X-ray radio-enhancement by Ti3C2Tx MXenes in soft tissue sarcoma

Radiotherapy is a cornerstone of cancer treatment. However, due to the low tissue specificity of ionizing radiation, damage to the surrounding healthy tissue of the tumor remains a significant challenge. In recent years, radio-enhancers based on inorganic nanomaterials have gained considerable interest. Beyond the widely explored metal and metal oxide nanoparticles, 2D materials, such as MXenes, could present potential benefits because of their inherently large specific surface area. In this study, we highlight the promising radio-enhancement properties of Ti3C2Tx MXenes. We demonstrate that atomically thin layers of titanium carbides (Ti3C2Tx MXenes) are efficiently internalized and well-tolerated by mammalian cells. Contrary to MXenes suspended in aqueous buffers, which fully oxidize within days, yielding rice-grain shaped rutile nanoparticles, the MXenes internalized by cells oxidize at a slower rate. This is consistent with cell-free experiments that have shown slower oxidation rates in cell media and lysosomal buffers compared to dispersants without antioxidants. Importantly, the MXenes exhibit robust radio-enhancement properties, with dose enhancement factors reaching up to 2.5 in human soft tissue sarcoma cells, while showing no toxicity to healthy human fibroblasts. When compared to oxidized MXenes and commercial titanium dioxide nanoparticles, the intact 2D titanium carbide flakes display superior radio-enhancement properties. In summary, our findings offer evidence for the potent radio-enhancement capabilities of Ti3C2Tx MXenes, marking them as a promising candidate for enhancing radiotherapy.

Multiscale multimodal characterization and simulation of structural alterations in failed bioprosthetic heart valves

Calcific degeneration is the most frequent type of heart valve failure, with rising incidence due to the ageing population. The gold standard treatment to date is valve replacement. Unfortunately, calcification oftentimes re-occurs in bioprosthetic substitutes, with the governing processes remaining poorly understood. Here, we present a multiscale, multimodal analysis of disturbances and extensive mineralisation of the collagen network in failed bioprosthetic bovine pericardium valve explants with full histoanatomical context. In addition to highly abundant mineralized collagen fibres and fibrils, calcified micron-sized particles previously discovered in native valves were also prevalent on the aortic as well as the ventricular surface of bioprosthetic valves. The two mineral types (fibres and particles) were detectable even in early-stage mineralisation, prior to any macroscopic calcification. Based on multiscale multimodal characterisation and high-fidelity simulations, we demonstrate that mineral occurrence coincides with regions exposed to high haemodynamic and biomechanical indicators. These insights obtained by multiscale analysis of failed bioprosthetic valves serve as groundwork for the evidence-based development of more durable alternatives. STATEMENT OF SIGNIFICANCE: Bioprosthetic valve calcification is a well-known clinically significant phenomenon, leading to valve failure. The nanoanalytical characterisation of bioprosthetic valves gives insights into the highly abundant, extensive calcification and disorganization of the collagen network and the presence of calcium phosphate particles previously reported in native cardiovascular tissues. While the collagen matrix mineralisation can be primarily attributed to a combination of chemical and mechanical alterations, the calcified particles are likely of host cellular origin. This work presents a straightforward route to mineral identification and characterization at high resolution and sensitivity, and with full histoanatomical context and correlation to hemodynamic and biomechanical indicators, hence providing design cues for improved bioprosthetic valve alternatives.

Metal-Organic Framework Mediated Radio-Enhancement Assessed in High-Throughput-Compatible 3D Tumor Spheroid Co-Cultures

Inorganic nanomaterials have gained increasing attention in radiation oncology, owing to their radiation therapy enhancing properties. To accelerate candidate material selection and overcome the disconnect between conventional 2D cell culture and in vivo findings, screening platforms unifying high-throughput with physiologically relevant endpoint analysis based on 3D in vitro models are promising. Here, a 3D tumor spheroid co-culture model based on cancerous and healthy human cells is presented for the concurrent assessment of radio-enhancement efficacy, toxicity, and intratissural biodistribution with full ultrastructural context of radioenhancer candidate materials. Its potential for rapid candidate materials screening is showcased based on the example of nano-sized metal-organic frameworks (nMOFs) and direct benchmarking against gold nanoparticles (the current "gold standard"). Dose enhancement factors (DEFs) ranging between 1.4 and 1.8 are measured for Hf-, Ti-, TiZr-, and Au-based materials in 3D tissues and are overall lower than in 2D cell cultures, where DEF values exceeding 2 are found. In summary, the presented co-cultured tumor spheroid-healthy fibroblast model with tissue-like characteristics may serve as high-throughput platform enabling rapid, cell line-specific endpoint analysis for therapeutic efficacy and toxicity assessment, as well as accelerated radio-enhancer candidate screening.

Multiscale Multimodal Investigation of the Intratissural Biodistribution of Iron Nanotherapeutics with Single Cell Resolution Reveals Co-Localization with Endogenous Iron in Splenic Macrophages

Imaging of iron-based nanoparticles (NPs) remains challenging because of the presence of endogenous iron in tissues that is difficult to distinguish from exogenous iron originating from the NPs. Here, an analytical cascade for characterizing the biodistribution of biomedically relevant iron-based NPs from the organ scale to the cellular and subcellular scales is introduced. The biodistribution on an organ level is assessed by elemental analysis and quantification of magnetic iron by electron paramagnetic resonance, which allowed differentiation of exogenous and endogenous iron. Complementary to these bulk analysis techniques, correlative whole-slide optical and electron microscopy provided spatially resolved insight into the biodistribution of endo- and exogenous iron accumulation in macrophages, with single-cell and single-particle resolution, revealing coaccumulation of iron NPs with endogenous iron in splenic macrophages. Subsequent transmission electron microscopy revealed two types of morphologically distinct iron-containing structures (exogenous nanoparticles and endogenous ferritin) within membrane-bound vesicles in the cytoplasm, hinting at an attempt of splenic macrophages to extract and recycle iron from exogenous nanoparticles. Overall, this strategy enables the distinction of endo- and exogenous iron across scales (from cm to nm, based on the analysis of thousands of cells) and illustrates distribution on organ, cell, and organelle levels.

