Hypoxia differentially regulates human nucleus pulposus and annulus fibrosus cell extracellular matrix production in 3D scaffolds

OBJECTIVE

We hypothesize that intervertebral disc (IVD) cells from distinct region respond differently to oxygen environment, and that IVD cells from patients with disc degeneration can benefit from hypoxia condition. Therefore, we aimed to determine the transcriptional response and extracellular matrix (ECM) production of nucleus pulposus (NP) and annulus fibrosus (AF) cells to different oxygen tension.

METHOD

Human NP and AF from degenerated IVD were seeded in 3D scaffolds and subjected to varying oxygen tension (2% and 20%) for 3 weeks. Changes in ECM were evaluated using quantitative real-time reverse transcriptase polymerase chain reaction, histological and immunohistological analyses.

RESULTS

Hypoxia significantly enhances NP cells phenotype, which resulted in greater production of sulfated glycosaminoglycan (GAG) and collagen type II within the constructs and the cells expressed higher levels of genes encoding NP ECM. A significantly stronger fluorescent signal for hypoxia-inducible factor (HIF-1α) as also found in the NP cells under the hypoxic than normoxic condition. However, there was little effect of hypoxia on the AF cells.

CONCLUSIONS

The NP and AF cells respond differently to hypoxia condition on the 3D scaffold, and hypoxia could enhance NP phenotype. When used in concert with appropriate scaffold material, human NP cells from degenerated disc could be regenerated for tissue engineering application.

Real-time manifestation of strongly coupled spin and charge order parameters in stripe-ordered La(1.75)Sr(0.25)NiO(4) nickelate crystals using time-resolved resonant x-ray diffraction

We investigate the order parameter dynamics of the stripe-ordered nickelate, La(1.75)Sr(0.25)NiO(4), using time-resolved resonant x-ray diffraction. In spite of distinct spin and charge energy scales, the two order parameters' amplitude dynamics are found to be linked together due to strong coupling. Additionally, the vector nature of the spin sector introduces a longer reorientation time scale which is absent in the charge sector. These findings demonstrate that the correlation linking the symmetry-broken states does not unbind during the nonequilibrium process, and the time scales are not necessarily associated with the characteristic energy scales of individual degrees of freedom.

Comparative analysis of lifestyle factors, screening test use, and clinicopathologic features in association with survival among Asian Americans with colorectal cancer

Background:

Colorectal cancer (CRC) diagnoses and disease-specific survival (DSS) vary between ethnic groups in the United States. However, few studies have assessed differences among Asian subgroups.

Methods:

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients with invasive CRC between 1988 and 2008. Differences in clinicopathologic features, and DSS rates were compared among Asian subgroups. The California Health Interview Survey was used to examine risk factors and screening patterns for CRC.

Results:

The study included 359 374 patients with 8.4% Asian. Patients in all Asian subgroups were younger (median: 68 years) at diagnosis than non-Hispanic white (NHW) patients (median: 72 years). Most Asian subgroups, except Hawaiians, had better DSS than NHW patients although Asian subgroups had more advanced disease than NHW. Indian/Pakistani patients had a higher 5-year DSS than other Asian subgroups. Obesity proportions were lower in Asian subgroups (<50.2%) than in NHW (59.8%). Vietnamese men and Korean women had the lowest proportions of CRC screening. Advance tumour stages were highly associated with worse DSS in each ethnicity group. High tumour grades were associated with worse DSS in NHW, Filipino, and Chinese. Older age at diagnosis was associated with worse DSS in most ethnicity groups except Hawaiian and Vietnamese.

Conclusion:

Disparities exist between Asians and NHW with CRC, and among various Asian subgroups. Differences in cancer clinicopathologic features, patients' behavioural habits, lifestyle, and screening patterns may explain some differences in CRC survival observed among ethnic groups.

