Abstract PD02-03: Regulation of Mammary Stem Cell Population with Dietary Intake of Soy Protein Isolate Reveals Novel Mechanisms for Diet-Mediated Control of Mammary Tumorigenesis

Breast cancer risk is highly modified by environmental factors including diet. Previously, we showed that dietary intake of soy protein isolate (SPI) decreased mammary tumor incidence and increased mammary tumor latency in rats relative to those fed a control casein (CAS) diet, when exposed to the chemical carcinogen NMU. Mammary tumor preventive effects by SPI were associated with up-regulation of the tumor suppressor PTEN and down-regulation of the oncogenic Wnt-signaling components in mammary epithelial cells (MECs) leading to enhanced differentiation. Given that breast cancer is considered to be initiated by stem cells (SCs) with tumorigenic potential, termed cancer stem cells (CSCs), and mammary over-expression of Wnt-1 in mice causes spontaneous breast tumors due to the expansion of mammary CSCs, we hypothesized that diet may alter the mammary SC population to effect mammary tumor prevention. Here, we investigated SPI effects relative to CAS, on mammary tumor development in MMTV-Wnt 1-Transgenic (Tg) female mice and on the mammary SC population in virgin wildtype (WT) and pre-neoplastic Tg female mice. Tumor incidence at 8 months of age of Tg mice fed SPI (n=30) post-weaning was lower than in those fed CAS (48.3% vs.73.5%; P<0.05) (n=34). Interestingly, tumor latency in SPI-fed Tg mice was shorter than for the CAS-fed group (4.65 vs. 5.88 months; P<0.05). Tumor weight and growth rate was similar for the diet groups. To evaluate SPI effects relative to CAS, on mammary SC population, epithelial cells from mammary tissues were isolated from WT (PND 100) and Tg (PND75) mice. The percentage of mammary SCs was quantified by fluorescence activated cell sorting analysis of MECs based on their expression of mouse mammary SC markers (CD29 and CD24) within the Lineage negative (Lin-) population (CD45-, TER119-, CD31-). The Lin-CD29hiCD24hi subpopulation in MECs was decreased by 50% in Tg mice fed SPI post-weaning relative to those fed CAS, decreasing the likelihood of mutations that convert normal to cancer SC and could explain the protective effects of SPI on tumor incidence. Interestingly, the SC population was expanded by 2-fold in MECs of WT mice fed SPI relative to the CAS group, which could be beneficial for mammary gland development and tissue homeostasis. Our findings provide the first report of dietary effects on the SC population in MECs in vivo. The dichotomy of SPI effects on tumor outcome in mammary tissues with dysregulated Wnt signaling maybe related to the loss of the complex regulatory grid between PTEN and Wnt/β-catenin pathways, both of which control stem cell fate. The possibility that diet can influence tumor progression at the level of the SC population suggests the important contribution of nutrition to the etiology of breast cancer and to the early management of breast health. Supported by USDA-ARS and Department of Defense Breast Cancer Research Program.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD02-03.

Primary stenting versus balloon angioplasty in occluded coronary arteries: the Total Occlusion Study of Canada (TOSCA)

BACKGROUND

Balloon angioplasty (PTCA) of occluded coronary arteries is limited by high rates of restenosis and reocclusion. Although stenting improves results in anatomically simple occlusions, its effect on patency and clinical outcome in a broadly selected population with occluded coronary arteries is unknown.

METHODS AND RESULTS

Eighteen centers randomized 410 patients with nonacute native coronary occlusions to PTCA or primary stenting with the heparin-coated Palmaz-Schatz stent. The primary end point, failure of sustained patency, was determined at 6-month angiography. Repeat target-vessel revascularization, adverse cardiovascular events, and angiographic restenosis (>50% diameter stenosis) constituted secondary end points. Sixty percent of patients had occlusions of >6 weeks' duration, baseline flow was TIMI grade 0 in 64%, and median treated segment length was 30.5 mm. With 95.6% angiographic follow-up, primary stenting resulted in a 44% reduction in failed patency (10.9% versus 19.5%, P=0.024) and a 45% reduction in clinically driven target-vessel revascularization at 6 months (15.4% versus 8.4%, P=0.03). The incidence of adverse cardiovascular events was similar for both strategies (PTCA, 23.6%; stent, 23.3%; P=NS). Stenting resulted in a larger mean 6-month minimum lumen dimension (1.48 versus 1.23 mm, P<0.01) and a reduced binary restenosis rate (55% versus 70%, P<0.01).

CONCLUSIONS

Primary stenting of broadly selected nonacute coronary occlusions is superior to PTCA alone, improving late patency and reducing restenosis and target-vessel revascularization.

Peri-operative hypoxaemia in children undergoing application of a plaster jacket for scoliosis

Twenty children (six female), median age 24 months (range 12-156) who presented for application of a plaster jacket for scoliosis were studied pre-operatively with pulse oximetry overnight and on the first postoperative night. Pre-operatively the median (range) arterial oxygen saturation was 97 (95-98)%, although eight children had short episodes of desaturation to < 90%. Postoperatively the median saturation was unchanged, and nine children had short episodes of desaturation. Neither the presence of episodes of desaturation pre-operatively, nor the median or lowest saturation recorded were predictors of postoperative median saturation or the presence of episodes of desaturation. Despite the presumed reduction in chest wall compliance, the application of a plaster jacket for scoliosis in these young children was not associated with a significant change in their oxygenation.

