Abstract P1-10-04: AGR2, an estrogen response gene associated with tamoxifen resistance, is modulated by acolbifene in premenopausal women at high risk for development of breast cancer

Anterior Gradient 2 is an estrogen early response gene (AGR2) and protein (AGR-2). High expression is associated with endoplasmic reticulum stress and endocrine therapy resistance. Developmentally, AGR2 is associated with estrogen-mediated epithelial proliferation and lobuloalveolar development. In the adult, AGR2 is upregulated by inflammatory and metabolic stress signaling from NFKB, HSP90, IGFR-1, and FOXA1, in addition to estrogen bound to its receptor. The Selective Estrogen Receptor Modulator (SERM) Full dose tamoxifen has been reported to upregulate AGR2 in breast cancer but Selective Estrogen Receptor Down Regulators (SERDs) and aromatase inhibitors do not. AGR-2 is also a secreted protein, with increased tumor levels associated with metastases and decreased disease-free survival in tamoxifen-treated patients. We assessed AGR2 expression in reserved benign breast tissue from baseline and off-study specimens acquired by random periareolar fine needle aspiration (RPFNA) of premenopausal women at high risk for development of breast cancer who had participated in an early phase prevention trial of the SERM acolbifene (20 mg daily for 6 months). This pilot had demonstrated reduced Ki-67 and down-regulation of several estrogen response genes (Fabian et al. Ca Prev Res 2015). Methods Total RNA was extracted from aliquots of frozen benign breast tissue using TRIzol LS (Life Technologies) and purified using RNeasy MinElute Cleanup Kit (Qiagen). RNA was amplified using MessageAmpII aRNA amplification kit (Life Technologies) and reverse transcribed to cDNA using SMARTScribe Reverse Transcriptase (Takara Bio USA, Inc.) and random nonamer primers. Real-time quantitative PCR (qPCR) was performed using hydrolysis probes with baseline and postintervention specimens assessed together. PCR reactions were run on an Applied Biosystems Prism 7000 Sequence Detection System. The cycle threshold mean value for each transcript (from duplicate assays per specimen) was normalized using three reference transcripts, plus two epithelial cell transcripts. Relative levels of each transcript were calculated using the ΔΔCt method. The ratio (postintervention: baseline) of final values indicated upregulation (value > 1) or downregulation (value < 1). Results There were 17 available paired specimens for analysis for AGR2 gene expression which was downregulated in 13 with nine by more than a 50% reduction; for the four cases of up-regulation, three were increased by more than two-fold (p=0.076, Wilcoxon signed ranks test). Several estrogen response genes (TFF1, PGR, and the ratio of ESR1:ESR2) exhibited significant down-regulation (p≤0.007). Further, there was no evidence of linear correlation (p>0.28; Spearman’s rho) between change in AGR2 and any of these other estrogen response genes. Lastly, when an Estrogen Response Gene Index (ERGI) was constructed using the average log2(fold change) for TFF1, PGR, and the ratio of ESR1:ESR2, down regulation was observed in 16 of the 17 paired specimens with only one increase. ERGI and AGR2 change indicate favorable modulation by acolbifene and appear to provide independent information. Conclusions These results suggest that change in expression of benign breast AGR2 might be a useful addition to change in expression of other classic estrogen response genes in evaluating the potential of novel SERMs such as acolbifene compared to standard SERMs like tamoxifen in early phase prevention trials.

Citation Format: Carol J. Fabian, Teresa A. Phillips, Bruce F. Kimler. AGR2, an estrogen response gene associated with tamoxifen resistance, is modulated by acolbifene in premenopausal women at high risk for development of breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-10-04.

Abstract P2-11-17: Feasibility of microbiome analysis from random periareolar fine needle aspiration in premenopausal women at increased risk for breast cancer

Background: Nearly 10% of breast cancers (BC) are diagnosed in premenopausal woman under age 45 and of childbearing potential. Women considering future childbearing are typically excluded from BC prevention trials and are ineligible for standard of care chemoprevention. More biomarkers are needed to support BC prevention trials in this young cohort. Women of childbearing potential are encouraged to supplement diet with minimum of 300mg of EPA + DHA omega-3 fatty acids (FA) per day. EPA and DHA are thought to have a favorable effect on the gut microbiome implicated in cancer development. Few studies have characterized the breast microbiome by core biopsy or surgical sample but to our knowledge no studies have explored the feasibility of breast microbiome collection using the less invasive technique Random Periareolar Fine Needle Aspiration (RPFNA). In a pilot study, we demonstrated feasibility of recruiting premenopausal women considering future pregnancy to a BC prevention trial with a 6-month intervention of omega-3 FA supplementation (19-A-1921-SABCS). RPFNA was used to collect breast tissue for biomarker analysis, which is a mildly invasive technique used for repeated sample collection in BC prevention trials. Objectives: 1) To determine the feasibility of characterizing breast microbiome from specimens collected by RPFNA in premenopausal woman at high risk for BC, 2) To identify changes in the breast and stool microbiome with omega-3 FA supplementation in this population. Methods: Ten women between the ages of 21 and 40 who were considering future pregnancy and at high risk for BC were enrolled to a pilot study and took Omega-3-Acid Ethyl Ester (total of 750mg DHA and 930mg EPA) daily for 6 months. Tissue collection with RPFNA of breast as well as blood, urine and stool were completed at baseline and off-study visit. RPFNA samples from the first 2 passes at each site of breast (4 sites total) were collected for microbiome and placed in a 2mL tube with 0.5 – 1cc of PBS and flash frozen and stored at -80C. DNA was isolated from RPFNA samples using QIAamp DNA Mini Kit (51304). Microbiome profiling analysis was performed by Veracet using 16S V4 rRNA gene sequencing on the Illumina MiSeq platform. Wilcoxon signed rank test was used to compare paired samples. Results: Of the 10 women enrolled, median age was 33 years (range 22-37). 90% (9 of 10) returned for off-study visit. Of the 9 women who completed the off-study visit, 2 elected to not undergo off-study RPFNA. There were 16 total stool samples and 17 total RPFNA samples for microbiome evaluation. There were 6 paired (baseline and off-study) stool and 7 paired RPFNA samples. Mean DNA concentration from RPFNA samples was 10.36ng/µl (range 0.62 – 74.10). From all samples, 52.1% of operational taxonomic units (OTUs) were classified at the genus level. Breast samples were sequenced to a depth of mean 27,767 reads (range 5,745 – 125,445) and stool to a depth of mean 119,296 reads (range 72,979 – 188,867). The alpha diversity metric of OTU richness was 1069 (breast) and 438 (stool). Shannon diversity was 4.51 (breast) and 3.89 (stool). Mean OTU richness for baseline and off-study RPFNA samples were 1098 and 1028 respectively (V = 25, p value = 0.076). Mean OTU richness for baseline and off-study stool samples were 440 and 437 respectively (V = 15, p value = 0.40). Conclusion: We demonstrated feasibility of analyzing breast microbiome from an RPFNA specimen. Additional investigation with modifications to technique and/or sample population is. needed to achieve adequate sequencing depth for characterization of breast microbiome. Lower depth of sequencing in breast samples is thought to reflect differences in microbial DNA quantity. We were unable to assess change in microbiome composition in breast or stool samples with omega-3 fatty acid supplementation due to small sample size.

Citation Format: Lauren E Nye, Jennifer R Klemp, Kandy R Powers, Anne P O'Dea, Amy L Kreutzjans, Trina Metheny, Teresa A Phillips, Susan E Carlson, Bruce F Kimler, Carol J Fabian. Feasibility of microbiome analysis from random periareolar fine needle aspiration in premenopausal women at increased risk for breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-11-17.

Rapid Escalation of High-Volume Exercise during Caloric Restriction; Change in Visceral Adipose Tissue and Adipocytokines in Obese Sedentary Breast Cancer Survivors

Simple Summary

Aerobic exercise reduces risk for developing breast cancer or for breast cancer recurrence. In obese women exercise can significantly augment the effects of caloric restriction on visceral fat, reducing metabolic abnormalities and cancer. Women who are older, obese, and sedentary, especially those who have been treated for breast cancer, find it difficult to initiate and achieve the minimum or optimum levels of exercise. In a two-part pilot we found that by providing older, obese, sedentary breast cancer survivors 12 weeks of twice weekly personal training sessions, they could safely increase exercise to ≥200 min/week by 9 weeks during caloric restriction. At 24 weeks, high levels of exercise were still observed with continued behavioral support and study-provided exercise facility. Substantial improvement in visceral fat and breast cancer risk biomarkers were observed with this affordable intervention that is readily exportable to the community.

Abstract

Aerobic exercise reduces risk for breast cancer and recurrence and promotes visceral adipose tissue (VAT) loss in obesity. However, few breast cancer survivors achieve recommended levels of moderate to vigorous physical activity (MVPA) without supervision. In a two-cohort study, feasibility of 12 weeks of partially supervised exercise was started concomitantly with caloric restriction and effects on body composition and systemic risk biomarkers were explored. In total, 22 obese postmenopausal sedentary women (including 18 breast cancer survivors) with median age of 60 and BMI of 37 kg/m² were enrolled. Using personal trainers twice weekly at area YMCAs, MVPA was escalated to ≥200 min/week over 9 weeks. For cohort 2, maintenance of effect was assessed when study provided trainer services were stopped but monitoring, group counseling sessions, and access to the exercise facility were continued. Median post-escalation MVPA was 219 min/week with median 12-week mass and VAT loss of 8 and 19%. MVPA was associated with VAT loss which was associated with improved adiponectin:leptin ratio. In total, 9/11 of cohort-2 women continued the behavioral intervention for another 12 weeks without trainers. High MVPA continued with median 24-week mass and VAT loss of 12 and 29%. This intervention should be further studied in obese sedentary women.

Change in Blood and Benign Breast Biomarkers in Women Undergoing a Weight-Loss Intervention Randomized to High-Dose ω-3 Fatty Acids versus Placebo

The inflammation-resolving and insulin-sensitizing properties of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids have potential to augment effects of weight loss on breast cancer risk. In a feasibility study, 46 peri/postmenopausal women at increased risk for breast cancer with a body mass index (BMI) of 28 kg/m² or greater were randomized to 3.25 g/day combined EPA and DHA (ω-3-FA) or placebo concomitantly with initiation of a weight-loss intervention. Forty-five women started the intervention. Study discontinuation for women randomized to ω-3-FA and initiating the weight-loss intervention was 9% at 6 months and thus satisfied our main endpoint, which was feasibility. Between baseline and 6 months significant change (P < 0.05) was observed in 12 of 25 serum metabolic markers associated with breast cancer risk for women randomized to ω-3-FA, but only four for those randomized to placebo. Weight loss (median of 10% for trial initiators and 12% for the 42 completing 6 months) had a significant impact on biomarker modulation. Median loss was similar for placebo (-11%) and ω-3-FA (-13%). No significant change between ω-3-FA and placebo was observed for individual biomarkers, likely due to sample size and effect of weight loss. Women randomized to ω-3-FA exhibiting more than 10% weight loss at 6 months showed greatest biomarker improvement including 6- and 12-month serum adiponectin, insulin, omentin, and C-reactive protein (CRP), and 12-month tissue adiponectin. Given the importance of a favorable adipokine profile in countering the prooncogenic effects of obesity, further evaluation of high-dose ω-3-FA during a weight-loss intervention in obese high-risk women should be considered. PREVENTION RELEVANCE: This study examines biomarkers of response that may be modulated by omega-3 fatty acids when combined with a weight-loss intervention. While focused on obese, postmenopausal women at high risk for development of breast cancer, the findings are applicable to other cancers studied in clinical prevention trials.

