Antioxidant potential and α-glucosidase inhibitory activity of onion (Allium cepa L.) peel and bulb extracts

Allium cepa L. is a commonly consumed vegetable that belongs to the Amaryllidaceae family and contains nutrients and antioxidants in ample amounts. In spite of the valuable food applications of onion bulb, its peel and outer fleshy layers are generally regarded as waste and exploration of their nutritional and therapeutic potential is still in progress with a very slow progression rate. The present study was designed with the purpose of doing a comparative analysis of the antioxidant potential of two parts of Allium cepa, i.g., bulb (edible part) and outer fleshy layers and dry peels (inedible part). Moreover, the inhibitory effect of the onion bulb and peel extracts on rat intestinal α-glucosidase and pancreatic α-amylase of porcine was also evaluated. The antioxidant potential of onion peel and bulb extracts were evaluated using 2,2-diphenyl- 1-picryl hydrazyl (DPPH), ferric-reducing antioxidant power assay (FRAP), 2,2'-azino-bis- 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay, H2O2 radical scavenging activity and Fe2+ chelating activity. Total flavonoids and phenolic content of ethanolic extract of onion peel were significantly greater as compared to that of onion bulb. Ethanolic extract of onion peel also presented better antioxidant and free-radical scavenging activity as compared to the ethanolic extract of bulb, while the aqueous extract of bulb presented weakest antioxidative potential. Onion peel extract's α-glucosidase inhibition potential was also correlated with their phenolic and flavonoid contents. The current findings presented onion peel as a possible source of antioxidative agents and phenolic compounds that might be beneficial against development of various common chronic diseases that might have an association with oxidative stress. Besides, outer dry layers and fleshy peels of onion exhibited higher phenolic content and antioxidant activities, compared to the inner bulb. The information obtained by the present study can be useful in promoting the use of vegetable parts other than the edible mesocarp for several future food applications, rather than these being wasted.

Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set

BACKGROUND

A multi-cancer early detection (MCED) test used to complement existing screening could increase the number of cancers detected through population screening, potentially improving clinical outcomes. The Circulating Cell-free Genome Atlas study (CCGA; NCT02889978) was a prospective, case-controlled, observational study and demonstrated that a blood-based MCED test utilizing cell-free DNA (cfDNA) sequencing in combination with machine learning could detect cancer signals across multiple cancer types and predict cancer signal origin (CSO) with high accuracy. The objective of this third and final CCGA substudy was to validate an MCED test version further refined for use as a screening tool.

PATIENTS AND METHODS

This pre-specified substudy included 4077 participants in an independent validation set (cancer: n = 2823; non-cancer: n = 1254, non-cancer status confirmed at year-one follow-up). Specificity, sensitivity, and CSO prediction accuracy were measured.

RESULTS

Specificity for cancer signal detection was 99.5% [95% confidence interval (CI): 99.0% to 99.8%]. Overall sensitivity for cancer signal detection was 51.5% (49.6% to 53.3%); sensitivity increased with stage [stage I: 16.8% (14.5% to 19.5%), stage II: 40.4% (36.8% to 44.1%), stage III: 77.0% (73.4% to 80.3%), stage IV: 90.1% (87.5% to 92.2%)]. Stage I-III sensitivity was 67.6% (64.4% to 70.6%) in 12 pre-specified cancers that account for approximately two-thirds of annual USA cancer deaths and was 40.7% (38.7% to 42.9%) in all cancers. Cancer signals were detected across >50 cancer types. Overall accuracy of CSO prediction in true positives was 88.7% (87.0% to 90.2%).

CONCLUSION

In this pre-specified, large-scale, clinical validation substudy, the MCED test demonstrated high specificity and accuracy of CSO prediction and detected cancer signals across a wide diversity of cancers. These results support the feasibility of this blood-based MCED test as a complement to existing single-cancer screening tests.

CLINICAL TRIAL NUMBER

NCT02889978.

Trends in the diffusion of robotic surgery in prostate, uterus, and colorectal procedures: a retrospective population-based study

This study aimed to propose quantifiable metrics on the adoption lifecycle of robotic-assisted surgery (RAS) within and across prostate, hysterectomy, and colorectal procedures. This was a retrospective population-based cohort study of commonly performed RAS procedures in the US conducted from July 2001 to July 2015. The patients were identified from the Premier Hospital Database using International Classification of Diseases, 9th revision, Clinical Modification codes denoting prostate, uterus, and colorectal procedures. The Diffusion of Innovations theory was applied to percent RAS utilization to determine discrete eras of technology adoption. Overall and by-era patient baseline characteristics were compared between robotic and non-robotic groups. This study included a total of 2,098,440 RAS procedures comprising prostate (n = 155,342), uterus (n = 1,300,046), and colorectal (n = 643,052) procedures. Prostate (76.7%) and uterus (28.9%) procedures had the highest robotic utilization by the end of the study period and appear to be in the last adoption era (Laggard). However, robotic utilization in colorectal procedures (7.5%) was low and remained in the first era (Innovator) for a longer time (15 vs 60 vs 135 months). Whites, privately insured, patients with fewer comorbidities, and those admitted in large teaching hospitals were more likely to undergo RAS in the early study period. AS-associated patient and hospital profiles changed over time, suggesting that selected patient cohorts should be contextualized by overall adoption of a novel medical technology. The time-discretized analysis may also inform patient selection criteria and appropriate timing for clinical study stages proposed by the Idea, Development, Exploration, Assessment, Long-term study-Devices framework.

Medical device active surveillance of spontaneous reports: A literature review of signal detection methods

PURPOSE

The collection and analysis of real-world data for the active monitoring of medical device performance and safety has become increasingly important. Spontaneous reports, such as those in the Food & Drug Administration's (FDA's) Manufacturer and User Facility Device Experience (MAUDE), provide early warning of potential issues with marketed devices. This review synthesizes the current literature on medical device surveillance signal detection and provides a framework for application of methods to active surveillance of spontaneous reports.

METHODS

Ovid MEDLINE, Ovid Embase, Scopus, and PubMed databases were systematically searched up to January 2019. Additionally, five methods articles from pharmacovigilance were added that had potential applications to medical devices.

RESULTS

Among 105 articles included, the most common source of data (84%) was registries; median time between data collection and publication was 8 years. Surgical procedure outcome signal detection articles comprised 83% while 14% were on device outcome signal detection. The most common family of methods cited (70%) was Sequential Probability Ratio.

CONCLUSION

Application of any signal detection algorithm requires careful consideration of influential factors, data limitations, and algorithmic assumptions. We recommend approaches using disproportionality, statistical process control, and sequential probability tests and provide R packages to further development efforts. The small number of published examples suggest that further development of statistical methods and technological solutions to analyze large amounts of data for device safety and performance is needed. Fundamental differences in products, data infrastructure, and the regulatory landscape suggest that medical device vigilance requires its own body of research distinct from pharmacovigilance.

Alzheimer's disease: insights for risk evaluation and prevention in the Chinese population and the need for a comprehensive programme in Hong Kong/China

With the ageing of the global population, China is projected to be impacted significantly by the rising number of patients with Alzheimer's disease (AD). A cure for AD is not yet available, so society should be prepared for an increasing AD-related burden. In this review, we examine this impending problem and provide overviews on (a) the magnitude of the problem of AD in Hong Kong/China in the near future; (b) the genetic and lifestyle risk factors that contribute to AD; (c) current diagnostic approaches and the potential of newly discovered genetic biomarkers for early detection; (d) medications, non-pharmacological interventions, and possible preventive measures; and (e) the need for social and psychological care from the community. In Hong Kong, primary care and AD-related support for at-risk individuals, patients, and caregivers are inadequate. A joint effort from the medical community, government, universities, non-governmental organisations/charities, and industry should initiate the development of a long-term programme for AD. Finally, we outline recommendations for the relevant parties to consider.