Observation of temperature-induced crossover to an orbital-selective Mott phase in A(x)Fe(2-y)Se2 (A=K, Rb) superconductors

Using angle-resolved photoemission spectroscopy, we observe the low-temperature state of the A(x)Fe(2-y)Se(2) (A=K, Rb) superconductors to exhibit an orbital-dependent renormalization of the bands near the Fermi level-the d(xy) bands heavily renormalized compared to the d(xz)/d(yz) bands. Upon raising the temperature to above 150 K, the system evolves into a state in which the d(xy) bands have depleted spectral weight while the d(xz)/d(yz) bands remain metallic. Combined with theoretical calculations, our observations can be consistently understood as a temperature-induced crossover from a metallic state at low temperatures to an orbital-selective Mott phase at high temperatures. Moreover, the fact that the superconducting state of A(x)Fe(2-y)Se(2) is near the boundary of such an orbital-selective Mott phase constrains the system to have sufficiently strong on-site Coulomb interactions and Hund's coupling, highlighting the nontrivial role of electron correlation in this family of iron-based superconductors.

Measurement of coherent polarons in the strongly coupled antiferromagnetically ordered iron-chalcogenide Fe1.02Te using angle-resolved photoemission spectroscopy

The nature of metallicity and the level of electronic correlations in the antiferromagnetically ordered parent compounds are two important open issues for the iron-based superconductivity. We perform a temperature-dependent angle-resolved photoemission spectroscopy study of Fe(1.02)Te, the parent compound for iron chalcogenide superconductors. Deep in the antiferromagnetic state, the spectra exhibit a "peak-dip-hump" line shape associated with two clearly separate branches of dispersion, characteristics of polarons seen in manganites and lightly doped cuprates. As temperature increases towards the Néel temperature (T(N)), we observe a decreasing renormalization of the peak dispersion and a counterintuitive sharpening of the hump linewidth, suggestive of an intimate connection between the weakening electron-phonon (e-ph) coupling and antiferromagnetism. Our finding points to the highly correlated nature of the Fe(1.02)Te ground state featured by strong interactions among the charge, spin, and lattice and a good metallicity plausibly contributed by the coherent polaron motion.

Abstract P1-07-09: Estrogen receptor positivity: 10% or 1%?

Background. Guidelines by the American Society of Clinical Oncology and the College of American Pathologists recently recommended that estrogen receptor (ER) status should be considered positive if 1% of tumor cells demonstrate positive nuclear staining by immunohistochemistry. Historically, 10% nuclear staining defined ER-positive status and impacted decision-making regarding endocrine therapy. Currently, no optimal threshold exists for ER either by clinically validating patient outcomes in prospective clinical trials or independently validated from systematically collected archived specimens from randomized clinical trials. In this study, we examined patient, tumor and treatment differences among patients by ER status: ER-positive ≥10%, ER-positive 1–10% and ER negative (&lt;1%). We compared recurrence-free survival (RFS), disease-specific survival (DSS) and overall survival (OS) among patients with different ER staining categories and adjusted by clinical stage, adjuvant chemo and endocrine therapy.

Method. Patients with primary breast carcinoma treated at our center who had complete ER status from January 1990 to December 2011 were included in this study. Patients were excluded if they presented with recurrent or metastatic disease. For statistical analyses, patients who underwent surgery for breast cancer were separated into three groups: ER-positive ≥10%, ER-positive 1–10% and ER negative. Analyses comparing various clinical and pathologic characteristics among patients with different ER status were performed. Survival rates were calculated by the Kaplan-Meier method.

