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The design of a randomized pilot trial evaluating the feasibility of two doses of a digital health intervention promoting changes in nutrition and physical activity in breast cancer (BC) survivors is described.Eligible women were adults with history of early-stage breast cancer and 60 days post-treatment, consumed5 servings/day of fruits/vegetables and/or engaged in150 min/week of aerobic moderate-to-vigorous physical activity, and had internet access. Participants were randomized to 6 months of either a "low" (1 session) or "high" (12 sessions) dose digital health intervention. Zoom-delivered sessions focused on improving diet and physical activity through didactic and experiential classes delivered by a registered dietitian, chef, exercise physiologist, and culinary educator. All study participants received weekly motivational texts, a Fitbit, and study website access. Diet, accelerometry, anthropometric, psychosocial, and biospecimen data were collected remotely at baseline and six months. Primary outcome was feasibility measured via accrual rate, adherence, retention, and acceptability.Recruitment began in December 2019, was suspended in March 2020 due to the COVID-19 pandemic, resumed September 2020, and concluded in January 2021. Women were identified from the local BC registry and flyers posted in the oncology clinic. Of 929 women recruited, 321 completed the screening assessment, and of these, 138 were eligible. A total of 74 women were enrolled and randomized to the study.BC survivors were successfully enrolled in a digital health nutrition and physical activity intervention. If feasible, this intervention will be tested in larger and more diverse populations of cancer survivors.ClinicalTrials.govNCT04200482.

Triple-negative breast cancer (TNBC) comprises ∼20% of all breast cancers and is the most aggressive mammary cancer subtype. Devoid of the estrogen and progesterone receptors, along with the receptor tyrosine kinase ERB2 (HER2), that define most mammary cancers, there are no targeted therapies for patients with TNBC. This, combined with a high metastatic rate and a lower 5-year survival rate than for other breast cancer phenotypes, means there is significant unmet need for new therapeutic strategies. Herein, the anti-neoplastic effects of the electrophilic fatty acid nitroalkene derivative, 10-nitro-octadec-9-enoic acid (nitro-oleic acid, NO2-OA), were investigated in multiple preclinical models of TNBC. NO2-OA reduced TNBC cell growth and viability in vitro, attenuated TNFα-induced TNBC cell migration and invasion, and inhibited the tumor growth of MDA-MB-231 TNBC cell xenografts in the mammary fat pads of female nude mice. The up-regulation of these aggressive tumor cell growth, migration, and invasion phenotypes is mediated in part by the constitutive activation of pro-inflammatory nuclear factor κB (NF-κB) signaling in TNBC. NO2-OA inhibited TNFα-induced NF-κB transcriptional activity in human TNBC cells and suppressed downstream NF-κB target gene expression, including the metastasis-related proteins intercellular adhesion molecule-1 and urokinase-type plasminogen activator. The mechanisms accounting for NF-κB signaling inhibition by NO2-OA in TNBC cells were multifaceted, as NO2-OA (a) inhibited the inhibitor of NF-κB subunit kinase β phosphorylation and downstream inhibitor of NF-κB degradation, (b) alkylated the NF-κB RelA protein to prevent DNA binding, and (c) promoted RelA polyubiquitination and proteasomal degradation. Comparisons with non-tumorigenic human breast epithelial MCF-10A and MCF7 cells revealed that NO2-OA more selectively inhibited TNBC function. This was attributed to more facile mechanisms for maintaining redox homeostasis in normal breast epithelium, including a more favorable thiol/disulfide balance, greater extents of multidrug resistance protein-1 (MRP1) expression, and greater MRP1-mediated efflux of NO2-OA–glutathione conjugates. These observations reveal that electrophilic fatty acid nitroalkenes react with more alkylation-sensitive targets in TNBC cells to inhibit growth and viability.

