Perceptions of friendship, peers and influence on adolescent smoking according to tobacco control context: a systematic review and meta-ethnography of qualitative research

BACKGROUND

A relationship between smoking and interpersonal influences has been well established within the literature. There have been cultural shifts in denormalisation and a reduction in tobacco smoking in many countries. Hence there is a need to understand social influences on adolescents' smoking across smoking normalisation contexts.

METHODS

The search was conducted in July 2019 and updated in March 2022 within 11 databases and secondary sources. Search terms included schools, adolescents, smoking, peers, social norms and qualitative research. Screening was conducted by two researchers independently and in duplicate. Study quality was assessed using the eight-item Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-centre) tool for the appraisal of qualitative studies. Results were synthesised using a meta-narrative lens for meta-ethnography and compared across smoking normalisation contexts.

RESULTS

Forty one studies were included and five themes were developed, mapping onto the socio ecological model. The social processes by which adolescents take up smoking differed according to a mixture of school type, peer group structure and the smoking culture within the school, as well as the wider cultural context. Data available from smoking denormalised contexts, described changes in social interactions around smoking to cope with its stigmatisation. This was manifested through i) direct peer influence, whereby subtle techniques were employed, ii) group belonging whereby smoking was less likely to be seen as a key determinant of group membership and smoking was less commonly reported to be used as a social tool, and iii) popularity and identity construction, whereby smoking was perceived more negatively in a denormalised context, compared with a normalised context.

CONCLUSIONS

This meta-ethnography is the first study to demonstrate, drawing on international data, that peer processes in adolescent smoking may undergo changes as smoking norms within society change. Future research should focus on understanding differences across socioeconomic contexts, to inform the adaptation of interventions.

What matters to families about the healthcare of preterm or low birth weight infants

Introduction

Preterm and low birth weight (LBW) infants have complex long-term healthcare needs. The impact on families of caring for a sick infant is increasingly understood, with consequences for attachment and bonding and parental health and wellbeing immediately after birth and beyond. In this qualitative evidence synthesis, we aimed to understand what matters to families about the care provided to preterm or LBW infants in hospital and the community.

Methods

We searched nine databases and the reference lists of included studies for eligible studies using qualitative methods examining the views of families on healthcare for preterm or LBW infants. We used the Critical Appraisal Skills Programme checklist for qualitative studies to assess study quality and the GRADE-CERQual approach to assess confidence in each review finding. Studies were sampled after data saturation, and thematic synthesis techniques were used for analysis.

Results

203 studies were eligible for inclusion. We selected 49 studies from 25 countries for the analysis, based on methodological quality, data richness and on ensuring representation from settings with varying resources. Eight analytical themes were identified. Confidence in most results was moderate to high. What mattered to carers was a positive outcome for the child; active involvement in care; support to cope at home after discharge; emotional support for the family; the healthcare environment; their information needs were met; logistical support was available; and positive relationships with staff.

Conclusions

Enabling a positive post-natal period for families of small and sick infants is difficult. Experiences of care for preterm or LBW infants vary, but we found high consistency in what matters to families. This information can be used to shape global recommendations on support for infants and carers. More research is needed on what matters to parents who receive community-based care, especially in low resource settings.

Key messages

• We found high consistency across settings in what matters to families in the care of preterm infants.

• Understanding carers views and values ensures that care can be planned to meet the needs of infants and families.

Sublinear scaling of the cellular proteome with ploidy

Ploidy changes are frequent in nature and contribute to evolution, functional specialization and tumorigenesis. Analysis of model organisms of different ploidies revealed that increased ploidy leads to an increase in cell and nuclear volume, reduced proliferation, metabolic changes, lower fitness, and increased genomic instability, but the underlying mechanisms remain poorly understood. To investigate how gene expression changes with cellular ploidy, we analyzed isogenic series of budding yeasts from 1N to 4N. We show that mRNA and protein abundance scales allometrically with ploidy, with tetraploid cells showing only threefold increase in protein abundance compared to haploids. This ploidy-dependent sublinear scaling occurs via decreased rRNA and ribosomal protein abundance and reduced translation. We demonstrate that the activity of Tor1 is reduced with increasing ploidy, which leads to diminished rRNA gene repression via a Tor1-Sch9-Tup1 signaling pathway. mTORC1 and S6K activity are also reduced in human tetraploid cells and the concomitant increase of the Tup1 homolog Tle1 downregulates the rDNA transcription. Our results suggest that the mTORC1-Sch9/S6K-Tup1/TLE1 pathway ensures proteome remodeling in response to increased ploidy.