The Impact of Surgical Approach on Late Recurrence in Incisional Hernia Repair

Background and Objectives:

We conducted a retrospective, observational study to compare real-world recurrence rates for different surgical approaches after incisional hernia mesh repair.

Methods:

Two large US insurance claims databases, Truven Commercial Claims (CCAE) and Medicare Supplemental (MDCR), were evaluated for the period from 2009 to 2015. The first incisional hernia repair with mesh for patients 21 years or older was identified (INDEX). One-year continuous enrollment before INDEX was required. Mesh and approach (OPEN, laparoscopic [LAP], and conversion [CONV]) were identified with the use of CPT-4/ICD-9 codes. Recurrence was defined as a second incisional hernia repair 31 days or longer after INDEX. Kaplan-Meier (KM) estimates and Cox models were used to analyze the effect of approach on recurrence.

Results:

A total of 68,560 patients were identified for CCAE (78.7%) and MDCR (21.3%) with a mean (SD) age of 55.3 (12.8) years. The majority of procedures were OPEN (80.1%) followed by LAP (16.3%) and CONV (3.6%). OPEN had fewer female patients 53.7% compared with LAP (62.1%) and CONV (62.2%). CONV represented more inpatient (51.9%) procedures compared with LAP (41.0%) and OPEN (27.3%). Starting at 2 years post-INDEX, LAP (5.1%, 95% confidence interval [CI] 4.5%–5.6%) had lower KM estimates compared with OPEN (5.9%, 95% CI 5.7%–6.2%]); after 3 years, LAP (6.8%, 95% CI 6.2%–7.5%]) had lower estimates than both OPEN (7.9%, 95% CI 7.6%–8.3%) and CONV (9.3%, 95% CI 7.6%–11.0%). After controlling for confounders, the risk was lower for LAP compared with OPEN (hazard ratio 0.839, 95% CI 0.752–0.936) and CONV (hazard ratio 0.808, 95% CI 0.746–0.875), while OPEN and CONV were not significantly different from each other.

Conclusion:

Successful laparoscopic surgery incisional hernia mesh repair was associated with decreased risk of recurrence compared with OPEN and CONV.

HIV treatment and monitoring patterns in routine practice: a multi-country retrospective chart review of patient care

Background: A study of patient records in four HIV clinics in three sub-Saharan African countries examined routine clinical care patterns and variations.

Methods: Clinic characteristics were described, and patient data extracted from a sample of medical records. Data on treatment, CD4 count and viral load (VL) were obtained for the last visit in the records, dates mainly between 2015 and 2017, patient demographic data were obtained from the first clinic visit.

Results: Four clinics, two in Nigeria, one in Zambia and one in Uganda, all public facilities, using national HIV treatment guidelines were included. Numbers of patients and health professionals varied, with some variation in stated frequency of testing for CD4 count and VL. Clinical guidelines were available in each clinic, and most drugs were available free to patients. The proportion of patients with a CD4 count in the records varied from 84 to 100 percent, the latest median count varied from 269 to 593 between clinics. 35% had a record of a VL test, varying from 1% to 63% of patients. Lamivudine (3TC) was recorded for more than 90% of patients in each clinic, and although there was variation between clinics in the choice of antiretroviral therapy (ART), the majority were on first line drugs consistent with guidelines.  Only about 2% of the patients were on second-line ARTs. In two clinics, 100% and 99% of patients were prescribed co-trimoxazole, compared with 7% and no patients in the two other clinics.

Conclusions: The wide variation in available clinic health work force, levels and frequency of CD4 counts, and VL assessment and treatment indicate sub-optimal adherence to current guidelines in routine clinical care. There is room for further work to understand the reasons for this variation, and to standardise record keeping and routine care of HIV positive patients.

Simulating real-life exposures to uncover possible risks to human health: A proposed consensus for a novel methodological approach

In real life, consumers are exposed to complex mixtures of chemicals via food, water and commercial products consumption. Since risk assessment usually focuses on individual compounds, the current regulatory approach doesn't assess the overall risk of chemicals present in a mixture. This study will evaluate the cumulative toxicity of mixtures of different classes of pesticides and mixtures of different classes of pesticides together with food additives (FAs) and common consumer product chemicals using realistic doses after long-term exposure. Groups of Sprague Dawley (CD-SD) rats (20 males and 20 females) will be treated with mixtures of pesticides or mixtures of pesticides together with FAs and common consumer product chemicals in 0.0, 0.25 × acceptable daily intake (ADI)/tolerable daily intake (TDI), ADI/TDI and 5 × ADI/TDI doses for 104 weeks. All animals will be examined every day for signs of morbidity and mortality. Clinical chemistry hematological parameters, serum hormone levels, biomarkers of oxidative stress, cardiotoxicity, genotoxicity, urinalysis and echocardiographic tests will be assessed periodically at 6 month intervals. At 3-month intervals, ophthalmological examination, test for sensory reactivity to different types of stimuli, together with assessment of learning abilities and memory performance of the adult and ageing animals will be conducted. After 24 months, animals will be necropsied, and internal organs will be histopathologically examined. If the hypothesis of an increased risk or a new hazard not currently identified from cumulative exposure to multiple chemicals was observed, this will provide further information to public authorities and research communities supporting the need of replacing current single-compound risk assessment by a more robust cumulative risk assessment paradigm.

Extracellular ATP Induces Calcium Signaling in Odontoblasts

Odontoblasts form dentin at the outermost surface of tooth pulp. An increasing level of evidence in recent years, along with their locational advantage, implicates odontoblasts as a secondary role as sensory or immune cells. Extracellular adenosine triphosphate (ATP) is a well-characterized signaling molecule in the neuronal and immune systems, and its potential involvement in interodontoblast communications was recently demonstrated. In an effort to elaborate the ATP-mediated signaling pathway in odontoblasts, the current study performed single-cell reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescent detection to investigate the expression of ATP receptors related to calcium signal in odontoblasts from incisal teeth of 8- to 10-wk-old rats, and demonstrated an in vitro response to ATP application via calcium imaging experiments. While whole tissue RT-PCR analysis detected P2Y₂, P2Y₄, and all 7 subtypes (P2X₁ to P2X₇) in tooth pulp, single-cell RT-PCR analysis of acutely isolated rat odontoblasts revealed P2Y₂, P2Y₄, P2X₂, P2X₄, P2X₆, and P2X₇ expression in only a subset (23% to 47%) of cells tested, with no evidence for P2X₁, P2X₃, and P2X₅ expression. An increase of intracellular Ca²⁺ concentration in response to 100μM ATP, which was repeated after pretreatment of thapsigargin or under the Ca²⁺-free condition, suggested function of both ionotropic and metabotropic ATP receptors in odontoblasts. The enhancement of ATP-induced calcium response by ivermectin and inhibition by 5-(3-bromophenyl)-1,3-dihydro-2H-benzofuro[3,2-e]-1,4-diazepin-2-one (5-BDBD) confirmed a functional P2X₄ subtype in odontoblasts. Positive calcium response to 2',3'-O-(benzoyl-4-benzoyl)-ATP (BzATP) and negative response to α,β-methylene ATP suggested P2X₂, P2X₄, and P2X₇ as functional subunits in rat odontoblasts. Single-cell RT-PCR analysis of the cells with confirmed calcium response and immunofluorescent detection further corroborated the expression of P2X₄ and P2X₇ in odontoblasts. Overall, this study demonstrated heterogeneous expression of calcium-related ATP receptor subtypes in subsets of individual odontoblasts, suggesting extracellular ATP as a potential signal mediator for odontoblastic functions.