Multiple strategies for endocrine treatment of premenopausal women with hormone-responsive breast cancer have been assessed and results have been presented over the last two years. These include tamoxifen for 5-10 years (ATLAS and aTTom), tamoxifen for 5 years followed by aromatase inhibitor (AI) for 5 years for women who have become postmenopausal (MA-17); ovarian ablation (OA) by surgery (EBCTCG overview); ovarian function suppression (OFS) by LHRH agonist (LHRH agonist meta-analysis); or combinations of approaches including OFS plus tamoxifen or AI (SOFT, TEXT, ABCSG 12 and E3193). Many of these trials have taken place in the backdrop of (neo)adjuvant chemotherapy which can confound interpretation because such therapy can suppress ovarian function either transiently or permanently. Nonetheless these trials suggest in aggregate that 10 years of tamoxifen are better than 5 years and that a program of extended adjuvant therapy of tamoxifen for 5 years followed by aromatase inhibitor for 5 years is effective for suitable candidates. The SOFT and E3193 trials do not show a major advantage for use of OFS + tamoxifen compared to tamoxifen alone. The joint SOFT/TEXT analysis and ABCGS12 trials both suggest that outcomes can be excellent with the use of combined endocrine therapy alone in properly selected patients but give conflicting results with regard to potential benefits for OFS + AI compared with OFS + tamoxifen. Further work will be needed to ascertain long-term outcomes, identify factors that predict who will benefit from extended adjuvant endocrine therapy, and assess role of OFS by medical or surgical means. It is clear, however, that endocrine therapy is a critical part of the adjuvant regimen for most premenopausal women with hormone-responsive breast cancer, and a subset of these women with luminal A-type tumors can be safely treated with endocrine therapy alone.

Purpose Triple negative (TN) breast cancers which lack expression of the estrogen (ER), progesterone (PR), and human epidermal growth factor 2 (HER2) receptors convey a poor prognosis due in part to a lack of targeted therapies. Methods To identify viable targets for the treatment of TN disease, we have conducted a gene set enrichment analysis (GSEA) on seven different breast cancer whole genome gene expression cohorts comparing TN vs. ER + HER2 − to identify consistently enriched genes that share a common promoter motif. The seven cohorts were profiled on three different genome expression platforms (Affymetrix, Illumina and RNAseq) consisting in total of 2088 samples with IHC metadata. Results GSEA identified enriched gene expression patterns in TN samples that share common promoter motifs associated with SOX9, E2F1, HIF1A, HMGA1, MYC BACH2, CEBPB, and GCNF/NR6A1. Unexpectedly, NR6A1 an orphan nuclear receptor normally expressed in germ cells of gonads is highly expressed in TN and ER + HER2 − samples making it an ideal drug target. Conclusion With the increasing number of large sample size breast cancer cohorts, an exploratory analysis of genes that are consistently enriched in TN sharing common promoter motifs allows for the identification of possible therapeutic targets with extensive validation in patient derived data sets.

MA17 showed improved outcomes in postmenopausal women given extended letrozole (LET) after completing 5 years of adjuvant tamoxifen.Exploratory subgroup analyses of disease-free survival (DFS), distant DFS (DDFS), overall survival (OS), toxic effects and quality of life (QOL) in MA17 were performed based on menopausal status at breast cancer diagnosis.At diagnosis, 877 women were premenopausal and 4289 were postmenopausal. Extended LET was significantly better than placebo (PLAC) in DFS for premenopausal [hazard ratio (HR) = 0.26, 95% confidence interval (CI) 0.13-0.55; P = 0.0003] and postmenopausal women (HR = 0.67; 95% CI 0.51-0.89; P = 0.006), with greater DFS benefit in those premenopausal (interaction P = 0.03). In adjusted post-unblinding analysis, those who switched from PLAC to LET improved DDFS in premenopausal (HR = 0.15; 95% CI 0.03-0.79; P = 0.02) and postmenopausal women (HR = 0.45; 95% CI 0.22-0.94; P = 0.03).Extended LET after 5 years of tamoxifen was effective in pre- and postmenopausal women at diagnosis, and significantly better in those premenopausal. Women premenopausal at diagnosis should be considered for extended adjuvant therapy with LET if menopausal after completing tamoxifen.

Rationale and Objectives The aim of this prospective study was to investigate using multiparametric and multinuclear magnetic resonance imaging during preoperative systemic therapy for locally advanced breast cancer. Materials and Methods Women with operable stage 2 or 3 breast cancer who received preoperative systemic therapy were studied using dynamic contrast-enhanced magnetic resonance imaging, magnetic resonance spectroscopy, and 23 Na magnetic resonance. Quantitative metrics of choline peak signal-to-noise ratio, total tissue sodium concentration, tumor volumes, and Response Evaluation Criteria in Solid Tumors were determined and compared to final pathologic results using receiver-operating characteristic analysis. Hormonal markers were investigated. Statistical significance was set at P Results Eighteen eligible women were studied. Fifteen responded to therapy, four (22%) with pathologic complete response and 11 (61%) with pathologic partial response. Three patients (17%) had no response. Among estrogen receptor–positive, HER2-positive, and triple-negative phenotypes, observed frequencies of pathologic complete response, pathologic partial response, and no response were 2, 5, and 0; 1, 4, and 0; and 1, 1, and 3, respectively. Responders (pathologic complete response and pathologic partial response) had the largest reductions in choline signal-to-noise ratio (35%, from 7.2 ± 2.3 to 4.6 ± 2; P P = .13) after the first cycle. Total tissue sodium concentration significantly decreased in responders (27%, from 66 ± 18 to 48.4 ± 8 mmol/L; P = .01), while there was little change in nonresponders (51.7 ± 7.6 to 56.5 ± 1.6 mmol/L; P = .50). Lesion volume decreased in responders (40%, from 78 ± 78 to 46 ± 51 mm 3 ; P = .01) and nonresponders (21%, from 100 ± 104 to 79.2 ± 87 mm 3 ; P = .23) after the first cycle. The largest reduction in Response Evaluation Criteria in Solid Tumors occurred after the first treatment in responders (18%, from 24.5 ± 20 to 20.2 ± 18 mm; P = .01), with a slight decrease in tumor diameter noted in nonresponders (17%, from 23 ± 19 to 19.2 ± 19.1 mm; P = .80). Conclusions Multiparametric and multinuclear imaging parameters were significantly reduced after the first cycle of preoperative systemic therapy in responders, specifically, choline signal-to-noise ratio and sodium. These new surrogate radiologic biomarkers maybe able to predict and provide a platform for potential adaptive therapy in patients.