The Role of Inorganics in Preeclampsia Assessed by Multiscale Multimodal Characterization of Placentae

Preeclampsia is one of the most dangerous diseases in pregnancy. Because of the hypertensive nature of preeclampsia, placental calcifications are believed to be a predictor for its occurrence, analogous to their role in cardiovascular diseases. However, the prevalence and the relevance of calcifications for the clinical outcome with respect to preeclampsia remains controversial. In addition, the role of other inorganic components present in the placental tissue in the development of preeclampsia has rarely been investigated. In this work, we therefore characterized inorganic constituents in placental tissue in groups of both normotensive and preeclamptic patients (N = 20 each) using a multi-scale and multi-modal approach. Examinations included elemental analysis (metallomics), sonography, computed tomography (CT), histology, scanning electron microscopy, X-ray fluorescence and energy dispersive X-ray spectroscopy. Our data show that tissue contents of several heavy metals (Al, Cd, Ni, Co, Mn, Pb, and As) were elevated whereas the Rb content was decreased in preeclamptic compared to normotensive placentae. However, the median mineral content (Ca, P, Mg, Na, K) was remarkably comparable between the two groups and CT showed lower calcified volumes and fewer crystalline deposits in preeclamptic placentae. Electron microscopy investigations revealed four distinct types of calcifications, all predominantly composed of calcium, phosphorus and oxygen with variable contents of magnesium in tissues of both maternal and fetal origin in both preeclamptic and normotensive placentae. In conclusion our study suggests that heavy metals, combined with other factors, can be associated with the development of preeclampsia, however, with no obvious correlation between calcifications and preeclampsia.

Nuclear and cellular, micro and nano calcification in Alzheimer's disease patients and correlation to phosphorylated Tau

Brain calcification (calcium phosphate mineral formation) has been reported in the past 100 years in the brains of Alzheimer's disease (AD) patients. However, the association between calcification and AD, the triggers for calcification, and its role within the disease are not clear. On the other hand, hyperphosphorylated Tau protein (pTau) tangles have been widely studied and recognized as an essential factor in developing AD. In this work, calcification in the brains of AD patients is characterized by advanced electron microscopy and fluorescence microscopy. Results are then compared to samples from cognitively healthy, age-matched donors, and the colocalization of calcification and pTau is investigated. Here, we show that AD patients' brains present microcalcification associated with the neural cell nuclei and cell projections, and that these are strongly related to the presence of pTau. The link between microcalcification and pTau suggests a potential mechanism of brain cell damage. Together with the formation of amyloid plaques and neurofibrillary tangles, microcalcification in neuronal cells adds to a better understanding of the pathology of AD. Finally, the presence of microcalcification in the neuronal cells of AD patients may assist in AD diagnosis, and may open avenues for developing intervention strategies based on inhibition of calcification. STATEMENT OF SIGNIFICANCE: Brain calcification has been reported in the past 100 years in the brains of Alzheimer's disease (AD) patients. However, the association between calcification and AD is not clear. Hyperphosphorylated Tau protein (pTau) has been studied and recognized as a key factor in developing AD. We show here that AD patients' brains present microcalcification associated with the neuronal cell nuclei and cell projections, and that these are related to the presence of pTau. The study of calcification in brain cells can contribute to a better understanding of the biochemical mechanisms associated with AD and might also reveal that calcification is part of the full disease mechanism. Moreover, this work opens the possibility for using calcification as a biomarker to identify AD.

Annexin A1-dependent tethering promotes extracellular vesicle aggregation revealed with single-extracellular vesicle analysis

Extracellular vesicles (EVs) including plasma membrane-derived microvesicles and endosomal-derived exosomes aggregate by unknown mechanisms, forming microcalcifications that promote cardiovascular disease, the leading cause of death worldwide. Here, we show a framework for assessing cell-independent EV mechanisms in disease by suggesting that annexin A1 (ANXA1)-dependent tethering induces EV aggregation and microcalcification. We present single-EV microarray, a method to distinguish microvesicles from exosomes and assess heterogeneity at a single-EV level. Single-EV microarray and proteomics revealed increased ANXA1 primarily on aggregating and calcifying microvesicles. ANXA1 vesicle aggregation was suppressed by calcium chelation, altering pH, or ANXA1 neutralizing antibody. ANXA1 knockdown attenuated EV aggregation and microcalcification formation in human cardiovascular cells and acellular three-dimensional collagen hydrogels. Our findings explain why microcalcifications are more prone to form in vulnerable regions of plaque, regulating critical cardiovascular pathology, and likely extend to other EV-associated diseases, including autoimmune and neurodegenerative diseases and cancer.

