Extracellular vesicles in cancer: challenges and opportunities for clinical laboratories

Extracellular vesicles (EVs) are nano-sized particles secreted by most cells. They transport different types of biomolecules (nucleic acids, proteins, and lipids) characteristic of their tissue or cellular origin that can mediate long-distance intercellular communication. In the case of cancer, EVs participate in tumor progression by modifying the tumor microenvironment, favoring immune tolerance and metastasis development. Consequently, EVs have great potential in liquid biopsy for cancer diagnosis, prognosis and follow-up. In addition, EVs could have a role in cancer treatment as a targeted drug delivery system. The intense research in the EV field has resulted in hundreds of patents and the creation of biomedical companies. However, methodological issues and heterogeneity in EV composition have hampered the advancement of EV validation trials and the development of EV-based diagnostic and therapeutic products. Consequently, only a few EV biomarkers have moved from research to clinical laboratories, such as the ExoDx Prostate IntelliScore (EPI) test, a CLIA/FDA-approved EV prostate cancer diagnostic test. In addition, the number of large-scale multicenter studies that would clearly define biomarker performance is limited. In this review, we will critically describe the different types of EVs, the methods for their enrichment and characterization, and their biological role in cancer. Then, we will specially focus on the parameters to be considered for the translation of EV biology to the clinic laboratory, the advances already made in the field of EVs related to cancer diagnosis and treatment, and the issues still pending to be solved before EVs could be used as a routine tool in oncology.

Anomalous Magnetic Anisotropy Behaviour in Co-Rich and Fe-Rich Glass-Coated Microwires under Applied Stress

In this article, we study the effect of annealing temperature and applied stress on the magnetic properties of Fe71.80B13.27Si11.02Nb2.99Ni0.92 and Co65.34Si12.00B10.20Cr8.48Fe3.90Mo0.08 microwires. An anomalous behavior of the coercive field is observed while applying stress, indicating nontrivial changes in the microwire magnetic anisotropy. The effect of applied stimuli on the magnetic anisotropy and magnetostriction constant in both microwires is also discussed.

Clinical implications of changing thyroglobulin and antithyroglobulin antibodies analytical methods in the follow-up of patients with differentiated thyroid carcinoma

BACKGROUND AND AIMS

Patients' response to treatment in differentiated thyroid cancer (DTC) is classified according to serum thyroglobulin concentrations (Tg), usually using the American Thyroid Association guidelines and considering potential interfering anti-thyroglobulin antibodies (Ab-Tg). We aim to evaluate the clinical implications of changing Tg and Ab-Tg quantification method.

MATERIAL AND METHODS

Tg and Ab-Tg were quantified in 82 serum samples (60 from DTC patients) by Elecsys and Access immunoassays.

RESULTS

Elecsys immunoassay rendered higher values of Tg than Access: mean bias 5.03 ng/mL (95%CI:-14.14-24.21). In DTC patients, there was an almost perfect agreement for response classification (kappa index = 0.833). Discrepancies appeared in patients with undetermined response, with a more tendency to subclassification with Access. Ab-Tg showed a poor correlation (r = 0.5394). When Elecsys cut-off was reduced to 43 IU/mL, agreement for positive/negative classification improved from a kappa index of 0.607 to 0.650. Prospective study with personalized follow-up showed that only 6.3% of Tg results required an analytical confirmation, being confirmed 93% of them.

CONCLUSIONS

Despite the biases observed, clinical impact of an analytical change is minimal in patients' management. However, cautious and personalized follow-up period after the change is still mandatory, especially in patients with Tg levels between 0.2 and 1 ng/mL.

Analysis of common biomarkers in capillary blood in routine clinical laboratory. Preanalytical and analytical comparison with venous blood

OBJECTIVES

Remote self-collected capillary blood samples have been proposed as alternative to venous blood samples as an aid in telemedicine. The aim of this work is to compare the preanalytical and analytical performance of these two types of samples and to study the stability of common measurands in capillary blood.

METHODS

Capillary and venous blood samples were collected in parallel from 296 patients in serum tubes to analyze 22 common biochemistry magnitudes after centrifugation and in EDTA tubes to analyze 15 hematologic magnitudes. Quality of the preanalytical process was assessed applying the model of quality indicator. 24 h stability at room temperature was studied by obtaining paired capillary samples. A questionnaire of assessment was conducted.

RESULTS

Mean hemolysis index was higher in capillary samples compared to venous blood samples (p<0.001). Regression analysis and difference analysis showed no bias for all studied biochemistry parameters and hematologic parameters, except mean corpuscular volume (MCV), between capillary and venous blood samples. Regarding sample stability, percentage deviation was higher than the corresponding minimum analytical performance specification for ferritin, vitamin D, hematocrit, MCV, mean corpuscular hemoglobin concentration, platelets distribution wide, mean platelet volume and basophils. Finger pricking was perceived as less painful (p<0.05) than venipuncture in participants who undergo more than one blood test per year.

CONCLUSIONS

Capillary blood can be used as an alternative to venous blood for the studied parameters in automated common clinical analyzers. Cautious should be taken if samples are not analyzed within 24 h from the collection.

Cross-species transmission and PB2 mammalian adaptations of highly pathogenic avian influenza A/H5N1 viruses in Chile

H5N1 highly pathogenic avian influenza viruses (HPAIV) emerged in wild birds in Chile in December 2022 and spilled over into poultry, marine mammals, and one human. Between December 9, 2022 - March 14, 2023, a coordinated government/academic response detected HPAIV by real-time RT-PCR in 8.5% (412/4735) of samples from 23 avian and 3 mammal orders. Whole-genome sequences obtained from 77 birds and 8 marine mammals revealed that all Chilean H5N1 viruses belong to lineage 2.3.4.4b and cluster monophyletically with viruses from Peru, indicating a single introduction from North America into Peru/Chile. Mammalian adaptations were identified in the PB2 segment: D701N in two sea lions, one human, and one shorebird, and Q591K in the human and one sea lion. Minor variant analysis revealed that D701N was present in 52.9 - 70.9% of sequence reads, indicating the presence of both genotypes within hosts. Further surveillance of spillover events is warranted to assess the emergence and potential onward transmission of mammalian adapted H5N1 HPAIV in South America.