Abstract P5-14-04: A phase 2 study evaluating orteronel, an inhibitor of androgen biosynthesis, in patients with androgen receptor (AR)-expressing metastatic breast cancer: Interim analysis

Background: The frequency of AR expression varies in the different breast cancer subtypes with 88%, 59%, and 32% expression reported in ER+, HER2+, and triple negative tumors, respectively. AR expression is associated with resistance to endocrine therapy in ER+ breast cancer. Androgen levels frequently increase following treatment with aromatase inhibitors suggesting a role for androgen synthesis inhibitors in ER+ breast cancer. AR signaling and expression are seen in triple negative breast cancer (TNBC), and a distinct AR TNBC subtype can be identified by gene expression profiling. AR expression in TNBC offers a potential therapeutic target. Preclinical and clinical studies demonstrated anti-androgen agent activity in breast cancer cell lines; preliminary clinical data suggests activity in TNBC. Orteronel is a novel, oral, selective, nonsteroidal inhibitor of 17, 20-lyase, a key enzyme in androgen biosynthesis that is being evaluated as endocrine therapy in various hormone-sensitive cancers. In this phase 2 study we are evaluating single agent orteronel in AR+ MBC.

Methods: Pts with AR expressing MBC (≥10% staining by central immunohistochemistry) were eligible. Pts were grouped into 2 cohorts for analysis: Cohort 1-TNBC and Cohort 2-ER+ (HER2 could be +/- in this cohort). Pts must have been previously treated with standard therapy for MBC (1-3 chemotherapy regimens for TNBC, 1-3 hormonal therapies + 1 chemotherapy for ER+ patients, ≥2 HER2-targeted regimens for HER2+ patients). A 6 pt lead-in for safety and tolerability of orteronel in AR+ female MBC pts was followed by open enrollment to either cohort. All pts received 300 mg orteronel PO BID over a 4 week cycle and underwent response assessment every 2 cycles. Treatment was continued until disease progression or unacceptable toxicity. The hypothesized response rate for Cohort 1 was 10% and 13% for Cohort 2. We present the results of a protocol-specified interim analysis of the ER+ MBC pts (Cohort 2).

Results: From 3/2014 to 4/2015, a total of 29 pts were enrolled on cohort 2. Median age was 65 years (range, 39-79); 90% ECOG ≤1; 90% HER2-/10% HER2+; median of 7 prior therapies (range 3-11). 93% had prior chemotherapy. Pts received a median of 2 cycles of orteronel treatment (range 1-4) and 3 pts (10%) are still on treatment. Of the 26 pts (90%) pts that have discontinued, 19 (66%) discontinued due to disease progression, 4 (14%) due to pt decision, 2 (7%) due to adverse event (AE), and 1 (3%) due to non-compliance. The most common treatment-related G 3/4 AEs were increased lipase [3 pts (10%)] and hypertension [2 pts (7%)]. There were no treatment-related SAEs or deaths on study. Three pts (10%) had stable disease as their best response. Further response evaluation is underway.

Conclusions: Orteronel monotherapy was well tolerated but appears to have limited single-agent activity in this heavily pre-treated ER+ MBC pt population. The full results from this interim analysis will be presented.

Citation Format: Yardley DA, Peacock N, Young RR, Silber A, Chung G, Webb CD, Jones SF, Shastry M, Midha R, DeBusk LM, Hainsworth JD, Burris HA. A phase 2 study evaluating orteronel, an inhibitor of androgen biosynthesis, in patients with androgen receptor (AR)-expressing metastatic breast cancer: Interim analysis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-14-04.

Desipramine inhibits salivary Ca(2+) signaling and aquaporin translocation

OBJECTIVE

Desipramine is a tricyclic antidepressant with a negative side effect of dry mouth. The Na(+) /H(+) exchanger was suggested to be a target of desipramine in salivary gland cells. However, it is unclear whether desipramine has other targets in the salivary secretion pathway. Here, we studied the effect of desipramine on salivary Ca(2+) signaling.

MATERIALS AND METHODS

Cytosolic free Ca(2+) concentration ([Ca(2+) ]i ) was determined with the fluorescent Ca(2+) indicator fura-2/AM. Aquaporin translocation was analyzed by Western blotting and immunocytochemistry of confocal microscopy.

RESULTS

Desipramine inhibited the carbachol- and histamine-mediated increase in cytosolic Ca(2+) ([Ca(2+) ]i ) in a concentration-dependent manner. However, desipramine did not affect increases in [Ca(2+) ]i mediated by extracellular ATP, sphingosine-1-phosphate, or thapsigargin. The adrenergic receptor blockers prazosin and propranolol did not reverse the desipramine-mediated inhibition of carbachol- and histamine-induced increases in [Ca(2+) ]i . We also found that desipramine inhibits the increase in membrane aquaporin-5 level triggered by carbachol and histamine treatments.

CONCLUSIONS

These results imply that desipramine blocks muscarinic and histamine receptor-mediated Ca(2+) signaling and the subsequent translocation of aquaporin-5 in human salivary gland cells, suggesting a novel mechanism for the xerogenic effects of desipramine.

Quantitative evaluation of the onset and longevity of the action of incobotulinumtoxinA by skin displacement analysis in the treatment of glabellar frown lines

BACKGROUND

A quantitative numerical method for assessing the extent and duration of the inhibitory action of botulinum neurotoxin type A on mimetic muscles would potentially enable more detailed evaluation of the overall efficacy of this aesthetic treatment.

AIM

To evaluate skin displacement analysis (SDA) as a tool for assessment of the extent and duration of effect of incobotulinumtoxinA on mimetic muscles in the glabellar region in routine daily practice.

METHODS

A total dose of 30 U incobotulinumtoxinA was injected into the fronto-glabellar region of 16 subjects. SDA was performed at baseline and during onset and recovery from incobotulinumtoxinA treatment at various timepoints up to 24 weeks after treatment. The reference point for SDA was located at the upper margin of the eyebrow, 30 mm lateral to the median line. To correlate and validate SDA results, semi-quantitative wrinkle score assessments were performed in parallel.

RESULTS

At baseline, the mean horizontal skin displacement was 5.4 mm (standard deviation: ± 1.4 mm). During onset of action after treatment, skin displacement values decreased from baseline (100%) by 46%, 85%, and 90% at day 2, week 1, and week 2, respectively. During recovery from incobotulinumtoxinA action, skin displacement values increased to 33%, 50%, and 93% of the baseline value at 6, 12, and 24 weeks after treatment, respectively. The inhibitory effect of incobotulinumtoxinA was highly variable among subjects, ranging from 25% to 68% of the baseline value 12 weeks after treatment. Overall agreement between SDA values and wrinkle scores was good.

CONCLUSION

SDA represents a novel, objective method for the quantitative evaluation of the effect of incobotulinumtoxinA on mimetic muscles underlying the fronto-glabellar region, and showed good correlation with wrinkle score assessments. Both SDA and wrinkle score indicated the persistence of treatment effects 24 weeks after injection.

Activation of transient receptor potential ankyrin 1 by eugenol

Eugenol is a bioactive plant extract used as an analgesic agent in dentistry. The structural similarity of eugenol to cinnamaldehyde, an active ligand for transient receptor potential ankyrin 1 (TRPA1), suggests that eugenol might produce its effect via TRPA1, in addition to TRPV1 as we reported previously. In this study, we investigated the effect of eugenol on TRPA1, by fura-2-based calcium imaging and patch clamp recording in trigeminal ganglion neurons and in a heterologous expression system. As the result, eugenol induced robust calcium responses in rat trigeminal ganglion neurons that responded to a specific TRPA1 agonist, allyl isothiocyanate (AITC), and not to capsaicin. Capsazepine, a TRPV1 antagonist failed to inhibit eugenol-induced calcium responses in AITC-responding neurons. In addition, eugenol response was observed in trigeminal ganglion neurons from TRPV1 knockout mice and human embryonic kidney 293 cell lines that express human TRPA1, which was inhibited by TRPA1-specific antagonist HC-030031. Eugenol-evoked TRPA1 single channel activity and eugenol-induced TRPA1 currents were dose-dependent with EC50 of 261.5μM. In summary, these results demonstrate that the activation of TRPA1 might account for another molecular mechanism underlying the pharmacological action of eugenol.