The 21-gene recurrence score assay is prognostic for women with node-negative, oestrogen-receptor-positive breast cancer treated with tamoxifen. A low recurrence score predicts little benefit of chemotherapy. For node-positive breast cancer, we investigated whether the recurrence score was prognostic in women treated with tamoxifen alone and whether it identified those who might not benefit from anthracycline-based chemotherapy, despite higher risks of recurrence.The phase 3 trial SWOG-8814 for postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer showed that chemotherapy with cyclophosphamide, doxorubicin, and fluorouracil (CAF) before tamoxifen (CAF-T) added survival benefit to treatment with tamoxifen alone. Optional tumour banking yielded specimens for determination of recurrence score by RT-PCR. In this retrospective analysis, we assessed the effect of recurrence score on disease-free survival by treatment group (tamoxifen vs CAF-T) using Cox regression, adjusting for number of positive nodes.There were 367 specimens (40% of the 927 patients in the tamoxifen and CAF-T groups) with sufficient RNA for analysis (tamoxifen, n=148; CAF-T, n=219). The recurrence score was prognostic in the tamoxifen-alone group (p=0.006; hazard ratio [HR] 2.64, 95% CI 1.33-5.27, for a 50-point difference in recurrence score). There was no benefit of CAF in patients with a low recurrence score (score18; log-rank p=0.97; HR 1.02, 0.54-1.93), but an improvement in disease-free survival for those with a high recurrence score (scoreor =31; log-rank p=0.033; HR 0.59, 0.35-1.01), after adjustment for number of positive nodes. The recurrence score by treatment interaction was significant in the first 5 years (p=0.029), with no additional prediction beyond 5 years (p=0.58), although the cumulative benefit remained at 10 years. Results were similar for overall survival and breast-cancer-specific survival.The recurrence score is prognostic for tamoxifen-treated patients with positive nodes and predicts significant benefit of CAF in tumours with a high recurrence score. A low recurrence score identifies women who might not benefit from anthracycline-based chemotherapy, despite positive nodes.National Cancer Institute and Genomic Health.

Summary Aims Endocrine therapy is a pivotal treatment for women with hormone-receptor positive breast cancer. In premenopausal women, endocrine therapy primarily consists of tamoxifen and ovarian suppressive strategies. Younger women experience improvements in the risks of relapse or death from breast cancer with the use of chemotherapy as well, with part of this benefit explained by resultant premature amenorrhea. Unfortunately despite a centuries worth of clinical trials, the most efficacious combination of hormonal therapies and chemotherapy has yet to be determined. This paper serves as a comprehensive review of the substantial data in the adjuvant treatment of premenopausal, hormone receptor-positive women with breast cancer. Methods and Results PubMed and American Society of Clinical Oncology (ASCO) Proceedings searches from 1896 to present were performed. All of the trials examining the role of ovarian suppression and tamoxifen with and without chemotherapy in premenopausal women were included. The current data suggests that endocrine therapy can be an important alternative to chemotherapy in select patient populations, and improvements in outcome are also seen with the combination of hormonal and chemotherapy strategies in other populations. A majority of the trials examined did not use what is considered to be current standards of care regarding chemotherapy regimens and durations of adjuvant hormonal therapy. Many unanswered questions remain particularly regarding the combined use of ovarian suppression and tamoxifen in women who are also receiving chemotherapy. Conclusion There is a persistent need to define optimal endocrine therapy in premenopasusal women with hormone-receptor positive breast cancer. Contemporaneous trials, such as the SOFT trial will provide direction, and additional biomarker and pharmacogenomic data will further supplement individualized patient decision making.