Exploring the association between school-based peer networks and smoking according to socioeconomic status and tobacco control context: a systematic review

BACKGROUND

Whilst prevalence of youth smoking in middle and high income countries has decreased, inequality has prevailed. The introduction of legislation regulating tobacco use in public spaces varies across countries, impacting the tobacco control context. Thus reviewing our knowledge of how social networks may influence smoking differently within different contexts is required to facilitate the development of context-specific interventions.

METHODS

The search, conducted on 31st May 2019, included the following smoking-related terms; schools, adolescents, peers and social networks. Inclusion and exclusion criteria were applied throughout the title and abstract screening and full text screening. Quality assessment and synthesis followed. Studies were narratively synthesised to identify changes according to legislative context. This synthesis was conducted separately for findings relating to three categories: socioeconomic status; social selection and influence; and network position.

RESULTS

Thirty studies were included. Differences in the relationship between network characteristics and smoking according to socioeconomic status were measured in five out of fifteen studies in Europe. Results varied across studies, with differences in network characteristics and their association with smoking varying both between schools of a differing and those of a similar socioeconomic composition. For studies conducted both before and after the introduction of comprehensive smoking legislation, the evidence for selection processes was more consistent than influence, which varied according to reciprocity. Findings showed that isolates were more likely to smoke and in-degree and out-degree centrality were related to smoking both before and after the introduction of legislation. The relationship between popularity and smoking was contingent on school level smoking prevalence in studies conducted before the introduction of legislation, but not after.

CONCLUSIONS

Overall, effects according to socioeconomic status were underreported in the included studies and no consistent evidence of change after the introduction of a comprehensive smoking ban was observed. Further network analyses are required using more recent data to obtain a comprehensive understanding of how network processes may influence smoking differently according to socioeconomic status, and how adaptation could be used to enhance intervention effectiveness.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42019137358 .

Site Readiness Framework to Improve Health System Preparedness for a Potential New Alzheimer’s Disease Treatment Paradigm

New therapies that address the underlying pathophysiology of Alzheimer’s Disease (AD), coupled with the growth of the AD population, will transform the AD care pathway and present significant challenges to health systems. We explored real-world challenges health systems may face in delivering potential new AD therapies with diverse stakeholders. Key challenges in care included integrating primary care providers into assessment and management, availability of memory care specialists, understanding payment and coverage issues and training mid-level providers to help coordinate care and serve as a shared resource across the system. This input informed a novel Site Readiness Framework for AD, comprising self-assessment exercises to identify health system capabilities and gaps and a framework of core strategies and responsive tools to help prepare to integrate new AD therapies. These resources may help health systems improve readiness to modify care pathways to integrate new therapies for AD.

OS12.7.A Characterization of intra-tumoral heterogeneity and differential immune activation during malignant progression of meningiomas on single cell level

BACKGROUND

As the most common intracranial tumor, meningiomas have caused increasing interest in the field of medical research. Based on their mutational profile, meningiomas can be separated into two main groups: NF2 altered meningiomas, which can occur at WHO grades 1 to 3, and non-NF2 mutant meningiomas with mutations in other genes, such as TRAF7, AKT1, KLF4, and SMO, which are usually of WHO grade 1. While this means that non-NF2 mutant meningiomas usually follow a benign course, risk stratification for NF2 mutant meningiomas remains difficult. As of now, the underlying mechanisms contributing to the malignant phenotype of some NF2 mutant meningiomas remained unknown, even though some molecular markers have been associated with an increased risk of recurrence. Here, we sought to characterize robust molecular subgroups for meningiomas and identify the critical steps in malignant progression of these tumors.

MATERIAL AND METHODS

We applied bulk RNA sequencing and proteomic analyses for 44 meningioma samples as well as single nuclei RNA sequencing analyses for an additional set of 26 meningiomas with a total of 46,002 nuclei. Both datasets comprised samples across the molecular landscape of meningiomas and WHO grades 1, 2, and 3.