Abstract PD11-02: Randomized trial of 12 months of omega-3 fatty acids vs placebo during a weight loss intervention in post-menopausal women at increased risk for breast cancer

Objectives: The primary objective was to determine tolerability of ω-3 fatty acids (2150 mg of eicosapentaenoic acid (EPA) and 1050 docosahexaenoic acid (DHA) ethyl esters) vs placebo in women in undergoing a behavioral weight loss intervention (6 months loss and 6 months maintenance). Secondary objectives were to explore potential differences in modulation of blood and benign breast tissue risk biomarkers, satiety and quality of life indices, and weight loss. Results: 46 peri and postmenopausal women were randomized and 42 completed the 6 months of the weight loss intervention and were biomarker evaluable (22 placebo and 20 ω-3 FA). Median baseline BMI in the 42 evaluable women was 31 kg/m2 with a median 6-month relative weight loss of 11% and relative fat mass loss of 20% (DXA). Median 12-month relative mass loss was 10% in the 35 women completing 12 months of the intervention. ω-3 fatty acids increased the ratio of (EPA+DHA): arachidonic acid 2.6-fold (median, range 1.8 - 3.8) vs no change for placebo. There was no difference by randomization group in relative weight or fat mass loss at 6 or 12 months, grade 2 and 3 adverse events, early discontinuation, satiety or other quality of life measures. More serum biomarkers exhibited significant within-group improvement at 6 and 12 months for evaluable women randomized to ω-3 FA than to placebo. At 6 months, significant change (P&lt;0.05) was observed for adiponectin, leptin, adiponectin:leptin ratio, insulin, lipocalin-2, resistin, PAI-1, HGF, CRP, SHBG, and bioavailable testosterone in women randomized to ω-3 FA but only for leptin, adiponectin: leptin ratio and SHBG in those randomized to placebo. At 6 months, the 21 women who lost &gt;10% weight (median 15%) showed significant within-group improvement in adiponectin, leptin, adiponectin:leptin ratio, insulin, lipocalin-2, resistin, PAI-1, HGF, CRP, SHBG, bioavailable estradiol and bioavailable testosterone. For women with &lt;10% weight loss (median 6%) there was significant within-group improvement only for leptin, the adiponectin: leptin ratio, and SHBG. Little change was observed for inflammatory cytokines IL-6, TNF-alpha, MCP-1 or FABP4, or FGF-21 with ω-3 FA or &gt;10% weight loss. Given the dramatic effect of weight loss on biomarkers, we examined within-group and between-group change from baseline to 6 and 12 months for the four subgroups (10-11 women in each) defined by ω-3 FA or placebo and &lt; or &gt; 10% weight loss at 6 months. The subgroup of &gt;10% loss + ω-3 FA had the greatest within-group change in the proportion of significantly modulated biomarkers at 6 months. &gt;10% loss + ω-3 FA was the only subgroup with a significant within-group increase in adiponectin at both 6 and 12 months and achievement of a beneficial ratio of adiponectin (ug/ml) to leptin (ng/ml) of &gt; 1.0 in 100% of participants. There was a significant between-group effect for adiponectin for &gt;10% loss + ω-3 FA vs each of the other groups. Biomarkers were assessed in tissue acquired by random periareolar fine needle aspiration (RPFNA). There were no significant differences in change in cytomorphology or Ki-67 between women randomized to ω-3 FA or placebo but there were significant within-group increases in benign breast adiponectin (pg/ug protein) at 12 months (p=0.014) for women randomized to ω-3 FA. Conclusions: EPA + DHA ethyl esters (3150 mg/day), added to a behavioral weight loss program in overweight women at increased risk for breast cancer, is well-tolerated and may further improve risk biomarker modulation. The increase in adiponectin when ω-3 FA is added to weight loss is of particular interest given that adiponectin opposes the oncogenic effect of leptin and is associated with improved insulin sensitivity and reduced mTOR signaling. Further study is warranted with enough subjects to detect between-group differences.

Citation Format: Carol J Fabian, Christie A Befort, Debra K Sullivan, Susan E Carlson, Jennifer L Nydegger, Amy L Kreutzjans, Kandy R Powers, Teresa A. Phillips, Trina Metheny, Carola M Zalles, Erin D Giles, Stephen D Hursting, Bruce F Kimler. Randomized trial of 12 months of omega-3 fatty acids vs placebo during a weight loss intervention in post-menopausal women at increased risk for breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD11-02.

Abstract 1120: Randomized clinical trial of a flaxseed lignan in pre-menopausal women at high risk for development of breast cancer

Breast cancer prevention strategies for young pre-menopausal women must have minimal side effects and accommodate potential future child-bearing. Based on epidemiologic evidence and informed by a single-arm pilot study, we conducted a multi-institutional, placebo-controlled Phase IIB trial of the lignan secoisolariciresinol diglycoside (SDG) found in high concentrations in flaxseed. Benign breast tissue was acquired by random periareolar fine needle aspiration (RPFNA) from pre-menopausal women at increased risk for breast cancer during the follicular phase as estimated by dates. Those with cytologic hyperplasia and ≥2% positive cells by Ki-67 immunocytochemistry were eligible for randomization 2:1 to daily Brevail® (50 mg SDG) or placebo. After 12 months, RPFNA and blood for hormone assays were repeated. The primary endpoint was difference in change in Ki-67 between the randomization groups. A planned accrual of 230 was to provide an 80% power of detecting a 2.5% reduction in Ki-67 for the SDG group vs no reduction in the placebo group. Accrual was slower than anticipated and the study was closed with 180 enrollees at five sites. 152 (51 placebo, 101 SDG) sets of paired specimens were evaluable for the primary endpoint. Baseline Ki-67 was a median of 4.1% (range, 2.0 - 26.8%), with no difference between arms (Mann-Whitney nonparametric test, p=0.34). Both arms showed a decrease in percent Ki-67 over time (Wilcoxon signed rank test; p=0.034 for placebo, p=0.001 for SDG). Although Ki-67 reduction was greater in the SDG arm (median of -1.8% vs -1.2%), there was no statistically significant difference between the two arms (Mann-Whitney, p=0.72). Since luteal phase progesterone affects proliferation, we excluded 35 women that by serum progesterone levels could not be confirmed to be in the same phase of the menstrual cycle at baseline and off-study. Analyzing the remaining 117 for Ki-67 (42 placebo, 75 SDG), there was no significant change for the placebo arm (Wilcoxon, p=0.14) but the significant change in the SDG arm persisted (p=0.002). As an exploratory analysis, assessment of gene expression was performed by RT-qPCR on 77 pairs of non-bloody RPFNA specimens. 22 had significant ERα gene expression changes (defined &lt;0.5 or &gt;2.0 fold changes). There was no significant change over time for the placebo group (7/10 increases, Wilcoxon, p=0.16), but there was significant change for the SDG group (10/12 decreases, p=0.027). There was also a significant difference between the groups (Mann-Whitney, p=0.018). While the primary trial result is null, there is supportive evidence SDG may favorably affect cell proliferation and estrogen signaling in premenopausal women at high risk for development of breast cancer. Supported by Susan G. Komen Promise Grant KG101039. Study agent (Brevail®, placebo) provided by Lignan Research Inc. (later Barlean's Oils) which was otherwise not involved in the design, conduct, or analysis of the study.

Citation Format: Carol J. Fabian, Seema A. Khan, Judy E. Garber, William C. Dooley, Lisa D. Yee, Carola M. Zalles, Trina Metheny, Teresa A. Phillips, Jinxiang Hu, Brian K. Petroff, Stephen D. Hursting, Bruce F. Kimler. Randomized clinical trial of a flaxseed lignan in pre-menopausal women at high risk for development of breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1120.

Randomized Phase IIB Trial of the Lignan Secoisolariciresinol Diglucoside in Premenopausal Women at Increased Risk for Development of Breast Cancer

We conducted a multiinstitutional, placebo-controlled phase IIB trial of the lignan secoisolariciresinol diglucoside (SDG) found in flaxseed. Benign breast tissue was acquired by random periareolar fine needle aspiration (RPFNA) from premenopausal women at increased risk for breast cancer. Those with hyperplasia and ≥2% Ki-67 positive cells were eligible for randomization 2:1 to 50 mg SDG/day (Brevail) versus placebo for 12 months with repeat bio-specimen acquisition. The primary endpoint was difference in change in Ki-67 between randomization groups. A total of 180 women were randomized, with 152 ultimately evaluable for the primary endpoint. Median baseline Ki-67 was 4.1% with no difference between arms. Median Ki-67 change was -1.8% in the SDG arm (P = 0.001) and -1.2% for placebo (P = 0.034); with no significant difference between arms. As menstrual cycle phase affects proliferation, secondary analysis was performed for 117 women who by progesterone levels were in the same phase of the menstrual cycle at baseline and off-study tissue sampling. The significant Ki-67 decrease persisted for SDG (median = -2.2%; P = 0.002) but not placebo (median = -1.0%). qRT-PCR was performed on 77 pairs of tissue specimens. Twenty-two had significant ERα gene expression changes (<0.5 or >2.0) with 7 of 10 increases in placebo and 10 of 12 decreases for SDG (P = 0.028), and a difference between arms (P = 0.017). Adverse event incidence was similar in both groups, with no evidence that 50 mg/day SDG is harmful. Although the proliferation biomarker analysis showed no difference between the treatment group and the placebo, the trial demonstrated use of SDG is tolerable and safe.

Effects of Weight Loss and Weight Regain on Circulating Biomarkers in Overweight/Obese Breast Cancer Survivors Enrolled in a Weight Loss Trial in the Rural Midwest

BACKGROUND

Obesity is associated with worse breast cancer prognosis, however little is known about the level of weight loss required to improve pathway biomarkers. The effects of weight regain on biomarkers are also largely unknown.

METHODS

Overweight/obese breast cancer survivors enrolled in an 18-month behavioral weight loss trial provided weight and serum biomarkers [leptin, adiponectin, insulin, plasminogen activator inhibitor-1 (PAI-1), IL-6, TNFα, and hepatocyte growth factor HGF] at baseline, 6, and 18 months (n = 138). Change in biomarkers over time and by weight loss thresholds were examined.

RESULTS

Mean weight loss at 6 months was 13.3 ± 5.0 kg; from 6 to 18 months, mean regain was 4.0 ± 5.2 kg. Favorable biomarker modulations were observed at 6 months for leptin, adiponectin, insulin, PAI-1, IL-6, and HGF (P < 0.006 to P < 0.0001). These changes remained significant overall at 18 months despite attenuation in some. Women who lost <10% of baseline weight showed significantly smaller modulation effects for leptin (P < 0.0001), adiponectin:leptin (A/L) ratio (P < 0.0001), PAI-1 (P < 0.001), and insulin (P = 0.003) compared with women who lost >10%. Women who lost >10% observed a significant increase in adiponectin (P < 0.0001), and these women continued to show improved adiponectin from 6 to 18 months despite weight regain. Physical activity contributed additional effects on biomarker change for leptin, A/L ratio, and PAI-1.