Multiscale Analysis of Metal Oxide Nanoparticles in Tissue: Insights into Biodistribution and Biotransformation

Metal oxide nanoparticles have emerged as exceptionally potent biomedical sensors and actuators due to their unique physicochemical features. Despite fascinating achievements, the current limited understanding of the molecular interplay between nanoparticles and the surrounding tissue remains a major obstacle in the rationalized development of nanomedicines, which is reflected in their poor clinical approval rate. This work reports on the nanoscopic characterization of inorganic nanoparticles in tissue by the example of complex metal oxide nanoparticle hybrids consisting of crystalline cerium oxide and the biodegradable ceramic bioglass. A validated analytical method based on semiquantitative X-ray fluorescence and inductively coupled plasma spectrometry is used to assess nanoparticle biodistribution following intravenous and topical application. Then, a correlative multiscale analytical cascade based on a combination of microscopy and spectroscopy techniques shows that the topically applied hybrid nanoparticles remain at the initial site and are preferentially taken up into macrophages, form apatite on their surface, and lead to increased accumulation of lipids in their surroundings. Taken together, this work displays how modern analytical techniques can be harnessed to gain unprecedented insights into the biodistribution and biotransformation of complex inorganic nanoparticles. Such nanoscopic characterization is imperative for the rationalized engineering of safe and efficacious nanoparticle-based systems.

The multiscale hierarchical structure of Heloderma suspectum osteoderms and their mechanical properties

Osteoderms are hard tissues embedded in the dermis of vertebrates and have been suggested to be formed from several different mineralized regions. However, their nano architecture and micro mechanical properties had not been fully characterized. Here, using electron microscopy, µ-CT, atomic force microscopy and finite element simulation, an in-depth characterization of osteoderms from the lizard Heloderma suspectum, is presented. Results show that osteoderms are made of three different mineralized regions: a dense apex, a fibre-enforced region comprising the majority of the osteoderm, and a bone-like region surrounding the vasculature. The dense apex is stiff, the fibre-enforced region is flexible and the mechanical properties of the bone-like region fall somewhere between the other two regions. Our finite element analyses suggest that when combined into the osteoderm structure, the distinct tissue regions are able to shield the body of the animal by bearing the external forces. These findings reveal the structure-function relationship of the Heloderma suspectum osteoderm in unprecedented detail. STATEMENT OF SIGNIFICANCE: The structures of bone and teeth have been thoroughly investigated. They provide a basis not only for understanding the mechanical properties and functions of these hard tissues, but also for the de novo design of composite materials. Osteoderms, however, are hard tissues that must possess mechanical properties distinct from teeth and bone to function as a protective armour. Here we provide a detailed analysis of the nanostructure of vertebrate osteoderms from Heloderma suspectum, and show that their mechanical properties are determined by their multiscale hierarchical tissue. We believe this study contributes to advance the current knowledge of the structure-function relationship of the hierarchical structures in the Heloderma suspectum osteoderm. This knowledge might in turn provide a source of inspiration for the design of bioinspired and biomimetic materials.

Nano-analytical characterization of endogenous minerals in healthy placental tissue: mineral distribution, composition and ultrastructure

Despite its crucial role, the placenta is the least understood human organ. Recent clinical studies indicate a direct association between placental calcification and maternal and offspring health. This study reveals distinct characteristics of minerals formed during gestational ageing using cutting-edge nano-analytical characterization and paves the way for investigations focused on the identification of potential markers for disease risks in a clinical setting based on atypical placental mineral fingerprints.

Calcified nodules in retinal drusen are associated with disease progression in age-related macular degeneration

Drusen are lipid-, mineral-, and protein-containing extracellular deposits that accumulate between the basal lamina of the retinal pigment epithelium (RPE) and Bruch's membrane (BrM) of the human eye. They are a defining feature of age-related macular degeneration (AMD), a common sight-threatening disease of older adults. The appearance of heterogeneous internal reflectivity within drusen (HIRD) on optical coherence tomography (OCT) images has been suggested to indicate an increased risk of progression to advanced AMD. Here, in a cohort of patients with AMD and drusen, we show that HIRD indicated an increased risk of developing advanced AMD within 1 year. Using multimodal imaging in an independent cohort, we demonstrate that progression to AMD was associated with increasing degeneration of the RPE overlying HIRD. Morphological analysis of clinically imaged cadaveric human eye samples revealed that HIRD was formed by multilobular nodules. Nanoanalytical methods showed that nodules were composed of hydroxyapatite and that they differed from spherules and BrM plaques, other refractile features also found in the retinas of patients with AMD. These findings suggest that hydroxyapatite nodules may be indicators of progression to advanced AMD and that using multimodal clinical imaging to determine the composition of macular calcifications may help to direct therapeutic strategies and outcome measures in AMD.

An engineered, quantifiable in vitro model for analysing the effect of proteostasis-targeting drugs on tissue physical properties

Cellular function depends on the maintenance of protein homeostasis (proteostasis) by regulated protein degradation. Chronic dysregulation of proteostasis is associated with neurodegenerative and age-related diseases, and drugs targeting components of the protein degradation apparatus are increasingly used in cancer therapies. However, as chronic imbalances rather than loss of function mediate their pathogenesis, research models that allow for the study of the complex effects of drugs on tissue properties in proteostasis-associated diseases are almost completely lacking. Here, to determine the functional effects of impaired proteostatic fine-tuning, we applied a combination of materials science characterisation techniques to a cell-derived, in vitro model of bone-like tissue formation in which we pharmacologically perturbed protein degradation. We show that low-level inhibition of VCP/p97 and the proteasome, two major components of the degradation machinery, have remarkably different effects on the bone-like material that human bone-marrow derived mesenchymal stromal cells (hMSC) form in vitro. Specifically, whilst proteasome inhibition mildly enhances tissue formation, Raman spectroscopic, atomic force microscopy-based indentation, and electron microscopy imaging reveal that VCP/p97 inhibition induces the formation of bone-like tissue that is softer, contains less protein, appears to have more crystalline mineral, and may involve aberrant micro- and ultra-structural tissue organisation. These observations contrast with findings from conventional osteogenic assays that failed to identify any effect on mineralisation. Taken together, these data suggest that mild proteostatic impairment in hMSC alters the bone-like material they form in ways that could explain some pathologies associated with VCP/p97-related diseases. They also demonstrate the utility of quantitative materials science approaches for tackling long-standing questions in biology and medicine, and could form the basis for preclinical drug testing platforms to develop therapies for diseases stemming from perturbed proteostasis or for cancer therapies targeting protein degradation. Our findings may also have important implications for the field of tissue engineering, as the manufacture of cell-derived biomaterial scaffolds may need to consider proteostasis to effectively replicate native tissues.