Gene expression profiling is enabling scientists to understand the heterogeneous nature of breast cancer on a genomic level. Several gene expression profiles for breast cancers have emerged in the initial studies and appear to be generally concordant in their ability to predict poor outcome. Of these profiles, the Oncotype Dx and Mammaprint assays are the best validated and are commercially available. Their role in clinical practice is being refined through ongoing clinical trials. Other efforts are directed at determining host factors that might help identify prognosis as well as response and toxicity of therapy. It is expected that availability of these types of analyses will only increase in the future. It will be imperative that such assays be well validated and have implications for how to modify care for the individual patient.

MA.17 evaluated letrozole or placebo after 5 years of tamoxifen and showed significant improvement in disease-free survival (DFS) for letrozole [hazard ratio (HR) 0.57, P = 0.00008]. The trial was unblinded and placebo patients were offered letrozole.An intent-to-treat analysis of all outcomes, before and after unblinding, on the basis of the original randomization was carried out.In all, 5187 patients were randomly allocated to the study at baseline and, at unblinding, 1579 (66%) of 2383 placebo patients accepted letrozole. At median follow-up of 64 months (range 16-95), 399 recurrences or contralateral breast cancers (CLBCs) (164 letrozole and 235 placebo) occurred. Four-year DFS was 94.3% (letrozole) and 91.4% (placebo) [HR 0.68, 95% confidence interval (CI) 0.55-0.83, P = 0.0001] and showed superiority for letrozole in both node-positive and -negative patients. Corresponding 4-year distant DFS was 96.3% and 94.9% (HR 0.80, 95% CI 0.62-1.03, P = 0.082). Four-year overall survival was 95.1% for both groups. The annual rate of CLBC was 0.28% for letrozole and 0.46% for placebo patients (HR 0.61, 95% CI 0.39-0.97, P = 0.033).Patients originally randomly assigned to receive letrozole within 3 months of stopping tamoxifen did better than placebo patients in DFS and CLBC, despite 66% of placebo patients taking letrozole after unblinding.

Endocrine therapy is a required element of the management of premenopausal women with early-stage steroid hormone receptor-positive breast cancer. There is uncertainty about how best to implement that therapy using the strategies of tamoxifen and estrogen deprivation as well as how to integrate these approaches with chemotherapy. Other research focuses on identification of improved markers for endocrine response or resistance and on the special side effects of endocrine therapy in young women.

A series of novel chalcones and bis-chalcones containing boronic acid moieties has been synthesized and evaluated for antitumor activity against the human breast cancer MDA-MB-231 (estrogen receptor-negative) and MCF7 (estrogen receptor-positive) cell lines and against two normal breast epithelial cell lines, MCF-10A and MCF-12A. These molecules inhibited the growth of the human breast cancer cell lines at low micromolar to nanomolar concentrations, with five of them (1-4, 9) showing preferential inhibition of the human breast cancer cell lines. Furthermore, bis-chalcone 8 exhibited a more potent inhibition of colon cancer cells expressing wild-type p53 than of an isogenic cell line that was p53-null.

Background The purpose of this study was to evaluate the prognostic and predictive utility of measuring plasma levels of matrix metalloproteinase (MMP)—7 and MMP-9 in patients with metastatic breast cancer (MBC) treated with the oral MMP inhibitor (MMPI) marimastat or a placebo. Patients and Methods We measured plasma levels of MMP-7 and MMP-9 using an enzyme-linked immunoassay method in 140 evaluable patients with MBC enrolled on a multicenter clinical trial that compared the MMPI marimastat with placebo. Specimens were collected after completion of first-line chemotherapy in patients who had responding or stable disease and 3, 6, and 12 months after initiation of marimastat (10 mg orally twice daily) or placebo. Results Baseline plasma MMP-7 and MMP-9 levels did not correlate with each other or with progression-free or overall survival. In addition, serial evaluation of plasma MMP-7 and MMP-9 levels revealed no significant changes over time in the marimastat or placebo groups or any correlation with trough plasma marimastat level. Conclusion We conclude that measurement of plasma MMP-7 or MMP-9 levels, as performed in our trial, was not a useful prognostic or predictive factor in patients with MBC or in patients treated with an MMPI.