CONCLUSIONS

These findings are consistent with a clinical target of 10% weight.

IMPACT

Sustained increases in adiponectin likely confer benefits for breast cancer prognosis even with weight regain.

Abstract PD3-06: Biomarker modulation by bazedoxifene and conjugated estrogen (Duavee®) in women at high risk for development of breast cancer

Agents which both reduce risk for development of breast cancer and relieve vasomotor symptoms are likely to have good uptake and adherence. We conducted a pilot study with 6 months of the tissue selective estrogen complex bazedoxifene (20 mg) and conjugated estrogen (0.45 mg) (Duavee®) to assess feasibility and effects on biomarkers. Risk biomarkers for postmenopausal breast cancer included fully automated mammographic volumetric density (Volpara®), benign breast tissue Ki-67, and serum levels of progesterone, IGF-1 and IGFBP3, bioavailable estradiol and testosterone. Exploratory biomarkers included selected estrogen and progesterone responsive gene expression in benign breast tissue. 28 peri- and post-menopausal women at increased risk for breast cancer were enrolled; 13 in Cohort A with baseline Ki-67 &lt; 1% and 15 in Cohort B with baseline Ki-67 of 1-4%. All completed the study with &gt; 85% drug adherence. An improvement in median hot flash score from 15 at baseline to 0 at 6 months, and menopause specific quality of life total, vasomotor and sexual domain scores were also observed (p&lt; 0.001). Significant changes in risk biomarkers, uncorrected for multiple comparisons, were a decrease in mammographic fibroglandular volume (p=0.043); decreases in serum progesterone, bioavailable testosterone, and IGF-1 (p&lt;0.01); and for women from Cohort B, a reduction in Ki-67 (p=0.017) despite an increase in serum bioavailable estradiol. Unsupervised cluster analysis of RT-qPCR results indicated two clusters with differences in change in early estrogen response genes including ERS1, TFF1, GREB1a, PGR and AREG. The 10 women in one cluster tended to have increased expression of two or more of early estrogen response genes, but not increased expression of CCND1 (cyclin D1) or genes downstream of activated progesterone receptor such as STAT5a, PdK4, and STK. A trend towards decrease in several genes with predominant stromal expression implicated in breast cancer development including FASN, LEP, CXCL12, SDF1a and B, and CYP19A1 was observed. The 17 women in cluster 2 by contrast exhibited predominately decreased expression of early estrogen response genes. Given the favorable effects on vasomotor symptoms and risk biomarkers, a placebo-controlled Phase IIB trial is warranted.

This study was supported in part by grants from the Breast Cancer Research Foundation (BCRF-16-049, BCRF-17-049, BCRF-18-049); and an NIH Clinical and Translational Science Award grant (UL1 TR000001, formerly UL1RR033179) awarded to the University of Kansas Medical Center, and an internal clinical pilot grant program of the KUMC Research Institute.

Citation Format: Carol J Fabian, Lauren Nye, Teresa A Phillips, Onalisa Winblad, Carola M Zalles, Christy R Hagan, Merit L Goodman, Byron J Gajewski, Devin C Koestler, Prabhakar Chalise, Bruce F Kimler. Biomarker modulation by bazedoxifene and conjugated estrogen (Duavee®) in women at high risk for development of breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD3-06.

Abstract P1-14-01: Feasibility study of moderate dose omega 3 fatty acid supplementation in premenopausal women at high risk for breast cancer considering future pregnancy

Background: 11% of women developing breast cancer are pre-menopausal women of childbearing potential under the age of 45. Pregnancy and breast feeding provide long term protection for breast cancer when they occur at an early age. The reasons for protection are poorly understood but likely involve both changes in the immune microenvironment and ductal and lobular epithelial differentiation. This pilot study is addressing a potential prevention strategy in a population otherwise excluded from breast cancer prevention trials and not eligible for standard of care chemoprevention.

Methods: Eligible individuals included pre-menopausal women ages 21-40 that were considering future pregnancy and are at high risk for breast cancer based on family history, prior precancerous biopsy, or 5-year Gail model risk estimate of ≥ 1.7% or 10-year Tyrer-Cuzick risk of 2x population risk as listed in the model. Participants were enrolled and baseline tissue collection included random periareolar fine-needle aspiration (RPFNA) of breast, as well as collection of blood, urine and stool. Women were asked to take two capsules of Omega-3-Acid Ethyl Esters daily (a total of 750 mg DHA and 930 mg EPA) for six months. Post-intervention visit included repeat tissue collection. If women were pregnant at time of post-intervention visit, RPFNA was not done. Baseline and post-intervention DHA Food Frequency Questionnaire (FFQ) and the BCPT Questionnaire were administered. The intervention length was shortened for some participants due to the study ending.

Objectives: 1) To determine feasibility of a breast cancer prevention intervention study in this cohort of pre-menopausal women at high risk for breast cancer and considering future pregnancy, 2) measure compliance with the omega-3 fatty acid supplement in this population, 3) identify novel biomarkers modulated by moderate dose omega-3 fatty acids in this population.

Results: Ten women were successfully enrolled at an average rate of 1.5/month from a single center high risk breast clinic. Of the ten women enrolled, median age was 33 years (range 22-37, ±5.04 stdev), 70% married, 80% Non-Hispanic White, 10% of Ashkenazi Jewish descent and 40% reported having a genetic mutation. Feasibility was achieved with 80% (8 out of 10) of participants returning for post-intervention visit. Reasons given for discontinuation of study were (n=1) side effect from supplement (bloating) and (n=1) scheduling conflicts. Of the eight women who completed the off study visit, two chose not to undergo the off study RPFNA due to discomfort with initial procedure or time commitment. Self-reported pill count showed an average of three missed pills/month. Grade 1 related adverse events reported included odor, nausea and flatulence. Post-intervention, more participants reported diarrhea, vaginal discharge and bleeding, weight gain, general aches and dizziness on BCPT items compared to baseline. Change in benign breast tissue biomarkers will be reported including breast tissue cytomorphology, Ki67, fatty acid analysis and selected gene expression.

Conclusion: It is feasible to recruit premenopausal women considering future pregnancy to a breast cancer prevention trial with a minimally invasive sampling procedure. Results from this trial will inform a larger randomized prevention trial.

Citation Format: Lauren E Nye, Jennifer R Klemp, Kandy R Powers, Anne P O'Dea, Kendra A Cruz, Amy L Kreutzjans, Trina Metheny, Teresa A Phillips, Susan E Carlson, Bruce F Kimler, Carol J Fabian. Feasibility study of moderate dose omega 3 fatty acid supplementation in premenopausal women at high risk for breast cancer considering future pregnancy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-14-01.

Effect of Bazedoxifene and Conjugated Estrogen (Duavee) on Breast Cancer Risk Biomarkers in High-Risk Women: A Pilot Study

Interventions that relieve vasomotor symptoms while reducing risk for breast cancer would likely improve uptake of chemoprevention for perimenopausal and postmenopausal women. We conducted a pilot study with 6 months of the tissue selective estrogen complex bazedoxifene (20 mg) and conjugated estrogen (0.45 mg; Duavee) to assess feasibility and effects on risk biomarkers for postmenopausal breast cancer. Risk biomarkers included fully automated mammographic volumetric density (Volpara), benign breast tissue Ki-67 (MIB-1 immunochemistry), and serum levels of progesterone, IGF-1, and IGFBP3, bioavailable estradiol and testosterone. Twenty-eight perimenopausal and postmenopausal women at increased risk for breast cancer were enrolled: 13 in cohort A with baseline Ki-67 < 1% and 15 in cohort B with baseline Ki-67 of 1% to 4%. All completed the study with > 85% drug adherence. Significant changes in biomarkers, uncorrected for multiple comparisons, were a decrease in mammographic fibroglandular volume (P = 0.043); decreases in serum progesterone, bioavailable testosterone, and IGF-1 (P < 0.01), an increase in serum bioavailable estradiol (P < 0.001), and for women from cohort B a reduction in Ki-67 (P = 0.017). An improvement in median hot flash score from 15 at baseline to 0 at 6 months, and menopause-specific quality-of-life total, vasomotor, and sexual domain scores were also observed (P < 0.001). Given the favorable effects on risk biomarkers and patient reported outcomes, a placebo-controlled phase IIB trial is warranted.

Abstract 2425: Moderate to vigorous physical activity reduces visceral adipose tissue in obese breast cancer survivors undergoing a weight loss intervention

Background: Body composition, adipose distribution, and fitness are likely superior to BMI alone in predicting outcomes in obese breast cancer survivors. Visceral adipose tissue (VAT) is thought to be disproportionately responsible for the metabolic and inflammatory changes linking obesity and breast cancer recurrence.

Purpose: Feasibility of achievement of high volume moderate-to-vigorous physical activity (MVPA) and its effect on body composition including VAT and other risk biomarkers in older sedentary, obese breast cancer survivors participating in a behavioral weight loss intervention.

Methods: Modest caloric restriction (350-500 kcal per day) was combined with a study provided YMCA membership and twice weekly personal trainer sessions. MVPA (40-80% of heart rate reserve in older women) was assessed by Garmin Vivoactive smart watches linked to GarminConnect. Total activity was escalated from 100 minutes week 1 to a total of 300 minutes per week by week 9 with a goal of &gt; 200 min/wk as MVPA. Women were evaluated pre- and post-intervention for peak oxygen consumption (VO2peak), body composition by dual energy x-ray absorptiometry (GE Lunar iDXA), and serum levels of adipokines, cytokines, and hormones.

Results: 18 breast cancer survivors were enrolled and completed the 3 months of the behavioral weight loss intervention which included the YMCA membership and twice weekly personal trainer. Median age was 60, 11 had received prior chemotherapy, and 13 were currently taking aromatase inhibitors. Median (and range) baseline anthropomorphic values were BMI 37 (31-43) kg/m2, total mass 95 (76-125) kg, total fat 46 (34-66) kg, and VAT 1.7 (1.0-3.0) kg. All but one had a baseline VAT &gt; 1.17 kg, consistent with elevated risk of metabolic syndrome. 17/18 achieved at least 150 min/wk of MVPA, with a median of 176 (range 55-291) min/wk for weeks 9-12. Fitness measured as VO2peak increased from 18.9 (13.7-25.3) to 21.1 (17.1-31.4) ml/kg/min (p=0.0003; Wilcoxon signed rank test). At 3 months, significant reductions were observed for total mass (median 7%), fat mass (median 13%), and VAT (median 20%, range 1-41%)(p&lt;0.0003); as well as serum leptin, insulin, and leptin: adiponectin ratio (p&lt;0.01). A strong correlation was observed between week 9-12 MVPA and leptin: adiponectin ratio (p=0.001) with more modest correlations between week 9-12 MVPA and VAT loss (p=0.043), and leptin: adiponectin ratio and VAT loss (p=0.013).