State of affairs and future challenges in laboratory medicine in Spain: an analysis of the Spanish Society of Laboratory Medicine (SEQCML)

Objectives

Laboratory Medicine is a crucial discipline that contributes to the diagnosis, management and monitoring of patients. This branch of medicine faces two major challenges: New technologies and increased demand. There is limited information available of the state of affairs in Laboratory Medicine in Spain. This study provides a picture of clinical laboratories and clinical laboratory professionals.

Methods

The Spanish Society of Laboratory Medicine distributed a questionnaire among the 250 most representative centers (the ones with the largest volume of determinations and training programs), of which 174 (69.6%) returned the questionnaire providing data for 2019.

Results

Laboratories were classified according to the number of determinations. In total, 37% identified themselves as small (<1 million determinations per year); 40% considered themselves medium-sized (1-5 million determinations per year) and 23% considered they were large laboratories (>5 million determinations). The level of specialization of laboratory physicians and laboratory performance were higher in large laboratories. Most requests (87%) and determinations (93%) corresponded to biochemistry and hematology. As many as 63% of physicians had an indefinite contract, and 23% were older than 60 years.

Conclusions

Laboratory medicine is a consolidated discipline that is gaining relevance in Spain. It adds value to the diagnosis, prognosis and follow-up of diseases, and to treatment response monitoring. The results of this study will help us address challenges such as the need for specialized training for laboratory professionals; the emergence of technological innovations; exploitation of Big Data; optimization of quality management systems and patient safety.

PSA reactivity in extracellular microvesicles to commercial immunoassays

AIMS

Characterization of PSA in extracellular microvesicles (EVs) and its reactivity to commercial methods.

MATERIALS AND METHODS

EVs derived from serum of 47 prostate cancer (PCa) patients, 27 benign prostatic hyperplasia (BPH) patients and 42 healthy controls were analyzed. EVs isolation and quantification of PSA immunoreactive to total (ev-T-PSA) or free (ev-F-PSA) PSA immunoassays, were performed using commercial assays. PSA in CD81+ or CD63+ EVs was determined directly in serum by an immunocapture-ELISA (IC-ELISA).

RESULTS

Ev-T-PSA immunoreactive to Elecsys assay was detected in all samples. Median T-PSA ev/srm ratio was 2.20% (Q1-Q3: 0.80-4.00%), although in some samples this ratio reached 59%. T-PSA ev/srm ratio was higher in those samples with serum T-PSA below 4 µg/L than in those exceeding that cut-off (p<0.001). T-PSA ev/srm ratio was lower in PCa patients compared to healthy controls and BPH patients (p<0.001). Elecsys immunoassays detected higher concentrations of ev-T-PSA and ev-F-PSA than Immulite (p<0.001). PSA was detected by IC-ELISA more intensely in CD81+ EVs than in CD63+ EVs, and ev-T-PSA correlated with PSA+CD63+ (p<0.001) but not with PSA+CD81+.

CONCLUSION

EVs-bound PSA is another form of circulating PSA whose measurement could be easily performed in clinical laboratories by automated immunoassays.

MAPK inhibitors dynamically affect melanoma release of immune NKG2D-ligands, as soluble protein and extracellular vesicle-associated

Metastatic melanoma presents, in many cases, oncogenic mutations in BRAF, a MAPK involved in proliferation of tumour cells. BRAF inhibitors, used as therapy in patients with these mutations, often lead to tumour resistance and, thus, the use of MEK inhibitors was introduced in clinics. BRAFi/MEKi, a combination that has modestly increased overall survival in patients, has been proven to differentially affect immune ligands, such as NKG2D-ligands, in drug-sensitive vs. drug-resistant cells. However, the fact that NKG2D-ligands can be released as soluble molecules or in extracellular vesicles represents an additional level of complexity that has not been explored. Here we demonstrate that inhibition of MAPK using MEKi, and the combination of BRAFi with MEKi in vitro, modulates NKG2D-ligands in BRAF-mutant and WT melanoma cells, together with other NK activating ligands. These observations reinforce a role of the immune system in the generation of resistance to directed therapies and support the potential benefit of MAPK inhibition in combination with immunotherapies. Both soluble and EV-associated NKG2D-ligands, generally decreased in BRAF-mutant melanoma cell supernatants after MAPKi in vitro, replicating cell surface expression. Because potential NKG2D-ligand fluctuation during MAPKi treatment could have different consequences for the immune response, a pilot study to measure NKG2D-ligand variation in plasma or serum from metastatic melanoma patients, at different time points during MAPKi treatment, was performed. Not all NKG2D-ligands were equally detected. Further, EV detection did not parallel soluble protein. Altogether, our data confirm the heterogeneity between melanoma lesions, and suggest testing several NKG2D-ligands and other melanoma antigens in serum, both as soluble or vesicle-released proteins, to help classifying immune competence of patients.

Effects of the COVID-19 pandemic on the activity of clinical laboratories in Spain, evolution in the 2019-2021 period

Objectives

To assess the impact of the COVID-19 pandemic on the activity of clinical laboratories in Spain.

Methods

A descriptive, observational, retrospective, multicenter study.

Results

Between March and December 2020, there was a statistically significant decrease in the number of test requests (-17.7%, p=<0.001) and total tests performed (-18.3%, p<0.001) with respect to the same period in 2019. A decrease was observed in the number of requests from primary care (-37.4%) (p<0.001) and in the number of foecal occult blood (-45.8%); qualitative urine (-30.1%); PSA (-28.5%); TSH (-27.8%); total cholesterol (-27.2%) and HbA_1c (-24.7%) tests performed, p<0.001. A significant increase was found in the number of requests from ICUs (76.6%, p<0.001) and number of IL-6 (+22,350.9), D-dimer (+617.2%), troponin (+46.8%) and arterial blood gas (+3.9%) tests carried out, p<0.001. During the first months of 2021, there were significant changes in the number of requests for qualitative urine (-8.7%, p<0.001), PSA (-6.3%, p=0.009), IL-6 (+66,269.2, p<0.001), D-dimer (+603.6%, p<0.001), troponin (+28.7%, p<0.001), arterial blood gas (+26,2%, p=0.014) and ferritin (+16.0%, p=0.002) tests performed.

