The effect of an exopolysaccharide probiotic molecule from Bacillus subtilis on breast cancer cells

Introduction

Many well-known risk factors for breast cancer are associated with dysbiosis (an aberrant microbiome). However, how bacterial products modulate cancer are poorly understood. In this study, we investigated the effect of an exopolysaccharide (EPS) produced by the commensal bacterium Bacillus subtilis on breast cancer phenotypes. Although B. subtilis is commonly included in probiotic preparations and its EPS protects against inflammatory diseases, it was virtually unknown whether B. subtilis-derived EPS affects cancer.

Methods

This work investigated effects of EPS on phenotypes of breast cancer cells as a cancer model. The phenotypes included proliferation, mammosphere formation, cell migration, and tumor growth in two immune compromised mouse models. RNA sequencing was performed on RNA from four breast cancer cells treated with PBS or EPS. IKKβ or STAT1 signaling was assessed using pharmacologic or RNAi-mediated knock down approaches.

Results

Short-term treatment with EPS inhibited proliferation of certain breast cancer cells (T47D, MDA-MB-468, HCC1428, MDA-MB-453) while having little effect on others (MCF-7, MDA-MB-231, BT549, ZR-75-30). EPS induced G1/G0 cell cycle arrest of T47D cells while increasing apoptosis of MDA-MB-468 cells. EPS also enhanced aggressive phenotypes in T47D cells including cell migration and cancer stem cell survival. Long-term treatment with EPS (months) led to resistance in vitro and promoted tumor growth in immunocompromised mice. RNA-sequence analysis showed that EPS increased expression of pro-inflammatory pathways including STAT1 and NF-κB. IKKβ and/or STAT1 signaling was necessary for EPS to modulate phenotypes of EPS sensitive breast cancer cells.

Discussion

These results demonstrate a multifaceted role for an EPS molecule secreted by the probiotic bacterium B. subtilis on breast cancer cell phenotypes. These results warrant future studies in immune competent mice and different cancer models to fully understand potential benefits and/or side effects of long-term use of probiotics.

Barriers and facilitators of weight bearing after hip fracture surgery among older adults. A scoping review

PURPOSE

This scoping review aimed to synthesise the available evidence on barriers and facilitators of weight bearing after hip fracture surgery in older adults.

METHODS

Published (Cochrane Central, MEDLINE, EMBASE, CINAHL, and PEDro) and unpublished (Global Health, EThOS, WorldCat dissertation and thesis, ClinicalTrials.gov , OpenAIRE, DART-Europe) evidence was electronically searched from database inception to 29 March 2022. Barriers and facilitators of weight bearing were extracted and synthesised into patient, process (non-surgical), process (surgical), and structure-related barriers/facilitators using a narrative review approach.

RESULTS

In total, 5594 were identified from the primary search strategy, 1314 duplicates were removed, 3769 were excluded on title and abstract screening, and 442 were excluded on full-text screening. In total, 69 studies (all from published literature sources) detailing 47 barriers and/or facilitators of weight bearing were included. Of barriers/facilitators identified, 27 were patient-, 8 non-surgical process-, 8 surgical process-, and 4 structure-related. Patient facilitators included anticoagulant, home discharge, and aid at discharge. Barriers included preoperative dementia and delirium, postoperative delirium, pressure sores, indoor falls, ventilator dependence, haematocrit < 36%, systemic sepsis, and acute renal failure. Non-surgical process facilitators included early surgery, early mobilisation, complete medical co-management, in-hospital rehabilitation, and patient-recorded nurses' notes. Barriers included increased operative time and standardised hip fracture care. Surgical process facilitators favoured intramedullary fixations and arthroplasty over extramedullary fixation. Structure facilitators favoured more recent years and different healthcare systems. Barriers included pre-holiday surgery and admissions in the first quarter of the year.

CONCLUSION

Most patient/surgery-related barriers/facilitators may inform future risk stratification. Future research should examine additional process/structure barriers and facilitators amenable to intervention. Furthermore, patient barriers/facilitators need to be investigated by replicating the studies identified and augmenting them with more specific details on weight bearing outcomes.

Abstract P3-11-01: Increasing DAXX Expression in ER+ Breast Cancer Cells to Overcome Endocrine Therapy Resistance

Background: New treatment paradigms are needed to overcome resistance to endocrine therapy (ET; tamoxifen or aromatase inhibitors, AI) in ER+ breast cancer (BC). ET resistance is due to survival of breast cancer stem cells (BCSCs) that contribute to relapse of ER+ BC. Notch signaling drives BCSCs. In order to identify Notch specific biomarkers for the purpose of patient selection for anti-Notch therapy, we conducted a pre-surgical biomarker window study combining ET plus MK-0752, a -secretase inhibitor (GSI). Death Associated Protein 6 (DAXX) was discovered to be a novel Notch1 target gene and necessary for GSI-mediated inhibition of BCSCs. Subsequently, we found that DAXX alone was sufficient to inhibit BCSCs. In this current study, we investigated the mechanism by which high DAXX expression inhibited growth of ET resistant ER+ BC cells in vitro and in vivo. Methods: Isogenic ER+ BC cell lines (parental MCF-7, ET resistant MCF-7/5C, parental T47D, and ET resistant T47D-ED) were used. Cells were cultured in estrogen-deprived medium for more than 1 year to mimic AI use. DAXX was depleted using siRNA or overexpressed using a pCMV-expression vector. Bulk cell proliferation was analyzed in response to estrogen depletion or increasing concentrations of 17-estradiol. BCSC survival was measured using the mammosphere-forming assay. Tumor onset and burden were measured by injecting DAXX-expressing or depleted mammospheres into mammary fat pads of female, athymic nude mice. Recurrence of an ER+ PDX tumor (BCM 5097) was measured after withdrawal of estrogen. RNA sequencing identified enriched genes and pathways that required DAXX. Based on these results, cell death was assessed using Annexin V/7-AAD flow cytometry, PARP-1 and Caspase 8 cleavage, phosphorylation of JNK, and expression of apoptotic protein regulators, BIM, BAX, Bcl-2, and Bcl-xL. JNK signaling was inhibited using SB600125. Results: Estradiol stimulated proliferation of parental, ER+ MCF-7 and T47D cells. In contrast, estradiol inhibited proliferation of isogenic ET resistant MCF-7/5C and T47D-ED cells in a concentration and ER-dependent manner. Estradiol induced the DAXX protein in both ET sensitive and resistant cells. DAXX was required for BCSC survival in ET sensitive cells. However, once ER+ cells acquired resistance to ET, DAXX was necessary and sufficient to inhibit both bulk cell proliferation and BCSC survival, suggesting that increasing DAXX might be a novel approach to overcome ET resistance. In mice, high DAXX expression significantly inhibited tumor onset and burden of ET resistant tumors compared to DAXX-depleted tumors. Low DAXX expression was significantly associated with recurrence of an ER+ PDX tumor (BCM 5097) after withdrawal of estrogen. RNA sequencing revealed that DAXX activated an anti-neoplastic gene signature, including transcription factors that regulate cell death genes including the Bcl2-family. DAXX was required for high BIM expression and low levels of Bcl-xL. DAXX was necessary and sufficient to induce apoptosis, PARP-1 cleavage, and phosphorylation of JNK in ET resistant cells. A selective JNK inhibitor, SB600125 rescued DAXX-mediated inhibition of ET resistant bulk cell proliferation and BCSC survival, suggesting that high DAXX expression activates JNK signaling to regulate apoptotic proteins to induce cell death of BCSCs-derived from ET resistant BC. Conclusions: Expressing high DAXX levels is a potent method to inhibit ET-resistant BC cell proliferation and BCSC survival. The mechanism by which DAXX inhibits ET-resistant BC is through activation of JNK signaling, regulation of pro-apoptotic genes, and induction of apoptosis. The translational impact of this research is to identify novel agents that can increase DAXX expression and test them pre-clinically and in clinical trials for patients with ET-resistant breast cancer.

Citation Format: Clodia Osipo, Kathy S. Albain, Daniel Peiffer, Debra Wyatt. Increasing DAXX Expression in ER+ Breast Cancer Cells to Overcome Endocrine Therapy Resistance [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-11-01.

659 PATIENT PERSPECTIVES OF RECOVERY AFTER HIP FRACTURE: A SYSTEMATIC REVIEW AND QUALITATIVE SYNTHESIS

Background

Recovery is multidimensional highlighted by a wealth of qualitative evidence published on patient perspectives of recovery after hip fracture. The purpose of the current review is to synthesize this evidence of patients’ perspectives of recovery after hip fracture across the care continuum.