Conclusion: High volume moderate-to-vigorous physical activity can be achieved by older, sedentary, obese breast cancer survivors; and this translates to favorable modulation of body composition including VAT measures and serum risk biomarkers.

Citation Format: Carol J. Fabian, Jennifer R. Klemp, Jeffrey M. Burns, Eric D. Vidoni, Lauren Nye, Christie A. Befort, Jill M. Hamilton-Reeves, Debra K. Sullivan, Teresa A. Phillips, Stephen D. Hursting, Bruce F. Kimler. Moderate to vigorous physical activity reduces visceral adipose tissue in obese breast cancer survivors undergoing a weight loss intervention [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2425.

Circulating adipose stromal cells as a response biomarker in phase II energy balance trials of obese breast cancer survivors and high-risk women

PURPOSE

Circulating adipose stromal cells (CASC) are thought to be increased in obesity and facilitate angiogenesis, and tumor metastases.

METHODS

CASC were identified from buffy coat peripheral blood mononuclear cells (PBMCs) by flow cytometry as CD34^brightCD31^- CD45^- and CASC frequency was compared to adiposity measures in 33 women at increased risk for breast cancer. Feasibility of CASC as a response biomarker for a diet and exercise intervention in ten breast cancer survivors was then explored.

RESULTS

For 33 high-risk women, median CASC frequency was 9.7 per million PBMCs and trended positively with body mass index, fat mass index (FMI), and percent android fat. Correlation was significant when BMI was dichotomized at > versus < 35 kg/m² (p = 0.02). For ten breast cancer survivors with a median BMI of 37 kg/m², median CASC frequency was 16.4 per million PBMCs. In univariate analyses, change in BMI, total fat and visceral fat were significantly correlated with change in CASC frequency. On multivariate analysis, change in visceral adipose had the strongest association with change in CASC frequency (p < 0.00078).

CONCLUSIONS

The association between the reduction in visceral adipose tissue and the decrease in frequency of circulating adipose stromal cells suggests that the latter might be a useful biomarker in clinical trials of obese breast cancer survivors undergoing a weight loss intervention.

Abstract 3261: Pilot study of the combination of bazedoxifene and conjugated estrogen to modulate risk biomarkers in women with hot flashes at increased risk for breast cancer

Uptake of anti-hormonal agents for primary prevention of breast cancer is poor due to concern about side effects, especially induction of menopausal symptoms. A combination of 20 mg bazedoxifene plus 0.045 mg conjugated estrogen is FDA approved (as Duavee®) for treatment of hot flashes and prevention of osteoporosis in postmenopausal women with a uterus. We undertook a pilot study to assess the feasibility of using this formulation as a breast cancer prevention agent in women at increased risk for development of breast cancer. Feasibility was to be assessed by accrual, retention, and documentation of a lack of enhanced proliferation in benign breast tissue acquired by random periareolar fine needle aspiration (RPFNA). Eligibility criteria included risk &gt;2X that of average risk woman for age group, postmenopausal having hot flashes or night sweats and not on systemic hormone replacement, and at least 500 cells on a baseline RPFNA. Women were ineligible if they had LCIS or DCIS, a BRCA1/2 germline mutation, had had a hysterectomy, or had &gt;4% Ki-67 positive cells by immunocytochemistry. Fasting blood draw, digital mammography with Volpara software, and DXA scan for body composition was performed at baseline along with QOL questionnaires. Women then received Duavee® daily for 6 months, followed by repeat of baseline tests. We accrued the first 20 subjects in 14 months. Many of the women followed in our cohort and interested in the trial were not eligible due to prior hysterectomy, prior LCIS or a high penetrance gene mutation. Thus accrual was slower than anticipated. All women have reported improvement in hot flash frequency and intensity. None have discontinued prematurely or had a study related serious adverse event. Fourteen women have completed the 6-month intervention and are evaluable for modulation of biomarkers. There have been no protocol-defined increases in proliferation (to &gt;2% Ki-67 for baseline Ki-67 &lt;1% or doubling if baseline Ki-67 ≥1%), with 10 of 14 paired specimens exhibiting a decrease. Ten women had Volpara fibroglandular assessments pre- and post-study with a median relative decrease of 11% (8 decreased and 2 increased). For the first ten subjects where serum hormones and growth factors were assessed in paired assays, favorable modulation was observed for estradiol, testosterone, SHBG, bioavailable testosterone, IGF-1, and the molar ratio of IGF1:IGFBP3. A primary prevention trial in symptomatic women appears feasible given the favorable initial results. The current pilot will continue to accrue so as to inform the design of a randomized, placebo-controlled Phase II trial of Duavee® in women at risk for breast cancer. Financial support provided by grants from the Breast Cancer Research Foundation (BCRF-16-049, BCRF-17-049). Duavee® provided by Pfizer, Inc. which was not involved in design, conduct, or analysis of the study.

Citation Format: Carol J. Fabian, Kandy R. Powers, Jennifer L. Nydegger, Amy L. Kreutzjans, Trina Metheny, Teresa A. Phillips, Lauren Nye, Carola M. Zalles, Bruce F. Kimler. Pilot study of the combination of bazedoxifene and conjugated estrogen to modulate risk biomarkers in women with hot flashes at increased risk for breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3261.

Modulation of Breast Cancer Risk Biomarkers by High-Dose Omega-3 Fatty Acids: Phase II Pilot Study in Premenopausal Women

Higher intakes of the omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to the omega-6 arachidonic acid (AA) have been variably associated with reduced risk of premenopausal breast cancer. The purpose of this pilot trial was to assess feasibility and explore the effects of high-dose EPA and DHA on blood and benign breast tissue risk biomarkers before design of a placebo-controlled phase IIB trial. Premenopausal women with evidence of hyperplasia ± atypia by baseline random periareolar fine needle aspiration were given 1860 mg of EPA + 1500 mg of DHA ethyl esters daily for 6 months. Blood and benign breast tissue were sampled during the same menstrual cycle phase prestudy and a median of 3 weeks after last dose. Additional blood was obtained within 24 hours of last dose. Feasibility, which was predefined as 50% uptake, 85% retention, and 70% compliance, was demonstrated with 46% uptake, 94% completion, and 85% compliance. Cytologic atypia decreased from 77% to 38% (P = 0.002), and Ki-67 from a median of 2.1% to 1.0% (P = 0.021) with an increase in the ratio of EPA + DHA to AA in erythrocyte phospholipids but no change in blood hormones, adipokines, or cytokines. Exploratory breast proteomics assessment showed decreases in several proteins involved in hormone and cytokine signaling with mixed effects on those in the AKT/mTOR pathways. Further investigation of EPA plus DHA for breast cancer prevention in a placebo-controlled trial in premenopausal women is warranted.

Clinical Trial of Acolbifene in Premenopausal Women at High Risk for Breast Cancer

The purpose of this study was to assess the feasibility of using the selective estrogen receptor modulator (SERM) acolbifene as a breast cancer prevention agent in premenopausal women. To do so, we assessed change in proliferation in benign breast tissue sampled by random periareolar fine-needle aspiration (RPFNA) as a primary endpoint, along with changes in other risk biomarkers and objective and subjective side effects as secondary endpoints. Twenty-five women with cytologic hyperplasia ± atypia and ≥2% of breast epithelial cells staining positive for Ki-67, received 20 mg acolbifene daily for 6-8 months, and then had benign breast tissue and blood risk biomarkers reassessed. Ki-67 decreased from a median of 4.6% [interquartile range (IQR), 3.1%-8.5%] at baseline to 1.4% (IQR, 0.6%-3.5%) after acolbifene (P < 0.001; Wilcoxon signed-rank test), despite increases in bioavailable estradiol. There were also significant decreases in expression (RT-qPCR) of estrogen-inducible genes that code for pS2, ERα, and progesterone receptor (P ≤ 0.026). There was no significant change in serum IGF1, IGFBP3, IGF1:IGFBP3 ratio, or mammographic breast density. Subjective side effects were minimal with no significant increase in hot flashes, muscle cramps, arthralgias, or fatigue. Objective measures showed a clinically insignificant decrease in lumbar spine bone density (DEXA) and an increase in ovarian cysts but no change in endometrial thickness (sonography). In summary, acolbifene was associated with favorable changes in benign breast epithelial cell proliferation and estrogen-inducible gene expression but minimal side effects, suggesting a phase IIB placebo-controlled trial evaluating it further for breast cancer prevention.

Modulation of Breast Cancer Risk Biomarkers by High-Dose Omega-3 Fatty Acids: Phase II Pilot Study in Postmenopausal Women

Associational studies suggest higher intakes/blood levels of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to the omega-6 arachidonic acid (AA) are associated with reduced breast cancer risk. We performed a pilot study of high-dose EPA + DHA in postmenopausal women to assess feasibility before initiating a phase IIB prevention trial. Postmenopausal women with cytologic evidence of hyperplasia in their baseline random periareolar fine needle aspiration (RPFNA) took 1,860 mg EPA +1500 mg DHA ethyl esters daily for 6 months. Blood and breast tissue were sampled at baseline and study conclusion for exploratory biomarker assessment, with P values uncorrected for multiple comparisons. Feasibility was predefined as 50% uptake, 80% completion, and 70% compliance. Trial uptake by 35 study entrants from 54 eligible women was 65%, with 97% completion and 97% compliance. Favorable modulation was suggested for serum adiponectin (P = 0.0027), TNFα (P = 0.016), HOMA 2B measure of pancreatic β cell function (P = 0.0048), and bioavailable estradiol (P = 0.039). Benign breast tissue Ki-67 (P = 0.036), macrophage chemoattractant protein-1 (P = 0.033), cytomorphology index score (P = 0.014), and percent mammographic density (P = 0.036) were decreased with favorable effects in a proteomics array for several proteins associated with mitogen signaling and cell-cycle arrest; but no obvious overall effect on proteins downstream of mTOR. Although favorable risk biomarker modulation will need to be confirmed in a placebo-controlled trial, we have demonstrated feasibility for development of high-dose EPA and DHA ethyl esters for primary prevention of breast cancer.

Exploring the experiences of novice clinical instructors in physical therapy clinical education: a phenomenological study

OBJECTIVE

To explore the perceptions of novice physical therapy clinical instructors (CIs) about their interactions and teaching behaviours with physical therapy students.

DESIGN

A phenomenological approach using semi-structured interviews and a focus group.

PARTICIPANTS

Six novice physical therapy CIs (less than two years as a CI and supervised fewer than three students) were recruited purposefully from a large metropolitan area in the USA. All participants were credentialed by the American Physical Therapy Association as CIs.

MAIN OUTCOME MEASURES

Transcripts of interview data and focus group data were analysed using interpretative analysis for themes and subthemes.

RESULTS

Participants viewed the transition of students from the classroom to the clinic as their primary role, using strategies of 'providing a way in', 'fostering critical thinking', 'finding a balance', 'overcoming barriers' and 'letting go'.

CONCLUSION

While novice CIs showed skill in fostering student reflection and providing orientation, they struggled with student autonomy and balancing the competing obligations of patient care and clinical instruction. They expressed issues related to anxiety and lack of confidence. In the future, novice CIs could benefit from training and support in these areas.