Abstract P3-14-02: Patterns of the use of primary systemic therapy in the United States

Background: Primary systemic therapy (PST) is an accepted alternative to adjuvant systemic therapy of breast cancer. It provides equivalent survival, increased breast conservation rates, and prognostic information.

Methods: This analysis assesses patterns of PST use based on information collected by the National Cancer Database (NCDB), a joint project of the American College of Surgeons and the American Cancer Society which captures data on over 70% of all diagnosed breast cancer patients in the U.S. Using the b-participant use file of the NCDB, we evaluated regional, patient, and tumor factors associated with PST use.

Results: The NCDB captured 621,319 patients treated with PST from 2006 to 2010. Of these, 7.4% received systemic therapy pre-operatively, and 3.6% in both the pre- and post-operative settings. Factors correlating with timing of therapy are shown in the table. PST use increased steadily from 7.0% to 7.8% (p<0.001) from 2006 to 2010. PST was significantly more frequently used in younger, African-American, Hispanic, low-income, uninsured patients with larger, node positive tumors, living in large metropolitan areas in the West and treated in academic centers. These factors remained significantly and independently associated with PST on multivariate analysis.

 UnivariateMultivariateFactorPre-opPost-opBothp-valuep-valueYear of Diagnosis   <0.001<0.00120067.0%90.0%3.0%  20077.1%89.5%3.4%  20087.2%89.2%3.6%  20097.6%88.6%3.8%  20107.8%87.7%4.5%  Region   <0.001<0.001Northeast5.7%90.9%3.4%  Atlantic6.7%90.4%2.9%  Southeast8.0%88.2%3.8%  Great Lakes6.5%90.1%3.4%  South7.7%88.4%3.9%  Midwest5.2%90.2%4.6%  West11.4%84.2%4.4%  Mountain8.8%88.7%2.5%  Pacific7.7%88.3%4.0%  Community type (pop):   <0.001<0.001Metro (>1M)7.9%88.3%3.8%  Metro (250K-1M)7.1%89.5%3.4%  Metro (<250K)6.3%90.5%3.2%  Urban, adjacent to a metro area (20K+)6.5%90.0%3.5%  Urban, not adjacent to metro (20K+)6.3%90.5%3.2%  Urban, adjacent to metro (2500-19,999)6.7%89.4%4.0%  Urban, not adjacent to metro (2500-19,999)6.0%90.6%3.4%  Rural/urban pop, adjacent to metro (<2500)6.0%90.3%3.8%  Rural/urban pop, not adjacent to metro (<2500)5.7%90.5%3.8%  Facility type:   <0.001<0.001Community program6.4%90.5%3.1%  Comprehensive community program7.1%89.5%3.5%  Academic/research8.4%87.4%4.2%  Other6.4%90.0%3.6%  Age:   <0.001<0.001<609.4%85.8%4.8%  ≥604.9%92.9%2.3%  Race:   <0.001<0.001Caucasian6.7%89.3%3.5%  African-American11.8%83.3%4.9%  Other8.4%87.5%4.1%  Ethnicity:   <0.001<0.001Non-Hispanic7.2%89.3%3.6%  Hispanic11.2%83.3%5.4%  Median household income:   <0.0010.023<$30K9.0%86.8%4.2%  $30K-$34,9997.7%88.6%3.7%  $35K-$45,9997.2%89.1%3.7%  $46K+6.9%89.6%3.4%  Insurance:   <0.001<0.001Uninsured15.3%78.1%6.6%  Private7.8%88.3%3.9%  Medicaid13.7%79.2%7.2%  Medicare4.8%93.0%2.2%  Military8.2%87.5%4.4%  Clinical T stage:   <0.001<0.001T12.4%96.4%1.2%  T213.6%79.5%6.9%  T3-T435.9%45.3%18.8%  Clinical N stage:   <0.001<0.001N04.8%92.9%2.3%  N1-326.0%60.3%13.7%  pop: population; multivariate OR and 95% CI not shown

Conclusion: PST appears to be underutilized, received by only 7.8% of all patients, 36% of T3-T4 tumors, and 26.0% of clinically node positive patients. However, its rate of use has increased over the past years. There is also significant regional variation in the use of PST, independent of patient and tumor factors.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-02.

Abstract P6-11-03: Follow up of breast cancer patients who underwent gamma knife radiosurgery for a diagnosis of brain metastases: A single institutional experience

Background: Breast cancer (BC) is the second most common cause of brain metastases in the United States. We performed a retrospective analysis of BC patients (pts) in the Yale Gamma Knife Radiosurgery (GKRS) database treated for brain metastases (mets) to report overall survival (OS) from time of GKRS, and to identify factors that predict improved survival outcomes.

Methods: We performed retrospective review of the Yale database of BC pts treated with standard GKRS technique for brain mets from 2000 to May 2013. Treatment doses typically ranged from 16 to 24 Gy prescribed to the 40-85% isodose surfaces. Overall survival (OS) for each patient was calculated from the date of first GKRS treatment of brain metastases. Variables included age, Karnofsky Performance Status (KPS), pre/post whole-brain radiation treatment (WBRT) and/or surgical resection, and # of brain mets treated (1-4 vs ≥5).

Results: A total of 80 BC pts were identified, with a mean age of 56.2 yrs; KPS 40-60 in 8pts (10%), 70-80 in 13 (16%), 90-100 in 41 (51%), unknown in 18 (23%); ER+ in 38 (48%), ER- in 38 (48%), unknown in 4 (5%); HER2 + in 38 (48%), HER2- in 33 (41%), indeterminate in 3 (4%) and unknown in 6 (8%). BC subtypes are Luminal A (ER+/HER2-) in 16 (20%), Luminal B (ER+/HER2+) in 19 (24%), HER-2(ER-/HER2+) in 17 (21%), Basal (ER-/HER2-) in 17 (21%), unknown in 11 (14%). Number of brain mets at time of first GKRS ≥5 in 32 (40%); prior WBRT in 30 (38%); WBRT post GKRS in 9 (11%); surgical resection for brain mets in 13 (16%) prior to GKRS and post GKRS in 9 (11%); 16% had ≥3 GKRS. Median time from primary BC dx to brain mets is 62.8 months (m) (range 46.2-81.6); with no significant difference among subtypes. Median OS from GKRS is 13.1 m (7.6-21.9); median OS from brain mets is 18.8 m (11.7-23.9). On univariate analysis, factors associated with significant improved OS from time of GKRS included HER-2 subtype (p = 0.005), KPS 90-100 (p = 0.008), good control of systemic disease (p = 0.017), pre (p = 0.041) and post GKRS surgical resection (p = 0.02). Age, pre or post WBRT, # of brain mets (1-4 vs. 5) were not significant predictors of OS from time of GKRS. In a multivariate Cox analysis (46 cases), HER-2 subtype remained a significant predictor of improved OS from time of GKRS; (HR) 0.26, 95%CI 0.08 to 0.8, p-value = 0.02. There was a trend in favor of surgical resection of brain mets pre GKRS (HR 0.14, 95% CI 0.02 to 1.15, p-value = 0.067

Conclusion: GKRS offers good local control for BC pts with brain mets, and is a reasonable option for pts with ≥5 brain mets. Our results show no associated survival benefit for administration of WBRT pre/post GKRS. HER-2 subtype is a significant predictor of improved survival in BC pts undergoing GKRS for brain mets.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-03.

Abstract P5-13-05: Richer and wiser: Factors correlated with chemoprevention use in the United States

Introduction: Tamoxifen and raloxifene have been shown to reduce the risk of breast cancer by up to 50%, yet the uptake of these agents remains poor. We sought to determine factors associated with chemoprevention uptake in a nationally representative sample.