Methods

A systematic search was conducted, focusing on qualitative data from hip fracture patients. Two authors independently screened title and abstracts, full texts, completed extraction, and quality appraisal. Themes for this review were generated using a thematic synthesis of data from original studies.

Results

Fourteen qualitative studies were included in this review. The overall quality of included studies was high. We identified four review themes: defining recovery, feelings of vulnerability, driving recovery, and reliance on support. Patients considered recovery as a return to prefracture activities or ‘normal’ enabling independence. Feelings of vulnerability were observed for patients irrespective of the time since hip fracture and only diminished when recovery of function and activities enabled participation in valued activities e.g. outdoor mobility. Participants expressed a desire to actively engage in recovery with realistic expectations and benefits of meaningful feedback reported. Reliance on healthcare support varied by time since fracture with patients highlighting a greater reliance on professional support in the early versus late stages of recovery. Reliance on social support persisted until recovery was perceived to have been achieved and was highlighted more for participants who were living alone.

Conclusion

Patient perspectives of recovery enhance previous understanding of recovery domains. Patient perspectives highlighted hip fracture as a major life event which requires health professional and social support to overcome feelings of vulnerability and enable active engagement in recovery. Future research should investigate the recovery perspective of patients with cognitive impairment, and further consider perspectives on recovery from carers.

Abstract P3-05-03: KMT2D as a novel therapeutic target for HER2+ breast cancers

Background: Breast cancer is the second leading cause of cancer-related deaths among women in the US. Major factors that contribute to breast cancer carcinogenesis include disruptions in both genetic and epigenetic processes. Histone modifications and DNA-methylation are common epigenetic changes that have been implicated in several breast cancers, including an aggressive subset known as human epidermal growth factor receptor 2 (HER2+) breast cancers. One prognostic marker for poor survival in women with HER2+ breast cancer is high RNA expression of the critical epigenetic regulator, Histone-lysine methyltransferase 2D (KMT2D). KMT2D belongs to a family of histone modifying proteins which plays an essential role in regulating developmental processes. Specifically, KMT2D is a histone methyltransferase that monomethylates histone 3 lysine 4 at enhancers throughout the genome and is required for transcriptional activation. Interestingly, in HER2+ cells (BT474), KMT2D mRNA was found to be significantly increased in stem-like tumor initiating cells (TICs) compared to bulk cells. BT474 cells that have acquired resistance to trastuzumab (BTR) from prolonged treatment express higher levels of KMT2D than those of the isogenic parental sensitive cells (BTS). Furthermore, siRNA-specific knockdown of KMT2D significantly decreased bulk cell proliferation in both BTS and BTR cells, and significantly inhibited TIC survival in BTS cells. Thus, we hypothesized that KMT2D is a critical epigenetic regulator that contributes to resistance by promoting bulk cell proliferation and TIC survival. Methods: RNA-sequencing was performed in BTS and BTR cells-expressing or depleted for KMT2D. Differentially regulated genes were identified and pathway analysis was performed. Chromatin immunoprecipitation (ChIP) PCR and sequencing were performed to identify novel KMT2D-bound regions in both BTS and BTR cells. SiRNA induced silencing was also utilized to study various gene functions in BT474 cells. Results: We identified and confirmed by RT-qPCR several differentially expressed genes that were positively and negatively regulated by KMT2D, suggesting they may be critical direct targets of KMT2D. One gene, ITGB6, encodes for integrin subunit beta 6 and was found to be decreased upon KMT2D depletion. ITGB6 regulates multiple processes which contribute to cancer progression and metastases, including cellular proliferation and epithelial-mesenchymal transition. Similar to KMT2D knockdown, ITGB6 knockdown resulted in decreased BTS and BTR bulk cell proliferation and a reduction in TICs. Interestingly, KMT2D enrichment at an ITGB6 enhancer region was lower in resistant cells compared to sensitive cells. Future studies will include knockdown of KMT2D with simultaneous rescue of wild type or a mutant of ITGB6 to determine if KMT2D-mediated increase in ITGB6 is required for HER2+ cell growth and/or TIC survival. Furthermore, our data also suggests an anti-apoptotic and cell-cell adhesion role for KMT2D, which may in part be due to its direct effects on ITGB6. Additional future studies will investigate the mechanism of how KMT2D regulates its target genes through ChIP-sequencing analysis as well as studies to evaluate KMT2D’s role in vivo. Conclusions: Our results suggest a critical role for KMT2D in HER2+ breast cancer progression, and may yield novel therapeutic targets and pathways for the treatment of HER2+ breast cancers.

Citation Format: Emily Ma, Andrei Zlobin, Debra Wyatt, Jeffrey Ng, Andrew Dingwall, Clodia Osipo. KMT2D as a novel therapeutic target for HER2+ breast cancers [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-05-03.

Abstract P1-08-22: The role of DAXX as a critical growth regulator of triple negative breast cancer

Background: Triple negative breast cancer (TNBC) is a heterogeneous disease that frequently presents at a metastatic stage or upon initial early stage diagnosis, and may recur quickly. Treatment options are limited outside of cytotoxic chemotherapy in the adjuvant or metastatic setting and there is an immediate need to identify and validate novel biomarkers that predict sensitivity to chemotherapy. Previously, it was shown that the pro-apoptotic protein DAXX is required for paclitaxel-mediated breast cancer cell death. Based on these data and our recent discoveries that DAXX is a potent inhibitor of breast cancer stem cells in ER+ breast cancer (Peiffer et al., Cancer Res. 2019; Peiffer et al., NPJ Breast Cancer. 2020), we next explored the role of DAXX in TNBC. We found that high DAXX expression in TNBC cells regulates cell proliferation and activities of PARP-1 and JNK; two pathways required for cell death. The goals of the current work were to investigate the mechanism by which DAXX regulates proliferation at the level of PARP-1 and/or JNK and test if DAXX expression predicts sensitivity to carboplatin, paclitaxel, doxorubicin, the PARP-1 inhibitor olaparib, or the JNK inhibitor SP600125 in TNBC cells. Methods: Proliferation and cell cycle analysis were performed in three TNBC cell lines (MDA-MB-231, BT549, and MDA-MB-468) under DAXX expression and depletion conditions using an siRNA approach. Sensitivity to carboplatin, paclitaxel, and doxorubicin was determined by measuring proliferation in a dose-dependent manner. PARP-1 activity was assessed by detecting global protein PARylation levels using Western blotting. JNK activation was analyzed by measuring phosphorylated JNK levels. A JNK inhibitor (SP600125) was used to determine if JNK signaling was responsible for restricting cell proliferation and if DAXX was required for the elevated JNK activity. Olaparib was used to assess the role of PARP-1 activation in DAXX-depleted cells. Results: The TNBC cell lines expressed high levels of DAXX. Depletion of DAXX increased cell proliferation by promoting cell cycle progression through the S-phase. The consequence of this increased cell proliferation was decreased sensitivity to carboplatin and paclitaxel, but not to doxorubicin. Mechanistically, at least one chemotherapeutic agent, carboplatin induced JNK activation and DAXX was required for the increased JNK activity. The JNK inhibitor (SP600125) partially reversed resistance to carboplatin in DAXX-depleted cells. Additionally, genetic knockdown of DAXX resulted in elevated PARP-1 activity as measured by global PARylation of proteins. PARP-1 blockade using olaparib also partially reversed resistance to carboplatin in DAXX-depleted cells. Conclusions: These results suggest that DAXX is a critical growth regulator and predictor of response to carboplatin and paclitaxel in triple negative breast cancer cells. DAXX is necessary to activate the JNK pathway in response to carboplatin and it is this carboplatin-mediated JNK signaling that inhibits cell proliferation. Furthermore, DAXX limits PARP-1 activity and is necessary for increased sensitivity to carboplatin or paclitaxel. Data herein support assessing DAXX expression in triple negative tumors to determine if high DAXX expression predicts increased sensitivity to carboplatin, paclitaxel, and if DAXX-low expressing TNBC cells require addition of a JNK or PARP-1 inhibitor.

Citation Format: Clodia Osipo, Debra Wyatt, Michelle Fernandez, Daniel S Peiffer, Kathy S Albain. The role of DAXX as a critical growth regulator of triple negative breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-08-22.