The prognostic value of BRCA1 promoter methylation in early stage triple negative breast cancer

Introduction

Methylation of the BRCA1 promoter is frequent in triple negative breast cancers (TNBC) and results in a tumor phenotype similar to BRCA1-mutated tumors. BRCA1 mutation-associated cancers are more sensitive to DNA damaging agents as compared to conventional chemotherapy agents. It is not known if there is an interaction between the presence of BRCA1 promoter methylation (PM) and response to chemotherapy agents in sporadic TNBC. We sought to investigate the prognostic significance of BRCA1 PM in TNBC patients receiving standard chemotherapy.

Methods

Subjects with stage I-III TNBC treated with chemotherapy were identified and their formalin-fixed paraffin-embedded (FFPE) tumor specimens retrieved. Genomic DNA was isolated and subjected to methylation-specific PCR (MSPCR).

Results

DNA was isolated from primary tumor of 39 subjects. BRCA1 PM was detected in 30% of patients. Presence of BRCA1 PM was associated with lower BRCA1 transcript levels, suggesting epigenetic BRCA1 silencing. All patients received chemotherapy (anthracycline:90%, taxane:69%). At a median follow-up of 64 months, 46% of patients have recurred and 36% have died. On univariate analysis, African-American race, node positivity, stage, and BRCA1 PM were associated with worse RFS and OS. Five year OS was 36% for patients with BRCA1 PM vs. 77% for patients without BRCA1 PM (p=0.004). On multivariable analysis, BRCA1 PM was associated with significantly worse RFS and OS.

Conclusions

We show that BRCA1 PM is common in TNBC and has the potential to identify a significant fraction of TNBC patients who have suboptimal outcomes with standard chemotherapy.

Favorable modulation of benign breast tissue and serum risk biomarkers is associated with > 10 % weight loss in postmenopausal women

We conducted a phase II feasibility study of a 6-month behavioral weight loss intervention in postmenopausal overweight and obese women at increased risk for breast cancer and the effects of weight loss on anthropomorphic, blood, and benign breast tissue biomarkers. 67 women were screened by random peri-areolar fine-needle aspiration, 27 were registered and 24 participated in the interventional phase. The 24 biomarker evaluable women had a median baseline BMI of 34.2 kg/m(2) and lost a median of 11 % of their initial weight. Significant tissue biomarker modulation after the 6-month intervention was noted for Ki-67 (if restricted to the 15 women with any Ki-67 at baseline, p = 0.041), adiponectin to leptin ratio (p = 0.003); and cyclin B1 (p = 0.001), phosphorylated retinoblastoma (p = 0.005), and ribosomal S6 (p = 0.004) proteins. Favorable modulation for serum markers was observed for sex hormone-binding globulin (p < 0.001), bioavailable estradiol (p < 0.001), bioavailable testosterone (p = 0.033), insulin (p = 0.018), adiponectin (p = 0.001), leptin (p < 0.001), the adiponectin to leptin ratio (p < 0.001), C-reactive protein (p = 0.002), and hepatocyte growth factor (p = 0.011). When subdivided by <10 or >10 % weight loss, change in percent total body and android (visceral) fat, physical activity, and the majority of the serum and tissue biomarkers were significantly modulated only for women with >10 % weight loss from baseline. Some factors such as serum PAI-1 and breast tissue pS2 (estrogen-inducible gene) mRNA were not significantly modulated overall but were when considering only those with >10 % weight loss. In conclusion, a median weight loss of 11 % over 6 months resulted in favorable modulation of a number of anthropomorphic, breast tissue and serum risk and mechanistic markers. Weight loss of 10 % or more should likely be the goal for breast cancer risk reduction studies in obese women.

High-dose omega-3 fatty acid supplementation to modulate breast tissue biomarkers in premenopausal women at high risk for development of breast cancer

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Background: We conducted a pilot study of high dose omega-3 fatty acid (FA) supplementation in pre-menopausal women to determine if risk biomarkers for breast cancer in benign breast tissue sampled by random peri-areolar aspiration (RPFNA) could be favorably modulated and to acquire preliminary data on possible mechanism of action. Methods: 36 pre-menopausal women at increased risk for breast cancer were accrued to a trial of 6-month intervention with 4 g daily of omega-3-acid ethyl esters [1.86 g eicosapentaenoic acid (EPA), 1.5 g docosahexaenoic acid (DHA)]. To date, 31 subjects have completed study with RPFNA performed pre- and post-intervention in the follicular phase of the menstrual cycle and specimens evaluated for cytomorphology and proliferation (Ki-67). FA composition was determined in plasma, red blood cells, and RPFNA specimens. Additional specimens were frozen for assessment of hormones, a panel of 11 adipokines and cytokines, and gene expression. Results: The ratio of (EPA+DHA):Arachidonic Acid (AA) levels increased significantly in plasma and erythrocytes by a median of three-fold. There was a significant decrease in blood EPA+DHA between discontinuation at 6 months and 2 weeks later when RPFNA was performed. Despite that, there was favorable modulation for cytologic evidence of atypia (81% at baseline to 42% at off-study; p=0.003), Masood score (medians of 15 to 14; p=0.001), number of epithelial cells recovered (p=0.004) and Ki-67 expression (p=0.025 for 30 women with any Ki-67 at baseline, medians of 1.9% to 0.9%). Serum assays have been completed for 24 subjects. No statistically significant changes were observed for estradiol, testosterone, progesterone, SHBG, IGF-1, IGFBP-3. There was a trend (p=0.056) towards a decrease in resistin. To date, only two subjects have discontinued the study early; grade 2 or greater gastrointestinal side effects have been reported by only two subjects. Conclusions: Favorable modulation of tissue risk biomarkers, cytologic atypia and proliferation along with good tolerability suggests that high dose omega-3 FA esters should be tested further in a placebo controlled trial. Clinical trial information: NCT01252277.

Abstract 158: Modulation of breast tissue biomarkers by high dose omega-3 fatty acid supplementation in women at high risk for development of breast cancer

Background. Previously, we had observed that women at high risk for development of breast cancer were more likely to exhibit cytologic hyperplasia with atypia in specimens acquired by random periareolar fine needle aspiration (RPFNA) if they had low intake and/or low plasma, red blood cell, or breast tissue levels of omega-3 relative to omega-6 fatty acids. We evaluated the effect of high dose omega-3 supplementation on breast tissue markers in two parallel pilot studies, one of pre-menopausal and one of post-menopausal women. Methods. 36 pre-menopausal and 35 post-menopausal women at high risk for breast cancer had breast tissue harvested by RPFNA before and after a 6-month intervention with 4 g daily of omega-3-acid ehyl esters [1.86 g eicosapentaenoic acid (EPA), 1.5 g docosahexaenoic acid (DHA)]. Premenopausal women were aspirated in the follicular phase of the menstrual cycle. Specimens were evaluated for tissue risk biomarkers including cytomorphology, proliferation (Ki-67). Fatty acid composition was determined in plasma, red blood cells, and breast RPFNA specimens. Additional blood and frozen breast tissue was reserved for assessment of hormones, adipokines, cytokines and gene expression. Results. To date, only two of the 71 subjects have discontinued the study early, while 50 subjects have completed study and are evaluable for modulation of tissue biomarkers. Grade 2 or greater gastrointestinal side effects have been reported by only seven subjects. Favorable modulation was observed for cytologic evidence of atypia (70% to 44%; p=0.012), Masood score (medians of 15 to 14; p=0.001), number of epithelial cells recovered (p=0.002), and Ki-67 expression (p=0.059 if all subjects are included even if they did not exhibit Ki-67 staining at baseline, medians of 1.7% to 0.8%; or p=0.001 for 27 women with baseline Ki-67 &gt;1.5%, medians of 3.2% to 1.4%). Modulation was more prevalent (and was statistically significant for all variables) in pre-menopausal women than in post-menopausal women. Fatty acid assessment, adipokine and cytokine assays are batched to minimize variability and all results are not yet available. Preliminary results indicate that the ratio of omega-3:omega-6 fatty acids increased in erythrocytes and plasma by two-fold after 6 months of the high dose omega-3 fatty acid intervention. Conclusion. High dose supplementation with omega-3 fatty acids is well-tolerated in healthy women at high risk for development of breast cancer and was associated with favorable modulation of the tissue risk biomarkers of cytologic atypia and proliferation. This strategy will be explored further as a promising intervention that may reduce risk for development of breast cancer. Supported in part by funding from the Breast Cancer Research Foundation and the Kansas Bioscience Authority. Study agent was provided by GlaxoSmithKline.

Citation Format: Carol J. Fabian, Bruce F. Kimler, Carola M. Zalles, Trina Metheny, Jessica A. Box, Jennifer L. Nydegger, Teresa A. Phillips, Brandon H. Hidaka, Susan E. Carlson. Modulation of breast tissue biomarkers by high dose omega-3 fatty acid supplementation in women at high risk for development of breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 158. doi:10.1158/1538-7445.AM2013-158

Assessment of RNA in human breast tissue sampled by random periareolar fine needle aspiration and ductal lavage and processed as fixed or frozen specimens

Ductal lavage (DL) and random periareolar fine needle aspiration (RPFNA) have both been proposed as minimally invasive techniques to sample breast tissue during breast cancer prevention trials. Laser capture microdissection (LCM), linear RNA amplification and quantitative real-time polymerase chain reaction (qPCR) theoretically overcome the limitations of small specimen size obtained with DL and RPFNA. In order to test the yield, relative stability and amplifiability of RNA from fixed and archived RPFNA and DL specimens, breast tissue was sampled from individual high risk women (n=9) by both DL and RPFNA. RPFNA samples showed good RNA/cDNA yield and amplification while only 2 of 9 of the paired DL specimens had cDNA of adequate quality for subsequent PCR. One and two rounds of linear amplification provided approximately a 200- and 20,000-fold enrichment of RNA, respectively. PCR analysis consistently detected ER and COX-1 mRNA in the majority of RPFNA samples examined while pS2, PCNA, VEGF and survivin expression varied with subject. RNA yield and/or stability was greater for fixed and archived RPFNA than DL specimens of breast tissue. In a subsequent study examining an expanded biomarker gene panel in fixed vs. frozen RPFNA samples, mRNA profiles and ranked relative mRNA abundance were similar (r=0.89) for frozen and fixed RPFNA specimens. In summary, frozen RPFNA samples may be optimal for RNA endpoints in human breast cancer prevention trials but fixed RPFNA specimens allow similar analyses with greater convenience.