Conclusions

There were changes in the origin and number of test requested to clinical laboratories in Spain. The number of requests for the evaluation and monitoring of COVID-19 patients increased, whereas requests for the control of non-COVID patients and for population screening decreased. Long-term analysis reveals that the volume of tests performed for the control of chronic diseases returned to normal over time, whereas the increase observed in the volume of tests performed for the management of COVID-19 patients is maintained.

Humoral and cellular immune response over 9 months of mRNA-1273, BNT162b2 and ChAdOx1 vaccination in a University Hospital in Spain

Scarce data have been reported about cellular immunity and longevity for different COVID-19 vaccination schedules. We carried out a prospective study enrolling 709 healthcare workers receiving two doses of mRNA-1273, BNT162b2, ChAdOx1, ChAdOx1/BNT162b2 or ChAdOx1 single dose to compare humoral and cellular immunogenicity across 9 months. Higher SARS-CoV-2 spike antibody levels were observed among individuals with hybrid immunity with one dose of any vaccine in comparison to uninfected individuals receiving two doses (mRNA-1273: 20,145 vs 4295 U/mL; BNT162b2: 15,659 vs 1959 U/mL; ChAdOx1: 5344 vs 2230 U/mL), except for ChAdOx1/BNT162b2 heterologous schedule (12,380 U/mL). Naturally infected individuals did not increase substantially the titers after the second dose and showed higher levels throughout the 9 months follow-up. The mean elimination half-life of antibodies among COVID-19 naïve participants was 98, 111, 60 and 36 days, for mRNA-1273, BNT162b2, ChAdOx1/ChAdOx1 and ChAdOx1/BNT162b2, respectively. Cellular immunity was preserved in 96%, 98%, 88% and 92% of uninfected individuals who received mRNA-1273, BNT162b2, ChAdOx1/ChAdOx1 and ChAdOx1/BNT162b2 after 6/9 months. Individuals with specific T cells showed robust long lasting protection, especially when m-RNA based vaccines are inoculated. These data may influence the validity of the vaccination passport and the need for booster vaccinations.

Modification of baseline status to improve breath tests performance

Breath tests used to evaluate carbohydrates malabsorption require baseline H₂ and CH₄ levels as low as possible. Test cancellation is recommended when exceeding certain cut-offs (H₂ ≥ 20 ppm and CH₄ ≥ 10 ppm). Although following preparation protocols, many patients have baseline levels above those cut-offs. We investigated if light walking can reduce baseline H₂ and CH₄ levels. We retrospectively analyzed baseline H₂ and CH₄ levels from 1552 breath tests. Baseline levels (B1), especially in H₂, were lower when obtained at later hours of the day. In those with baseline levels above cut-off, re-sampling (B2) after light walking for one hour, decreased H₂ levels 8 ppm (Q1–Q3: 1–18 ppm), and 2 ppm (Q1–Q3: 0–3 ppm) for CH₄. Consequently, 40% of tests with elevated B1 levels, presented B2 levels below mentioned cut-offs. Ten percent of tests considered negative when using B1 for calculations, turned positive when using B2 instead. All positive tests when using B1 values, remained elevated when using B2. Re-sampling after light walking for one hour could allow test performance in those with previous elevated baseline levels, avoiding diagnosis delays. Using the second sample for delta calculations identifies positive patients for malabsorption that would have been considered negative.

Impact of ultra-low temperature long-term storage on the preanalytical variability of twenty-one common biochemical analytes

OBJECTIVES

Retrospective studies frequently assume analytes long-term stability at ultra-low temperatures. However, these storage conditions, common among biobanks and research, may increase the preanalytical variability, adding a potential uncertainty to the measurements. This study is aimed to evaluate long-term storage stability of different analytes at <-70 °C and to assess its impact on the reference change value formula.

METHODS

Twenty-one analytes commonly measured in clinical laboratories were quantified in 60 serum samples. Samples were immediately aliquoted and frozen at <-70 °C, and reanalyzed after 11 ± 3.9 years of storage. A change in concentration after storage was considered relevant if the percent deviation from the baseline measurement was significant and higher than the analytical performance specifications.

RESULTS

Preanalytical variability (CV_P) due to storage, determined by the percentage deviation, showed a noticeable dispersion. Changes were relevant for alanine aminotransferase, creatinine, glucose, magnesium, potassium, sodium, total bilirubin and urate. No significant differences were found in aspartate aminotransferase, calcium, carcinoembryonic antigen, cholesterol, C-reactive protein, direct bilirubin, free thryroxine, gamma-glutamyltransferase, lactate dehydrogenase, prostate-specific antigen, triglycerides, thyrotropin, and urea. As nonnegligible, CV_P must remain included in reference change value formula, which was modified to consider whether one or two samples were frozen.

CONCLUSIONS

After long-term storage at ultra-low temperatures, there was a significant variation in some analytes that should be considered. We propose that reference change value formula should include the CV_P when analyzing samples stored in these conditions.

A simple immunoassay for extracellular vesicle liquid biopsy in microliters of non-processed plasma

BACKGROUND

Extracellular vesicles (EVs), released by most cell types, provide an excellent source of biomarkers in biological fluids. However, in order to perform validation studies and screenings of patient samples, it is still necessary to develop general techniques permitting rapid handling of small amounts of biological samples from large numbers of donors.