Abstract 1859: Elucidating the role of KMT2D as a novel therapeutic target for resistant HER2+ breast cancer

HER2 targeted agents have improved clinical outcomes for women with HER2+ breast cancer. However, drug resistance remains a critical challenge for curing HER2+ disease. Cancer stem cells (CSCs)-enriched during anti-HER2 therapy promote resistance and recurrence. Therefore, novel targets that drive survival of CSCs are needed. Recently, the histone-lysine N-methyltransferase 2D (KMT2D) has been shown to be a prognostic marker for poor recurrence free survival in women with HER2+ breast cancer. Preliminary data showed that KMT2D RNA was increased in HER2+ CSC-enriched mammospheres compared to bulk cells. Further, KMT2D protein is increased in resistant compared to sensitive cells. These data suggest that KMT2D is necessary for survival of CSCs and resistance to anti-HER2 therapy. To address this hypothesis, RNAi-mediated knockdown of KMT2D was performed in trastuzumab sensitive and resistant cells. KMT2D depletion in sensitive cells resulted in almost complete blockade of proliferation in 2-D culture and CSC survival in 3-D culture. In contrast, proliferation and CSC survival was only moderately inhibited by KMT2D depletion in resistant cells. ChIP studies confirmed that KMT2D is enriched on the MYC enhancer in sensitive cells but only moderately in resistant cells. Based on these data, KMT2D is necessary for growth of HER2+ breast cancer and is possibly inactivated during acquisition of resistance. To determine the mechanism, RNA sequencing was performed in both sensitive and resistance cells expressing or depleted for KMT2D. Several differentially expressed genes that were positively or negatively regulated by KMT2D were identified. Specifically, transcript levels of ITGB6 and CLIC3 were decreased upon KMT2D knockdown, while PGR and AR transcripts were increased. Initial results showed that ITGB6 depletion resulted in decreased bulk cell proliferation and survival of CSCs similar to KMT2D knockdown. These results suggest that ITGB6 could be a direct target gene of KMT2D and thus mediates the phenotypic effects of KMT2D. Overall, our results suggest that KMT2D is necessary for both proliferation and CSC survival in HER2+ breast cancer sensitive to anti-HER2 therapy and a combination approach of targeting both HER2 and KMT2D could prevent enrichment of CSCs and acquired resistance.

Citation Format: EMILY MA, Andrei Zlobin, Debra Wyatt, Jeffrey Ng, Andrew Dingwall, Clodia Osipo. Elucidating the role of KMT2D as a novel therapeutic target for resistant HER2+ breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1859.

DAXX-inducing phytoestrogens inhibit ER+ tumor initiating cells and delay tumor development

Recurrence of estrogen receptor (ER)-positive breast tumors despite curative-intent adjuvant therapy is thought to be due to enrichment of tumor initiating cells (TIC) during endocrine therapy (ET). Recently, it was identified that by antagonizing the ER, ET promotes rapid degradation of the death-associated factor 6 (DAXX) protein, which is necessary and sufficient to potently inhibit TICs. Thus, the goal of the current study was to identify a DAXX-inducing agent to inhibit TICs and prevent proliferation of the tumor. Phytoestrogens (naringenin, resveratrol, genistein, apigenin, and quercetin) were screened for DAXX protein expression, anti-TIC and anti-proliferative efficacy in vitro and in vivo. Specific DAXX-inducing phytoestrogens were tested to assess selectivity towards ERα and/or ERβ. Results showed that phytoestrogens tested induced DAXX protein expression and inhibited survival of TICs from ER+ MCF-7 and T47D cells. Only naringenin, resveratrol, and quercetin did not stimulate total cell proliferation. Naringenin, resveratrol, but not quercetin inhibited survival of TICs in vitro and in vivo in a DAXX-dependent manner. Naringenin-induced DAXX protein expression and inhibition of TICs seemed to be more selective towards ERβ while resveratrol was more selective through ERα. Naringenin or resveratrol inhibited the rate of tumor initiation and rate of tumor growth in a DAXX-dependent manner. These results suggest that a therapeutic approach using a phytoestrogen to induce DAXX protein expression could potently inhibit TICs within a tumor to delay or prevent tumor initiation. Therefore, a DAXX-promoting phytoestrogen should be explored for prevention of tumor progression in advanced disease and relapse in the adjuvant setting.

OP0205 PHASE I STUDY OF D-0120, A NOVEL URAT1 INHIBITOR IN CLINICAL DEVELOPMENT FOR HYPERURICEMIA AND GOUT

Background:

D-0120 is a novel oral selective uric acid transporter (URAT1) inhibitor being developed for the treatment of hyperuricemia and gout by blocking the reabsorption of uric acid (UA) within the renal proximal tubule, thereby reducing serum uric acid concentrations. As a novel URAT1 inhibitor, D-0120 is anticipated to have more potent serum UA reducing effect than the approved URAT1 inhibitor lesinurad, but with less toxicity and wider therapeutic window. The pharmacological potential of D-0120 for the treatment of hyperuricemia and gout was demonstrated in preclinical studies. The results of the in vitro hURAT1 expressed CHO cell model showed that the inhibitory activity of D-0120 is 150-fold more potent than lesinurad and slightly more potent than verinurad.

Objectives:

The purpose of this dose escalation study is to evaluate the safety and tolerability of D-0120 in multiple ascending doses in healthy volunteer, to characterize the pharmacokinetics (PK) of D-0120 and to assess pharmacodynamic (PD) effects and determine the drug-drug interaction (DDI) effect of febuxostat and D-0120 in healthy volunteers.

Methods:

This is a randomized, double blind, multiple ascending doses Phase I study of D-0120 in healthy volunteers conducted at one site. Thirty-two healthy eligible volunteers with serum uric acid level ≥ 4.5 mg/dL but within normal range at screening were enrolled and dosed with D-0120 within 4 different single agent cohorts for a period of 7 days. Each cohort had 8 subjects randomized at 3:1 ratio for D-0120:placebo. A fifth cohort of 8 healthy eligible volunteers were enrolled and dosed with 5 mg of D-0120 in combination with 40 mg of febuxostat over a period of 9 days. Evaluation of safety, PK and PD was conducted at various timepoints while the patients were in confinement. Further safety evaluation took place on Day 14. A Safety Review Committee reviewed safety, PK and PD data for each cohort of D-0120 dose level (2.5 mg, 5 mg, 10 mg, 20 mg) as well as when D-0120 5 mg was combined with 40 mg febuxostat. PK evaluation for multiple dose parameters included AUC0-τ, Cmax, Cmin, Tmax and Fl.

Results:

Dose escalation of D-0120 from 2.5 mg/day to 20 mg/day was completed without any dose limiting toxicities. Most AEs occurred during the study were mild to moderate in severity and did not require any treatment before resolution. There was no SAE and no dose reduction during the treatment period. The pharmacokinetic (PK) evaluation of ascending dose levels of D-0120 suggested a dose proportional increase in drug exposure and there was no significant change of PK profile between Day 1 and Day 7 of dosing. For pharmacodynamic (PD) evaluation, the serum uric acid (UA) levels before and after D-0120 dosing was evaluated on multiple days. The UA reduction effect achieved maximum at about 4-8 hours after dosing and the effect lasted for at least 24 hours. After the 7-day dosing period, the mean percentage of UA reduction from baseline showed an increasing trend as the dose level increased.

More detailed safety, PK and PD data from multiple D-0120 dose cohorts and D-0120/febuxostat combination cohort will be presented at the meeting.

Conclusion:

The oral daily administration of a novel URAT1 inhibitor, D-0120, in healthy volunteers for 7 days was well tolerated at dose levels from 2.5 mg/day to 20 mg/day. The PK profile demonstrated a dose proportional increase. D-0120 administration for 7 days resulted in significant reduction of serum UA levels. Further evaluation of this novel agent in longer treatment period and in patients with hyperuricemia and/or gout is warranted.

References:

Not Applicable.