Reduction in Ki-67 in benign breast tissue of high-risk premenopausal women with the SERM acolbifene

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Background: Selective Estrogen Receptor Modulators (SERMs) are approved for reduction of risk for breast cancer; however, uptake and use is limited. We conducted a pilot study of a 4th generation SERM to determine tolerability and effect on tissue biomarkers in healthy women at high risk for development of breast cancer. Methods: Premenopausal women at elevated risk for breast cancer were screened by random periareolar fine needle aspiration (RPFNA) performed during the follicular phase of the menstrual cycle. Women were eligible if breast epithelial cells exhibited evidence of cytologic hyperplasia with or without atypia, as well as Ki-67 ≥2% by immunocytochemistry. Following 6-8 months of open-label acolbifene (20 mg/d), the RPFNA was repeated. The primary endpoint was modulation of the proportion of cells that expressed Ki-67. Body composition (DEXA), pelvic sonography, mammographic breast density, and serum levels of IGF-1/IGFBP3 and several bioavailable hormones were assessed pre and post intervention. Results: 76 women were screened by RPFNA, with 25 eligible and enrolled in the intervention over a 9 month period. All 25 (7 on oral contraceptives) subjects completed the study, had a second RPFNA, and were evaluable. Median Ki-67 at baseline was 4.6% (range 2.4 – 21.9%) and off study 1.4% (range 0 – 6.6%); median change was a reduction of 3.0% (range -20.2% to +2.8%; decreased in 23, increased in 2) or a relative reduction of 77%. The end-of-study Ki-67 was significantly less than baseline (p<0.001, 2-tailed Wilcoxon test). There were no statistically significant changes in cytomorphology over this short intervention period. There was a marginal effect on breast density (16 decreased; 8 increased; p=0.067). Adverse events were minimal with greatest grade of 3 reported by 2 subjects, grade 2 by 7 subjects, and grade 1 by 11 subjects. No serious adverse event was reported and no subject discontinued the study due to an AE. Conclusions: Based on preliminary evaluation showing favorable modulation of proliferation and minimal adverse events, further investigation of acolbifene, a fourth generation SERM, as a breast cancer chemoprevention agent for premenopausal women appears warranted. Supported by NO1-CN-35135.

Abstract PD09-04: Weight Loss in Postmenopausal Women Is Associated with Modulation of Serum and Tissue Based Risk Biomarkers

Background

In a pilot study, a structured program of reduced energy diet, physical activity, and weekly group behavioral intervention with other high risk women was successful at producing a median 11% weight loss with at least a 5% weight loss in 88% of subjects. We evaluated the association of weight loss with changes in serum and breast tissue risk and mechanisms of action biomarkers. Methods

High risk postmenopausal women with BMI &gt;25 kg/m2 had breast tissue harvested by random periareolar fine needle aspiration (RPFNA) before and after a 6-month energy balance intervention. Specimens were evaluated for biomarkers including cytomorphology, proliferation (immunocytochemical Ki-67), gene expression by RT-qPCR, and expression of cytokines and adpokines by Luminex assay. Fasting serum was assayed for insulin, glucose, adiponectin, leptin, high sensitivity CRP, IL-6, prolactin, SHBG, estradiol and testosterone using ELISA or Luminex.

Results

For 24 biomarker evaluable subjects, 21 had &gt;5% weight loss (median = 11%). Cytologic atypia was present in 10/24 at baseline and 4/24 at 6 months (p=0.034). For 20 subjects with sufficient cells for assessment of Ki-67 at both times, median baseline Ki-67 was 0.7% and off study 0.3%, with a median change of -0.2% (p=0.19). Statistically significant changes (≥0.003; Wilcoxon) were observed for serum levels of adiponectin, adiponectin:leptin ratio, and SHBG (increases); and leptin, bioavailable estradiol and hsCRP (decreases). Reduction was also observed for insulin (p=0.018) and bioavailable testosterone (p=0.033). These results were duplicated (p≥0.014) by Luminex for adiponectin, leptin, adiponectin: leptin ratio, and insulin; plus hepatocyte growth factor (HGF, decrease). Also, an increase in the adiponectin:leptin ratio was observed for the RPFNA specimens (p=0.012). Gene expression (RT-qPCR) of pS2 was significantly modified (decrease, p=0.035). Further, the weight loss (expressed as relative change) was highly statistically correlated with change (relative) in serum leptin, adiponectin:leptin ratio, SHGB, and free estradiol; as well as with relative change in adiponectin:leptin ratio in RPFNA specimens. Conclusion

Weight loss in high risk postmenopausal women is accompanied by significant modulation of numerous serum and breast tissue-based biomarkers. For several risk and response biomarkers there is a significant correlation between change in the biomarker and the weight loss achieved. This suggests the possibility of identifying mechanisms of action and signaling pathways for dietary/energy balance interventions that may reduce risk for development of breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD09-04.

Reduction in Ki-67 in benign breast tissue of high-risk women with the lignan secoisolariciresinol diglycoside

Preclinical and correlative studies suggest reduced breast cancer with higher lignan intake or blood levels. We conducted a pilot study of modulation of risk biomarkers for breast cancer in premenopausal women after administration of the plant lignan secoisolariciresinol given as the diglycoside (SDG). Eligibility criteria included regular menstrual cycles, no oral contraceptives, a >3-fold increase in 5-year risk, and baseline Ki-67 of ≥2% in areas of hyperplasia in breast tissue sampled by random periareolar fine-needle aspiration (RPFNA) during the follicular phase of the menstrual cycle. SDG (50 mg/d) was given for 12 months, followed by repeat RPFNA. The primary end point was change in Ki-67. Secondary end points included change in cytomorphology, mammographic breast density, serum bioavailable estradiol and testosterone insulin-like growth factor-I and IGF-binding protein-3, and plasma lignan levels. Forty-five of 49 eligible women completed the study with excellent compliance (median = 96%) and few serious side effects (4% grade 3). Median plasma enterolactone increased ∼9-fold, and total lignans increased 16-fold. Thirty-six (80%) of the 45 evaluable subjects showed a decrease in Ki-67, from a median of 4% (range, 2-16.8%) to 2% (range, 0-15.2%; P < 0.001, Wilcoxon signed rank test). A decrease from baseline in the proportion of women with atypical cytology (P = 0.035) was also observed. Based on favorable risk biomarker modulation and lack of adverse events, we are initiating a randomized trial of SDG versus placebo in premenopausal women.

Abstract 2053: Regulation of microRNA-10b by CCN5/WISP-2 in breast cancer: A novel mechanism of CCN5/WISP-2 mediated suppression of invasive front

Metastatic cells are a subset of primary tumor cells that have the skill to complete multi-step metastatic cascades, including dissemination, migration, extravasation, and eventual proliferation) at a discontinuous secondary site. Understanding the molecular biology of cancer metastasis may provide novel intervention strategies to control metastatic lesions, and/or to improve the quality of life for the patients with these advanced diseases. MicoRNAs are naturally occurring single-stranded RNA molecules that posttranscriptionally regulate the expression of target mRNA transcripts. Many of these target mRNA transcripts are involved in cell proliferation, differentiation and apoptosis, processes commonly altered during tumorigenesis. Recent findings have shown that microRNA-10b (miR-10b) is highly expressed in metastatic breast cancer cells and positively regulates cell migration and invasion. Expression of miR-10b is induced by Twist, a transcription factor that binds to putative promoter of miR-10b. We hypothesized that whether nullification of CCN5/WISP-2, an antiinvasive gene has any role in miR-10b expression. We found that nullification of CCN5/WISP-2 in ER-positive noninvasive breast tumor cell upregulates the miR-10b expression. Interestingly, we also found the upregulation of Twist by silencing CCN5/WISP-2. Collectively, we conclude that CCN5/WISP-2 may be a critical regulator of miR-10b expression through the HIF-1α-Twist signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2053.

CCN5/WISP-2 expression in breast adenocarcinoma is associated with less frequent progression of the disease and suppresses the invasive phenotypes of tumor cells

Although previous in vitro studies predicted that CCN5/WISP-2 may act as an anti-invasive gene in breast cancer, the distribution pattern of CCN5 in breast cancer samples is conflicting. Thus, we systematically investigated the CCN5 expression profile in noninvasive and invasive breast tumor samples and its functional relevance in breast cancer progression. The studies showed that CCN5 expression is biphasic, such that in normal samples CCN5 expression is undetectable, whereas its expression is markedly increased in noninvasive breast lesions, including atypical ductal hyperplasia and ductal carcinoma in situ. Further, CCN5 mRNA and protein levels are significantly reduced as the cancer progresses from a noninvasive to invasive type. Additionally, we showed that CCN5 mRNA and protein level was almost undetectable in poorly differentiated cancers compared with the moderately or well-differentiated samples and its expression inversely correlated with lymph node positivity. The result was further supported by evaluating the RNA expression profile in microdissected sections using real-time PCR analysis. Therefore, our data suggest a protective function of CCN5 in noninvasive breast tumor cells. This hypothesis was further supported by our in vitro studies illuminating that CCN5 is a negative regulator of migration and invasion of breast cancer cells, and these events could be regulated by CCN5 through the modulation of the expression of genes essential for an invasive front. These include Snail-E-cadherin signaling and matrix metalloproteinase (MMP)-9 and MMP-2. Collectively, these studies suggest that the protective effect of CCN5 in breast cancer progression may have important therapeutic implications.

Reduction in proliferation with six months of letrozole in women on hormone replacement therapy

The objective of this study was to determine if 6 months of the aromatase inhibitor letrozole, administered to postmenopausal women taking a stable dose of hormone replacement remedy, would be safe and would modulate biomarkers of breast cancer risk. The intent was to reduce the proliferation marker Ki-67 while maintaining adequate systemic levels of estradiol so as to avoid perimenopausal symptoms. Postmenopausal women at high risk for development of breast cancer and taking a stable dose of estrogen or estrogen plus progestin were screened by random periareolar fine needle aspiration (RPFNA). To be eligible, the acquired breast epithelial cells had to be characterized as cytologic atypia or borderline atypia with > or =1,000 epithelial cells on the cytomorphology slide; plus > or =500 epithelial cells on a slide processed for Ki-67 immunocytochemistry. Forty-two women were enrolled in the one arm study and received 2.5 mg letrozole per day for 6 months, followed by repeat assessment of biomarkers. Ki-67 was reduced by a median relative value of 66%. There was no significant change in breast cell cytomorphology; ER weighted index score; serum estradiol, testosterone, or IGF-1:IGFBP-3 ratio; mammographic breast density, or frequency or severity of perimenopausal symptoms. Given the dramatic reduction in proliferation, the effect of letrozole on risk and response biomarkers should be explored further in a randomized, placebo-controlled Phase IIB breast cancer chemoprevention trial.

Detection of biomarker gene expression by real-time polymerase chain reaction using amplified ribonucleic acids from formalin-fixed random periareolar fine needle aspirates of human breast tissue

OBJECTIVE

To address the detection of breast cancer biomarker gene expression in formalin-fixed random periareolar fine needle aspiration (RPFNA) samples of benign breast tissue collected during breast cancer prevention trials by quantitative real-time polymerase chain reaction (qPCR).

STUDY DESIGN

Formalin-fixed breast epithelial cells collected by RPFNA and processed as thin layer preparations were isolated by laser capture microdissection (LCM). Ribonucleic acid (RNA) was extracted and amplified using a single round of T7-based linear amplification followed by quality assessment and biomarker assay using TaqMan chemistry.

RESULTS

More than 80% of RPFNA samples yielded RNA of sufficient quantity and quality for measurement of a panel of biomarker genes following a single round of linear amplification. RNA and protein expression for estrogen receptor alpha, as assessed by LCM/qPCR and immunohistochemistry, were correlated. Amplification plots were similar for cDNA standards and cDNA derived from RPFNA samples.

