Abstract P3-04-26: Establishment and characterization of ST941/C; an ESR1-mutant ER+ breast cancer cell line and xenograft from a patient with acquired resistance to endocrine therapy

Background: The estrogen receptor (ERα) plays an integral role in the progression of luminal type breast cancers and while targeted endocrine therapies provide effective initial treatment many patients develop acquired resistance to treatment even with continued ER receptor expression. Recently studies identified ER mutations as a possible mechanism for acquired resistance and several activating point mutations have been identified including Y537S (ESR1Y537S) resulting in hormone independent proliferation in preclinical studies. However, lack of validated ESR1-mutant cell lines has limited detailed mechanistic studies of these mutations in endocrine-resistant ER+ breast cancer. Previously we established and evaluated a patient derived xenograft (PDX) designated ST941 representing ESR1Y537S-mutated ER+ breast cancer (Wick et al, SABCS 2015). To better understand the role of ESR1-mutations in endocrine resistant breast cancer we established an immortalized cell line from ST941 designated ST941/C to use for in vitro mechanistic assays and correlative in vivo studies.

Methods: The ST941/C cell line was generated from harvested low-passage ST941 PDX tissue using published methods. Once established the line was characterized by immunohistochemistry and NGS and its tumorigenicity assessed. Drug sensitivity studies were carried out evaluating relevant endocrine and chemotherapy agents and results compared with in vivo drug studies. Timepoints for cell proliferation assays were Days 4, 7 and 10 following cell plating using standard MTS assay. Endpoints for in vivo studies were a mean group tumor volume of ~1 cm3 or sixty days following treatment initiation.

Results: Subcutaneous cell injection into athymic nude mice produced xenografts which grew in the absence of exogenous hormone. The ST941/C cell line and resulting xenograft retained immunohistologic and NGS characteristics of the parent model including receptor expression and ER mutation. Both the cell line and xenograft were insensitive to most endocrine therapies including tamoxifen, fulvestrant and aromatase inhibitors and reported correlative activity towards docetaxel and other chemotherapies.

Conclusion: We have established and evaluated an ESR1-mutant cell line designated ST941/C which is tumorigenic in nude mice and potentially useful for mechanistic and correlative in vivo studies to better understand acquired resistance in endocrine-treated ER+ breast cancer.

Citation Format: Wick MJ, Diaz A, Thomas M, Moriarty A, Quinn M, Guerra M, Zhu P, Smith P, Tolcher AW, Puyang X, Patnaik A, Korpal M, Rasco D, Papadopoulos KP. Establishment and characterization of ST941/C; an ESR1-mutant ER+ breast cancer cell line and xenograft from a patient with acquired resistance to endocrine therapy [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 P3-04-26.

Effectiveness, safety, durability and immune recovery in a retrospective, multicentre, observational cohort of ART-experienced, HIV-1-infected patients receiving maraviroc

The aim of this retrospective, multicentre, observational study was to assess the durability, safety, immune recovery and effectiveness on viral suppression of antiretroviral therapy (ART) in a maraviroc (MVC)-based cohort. We collected clinical, demographical, immunological and virological parameters of adult HIV patients who were infected by CCR5-tropic virus and started an ART regimen containing MVC from 2005 to 2012. We created a longitudinal mixed model to assess the change over time of data. We enrolled 126 drug-experienced patients; the median duration of MVC treatment was 25 months. The probability of stopping ART at one year was 13.3%, and at three years was 27.3%. Statistically significant changes were observed for CD4+ cell count increase ( p < 0.001), HIV-RNA decrease ( p < 0.001) and total cholesterol decrease ( p = 0.005). Ninety-four patients (79.7%) had CD4 ≥ 200 cells/mm³ at baseline while nine of them reached this threshold at nine months (7.6%), 17 (13%) after nine months and six (5%) remained below 200 cells/mm³ at the end of the study. Overall, 114 patients (90.5%) achieved an HIV-RNA ≤ 50 cp/ml. A majority of patients maintained CD4 cell counts of ≥ 200 cells/mm³ and achieved an undetectable HIV viral load within three months. MVC-containing regimens are safe and appear to be a feasible therapeutic option for ART.

Formal caregivers’ perceptions of working in a home-based care for elderly

Introduction

Population aging is an issue increasingly gaining more prominence, as evidenced by the number of inquiries regarding the “problems” that this entails for society. This leads to a need to understand the role of caregiver for the elderly as the central figure of support in old age.

Aim

The purpose of this study was to describe formal caregivers’ perceptions of working conditions, difficulties and factors associated with quality of care in a Portuguese home-based care for elderly.