RESULTS

Here we describe a method that, using just a few microliters of patient's plasma, identifies tumour markers exposed on EVs. Studying physico-chemical properties of EVs in solution, we demonstrate that they behave as stable colloidal suspensions and therefore, in immunocapture assays, many of them are unable to interact with a stationary functionalised surface. Using flocculation methods, like those used to destabilize colloids, we demonstrate that cationic polymers increase EV ζ-potential, diameter, and sedimentation coefficient and thus, allow a more efficient capture on antibody-coated surfaces by both ELISA and bead-assisted flow cytometry. These findings led to optimization of a protocol in microtiter plates allowing effective immunocapture of EVs, directly in plasma without previous ultracentrifugation or other EV enrichment. The method, easily adaptable to any laboratory, has been validated using plasma from lung cancer patients in which the epithelial cell marker EpCAM has been detected on EVs.

CONCLUSIONS

This optimized high throughput, easy to automate, technology allows screening of large numbers of patients to phenotype tumour markers in circulating EVs, breaking barriers for the validation of proposed EV biomarkers and the discovery of new ones.

LC-MS-Based Metabolomics Discriminates Premium from Standard Chilean cv. Cabernet Sauvignon Wines from Different Valleys

Cabernet Sauvignon grapes in Chile, mainly grown between the 30° S and 36° S, account for more than 30% of Chilean wine production, and yield wines with different characteristics which influence their quality. The aim of this study was to apply a liquid chromatography – mass spectrometry (LC–MS)-based metabolomic protocol to investigate the quality differentiation in a sample set of monovarietal wines from eight valleys covering 679 km of the north-south extension. All samples were produced using a standardized red winemaking process and classified according to a company categorization in two major groups: premium and standard, and each group in two subcategories. The results pointed out that N-containing metabolites (mainly small peptides) are promising biomarkers for quality differentiation. Moreover, the premium wines were characterized by higher amounts of anthocyanins and other glycosylated and acetylated flavonoids, as well as phenolic acids; standard quality wines, on the other hand, presented stilbenoids and sulfonated catabolites of tryptophan and flavanols.

Performance comparison of two next-generation sequencing panels to detect actionable mutations in cell-free DNA in cancer patients

Background Genomic alterations studies in cell-free DNA (cfDNA) have increasing clinical use in oncology. Next-generation sequencing (NGS) technology provides the most complete mutational analysis, but nowadays limited data are available related to the comparison of results reported by different platforms. Here we compare two NGS panels for cfDNA: Oncomine™ Pan-Cancer Cell-Free Assay (Thermo Fisher Scientific), suitable for clinical laboratories, and Guardant360® (GuardantHealth), with more genes targeted but only available in an outsourcing laboratory. Methods Peripheral blood was obtained from 16 advanced cancer patients in which Guardant360® (G360) was requested as part of their clinical assistance. Blood samples were sent to be analyzed with G360 panel, and an additional blood sample was drawn to obtain and analyze cfDNA with Oncomine™ Pan-Cancer (OM) panel in an Ion GeneStudio S5™ System. Results cfDNA analysis globally rendered 101 mutations. Regarding the 55/101 mutations claimed to be included by manufacturers in both panels, 17 mutations were reported only by G360, 10 only by OM and 28 by both. In those coincident cases, there was a high correlation between the variant allele fractions (VAFs) calculated with each panel (r = 0.979, p < 0.01). Regarding the six actionable mutations with an FDA-approved therapy reported by G360, one was missed with OM. Also, 12 mutations with clinical trials available were reported by G360 but not by OM. Conclusions In summary, G360 and OM can produce different mutational profile in the same sample, even in genes included in both panels, which is especially important if these mutations are potentially druggable.

Characterization of the perioperative changes of exosomal immune-related cytokines induced by prostatectomy in early-stage prostate cancer patients

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) are relevant in prostate cancer microenvironment collaborating in tumor development. The main tumor marker used in this disease, prostate-specific antigen (PSA), does not provide information related to this tumor microenvironment. Cancer cells secrete exosomes carrying bioactive molecules contributing to MDSCs recruitment and induction. The aim of this study was to characterize the perioperative changes of exosomal cytokines relevant in MDSCs recruitment induced by prostatectomy in prostate cancer patients.

METHODS

Blood was drawn from 26 early-stage prostate cancer patients before and after radical prostatectomy and from 16 healthy volunteers. Serum exosomes were separated by precipitation. Cytokines related with MDSC cell recruitment and activation CCL2, CXCL2, CXCL5, CXCL8, CXCL12, MIF, S100A9 and TGF-ß were measured in serum and serum-derived exosomes using immunometric assays.

RESULTS

All cytokines were detected both in serum and exosomes, except for CXCL12, which was detected only in serum. Exosomes were enriched specially in MIF, TGF-ß and CXCL2. Presurgical MIF levels in exosomes correlated negatively with serum PSA. Also, presurgical TGF-ß decreased both in serum and exosomes as Gleason score rises. Patientś presurgical exosomes had increased CCL2, CXCL5 and TGF-ß levels than exosomes from healthy controls. These differences were not observed when cytokines were analyzed in serum, except for TGF-ß. Cytokine levels of CCL2, CXCL5 decreased in patients' postsurgical exosomes, while TGF-ß further increased. On the contrary, S100A9 levels were lower in patientś presurgical exosomes but increased after radical prostatectomy.

CONCLUSIONS

Blood exosomal content in cytokines constitute an attractive source to evaluate MDSCs immunomodulators providing additional information related to tumor microenvironment in prostate cancer.

Lactose tolerance test as an alternative to hydrogen breath test in the study of lactose malabsorption

Objectives

Lactose malabsorption is generally assessed by hydrogen breath testing (HBT). However, this test is not recommended in patients with high baseline hydrogen concentrations (H₂B). In addition, breath testing is not recommended in the current situation created by the COVID-19 pandemic, due to the potential infectiveness of the samples. The objective is to assess concordance between HBT and lactose tolerance test (LTT) depending on H₂B concentrations.

Methods

A total of 430 patients (40 years, Q1-Q3 = 28-54 years; 66.7% women) suspected of lactose malabsorption were included in the study. Breath and heparinized blood samples were collected at baseline and sequentially after the intake of 50 g of lactose, to measure hydrogen in breath and glycemia in blood, respectively.