The induction of polyamine catabolism and its production of H2O2 have been implicated in the response to specific antitumor polyamine analogues. The original hypothesis was that analogue induction of the rate-limiting spermidine/spermine N1-acetyltransferase (SSAT) provided substrate for the peroxisomal acetylpolyamine oxidase (PAO), resulting in a decrease in polyamine pools through catabolism, oxidation, and excretion of acetylated polyamines and the production of toxic aldehydes and H2O2. However, the recent discovery of the inducible spermine oxidase SMO(PAOh1) suggested the possibility that the original hypothesis may be incomplete. To examine the role of the catabolic enzymes in the response of breast cancer cells to the polyamine analogue N1,N1-bis(ethyl)norspermine (BENSpm), a stable knockdown small interfering RNA strategy was used. BENSpm differentially induced SSAT and SMO(PAOh1) mRNA and activity in several breast cancer cell lines, whereas no N1-acetylpolyamine oxidase PAO mRNA or activity was detected. BENSpm treatment inhibited cell growth, decreased intracellular polyamine levels, and decreased ornithine decarboxylase activity in all cell lines examined. The stable knockdown of either SSAT or SMO(PAOh1) reduced the sensitivity of MDA-MB-231 cells to BENSpm, whereas double knockdown MDA-MB-231 cells were almost entirely resistant to the growth inhibitory effects of the analogue. Furthermore, the H2O2 produced through BENSpm-induced polyamine catabolism was found to be derived exclusively from SMO(PAOh1) activity and not through PAO activity on acetylated polyamines. These data suggested that SSAT and SMO(PAOh1) activities are the major mediators of the cellular response of breast tumor cells to BENSpm and that PAO plays little or no role in this response.

We report that DNA methyltransferase 1 (DNMT1) expression is dysregulated in breast cancer. The elevated protein levels are not a result of increased mRNA levels, but rather an increase in protein half-life. We found that DNMT1 protein levels were elevated in breast cancer tissues and in MCF-7 breast cancer cells relative to normal human mammary epithelial cells (HMECs) without a concomitant increase in DNMT1 mRNA or proliferative fraction. Although DNMT1 mRNA levels were properly S-phase-regulated in both cell types, DNMT1 protein levels did not follow S-phase fraction in MCF-7 cells. Rather, an increase in DNMT1 protein stability was found for MCF-7 cells relative to HMECs, and a destruction domain was mapped to the N-terminal 120 amino acids of DNMT1, which was required for its proper ubiquitination and degradation in HMECs. Furthermore, overexpression of DNMT1 with this deleted destruction domain in HMECs resulted in significantly increased genomic 5-methylcytosine levels relative to overexpression of the full-length protein. The regulation of DNMT1 destruction via this domain may be dysfunctional in cancer cells leading to subsequent cytosine hypermethylation in the genome.

Background GM-CSF-secreting, allogeneic cell-based cancer vaccines have shown promise for the treatment of a variety of solid tumors. We have now applied this approach to breast cancer. The aim of these studies was to optimize expansion parameters, qualify the manufacturing process, and establish expected outcomes for cGMP-compliant manufacturing of two GM-CSF-secreting breast tumor cell lines. Methods The variables affecting the efficiency of expanding and formulating two allogeneic GM-CSF-secreting cell lines, 2T47D-Vand 3SKBR3-7, were systematically evaluated. Production criteria investigated included alternative cell culture vessels (flasks vs. cell factories), centrifugation time and speed variables for large volume cell concentration, cell seeding density, the minimal concentration ofFBS required for maximal cell expansion, and the dose and timing of irradiation in relation to cryopreservation. Results These studies demonstrate that, in comparison with standard 150-cm tissue culture flasks, Nunc 10-Stack Cell Factories are a more efficient and practical cell culture vessel for vaccine cell line manufacture. Centrifugation optimization studies using the COBF ® 2991™ Cell Processor established that a speed of 2000 r.p.m. (450g) for 2min reliably concentrated the cells while maintaining acceptable viability and bioactivity. Radiation studies established that lethal irradiation prior to cryopreservation does not compromise the quality of the product, as measured by post-thaw cell viability and GM-CSF cell line-specific secretion levels. Finally, studies aimed at optimizing the production of one vaccine cell line, 3SKBR3-7, demonstrated that seeding the cells at a higher density and maintaining them in half the initial concentration of FBS maximized the yield of bioactive cells, resulting in significant cost savings. Discussion A manufacturing process that simultaneously maximizes cell yield, minimizes cell manipulation and maintains vaccine cell potency is critical for producing cell-based cancer vaccines in an academic setting. These studies define a feasible, reproducible and cost-effective methodology for production of a GM-CSF-secreting breast cancer vaccine that is cGMP compliant.