Scanning electron microscopy for blood micro-crystals in aortic stenosis patients

BACKGROUND

Micro-crystals of calcium phosphate have been detected on the aortic valve of patients with aortic stenosis using scanning electron microscopy. It is not known whether crystalisation is specific to heart valve tissue or a general blood-derived process.

METHODS

To this end we modified the method to determine whether calcium phosphate micro-crystals were present in the blood of patients with aortic stenosis. The method was first validated by adding synthetic calcium phosphate hydroxyapatite micro-crystals to healthy volunteer blood samples and determining the lower limit of detection. Then the method was used to examine the blood of 63 patients with echocardiographically confirmed aortic stenosis and 69 unaffected controls undergoing echocardiography for other reasons. Serum calcium and phosphate were measured and the calcium phosphate product compared in cases and controls.

RESULTS

In the validation study, synthetic hydroxyapatite micro-crystals were identified down to a lower concentration limit of 0.008mg/mL. In the experimental study no particles were identified in any patient, with or without aortic stenosis, even though serum calcium phosphate was higher in cases compared with controls 2.6mmol/L (2.58-2.77) versus 2.47mmol/L (2.36-2.57), p = 0.005 for the difference.

CONCLUSION

The results of our study confirm a positive association between serum calcium phosphate and aortic stenosis, but indicate that the calcium phosphate particles found in valve tissue do not precipitate freely in the blood.

Facile meltPEGylation of flame-made luminescent Tb3+-doped yttrium oxide particles: hemocompatibility, cellular uptake and comparison to silica

MeltPEGylation constitutes an elegant one-pot route for the efficient PEGylation of metal oxide nanoparticles with improved hemo- and cytocompatibility.

Removal of Cells from Body Fluids by Magnetic Separation in Batch and Continuous Mode: Influence of Bead Size, Concentration, and Contact Time

The magnetic separation of pathogenic compounds from body fluids is an appealing therapeutic concept. Recently, removal of a diverse array of pathogens has been demonstrated using extracorporeal dialysis-type devices. The contact time between the fluid and the magnetic beads in such devices is limited to a few minutes. This poses challenges, particularly if large compounds such as bacteria or cells need to be removed. Here, we report on the feasibility to remove cells from body fluids in a continuous dialysis type of setting. We assessed tumor cell removal efficiencies from physiological fluids with or without white blood cells using a range of different magnetic bead sizes (50-4000 nm), concentrations, and contact times. We show that tumor cells can be quantitatively removed from body fluids within acceptable times (1-2 min) and bead concentrations (0.2 mg per mL). We further present a mathematical model to describe the minimal bead number concentration needed to remove a certain number of cells, in the presence of competing nonspecific uptake. The present study paves the way for investigational studies to assess the therapeutic potential of cell removal by magnetic blood purification in a dialysis-like setting.

Abstract P6-09-07: Mutation characteristics and tumor infiltrating lymphocytes in early and metastatic HER2-positive breast cancer

Background-aim: HER2-positive breast cancer (BC) features high rates of tumor infiltrating lymphocytes (TILs) and mutations (mut) in various genes, more frequently in TP53. We investigated associations between TILs and mutations in HER2-positive BC and their impact on patient outcome in early and metastatic BC (EBC and MBC, respectively), which remain largely unexplored.

Methods:In 352 primary paraffin tumors from patients with HER2-positive disease, we examined amino acid changing mutations (<0.1% minor allele frequency) in 58 genes for type and possible clonality (>20% variant frequency). Study groups were: (A) 218 EBC, including 117 patients treated with adjuvant chemotherapy only (CT) and 101 patients treated with CT and trastuzumab (CTT); (B) 134 MBC, including 95 patients who relapsed upon adjuvant CT without trastuzumab (R-MBC) and 39 patients who were first diagnosed with metastatic disease (de novo MBC). TILs were assessed as percentage of stromal tumor area. Clinical endpoints were disease-free survival in 5 years (5yr DFS) for EBC, and time-to-progression (TTP) from 1st line CTT treatment start for MBC.

Results: 243/352 tumors (69%) carried at least one mut; 27/352 (8%) of tumors >10 up to 150 mut (hypermut); 192/352 (54%) at least one possibly clonal mut. Mean mut number and TP53 mut in particular were highest in R-MBC and lowest in EBC; mean TILs density followed the opposite pattern (all p<0.001). TILs density was lower in all settings in hypermut tumors and in tumors with multiple clonal mut (p values 0.043 – 0.050). Upon multivariate analysis in EBC, higher risk for relapse in 5yrs was noticed for CT patients compared to CTT (odds ratio [OR] 2.39, 95%CI [CI] 1.13-5.04, p=0.023) and for >3 compared to 0-3 positive nodes (OR 3.83, CI 1.76-8.34, p=0.001); lower risk for relapse was observed for higher TILs irrespectively of treatment (OR 0.93, CI 0.90-0.97, p=0.001), for TP53 mut (OR 0.39, CI 0.18-0.87, p=0.022) and for clonal TP53 mut in CTT-treated patients (OR 0.10, CI 0.02-0.58) but not in CT-treated patients (interaction p=0.084). The presence of any clonal mut (hazard ratio [HR] 2.77, CI 1.42-5.38) and of clonal TP53 mut (HR 2.24, CI 1.20-4.17) conferred worse TTP in de novo but not in R-MBC; these interactions remained significant upon multivariate analysis (interaction p=0.007 and p=0.061, respectively). Higher TILs in the absence of clonal mut conferred longer TTP (HR 0.75, CI 0.56-0.99) but no such effect was observed for tumors with clonal mut (multivariate interaction p=0.052). Classic independent predictors of unfavorable TTP in MBC were younger age (p=0.002), absence of hormone receptors (p=0.001) and poor performance status (p=0.044). PIK3CA mut did not remain significant in any of the examined settings.