Result. Patients whose tumors were ER-positive 1–10% (2.7%) were younger (median age 53 Vs. 56 years, P &lt; 0.0001), more likely to have invasive ductal carcinoma histology with more advanced disease (clinical stage II/III 50.4% Vs. 37.3%, p &lt; 0.0001), and were more likely to receive neoadjuvant chemotherapy (40.9% vs. 25.6%, P &lt; 0.0001), adjuvant chemotherapy (45.5% vs. 31.2%, P &lt; 0.0001), and less likely to receive adjuvant endocrine therapy (19.5% vs. 78.6%, P &lt; 0.0001) compared to patients with ER-positive tumors ≥ 10%. They were also more likely to have HER-2-positive (29.1% vs. 13.4%, P &lt; 0.0001) and grade III disease (82.1% vs. 29.6%, P &lt; 0.0001). Compared to patients with ER negative, patients with ER-positive 1–10% had earlier stage disease (clinical stage II/III 50.4% Vs. 59.3%, p = 0.01), were less likely to receive neoadjuvant chemotherapy (40.9% vs. 48.2%, p = 0.02), and more likely to receive adjuvant endocrine therapy (19.5% vs. 12.6%, p = 0.002). At a median follow-up of 5.1 years, patients with ER-positive 1–10% had worse RFS, DFS and OS rates compared to patients with ER-positive tumors ≥ 10%. The RFS, DFS and OS rates between patients with ER-positive 1–10% and ER negative did not differ significantly. Patients with ER-positive 1–10% and negative still had worse RFS, DSS and OS rates compared to patients with ER-positive tumors ≥ 10% after adjusted by clinical stage, adjuvant chemo and endocrine therapy.

Conclusion. Patients whose tumors are ER-positive at 1–10% have clinical and pathologic characteristics different from those whose tumors are ER-positive ≥10%. Similar to patients whose tumors are ER negative, those with ER-positive disease at 1–10% do not appear to benefit from endocrine therapy.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-09.

MicroRNA-106b-25 cluster expression is associated with early disease recurrence and targets caspase-7 and focal adhesion in human prostate cancer

The miR-106b-25 microRNA (miRNA) cluster is a candidate oncogene in human prostate cancer. Here, we report that miRNAs encoded by miR-106b-25 are upregulated in both primary tumors and distant metastasis. Moreover, increased tumor miR-106b expression was associated with disease recurrence and the combination of high miR-106b and low CASP7 (caspase-7) expressions in primary tumors was an independent predictor of early disease recurrence (adjusted hazard ratio=4.1; 95% confidence interval: 1.6-12.3). To identify yet unknown oncogenic functions of miR-106b, we overexpressed it in LNCaP human prostate cancer cells to examine miR-106b-induced global expression changes among protein-coding genes. The approach revealed that CASP7 is a direct target of miR-106b, which was confirmed by western blot analysis and a 3'-untranslated region reporter assay. Moreover, selected phenotypes induced by miR-106b knockdown in DU145 human prostate cancer cells did not develop when both miR-106b and CASP7 expression were inhibited. Further analyses showed that CASP7 is downregulated in primary prostate tumors and metastatic lesions across multiple data sets and is by itself associated with disease recurrence and disease-specific survival. Using bioinformatics, we also observed that miR-106b-25 may specifically influence focal adhesion-related pathways. This observation was experimentally examined using miR-106b-25-transduced 22Rv1 human prostate cancer cells. After infection with a miR-106b-25 lentiviral expression construct, 22Rv1 cells showed increased adhesion to basement membrane- and bone matrix-related filaments and enhanced soft agar growth. In summary, miR-106b-25 was found to be associated with prostate cancer progression and disease outcome and may do so by altering apoptosis- and focal adhesion-related pathways.

Searching for non-B DNA-forming motifs using nBMST (non-B DNA motif search tool)

This unit describes basic protocols on using the non-B DNA Motif Search Tool (nBMST) to search for sequence motifs predicted to form alternative DNA conformations that differ from the canonical right-handed Watson-Crick double-helix, collectively known as non-B DNA, and on using the associated PolyBrowse, a GBrowse-based genomic browser. The nBMST is a Web-based resource that allows users to submit one or more DNA sequences to search for inverted repeats (cruciform DNA), mirror repeats (triplex DNA), direct/tandem repeats (slipped/hairpin structures), G4 motifs (tetraplex, G-quadruplex DNA), alternating purine-pyrimidine tracts (left-handed Z-DNA), and A-phased repeats (static bending). The nBMST is versatile, simple to use, does not require bioinformatics skills, and can be applied to any type of DNA sequences, including viral and bacterial genomes, up to an aggregate of 20 megabasepairs (Mbp).