For over a decade, the selective estrogen receptor modulator, tamoxifen, has been the primary agent for adjuvant endocrine therapy for steroid receptor-positive breast cancer. New data over the last 2 years now suggest that its primacy may be challenged by strategies that lower circulating and/or intratumoral estrogens. Recent trials support the use of ovarian suppression approaches with or without tamoxifen in place of chemotherapy in premenopausal women. A large randomized trial has also established the short-term efficacy and safety of the aromatase inhibitor, anastrozole, in postmenopausal women. How and when to integrate these new approaches into standard practice are topics of debate. Ongoing research is focused on choice of endocrine approach, duration and sequencing of endocrine treatment, identification of better predictive markers for hormone response, and assessment of long-term risks and benefits.

Adenocarcinoma of the breast is the most common cancer of American women. Increased incidence and reduced mortality have generated a population of more than 2 million breast cancer survivors who require medical follow-up. In addition to therapy-related complications, these women are at risk for locoregional recurrence, distant relapse, and the development of second primary breast tumors. Medical surveillance after primary breast cancer treatment has historically included regular patient history and physical examinations, complete blood cell counts, comprehensive blood chemistries, tumor markers, mammography, chest x-rays, and sometimes computed tomography (CT) and nuclear medicine bone scans. The use of such intensive surveillance was based on the presumption that detecting disease recurrence at its earliest stage would offer the chance of cure, improved survival, or at least improved quality of life. Here we review the evidence that such intensive surveillance is not cost-effective, and in fact has no significant impact on the overall survival or quality of life of women diagnosed with early-stage breast cancer. Finally, we present an evidence-based approach to breast cancer surveillance after therapy that is consistent with several clinical practice guidelines, maximizing outcome and minimizing cost.

The use of systemic adjuvant therapy in women with early-stage breast cancer has been demonstrated to have a profound impact on survival. The role of paclitaxel and docetaxel in the adjuvant setting has attracted a great deal of attention. Both of these agents are highly active in patients with advanced breast cancer. In addition, they can be utilized in combination with anthracyclines, which have been shown to provide a slightly better outcome in patients with early-stage breast cancer compared to non—anthracycline-containing regimens. Randomized trials have demonstrated a potential role for paclitaxel in adjuvant chemotherapy. In the Cancer and Leukemia Group B 9344 trial, which explored the use of doxorubicin and cyclophosphamide with or without paclitaxel, the initial analysis demonstrated a 22% reduction in the relative risk of relapse and a 26% reduction in the relative risk of death in the paclitaxel group. However, a clear role for the use of paclitaxel in adjuvant therapy remains to be defined. The Breast Cancer International Research Group trial 001 compared the combination of docetaxel/doxorubicin/cyclophosphamide to 5-fluorouracil/doxorubicin/ cyclophosphamide. This trial demonstrated a promising reduction in the relative risk of recurrence of 32% for the docetaxel/doxorubicin/cyclophosphamide group. Ongoing trials will help to further define the role of taxanes in the adjuvant setting for patients with operable breast cancer.

Triple negative breast cancer (TNBC) comprises ~20% of all breast cancers and has a decreased 5-year survival rate compared to other breast cancer subtypes. Patients with TNBC are difficult to treat due to an absence of targeted therapies, contributing to poor clinical outcomes. This study investigated the antineoplastic effects of an electrophilic fatty acid nitroalkene derivative, 10-nitro-octadec-9-enoic acid (nitro-oleic acid, NO2-OA), in TNBC cells. NO2-OA reduced TNBC cell growth and viability in vitro, and in vivo tumor growth of MDA-MB-231 xenografts in nude mice. Interestingly, NO2-OA displayed a less cytotoxic effect on non-cancerous breast cells, attributed to MRP1-mediated efflux of NO2-OA GSH conjugates. Boyden chamber assays demonstrated that NO2-OA significantly attenuated tumor necrosis factor α (TNFα)-induced migration and invasion of TNBC cells. In TNBC cells, NO2-OA inhibited TNFα-induced nuclear factor kappa B (NF-κB) transcriptional activity and thus suppressed downstream NF-κB target gene expression, including the metastasis-related proteins, intercellular adhesion molecule-1 (ICAM-1) and urokinase-type plasminogen activator (uPA). The mechanism of NF-κB signaling inhibition by NO2-OA was multifarious as NO2-OA impeded IKKβ phosphorylation and thus IκBα degradation. NO2-OA also alkylated the NF-κB RelA protein in TNBC cells and promoted its polyubiquitination and proteasomal degradation. Constitutive activation of the NF-κB pathway plays an important role in promoting TNBC progression and metastasis, thus these observations suggest that NO2-OA and related fatty acid electrophiles may have therapeutic potential as agents displaying selectivity for treating TNBC.