Methods: The National Health Interview Survey (NHIS) is a population-based survey conducted annually by the CDC and is designed to be representative of the non-institutionalized civilian population in the United States. We utilized data from the 2010 NHIS cancer supplement to determine factors associated with chemoprevention uptake in women ≥ 35 years of age. Statistical analyses were conducted using SUDAAN software.

Results: In 2010, 10,959 women ≥ 35 years of age were surveyed, representing 83,377,082 people in the population. Of these, 0.21% reported taking chemoprevention, using either tamoxifen or raloxifene. On bivariate analyses, factors correlating with chemoprevention uptake included age, race/ethnicity, education, insurance, income and geographic region (see Table). Interestingly, MRI use, family history of premenopausal breast cancer in first degree relatives, and personal risk perception were not associated with chemoprevention use. On multivariate analysis, education and income remained independent predictors of chemoprevention use.

Conclusion: Approximately 0.2% of women take chemoprevention. It is concerning that sociodemographic factors of education and income are independent predictors of the use of chemopreventive agents for breast cancer, while risk perception and family history do not seem to correlate with uptake rates. These findings are a call to action for improved education and counseling of those who are at greatest risk, and highlight potential disparities in access to appropriate chemoprevention across all sociodemographic groups.

Bivariate and Multivariate Analyses of Factors Correlated with Chemoprevention UptakeFactorBivariate AnalysisMultivariate Analysis Chemoprevention (%)No Chemoprevention (%)p-valueOR (95% CI)p-valueAge  0.0481 0.1087< 40 yr3.2211.93 1.00 40-49 yr5.8726.11 0.78 (0.05-12.44) 50-59 yr11.7024.88 1.44 (0.10-21.43) 60-69 yr23.8218.54 3.15 (0.32-31.41) 70-79 yr44.4110.77 8.62 (0.78-94.75) 80+ yr10.997.77 1.53 (0.10-23.66) Race/ethnicity  0.0006 0.8372Hispanic3.9011.06 00.81 (0.11-5.85) White96.1071.63 1.00 Black011.80 - Asian04.61 - Other00.89 - Education  0.0371 <0.0001< Grade 127.1214.15 1.00 High School25.8627.73 1.86 (0.35-9.75) Some college/Assoc21.4229.97 1.85 (0.36-9.45) Bachelors15.5917.49 1.44 (0.13-16.35) Masters11.708.37 3.23 (0.41-25.14) Prof/Doctorate18.302.28 25.22 (4.30-147.87) Insurance  0.0002 0.0686Not covered012.44 - Medicare72.6129.38 1.00 Medicaid3.224.50 2.38 (0.22-26.15) Military01.74 - Private24.1751.94 0.28 (0.06-1.26) Income  0.0005 0.0306<$35K32.3934.53 1.00 $35K-$74,99926.1131.53 0.97 (0.21-4.42) $75K-$99,999012.08 - $100K+41.6021.86 3.78 (0.94-15.22) Region  0.0441 0.1649Northeast27.9318.62 1.00 Midwest31.6022.88 0.92 (0.32-2.64) South34.4935.66 0.65 (0.21-2.04) West5.9822.84 0.16 (0.03-0.86) Oophorectomy40.1115.160.08132.17 (0.77-6.09)0.1404MRI use2.315.170.2597  Family History2.315.130.2601  Risk Perception  0.1451  High41.5212.50   Average25.8947.49   Low32.5940.01   

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-13-05.

Pain fiber anesthetic reduces brainstem Fos after tooth extraction

We recently demonstrated that pain-sensing neurons in the trigeminal system can be selectively anesthetized by co-application of QX-314 with the TRPV1 receptor agonist, capsaicin (QX cocktail). Here we examined whether this new anesthetic strategy can block the neuronal changes in the brainstem following molar tooth extraction in the rat. Adult male Sprague-Dawley rats received infiltration injection of anesthetic 10 min prior to lower molar tooth extraction. Neuronal activation was determined by immunohistochemistry for the proto-oncogene protein c-Fos in transverse sections of the trigeminal subnucleus caudalis (Sp5C). After tooth extraction, c-Fos-like immunoreactivity (Fos-LI) detected in the dorsomedial region of bilateral Sp5C was highest at 2 hrs (p < .01 vs. naïve ipsilateral) and declined to pre-injury levels by 8 hrs. Pre-administration of the QX cocktail significantly reduced to sham levels Fos-LI examined 2 hrs after tooth extraction; reduced Fos-LI was also observed with the conventional local anesthetic lidocaine. Pulpal anesthesia by infiltration injection was confirmed by inhibition of the jaw-opening reflex in response to electrical tooth pulp stimulation. Our results suggest that the QX cocktail anesthetic is effective in reducing neuronal activation following tooth extraction. Thus, a selective pain fiber 'nociceptive anesthetic' strategy may provide an effective local anesthetic option for dental patients in the clinic.

Cellular and molecular mechanisms of dental nociception

Due, in part, to the unique structure of the tooth, dental pain is initiated via distinct mechanisms. Here we review recent advances in our understanding of inflammatory tooth pain and discuss 3 hypotheses proposed to explain dentinal hypersensitivity: The first hypothesis, supported by functional expression of temperature-sensitive transient receptor potential channels, emphasizes the direct transduction of noxious temperatures by dental primary afferent neurons. The second hypothesis, known as hydrodynamic theory, attributes dental pain to fluid movement within dentinal tubules, and we discuss several candidate cellular mechanical transducers for the detection of fluid movement. The third hypothesis focuses on the potential sensory function of odontoblasts in the detection of thermal or mechanical stimuli, and we discuss the accumulating evidence that supports their excitability. We also briefly update on a novel strategy for local nociceptive anesthesia via nociceptive transducer molecules in dental primary afferents with the potential to specifically silence pain fibers during dental treatment. Further understanding of the molecular mechanisms of dental pain would greatly enhance the development of therapeutics that target dental pain.

Comparing effects of kyphoplasty, vertebroplasty, and non-surgical management in a systematic review of randomized and non-randomized controlled studies

PURPOSE

To determine if differences in safety or efficacy exist between balloon kyphoplasty (BKP), vertebroplasty (VP) and non-surgical management (NSM) for the treatment of osteoporotic vertebral compression fractures (VCFs).

METHODS

As of February 1, 2011, a PubMed search (key words: kyphoplasty, vertebroplasty) resulted in 1,587 articles out of which 27 met basic selection criteria (prospective multiple-arm studies with cohorts of ≥ 20 patients). This systematic review adheres to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.

RESULTS

Pain reduction in both BKP (-5.07/10 points, P < 0.01) and VP (-4.55/10, P < 0.01) was superior to that for NSM (-2.17/10), while no difference was found between BKP/VP (P = 0.35). Subsequent fractures occurred more frequently in the NSM group (22 %) compared with VP (11 %, P = 0.04) and BKP (11 %, P = 0.01). BKP resulted in greater kyphosis reduction than VP (4.8º vs. 1.7°, P < 0.01). Quality of life (QOL) improvement showed superiority of BKP over VP (P = 0.04), along with a trend for disability improvement (P = 0.08). Cement extravasation was less frequent in the BKP (P = 0.01). Surgical intervention within the first 7 weeks yielded greater pain reduction than VCFs treated later.

CONCLUSIONS

BKP/VP provided greater pain relief and fewer subsequent fractures than NSM in osteoporotic VCFs. BKP is marginally favored over VP in disability improvement, and significantly favored in QOL improvement. BKP had a lower risk of cement extravasation and resulted in greater kyphosis correction. Despite this analysis being restricted to Level I and II studies, significant heterogeneity suggests that the current literature is delivering inconsistent messages and further trials are needed to delineate confounding variables.