Effect of surface chemistry on gene transfer efficiency mediated by surface-induced DNA-doped nanocomposites

Surface-induced biomineralization represents an effective way of immobilizing DNA molecules on biomaterial surfaces to introduce DNA into cells in contact with or at an approximate distance from the biomaterial surfaces. Previous studies have investigated how the composition of mineralizing solutions affects the composition and pH responsiveness of nanocomposites and thus gene transfer efficiency in different cell types. This study investigates how the functional groups of a biomaterial surface affect the induction and crystallographic properties of nanocomposites and thus the gene transfer efficiency. Self-assembled monolayers with different termini were used to control the functional groups of a surface. It is demonstrated that the induction of DNA-doped nanocomposites depends on the surface functional groups, which is consistent with previous studies. The crystallographic properties did not vary significantly with the functional groups. DNA-doped nanocomposites induced by different surface functional groups resulted in different cellular uptake of DNA and thus gene transfer efficiency. The differential cellular uptake may be attributed to the interactions between nanocomposites and functional groups. The weaker inducer resulted in higher cellular uptake, and thus higher gene transfer efficiency. Together with other previous studies, the current results suggest that surface-mediated gene transfer by DNA-doped nanocomposites can be modulated through both mineralizing solutions and surface chemistries.

MiR-1 and miR-200 inhibit EMT via Slug-dependent and tumorigenesis via Slug-independent mechanisms

Epithelial-mesenchymal transition (EMT) is a developmental program of signaling pathways that determine commitment to epithelial and mesenchymal phenotypes. In the prostate, EMT processes have been implicated in benign prostatic hyperplasia and prostate cancer progression. In a model of Pten- and TP53-null prostate adenocarcinoma that progresses via transforming growth factor β-induced EMT, mesenchymal transformation is characterized by plasticity, leading to various mesenchymal lineages and the production of bone. Here we show that SLUG is a major regulator of mesenchymal differentiation. As microRNAs (miRs) are pleiotropic regulators of differentiation and tumorigenesis, we evaluated miR expression associated with tumorigenesis and EMT. Mir-1 and miR-200 were reduced with progression of prostate adenocarcinoma, and we identify Slug as one of the phylogenetically conserved targets of these miRs. We demonstrate that SLUG is a direct repressor of miR-1 and miR-200 transcription. Thus, SLUG and miR-1/miR-200 act in a self-reinforcing regulatory loop, leading to amplification of EMT. Depletion of Slug inhibited EMT during tumorigenesis, whereas forced expression of miR-1 or miR-200 inhibited both EMT and tumorigenesis in human and mouse model systems. Various miR targets were analyzed, and our findings suggest that miR-1 has roles in regulating EMT and mesenchymal differentiation through Slug and functions in tumor-suppressive programs by regulating additional targets.

Femtosecond dynamics of the collinear-to-spiral antiferromagnetic phase transition in CuO

We report on the ultrafast dynamics of magnetic order in a single crystal of CuO at a temperature of 207 K in response to strong optical excitation using femtosecond resonant x-ray diffraction. In the experiment, a femtosecond laser pulse induces a sudden, nonequilibrium increase in magnetic disorder. After a short delay ranging from 400 fs to 2 ps, we observe changes in the relative intensity of the magnetic ordering diffraction peaks that indicate a shift from a collinear commensurate phase to a spiral incommensurate phase. These results indicate that the ultimate speed for this antiferromagnetic reorientation transition in CuO is limited by the long-wavelength magnetic excitation connecting the two phases.