RESULTS

The meningioma subgroups previously identified on epigenomic level were found consistently also on transcriptomic, proteomic, and phospho-proteomic levels. In addition, strong differences in numbers and types of infiltrating immune cells between subgroups became apparent. A decreased number of infiltrating macrophages and an activation to a more proinflammatory phenotype was observed for WHO grade 3 tumors. This observation correlated with lower expression levels of CSF1 in tumor cells of WHO grade 3 meningiomas, which was predicted to stimulate macrophages in WHO grade 1 and 2 tumors. Moreover, we identified several tumor cell subpopulations, each defined by a distinct phenotype, shared across samples. Their proportions in the tumor strongly depended on tumor grade. Especially a subpopulation characterized by an elevated stress response and TGFβ signaling activity was found specifically in WHO grade 3 cases.

CONCLUSION

Our findings establish molecular subgroups for meningiomas that are robust across multiple levels with characteristic differences in pathway activities and demonstrate a subtype-specific immune activation, both of which may be basis for novel treatment strategies.

Administration and monitoring of clofazimine for NTM infections in children with and without cystic fibrosis

Few studies have evaluated clofazimine (CLOF) drug monitoring and safety in children. We treated 10 children, 8 with CF, for NTM infection with multiple antimicrobials, including CLOF. All had serial blood CLOF concentrations measured and were followed for adverse events. Despite CLOF dose escalation, most children with CF did not reach a target CLOF concentration. Our data suggest that children with CF may require earlier initiation of CLOF at higher doses than is currently recommended.

Deep muscle-proteomic analysis of freeze-dried human muscle biopsies reveals fiber type-specific adaptations to exercise training

Skeletal muscle conveys several of the health-promoting effects of exercise; yet the underlying mechanisms are not fully elucidated. Studying skeletal muscle is challenging due to its different fiber types and the presence of non-muscle cells. This can be circumvented by isolation of single muscle fibers. Here, we develop a workflow enabling proteomics analysis of pools of isolated muscle fibers from freeze-dried human muscle biopsies. We identify more than 4000 proteins in slow- and fast-twitch muscle fibers. Exercise training alters expression of 237 and 172 proteins in slow- and fast-twitch muscle fibers, respectively. Interestingly, expression levels of secreted proteins and proteins involved in transcription, mitochondrial metabolism, Ca2+ signaling, and fat and glucose metabolism adapts to training in a fiber type-specific manner. Our data provide a resource to elucidate molecular mechanisms underlying muscle function and health, and our workflow allows fiber type-specific proteomic analyses of snap-frozen non-embedded human muscle biopsies.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Associations between school-based peer networks and smoking according to socioeconomic status and tobacco control context: protocol for a mixed method systematic review

BACKGROUND

Smoking remains a major public health concern. School-based social networks influence uptake of smoking among peers. During the past two decades, the UK macro-systemic context within which schools are nested and interact with has changed, with anti-smoking norms having become set at a more macro-systemic level. Whilst the overall prevalence of smoking in the UK has decreased, inequality has prevailed. It is plausible that the influence of school-based social networks on smoking uptake may vary according to socioeconomic status. Therefore, this study aims to understand how social influence on smoking among adolescents has changed in line with variance within and between contexts according to time and geography.

METHODS

The following databases will be searched: Medline, PsycINFO, Embase, Applied Social Sciences Index and Abstracts (ASSIA), British Education Index, Sociological abstracts, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Education Resources Information Center (ERIC) and Scopus. Additional searches will include reference checking of key papers, citation tracking, word of mouth and grey literature searches. The search strategies will incorporate terms relating to smoking, adolescents, schools, peers, network analysis and qualitative research. Titles and abstracts and full texts will be independently screened and assessed for quality by at least two researchers. Included studies will be assessed for quality, and data will be extracted for synthesis, including participant characteristics, setting and tobacco control context, study design and methods, analysis and results and conclusions. Quantitative findings will be narratively synthesised, whilst a lines of argument synthesis combined with refutational analysis will be employed to synthesise qualitative data. Both sets of findings will be charted on a timeline to add context to network findings and obtain an enhanced understanding of changes over time.

DISCUSSION

This protocol is for a mixed methods synthesis of both social network findings, to investigate social structures and qualitative studies, to elicit contextual information. The review will synthesise changes in the context of social influence on adolescent smoking over time and geographically. As context is increasingly recognised as a key source of complexity, this enhanced understanding will help to inform future interventions targeting smoking through social influence. This will help to enhance their relevance to context, subsequent effectiveness and targeting of inequalities.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019137358.