Disclosure of Interests:

Ling Zhang Employee of: INVENTISBIO, David Wyatt: None declared, Kathryn Stazzone Employee of: INVENTISBIO, Zhe Shi Employee of: INVENTISBIO, Yaolin Wang Employee of: INVENTISBIO

DAXX Suppresses Tumor-Initiating Cells in Estrogen Receptor-Positive Breast Cancer Following Endocrine Therapy

Estrogen receptor (ER)-positive breast cancer recurrence is thought to be driven by tumor-initiating cells (TIC). TICs are enriched by endocrine therapy through NOTCH signaling. Side effects have limited clinical trial testing of NOTCH-targeted therapies. Death-associated factor 6 (DAXX) is a newly identified marker whose RNA expression inversely correlates with NOTCH in human ER⁺ breast tumor samples. In this study, knockdown and overexpression approaches were used to investigate the role of DAXX on stem/pluripotent gene expression, TIC survival in vitro, and TIC frequency in vivo, and the mechanism by which DAXX suppresses TICs in ER⁺ breast cancer. 17β-Estradiol (E₂)-mediated ER activation stabilized the DAXX protein, which was required for repressing stem/pluripotent genes (NOTCH4, SOX2, OCT4, NANOG, and ALDH1A1), and TICs in vitro and in vivo. Conversely, endocrine therapy promoted rapid protein depletion due to increased proteasome activity. DAXX was enriched at promoters of stem/pluripotent genes, which was lost with endocrine therapy. Ectopic expression of DAXX decreased stem/pluripotent gene transcripts to levels similar to E₂ treatment. DAXX-mediated repression of stem/pluripotent genes and suppression of TICs was dependent on DNMT1. DAXX or DNMT1 was necessary to inhibit methylation of CpGs within the SOX2 promoter and moderately within the gene body of NOTCH4, NOTCH activation, and TIC survival. E₂-mediated stabilization of DAXX was necessary and sufficient to repress stem/pluripotent genes by recruiting DNMT1 to methylate some promoters and suppress TICs. These findings suggest that a combination of endocrine therapy and DAXX-stabilizing agents may inhibit ER⁺ tumor recurrence. SIGNIFICANCE: Estradiol-mediated stabilization of DAXX is necessary and sufficient to repress genes associated with stemness, suggesting that the combination of endocrine therapy and DAXX-stabilizing agents may inhibit tumor recurrence in ER⁺ breast cancer.

Inequity in rehabilitation interventions after hip fracture: a systematic review

OBJECTIVE

to determine the extent to which equity factors contributed to eligibility criteria of trials of rehabilitation interventions after hip fracture. We define equity factors as those that stratify healthcare opportunities and outcomes.

DESIGN

systematic search of MEDLINE, Embase, CINHAL, PEDro, Open Grey, BASE and ClinicalTrials.gov for randomised controlled trials of rehabilitation interventions after hip fracture published between 1 January 2008 and 30 May 2018. Trials not published in English, secondary prevention or new models of service delivery (e.g. orthogeriatric care pathway) were excluded. Duplicate screening for eligibility, risk of bias (Cochrane Risk of Bias Tool) and data extraction (Cochrane's PROGRESS-Plus framework).

RESULTS

twenty-three published, eight protocol, four registered ongoing randomised controlled trials (4,449 participants) were identified. A total of 69 equity factors contributed to eligibility criteria of the 35 trials. For more than 50% of trials, potential participants were excluded based on residency in a nursing home, cognitive impairment, mobility/functional impairment, minimum age and/or non-surgical candidacy. Where reported, this equated to the exclusion of 2,383 out of 8,736 (27.3%) potential participants based on equity factors. Residency in a nursing home and cognitive impairment were the main drivers of these exclusions.

CONCLUSION

the generalisability of trial results to the underlying population of frail older adults is limited. Yet, this is the evidence base underpinning current service design. Future trials should include participants with cognitive impairment and those admitted from nursing homes. For those excluded, an evidence-informed reasoning for the exclusion should be explicitly stated.

PROSPERO

CRD42018085930.

Abstract 5845: Roles for MLL2/ KMT2D or MLL3/ KMT2C in HER+ breast cancer stem cells

A major clinical challenge for the treatment of breast cancer (BC) is drug resistance. Cancer stem cells (CSCs) may contribute to drug resistance despite therapy. The HER2-positive subtype of BC contains a gene amplification for the ERBB2 proto-oncogene and these tumors are treated with anti-HER2 therapy. Anti-HER2 therapy, such as trastuzumab or lapatinib, increases Notch signaling and is required for HER2+ breast tumor resistance and tumor recurrence. Notch promotes survival of BC CSCs cells. MLL2/KMT2D (Lysine Methyltransferase 2D) and MLL3/KMT2C (Lysine Methyltransferase 2C) are histone methyltransferases that directly control gene enhancer activity through methylation of histone3 lysine4 within enhancer nucleosomes. These complexes collaborate with transcription factors, such as Notch, to drive gene expression by helping to shape the epigenetic landscape of a cell. Recently, it was shown that lapatinib or a PI3K inhibitor increases MLL2 activity and this increase in MLL2 contributes to resistance. Both MLL2 and MLL3 were found to be required for CSCs differentiation, while MLL2 was required for upregulation of c-Myc in HER2+ cells. Recent breast cancer xeno-engraftment studies found that clonal selection and expansion of primary and metastatic breast tumors was associated with amplification of MLL3 in 80% of breast cancer xenografts, suggesting that increased MLL3 expression may contribute to the survival of CSCs in breast tumors. High expression of MLL2 and/or MLL3 predict poor outcome for women with HER2+ breast cancer from cBio portal and Kaplan-Meier Plotter datasets. We measured the expression levels of MLL2 and MLL3 transcripts in both bulk HER2+ breast cancer cells that are trastuzumab sensitive, cells that have acquired resistance to trastuzumab, and cancer stem-enriched mammospheres. Results from PCR analysis showed that MLL2 and MLL3 transcripts were increased in mammospheres compared to bulk cells. Mammosphere forming efficiency of trastuzumab sensitive cells was decreased when MLL2 or MLL3 was knocked down using RNAi. Mammosphere forming efficiency of anti-HER2 therapy resistant (BT474 TR) cells was significantly decreased upon MLL3 knockdown, while HCC1954 mammospheres were inhibited by either MLL2 or MLL3 knockdown. We next measured transcript levels of Notch genes and other stem, mesenchymal, and luminal genes to determine whether MLL2 or MLL3 is necessary for the proper expression of cell fate genes. We found that Notch3 transcripts were decreased in both BT474 and HCC1954 cells upon MLL2 knockdown. SNAIL and Notch1 transcripts were also decreased, suggesting that MLL2 is required for the expression of genes involved in regulating cancer stem cell fates. These results suggest that MLL2/KMT2D and its paralog MLL3/KMT2C are increased in CSCs-derived from HER2+ breast cancer and may regulate CSC genes such Notch1 and Notch3 to promote resistance to anti-HER2 based therapy.

Citation Format: Andrei Zlobin, Debra Wyatt, Mary Varsanik, Andrew Dingwall, Clodia Osipo.. Roles for MLL2/ KMT2D or MLL3/ KMT2C in HER+ breast cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5845.

Inhibition of HER2 Increases JAGGED1-dependent Breast Cancer Stem Cells: Role for Membrane JAGGED1

Purpose: HER2-positive breast cancer is driven by cells possessing stem-like properties of self-renewal and differentiation, referred to as cancer stem cells (CSC). CSCs are implicated in radiotherapy, chemotherapy resistance, and tumor recurrence. NOTCH promotes breast CSC survival and self-renewal, and overexpression of NOTCH1 and the NOTCH ligand JAGGED1 predict poor outcome. Resistance to anti-HER2 therapy in HER2⁺ breast cancer requires NOTCH1, and that combination of trastuzumab and a gamma secretase inhibitor (GSI) prevents tumor relapse in xenograft models.Experimental Design: The current study investigates mechanisms by which HER2 tyrosine kinase activity regulates NOTCH-dependent CSC survival and tumor initiation.Results: Lapatinib-mediated HER2 inhibition shifts the population of HER2⁺ breast cancer cells from low membrane JAGGED1 expression to higher levels, independent of sensitivity to anti-HER2 treatment within the bulk cell population. This increase in membrane JAGGED1 is associated with higher NOTCH receptor expression, activation, and enrichment of CSCs in vitro and in vivo Importantly, lapatinib treatment results in growth arrest and cell death of JAGGED1 low-expressing cells while the JAGGED1 high-expressing cells continue to cycle. High membrane JAGGED1 protein expression predicts poor overall cumulative survival in women with HER2⁺ breast cancer.Conclusions: These results indicate that higher membrane JAGGED1 expression may be used to either predict response to anti-HER2 therapy or for detection of NOTCH-sensitive CSCs posttherapy. Sequential blockade of HER2 followed by JAGGED1 or NOTCH could be more effective than simultaneous blockade to prevent drug resistance and tumor progression. Clin Cancer Res; 24(18); 4566-78. ©2018 AACR.

Preclinical study of a Kv11.1 potassium channel activator as antineoplastic approach for breast cancer

Potassium ion (K⁺) channels have been recently found to play a critical role in cancer biology. Despite that pharmacologic manipulation of ion channels is recognized as an important therapeutic approach, very little is known about the effects of targeting of K⁺ channels in cancer. In this study, we demonstrate that use of the Kv11.1 K⁺ channel activator NS1643 inhibits tumor growth in an in vivo model of breast cancer.