P3-07-05: Nomogram Incorporating SLN Metastasis Size Provides the Most Accurate Prediction of Non-SLN Involvement in Breast Cancer Patients

Introduction: The finding of metastatic disease in the axillary nodes remains an important factor that guides adjuvant therapy decisions in breast cancer. The value of completion axillary lymph node dissection (ALND) may not be the same in all patients and determining the risk of non-SLN involvement can be a guide in surgical decision making. We recently developed a nomogram that incorporates the maximum SLN metastasis size to predict non-SLN axillary involvement (Mittendorf et al., Ann Surgery 2011,in press). The purpose of this study was to compare the accuracy of this nomogram to another widely used nomogram that does not include SLN metastasis size.

Methods: We queried a prospective breast cancer database for patients with clinically negative nodes undergoing sentinel node biopsy who did not receive neoadjuvant therapy. We identified 431 patients with invasive breast cancer treated from 1996 to 2007 who had a positive SLN and underwent completion ALND. We evaluated clinicopathologic data including histology, multifocality, nuclear grade, pathologic tumor size, number of SLNs recovered, number of positive SLNs, maximum SLN metastasis size, presence of extranodal extension, hormone receptor status, and presence of lymphovascular invasion. Data were entered into our nomogram and the nomogram that does not include SLN metastasis size. The accuracy of the 2 nomograms in predicting non-SLN axillary metastasis was compared in all patients and in subgroups of patients based on burden of disease in the SLN.

Results: For the entire cohort of 431 women with positive SLNs, our SLN size nomogram was more accurate in the detection of non-SLN disease (area under the receiver operating characteristic curve [AUC] 78.3% vs. 72.4%, p=0.01). Whether or not SLNs were subjected to frozen section did not influence the relative accuracies of the 2 nomograms. When patients were analyzed by burden of disease in the SLNs, our SLN size nomogram was more accurate in predicting non-SLN disease in patients with macrometastases in the SLN (AUC 77.3% vs. 70.3%, p=0.008). There was no significant difference in the accuracy of the 2 nomograms for patients with isolated tumor cells or micrometastases in the SLNs.

Conclusions: Our nomogram incorporating SLN metastasis size with other clinicopathologic factors is the most accurate predictor of the risk of non-SLN metastasis in patients with a positive SLN. The SLN size nomogram is highly accurate in women with macrometastases, who may benefit the most from completion ALND. Using a nomogram with SLN metastasis size can provide the most accurate information for patient counseling and surgical decision making.

A novel staging system for disease-specific survival in patients with breast cancer treated with surgery as the first intervention

92

Background: American Joint Committee on Cancer (AJCC) staging of breast cancer is used to determine prognosis, yet survival of patients within each stage shows wide variation and remains unpredictable. We hypothesized that differences in underlying biology might influence some of this variation and that the addition of biologic markers to current AJCC staging parameters would improve predictions of prognosis.

Methods: We identified an initial cohort of 3,728 patients at our center who underwent surgery as the first intervention between 1997 and 2006. We used a Cox proportional hazards model, with backward stepwise exclusion of factors and stratified on pathologic stage (PS), to test the added significance of modified Black’s nuclear grade (G), the presence of lymphovascular invasion (L), estrogen receptor status (E), progesterone receptor status (P), or combined ER and PR status (EP), or combined receptor subtype (ER+PR+HER2 [M]). We assigned values 0-2 to these disease-specific survival (DSS)–associated factors and then used different combinations to assess different staging systems. Surveillance Epidemiology and End Results (SEER) data was used as the external cohort (n=26,711) to validate the scoring system.

Results: Median follow-up time for the initial cohort was 6.5 years, and the 5-year DSS rate was 97.4%. Six different staging systems were used to predict 5-year patient outcomes: PS, PS+G, PS+GL, PS+EG, PS+GEP, and PS+GM. We compared 5-year DSS rates, Akaike’s information criterion (AIC) and Harrell’s concordance index (C-index) for each staging system. We found that the PS+GEP staging system was most precise with lowest AIC (1927.3) and had the highest C-index (0.80). The ability of the PS+GEP system to stratify outcomes was confirmed in the internal bootstrapping samples and the external validation cohort.