CONCLUSION

Assessment of gene expression using amplified RNA from microdissected formalin-fixed RPFNAs can increase the number of biomarkers used during breast cancer chemoprevention trials.

In vitro models for studying human uterine and placental macrophages

Human monocytes and macrophages, which are also called mononuclear phagocytes, represent a major arm of the innate immune system. These cells not only protect against infection but are also central to tissue remodeling and production of chemokines, cytokines, and growth factors. Tissue macrophages reside in the human placenta and uterine decidua throughout pregnancy, where they comprise part of the host defense network and facilitate placental and extraembryonic development. The purpose of this chapter is to describe methods for establishing useful models of human uteroplacental macrophages: (1) differentiated U937 myelomonocytic cells, (2) peripheral blood monocytes, (3) peripheral blood monocyte-derived macrophages, (4) decidual macrophages, and (5) placental macrophages.

Analysis of the soluble isoforms of HLA-G mRNAs and proteins

The human major histocompatibility complex (MHC) contains genes encoding the Human Leukocyte Antigens (HLA). Of these antigens, placental immunologists need study only the HLA class I molecules, because HLA class II expression is repressed in the fetal placental cells that are in direct contact with maternal blood and tissues containing maternal immune cells. The class I antigens are subdivided into two general categories. The class Ia antigens are highly polymorphic and are typified by HLA-A, -B, and -C; these are expressed by nearly all somatic cells and stimulate graft rejection when foreign to the host. By contrast, the HLA class Ib antigens, HLA-E, -F, and -G, have restricted expression, few variants, and appear rarely to be immunostimulatory. One class Ia antigen, HLA-C, and the three class Ib antigens are differentially expressed by trophoblast cell subpopulations. In order to understand immune privilege in the pregnant uterus and placenta, it is essential to study the unique structural and functional features of these four genes and their glycoprotein products. In this chapter, we focus on the first class Ib gene identified in human placentas, HLA-G, with emphasis on its two soluble isoforms, HLA-G5 and HLA-G6. We describe methods developed in our laboratory to distinguish mRNAs encoding HLA-G5 and HLA-G6, and antibody-based protocols for identification of the soluble isoforms.

Isolation and culture of term human trophoblast cells

Experimentation with most human cell types is restricted to the use of cell lines, and this limits our ability to extrapolate interpretations to the in vivo condition. However, in studying human trophoblast cells, we have a unique opportunity to obtain large quantities of readily available human tissue. In this chapter, we outline the methodology for purification of human trophoblast cells from term placentas. The procedures are based on enzymatic dissociation of villous placental tissue, followed by gradient centrifugation and immunomagnetic bead purification. Purity may be assessed by immunocytochemistry or flow cytometry using a number of markers to identify both cytotrophoblast cells and cellular contaminants. The resulting cytotrophoblast cell populations have excellent viability and purity, and may be subjected to long-term culture.

Placental cell expression of HLA-G2 isoforms is limited to the invasive trophoblast phenotype

The HLA-G message is alternatively spliced into multiple transcripts, two of which encode soluble isoforms. To initiate studies on the specific functions of the soluble isoforms, we produced soluble rHLA-G1 (rsG1) and rsG2 in human embryonic kidney 293 cells and characterized the proteins. Both isoforms were glycosylated and formed disulfide-bonded oligomers. Recombinant sG1 associated with beta(2)-microglobulin, whereas rsG2 did not. Mouse mAb generated to rsG1 (1-2C3), which identified exclusively sG1, and mAb generated to rsG2 (26-2H11), which identified both soluble and membrane G2 (m/sG2), were used for immunohistochemical isoform mapping studies on placental tissue sections. Soluble G1 protein was abundant in many subpopulations of trophoblast cells, whereas m/sG2 protein was present exclusively in extravillous cytotrophoblast cells. Although both isolated placental villous cytotrophoblast cells and chorion membrane extravillous cytotrophoblast cells contained mRNAs encoding sG1 and sG2, protein expression was as predicted from the immunostains with m/sG2 present only in the invasive trophoblast subpopulation. Analysis of function by Northern and Western blotting demonstrated that both rsG1 and rsG2 inhibit CD8alpha expression on PBMC without changing CD3delta expression or causing apoptotic cell death. Collectively, the studies indicate that: 1) both sG1 and m/sG2 are produced in placentas; 2) transcription and translation are linked for sG1, but not G2; 3) expression of G2 is exclusively associated with the invasive phenotype; and 4) the two isoforms of sG may promote semiallogeneic pregnancy by reducing expression of CD8, a molecule required for functional activation of CTL.

Toxicity of chlorpyrifos adsorbed on humic colloids to larval walleye (Stizostedion vitreum)

After application, organophosphorus insecticides (OPs) are often strongly adsorbed to soil constituents. Because of their relatively low water solubility, OPs may be transferred from field to stream adsorbed on suspended solids. However, we are not aware of research done to evaluate the bioavailability (i.e., toxicity) of OPs transported on suspended solids to fish. We conducted 48-h static toxicity tests to determine the toxicity of chlorpyrifos in aqueous solution and adsorbed on calcium-saturated humic acid (HA) to three larval stages of walleye (Stizostedion vitreum). Three concentrations of chlorpyrifos adsorbed on HA, a HA control, and a chlorpyrifos-only treatment were tested. Fish that survived the 48-h static toxicity tests were analyzed to determine total cholinesterase (ChE) activity. In general, survival of all larval stages of walleye exposed to chlorpyrifos-HA complexes was less than that of walleye exposed to HA controls and the chlorpyrifos-only treatment, which were not toxic to walleye. Cholinesterase inhibition of larval walleye exposed to chlorpyrifos-HA complexes was similar to the ChE inhibition observed in larval walleye exposed to chlorpyrifos in the aqueous phase. These laboratory experiments indicate potential toxicity of chlorpyrifos-soil complexes to larval fish.

Cell-specific expression of B lymphocyte (APRIL, BLyS)- and Th2 (CD30L/CD153)-promoting tumor necrosis factor superfamily ligands in human placentas

Apoptosis-inducing tumor necrosis factor (TNF) ligands and receptors have been reported in human placentas, but the expression patterns of family members lacking this function [a proliferation-inducing ligand (APRIL), B lymphocyte stimulator (BLyS), CD30L/CD153, CD40L/CD154, TNF-related activation-induced cytokine, CD27L/CD70, OX40L, activation-inducible TNF receptor ligand (AITRL)] are incompletely documented or unknown. We therefore investigated expression of these eight ligands and nine of their receptors (B cell maturation antigen, transmembrane activator and calcium-modulator and cyclophilin ligand-interactor, CD30, CD40, receptor activator of nuclear factor-kappaB, osteoprotegerin, CD27, OX40/CD134, AITR). Analysis by reverse transcriptase-polymerase chain reaction revealed mRNAs encoding only three of the ligands (APRIL, BLyS, CD30L/CD153). Immunoblots demonstrated all three proteins in first-trimester and term placentas, and immunohistochemical experiments showed that expression was cell-specific and gestation-related. Although mRNAs encoding receptors for the three expressed ligands were absent, those encoding receptors for all of the unexpressed ligands were detectable. Collectively, the results are consistent with the postulate that nonapoptosis-inducing, placenta-derived TNF superfamily cytokines contribute to the T helper cell type 2 bias required for successful pregnancy. Patterns of placental expression of receptors suggest bidirectional maternal-fetal cytokine communication.

B7 family molecules are favorably positioned at the human maternal-fetal interface

The human placenta utilizes both active and passive mechanisms to evade rejection by the maternal immune system. We investigated the pattern of expression of the B7 family of immunomodulatory molecules B7-H1 (PD-L1), B7-2 (CD86), and B7-1 (CD80) at the term maternal-fetal interface. Northern blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses showed that B7-H1 mRNA is abundant in term placenta and that cytotrophoblasts are sources of this message. Immunohistochemistry demonstrated that B7-H1 is constitutively expressed by the syncytiotrophoblast and by extravillous cytotrophoblasts, both of which are juxtaposed to maternal blood and tissue. By contrast, placental stromal cells, including macrophages, lacked the protein. Expression of B7-H1 protein was low in first-trimester placenta compared to second- and third-trimester tissue (P < 0.05) and was enhanced in cultured cytotrophoblasts by treatment with either interferon-gamma or epidermal growth factor (P < 0.05), suggesting that one or both of these mediators regulates B7-H1 expression in the placenta. RT-PCR and immunofluorescence analysis of term placental tissue revealed different patterns of expression of the immunostimulatory protein, B7-2. In contrast to B7-H1, B7-2 mRNA and protein were absent in cytotrophoblast cells but present in maternal macrophages and some fetal macrophages. The B7-1 mRNA and protein were absent at the maternal-fetal interface. These studies document expression of the B7 family proteins at the maternal-fetal interface and demonstrate that B7-H1 is positioned such that it could facilitate protection of fetal cells against activated maternal leukocytes. Conversely, B7-2 was absent on trophoblasts and was appropriately localized to fetal and maternal macrophages, which may participate in antigen presentation.

Environmental, biological, and methodological factors affecting cholinesterase activity in walleye (Stizostedion vitreum)

Organophosphorus (OP) insecticides have high acute toxicity toward many nontarget vertebrate and invertebrate organisms, but direct measurement of OPs in environmental samples is difficult because their concentrations may fall below detection limits within hours to days after entering aquatic ecosystems. Because OPs exert toxicity through cholinesterase (ChE) inhibition, which may persist for up to several weeks, ChE inhibition has been widely used in aquatic ecosystems as a biomarker for OP exposure in aquatic organisms. However, the biological, environmental, and methodological factors affecting ChE activity have not been well documented and must be considered and understood before ChE activity can be used as a dependable indicator of OP exposure to aquatic organisms. This study examined the influence of water temperature, size of larval and juvenile walleye (Stizostedion vitreum), stress, long-term storage, postmortem changes, and methods of euthanasia on ChE activity. Water temperature (17.2, 20.9, and 24.6 degrees C), stress, long-term storage (up to 180 days), postmortem changes, and method of euthanasia had no effect on ChE activity of walleye. There was a strong positive correlation (r = 0.87) between whole body ChE activity and total length (7.2-17.9 mm) for larval walleye, but a negative correlation between brain ChE activity and total length (59-164 mm) for juvenile walleye (r = 0.75). Because size, age, and development may affect ChE activity, fish of similar size should be used when evaluating the effects of ChE inhibitors. If fish of similar size are not available, it is recommended that relations between size, age, and development be understood so estimates of variation in ChE activity can be made.

