Circulating humanin levels are associated with preserved coronary endothelial function

Humanin is a small endogenous antiapoptotic peptide, originally identified as protective against Alzheimer's disease, but subsequently also found on human endothelium as well as carotid artery plaques. Endothelial dysfunction is a precursor to the development of atherosclerotic plaques, which are characterized by a highly proinflammatory, reactive oxygen species, and apoptotic milieu. Previous animal studies demonstrated that humanin administration may improve endothelial function. Thus the aim of this study was to test the hypothesis that patients with coronary endothelial dysfunction have reduced systemic levels of humanin. Forty patients undergoing coronary angiography and endothelial function testing were included and subsequently divided into two groups based on coronary blood flow (CBF) response to intracoronary acetylcholine (normal ≥ 50% increase from baseline, n = 20 each). Aortic plasma samples were obtained at the time of catheterization for the analysis of humanin levels and traditional biomarkers of atherosclerosis including C-reactive protein, Lp-Pla(2), and homocysteine. Baseline characteristics were similar in both groups. Patients with coronary endothelial dysfunction (change in CBF = -33 ± 25%) had significantly lower humanin levels (1.3 ± 1.1 vs. 2.2 ± 1.5 ng/ml, P = 0.03) compared with those with normal coronary endothelial function (change in CBF = 194 ± 157%). There was a significant and positive correlation between improved CBF and humanin levels (P = 0.0091) not seen with changes in coronary flow reserve (P = 0.76). C-reactive protein, Lp-Pla(2), and homocysteine were not associated with humanin levels. Thus we observed that preserved human coronary endothelial function is uniquely associated with higher systemic humanin levels, introducing a potential diagnostic and/or therapeutic target for patients with coronary endothelial function.

Abstract P1-09-04: Down-regulation of trefoil protein 1(TFF1) in normal breast tissue of postmenopausal women at increased risk for breast cancer on exemestane

Background: Aromatase inhibitors (AI) are effective for breast cancer risk reduction in postmenopausal women. TFF1, also known as pS2, is an estrogen response gene present in normal mammary tissue with increased expression in estrogen receptor positive breast cancer. Previous studies have demonstrated down-regulation of TFF1 and Ki-67, a marker of proliferation, in postmenopausal women with locally advanced breast cancer who receive neoadjuvant AIs. TFF1 and proliferating cell nuclear antigen (PCNA) may serve as biomarkers of effect of AIs in women at increased risk for breast cancer.

Methods: We conducted a single-arm phase II trial of exemestane in women at increased risk for breast cancer and examined the impact on TFF1 and PCNA. Postmenopausal women at increased risk for invasive breast cancer by clinical or histological criteria received 25mg of exemestane daily for 2 years. Subjects were required to have stopped any hormonal medication ≥ 3 months prior to enrollment. Image guided breast biopsies targeting dense breast tissue were performed at baseline and at 12 months. Core specimens were obtained under local anesthesia at each time point from the same area of the breast. One core biopsy sample was formalin-fixed, paraffin-embedded and examined for pathologic abnormalities, as well as TFF1 and PCNA. TFF1 was assessed by intensity of stain (0 to 3+) and percent of cells with any staining; PCNA was assessed by percent of cells staining within the tissue section. The pathologist (B.K.) was blinded to the time of biopsy. Change in intensity and % positive cells were evaluated by paired t-test.

Results: Thirty four subjects underwent both baseline & 12 month breast biopsies. Eight biopsies at baseline and 5 biopsies at 12 months did not contain any ductal or lobular tissue and were not analyzed. Twenty-two subjects had evaluable breast tissue at both time points for TFF1 analysis and 23 subjects for PCNA analysis. No high risk lesions or invasive cancers were identified. Of the baseline specimens, 95.5% were positive for TFF1: 59.1% (13 of 22) were scored as 3+(intense), 31.8% (7 of 22) were 2+(moderate) and 4.5% (1 of 22) were 1+(low). Percent of cells staining for TFF1 ranged from 0 to 20% (median = 1%). After 1 year on exemestane TFF1 intensity decreased in 17 subjects (77.3%), 4 had no change and 1 increased. Mean TFF1 change was −1.32 (95% CI −1.87 to −0.76; p < 0.001). The change in % positive cells for PCNA ranged from −15 to +30% (median = 0%).