Conclusions: Our results validate a new staging system that incorporates tumor grade, ER and PR status into current AJCC staging for breast cancer. We recommend that biologic markers be incorporated into revised versions of the AJCC staging system for patients undergoing surgery as their first intervention.

Impact of chemotherapy timing on local-regional failures in patients with breast cancer undergoing breast-conserving therapy

82

Background: Debate continues as to whether BCT after neoadjuvant chemotherapy (chemo) can achieve long-term local control rates similar to those experienced by patients undergoing surgery first, especially in those presenting with large tumors. This study was performed to evaluate long-term results of BCT for patients undergoing surgery first versus chemotherapy.

Methods: 2,984 patients underwent BCT with whole breast irradiation from 1987 to 2005. Clinicopathologic and outcomes data were reviewed and comparisons made between surgery first and chemotherapy patients.

Results: 2,331 (78%) patients underwent surgery first; 653 (22%) received chemotherapy first. Overall, chemotherapy patients had more adverse clinicopathologic features (Table). 5 and 10-yr local-regional recurrence (LRR)-free survival rates were 97% (95% CI: 96%-98%) and 94% (93%-95%) for surgery first patients. Chemotherapy downstaged patients presenting with clinical stage II/III disease (608/653; 93%) allowing for BCT, and pathologic findings revealed stage II/III disease in only 305/653 (46%) (p<.001). 5 and 10-yr LRR-free survival rates were 93% (91%-95%) and 90% (87%-93%) after chemotherapy. After adjusting for clinical stage at presentation, there were no differences in LRR between surgery first and chemotherapy patients. On multivariate analysis, age<50, clinical stage III, grade 3, ER neg status, associated DCIS on final pathology, and close/positive margins were associated with LRR.

Conclusions: LRR after BCT is driven by biologic factors and not the timing of chemotherapy. Chemotherapy downstages a significant number of patients with stage II/III disease allowing appropriately selected patients to achieve high rates of local-regional control with BCT.

[Table: see text]

Abstract P4-10-14: Risk of Ipsilateral Breast Events in Patients with Ductal Carcinoma In Situ after Local Excision

Purpose

To determine the risk of ipsilateral breast events (IBE) in patients with ductal carcinoma in situ (DCIS) treated with local excision. Patients and Methods

We retrospectively identified 692 patients who had undergone local excision from 1968 through 2007 at our institution with a final diagnosis of DCIS. Factors evaluated included age, race, method of detection, menopausal status, bloody nipple discharge, histological type, final margin status, grade, status at last follow-up and recurrence information. An IBE was defined as the development of breast cancer of invasive histology or DCIS (but not lobular carcinoma in situ) in the treated breast.

Results

At a median follow-up of 6.1 years, 47 (6.8%) IBEs occurred in the 692 patients. Among 47 IBE, 23 (48.9%) were DCIS and 19 (40%) were invasive cancer and 5 (10.6%) were unknown type of IBE. Patients with IBE were younger (53 Vs 57, P=0.04). Whether patients had final positive margin (4 patients) had no influence on IBE. Use of a Cox proportional hazards model showed that patients with high grade tumors and those who did not receive adjuvant radiation therapy (XRT) were more likely to have an IBE (Hazard ratio: 4.1, 95% CI:1.3-13.4, P=0.019). The 5-year rate of ipsilateral breast events for patients with grade III DCIS who did not undergo adjuvant radiation therapy was significantly higher than all others: 15% vs. 4.6% compared to grade I/II with XRT, 15% vs. 10% compared to grade I/II without XRT, and 15% vs. 9.9% in grade III with XRT (P=0.017). Conclusions

Patients with low or intermediate grade DCIS have an acceptably low rate of ipsilateral breast events after local excision with adjuvant radiation therapy. Patients with high-grade lesions treated without irradiation have a rate of IBE of 15% at 6 years, suggesting that excision alone is inadequate treatment in this group. Further follow-up is necessary to document long-term results.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-10-14.