The overall metastatic rate in early esophageal adenocarcinoma: long-time follow-up of surgically treated patients

The overall metastatic potential of surgically treated early esophageal adenocarcinoma has not been studied in detail. This paper therefore assessed lymph node metastases at surgery, loco regional and distant metastases, in order to assess the metastatic potential of early esophageal adenocarcinoma. Two hundred and seventeen patients (53 T1a, 164 T1b; median follow-ups 87 and 75 months, 187 males) diagnosed with early esophageal adenocarcinoma and treated with esophagectomy in our tertiary center's database between July 2000 and December 2015 were included. All metastatic events were retrospectively analyzed, their topographic distribution was assessed, and the overall metastatic rate was calculated. Lymph node metastases occurred in 39 patients (18%) and 29 (13.4%) developed recurrences. Lymph node metastases were absent in m1 and m2 tumors and rare in m3 (1/18), m4 (5/21), and sm1 (4/42), but more frequent in sm2 (11/44) and sm3 tumors (18/78). Locoregional recurrences were exceedingly rare in m3 (2/18), m4 (1/21), sm1 (1/42), and sm2 (2/44), but frequent in sm3 (12/78). In contrast, distant metastases were more frequent with 2/18 in m3, 1/21 in m4, 4/42 in sm1, 4/44 in sm2, and 13/78 in sm3. Overall metastatic rates of 11.9% in sm1 (submucosal layer divided into equal thirds), 27.3% in sm2, and 32.1% in sm3 tumors were calculated. This first report of the metastatic potential of early esophageal adenocarcinoma provides a meticulous assessment of the overall metastatic risk. Metastatic events pose a relevant risk in surgically treated patients with esophageal adenocarcinoma with distant metastases being more frequent than locoregional recurrences.

Systematic review of publicity interventions to increase awareness amongst healthcare professionals and the public to promote earlier diagnosis of type 1 diabetes in children and young people

BACKGROUND

Children with new onset type 1 diabetes (T1D) are at risk of developing the life-threatening condition ketoacidosis if they have a delayed diagnosis. The rate of children presenting in ketoacidosis remains high in a number of countries worldwide. To ensure interventions to raise awareness of symptoms are effective a systematic review was conducted to evaluate previous publicity campaigns.

METHODS

A range of databases was searched using search terms relating to T1D, publicity campaigns, and symptom awareness. Identified articles were checked against the inclusion criteria, ensuring interventions were designed to target individuals prior to diagnosis of T1D. Papers were independently assessed under the criteria specified within the Critical Appraisal Skills Programme checklist.

RESULTS

The initial search retrieved 1537 papers and following screening 20 were identified for full consideration. Thirteen did not meet the inclusion criteria, leaving 7 to be assessed. Of these 7, 2 observational case-control studies reported a reduction in the rate of ketoacidosis following a publicity campaign using posters and providing glucose testing equipment to primary healthcare professionals. Four observational cohort studies, utilized posters, and media campaigns; 2 reported a reduction in the rate of ketoacidosis and 2 reported no difference following their interventions. A feasibility study, not designed to evaluate effectiveness, reported some anecdotal evidence of a more timely diagnosis.

CONCLUSION

Due to the methodological limitations of the studies identified, it is not possible to make a definitive conclusion on the effectiveness of the interventions reported.

Plasma Exchange (PE) and Lymphocytapheresis (LCA) in Multiple Sclerosis (MS)

In 96 patients suffering from multiple sclerosis (MS) 277 plasma exchanges (PE) including 176 lymphocytaphereses were performed. Improvement was mainly seen in patients with a short course of disease and at acute exacerbations. Patients with chronic progressive and relapsing intermittent courses responded only poorly. One or two PE were sufficient to induce improvement which was only marginally altered by subsequent PE.

Our data confirm that only selected patients will benefit from PE-treatment especially those with acute exacerbations.

Abstract P5-06-09: Cyclin d1 binding to chromatin and the induction of chromosomal instability requires the fuzzy domain