SUMMARY The anthracyclines (doxorubicin and epirubicin) and taxanes (paclitaxel and docetaxel) are among the most active agents for the treatment of advanced breast cancer. The efficacy and safety of anthracycline–taxane combinations have been established in this setting. As a consequence, their use in early-stage breast cancer is an area of active investigation. Two general strategies have been pursued – combinations of taxane and anthracycline and sequential use of anthracycline followed by taxane or the reverse. This review summarizes our current knowledge about the adjuvant use of doxorubicin and paclitaxel or docetaxel for breast cancer, focusing on randomized clinical trials of the US cooperative groups as examples of the development process.

Epidermal growth factor (EGF), a hormone that stimulates proliferation of many cell types, induces apoptosis in some cell lines that overexpress the EGF receptor. To evaluate the mechanism of EGF-induced apoptosis, MDA-MB-468 breast cancer cells were examined by microscopy, flow cytometry, immunoblotting, enzyme assays, and affinity labeling after treatment with EGF, paclitaxel, or 5-fluoro-2′-deoxyuridine (5FUdR). Apoptosis induced by all three agents was accompanied by activation of caspases-3, -6, and -7, as indicated by disappearance of the corresponding zymogens from immunoblots, cleavage of substrate polypeptides in situ, and detection of active forms of these caspases in cytosol and nuclei using fluorogenic assays and affinity labeling. Further analysis indicated involvement of the cytochrome c/Apaf-1/caspase-9 pathway of caspase activation, but not the Fas/Fas ligand pathway. Interestingly, caspase activation was consistently lower after EGF treatment than after paclitaxel or 5FUdR treatment. Additional experiments revealed that the majority of cells detaching from the substratum after EGF (but not paclitaxel or 5FUdR) were morphologically normal and retained the capacity to readhere, suggesting that EGF-induced apoptosis involves cell detachment followed by anoikis. These observations not only indicate that EGF- and chemotherapy-induced apoptosis in this cell line involve the same downstream pathways but also suggest that detachment-induced apoptosis is responsible for the paradoxical antiproliferative effects of EGF.

This article focuses on the major hormones and growth factors for which a critical role in normal mammary growth has been clearly defined. Certainly other hormonal systems and growth factors could also affect breast cancer initiation and progression, but their exact contribution to normal and/or malignant breast cell growth is poorly delineated. Examples of such factors include somatostatin, mammostatin, mammary-derived growth inhibitor (MDGI), mammary-derived growth factor-1 (MDGF-1), inhibins, activins, androgens, glucocorticoids, vitamin D, thyroid hormones, ecosinoids, and oxytocin. Clearly, the hormonal regulation of breast cancer cell growth and survival is multifaceted and very complex. In particular, the effects of estrogens and anti-estrogens on breast cells may depend on their interaction with a wide variety of other pathways. In addition, these interactions may vary among individual breast tumors depending on other genetic changes in the tumor cells that have not been discussed here, such as oncogene activation and loss of tumor suppressors. A more detailed understanding of how cells circumvent a dependency on these pathways is greatly needed in order to identify new biological targets and to design novel therapies for breast cancers that are resistant to anti-estrogen therapy. Such agents could be used alone or in combination with anti-estrogens to improve response to a second course of hormonal therapy.

The cytosine analog 5-aza-2'-deoxycytidine is a potent inhibitor of DNA methyltransferase. Its cytotoxicity has been attributed to several possible mechanisms including reexpression of growth suppressor genes and formation of covalent adducts between DNA methyltransferase and 5-aza-2'-deoxycytidine-substituted DNA which may lead to steric inhibition of DNA function. In this study, we use a panel of human breast cancer cell lines as a model system to examine the relative contribution of two mechanisms, gene reactivation and adduct formation. Estrogen receptor-negative cells, which have a hypermethylated estrogen receptor gene promoter, are more sensitive than estrogen receptor-positive cells and underwent apoptosis in response to 5-aza-2'-deoxycytidine. For the first time, we show that reactivation of a gene silenced by methylation, estrogen receptor, plays a major role in this toxicity in one estrogen receptor-negative cell line as treatment of the cells with anti-estrogen-blocked cell death. However, drug sensitivity of other tumor cell lines correlated best with increased levels of DNA methyltransferase activity and formation DNA.DNA methyltransferase adducts as analyzed in situ. Therefore, both reexpression of genes like estrogen receptor and formation of covalent enzyme. DNA adducts can play a role in 5-aza-2'-deoxycytidine toxicity in cancer cells.