Conclusions: The expected pattern of higher TILs associated with mutation number and clonality was not observed in HER2-positive BC; the favorable effect of TILs only in the absence of clonal mut in MBC may imply exhausted immune response. Clonal TP53 mut may serve as a predictor for trastuzumab benefit in EBC but as an adverse prognosticator in trastuzumab-treated de novo MBC, which, if further validated, is of potential clinical relevance.Background-aim: HER2-positive breast cancer (BC) features high rates of tumor infiltrating lymphocytes (TILs) and mutations (mut) in various genes, more frequently in TP53. We investigated associations between TILs and mutations in HER2-positive BC and their impact on patient outcome in early and metastatic BC (EBC and MBC, respectively), which remain largely unexplored.

Methods:In 352 primary paraffin tumors from patients with HER2-positive disease, we examined amino acid changing mutations (<0.1% minor allele frequency) in 58 genes for type and possible clonality (>20% variant frequency). Study groups were: (A) 218 EBC, including 117 patients treated with adjuvant chemotherapy only (CT) and 101 patients treated with CT and trastuzumab (CTT); (B) 134 MBC, including 95 patients who relapsed upon adjuvant CT without trastuzumab (R-MBC) and 39 patients who were first diagnosed with metastatic disease (de novo MBC). TILs were assessed as percentage of stromal tumor area. Clinical endpoints were disease-free survival in 5 years (5yr DFS) for EBC, and time-to-progression (TTP) from 1st line CTT treatment start for MBC.

Results: 243/352 tumors (69%) carried at least one mut; 27/352 (8%) of tumors >10 up to 150 mut (hypermut); 192/352 (54%) at least one possibly clonal mut. Mean mut number and TP53 mut in particular were highest in R-MBC and lowest in EBC; mean TILs density followed the opposite pattern (all p<0.001). TILs density was lower in all settings in hypermut tumors and in tumors with multiple clonal mut (p values 0.043 – 0.050). Upon multivariate analysis in EBC, higher risk for relapse in 5yrs was noticed for CT patients compared to CTT (odds ratio [OR] 2.39, 95%CI [CI] 1.13-5.04, p=0.023) and for >3 compared to 0-3 positive nodes (OR 3.83, CI 1.76-8.34, p=0.001); lower risk for relapse was observed for higher TILs irrespectively of treatment (OR 0.93, CI 0.90-0.97, p=0.001), for TP53 mut (OR 0.39, CI 0.18-0.87, p=0.022) and for clonal TP53 mut in CTT-treated patients (OR 0.10, CI 0.02-0.58) but not in CT-treated patients (interaction p=0.084). The presence of any clonal mut (hazard ratio [HR] 2.77, CI 1.42-5.38) and of clonal TP53 mut (HR 2.24, CI 1.20-4.17) conferred worse TTP in de novo but not in R-MBC; these interactions remained significant upon multivariate analysis (interaction p=0.007 and p=0.061, respectively). Higher TILs in the absence of clonal mut conferred longer TTP (HR 0.75, CI 0.56-0.99) but no such effect was observed for tumors with clonal mut (multivariate interaction p=0.052). Classic independent predictors of unfavorable TTP in MBC were younger age (p=0.002), absence of hormone receptors (p=0.001) and poor performance status (p=0.044). PIK3CA mut did not remain significant in any of the examined settings.

Conclusions: The expected pattern of higher TILs associated with mutation number and clonality was not observed in HER2-positive BC; the favorable effect of TILs only in the absence of clonal mut in MBC may imply exhausted immune response. Clonal TP53 mut may serve as a predictor for trastuzumab benefit in EBC but as an adverse prognosticator in trastuzumab-treated de novo MBC, which, if further validated, is of potential clinical relevance.

Citation Format: Kotoula V, Giannoulatou E, Kouvatseas G, Tikas I, Lazaridis G, Charalambous E, Efstratiou I, Bobos M, Tsolaki E, Zagouri F, Christodoulou C, Pentheroudakis G, Koutras A, Papakostas P, Kosmidis PA, Pectasides D, Fountzilas G. Mutation characteristics and tumor infiltrating lymphocytes in early and metastatic HER2-positive breast cancer [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 P6-09-07.

Abstract P4-14-05: Genomic parameters affecting the outcome of patients with advanced breast cancer treated with trastuzumab

Background-Aim: There is an unmet need for de-selecting HER2-positive patients with advanced breast cancer (ABC), since only some of those patients benefit from the addition of anti-HER2 agents to chemotherapy. The aim of this study was to investigate candidate biomarkers, including MYC and MET, in parallel with an extended array of biomarkers previously associated with trastuzumab (T) resistance.