The cyclin D1 gene encodes the regulatory subunit of a holoenzyme that phosphorylates and inactivates the retinoblastoma (Rb) and the nuclear respiratory factor 1 (NRF1) proteins to regulate nuclear DNA synthesis and mitochondrial biogenesis. Cyclin D1 is required for oncogene-dependent growth and genetic ablation of the murine cyclin D1 gene resulted in resistance to Ras or ErbB2-induced mammary tumorigenesis and APC-induced gastrointestinal tumorigenesis. Cyclin D1 overexpression occurs in human breast, prostate, lung, and gastrointestinal malignancies and its abundance is induced at the level of transcription, translation and through post-translational modifications. Cyclin D1 plays a key role in transcriptional regulation inducing gene expression governing chromosomal instability (CIN) and cell-cycle progression. Cyclin D1 is also known to bind TF regulatory regions in chromatin immuno-precipitation (ChIP) assays. Genome wide analysis of cyclin D1 occupancy using ChIP-Seq identified binding sites including both the coding and non-coding genome with enrichment for genes regulating CIN and the G2/M phase (Top2A, AurkB, Cenpp, Mlf1ip, Zw10, Ckap2) consistent with enrichment of cyclin D1 at G2/M and the finding that cyclin D1 induces CIN. We sought to identify the molecular mechanisms governing the recruitment of cyclin D1 in the context of local chromatin to promote CIN. In order to define the domain of cyclin D1 involved in aneuploidy and tumorigenesis, we transduced and assessed the induction of aneuploidy in MEF cells using cyclin D1 wt (wt), cyclin D1 C-terminus domain (C4), cyclin D1 mutant lacking of the E-box motif (ΔE) or ctrl. We also searched for potential histone protein interaction motifs in cyclin D1 and determined the epigenetic motif recognized by cyclin D1 using a histone peptide array. The recognition of an epigenetic code by cyclin D1 may facilitate genome wide expression changes during cell-cycle progression and tumorigenesis. We finally identified a “fuzzy” domain of cyclin D1 which is required to local chromatin access for regulatory promoter regions governing and promoting CIN.

Citation Format: Pestell RG, Di Sante G, Di Rocco A, Pupo C, Crosariol M, Tompa P, Tantos A, Wang C, Yu Z, Vadlamudi R, Mann M, Casimiro MC. Cyclin d1 binding to chromatin and the induction of chromosomal instability requires the fuzzy domain [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-06-09.

Mitochondrial specialization revealed by single muscle fiber proteomics: focus on the Krebs cycle

We have developed a highly sensitive mass spectrometry-based proteomic workflow to examine the proteome of single muscle fibers. This study revealed significant differences in the mitochondrial proteome of the four major fiber types present in mouse skeletal muscle. Here, we focus on Krebs cycle enzymes and in particular on the differential distribution of the two mitochondrial isocitrate dehydrogenases, IDH2 and IDH3. Type 1/slow fibers contain high levels of IDH2 and relatively low levels of IDH3, whereas fast 2X and 2B fibers show an opposite expression pattern. The findings suggest that in skeletal muscle, IDH2 functions in the forward direction of the Krebs cycle and that substrate flux along the cycle occurs predominantly via IDH2 in type 1 fibers and via IDH3 in 2X and 2B fibers. IDH2-mediated conversion of isocitrate to α-ketoglutarate leads to the generation of NADPH, which is critical to buffering the H2O2 produced by the respiratory chain. Nicotinamide nucleotide transhydrogenase (NNT), the other major mitochondrial enzyme involved in NADPH generation, is also more abundant in type 1 fibers. We suggest that the continuously active type 1 fibers are endowed with a more efficient H2O2 scavenging capacity to cope with the higher levels of reactive oxygen species production.

Integrative proteomic profiling of ovarian cancer cell lines reveals precursor cell associated proteins and functional status

A cell line representative of human high-grade serous ovarian cancer (HGSOC) should not only resemble its tumour of origin at the molecular level, but also demonstrate functional utility in pre-clinical investigations. Here, we report the integrated proteomic analysis of 26 ovarian cancer cell lines, HGSOC tumours, immortalized ovarian surface epithelial cells and fallopian tube epithelial cells via a single-run mass spectrometric workflow. The in-depth quantification of >10,000 proteins results in three distinct cell line categories: epithelial (group I), clear cell (group II) and mesenchymal (group III). We identify a 67-protein cell line signature, which separates our entire proteomic data set, as well as a confirmatory publicly available CPTAC/TCGA tumour proteome data set, into a predominantly epithelial and mesenchymal HGSOC tumour cluster. This proteomics-based epithelial/mesenchymal stratification of cell lines and human tumours indicates a possible origin of HGSOC either from the fallopian tube or from the ovarian surface epithelium.

High-grade serous ovarian cancer is the most common and aggressive ovarian cancer, with uncertain cell of origin. Here, the authors undertake a mass spectrometric analysis of 26 cancer cell lines and identify a protein signature that classifies ovarian cancer tissues into epithelial and mesenchymal groups.