Discussion: Assessing tissue biomarkers with repeat core needle biopsies in a phase II prevention trial in high risk women is feasible. Since prevention agents are not universally protective, determining biomarkers of effect may allow tailored therapy. TFF1 is a biologically plausible biomarker of AI activity that was down-regulated in 77% of breast tissue following exemestane therapy. This is the first study to evaluate this tissue marker in the prevention setting. Further study is needed to correlate with other biomarkers of interest, e.g. change in mammographic density, serum hormone levels and clinical outcomes.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-09-04.

Participation in high-impact sports predicts bone mineral density in senior olympic athletes

Background:

Loss of bone mineral density (BMD) and resultant fractures increase with age in both sexes. Participation in resistance or high-impact sports is a known contributor to bone health in young athletes; however, little is known about the effect of participation in impact sports on bone density as people age.

Hypothesis:

To test the hypothesis that high-impact sport participation will predict BMD in senior athletes, this study evaluated 560 athletes during the 2005 National Senior Games (the Senior Olympics).

Study Design:

Cross-sectional methods. The athletes completed a detailed health history questionnaire and underwent calcaneal quantitative ultrasound to measure BMD. Athletes were classified as participating in high impact sports (basketball, road race [running], track and field, triathalon, and volleyball) or non-high-impact sports. Stepwise linear regression was used to determine the influence of high-impact sports on BMD.

Results:

On average, participants were 65.9 years old (range, 50 to 93). There were 298 women (53.2%) and 289 men (51.6%) who participated in high-impact sports. Average body mass index was 25.6 ± 3.9. The quantitative ultrasound-generated T scores, a quantitative measure of BMD, averaged 0.4 ± 1.3 and −0.1 ± 1.4 for the high-impact and non-high-impact groups, respectively. After age, sex, obesity, and use of osteoporosis medication were controlled, participation in high-impact sports was a significant predictor of BMD (R² change 3.2%, P < .001).

Conclusions:

This study represents the largest sample of BMD data in senior athletes to date. Senior participation in high-impact sports positively influenced bone health, even in the oldest athletes.

Clinical Relevance:

These data imply that high-impact exercise is a vital tool to maintain healthy BMD with active aging.

SU-E-J-67: A Potential New Technique to Measure Respiratory Tidal Volume Using Optical Surface Imaging: A Geometric and Deformable Phantom Study

PURPOSE

To develop a new method for accurate measurement of dynamic respiratory tidal volume, we investigate the feasibility of measuring torso volume change using optical surface imaging (OSI).

METHODS

Based on a validated volume conservation theory, the tidal volume is equal to the volume change of the torso during quiet respiration (Li et al, PMB, 54:1693, 2009). A clinical OSI system was employed to acquire surface images of seven geometric phantoms and two 'deformable' torso phantoms. The mesh surface images were converted into contours for volume calculation using a treatment planning system. For geometric phantoms, their volumes under the incomplete surface images were calculated with aid of their symmetry. The results were compared with theoretical calculation and water containment experiments. For deformable torso phantoms, we created volume-controlled deformation stages by placing deformable PlayDoh (DPD) materials on top of rigid Rando/Thorax phantoms, mimicking respiration-induced torso surface elevation and volume change. The volume difference under the surfaces with and without the DPD padding was calculated with aid of a common posterior line to enclose the region of interest. Three different volumes of DPD padding (>500cc) were mounted on the torso phantoms and CT scanned for volume measurements.

RESULTS

For geometric phantoms, the OSI measured volume had accuracy (±1s) of 0.0%±1.6% (vs. geometric volume calculation) and 0.6%±3.8% (vs. water containment experiment). For deformable torso phantoms, the volume change was measured using OSI with an accuracy of 1.5%±2.5% against the measured volume using CT imaging. Linear regression showed a one-to-one relationship between the OSI volumes and CT volumes with a slope of 1.003 (r2=0.999).

CONCLUSIONS

The optical surface imaging system can accurately measure the volume of geometric phantoms and the volume change of deformable torso phantoms. The accuracy is about 3% against standard volume measurement methods. Further study on human subjects is under investigation. Memorial Sloan-Kettering Cancer Center has a reserach agreement with Vision RT, Inc.