Using murine myeloid factor-dependent FDC-P1/ER cells, we demonstrate that the hematopoietic growth factors interleukin-3 and erythropoietin and bryostatin-1, a macrocyclic lactone natural product and potent activator of protein kinase C (PKC), suppress apoptosis and induce the rapid serine phosphorylation of Bc12 alpha. Expression of recombinant wild type Bc12 alpha in NFS/N1.H-7 cells confirms that murine Bc12 alpha is phosphorylated following PKC activation. The PKC inhibitors H-7 and staurosporine, but not the protein kinase A inhibitor HA1004, block not only interleukin-3- and bryostatin-1-induced hyperphosphorylation of Bc12 alpha but also their anti-apoptotic effect on growth factor-dependent cells, suggesting a role for activated PKC in both processes. A potential direct role for a classic isoform of PKC is indicated by the Ca(2+)-dependent nature of phosphorylation of Bc12 alpha mediated by purified PKC in vitro. Comparative phosphopeptide maps confirm that Bc12 alpha phosphorylation occurs on identical serine site(s) whether phosphorylation occurs in cells following agonist treatment or directly by PKC in vitro. These findings strongly support a role for activated PKC in growth factor-induced Bc12 alpha phosphorylation as well as suppression of apoptosis.

SummaryMechanisms for breast cancer recurrence and metastases are poorly understood. New evidence from a transgenic mouse mammary tumor model suggests that the transcriptional repressor, Snail, may play a role in recurrence by downregulating E-cadherin and inducing an epithelial-to-mesenchymal transition. Preliminary information from expression microarray data sets from primary human breast cancers suggests that high levels of Snail are correlated with poor clinical outcome for women with early breast cancer. The identification of a molecular pathway involved in mammary tumor recurrence in a mouse model offers both opportunity and challenge to confirm, extend, and exploit these findings in the clinic.

The effect of aflatoxin B1 on the binding capacity of rat liver cytoplasmic glucocorticoid receptors and the nuclear binding of the activated receptor complex was investigated. No alterations in the kinetics of [3H]desamethasone-cytosol receptor complex formation were noted 2 h after treatment with 1 mg/kg aflatoxin B1. However, a 33% decrease in the concentration of nuclear acceptor sites and a 24% decrease in the glucocorticoid receptor-nuclear binding equilibrium constant of dissociation was observed. This response was near maximal at 2 h and persisted for at least 26 h. Inhibition of nuclear binding capacity was directly related to aflatoxin B1 dose, with a correlation coefficient of 0.99. Actinomycin D treatment (0.1 mg/kg) resulted in a slight reduction (16%) in the concentration of nuclear acceptor sites but had no effect on the nuclear binding dissociation constant. Administration of [3H]dexamethasone to alfatoxin B1 -treated rats produced a similar pattern of glucocorticoid binding distribution in vivo to that observed in vitro. No differences in [3H]dexamethasone-cytoplasmic receptor binding between control and alfatoxin B1 -treated rats were found, whereas nuclear [3H]dexanthasone binding was reduced 34% by alfatoxin B1 -treatment.

Previous work from our laboratory has demonstrated that human breast cancer (BC) cells in culture can be stimulated by physiologic concentrations of estrogen. In an effort to further understand this process, we have examined the biochemical and biological properties of proteins secreted by human BC cells in vitro. We have developed a defined medium system which simultaneously allows the collection of factors secreted by the BC cells, facilitates their purification and allows for an unequivocal assay of their effect on other BC cells. By both biochemical and radioimmunoassay procedures, MCF-7 cells secrete large quantities of IGF-I-like activity. The cells contain receptors for IGF-I and are stimulated by physiologic concentrations of IGF-I. Multiple additional peaks of growth stimulatory activity can be obtained by partial purification of conditioned media from human BC cells by sequential dialysis, acid extraction and Biogel P60 chromatography. These peaks are induced up to 200-fold by physiologic concentrations of estrogen. Several of these peaks cross-react in a radioreceptor assay with EGF and are thus candidates for transforming growth factors. Monoclonal antibodies (MCA) have been prepared which react with secreted proteins from the MCF-7 cells. One of these MCAs binds to material from MCF-7 and ZR-75-1 hormone-dependent BC cells only when these two lines are treated with estrogen but reacts with conditioned medium from several other hormone-independent cell lines in the absence of estrogen stimulation. This MCA is currently undergoing further characterization and evaluation of its biological potency. We conclude that with estrogen stimulation, hormone-dependent human BC cells secrete peptides which when partially purified can replace estrogen as a mitogen. Their role as autocrine or paracrine growth factors and their effects on surrounding nonneoplastic stroma may suggest a means of interfering with tumor proliferation.