A clinically weighted approach to outcome assessment in radial polydactyly

Currently available outcome assessment systems for radial polydactyly are mainly based on expert opinion. The aim of this study was to develop an outcome assessment system based on clinical data. We performed linear regression analysis on data from a multicentre study of 121 patients with radial polydactyly types II, IV and VII to develop a clinically weighted outcome assessment system. Items were weighted according to their influence on overall functional and aesthetic outcome in the regression analysis. Active flexion, scar appearance and prominence at amputation site were the main items influencing overall functional and aesthetic outcome (β = 0.393, β = 0.326 and β = 0.288, respectively). Palmar abduction, metacarpophalangeal joint deviation and nail appearance influenced overall functional and aesthetic outcome the least (β = -0.002, β = -0.104 and β = 0.070, respectively). Our proposed assessment system for radial polydactyly reflects the way clinicians value individual aspects of outcome as determinants of overall outcome and helps guide future treatment and evaluation of outcome.

LEVEL OF EVIDENCE

III.

Transverse soft tissue distraction preceding separation of complex syndactylies

Various surgical techniques are described for separation of syndactylies leading to good results. However, the use of standard techniques is limited in complex syndactylies with extensive bony fusion and tight soft tissues. The aim of this study was to assess the outcomes of a two-stage procedure involving progressive soft tissue distraction prior to syndactyly release. Between 1996 and 2012 we treated 168 complex syndactylies with this technique. The main indications were syndactylies in Apert syndrome. The digits were distracted through an external fixator at 0.5 mm/day. Distraction of 15-25 mm was achieved. Soft tissue distraction provided additional skin, a wider nail matrix and more bone in the form of callus. Thus subsequent modelling of the fingertips was improved, especially if they were closely fused. This technique facilitates treatment of complex cases and improves aesthetic outcome.

LEVEL OF EVIDENCE

Therapeutic IV.

[Differential Diagnoses of Trigger Thumb]

Trigger thumb is one of the most common hand pathologies in toddlers. Its differential diagnoses are thumb-in-palm deformity, hyperflexible thumb, thumb hypoplasia, and congenital stiffness of the distal interphalangeal joint of the thumb. This article describes typical clinical signs of these different diseases in order to enable surgeons to make the correct diagnosis leading to the right treatment.

[Epiphyseal Bar Resection for Correction of Clinodactyly]

BACKGROUND

Clinodactyly is a digital angulation in the radio-ulnar plane. Mostly it is seen on the little finger. The middle phalanx typically has a triangular or trapezoid shape (delta phalanx), resulting in radial deviation of the distal phalanx. Resection of the longitudinal epiphyseal bracket (physiolysis) with fat graft interposition is a possible surgical technique, which uses children's growth potential to correct the axial deviation.

AIM

The purpose of our study was to review the degree of correction at least 2 years postoperatively and after an average of 5 years postoperatively, and to find out if children´s age influences the results.

PATIENTS AND METHODS

23 children (43 little fingers) underwent physiolysis and were retrospectively analyzed after a median follow-up of 5 years (2.1-7.9 years). The active range of motion of the little finger's MP, PIP and DIP joints and finger-palm-distance were measured. Lateral deviation was determined by using standardized radiographs and subsequently compared with preoperative values. Patients were divided into 2 subgroups: younger than 3 years (16 fingers, group A), older than 3 years (27 fingers, group B). The achieved correction of the lateral deviation was compared between both groups.

RESULTS

All patients showed full active range of motion in all joints of treated fingers. Finger-palm-distance was 0 cm. No complications occurred. The mean preoperative deviation of all patients was 37°±11, which improved after surgery by 17°±11 (i. e. 44.0%±23.1 of initial findings). Group A demonstrated a mean preoperative lateral deviation of 40°±9, and group B a mean deviation of 36°±12. In both groups we saw a similar improvement (group A mean: 17°±10, group B mean: 17°±11). In group A there was a wider dispersion of postoperative results. In the age group 7 to 10, the results of individual cases show the large variability of the corrective potential. X-rays revealed the following incidental findings after surgery: a premature fusion of the proximal radial epiphyseal plates in 2 fingers and a sinuous-shaped proximal radial epiphyseal plate in 12 other fingers.

CONCLUSION

Resection of the longitudinal epiphyseal bracket with fat graft interposition is a technically simple and effective treatment option for clinodactyly, particularly in children of 3 to 6 years of age.

[Distraction Osteogenesis is an Effective Method to Lengthen Digits in Congenital Malformations]

PURPOSE

The aim of this study was to investigate the feasible amount of lengthening by distraction osteogenesis in congenital hand deficiencies.