Tumors exposed to NS1643 had reduced levels of proliferation markers, high expression levels of senescence markers, increased production of ROS and DNA damage compared to tumors of untreated mice. Importantly, mice treated with NS1643 did not exhibit significant cardiac dysfunction. In conclusion, pharmacological stimulation of Kv11.1 activity produced arrested TNBC-derived tumor growth by generating DNA damage and senescence without significant side effects. We propose that use of Kv11.1 channels activators could be considered as a possible pharmacological strategy against breast tumors.

Abstract 4769: Targeting HER2 enriches Jagged1 high cancer stem cells in breast cancer

The human epidermal growth factor receptor 2 (HER2) positive subtype of breast cancer is characterized by gene amplification and/or protein overexpression of HER2. It is driven by a subpopulation of cells possessing stem cell properties of self-renewal and differentiation, known as Cancer Stem cells (CSCs). CSCs are implicated in tumor growth as well as radiotherapy and chemotherapy associated resistance. Notch receptors promote breast CSCs survival and self-renewal, and overexpression of a Notch ligand Jagged1 mRNA predicts poor prognosis in women with breast cancer. Our lab has published that Jagged1 or Notch1 is a critical target in trastuzumab/lapatinib (LAP) resistant HER2+ breast cancer. The study aimed to determine whether anti-HER2 therapy selects for Jagged-1/Notch-dependent CSCs that are responsible for tumor initiation. Surface expression of Notch1 and Jagged1 upon HER2 blockade using LAP was measured in HER2+ breast cancer cell lines (MDA-MB-453 and HCC1954) using flow cytometry. LAP treatment increased the Jagged1-positive subpopulation compared to vehicle. Cells were sorted based on Jagged1 cell surface expression and assessed for CSC-like properties (i.e. mammosphere forming efficiency, Aldefluor activity, expression of CD44high /CD24low, Notch target transcripts expression, and limiting dilution tumor initiating potential in athymic, nude mice). In addition, immunohistochemistry was performed on 145 HER2+ breast tumor microarray to detect cytoplasmic, membrane, or nuclear Jagged1 protein expression. Kaplan-Meier analysis was performed to determine overall survival. The results showed that upon HER2 inhibition, Jagged1 cell surface expression increased and Notch1 cell surface expression was unchanged. The Jagged1high subpopulation of cells showed elevated levels of Aldehyde dehydrogenase activity, Notch target gene transcripts, and mammosphere formation efficiency compared to vehicle treated cells. The MRK-003 γ-secretase inhibitor (GSI) prevented mammosphere formation in the Jagged1high cells indicating that Notch activation drives Jagged1high CSC survival. Also, we confirmed that Jagged1 expression is required for the enrichment of CSCs using a Jagged1 siRNA. Combined knockdown of Notch1 and Notch3 receptors was necessary to reduce LAP-enriched mammospheres suggesting that targeting HER2 enriches for a Jagged1-Notch1+Notch3 driven CSC phenotype. Importantly, higher membrane expression of Jagged1 protein in 145 HER2+ breast tumor specimens correlated with significantly lower overall cumulative survival. These results reveal that HER2 blockade in breast cancer cells enriches for a Jagged1high subpopulation that has higher CSC potential and is resistant to HER2 inhibitors. The implications of this work are that dual blockade of Jagged-1/Notch1/Notch3 and HER2 could be more effective than either therapy alone to eliminate both HER2 and Jagged-1-dependent cancer cells.

Citation Format: Deep S. Shah, Debra Wyatt, Andrew Baker, Andrew Green, Aleksandra Filipovic, Lucio Miele, Clodia Osipo. Targeting HER2 enriches Jagged1 high cancer stem cells in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4769. doi:10.1158/1538-7445.AM2017-4769

Abstract LB-121: DAXX is a novel Notch-1 gene target and biomarker of GSI-sensitivity in ER+ breast cancer

Breast cancer is a heterogeneous disease that is best treated based on the expressed biomarker profile. Currently, the major clinical challenges are drug resistance and metastatic spread. Cancer stem cells (CSCs) are believed to be responsible for drug resistance and disease progression despite therapy. We previously identified novel biomarkers that could potentially be used with novel therapeutic strategies that target CSCs. We demonstrated in a presurgical window biomarker study of 20 breast cancer patients with ER-positive disease that signaling through Notch receptors mediates expression of 18 genes. Twenty women with ER-positive tumors were treated with 14 days of ET (tamoxifen or letrozole), with the addition of the oral GSI MK-0752 on day 15 (3 days on, 4 days off, 3 days on). Definitive surgery was on day 25. Analysis of biomarkers using microarray and RT-PCR during ET combined with MK-0752 GSI revealed statistically significant modulation of 18 genes: pro-apoptotic DAXX and NOXA; a tumor suppressor LFNG; Notch signaling such as NOTCH1, NOTCH4, HEYL, HES1, and HEY2; as well as proliferation-associated transcripts MIK67, CCND1, CCNA2; stem cell markers RUNX1 and ALDH1; and novel genes such as RICTOR, RPTOR, MMP7, ADAM19, and PgR (Albain et al. Proc SABCS 2014). The goal of the current study was to identify whether Notch1 directly regulated the 18 identified genes. We measured binding of Notch1 to CBF-1 (CSL/RPBJκ) binding sites of the 18 genes using a Chromatin Immunoprecipitation assay (ChIP) to determine whether Notch1 directly regulates the 18 genes. We scanned and designed primers 5 kb upstream and downstream of transcription start sites of the 18 genes and demonstrated that Notch1 was recruited to CBF-1 sites of 16 out of 18 genes. Different distribution of Notch1 binding was observed across all of the genes. Classical Notch targets, HEY1 and HES1 were among the most responsive genes and used as positive controls. Notch1 was found to be highly enriched on CBF-1 regulatory elements for the DAXX and NOXA genes. Binding of Notch1 to DAXX promoter elements increased in response to estrogen deprivation and this increase was attenuated upon GSI treatment. The biological activity of most genes was measured using the mammosphere-forming assay as a surrogate for CSC survival. Estrogen deprivation increased mammosphere-forming efficiency of ER+ breast cancer cells more than 2 fold compared to estrogen treatment. GSI blocked mammosphere formation by 95%-98% in response to anti-estrogen treatment. DAXX expression, was found to be necessary for GSI-mediated blockade of mammosphere formation. ChIP and mammosphere forming data calculated by ANOVA were found to be statistically significant. These results demonstrated that Notch1 is a direct transcriptional regulator of 16 genes identified by the clinical trial and in particular, DAXX, a pro-apoptotic gene that could serve as a cancer stem cell biomarker for anti-Notch therapy in ER+ breast cancer. Supported by a grant from the Breast Cancer Research Foundation.

Citation Format: Andrei Zlobin, Debra Wyatt, Jeffrey C. Bloodworth, Susan Hilsenbeck, Suzanne Fuqua, Lucio Miele, Kathy S. Albain, Clodia Osipo. DAXX is a novel Notch-1 gene target and biomarker of GSI-sensitivity in ER+ breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-121.

PKCα Attenuates Jagged-1-Mediated Notch Signaling in ErbB-2-Positive Breast Cancer to Reverse Trastuzumab Resistance

PURPOSE

Breast cancer is the second leading cause of cancer mortality among women worldwide. The major problem with current treatments is tumor resistance, recurrence, and disease progression. ErbB-2-positive breast tumors are aggressive and frequently become resistant to trastuzumab or lapatinib. We showed previously that Notch-1 is required for trastuzumab resistance in ErbB-2-positive breast cancer.

EXPERIMENTAL DESIGN

Here, we sought to elucidate mechanisms by which ErbB-2 attenuates Notch signaling and how this is reversed by trastuzumab or lapatinib.

RESULTS

The current study elucidates a novel Notch inhibitory mechanism by which PKCα downstream of ErbB-2 (i) restricts the availability of Jagged-1 at the cell surface to transactivate Notch, (ii) restricts the critical interaction between Jagged-1 and Mindbomb-1, an E3 ligase that is required for Jagged-1 ubiquitinylation and subsequent Notch activation, (iii) reverses trastuzumab resistance in vivo, and (iv) predicts better outcome in women with ErbB-2-positive breast cancer.