Results

H₂B was <10 ppm in 69.5% of subjects; 10-20 ppm in 14.7%; and >20 ppm in 15.8% of subjects. In patients with H₂B <20 ppm, concordance between HBT and LTT was moderate and consistently improved when the cut-off in LTT was set at 15 mg/dL. The increase in hydrogen and glucose correlated negatively (r=-0.389; p<0.05). The increase in glycemia during LTT was not influenced by H₂B levels obtained in HBT.

Conclusions

LTT emerges as an alternative to HBT to assess lactose malabsorption in the presence of high H₂B levels or when breath testing is not recommended by the circumstances. The best concordance was obtained when the cut-off for LTT was set at 15 mg/dL.

Liver prometastatic reaction: Stimulating factors and responsive cancer phenotypes

Cancer is first a localized tissue disorder, whose soluble and exosomal molecules and invasive cells induce a host response providing the stromal components of the primary tumor microenvironment (TME). Once the TME is developed, cancer-derived molecules and cells can more efficiently spread out and a whole-body response takes place, whose pathophysiological changes may result in a paraneoplastic syndrome. Remote organ-specific prometastatic reactions may also occur at this time, facilitating metastatic activities of circulating tumor cells (CTCs) through premetastatic niche development at targeted organs. However, additional signaling factors from the inter-organ communication network involved in the pathophysiology and comorbidities of cancer patients may also regulate prometastatic reaction-stimulating effects of cancer and non-cancer tissue factors. This article provides a conceptual overview of our ongoing clinical research on the liver prometastatic reaction (LPR) of patients with colorectal cancer (CRC), their portal vein- and hepatic artery-driven LPR-Stimulating Factors (LPR-SF), and their resulting LPR-derived Metastasis-Stimulating Factors (LPR-MSF) acting on liver-invading CRC cells. In addition, we also provide new insights on the molecular subtyping of LPR-responsive cancer phenotypes in patients with CRC and melanoma; and on how to investigate and interpret the prometastatic infrastructure in the real pathophysiological context of patients with cancer undergoing surgical procedures and receiving pharmacological treatments with multiple side effects, including those affecting the LPR, its stimulating factors and responsive cancer phenotypes.

Utility of recombinant human TSH stimulation test in the follow-up of patients with differentiated thyroid cancer depending on basal thyroglobulin results

Background

Thyroglobulin (Tg) is fundamental for differentiated thyroid cancer (DTC) monitoring. Tg detection can be enhanced using recombinant human thyroid-stimulating hormone (TSH) (rhTSH). This study is aimed to evaluate the use of the rhTSH stimulation test when using a high-sensitivity Tg assay.

Methods

We retrospectively studied 181 rhTSH tests from 114 patients with DTC and negative for antithyroglobulin antibodies (anti-TgAb). Image studies were performed in all cases. Serum Tg and anti-TgAb were measured using specific immunoassays.

Results

rhTSH stimulation in patients with basal serum Tg (b-Tg) concentrations lower than 0.2 ng/mL always resulted in rhTSH-stimulated serum Tg (s-Tg) concentrations lower than 1.0 ng/mL and negative structural disease. In patients with b-Tg concentration between 0.2 and 1.0 ng/mL, s-Tg detected one patient (1/30) who showed biochemical incomplete response. Patients with negative images had lower s-Tg than those with nonspecific or abnormal findings (p<0.05). Receiver operating characteristic curve analysis of the s-Tg to detect altered images showed an area under the curve of 0.763 (p<0.05). With an s-Tg cutoff of 0.85 ng/mL, the sensitivity was 100%, decreasing to 96.15% with an s-Tg cutoff of 2 ng/mL.

Conclusions

Patients with DTC with b-Tg concentrations equal or higher than 0.2 ng/mL can benefit from the rhTSH stimulation test.

A profile on cobas® EGFR Mutation Test v2 as companion diagnostic for first-line treatment of patients with non-small cell lung cancer

INTRODUCTION

Among non-small cell lung cancer (NSCLC) patients, there is one molecularly defined subgroup harboring activating mutations in the epidermal growth factor receptor gene (EGFR), which results in constitutive activation of its intrinsic kinase activity. Consistent data have demonstrated that these patients have a better outcome when treated with specific tyrosine-kinase inhibitors (EGFR-TKIs). Therefore, analysis of EGFR mutational status for treatment guidance is mandatory in this context.

AREAS COVERED

Herein we review the clinical development and technical features of cobas® EGFR Mutation Test v2 as a companion diagnostic test (CDx) for therapy with EGFR-TKIs, such as gefitinib, in advanced NSCLC. We also discuss the pros and cons of the current version of the CDx and its performance in both tissue and plasma samples.

EXPERT OPINION

The RT-PCR based cobas® EGFR Mutation Test v2 is a reliable and rapid solution for EGFR mutational status assessment at the time of diagnosis in advanced NSCLC that allows eligibility of patients for EGFR-TKI treatment. This test determines EGFR mutations with acceptable sensitivity in tissue or plasma samples. Pre-analytical considerations like tumor cell content, tumor burden or location of metastasis should be considered to better interpret results in the clinical contexture.

Universality of power-law exponents by means of maximum-likelihood estimation

Power-law-type distributions are extensively found when studying the behavior of many complex systems. However, due to limitations in data acquisition, empirical datasets often only cover a narrow range of observation, making it difficult to establish power-law behavior unambiguously. In this work we present a statistical procedure to merge different datasets, with two different aims. First, we obtain a broader fitting range for the statistics of different experiments or observations of the same system. Second, we establish whether two or more different systems may belong to the same universality class. By means of maximum likelihood estimation, this methodology provides rigorous statistical information to discern whether power-law exponents characterizing different datasets can be considered equal among them or not. This procedure is applied to the Gutenberg-Richter law for earthquakes and for synthetic earthquakes (acoustic emission events) generated in the laboratory: labquakes. Different earthquake catalogs have been merged finding a Gutenberg-Richter law holding for more than eight orders of magnitude in seismic moment. The value of the exponent of the energy distribution of labquakes depends on the material used in the compression experiments. By means of the procedure proposed in this manuscript, we find that the Gutenberg-Richter law for earthquakes and charcoal labquakes can be characterized by the same power-law exponent, whereas Vycor labquakes exhibit a significantly different exponent.