PATIENTS AND METHODS

A total of 60 patients (1.6-17.8 years) underwent lengthening of 71 bones between 1994 and 2014. Bone lengthening was performed on 46 metacarpals and 25 phalanges. Mostly the first (n=30) and the fifth (n=21) rays were lengthened. Bone lengthening was performed to treat primarily symbrachydactyly (b=32) and amniotic band syndrome (n=10). To analyze the amount of lengthening preoperative radiographs and radiographs taken while removing the external fixator were compared. The charts were reviewed regarding age at surgery, duration of lengthening, duration of bony consolidation, complication, etc.

RESULTS

The average of metacarpal distraction was 18.4 mm=73% lengthening with respect to the preoperative length; the average of phalange distraction was 14.0 mm=77% of the preoperative length. In both, metacarpals and phalanges, a lengthening of > 100% of the preoperative bone length was possible. In target length was reached in 89% of the procedures. The average time for consolidation was 6.1 (1-20) days/mm lengthening. The external fixator was in use on average for 140 (50-346) days. After removing of the external fixator an axial K-wire was used to stabilize the callus in 9 procedure, and an iliac bone craft plus axial K-wire in 11 procedures. The rate of complications was 30% (early consolidation, deviation, joint dislocation, pin infection, tendon dislocation). All complications could be treated without with acceptable results.

CONCLUSION

Metacarpal and phalangeal distraction lengthening is an effective but demanding technique for ray reconstruction in congenital malformations of the hand. It is possible to lengthen a bone by more than 100%. Complications are common, but in most cases easy to handle.

Abstract S3-04: ESR1 coregulator binding inhibitor (ECBI) as a novel therapeutic to target hormone therapy resistant metastatic breast cancer

BACKGROUND: Estrogen contribute to the progression of breast cancer via estrogen receptor 1 (ESR1) and current therapies involve either antiestrogens or aromatase inhibitors. However, most patients develop resistance to these drugs. Critically, therapy-resistant tumors retain ESR1-signaling. Mechanisms of therapy resistance involve the activation of ESR1 in the absence of ligand or mutations in ESR1 that allow interaction between the ESR1 and coregulators leading to sustained ESR1 signaling and proliferation. For patients with therapy-resistant breast cancers, there is a critical unmet need for novel agents to disrupt ESR1 signaling by blocking ESR1 interactions with its coregulators.

METHODS: Using rational design, we synthesized and evaluated a small organic molecule (ESR1 coregulator binding inhibitor, ECBI) that mimics the ESR1 coregulator nuclear receptor box motif. Using in vitro cell proliferation and apoptosis assays, we tested the effect of ECBI on several breast cancer and therapy-resistant model cells. Mechanistic studies were conducted using established biochemical assays, reporter gene assays, RT-qPCR and RNA-Seq analysis. Differentially expressed genes were analyzed using Ingenuity Pathway Analysis (IPA). ESR1 positive (MCF7 and ZR75) xenografts were used for preclinical evaluation and toxicity. The efficacy of ECBI was tested using ex vivo cultures of freshly extirpated primary human breast tissues.

RESULTS: In estrogen induced proliferation assays using several ESR1 positive model cells, ECBI significantly inhibited growth and promoted apoptosis. Importantly, ECBI showed little or no activity on ESR1 negative cells. Further, ECBI also reduced the proliferation of several ESR1 positive hormonal therapy resistant cells. Mechanistic studies showed that ECBI interacts with ESR1, efficiently blocks ESR1 interactions with coregulators and reduces the ESR1 driven ERE reporter gene activity. Further, ECBI directly interacted with mutant-ESR1 with high affinity and significantly inhibited mutant-ESR1 driven oncogenic activity. RNA sequencing analysis revealed that ECBI blocks multiple ESR1 driven pathways, likely representing the ability of a single ECBI compound to block multiple ESR1-coregulator interactions. Treatment of ESR1-positive xenograft tumors with ECBI (10 mg/kg/day/oral) significantly reduced the tumor volume compared to control. Further, ECBI also significantly reduced the tumor growth of coregulator-overexpressed breast cancer cells in xenograft model. Using human primary breast tissue ex vivo cultures, we have provided evidence that ECBI has potential to dramatically reduce proliferation of human breast tumors.