Characterization of Dental Nociceptive Neurons

Selective blockade of nociceptive neurons can be achieved by the delivery of permanently charged sodium channel blockers through the pores of nociceptive ion channels. To assess the feasibility of this application in the dental area, we investigated the electrophysiological and neurochemical characteristics of nociceptive dental primary afferent (DPA) neurons. DPA neurons were identified within trigeminal ganglia labeling with a retrograde fluorescent dye applied to the upper molars of adult rats. Electrophysiological studies revealed that the majority of dental primary afferent neurons showed characteristics of nociceptive neurons, such as sensitivity to capsaicin and the presence of a hump in action potential. Immunohistochemical analysis revealed a large proportion of DPA neurons to be IB4-positive and to express TRPV1 and P2X3. Single-cell RT-PCR revealed mRNA expression of various nociceptive channels, including the temperature-sensitive TRPV1, TRPA1, TRPM8 channels, the extracellular ATP receptor channels P2X2 and P2X3, as well as the nociceptor-specific sodium channel, NaV1.8. In conclusion, DPA neurons have the electrophysiological characteristics of nociceptors and express several nociceptor-specific ion channels. Analysis of these data may assist in the search for a new route of entry for the delivery of membrane-impermeant local anesthetics. Abbreviations: AP, action potential; DiI, 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate; DPA, dental primary afferent; FITC, fluorescein 5(6)-isothiocyanate; IB4, isolectin-B4; RT-PCR, reverse-transcription polymerase chain-reaction; TRP, transient receptor potential.

Abstract P3-14-17: Trastuzumab (H) and Rapamycin (R) for Treatment of HER-2 Overexpressing Metastatic Breast Cancer (BC) with Prior Disease Progression on H Based Therapy: Safety and Pharmacodynamic (PD) Results

Background: Preclinical data shows upregulation of the PI3K/AKT pathway and synergistic cytotoxicty between H+R in sensitive and resistant HER-2 overexpressing BC cell lines.

Methods: We designed a phase II clinical trial with an early stopping rule for excess toxicity in the first 4 wks of H+R therapy, defined as ≥3 cases of drug related grade 3 or 4 toxicity observed in the first 9 pts enrolled on trial. We report safety and PD results in 11 pts treated with oral R 6 mg daily + standard dosesand schedule of H. LVEF by ECHO or MUGA was assessed at baseline and every 3 months thereafter; treatment was held for LVEF drop below normal limits or ≥20 percentage points. Pre and post therapy tumor samples were collected when feasible. Circulating tumor (CTC) and endothelial (CEC) cells were collected and analyzed using the Veridex Cell Search System at baseline, wks 1, 2 and 4 and with every restaging.

Results: 11 pts with median age 56 y (range 38-70) treated with H+R were evaluable for safety. Median # cycles was 3 (range 1+ to 12). Non-hematologic grade 3 toxicities in first 4 wks occurred in 3 of the first 9 pts: 1 pt had syncope associated with leucopenia/neutropenia and urinary infection; 1pt had mucositis which responded to dose reduction; 1 pt with known diabetes had grade 3 hyperglycemia, however, this was non-fasting. One pt had grade 3 leucopenia/neutropenia which responded to dose reduction. Grade 3 toxicities for 11 pts in all cycles were as follows: leucopenia/neutropenia (2 pts), non-fasting hyperglycemia (2 pts), syncope (1 pt), hypokalemia (1pt), hyponatremia (1 pt), mucositis (1 pt), rash (2 pts), nail changes (1 pt), thrombosis (1 pt). Infection (urine in 1 pt, skin in 1 pt), anemia (1pt), and elevated PTT (1 pt). One grade 4 non-fasting hyperglycemia occurred in a diabetic pt. LVEF dropped below normal limits and recovered subsequently in 2 pts. Nine pts had baseline and at least one subsequent evaluation for radiographic response by RECIST. Best response was unconfirmed partial response (PR) in 1 pt (8 cycles), stable disease (SD) in 5 pts (12, 6+,6, 3, and 2 cycles) and progression (PD) in 3pts. We combined analysis of AKT pathway markers from 12 baseline and 9 post therapy tissue samples collected on this trial and a phase I study of R +chemotherapy. There were high correlations between baseline AKT pathway markers (mTOR, PTEN, Akt, pAkt, S6K1 and pS6K1; (Spearman's rho-0.401-0.907). This correlation was lost in post therapy samples. Higher mean mTOR levels were seen in non-responders (PD) vs. responders (SD/PR) [p value=0.04]. Eight pts had CTC and CEC results, and were evaluable for response. Baseline CTC levels of &gt;5 cells/7.5 ml were seen in 2/2 pts with PD and 0/6 pts with SD/PR. There was no significant difference in CEC levels between responders and non-responders. Conclusion: R 6 mg daily appears to be well tolerated when combined with standard doses of H. PR in 1 pt and SD for ≥6 months was observed in 2 pts with prior progression on H based therapy. Baseline elevated mTOR level correlates with poor response to R based combinations. Post therapy change in marker expression suggests biologic effect of R.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-14-17.

Adult Rat Odontoblasts Lack Noxious Thermal Sensitivity

Dentin hypersensitivity is a common symptom treated in the dental clinic, yet the underlying cellular and molecular mechanisms are not clear. We hypothesized that odontoblasts detect noxious thermal stimuli by expressing temperature-sensing molecules, and investigated whether temperature-activated TRP channels (thermo-TRP channels), which are known to initiate temperature signaling, mediate temperature sensing in odontoblasts. mRNA expression of dentin sialophosphoprotein and collagenase type 1, odontoblast-specific proteins, was shown in acutely isolated adult rat odontoblasts by single-cell RT-PCR, while TRPV1, TRPV2, TRPM8, and TRPA1 were not detected. Application of noxious temperatures of 42°C and 12°C, as well as capsaicin, menthol, and icilin, agonists of thermo-TRP channels, failed to increase intracellular calcium concentration. Immunohistochemical study also revealed no expression of TRPV1. Thus, it is unlikely that odontoblasts serve as thermal sensors in teeth via thermo-TRP channels.

Modulation of CaV2.3 calcium channel currents by eugenol

Eugenol, a natural congener of capsaicin, is a routine analgesic agent in dentistry. We have recently demonstrated the inhibition of Ca(V)2.2 calcium channel and sodium channel currents to be molecular mechanisms underlying the analgesic effect of eugenol. We hypothesized that Ca(V)2.3 channels are also modulated by eugenol and investigated its mode of action using the whole-cell patch-clamp technique in a heterologous expression system. Eugenol inhibited calcium currents in the E52 cell line, stably expressing the human Ca(V)2.3 calcium channels, where TRPV1 is not endogenously expressed. The extent of current inhibition was not significantly different between naïve E52 cells and TRPV1-expressing E52 cells, suggesting no involvement of TRPV1. In contrast, TRPV1 activation is prerequisite for the inhibition of Ca(V)2.3 calcium channels by capsaicin. The results indicate that eugenol has mechanisms distinct from those of capsaicin for modulating Ca(V)2.3 channels. We suggest that inhibition of Ca(V)2.3 channels by eugenol might contribute to its analgesic effect.

The Centre for Health Informatics at the University of New South Wales - a Clinical Informatics Research Centre

Building a sustainable health system in the 21st Century will require the reinvention of much of the present day system, and the intelligent use of information and communication technologies (ICT) to deliver high quality, safe, efficient and affordable health care. The Centre for Health Informatics (CHI) is Australia’s largest academic research group in this emerging discipline.

Our research is underpinned by a planning process, based on different future scenarios for the health system, which helps us identify longer-term problems needing a sustained research effort. A research competency matrix is used to ensure that the Centre has the requisite core capabilities in the research methods and tools needed to pursue our research program.

The Centre’s work is internationally recognized for its contributions in the development of intelligent search systems to support evidence-based healthcare, developing evaluation methodologies for ICT, and in understanding how communication shapes the safety and quality of health care delivery. Centre researchers also are working on safety models and standards for ICT in healthcare, mining complex gene micro array, medical literature and medical record data, building health system simulation methods to model the impact of health policy changes, and developing novel computational methods to automate the diagnosis of 3-D medical images.