CONCLUSIONS

The clinical impact of these studies is PKCα is potentially a good prognostic marker for low Notch activity and increased trastuzumab sensitivity in ErbB-2-positive breast cancer. Moreover, women with ErbB-2-positive breast tumors expressing high Notch activation and low PKCα expression could be the best candidates for anti-Notch therapy.

Best practice guidelines on publishing ethics: a publisher's perspective, 2nd edition

Wiley has updated its publishing ethics guidelines, first published in 2006. The new guidelines provide guidance, resources and practical advice on ethical concerns that arise in academic publishing for editors, authors and researchers, among other audiences. New guidance is also included on whistle blowers, animal research, clinical research and clinical trial registration, addressing cultural differences, human rights and confidentiality. The guidelines are uniquely interdisciplinary, and were reviewed by 24 editors and experts chosen from the wide range of communities that Wiley serves. They are also published in Advanced Materials, Headache, Annals of the New York Academy of Sciences, Social Science Quarterly, and on the website http://exchanges.wiley.com/ethicsguidelines.

Abstract 1823: Novel regulation of Jagged1 by ErbB2 in breast cancer: implications for anti-ErbB2 therapy

We have demonstrated that Notch1 is required for trastuzumab resistance in ErbB2 positive breast cancer. This indicates that ErbB2 suppresses Notch1 in breast cancer and therapeutic intervention targeting ErbB2 might have an unintended consequence which is aberrant up regulation of Notch1 which is a breast oncogene.

However, the mechanism of action by which ErbB2 restricts Notch1 activation is unknown. In this current study, we investigated the role of cis- and trans-activation of Notch signaling by Notch ligands which are developmentally conversed to tightly regulate Notch activation. To address this hypothesis, we performed co-culture studies using fibroblasts expressing no Notch ligands or over-expressing human Jagged1 or Deltalike1 and ErbB2 positive breast cancer cells. We performed flow cytometry to isolate breast cancer cells after co-culture and extracted RNA to measure expression of Notch gene targets as a measure of Notch activity. The results showed that trastuzumab, Lapatinib, or ErbB2 knockdown increased overall Notch activition. Similarly, Co-culture with Jagged1-expressing fibroblasts increased overall Notch activation. However, Knocked down of Jagged1 in the breast cancer cells had little effect on ligand-induced Notch activation relieving the possibility of cis-inhibition. In contrast, Jagged1 knocked down abrogated trastuzumab-induced Notch activation in the breast cancer cells. These results suggest that ErbB2 might restrict Notch activation by preventing Jagged1-mediated trans activation of Notch and not by promoting cis-inhibition. Confocal immunofluorescence showed that Jagged1 is localized with Notch1 when ErbB2 is hyperactive but is trafficked to the cell surface in response to trastuzumab. K44ADynamin abrogated Jagged1 expression on the cell surface as measured by IF and surface biotinylation studies. Furthermore, K44ADynamin expression abrogated trastuzumab-induced Notch1 activation. Importantly, we measured growth consequences of Jagged1-mediated Notch activation in response to trastuzumab and found that Jagged1 is necessary for survival of ErbB2 positive breast cancer cells and trastuzumab resistance as measured by cell cycle analysis and Annexin V staining. These results taken together indicate that ErbB2 restricts Notch by limiting Jagged1-mediated trans-activation.

Citation Format: Clodia Osipo, Kinnari Pandya, Debra Wyatt. Novel regulation of Jagged1 by ErbB2 in breast cancer: implications for anti-ErbB2 therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1823. doi:10.1158/1538-7445.AM2014-1823

Estimating the number of viable animal cells in multi-well cultures based on their lactate dehydrogenase activities

A method is described for estimating the numbers ofanimal cells in multi-well culture by simultaneouslymeasuring the lactate dehydrogenase activity of thetotal culture and the medium. The difference betweenthe two reflects the dehydrogenase content of thecells and correlates with cell number. This LDH/INTmethod was tested using several lines of normal andtransformed suspension and adherent cells. Thelactate dehydrogenase activities of duplicate cultureswere determined colourimetrically using reactioncocktails containing lactate, NAD(+), diaphorase,and p-iodonitrotetrazolium violet, with and withoutTriton X-100. The difference in absorbance at 490 nm(DeltaA(490) = A(490, test) - A(490, control)) was used to calculate the lactatedehydrogenase activity of the total culture (+ Triton)and the medium (- Triton). The cellular lactatedehydrogenase activity (difference between totaland medium dehydrogenaseactivities) was proportional to viable cell number. The effects on cell growth of four metabolicinhibitors, sodium azide, actinomycin D,cycloheximide, and taxol, were determined using theLDH/INT assay and direct cell counting. The inhibitorconcentrations that caused decreases in the LDHactivity and cell number by 50% were similar. TheLDH/INT assay is quick and sensitive, works equallywell for adherent and suspension cells, and providesinformation about LDH activities of both the mediumand cells. It is particularly useful for screeningpotential cell-growth inhibitors.

Small ubiquitin-like modifier modification of arrestin-3 regulates receptor trafficking

Nonvisual arrestins are regulated by direct post-translational modifications, such as phosphorylation, ubiquitination, and nitrosylation. However, whether arrestins are regulated by other post-translational modifications remains unknown. Here we show that nonvisual arrestins are modified by small ubiquitin-like modifier 1 (SUMO-1) upon activation of β(2)-adrenergic receptor (β(2)AR). Lysine residues 295 and 400 in arrestin-3 fall within canonical SUMO consensus sites, and mutagenic analysis reveals that Lys-400 represents the main SUMOylation site. Depletion of the SUMO E2 modifying enzyme Ubc9 blocks arrestin-3 SUMOylation and attenuates β(2)AR internalization, suggesting that arrestin SUMOylation mediates G protein-coupled receptor endocytosis. Consistent with this, expression of a SUMO-deficient arrestin mutant failed to promote β(2)AR internalization as compared with wild-type arrestin-3. Our data reveal an unprecedented role for SUMOylation in mediating GPCR endocytosis and provide novel mechanistic insight into arrestin function and regulation.

Cross-talk between notch and the estrogen receptor in breast cancer suggests novel therapeutic approaches

High expression of Notch-1 and Jagged-1 mRNA correlates with poor prognosis in breast cancer. Elucidating the cross-talk between Notch and other major breast cancer pathways is necessary to determine which patients may benefit from Notch inhibitors, which agents should be combined with them, and which biomarkers indicate Notch activity in vivo. We explored expression of Notch receptors and ligands in clinical specimens, as well as activity, regulation, and effectors of Notch signaling using cell lines and xenografts. Ductal and lobular carcinomas commonly expressed Notch-1, Notch-4, and Jagged-1 at variable levels. However, in breast cancer cell lines, Notch-induced transcriptional activity did not correlate with Notch receptor levels and was highest in estrogen receptor alpha-negative (ERalpha(-)), Her2/Neu nonoverexpressing cells. In ERalpha(+) cells, estradiol inhibited Notch activity and Notch-1(IC) nuclear levels and affected Notch-1 cellular distribution. Tamoxifen and raloxifene blocked this effect, reactivating Notch. Notch-1 induced Notch-4. Notch-4 expression in clinical specimens correlated with proliferation (Ki67). In MDA-MB231 (ERalpha(-)) cells, Notch-1 knockdown or gamma-secretase inhibition decreased cyclins A and B1, causing G(2) arrest, p53-independent induction of NOXA, and death. In T47D:A18 (ERalpha(+)) cells, the same targets were affected, and Notch inhibition potentiated the effects of tamoxifen. In vivo, gamma-secretase inhibitor treatment arrested the growth of MDA-MB231 tumors and, in combination with tamoxifen, caused regression of T47D:A18 tumors. Our data indicate that combinations of antiestrogens and Notch inhibitors may be effective in ERalpha(+) breast cancers and that Notch signaling is a potential therapeutic target in ERalpha(-) breast cancers.

A review of a multiprofessional cancer course

The report of the Expert Advisory Group on Cancer (the Calman-Hine Report) (Department of Health 1995) set out a clear framework of services for people with cancer in England and Wales. Subsequent developments, such as The NHS Cancer Plan (Department of Health 2000a), have built on this framework. What emerges clearly from these documents is the importance of a skilled and knowledgeable workforce in delivering high-quality cancer services. Although appropriate educational courses exist for some professional groups, such as nurses, cancer care has traditionally received scant attention in curricula for the allied health professionals (AHPs), either before or after qualification. This article describes the development and successful implementation of a course in cancer care aimed specifically at AHPs. Using Skilbeck's (1984) curriculum model as a framework, the development and design of the course, and aspects of its delivery, are examined. Evaluation of the first 2 years of the course reveals that it is popular and perceived as interesting and relevant to AHPs involved with patients with cancer in general and specialist settings.