CONCLUSIONS: The ECBI is a novel agent that targets ESR1 with a unique mechanism of action. ECBI has distinct pharmacologic advantages of oral bioavailability, in vivo stability, and is associated with minimal systemic side effects. Remarkably, ECBI block both native and mutant forms of ESR1 and have activity against therapy resistant breast cancer cell proliferation both in vitro and in vivo and against primary human tumor tissues ex vivo. Thus development of ECBI represents a quantum leap in therapies to target ESR1.

Citation Format: Vadlamudi RK, Sareddy GR, Viswanadhapalli S, Lee T-K, Ma S-H, Lee WR, Mann M, Krishnan SR, Gonugunta V, Strand DW, Tekmal RR, Ahn J-M, Raj GV. ESR1 coregulator binding inhibitor (ECBI) as a novel therapeutic to target hormone therapy resistant metastatic breast cancer. [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 S3-04.

Abstract P1-06-09: Proto-oncogene PELP1 signaling regulates breast cancer stem cells via G9a/EHMT2

BACKGROUND: Evolving evidence suggests that cancer stem cells (CSCs) evade hormonal therapy and therapy resistance occurs due to regrowth of tumor cells from cancer stem cells that escaped hormonal therapy or remained in the body after tumor resection. Recent studies suggest that estrogen stimulates breast cancer stem-cells and G9a/EHMT2 plays a critical role in stem cell maintenance. Proline, glutamic acid, and leucine rich protein (PELP1) is a proto-oncogene that functions as a critical coregulator of several nuclear receptors and other transcription factors. PELP1 is commonly overexpressed in hormone-related cancers, and is prognostically linked to shorter breast cancer survival. Recent studies from our lab discovered PELP1 interacts with G9a/EHMT2. However, it remains unknown whether PELP1-G9a signaling plays a role in breast cancer stem cell proliferation. The objective of this study is to develop small molecular inhibitors that block G9a/EHMT2 interactions and to test their utility.

METHODS: We isolated CD44high/CD24low CSCs from three breast cancer cell lines (ZR75, MCF7, T47D) using FACS. To test the effect of PELP1 inhibitors on CSCs, we cultured CSCs in SFM in the presence or absence of PELP1 inhibitors for a period of 7-10 days. Cells were analyzed for spheroid formation, morphological changes, immunofluorescence for differentiation markers, protein (Western) and RNA (RT-qPCR) analysis. Expression of differentiation markers K19 and K14 and stem cell markers CD133, CD44, Id1, Nestin, Musashi-1, SOX2, Notch2, and OCT1 was determined.

RESULTS: Using mapping studies, we identified a small peptide inhibitor (PIP1) that interferes PELP1 interaction with G9/EHMT2. Utilizing Hit-Ligand interaction site with the PELP1 hot spot residues based on 3D alignment and shape, we have identified 61 potential hits from Ligand-Based screening using a 10,000 Diverse Set. Screening of these 61 potential hits using MTT based cell viability assays identified three small organic molecule inhibitors (peptidomimetics) as leads. All three peptidomimetics (#20, #29, #34) showed activity similar to PELP1 peptide inhibitor 1 (PIP1) in assays using three different breast cancer cell lines. Further, PELP1 targeting peptidomimetic disrupted PELP1 interaction with G9a/EHMT2. Peptidomimetic treatment inhibited the proliferation of tamoxifen therapy resistant cells. In mechanistic studies, we found that knockdown of PELP1 inhibited stem cell maintenance. In FACS analysis of ZR75, ZR75-PELP1 and ZR75-PELP1KD cells, the percentage of CD44high/CD24low cells correlated with PELP1 status. Accordingly, in mammosphere formation assays, PELP1 targeting peptidomimetic significantly inhibited the formation of mammospheres and the size of the mammospheres was also substantially decreased. Further, in self-renewal assays, peptidomimetic-treated cells had decreased self-renewal capacity.

CONCLUSIONS: Collectively, our studies have discovered an essential role for PELP1 in breast cancer stem cell maintenance and identified the PELP1- G9a/EHMT2 axis as a potential therapeutic target for reducing stemness. Further, the novel small molecule inhibitors of PELP1 could be used for therapeutic targeting of breast cancer stem cells and therapy resistance.

Citation Format: Viswanadhapalli S, Mann M, Sareddy GR, Xaionan L, Vankayalapati H, Brann D, Vadlamudi RK. Proto-oncogene PELP1 signaling regulates breast cancer stem cells via G9a/EHMT2. [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 P1-06-09.