B7 family molecules: novel immunomodulators at the maternal-fetal interface

The placenta utilizes both active and passive mechanisms to evade rejection by the maternal immune system. Recently, the mRNA for two newly cloned members of the B7 family of immunomodulatory cell-associated proteins have been identified in the human term placenta. In this article, we review the current knowledge of the B7 family member B7-H1, and discuss how it may participate in modulation of the maternal immune system at the maternal-fetal interface. B7-H1 has been found to possess immunostimulatory or immunoinhibitory properties, and immunohistological examination of first trimester and term placenta has revealed that this protein is abundant in the placenta. B7-H1 is highly expressed by both the syncytiotrophoblast and extravillous cytotrophoblast, both of which lie in direct contact with maternal blood and tissue. Further, treatment of the choriocarcinoma cell line, JEG-3, with recombinant human interferon (IFN)-gamma resulted in a dose-dependent increase in the abundance of the message for B7-H1, suggesting that IFN-gamma could regulate expression of B7-H1 by the trophoblast. These studies document that the positioning of B7-H1 at the maternal-fetal interface is such that it could participate in suppression of activated maternal leukocytes.

Death-inducing tumour necrosis factor (TNF) superfamily ligands and receptors are transcribed in human placentae, cytotrophoblasts, placental macrophages and placental cell lines

Human placentae and two of the cell types in placentae (cytotrophoblasts and macrophages) were examined by RT-PCR for transcripts of the eight TNF superfamily ligands known to induce death of activated immune cells, tumour cells, and virus-infected cells (TNFalpha, LT alpha, LT beta, FasL, TRAIL, TWEAK, LIGHT, 4-1BBL). Transcripts for all ligands were detected in term placenta but LT alpha and 4-1BBL were not detected in first trimester placenta. Although term cytotrophoblasts contained mRNAs specific for TNF alpha, LT alpha, TWEAK, and 4-1BBL, messages encoding LT beta, FasL, TRAIL, and LIGHT were absent. In term placental macrophages, messages for all ligands except 4-1BBL were present. Transcripts for the 14 receptors to which the ligands bind, six of which contain death-domains (TNFR1, Fas, DR3, DR4, DR5, DR6), were also identified using RT-PCR. Term and first trimester placentae contained transcripts for all receptors except 4-1BB. Although term cytotrophoblasts lacked receptor mRNA encoding 4-1BB and OPG, term placental macrophages lacked DcR1 and OPG. Detection of nearly all the death-inducing TNF superfamily ligands and their receptors in human placentae implies that these powerful cytokines contribute to programmed or activated cell death in this organ.

TRAIL (Apo-2L) and TRAIL Receptors in Human Placentas: Implications for Immune Privilege

Mechanisms accounting for protection of the fetal semiallograft from maternal immune cells remain incompletely understood. In other contexts, interactions between TRAIL (TNF-related apoptosis-inducing ligand/Apo-2L) and its receptors kill activated lymphocytes. The purpose of this study was therefore to investigate the potential of the TRAIL/TRAIL-R system to protect the placenta against immune cell attack. Analysis by Northern blotting demonstrated mRNAs encoding TRAIL as well as the four TRAIL receptors (DR4, DR5, DcR1/TRID, DcR2/TRUNDD) in human placentas. Immunohistochemical experiments demonstrated that TRAIL protein is prominent in syncytiotrophoblast, an uninterrupted placental cell layer that is continuously exposed to maternal blood, as well as in macrophage-like placental mesenchymal cells (Hofbauer cells). Studies on cell lines representing trophoblasts (Jar, JEG-3 cells) and macrophages (U937, THP-1 cells) showed that both lineages contained TRAIL mRNA and that steady state levels of transcripts were increased 2- to 11-fold by IFN-γ. By contrast, cell lineage-specific differences were observed in expression of the TRAIL-R genes. Although all four lines contained mRNA encoding the apoptosis-inducing DR5 receptor, only trophoblast cells contained mRNA encoding the DcR1 decoy receptor and only macrophages contained DcR2 decoy receptor transcripts. DR4 mRNA was present only in THP-1 cells and was the only TRAIL-R transcript increased by IFN-γ. Cytotoxicity assays revealed that the two trophoblast cell lines were resistant, whereas the two macrophage lines were partially susceptible to killing by rTRAIL. Collectively, the results are consistent with a role for the TRAIL/TRAIL-R system in the establishment of placental immune privilege.

TRAIL (Apo-2L) and TRAIL receptors in human placentas: implications for immune privilege

Mechanisms accounting for protection of the fetal semiallograft from maternal immune cells remain incompletely understood. In other contexts, interactions between TRAIL (TNF-related apoptosis-inducing ligand/Apo-2L) and its receptors kill activated lymphocytes. The purpose of this study was therefore to investigate the potential of the TRAIL/TRAIL-R system to protect the placenta against immune cell attack. Analysis by Northern blotting demonstrated mRNAs encoding TRAIL as well as the four TRAIL receptors (DR4, DR5, DcR1/TRID, DcR2/TRUNDD) in human placentas. Immunohistochemical experiments demonstrated that TRAIL protein is prominent in syncytiotrophoblast, an uninterrupted placental cell layer that is continuously exposed to maternal blood, as well as in macrophage-like placental mesenchymal cells (Hofbauer cells). Studies on cell lines representing trophoblasts (Jar, JEG-3 cells) and macrophages (U937, THP-1 cells) showed that both lineages contained TRAIL mRNA and that steady state levels of transcripts were increased 2- to 11-fold by IFN-gamma. By contrast, cell lineage-specific differences were observed in expression of the TRAIL-R genes. Although all four lines contained mRNA encoding the apoptosis-inducing DR5 receptor, only trophoblast cells contained mRNA encoding the DcR1 decoy receptor and only macrophages contained DcR2 decoy receptor transcripts. DR4 mRNA was present only in THP-1 cells and was the only TRAIL-R transcript increased by IFN-gamma. Cytotoxicity assays revealed that the two trophoblast cell lines were resistant, whereas the two macrophage lines were partially susceptible to killing by rTRAIL. Collectively, the results are consistent with a role for the TRAIL/TRAIL-R system in the establishment of placental immune privilege.

Trophoblastic cell lines generated from tumour necrosis factor receptor-deficient mice reveal specific functions for the two tumour necrosis factor receptors

In mice and humans, expression of the tumour necrosis factor receptor-1 (TNF-R1) gene in placental trophoblast cells is constitutive whereas expression of the TNF-R2 gene is developmentally programmed. In order to study the individual functions of TNF-R1 and -R2 in this lineage, cell lines were generated from placental explants of homozygous matings of gestation day 10 outbred mice (Swiss-Webster), TNF-R1-deficient (TNF-R1-/-) and TNF-R2-/- transgenic mice as well as the background strain for the TNF-R2-/- mice (WT, C57BL/6x129). All of the cells exhibited trophoblast markers; they contained cytokeratin intermediate filaments, expressed alkaline phosphatase activity and displayed transferrin receptors, but were negative for vimentin filaments and the macrophage marker, F4/80. Analysis of DNA by polymerase chain reaction demonstrated the expected TNF-R genotype in each line. In experiments testing the effects of recombinant mouse TNF-alpha (rmTNF-alpha) on viability and proliferation of the cell lines, rmTNF-alpha modestly but dose-dependently inhibited the growth of WT and TNF-R2-/- cells while having no effect on TNF-R1-/- cells. Actinomycin D-treated WT and, to a lesser extent, TNF-R2-/- cells, were more sensitive to growth inhibition than untreated cells whereas TNF-R1-/- cell responses remained unchanged. These data indicated that rmTNF-alpha inhibits growth of trophoblastic cells through TNF-R1 and that newly synthesized protein(s) provide partial protection against toxicity. In contrast to the receptor species-specific effects on cell growth exerted by rmTNF-alpha, both TNF-R mediated inhibition of alkaline phosphatase activity. Collectively, the observations support the postulate that receptor expression is the key factor which determines the nature and extent of TNF-alpha effects on trophoblast cell growth and function.

The mouse macrophage activation-associated marker protein, p71/73, is an inducible prostaglandin endoperoxide synthase (cyclooxygenase)

The inducible protein p71/73 marks the response of mouse macrophages to one of several stimuli (e.g., bacterial lipopolysaccharide or poly I:C) that trigger the expression of cytolytic activity when these cells have previously been primed for tumor cell killing by interferon-gamma (IFN-gamma). The results reported here identify this marker protein as the inducible prostaglandin endoperoxide synthase (PES), TIS10/PES-2. Identification was based on four findings: (1) p71/73, like the TIS10/PES-2 protein, was associated with cellular membranes; (2) the sequence of amino acids in the NH2 terminus of both p71 and p73 was 96% identical to the predicted NH2-terminal sequence of the TIS10/PES-2 protein; (3) a polyclonal antiserum raised against the COOH-terminal region of the TIS10/PES-2 gene product recognized p71/73 in immunoblots; and (4) dexamethasone, which blocks induction of TIS10/PES-2 expression, inhibited the induction of both p71/73 synthesis and tumoricidal activity in macrophage. Several regulatory roles for this protein in the activation process are possible.

Activation-associated marker proteins: peptide mapping and their expression in macrophage cell lines

The activation-associated markers, p47b and p71/73, have been recognized as minor proteins in peritoneal and bone marrow culture-derived macrophages activated for tumor cell killing. Proteins with identical characteristics of migration on 2-dimensional gels and comparable Cleveland peptide maps are described here in macrophage cell lines that could be activated for tumor cell killing (J774A.1, RAW 264, UNC-2). Macrophage cell lines that could not be activated (P388D1 and PU5-1.8) did not express the markers. The expression of these markers in activatable macrophage cell lines strengthens their association with the activation process and provides a bulk source of the proteins for purification studies.

Loss of 4.5S RNA induces the heat shock response and lambda prophage in Escherichia coli

During depletion of 4.5S RNA, cells of Escherichia coli displayed a heat shock response that was simultaneous with the first detectable effect on ribosome function and before major effects on cell growth. Either 4.5S RNA is involved directly in regulating the heat shock response, or this particular impairment of protein synthesis uniquely induces the heat shock response. Several hours later, lambda prophage was induced and the cells lysed.

Levels of DNA topoisomerases, single-stranded-DNA-binding protein, and DNA polymerase I in rho+ and rho-15 strains of Escherichia coli

The Escherichia coli rho-15 mutant, which is highly defective in transcription termination, was examined to see whether its reduced DNA superhelicity could be explained by altered expression of proteins that may affect DNA structure. Levels of DNA gyrase and topoisomerase I were normal; levels of single-stranded-DNA-binding protein, DNA polymerase I, and a protein tentatively identified as Lon were significantly altered.

Genomically linked cellular protein databases derived from two-dimensional polyacrylamide gel electrophoresis

In its most useful form a cellular protein database should be genomically based, because it is the genome which determines both the total number of proteins a cell can make and the particular ones that will be made under any given condition. Such a database should trace each protein back to its structural gene, and should account for every structural gene of a cell. Recent advances in molecular biology greatly facilitate the construction of such gene-protein databases. The mapping of genes of unidentified proteins resolved from total cell extracts on two-dimensional gels can now be accomplished by largely biochemical methods, without the necessity of isolating mutants or performing genetic crosses. Other techniques permit one to search gels for the product of any newly discovered gene (or open reading frame) suspected of encoding a protein. Consequently, gene-protein indices can be built independently and simultaneously from either direction--deducing the genetic map from the protein pattern, or finding the protein pattern from information encoded in the genome. A database of this sort is being constructed for the bacterium, Escherichia coli. Given the current pace of DNA nucleotide sequencing, the development of total gene-protein indices for a variety of cells can be anticipated in the near future.