Methods

The participants were 8 formal caregivers whose profession falls under the categories of Direct Action Helper and Auxiliary Workers. The data were collected through individual face-to-face interviews and analysed using a content analysis following Bardin's method.

Results

The results show that the sample is female, aged from 32 to 53 years, with a professional exercise time between 8 and 16 years. Regarding the main conclusions of our research, we can say that our group of participants has a strong sense of team work which contributes to avoid situations of physical and emotional exhaustion; mostly caregivers can separate their personal and professional lives; there are some difficulties in communication between the caregivers and the elderly, however the most difficult situations are usually overcome due to the caregiver's understanding of the characteristics of institutionalized elderly; the matter of death is frequently seen as the most difficult situation to face.

Conclusions

The caregivers should have an awareness of the importance of kindness and respect, supporting positive thoughts and help the older people to retain control over their lives.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

A comparative cross-cultural study of the prevalence of late life depression in low and middle income countries

BACKGROUND

Current estimates of the prevalence of depression in later life mostly arise from studies carried out in Europe, North America and Asia. In this study we aimed to measure the prevalence of depression using a standardised method in a number of low and middle income countries (LMIC).

METHODS

A one-phase cross-sectional survey involving over 17,000 participants aged 65 years and over living in urban and rural catchment areas in 13 sites from 9 countries (Cuba, Dominican Republic, Puerto Rico, Mexico, Venezuela, Peru, China, India and Nigeria). Depression was assessed and compared using ICD-10 and EURO-D criteria.

RESULTS

Depression prevalence varied across sites according to diagnostic criteria. The lowest prevalence was observed for ICD-10 depressive episode (0.3 to 13.8%). When using the EURO-D depression scale, the prevalence was higher and ranged from 1.0% to 38.6%. The crude prevalence was particularly high in the Dominican Republic and in rural India. ICD-10 depression was also associated with increased age and being female.

LIMITATIONS

Generalisability of findings outside of catchment areas is difficult to assess.

CONCLUSIONS

Late life depression is burdensome, and common in LMIC. However its prevalence varies from culture to culture; its diagnosis poses a significant challenge and requires proper recognition of its expression.

Surgical treatment of bronchiectasis: A review of 20 years of experience

BACKGROUND

Bronchiectasis is defined as an abnormal and irreversible dilation and distortion of the bronchi, which has numerous causes. Surgical treatment of this disease is usually reserved for focal disease and when the medical treatment is no longer effective. We report our center experience and outcomes in bronchiectasis surgery during the last 20 years.

METHODS

Between 1994 and 2014, sixty-nine patients underwent surgical resection for bronchiectasis. Patient demographics, presenting symptoms, indications for surgical treatment, type of lung resection, morbidity and mortality, as well as clinical follow-up and outcomes were analyzed.

RESULTS

From the 69 patients included, 31 (44.9%) were male and 38 (55.1%) were female. Surgery was indicated because of unsuccessful medical therapy in 33 patients (47.8%), haemoptysis in 22 patients (31.9%), nondiagnostic lung mass in 9 patients (13.0%) and lung abscess in 5 patients (7.3%). The surgical procedures were lobectomy in 45 (65.2%) patients, pneumonectomy in 10 (14.5%) patients, bilobectomy in 8 (11.6%) patients, lobectomy plus segmentectomy in 3 (4.3%) patients and only segmentectomy in 3 (4.3%) patients. Morbidity rate was 14.5% and there was no perioperative mortality. The follow-up was possible in 60 patients, with an outcome reported as excellent in 44 (73.3%) patients, as improved in 11 (18.3%) and as unchanged in 5 (8.3%).

CONCLUSION

Although the number of patients with bronchiectasis referred for surgical treatment has decreased, pulmonary resection still plays a significant role. Surgical resection of localized bronchiectasis is a safe procedure with proven improvement of quality of life for the majority of patients.

A Mayan founder mutation is a common cause of deafness in Guatemala

Over 5% of the world's population has varying degrees of hearing loss. Mutations in GJB2 are the most common cause of autosomal recessive non-syndromic hearing loss (ARNHL) in many populations. The frequency and type of mutations are influenced by ethnicity. Guatemala is a multi-ethnic country with four major populations: Maya, Ladino, Xinca, and Garifuna. To determine the mutation profile of GJB2 in a ARNHL population from Guatemala, we sequenced both exons of GJB2 in 133 unrelated families. A total of six pathogenic variants were detected. The most frequent pathogenic variant is c.131G>A (p.Trp44*) detected in 21 of 266 alleles. We show that c.131G>A is associated with a conserved haplotype in Guatemala suggesting a single founder. The majority of Mayan population lives in the west region of the country from where all c.131G>A carriers originated. Further analysis of genome-wide variation of individuals carrying the c.131G>A mutation compared with those of Native American, European, and African populations shows a close match with the Mayan population.