Patients and Methods: Two hundred and twenty-nine ABC patients treated with T and chemotherapy over a period of 13 years were included in the study. Paraffin tumors were retrospectively centrally assessed with immunohistochemistry (IHC) for breast cancer subtypes; fluorescence in situ hybridization (FISH) for HER2, TOP2A and centromere (CEN) 17, MYC and CEN8, MET and CEN7; qPCR for MYC and MET copy number (CN); and, for PI3K activation (PIK3CA mutations, PTEN and phospho-mTOR IHC). Patterns of CEN CN aberrations corresponding to chromosome "polysomy" were also evaluated, with cut-offs based on normal tissue. Time to progression (TTP) and survival were evaluated from the initiation of T as first-line treatment.

Results: Median follow-up was 70 months. Of the 229 patients treated with T as HER2-positive, central analysis identified 90 cases being HER2-negative, as per current guidelines (39.3% of the total cohort). HER2-positive patients showed a trend for survival benefit over HER2-negative patients (median 50.7 vs. 38.1 months, respectively, p=0.118). HER2-positive tumors were subtyped as Luminal-HER2 (n=77) and HER2-enriched (n=53); 156 patients presented with ABC and 65 with disease initially diagnosed at stage IV (de novo ABC). MET and MYC CN gains (≥2.5 copies) were found in 40 (25%) and 15 (9%) cases with qPCR, while MET and MYC amplification with FISH was present in 4 (2.5%) and 31 (18%) cases, respectively. Concordance between FISH and qPCR was low for MYC (kappa value 0.46) and absent for MET. Polysomy was collectively observed in 70 cases, in 54 of them (32% of all tumors) concerning any 1 of the 3 examined chromosomes. This condition, called restricted polysomy, interacted with ABC presentation, conferring decreased survival to patients with ABC (HR=2.32, 95% CI 1.43-3.76, Wald's p=0.001) but not to those with de novo ABC (interaction p=0.077). MYC CN gain was the only marker significantly associated with increased risk for progression (HR=3.22, 95% CI 1.66-6.24, p<0.001) and death (HR=5.45, 95% CI 2.89-10.28, p<0.001) at univariate analysis. Adjustment of all tested markers with standard clinicopathological parameters revealed that along with poor patient performance status that was associated with poor prognosis, MYC CN gain was an independent adverse prognosticator for both TTP and survival (all p-values <0.001). The HER2-enriched subtype was independently associated with T benefit for TTP (p=0.001) and survival (p=0.051). The interaction between restricted polysomy and disease presentation was also independently significant for survival (p=0.041).

Conclusions: MYC CN gain is a strong unfavorable prognosticator in T-treated ABC patients. Distinguishing between HER2-positive subtypes seems important for identifing T benefit in ABC. Chromosomal polysomy may distinctly affect T benefit in patients with pre-treated and de novo ABC.

Citation Format: Gogas H, Kotoula V, Alexopoulou Z, Christodoulou C, Kostopoulos I, Bobos M, Raptou G, Charalambous E, Tsolaki E, Xanthakis I, Pentheroudakis G, Koutras A, Bafaloukos D, Papakostas P, Aravantinos G, Psyrri A, Petraki K, Kalogeras KT, Fountzilas G, Pectasides D. Genomic parameters affecting the outcome of patients with advanced breast cancer treated with trastuzumab. [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 P4-14-05.

Abstract P5-08-50: Associations of MYC protein expression and gene status with breast cancer subtypes and outcome in patients treated with anthracycline-based adjuvant chemotherapy

Background-Aim: Breast cancer is a heterogeneous disease and despite recent scientific progress there is still need for the identification of biomarkers associated with risk for relapse, as well as for markers identifying patients who will benefit from specific treatments. The aim of the present study was to investigate the role of MYC, as a clinically meaningful biomarker, in the outcome of breast cancer subtypes.

Patients and Methods: We have pooled the patients and the respective breast carcinomas from two randomized anthracycline-based adjuvant phase III trials, consecutively conducted by the Hellenic Cooperative Oncology Group (HE10/97 and HE10/00). The HE10/97 trial included a non-paclitaxel arm. Tissue microarrays were constructed from 1,060 formalin-fixed paraffin-embedded tumor tissue samples that were collected retrospectively in the first and prospectively in the second trial. MYC was evaluated by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in 986 cases.

Results: In total 61.0% of the cases showed positive cytoplasmic MYC immunostaining, while 26.5% showed positive nuclear staining. 65-80% of the patients were characterized as non-amplified or loss/normal-low gain in all FISH cut-offs examined. A weak association was observed between FISH and nuclear protein expression of MYC. High histological grade was associated with MYC protein overexpression and gene amplification. In terms of disease-free survival (DFS), low (2.5-5 copies) and high (≥5 copies) gain of MYC was of adverse prognostic value compared to loss/normal (<2.5 copies) MYC (HR=1.50, 95% CI 1.13-1.98, Wald's p=0.004 and HR=1.45, 95% CI 1.07-1.97, p=0.016, respectively). Comparable results were observed for overall survival (OS) (HR=1.51, 95% CI 1.09-2.08, p=0.013 and HR=1.65, 95% CI 1.17-2.33, p=0.005, respectively). The comparison of neoplasms with CEP8 ratio ≥1.3 and polysomy 8 for MYC versus all others resulted in worse survival prognosis (HR=1.44, 95% CI 1.13-1.83, p=0.004), while tumors with nuclear protein overexpression were associated with better DFS (HR=0.77, 95% CI 0.60-0.99, p=0.039) and OS (HR=0.73, 95% CI 0.55-0.98, p=0.034). In HER2-enriched patients, MYC amplification was found to be an adverse prognostic factor for DFS (HR=2.11, 95% CI 1.09-4.07, p=0.026) and OS (HR=2.41, 95% CI 1.12-5.15, p=0.024).