External Validation of 3 Risk Scores in Adults with Congenital Heart Disease

Background and Objectives

Adults with congenital heart disease (CHD) are an increasing group of patients thanks to the survival of over 85% of children with CHD. 20% of these patients shall warrant a surgical procedure during their life span. However, currently there is no one risk score that assess correctly the mortality of these procedures. Thus, we analyse the risk scores used at our institution.

Methods

From May 1991 till June 2017, 608 procedures in adults with CHD were performed. The 3 risk scores (risk adjustment for congenital heart surgery [RACHS-1], Aristotle, and Euroscore I) of each procedure were analysed. We used area under the receiver operating characteristic curve (c-index) to measure model discrimination, and Hosmer-Lemeshow (H-L) statistic along with calibration plots to measure calibration.

Results

There was no statistical difference between the area under the curve for the 3 scores (χ²=0.58 with 2 df, p=0.750). There was no evidence of lack of fit for RACHS-1 (H-L, χ²=2.61; p=0.271) and Aristotle score (H-L, χ²=5.69; p=0.459). However, there was evidence in lack of calibration in the Euroscore I scoring system (H-L, χ²=33.69; p<0.001). The calibration slope for RACHS-1 was 0.912, for Aristotle (stratified in risk groups) was −0.14 and for Euroscore 1 (stratified in risk groups) was 0.46.

Conclusions

RACHS-1 seems to be best risk scoring system for calculating mortality applied to surgery in adults with CHD.

Comparison of six commercial serum exosome isolation methods suitable for clinical laboratories. Effect in cytokine analysis

Background

Exosomes are nanovesicles released by cells that can be detected in blood. Exosomes contain several molecules, such as cytokines that have potential utility as disease biomarkers. The aim of the present work is to compare six different commercial kits suitable for the clinical laboratory in relation to the efficiency and purity of exosome isolation, and their effect in subsequent cytokines analysis.

Methods

Serum exosomes were obtained from 10 volunteers using six commercial kits: exoEasy, ExoQuick, Exo-spin, ME kit, ExoQuick Plus and Exo-Flow. Exosome concentrations and size distributions were quantified by nanoparticle tracking analysis. Exosome markers CD63, CD9 and TSG101 were determined by Western blot. ApoB and albumin were measured using nephelometry. S100A9, CXCL5 and CXCL12 were measured using a Luminex assay.

Results

The concentration of particles obtained between different kits varied by a factor of 100. There was no correlation in particle concentrations extracted between different kits, except between ExoQuick and Exo-Flow. The highest exosome purity was achieved with ExoQuick Plus and exoEasy, while the lowest were achieved with ME and ExoQuick. Albumin was present in all exosome extracts analyzed and ApoB in all except those extracted with Exo-Flow and ME. Cytokine detection varied depending on the purification kit used and there was no correlation in cytokine concentrations between samples obtained with different kits.

Conclusions

Both the sample and the type of commercial kit used affect the efficiency and purity of exosome isolation. In addition, the exosome purification method deeply affects the capability to detect and quantify cytokines.

Evaluation of an active yeast propagation system on fermentation traits and quality of C.V. Carmenère wine

Active dry yeasts (ADY, Saccharomyces cerevisiae) are widely used in oenology due to their potential benefits on the control of fermentation and quality reproducibility among other aspects. On the other hand, yeast propagation systems, so called Active Yeast Systems (AYS), can be useful to optimize the alcoholic fermentation (AF) initial lag phase and reduce production costs. The objective of this work was to determine the predominance of an ADY strain propagated by AYS and the impact of this inoculum on cv. Carmenère wine quality. Lalvin ICV D21 ADY strain was inoculate according to the protocol recommended by the manufacturer (T0), and in parallel, it was propagate by the AYS and then used as inoculum (T1). Yeast strain predominance analyzed by restriction fragment length polymorphism (RFLP) technique indicates that nine (out of 9) yeast colonies obtained from a single sample of the ADY, show the same electrophoretic pattern when compared to the ADY. The results show limited significant differences for the fermentation speed and the yeast cell counting. The result of the physicochemical analysis of the musts and resulting wines showed no significant differences between treatments. A triangular test showed no significant sensory differences between wines

Long-term photosynthetic CO2 removal from biogas and flue-gas: Exploring the potential of closed photobioreactors for high-value biomass production

The long-term performance of a tubular photobioreactor interconnected to a gas absorption column for the abatement of CO₂ from biogas and flue-gas was investigated. Additionally, a novel nitrogen feast-famine regime was implemented during the flue-gas feeding stage in order to promote the continuous storage of highly-energetic compounds. Results showed effective CO₂ (~98%) and H₂S (~99%) removals from synthetic biogas, supported by the high photosynthetic activity of microalgae which resulted in an alkaline pH (~10). In addition, CO₂ removals of 99 and 91% were observed during the flue-gas operation depending on the nutrients source: mineral salt medium and digestate, respectively. A biomass productivity of ~8 g m^-2 d^-1 was obtained during both stages, with a complete nitrogen and carbon recovery from the cultivation broth. Moreover, the strategy of feeding nutrients during the dark period promoted the continuous accumulation of carbohydrates, their concentration increasing from 22% under normal nutrition up to 37% during the feast-famine cycle. This represents a productivity of ~3 g-_{carbohydrates} m^-2 d^-1, which can be further valorized to contribute to the economic sustainability of the photosynthetic CO₂ removal process.