Does postoperative radiation therapy represent a contraindication to expander-implant based immediate breast reconstruction? An update 2012-2014

OBJECTIVE

Post-mastectomy radiotherapy (PMRT) is well known in the plastic surgery community for having a negative impact on expander-implant based immediate breast reconstruction (IBBR), although recently some technical improvements allow better results. Very recent papers would suggest that there is no difference in postoperative complications in patients receiving post-mastectomy radiotherapy using modern techniques. However, study results are often biased by small groups of patients and by heterogeneity of radiotherapy timing, different surgical techniques and measured outcomes.

MATERIALS AND METHODS

We have conducted a MEDLINE search to summarize the latest data (2012-2014) on the topic. Search was conducted using the following parameters: breast reconstruction AND implant AND expander AND post-mastectomy radiotherapy.

RESULTS

The MEDLINE search showed 53 reports, demonstrating a great interest on this topic; among these 37 dealed specifically with post-mastectomy radiotherapy after breast reconstruction. In particular, 15 were amenable to plastic surgeons, 6 to breast surgeons, 9 to radiotherapists and 7 to oncologists. Papers amenable to plastic surgeons highlighted the highest rate of undesired results, although with recent advances such as delayed-immediate reconstruction or protective lipofilling.

CONCLUSIONS

PMRT remains an undesired event when pursuing an implant-based breast reconstruction, although it does not represent an absolute contraindication. The higher rate of complications reported by plastic surgeons and not by other specialists can be explained with the greater attention to aesthetic details, such as capsular contractures, that our community has. Technical strategies to prevent complications described in this community now allow better results, should be well known and improved if possible in the future.

Microscopy and X-ray spectroscopy analyses for assessment of gilding and silvering techniques of Portuguese illuminated manuscripts

The objects of this study are various local charters (cartas de foral, in Portuguese) granted by Dom Manuel I, King of Portugal (1495-1521), which substituted for medieval ones and were intended to achieve an administrative unification. These are luxuriously illuminated manuscripts, and our study aims at obtaining a better understanding of the gilding and silvering techniques applied to the parchments, in which the forais were written, between 1500 and 1520. The combined use of microscopy and X-ray spectroscopy analyses allowed us to identify the vestigial materials used for making the parchments, including products such as salt (NaCl), lime (CaO), pumice stone (SiO2+Al2O3), and chalk (CaCO3). Chalk was employed as a whitening agent to give the parchment its final color and opacity. Shell-gold and shell-silver mixed in with animal glue or gum binding media were directly applied on type 1 and 3 forais, while very thin gold leaves (<1 µm) were applied over lead-based tempera grounds (50-180 µm thick) in type 2 forais. Silver was always employed in its finest form without a further protective layer (thus its recursive state of corrosion), while gold was used in various alloy grades.

Micro-analytical study of a rare papier-mâché sculpture

The analysis of a Portuguese "papier-mâché" sculpture depicting Saint Anthony is presented in this case study. Several questions were addressed such as the characteristics of the support, pigments used, and artistic technique in order to establish a possible timeline for its production. Qualitative analyses of the cross-sections and of the paper support were performed by optical microscopy using reflected light. Two polychrome layers from different periods and a rag pulped support were identified on the sculpture. The use of micro X-ray fluorescence and Raman microscopy techniques enabled the differentiation of coloring materials used in both polychromies. Semi-quantitative analyses of the gilded samples were also performed by scanning electron microscopy in combination with energy-dispersive spectroscopy allowing the determination of a common Au-Ag-Cu alloy with differences in the purity of the gold. The identified coloring materials lead us to believe that the sculpture was produced in the 19th century, being overpainted in the first half of the 20th century.

Development of a combined portable x-ray fluorescence and Raman spectrometer for in situ analysis

In this work, we have built a portable X-ray fluorescence (XRF) spectrometer in a planar configuration coupled to a Raman head and a digital optical microscope, for in situ analysis. Several geometries for the XRF apparatus and digital microscope are possible in order to overcome spatial constraints and provide better measurement conditions. With this combined spectrometer, we are now able to perform XRF and Raman measurements in the same point without the need for sample collection, which can be crucial when dealing with cultural heritage objects, as well as forensic analysis. We show the capabilities of the spectrometer by measuring several standard reference materials, as well as other samples usually encountered in cultural heritage, geological, as well as biomedical studies.