth in vitamin A-deficient (VAD) animals and to activate an atRA-responsive gene in vivo was compared to 4-HPR and atRA. Further, the non-hydrolyzable 4-HBR analog was used to determine whether the presence of the labile amide linkage in 4-HPR is essential for the induction of apoptosis in cultured MCF-7 breast cancer cells. Studies in VAD rats showed that 4-HPR, like atRA, supports animal growth and induces CYP26B1 mRNA expression in lung whereas 4-HBR does not. Analysis of plasma from 4-HPR- and atRA-treated VAD animals revealed the presence of atRA whereas it was not detected in plasma from animals given 4-HBR. To determine whether hydrolysis to atRA is necessary for apoptosis induced by 4-HPR in MCF-7 breast cancer cells, morphological and biochemical assays for apoptosis were performed. 4-HBR, like 4-HPR, induced apoptosis in MCF-7 cells. Apoptosis was not induced even at high concentrations of atRA, showing that 4-HPR and 4-HBR act in cells via a distinct signaling pathway. These results show that although limited hydrolysis of 4-HPR occurs in vivo, the ability to liberate atRA is not required for these 4-hydroxyphenyl retinoids to induce apoptosis in MCF-7 breast cancer cells. Thus the non-hydrolyzable analog, 4-HBR, may have significant therapeutic advantage over 4-HPR because it does not liberate atRA that can contribute to the adverse side effects of drug administration in vivo.

Topics: Administration, Oral; Animals; Apoptosis; Body Weight; Breast Neoplasms; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Fenretinide; Humans; Hydrolysis; Male; Rats; Rats, Sprague-Dawley; Tretinoin; Vitamin A; Vitamin A Deficiency