Depletion of S100A4+ stromal cells does not prevent HCC development but reduces the stem cell-like phenotype of the tumors

There is a pressing need for the development of novel approaches to treat and prevent hepatocellular carcinoma (HCC). The S100 calcium-binding protein S100A4 is associated with poor prognosis and metastasis in several human cancers. In addition, a role for S100A4 in modulating cancer-initiating cells stemness properties was recently proposed in head and neck and gastric cancers. Whether S100A4⁺ stromal cells contribute to tumor onset remains, however, an unanswered question. To address that question, we generated a new mouse model allowing for the depletion of S100A4⁺ cells in a mouse model of HCC with stemness properties, by crossing mice with hepatic deletion of phosphatase and tensin homolog (PTEN) with mice expressing viral thymidine kinase under the control of S100A4 promoter. Depletion of S100A4⁺ cells by ganciclovir injection did not prevent the development of HCC but reduced the stemness phenotype of the tumor as measured by the expression of progenitor cell, biliary cell and hepatocyte markers. The results were further confirmed by histology analysis showing reduction of cholangiolar tumor components and degree of oval cell hyperplasia in the adjacent liver. Depletion of S100A4⁺ cells had also some beneficial effect on the underlying liver disease with a reduction of NAS score, largely due to the reduction of inflammation. In conclusion, this study demonstrated that S100A4⁺ cells do not contribute to HCC onset but maintain the stemness phenotype of the tumor. This study also suggests for the first time a crosstalk between inflammation and stemness.

Asynchronous Telepsychiatry: A Component of Stepped Integrated Care

OBJECTIVE

Integrated behavioral healthcare models typically involve a range of consultation options for mental healthcare. Asynchronous telepsychiatry (ATP) consults may be an additional potential choice, so we are conducting a 5-year clinical trial comparing ATP with synchronous telepsychiatry (STP) consultations.

METHODS

Patients referred by primary care providers are randomly assigned to one of the two treatment groups, ATP or STP. Clinical outcome, satisfaction, and economic data are being collected from patients for 2 years at 6-month intervals.

RESULTS

Baseline characteristics for the first 158 patients and case examples of ATP are presented.

CONCLUSION

Implementing ATP in existing integrated behavioral healthcare models could make mental healthcare more efficient.

Interleukin-8 in cancer pathogenesis, treatment and follow-up

Interleukin-8 (CXCL8) was originally described asa chemokine whose main function is the attraction of a polymorphonuclear inflammatory leukocyte infiltrate acting on CXCR1/2. Recently, it has been found that tumors very frequently coopt the production of this chemokine, which in this malignant context exerts different pro-tumoral functions. Reportedly, these include angiogenesis, survival signaling for cancer stem cells and attraction of myeloid cells endowed with the ability to immunosuppress and locally provide growth factors. Given the fact that in cancer patients IL-8 is mainly produced by tumor cells themselves, its serum concentration has been shown to correlate with tumor burden. Thus, IL-8 serum concentrations have been shown to be useful asa pharmacodynamic biomarker to early detect response to immunotherapy. Finally, because of the roles that IL-8 plays in favoring tumor progression, several therapeutic strategies are being developed to interfere with its functions. Such interventions hold promise, especially for therapeutic combinations in the field of cancer immunotherapy.

Opposite Effects of Mechanical Action of Fluid Flow on Proangiogenic Factor Secretion From Human Adipose-Derived Stem Cells With and Without Oxidative Stress

Mechanical forces, hypoxia, and oxidative stress contribute to skin renewal, perfusion, and wound healing, but how are they regulating subcutaneous adipose-derived stem cells (ASCs) in the inflammatory microenvironment associated to skin repair and disorders is unknown. In this study, ASCs were isolated from lipoaspirate samples from plastic surgery patients, primary cultured and their differentiation and secretion of a panel of cytokines with pronounced effects on skin repair and angiogenesis were studied under mechanical stimulation by intermittent fluid flow, 1% hypoxia and oxidative stress by glutathione (GSH) depletion with buthionine sulfoximine (BSO) treatment. Mechanical action of fluid flow did not alter mesenchymal phenotype of CD90⁺ /CD29⁺ /CD44⁺ /CD34^- /CD106^- /CD45^- ASCs; however, it remarkably induced ASC secretion of human umbilical vein endothelial cell (HUVEC) migration-stimulating factors. Multiplex Luminex assay further confirmed an increased secretion of VEGF, G-CSF, HGF, Leptin, IL-8, PDGF-BB, Angiopoietin-2, and Follistatin from mechanically-stimulated ASCs via cyclooxygenase-2. Consistent with this mechanism, GSH depletion and hypoxia also increased ASC secretion of VEGF, IL-8, leptin, Angiopoitein-2, and PDGF-BB. However, mechanical action of fluid flow abrogated VEGF and HUVEC migration-stimulating activity from GSH-depleted and hypoxic ASCs. Conversely, GSH depletion and hypoxia abrogated VEGF and HUVEC migration-stimulating activity from mechano-stimulated ASCs. Although mechanical action of fluid flow, hypoxia, and GSH-depletion had independent proangiogenic-stimulating activity on ASCs, mechanical stimulation had opposite effects on proangiogenic factor secretion from ASCs with and without oxidative stress. These data uncover the role of hypoxia and endogenous redox balance during the proangiogenic response of ASCs and other mesenchymal-derived cell types to mechanical action of interstitial fluid flow. J. Cell. Physiol. 232: 2158-2167, 2017. © 2016 Wiley Periodicals, Inc.

Neonatal and pediatric extracorporeal membrane oxygenation in developing Latin American countries

OBJECTIVE

To review the principles of neonatal-pediatric extracorporeal membrane oxygenation therapy, prognosis, and its establishment in limited resource-limited countries in Latino America.

SOURCES

The PubMed database was explored from 1985 up to the present, selecting from highly-indexed and leading Latin American journals, and Extracorporeal Life Support Organization reports.