Nested multiplex polymerase chain reaction for the diagnosis of cutaneous herpes simplex and herpes zoster infections and a comparison with electronmicroscopy

Herpes simplex virus (HSV) and varicella zoster virus (VZV) are common causes of cutaneous and mucocutaneous vesicular eruptions. Laboratory diagnostic techniques include Tzanck smears, electronmicroscopy, antigen detection and viral culture. This paper describes a nested multiplex polymerase chain reaction with respective sensitivities of 0.0001, 0.01 and 0.1 TCID50 for VZV, HSV-1 and HSV-2. The assay was used in (a) a salvage capacity for slides already processed for electronmicroscopy, and (b) as a front-line assay for prospectively processed specimens. Sixty-two glass slides with vesicle lymph/scrapings from 58 patients with suspected cutaneous herpetic lesions were examined. The clinical presentations were described as atypical/not specified (24), VZV (20) or HSV (18), and involved eruptions from diverse anatomical sites, including the genitalia. Of the 62 specimens, 6 and 38 were positive by electronmicroscopy and multiplex PCR respectively, giving a comparative sensitivity of 16% for electronmicroscopy. Nested multiplex PCR identified 15 VZV and 20 HSV-1 infections. Where the clinical details indicated either HSV or VZV (38/62), nested multiplex PCR was statistically likely to be reactive (26/38 vs. 9/24) (chi2 P = 0.000004) whereas electronmicroscopy was not (4/38 vs. 2/24) (chi2 P= 0.77). Where the clinical details indicated VZV (20/62) or HSV (18/62), nested multiplex PCR was statistically more likely to confirm VZV (10/20 vs. 5/42) (chi2 P= 0.001) or HSV (9/18 vs. 11/44) (chi2 P = 0.05) respectively. Two suspected HSV and 6 suspected VZV infections were shown to be VZV and HSV respectively by nested multiplex PCR.

Description of a nonlethal herpes simplex virus type 1 glycoprotein D deletion mutant affecting a site frequently used for PCR

We report a herpes simplex virus type 1 mutant which failed to amplify with a commonly used glycoprotein D primer set. The virus contained a nine-base deletion in the gene's 5' nontranslated region. The altered amplicon was clearly distinguishable on a 4% high-resolution agarose gel.

Negotiation savvy: level the playing field by understanding sex differences

The ability to negotiate plays a key role in one's professional and personal life. Negotiations between nurses, managers, physicians, patients, and family members in the critical care environment can be difficult and stressful. If men and women want to negotiate successfully, they must know the steps of negotiation and the sex differences when approaching the negotiation process.

A comparison of virus isolation, indirect immunofluorescence and nested multiplex polymerase chain reaction for the diagnosis of primary and recurrent herpes simplex type 1 and type 2 infections

134 swabs in viral transport medium were received from 126 patients with suspected clinical HSV-1 and HSV-2 infections. They were tested by (i) nested multiplex polymerase chain reaction NMPCR (strongly positive specimens had visible bands on both rounds of PCR) without prior extraction, (ii) culture in primary rhesus monkey kidney, E6-Vero, RD and HEp-2 cells and (iii) antigen detection by immunofluorescence (IF). Antigen detection employed four novel pools (A-D) of monoclonal antibodies (Mab): A was HSV-1 specific, B was HSV-2 specific while C and D were generic. In comparison to NMPCR the sensitivity and specificity of (i) culture was 59% (22/37) and 100% (134/134), (ii) IF by Pool A was 59% (16/27) and 100% (117/117), (iii) IF by Pool B was 40% (4/10) and 100% (130/130) and (iv) IF by Pools C and D were 60% (18/30) and 100% (96/96). Specimens positive by culture were more likely to be strongly positive by NMPCR (chi2 P = 0.004). Typing by each method concurred on all occasions. NMPCR was cost effective, easier to perform and was the most sensitive method for HSV detection. It should become the method of choice for HSV diagnosis.

Melanocytic nevi in children treated with growth hormone

There is concern that growth hormone (GH) therapy may influence the growth of melanocytic nevi. In a review of the experience of the National Cooperative Growth Study, we found no excess of skin cancer in children who were treated with GH. We also reviewed our experience in 90 children with GH deficiency and 24 with Turner syndrome. We found no difference in the nevi count between control subjects and children with GH deficiency, even after many years of GH therapy. Nor was there any relation between the duration of therapy and the nevi count. Children with Turner syndrome had more nevi, but there was no relation to the duration of GH therapy. These findings and the absence of a greater frequency of skin cancer in acromegaly are reassuring. It is unlikely that GH therapy has a significant influence on nevi count or the risk of skin cancer.

Negotiation strategies for men and women

The ability to negotiate plays a key role in one's professional and personal life. If men and women want to negotiate successfully, they must know the steps of negotiation plus the sex differences when approaching the negotiation process.

Scholarly activities among clinical laboratory science faculty

OBJECTIVES

To describe the research and scholarly productivity of faculty in four-year college and university clinical laboratory science (CLS) programs. To identify meaningful scholarship, to assign values to that scholarship, and to list the top 15 CLS programs according to faculty research productivity.

DESIGN

In 1996, a national study involving 127 college and university CLS programs was conducted to determine whether faculty were participating in research. A questionnaire was distributed to 505 faculty members. Data from 286 respondents (57% response) representing 114 of 127 (90%) CLS programs were analyzed.

SETTING

The study took place at The Ohio State University with collaboration from the University of Tennessee-Memphis and the University of Minnesota.

PARTICIPANTS

All CLS faculty within a four-year university or college sponsoring a CLS program were invited to participate.

MAIN OUTCOME MEASURES

To determine whether CLS faculty scholarly activities have been strengthened in the last decade, to quantitate scholarship productivity by point assessment, and to list the top 15 CLS programs according to faculty research productivity.

RESULTS

Research productivity included time spent in research, numbers of publications and presentations, and grantsmanship. Data indicate that faculty who possess earned doctorates and are employed by research universities have higher levels of research productivity. While 46% of the CLS faculty hold doctorates and 50% are tenured, 42% of all CLS faculty members have not published a research paper or abstract since 1990. Conversely, faculty in some non-research institutions may not be expected to participate in such scholarly activities. On the other hand, 23% of the faculty responding had published six or more articles or abstracts since 1990, 46% were successful in obtaining external funding, and 15% of faculty members had been awarded grants larger than $100,000.

CONCLUSIONS

The top 10% of clinical laboratory science faculty researchers are performing approximately one-half of all scholarly activities. The top fifteen research programs in CLS are identified, and not surprisingly, are located in research universities. In the past decade, and generally speaking, CLS faculty have made progress in scholarship including highest degree obtained, publications, presentations, and grantsmanship.

Research productivity and activities of clinical laboratory science faculty: a follow-up study

A national study was conducted in 1996 to compare clinical laboratory science faculty demographics, scholarly activities, and perceptions of the research environment with corresponding data reported in 1988. Faculty have made progress in earning doctorates (46%), achieving higher ranks (49%), and getting tenured (50%). Relatively few faculty are conducting much of the research, with the greater majority serving as teachers. Research productivity, as evaluated via research publications and presentations, showed that in 1996, full professors and those with doctorates published the most articles and abstracts in refereed journals; they also made more presentations than junior faculty. Faculty in research universities were more productive than those in four-year colleges and universities. The faculty surveyed in 1985 and those surveyed in 1996 perceived their research skills and environments to be almost identical. In both 1985 and 1996, the importance of research for promotion and tenure decisions ranked highest as a characteristic of the environment. Financial resources and time available for research ranked lowest.

Use of PCR in resolving diagnostic difficulties potentially caused by genetic variation of hepatitis B virus

AIMS

To assess the relevance of genetic variants of hepatitis B virus (HBV) and to demonstrate the usefulness of the polymerase chain reaction (PCR) in cases of HBV diagnostic difficulty.

METHODS

Five serum samples from patients that presented diagnostic difficulty in routine laboratories were sent to a research laboratory for PCR, and if appropriate, S gene sequencing, in vitro expression, and antigenic analysis.

RESULTS

The demonstration of HBV in serum by PCR allowed a definitive diagnosis of current infection. One serum sample with poor reactivity in a diagnostic assay had a minor hepatitis B surface antigen (HBsAg) variant and another with very poor reactivity had multiple variants of HBsAg. Transient HBsAg reactivity was observed in a recently vaccinated patient. A hepatitis Be antigen (HBeAg) false positive reaction was noted in a patient from a well defined risk group for HBV. One patient who was strongly HBsAg/HBeAg positive, but anti-hepatitis B core antibody negative, was viraemic.