Short-term changes in tonic accommodation

Experiments were performed to determine the diurnal variation of, as well as the influence of total darkness on, tonic accommodation. In general, under both conditions trend analysis showed that variations in tonic accommodation over time were either nonsystematic in nature or could be best described by a simple linear function. Given the relatively small range of mean tonic accommodation values over time (0.5 to 1.1 D), the results demonstrate the robustness and stability of tonic accommodation under naturally occurring viewing conditions during the course of a day. In contrast, during the 2-hr period in total darkness, tonic accommodation exhibited a three-fold increase in mean range (0.6 to 2.5 D) as well as a significant increasing linear trend in some subjects, suggesting less stability of tonic accommodation in the absence of visual stimuli.

In vitro detection of heparin-induced humoral antiplatelet activity

We investigated the etiology of thrombocytopenia, with or without platelet thrombi, occurring while patients are receiving parenteral heparin. We used two in vitro methods to detect possible humoral factors in the sera of patients who became thrombocytopenic while receiving heparin. In the presence of heparin, four of four such patients' serum caused platelet aggregation. Only serum from the patient most severely affected clinically caused release of platelet factor 3 (PF3). All control sera gave negative results by both methods. We propose that platelet aggregation studies may be a sensitive and reliable method of confirming that thrombocytopenia occurring during heparin therapy is due to a humoral factor requiring the presence of heparin.

Hand injuries: incidence and epidemiology in an emergency service

During a four-month period, 1,164 patients presented to the surgical section of our Emergency Services (ES) with chief complaints involving the hand. Patient records were analyzed for several variables including demographics, diagnosis and therapeutic procedures. Lacerations were the most frequent injury, 61.5% (n=716) with deep structure injuries present in 6.1% (n=44). Of deep structure injuries, 36.4% were tendon lacerations, 27.2% were nerve injuries, and 36.4% were compound fractures. "Bites" accounted for 5.2% (37) of all lacerations, eight of which were human bites. Fractures were the second most frequent injury, (11.4%) and involved 143 separate bones. Infections were present in 7%; over half were paronychias. There were 42 (3.6%) thermal injuries.

Locomotion of bluefish

1. Pressure previously measured on the body surface of swimming bluefish were resolved into their backward vectorial components to allow calculation of profile drag. It was 0.18 kg at a speed of 1.8 m/sec. Tangential drag was calculated as if for a thin plate of an area equal to that of the fish. It was 0.08 kg at 1.8 m/sec. Net drag, 0.26 kg, was the sum of profile and tangential drag. 2. Thrust and drag also were calculated from the changes of acceleration measured during steady swimming, assuming that thrust took place only during the acceleration phase, whereas drag occurred during both acceleration and deceleration. This drag was 0.08 kg at a speed of 1.1 m/sec. It is compatible with the drag of 0.26 at 1.8 m/sec calculated from profile and tangential drag provided drag varies as the square of velocity. 3. The force required to produced maximal acceleration was measured during a scare. It was calculated to be 6.9 kg at a peak acceleration of 3 g. 4. The compression strength of th vertebrae was found to be approximately 20 kg per cm2, or roughly three times the force encountered during maximal acceleration. This safety factor of 3 would be reduced when the back was curved, or if opposing groups of muscles were under tension. 5. The finding that a bluefish can accelerate at 3 g and that the vertebral column is strongg enough to withstand this force indicates that the muscles and body structure of a bluefish would be able to withstand the force of gravity if the fish were otherwise equipped for terrestrial life. This fish may have evolved these strengths simultaneously with land animals. It is speculated that other fish may have evolved some degree of strength to overcome inertia and drag during aquatic locomotion, and this evolution may have been a prelude to terrestrial locomotion.

Pressure Distribution on the Body Surface of Swimming Fish

1. Pressures on the body surface of bluefish, swimming at 0-6 m.p.h., compared to lateral pressure, were recorded using strain-gauge manometers.

2. While in motion, the front of the fish is subject to a head-on pressure exactly equal to that calculated using the Pitot equation. In salt water, this pressure, in cm H2O, is equal to the speed, in m.p.h., divided by 0.98, all squared.

3. On the widest diameter the pressure is negative while swimming. This is attributable to the Bernoulli effect.

4. Pressure on the base of the tail is still negative, but not so negative as on the shoulder, in live swimming fish. The body and tail motion seem to draw water away from the peduncle of the tail, thereby diminishing turbulence.

5. In a dead fish the pressure at the base of the tail is positive, suggesting the possibility of boundary-layer separation and increased drag in dead fish towed through water.

6. The hydrodynamic pressures in fish swimming are often as great as the hydrostatic pressures encountered in animals of equal length subjected to gravity. We conclude that body defences against hydrodynamic pressure would also be useful against gravitational hydrostatic pressure.

7. Body structures which appear to resist hydrodynamic pressures in water and hydrostatic pressures on land are the skull, the vertebral column, and the circulatory system.

8. Transition from aquatic to terrestrial life may have been facilitated by adaptation to the pressures encountered on the body surface while swimming.