SUMMARY OF THE FINDINGS

Extracorporeal membrane oxygenation provides "time" for pulmonary and cardiac rest and for recovery. It is used in the neonatal-pediatric field as a rescue therapy for more than 1300 patients with respiratory failure and around 1000 patients with cardiac diseases per year. The best results in short- and long-term survival are among patients with isolated respiratory diseases, currently established as a standard therapy in referral centers for high-risk patients. The first neonatal/pediatric extracorporeal membrane oxygenation Program in Latin America was established in Chile in 2003, which was also the first program in Latin America to affiliate with the Extracorporeal Life Support Organization. New extracorporeal membrane oxygenation programs have been developed in recent years in referral centers in Argentina, Colombia, Brazil, Mexico, Perú, Costa Rica, and Chile, which are currently funding the Latin American Extracorporeal Life Support Organization chapter.

CONCLUSIONS

The best results in short- and long-term survival are in patients with isolated respiratory diseases. Today extracorporeal membrane oxygenation therapy is a standard therapy in some Latin American referral centers. It is hoped that these new extracorporeal membrane oxygenation centers will have a positive impact on the survival of newborns and children with respiratory or cardiac failure, and that they will be available for an increasing number of patients from this region in the near future.

Distinct Osteomimetic Response of Androgen-Dependent and Independent Human Prostate Cancer Cells to Mechanical Action of Fluid Flow: Prometastatic Implications

BACKGROUND AND METHODS

Prostate cancer frequently expresses an osteomimetic phenotype, but it is unclear how it is regulated and what biological and clinical implications it confers. Because mechanical forces physiologically regulate bone-remodeling activity in osteocytes, we hypothesized that mechanical action of fluid flow (MAFF) at the cancer microenvironment may similarly foster prostate cancer cell osteomimicry.

RESULTS

We showed that in vitro MAFF on androgen-dependent (LNCap) and androgen-independent (PC3) prostate cancer cells remarkably increased OPG, VEGF, RunX2, PTH1R, and PTHrP gene expression in both cell lines irrespective of their androgen dependency. MAFF also altered the cytokine secretion pattern of prostate cancer cells, including Ang2, SCF, and TNFα increase with TRAIL decrease in the supernatant of both cell lines; preferential increase of Leptin and PDGF-BB in LnCap and of VEGF, IL-8, and G-CSF in PC3; and exclusive increase of FGFβ, MIF, and PECAM-1 with HGF decrease in LnCap, and of TGBβ1, HGF, M-CSF, CXCL1, and CCL7 with NGF decrease in PC3. Murine MLO-Y4 osteocyte-conditioned medium (CM) abrogated M-CSF, G-CSG, IL-8, TNFα, and FGFβ secretion-stimulating activity of mechanical stimulation on PC3 cells, and did the opposite effect on LnCap cells. However, MAFF fostered osteomimetic gene expression response of PC3 cells, but not of LnCap cells, to mechanically stimulated osteocyte-CM. Moreover, it abrogated TNFα and IL-8 secretion inhibitory effect of osteocyte-CM on mechanically stimulated PC3 cells and G-CSF, TNFα, and FGFβ-stimulating effect on mechanically stimulated LnCap cells.

CONCLUSIONS

MAFF activated osteoblast-like phenotype of prostate cancer cells and altered their responses to osteocyte soluble factors. It also induced osteocyte production of osteomimetic gene expression- and cytokine secretion-stimulating factors for prostate cancer cells, particularly, when they were mechanically stimulated. Importantly, MAFF induced a prometastatic response in androgen-independent prostate cancer cells, suggesting the interest of mechanical stimulation-dependent transcription and secretion patterns as diagnostic biomarkers, and as therapeutic targets for the screening of bone-metastasizing phenotype inhibitors upregulated during prostate cancer cell response to MAFF at the cancer microenvironment. Prostate 77:321-333, 2017. © 2016 Wiley Periodicals, Inc.

Circulating biomarkers in malignant melanoma

Melanoma is an aggressive tumor with increasing incidence worldwide. Biomarkers are valuable tools to minimize the cost and improve efficacy of treatment of this deadly disease. Serological markers have not widely been introduced in routine clinical practice due to their insufficient diagnostic sensitivity and specificity. It is likely that the lack of objective responses with traditional treatment hinder biomarker research and development in melanoma. Recently, new drugs and therapies have, however, emerged in advanced melanoma with noticeable objective response ratio and survival. In this new scenario, serological tumor markers should be revisited. In addition, other potential circulating biomarkers such as cell-free DNA, exosomes, microRNA, and circulating tumor cells have also been identified. In this review, we summarize classical and emerging tumor markers and discuss their possible roles in emerging therapeutics.

New insights into the structural requirements for pro-apoptotic agents based on 2,4-diaminoquinazoline, 2,4-diaminopyrido[2,3-d]pyrimidine and 2,4-diaminopyrimidine derivatives

As a continuation of our work on new anti-tumoral derivatives with selective pro-apoptotic activity in cancer cells, we describe the synthesis and the preliminary evaluation of the cytotoxic and pro-apoptotic activities of a series of pyrimidin-2,4-diamine derivatives that are structurally related to quinazolin-2,4-diamine and pyrido[2,3-d]pyrimidin-2,4-diamine derivatives. We also describe the structure-activity relationship studies carried out on four series' of quinazolin-2,4-diamine, 2-(alkylsulfanyl)-N-alkyl- and 2-(alkylsulfanyl)-N-alkylarylpyrido[2,3-d]pyrimidine and pyrimidin-2,4-diamine derivatives. The proposed preliminary pharmacophore consists of a flat heterocyclic ring, preferably a pyrido[2,3-d]pyrimidine, with two equivalent alkylarylamine chains, preferably N-benzyl- or N-ethylphenylamine, located in positions 2 and 4 of the ring, and with a preferred ALogP in the range 4.5-5.5. The nitrogen present in the central ring can act as hydrogen bond acceptors (HBA) whereas the amino group in the 4-position can act as a donor (HBD) or an HBA and the amino group in the 2-position can act as an HBD. On the basis of the analyzed structural profiles, different mechanisms of action can be suggested for the quinazolin-2,4-diamine, the 2-(alkylsulfanyl)-N-alkylpyrido[2,3-d]pyrimidin-4-amine and the pyrido[2,3-d]pyrimidin-2,4-diamine derivatives.