Contribution of an aging environment towards a proinflammatory tumor-like milieu (54.4)

Chronic inflammation associated with aging is termed inflamm-aging. It manifests as a rise in many proinflammatory mediators and contributes to a decline in immune function. Unregulated inflammasome activation initiates an inappropriate inflammatory response. It is particularly imperative to understand inflammasome dysregulation in the elderly (&gt;65 yrs), since it is a likely basis of immune dysfunction. Analyses of freshly isolated memory CD4+ and CD8+ splenic T cells demonstrated that even without further activation, inflammasome genes were already significantly up-regulated in old mice compared to young, including factors critical to myeloid-derived suppressor cell (MDSC) expansion including S100a8, S100a9, IL-1β, IL-13 and IL-6. A corresponding 2-3 fold increase in CD11b+Gr1+cells was observed in the spleens of old naïve mice compared to young. Importantly, cells with the CD11b+Gr1+ phenotype from old mice, unlike young, were functionally MDSCs and suppressed T cell proliferation. Therefore, the immunosuppressive environment of the tumor-bearing host also appears to be operative in aging, even in the absence of tumor. We hypothesize that constituitive activation of inflammasome complex results in a chronic inflammatory state, altering immune responses in the elderly similarly to the tumor-bearing state. Preemptive reversal of inflammasome-induced MDSCs may enhance T cell immunosurveillance in the elderly, a population with a heightened susceptibility to malignancy.

P3-11-01: Effects of Exemestane Therapy on the Lipid Profile of Postmenopausal Women with an Elevated Risk of Developing Invasive Breast Cancer

Background: Aromatase inhibitors are effective for breast cancer prevention in postmenopausal women. In the recent MAP.3 study, exemestane significantly reduced invasive breast cancer in postmenopausal women with an elevated risk of developing breast cancer. At 35 months follow up there was no increase risk in cardiovascular events in this study; however, the effects of exemestane use on lipid profiles and cardiovascular health are still unclear.

Methods: We conducted a single-arm phase II trial of exemestane in women at increased risk for breast cancer and examined the impact of exemestane on lipid profiles. Postmenopausal women at high risk for invasive breast cancer (e.g., Gail Model risk ≥ 1.7, a history of lobular neoplasia, atypical ductal hyperplasia, DCIS, or stage I/II breast cancer, or BRCA 1/2 mutation) were given exemestane (25 mg orally daily) for 2 years. Fasting serum total cholesterol, HDL, LDL, triglycerides, and homocysteine were collected at baseline, 3, 12, and 24 months after initiation of exemestane therapy. Apolipoprotein A and B were collected at baseline, 3 and 12 months. Wilcoxon sign ranked test was used to analyze if changes from baseline values differed from zero. The Hochberg p-value adjustment was used to account for multiple hypothesis tests.

Results: Of the 42 women enrolled in the study, 6 dropped out prior to completing 1 year and 1 dropped out prior to completing 2 years of exemestane therapy. Thirty-one women have completed 2 years of exemestane therapy and the remaining 4 are expected to complete 2 years of therapy by January 2012. On average, participants were 58.5 years old, mostly Caucasian (n = 37; 84.1%), and had a BMI of 29.2 kg/m2. A majority (n = 19) of participants were on lipid-lowering medications (14 were taking a statin) or taking fish oil supplements (n =5) prior to starting on the trial and 1 was started on a statin approximately 10 months after starting the trial. There were no significant differences in mean lipid values for each of the 4 assessment points or in the mean change from baseline at 3, 12, and 24 months between patients who were taking lipid-lowering medications and those were not. In unadjusted analyses, change in HDL from baseline was significantly different from zero and decreased from baseline at 3, 12 and 24 months (−8.0 mg/dL, −8.5 mg/dL, and −9.9 mg/dL; All p-values ≤ .001 before and after applying the Hochberg adjustment). Total cholesterol also significantly decreased from baseline at 3 months (−13.6 mg/dL, p = .002) but was no longer significant at 12 and 24 months (−9.6 mg/dL and −11.4 mg/dL, respectively; p-values = .07). The rest of the lipid panel did not significantly change during follow-up.

Discussion: In agreement with previous studies, we found that exemestane causes a significant decrease in HDL and total cholesterol, while leaving the rest of the lipid panel unchanged. Prior studies excluded patients on lipid-lowering medication; half of our participants were taking lipid-lowering medication. It is notable that both women off and on lipid-lowering medication had decreases in HDL. Additional studies are needed to elucidate long-term cardiovascular outcomes in this high risk but otherwise healthy population.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-11-01.