Any individual research group like CHI must necessarily focus on a few areas to allow it to develop sufficient research capacity to make novel and internationally significant contributions. As CHI approaches the end of its first decade, it is becoming clear that developing capacity becomes increasingly challenging as the research territory changes under our feet, and that the Centre will continue to evolve and shift its focus in the years to come.

The Centre for Health Informatics at the University of New South Wales--a clinical informatics research centre

OBJECTIVES

Building a sustainable health system in the 21st Century will require the reinvention of much of the present day system, and the intelligent use of information and communication technologies (ICT) to deliver high quality, safe, efficient and affordable health care. The Centre for Health Informatics (CHI) is Australia's largest academic research group in this emerging discipline.

METHODS

Our research is underpinned by a planning process, based on different future scenarios for the health system, which helps us identify longer-term problems needing a sustained research effort. A research competency matrix is used to ensure that the Centre has the requisite core capabilities in the research methods and tools needed to pursue our research program.

RESULTS

The Centre's work is internationally recognized for its contributions in the development of intelligent search systems to support evidence-based healthcare, developing evaluation methodologies for ICT, and in understanding how communication shapes the safety and quality of health care delivery. Centre researchers also are working on safety models and standards for ICT in healthcare, mining complex gene micro array, medical literature and medical record data, building health system simulation methods to model the impact of health policy changes, and developing novel computational methods to automate the diagnosis of 3-D medical images.

CONCLUSIONS

Any individual research group like CHI must necessarily focus on a few areas to allow it to develop sufficient research capacity to make novel and internationally significant contributions. As CHI approaches the end of its first decade, it is becoming clear that developing capacity becomes increasingly challenging as the research territory changes under our feet, and that the Centre will continue to evolve and shift its focus in the years to come.

Neoadjuvant dose-dense (DD) concurrent doxorubicin (A) and docetaxel (T) for stage III breast cancer (BC)

10721

Background: The addition of taxanes to anthracycline therapy results in improved disease-free survival (DFS) in the adjuvant setting, and increased pathologic complete response rates (pCR) in the neoadjuvant setting. DD chemotherapy improves DFS and overall survival (OS). We evaluated neoadjuvant DD concurrent AT. Methods: Eligible patients (pts) with stage III BC were treated with AT q 14 days at 1 of 3 dose levels; L1 = 60 mg/m2 for both drugs (4 pts), L2 = A 75 mg/m2 and T 60 mg/m2 (6 pts) or L3 = 75 mg/m2 for both drugs (7 pts) × 6 cycles with G-CSF. Dexrazoxane was given after a cumulative dose of 300 mg/m2 of A. Pts were stratified to post-operative moderate risk (ModR) (≥ partial response, ≤ 3 lymph nodes (LN)) and received adjuvant IV cyclophosphamide (C) 600 mg/m2, methotrexate 40 mg/m2, 5FU 600 mg/m2 IV q 21 d × 6 (CMF), or high risk (HiR) (≤ minor response +/or ≥ 4 LN) and received C 3 gm/m2 q 14 d x 3. Primary endpoints were clinical and pathologic response rates of neoadjuvant AT. Sample size was 42 pts to estimate pCR and provide 90% confidence the true incidence of severe toxicity is <10%. Results: 17 pts with stage III BC were enrolled between 2/1999 and 7/2001; accrual was halted after data on pre-operative trastuzumab were presented. Median age was 50 yrs [range: 34–69]. 3/17 pts (17.6%) had a pCR, and 3 pts had near pCR (residual foci ≤ 1mm), 4/17 (23.5%) had path (-) LN, 7/17 (41%) had a lumpectomy, 7/17 (41%) required dose reductions of AT due to grade 4 neutropenia (5 pts) and grade 3 neuropathy (2 pts). 3 pts required treatment cessation; 1 pt (L2) for prolonged neutropenic fever and 2 pts (L3) for decreased ejection fraction and for acute renal failure. 15 pts were ModR and received adjuvant CMF, 1/2 pts stratified to high dose C declined it and received CMF. Median follow-up is 63 months [range: 28–80] with 13/17 (76.5%) pts surviving, and 12/17 (70.5%) pts surviving and free of disease. Conclusion: Neoadjuvant DD AT every 2 weeks is well-tolerated, with promising activity and survival in locally advanced BC.

[Table: see text]

HERP, a new primary target of Notch regulated by ligand binding

Notch signaling dictates cell fate and critically influences cell proliferation, differentiation, and apoptosis in metazoans. Ligand binding initiates the signal through regulated intramembrane proteolysis of a transmembrane Notch receptor which releases the signal-transducing Notch intracellular domain (NICD). The HES/E(spl) gene family is a primary target of Notch and thus far the only known Notch effector. A newly isolated HERP family, a HES-related basic helix-loop-helix protein family, has been proposed as a potential target of Notch, based on its induction following NICD overexpression. However, NICD is physiologically maintained at an extremely low level that typically escapes detection, and therefore, nonregulated overexpression of NICD-as in transient transfection-has the potential of generating cellular responses of little physiological relevance. Indeed, a constitutively active NICD indiscriminately up-regulates expression of both HERP1 and HERP2 mRNAs. However, physiological Notch stimulation through ligand binding results in the selective induction of HERP2 but not HERP1 mRNA and causes only marginal up-regulation of HES1 mRNA. Importantly, HERP2 is an immediate target gene of Notch signaling since HERP2 mRNA expression is induced even in the absence of de novo protein synthesis. HERP2 mRNA induction is accompanied by specific expression of HERP2 protein in the nucleus. Furthermore, using RBP-Jk-deficient cells, we show that an RBP-Jk protein, a transcription factor that directly activates HES/E(spl) transcription, also is essential for HERP2 mRNA expression and that expression of exogenous RBP-Jk is sufficient to rescue HERP2 mRNA expression. These data establish that HERP2 is a novel primary target gene of Notch that, together with HES, may effect diverse biological activities of Notch.

HERP, a novel heterodimer partner of HES/E(spl) in Notch signaling

HERP1 and -2 are members of a new basic helix-loop-helix (bHLH) protein family closely related to HES/E(spl), the only previously known Notch effector. Like that of HES, HERP mRNA expression is directly up-regulated by Notch ligand binding without de novo protein synthesis. HES and HERP are individually expressed in certain cells, but they are also coexpressed within single cells after Notch stimulation. Here, we show that HERP has intrinsic transcriptional repression activity. Transcriptional repression by HES/E(spl) entails the recruitment of the corepressor TLE/Groucho via a conserved WRPW motif, whereas unexpectedly the corresponding-but modified-tetrapeptide motif in HERP confers marginal repression. Rather, HERP uses its bHLH domain to recruit the mSin3 complex containing histone deacetylase HDAC1 and an additional corepressor, N-CoR, to mediate repression. HES and HERP homodimers bind similar DNA sequences, but with distinct sequence preferences, and they repress transcription from specific DNA binding sites. Importantly, HES and HERP associate with each other in solution and form a stable HES-HERP heterodimer upon DNA binding. HES-HERP heterodimers have both a greater DNA binding activity and a stronger repression activity than do the respective homodimers. Thus, Notch signaling relies on cooperation between HES and HERP, two transcriptional repressors with distinctive repression mechanisms which, either as homo- or as heterodimers, regulate target gene expression.