Treatment with paclitaxel was found to differentiate the effect of MYC: CEP8 ratio ≥1.3 and polysomy 8 in terms of DFS and OS in our total cohort. Among patients with CEP8 ratio ≥1.3 and polysomy 8, those treated with paclitaxel performed significantly better than those not treated, while among patients not treated with paclitaxel, those with CEP8 ratio ≥1.3 and polysomy 8 performed much worse than those with CEP8 ratio <1.3 or no polysomy 8.

Conclusions: Our data suggest that MYC has prognostic and predictive value in patients with breast cancer. MYC amplification and MYC protein overexpression are detected in breast cancer patients and are of adverse prognostic value for DFS and OS. Polysomy 8 is also associated with worse prognosis. Treatment with paclitaxel in the adjuvant setting benefits breast cancer patients with MYC:CEP8 ratio ≥1.3 and polysomy 8.

Citation Format: Batistatou A, Razis E, Bobos M, Tsolaki E, Timotheadou E, Alexopoulou Z, Goussia A, Gogas H, Koutras A, Karina M, Pentheroudakis G, Efstratiou I, Petraki K, Sotiropoulou M, Pavlakis K, Koletsa T, Kotoula V, Fountzilas G. Associations of MYC protein expression and gene status with breast cancer subtypes and outcome in patients treated with anthracycline-based adjuvant chemotherapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-50.

Selected heterocyclic compounds as antioxidants. Synthesis and biological evaluation

Reactive oxygen species, oxidative stress, and oxidative damage are increasingly assigned important roles as harmful factors in pathological conditions and ageing. ROS are potentially reactive molecules derived from the reduction of molecular oxygen in the course of aerobic metabolism. ROS can also be produced through a variety of enzymes. Under normal circumstances, ROS concentrations are tightly controlled by physiological antioxidants. When excessively produced, or when antioxidants are depleted, ROS can impose oxidative damage to lipids, proteins, sugars and DNA. This reduction-oxidation imbalance, called oxidative stress, can subsequently contribute to the development and progression of tissue damage and play a role in the pathology of various diseases. An antioxidant is defined as "any substance that, when present at low concentrations compared with those of a substrate, significantly delays, prevents or removes oxidative damage to this target molecule". Despite evidence that oxidative damage contributes to a wide range of clinically important conditions, few antioxidants act as effective drugs in vivo. Inter alia, the difficulty of measuring antioxidant efficacy in vivo makes the interpretation of results from clinical trials difficult. A large number of synthetic compounds have been reported to possess antioxidant activity. Several of them derive from natural antioxidants, others have various structures. In this review, some of the most often reported classes of heterocyclic antioxidant compounds, as well as methods for evaluation of their antioxidant activity are discussed.

Spectroscopic evaluation of glioma grading at 3T: the combined role of short and long TE

Purpose. To evaluate the diagnostic value of 3T ¹H-MRS in grading cerebral gliomas using short and long echo times. Methods. 1H-MRS was performed on 71 patients with untreated cerebral gliomas. Metabolite ratios of NAA/Cr, Cho/Cr, Cho/NAA, and mI/Cr were calculated for short and long TE and compared between low and high grade gliomas. Lipids were qualitatively evaluated. ROC analysis was performed to obtain the cut-off values for the metabolic ratios presenting statistical difference between the two glioma grades. Results. Intratumoral Cho/Cr at both TEs and long TE Cho/NAA were significantly different between low and high grade gliomas. Peritumoral NAA/Cr of both TEs, as well as long TE Cho/Cr and Cho/NAA ratios, significantly differentiated the two tumor grades. Diagnostic sensitivity of peritumoral short TE NAA/Cr proved to be superior over the other metabolic ratios, whereas intratumoral short TE Cho/Cr reached the highest levels of specificity and accuracy. Overall, short TE 1H-MRS reached higher total sensitivity in predicting glioma grade, over long TE. Conclusion. An advantage was found in using short TE over long TE 1H-MRS in the discrimination of low versus high grade gliomas. Moreover, the results suggested that the peritumoral area of gliomas may be more valuable in predicting glioma grade than using only the intratumoral area.

PD05-02: Effect of HER2/Topoisomerase II alpha (TOP2A) Gene Status or Protein Expression and Chromosome 17 (CEP17) Polysomy on the Outcome of Breast Cancer Patients Treated with Anthracycline-Containing Dose-Dense Sequential Adjuvant Chemotherapy with or without Paclitaxel – A Pooled Analysis of Two Hellenic Cooperative Oncology Group (HeCOG) Phase III Trials

Background: The HER2 gene has been established as a valid biomarker in the treatment of breast cancer patients with trastuzumab and probably with other agents, such as paclitaxel or anthracyclines. The TOP2A gene has been associated with response to anthracyclines. The relationship of HER2/TOP2A gene status in the presence of CEP17 polysomy with patients’ outcome following adjuvant treatment with anthracyclines with or without paclitaxel is not established.

Patients and methods: Formalin-fixed paraffin-embedded (FFPE) tumor tissue blocks from 1,033 patients (61.5% of 1,681 randomized patients) with high-risk operable breast cancer enrolled in two sequential phase III trials1,2 were assessed in a central laboratory for HER2/TOP2A gene amplification and CEP17 polysomy by fluorescence in situ hybridization (FISH) and tumors were categorized according to the 2007 American Society of Clinical Oncology/College of American Pathologists guidelines. HER2 and TOP2A amplification was defined as a gene/CEP17 ratio of >=2.2 and >=2.0, respectively or a gene copy number of >6. Additionally HER2, TOP2A, ER/PgR, Ki67, CK5 and EGFR protein expression were assessed by immunohistochemistry (IHC) and all patients were classified according to their IHC phenotype. Treatment consisted of epirubicin-based dose-dense sequential adjuvant chemotherapy followed by hormonal therapy and radiation, as indicated.