CONCLUSIONS

PCR may become the gold standard for the diagnosis of current HBV infection. HBV variants are responsible for a proportion of diagnostically difficult cases. Modification of commercial assays is necessary to increase the sensitivity of detection of such variants.

Magnitude estimation scaling of the loudness of a wide range of auditory stimuli

The study of the perception of loudness lends itself well to the psychophysical scaling technique of magnitude estimation. This study was designed to extend the range of auditory stimuli used to study the magnitude estimation scaling of loudness. The five stimuli chosen were a 1000-Hz pure tone, narrow band noise (700-1300 Hz band width), broad band noise (100-10,000 Hz band width), rock music, and babble speech, i.e., speech in which meaning is not discernible because several individuals are talking at once. Subjects were 30 normal young women (M = 19 yr.). During the auditory magnitude-estimation task for each of the five stimuli, a subject was instructed to assign numbers to stimulus presented in a randomly ordered series of nine sensation levels (10, 20, 30, 40, 50, 60, 70, 80, and 90 dB SL). Multivariate analysis of variance for repeated measures indicated there were no significant differences in the numerical responses of the subjects for the five stimuli. A possible explanation for these results is the presence of an underlying stabilizing factor (internal scaling mechanism) that allows adults to scale loudness consistently irrespective of the type of auditory stimulus.

The influence of regional deposition on the pharmacokinetics of pulmonary-delivered human growth hormone in rabbits

The pulmonary deposition and pharmacokinetics of human growth hormone (hGH), administered by aerosol and instillate, in formulations containing 99mTc-DTPA (for gamma scintigraphic imaging) have been studied in five male New Zealand White rabbits. Gamma scintigraphy indicated that the peripheral:central deposition tended to be greater for aerosol (1.54) than for instillate (0.8). Two gamma scintigraphic methods were used to quantify dose deposited by aerosol, which permitted bioavailabilities to be determined. The bioavailable fraction for aerosolized hGH (45%) was greater than for instilled hGH (16%). This was attributed to the differential effects of mucociliary clearance. Absorption rate limited pharmacokinetics prevailed for both hGH formulations with post-peak half-lives approximately 10-fold greater than the intravenous elimination half-life of 40 min. Apparent absorption rate constants resulting from instillation and aerosolization were equivalent (0.0012 min-1 and 0.0020 min-1 respectively), however lung-to-blood transfer rate constants for aerosol delivery (0.00071 min-1) were greater than for instillation (0.00018 min-1).

Effect of abrupt discontinuation of high glucose infusion rates during parenteral nutrition

We measured serum glucose and insulin levels in 15 children older than 2 years of age for 30 minutes after abrupt discontinuation of total parenteral nutrition. Initially high insulin levels rapidly became normal, and glucose levels were stable after 15 minutes. No patient had biochemical or symptomatic hypoglycemia. Glucose infusion rate, age, or use of steroid therapy had no apparent influence. Abrupt discontinuation of total parenteral nutrition is safe in most children older than 2 years of age.

A simple standardised protocol for the production of monoclonal antibodies against viral and bacterial antigens

A simple standardised protocol for making monoclonal antibodies against a range of human bacteria and viruses is described. The protocol was designed to reduce the number of steps to a minimum. A one step footpad immunisation was followed by the fusion schedule 10-15 days later. A vital step in the technique was the use of the immunised mouse's spleen to provide a feeder layer post fusion. This simplified the protocol and more importantly greatly accelerated the growth of the hybridomas produced. Immunisation, fusion and clonal expansion of specific antibody secreting hybridomas was complete within 5 weeks. The percentage of hybridomas secreting specific antibody ranged from 6% to 28%, the majority of which were of the IgG isotypes. The method was economical in the use of tissue culture medium and simple to perform.

The pharmacokinetics of pulmonary-delivered insulin: a comparison of intratracheal and aerosol administration to the rabbit

The pulmonary deposition and pharmacokinetics of insulin, administered via an endotracheal tube as an aerosol and instillate, in formulations containing either 113mIn-DTPA or 99mTc-DTPA (for gamma scintigraphic imaging) have been studied in four male New Zealand White rabbits. Using a randomized crossover design, the pharmacokinetics of intravenous insulin were also characterized. Recovery of immunoreactive insulin after nebulization was greater than 90%, indicating that the aerosolisation procedure did not cause appreciable insulin degradation. Gamma scintigraphy demonstrated that the penetration index (peripheral:central deposition) for the aerosolized formulation (1.52) was much greater than that for the instillate (0.32). Gamma scintigraphy also allowed exact quantification of the dose deposited after aerosol administration and thus permitted accurate determination of bioavailabilities. The bioavailable fraction for aerosolized insulin was 10-fold greater than for instilled insulin (57.2 vs 5.6%). Mucociliary clearance was likely to be greater for the instillate since it showed a preferential central deposition; this may account for the lower bioavailability. Insulin pharmacokinetics from both pulmonary formulations were absorption rate limited, resulting in postpeak half-lives which were approximately 20-fold greater than the intravenous elimination half-life (3 min). The apparent absorption rate constants resulting from instillation and aerosolisation were statistically equivalent (0.015 and 0.011 min-1, respectively). Mucociliary clearance of insulin would result in an overestimation of the true absorption rate constant; hence if mucociliary transport were greater for the instillate, then the true airways to blood transfer rate constant will be higher for the aerosolized formulation.

Improved speed and accuracy of calculations with a programmable calculator in pediatric emergency scenarios

Both mathematical and selection errors may occur when ordering drug or fluid therapy in a busy emergency department. In an attempt to improve the speed and accuracy of such calculations, we programmed a hand-held calculator to assist in drug and intravenous fluid therapy dosages and rates for three emergency situations: diabetic ketoacidosis, asthma, and asystole. Performance by 58 subjects at various levels of training was compared when using either the programmable calculator or standard materials and methods. When standard methods were used, an average of 30.6 minutes was needed to complete the three scenarios, with an accuracy of 73%; by contrast, use of programmable calculator resulted in a significant decline in time needed to calculate doses (an average of only 8.5 minutes), with an improved accuracy of 98%. The use of a programmable calculator can result in a significant improvement in both speed and accuracy of drug and fluid selection and dosage and rate calculations, regardless of the level of the subject's medical training.

Transient hypoglycemia with hyperinsulinemia in a newborn infant with Rubinstein-Taybi syndrome

A newborn boy with Rubinstein-Taybi syndrome who had profound neonatal hypoglycemia is presented. The infant was a discordant fraternal twin with intrauterine growth retardation. The hypoglycemia was due to transient hyperinsulinemia, a condition often seen in small-for-gestational-age infants. Neonatal hypoglycemia may be common in infants with Rubinstein-Taybi syndrome, especially if they also have intrauterine growth retardation.

Comparison of a hydrocolloid dressing and silver sulfadiazine cream in the outpatient management of second-degree burns

The purpose of this prospective randomized study was to evaluate the use of an occlusive hydrocolloid dressing (Duoderm hydroactive, Squibb) and silver sulfadiazine (Silvadene, Marion) cream in the outpatient management of second-degree burns. The inclusion criteria consisted of burns less than 15% total body surface area that were evaluated within 24 hours of injury and did not require hospital admission. Fifty patients were randomly assigned after having been screened through a list of seven exclusion criteria. On initial evaluation the burns were photographed and screened for causative agent, location, size, depth, tetanus status, and presence of associated burns and injuries. Patients were seen in followup at least biweekly and evaluated for wound bed healing, wound margin healing, pain, number of dressing changes between visits, and ease of dressing application and removal. On final evaluation the burns were photographed and inspected for appearance of the healed burn, repigmentation, wound contraction, approximate time for dressing change, patient compliance, limitation of activity, overall impression of the treatment, and number of days for complete healing. Results were compared using a two-tailed t-test with p less than 0.01. Both groups were statistically similar in age, sex, and size. Duoderm-treated burns had statistically significantly better wound healing, repigmentation, less pain, fewer dressing changes, less time for dressing changes, and less cost. Duoderm-treated patients had statistically significantly less limitation of activity, better patient compliance, greater patient comfort, better overall acceptance, and felt the treatment was more aesthetically pleasing. The results reveal that the Duoderm Hydroactive dressings are superior to Silvadene cream in the outpatient management of second-degree burns.