Mouse Models of Human Chromosomal Translocations and Approaches to Cancer Therapy

Cancer arises because of genetic changes in somatic cells, eventually giving rise to overt malignancy. Principle among genetic changes found in tumor cells are chromosomal translocations which give rise to fusion genes or enforced oncogene expression. These mutations are tumor-specific and result in production of tumor-specific mRNAs and proteins and are attractive targets for therapy. Also, in acute leukemias, many of these molecules are transcription regulators which involve cell-type-specific complexes, offering an alternative therapy via interfering with protein-protein interaction. We are studying these various features of tumor cells to evaluate new therapeutic methods. We describe a mouse model of de novo chromosomal translocations using the Cre-loxP system in which interchromosomal recombination occurs between the Mll and Af9 genes. We are also developing other in vivo methods designed, like the Cre-loxP system, to emulate the effects of these chromosomal abnormalities in human tumors. In addition, we describe new technologies to facilitate the intracellular targeting of fusion mRNAs and proteins resulting from such chromosomal translocations. These include a masked antisense RNA method with the ability to discriminate between closely related RNA targets and the selection and use of intracellular antibodies to bind to target proteins in vivo and cause cell death. These approaches should also be adaptable to targeting point mutations or to differentially expressed tumor-associated proteins. We hope to develop therapeutic approaches for use in cancer therapy after testing their efficacy in our mouse models of human cancer.

Proteasome-mediated degradation of the coactivator p300 impairs cardiac transcription

The transcription of tissue-specific genes is controlled by regulatory factors and cofactors and is suppressed in cardiac cells by the antineoplastic agent doxorubicin. Here we show that exposure of cultured cardiomyocytes to doxorubicin resulted in the rapid depletion of transcripts for MEF2C, dHAND, and NKX2.5, three pivotal regulators of cardiac gene expression. Delivery of exogenous p300, a coactivator of MEF2C and NKX2.5 in cardiomyocytes, restored cardiac transcription despite the presence of doxorubicin. Furthermore, p300 also restored the accumulation of transcripts for MEF2C itself. Importantly, cardiocytes exposed to doxorubicin displayed reduced levels of p300 proteins. This was not due to alterations in the level of p300 transcripts; rather, and surprisingly, doxorubicin promoted selective degradation of p300 mediated by the 26S-proteasome machinery. Doxorubicin had no effect on the general level of ubiquitinated proteins or on the levels of beta-catenin, a protein known to be degraded by proteasome-mediated degradation. These results provide evidence for a new mechanism of transcriptional repression caused by doxorubicin in which the selective degradation of p300 results in reduced p300-dependent transcription, including production of MEF2C mRNA.

Intramyocardial injection of DNA encoding vascular endothelial growth factor in a myocardial infarction model

In a previous study, we observed that one injection of 500 microg of DNA for the plasmid encoding for vascular endothelial growth factor (ph VEGF(165)) into one site in a rat myocardial infarction model resulted in neovascularization confined to angiomatous structures that did not contribute to regional myocardial blood flow. The purpose of the present study was to determine whether a lower dose (125 microg DNA), which is the same as that being used in some clinical trials, injected into four separate sites could enhance collateral flow and vascularity to the ischemic bed without inducing angiomas. Rats received injections of 125 microg DNA of the plasmid encoding phVEGF(165) or control DNA at four separate sites within the anterior free wall of the left ventricle (LV) supplied by the left coronary artery. The left coronary artery was ligated and hearts analyzed at 4 weeks. In vitro studies confirmed that the phVEGF(165) used was capable of producing VEGF polypeptide in mammalian cells. The infarct size (percentage of endocardial circumference that infarcted) was similar in controls (42+/-6%) and treated hearts (39+/-7%); the LV cavity area did not differ between groups. The number of vascular structures per high-power field within the infarct scar was 10.50+/-0.68 in controls and 10.00+/-0.85 in phVEGF(165)-treated rats. Relative regional myocardial blood flow determined by radioactive microspheres and expressed as a ratio of radioactive counts within the scar divided by radioactive counts in the noninfarcted ventricular septum was similar in control (0.74+/-0.25) and treated hearts (0.88+/-0.30) (p=not significant). No angiomatous structures were observed. Injections of 125 microg of DNA of phVEGF(165) into myocardium to become ischemic had no effect on infarct size or LV cavity size. Unlike higher doses of 500 microg of DNA, it did not cause gross angiomatous structures; however, it failed to improve neovascularization or regional myocardial blood flow in this rodent model of acute myocardial infarction.

Acetylation of MyoD directed by PCAF is necessary for the execution of the muscle program

p300/CBP and PCAF coactivators have acetyltransferase activities and regulate transcription, cell cycle progression, and differentiation. They are both required for MyoD activity and muscle differentiation. Nevertheless, their roles must be different since the acetyltransferase activity of PCAF but not of p300 is involved in controlling myogenic transcription and differentiation. Here, we provide a molecular explanation of this phenomenon and report that MyoD is directly acetylated by PCAF at evolutionarily conserved lysines. Acetylated MyoD displays an increased affinity for its DNA target. Importantly, conservative substitutions of acetylated lysines with nonacetylatable arginines impair the ability of MyoD to stimulate transcription and to induce muscle conversion indicating that acetylation of MyoD is functionally critical.

The effect of chromosomal translocations in acute leukemias: the LMO2 paradigm in transcription and development

Two general features have emerged about genes that are activated after chromosomal translocations in acute forms of cancer. The protein products of these genes are transcription regulators and are involved in developmental processes, and it seems that the subversion of these normal functions accounts for their role in tumorigenesis. The features of the LMO family of genes, which encode LIM-domain proteins involved in T-cell acute leukemia through chromosomal translocations, typify these abnormal functions in tumorigenesis. For example, the LMO2 protein is involved in the formation of multimeric DNA-binding complexes, which may vary in composition at different stages of hematopoiesis and function to control differentiation of specific lineages. In T cells, enforced expression of Lmo2 causes aberrant protein complex formation that primarily seems to hinder the T-cell differentiation program. These observations underscore the conclusion that protein-protein interaction (in this case, through the LIM domain) is a key determinant in tumorigenesis. Furthermore, the study of chromosomal translocations as naturally occurring mutations has been informative about mechanisms in hematopoiesis as well as in tumor etiology.

A new pathway for mitogen-dependent cdk2 regulation uncovered in p27(Kip1)-deficient cells

BACKGROUND

The ability of cyclin-dependent kinases (CDKs) to promote cell proliferation is opposed by cyclin-dependent kinase inhibitors (CKIs), proteins that bind tightly to cyclin-CDK complexes and block the phosphorylation of exogenous substrates. Mice with targeted CKI gene deletions have only subtle proliferative abnormalities, however, and cells prepared from these mice seem remarkably normal when grown in vitro. One explanation may be the operation of compensatory pathways that control CDK activity and cell proliferation when normal pathways are inactivated. We have used mice lacking the CKIs p21(Cip1) and p27(Kip1) to investigate this issue, specifically with respect to CDK regulation by mitogens.

RESULTS

We show that p27 is the major inhibitor of Cdk2 activity in mitogen-starved wild-type murine embryonic fibroblasts (MEFs). Nevertheless, inactivation of the cyclin E-Cdk2 complex in response to mitogen starvation occurs normally in MEFs that have a homozygous deletion of the p27 gene. Moreover, CDK regulation by mitogens is also not affected by the absence of both p27 and p21. A titratable Cdk2 inhibitor compensates for the absence of both CKIs, and we identify this inhibitor as p130, a protein related to the retinoblastoma gene product Rb. Thus, cyclin E-Cdk2 kinase activity cannot be inhibited by mitogen starvation of MEFs that lack both p27 and p130. In addition, cell types that naturally express low amounts of p130, such as T lymphocytes, are completely dependent on p27 for regulation of the cyclin E-Cdk2 complex by mitogens.

CONCLUSIONS

Inhibition of Cdk2 activity in mitogen-starved fibroblasts is usually performed by the CKI p27, and to a minor extent by p21. Remarkably p130, a protein in the Rb family that is not related to either p21 or p27, will directly substitute for the CKIs and restore normal CDK regulation by mitogens in cells lacking both p27 and p21. This compensatory pathway may be important in settings in which CKIs are not expressed at standard levels, as is the case in many human tumors.