The survey of HIV/AIDS related knowledge, attitude and behaviour among migrant peasant workers in middle city in China

OBJECTIVES

To explore HIV/AIDS related knowledge, attitude and behaviour among migrant peasant workers in Changsha, which is a inland city in central China, and to provide evidence that educating this population may help to prevent the spread of HIV/AIDS in China.

METHODS

A total of 1782 migrant peasant workers participated in the study. A questionnaire was used to determine their knowledge of HIV/AIDS and related attitude and behaviour items.

RESULTS

The majority of the respondents had a rather low level of overall HIV/AIDS knowledge and its prevention, had what constituted risky behaviour in this regard and a generally low acceptance of HIV-infected persons. Furthermore, their behaviour and attitude were analysed with respect to their educational level, occupational class and score of HIV/AIDS related knowledge.

CONCLUSIONS

The results of this investigation will help healthcare professionals develop a sensitive and specific educational programme for migrant peasant workers. Educating this population will be a very important aspect of HIV/AIDS prevention in China.

Hypoxic neonatal pulmonary arterial myocytes are sensitized to ROS-generated 8-isoprostane

8-Isoprostane, a ROS-derived prostanoid that acts via the thromboxane receptor (TP), is implicated in neonatal pulmonary hypertension. The purpose of this study was to examine the effect of hypoxia on vascular smooth muscle ROS generation, 8-isoprostane activity, and TP binding. First-passage neonatal porcine pulmonary artery myocytes were exposed to 10% O(2) (hypoxic myocytes; HM) or 21% O(2) (normoxic myocytes) for 72 h. Hypoxia increased in vitro generation of ROS, superoxide, and 8-isoprostane. ROS generation was ablated by inhibition of mitochondrial complex III. SOD1 and 3 activities were increased, but SOD2 activity decreased by 45% in HM. 8-Isoprostane generation was driven by the addition of peroxide and nitric oxide; incubation with permeative PEG-SOD, but not PEG-catalase or impermeative SOD, attenuated hypoxia-induced 8-isoprostane generation. 8-Isoprostane affinity for TP was markedly increased in HM. Myocyte 8-isoprostane challenge caused TP internalization and calcium release only in HM; this was sensitive to TP blockade and was normalized by activation of adenylyl cyclase. We propose that hypoxia induces superoxide accumulation in pulmonary artery myocytes through inhibition of mitochondrial SOD2 activity, promoting peroxynitrite-induced generation of 8-isoprostane. 8-Isoprostane binds to sensitized TP receptors, causing receptor internalization and signaling to calcium release in hypoxic myocytes. 8-Isoprostane may be an important pulmonary vasoconstrictor during neonatal hypoxia.

Factors leading to the decision for contralateral prophylactic mastectomy in patients with breast cancer

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Background: Women with breast cancer have an increased risk of developing contralateral breast cancer in their lifetime. Thus increasing numbers of women have been electing to undergo contralateral prophylactic mastectomy (CPM) at the time of their initial breast cancer treatment. The objective of this study was to identify factors that determine the decision for CPM in patients at a major cancer center. Methods: 2,544 women with Stage 0-III unilateral primary breast cancer who underwent surgery to the breast at our institution from January 2000 to August 2006 were identified from a prospectively maintained database. Patient and tumor characteristics were evaluated and comparisons were made between patients who did or did not undergo CPM using logistic regression. Results: Of the 2,544 patients, 1254 (49.3%) underwent total mastectomy for their known cancer; 282 (22.5%) of these patients underwent immediate or delayed CPM. Overall, 171 patients (6.7%) had genetic testing; and the use of testing increased in the latter years of the study (3.% in 2000–2002 vs. 8.2% in 2003–2006, p<.0001). 49 of 171 patients had genetic testing prior to surgery. 10 had a deleterious BRCA1/2 mutation, 9 of whom had a CPM (p=.002). 14 patients without a mutation also had a CPM. Multivariate analysis revealed factors associated with use of CPM were: age younger than 50, white race, family history of breast cancer, higher clinical tumor stage, invasive lobular histology, and use of reconstruction (Table). Conclusions: Both patient and tumor characteristics influence selection of CPM. Although the use of genetic testing is increasing, most women elect to undergo CPM without having genetic testing. Evidence-driven models are needed to better inform women of their absolute risk of contralateral breast cancer as well as competing risk from their primary breast cancer in order to empower them in their active-decision-making.