Results: Disease-free survival (DFS) and overall survival (OS) did not differ significantly between treatment groups. Median follow-up was 92 months, while 5-year DFS (OS) rates were 74% (88%), 69% (81%) and 75% (86%) for the E-T-CMF, E-CMF and ET-CMF groups, respectively. HER2 amplification was found in 24.1% of the patients and TOP2A amplification in 10.3%. In total, 46.7% of HER2 amplified tumors demonstrated TOP2A co-amplification. The median (range) of HER2, TOP2A and CEP17 copy numbers was 2.55 (0.70−45.15), 2.2 (0.50−26.15) and 2.05 (0.45−26.55), respectively. 21% of the tumors were considered to be polysomic (32.5% of those with HER2 amplification). Adjusting for treatment groups in the Cox model, TOP2A amplification, CEP17 polysomy and HER2/TOP2A co-amplification were not associated with either relapse or death. Treatment with paclitaxel was associated with improved survival in the HER2−amplified subgroup (HR=0.493, interaction p=0.036; adjusting for clinicopathological prognostic factors: HR=0.553, interaction p=0.054), an association that was not apparent for DFS. Conclusions: HER2 amplification was predictive for OS benefit from adjuvant treatment with paclitaxel in patients treated with epirubicin-based dose-dense sequential adjuvant chemotherapy, but not for DFS. TOP2A amplification, CEP17 polysomy and HER2/TOP2A co-amplification were not associated with outcome.

1. Ann Oncol 16:1762–71, 2005; 2. Ann Oncol 19:853–60, 2008.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD05-02.

Strengths and weaknesses of 1.5T and 3T MRS data in brain glioma classification

Although magnetic resonance spectroscopy (MRS) methods of 1.5Tesla (T) and 3T have been widely applied during the last decade for noninvasive diagnostic purposes, only a few studies have been reported on the value of the information extracted in brain cancer discrimination. The purpose of this study is threefold. First, to show that the diagnostic value of the information extracted from two different MRS scanners of 1.5T and 3T is significantly influenced in terms of brain gliomas discrimination. Second, to statistically evaluate the discriminative potential of publicly known metabolic ratio markers, obtained from these two types of scanners in classifying low-, intermediate-, and high-grade gliomas. Finally, to examine the diagnostic value of new metabolic ratios in the discrimination of complex glioma cases where the diagnosis is both challenging and critical. Our analysis has shown that although the information extracted from 3T MRS scanner is expected to provide better brain gliomas discrimination; some factors like the features selected, the pulse-sequence parameters, and the spectroscopic data acquisition methods can influence the discrimination efficiency. Finally, it is shown that apart from the bibliographical known, new metabolic ratio features such as N-acetyl aspartate/ S, Choline/ S, Creatine/ S , and myo-Inositol/ S play significant role in gliomas grade discrimination.

The CEAP-L classification for lymphedemas of the limbs: the Italian experience

AIM

A method to classificate lymphedema has been needed to gather all the important information on the clinical evolution of the disease using a common language and an easy clinical applicability.

METHODS

The proposal for a new classification of the limb lymphedema was inspired by the C.E.A.P. classification for chronic venous insufficiency of the lower limb. The classification adopts the acronym C.E.A.P. by adding the letter L to underline the aspect ''lymphedema'' and is based on clinical data such as extension of lymphedema, presence of lymphangitis, leg ulcers and loss of functionality of the limb and instrumental criteria that permit to confirm and precise diagnosis. The Clinical classification is based on the most objective sign in these patients, the edema which is subdivided into 5 classes depending on the clinical manifestations. The etiological aspect considers 2 types of alterations of the lymphatic system: congenital and acquired. The anatomic is aimed to locate the anatomical structures involved. Pathophysiological conditions are gathered into 5 groups: agenesia or hypoplasia, hyperplasia, reflux, overload, obstruction.

RESULTS

The classification has already been appraised after 4 years of activity at the unit of Vascular and Endovascular Surgery of Ferrara, at the S. Giovanni Battista Hospital in Rome, at the Umberto I Ancona Hospital and at the S. Giovanni-Addolorata Hospital in Rome.

CONCLUSIONS

The proposal for a new classification of lymphedema C.E.A.P. L was developed in order to categorize patients with definite and objective marks, creating clinical reports with a common vocabulary, clear to all clinicians, permitting to stage the disease, evaluate treatment and finally obtain epidemiological and statistical data.

Primary intravascular synovial sarcoma of the femoral vein in a male patient, case report

Synovial Sarcoma (SS) is an aggressive neoplasm commonly affecting deep soft tissues of the extremities. In rare instances SS can arise in large veins of the lower extremities or trunk. We report the first case of intravascular synovial sarcoma (IVSS) occurring in a male patient. A biphasic tumor was diagnosed by histology and immunohistochemistry. Molecular analysis at RNA level confirmed the diagnosis demonstrating the chromosomal translocation t(X;18) (p11.2;q11.2) in the tumor. Although extremely rare, IVSS should be considered in the differential diagnosis of primary intravascular neoplasms and as a potential cause of deep vein thrombosis and thromboembolism.

Double Right Bronchial Artery Aneurysm Treated with Combined Procedures

PURPOSE

Bronchial artery aneurysms occur rarely. We present an unusual case.

CASE REPORT

We present a patient with double right bronchial artery aneurysms that were treated with a combination of endovascular and surgical procedures.

CONCLUSION

This case report illustrates the treatment options for this unusual problem.