[Table: see text]

No significant financial relationships to disclose.

Aberrant inducible nitric oxide synthase expression predicts poor survival in estrogen receptor negative breast cancer, and is associated with a gene expression signature similar to that of basal-like breast cancer

Abstract #5067

Background: Inducible nitric oxide synthase (iNOS) is a key enzyme in the inflammatory process, that catalyses the production nitric oxide (NO). NO is a free radical that affects the redox state of tumor cells and thus cell signaling. We hypothesized that iNOS expression is associated with markers of outcome and influences breast cancer survival by estrogen receptor (ER) α-independent mechanisms.&#x2028; Method: 248 cases of incident breast cancer were examined by IHC for iNOS expression. Univariate and multivariate analyses were performed to assess correlations between iNOS expression and clinico-pathological features of breast cancer, and patient survival. In addition, 35 tumors were laser capture microdissected and the effect of iNOS on gene expression profiles analyzed by Affymetrix gene expression arrays.&#x2028; Results: iNOS was moderately to strongly expressed in the majority of breast tumors (70%). iNOS was significantly associated markers of poor prognosis including p53 mutation accumulation, increased microvessel density, and high tumor grade. iNOS was not associated with race/ethnicity (143 African American, 105 Caucasian). In Cox regression analysis, high levels of iNOS expression was a predictor of both 5-year (Hazard Ratio - 5.41; 95% C.I. 1.25 to 23.48) and 10-year (H.R. 4.63; 95% C.I. 1.36 to 15.73) breast cancer-specific survival in women with ER-negative tumors. iNOS was not a predictor of ER positive breast cancer survival. Neither tumor p53 status nor chemotherapy modified these associations. Gene expression analysis identified changes in significant changes in gene expression with high levels of iNOS expression in ER negative breast cancer. This observation was not seen in ER positive breast cancer.&#x2028; 44% of the iNOS associated genes had previously been found to be associated with the ER negative breast cancer subtype, basal-like breast cancer phenotype.&#x2028; Discussion: These results suggest that iNOS contributes to the pathogenicity of ER-negative breast cancers and is a predictor of patient survival. The similarity of the iNOS induced gene signature to that of basal-like breast cancer, suggests that iNOS may play a role in the aggressive nature of basal-like breast cancer and may be a potential therapeutic target for the treatment of ER negative and basal-like breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5067.

Branching fraction measurements of B+-->rho+gamma, B0-->rho0gamma, and B0-->omegagamma

We present a study of the decays B+-->rho+gamma, B0-->rho0gamma, and B0-->omegagamma. The analysis is based on data containing 347 x 10(6) BB[over ] events recorded with the BABAR detector at the PEP-II asymmetric B factory. We measure the branching fractions B(B+-->rho+)gamma)=(1.10_(-0.33)(+0.37)+/-0.09)x10(-6) and B(B0-->rho0gamma)=(0.79(-0.20)(+0.22)+/-0.06)x10(-6), and set a 90% C.L. upper limit B(B0-->omegagamma)<0.78 x 10(-6). We also measure the isospin-averaged branching fraction B(B-->(rho/omega)gamma)=(1.25(-0.24)(+0.25)+/-0.09)x10(-6), from which we determine |Vtd/Vts|=0.200(-0.020)(+0.021)+/-0.015, where the first uncertainty is experimental and the second is theoretical.