Venopulmonary Artery Extracorporeal Life Support (VPa ECMO): A Novel Strategy for Refractory Hypoxemia Complicating VV ECMO.

Refractory hypoxemia (RH) during venovenous extracorporeal membrane oxygenation (VV ECMO) support is a complex problem that limits the benefit of this therapy. The need for sustained deep sedation and delays in active rehabilitation are considered as a direct consequence of RH. Changing from VV ECMO to a configuration that returns the flow to pulmonary artery, such as venopulmonary extracorporeal membrane oxygenation (VPa ECMO) may decrease recirculation and improve systemic oxygen delivery. We present a retrospective report that describes the impact of VPa ECMO on oxygenation during sedation withdrawal in 41 patients who received VV ECMO for coronavirus disease 2019 (COVID-19). We evidenced that arterial oxygen pressure (PaO 2 ) increased from 68 to 112.3 mm Hg ( p = 0.001) with a reduction of ECMO flow (5.7-4.8 L/m; p = 0.001). Other findings included lower rates of depth sedation (Richmond Agitation Sedation Scale [RASS] ≤3, 37-63%; p = 0.007) and lower requirement inotropic support assessed by LVIS score (4.7-1.1; p = 0.005). Discharge survival was 54% with a sustained benefit until day 79. This cannulation strategy improved effectively PaO 2 in this cohort, it may be an alternative in patients with RH in VV ECMO.

Mercury maternal transfer in two placental sharks and a yolk-sac ray from Baja California Sur, Mexico.

Total mercury (THg) concentrations were measured in muscle and liver of two placental viviparous sharks, the Pacific sharpnose shark (Rhizoprionodon longurio) and the brown smooth-hound (Mustelus henlei); as well as in the muscle, liver, and yolk of the yolk-sac viviparous speckled guitarfish (Pseudobatos glaucostigmus) in Baja California Sur. The aim was to determine which factors could be involved in maternal transfer and resultant maternal and embryonic THg concentration. Higher THg concentrations were found in pregnant females compared to embryos paired tissues. THg concentrations of embryo tissues decreased with total length (TL), except for the muscle of the Pacific sharpnose shark. THg concentrations of embryo muscle was positively related to THg concentration in the muscle of pregnant females. Embryos TL, muscle THg concentration of pregnant females, percentage of THg concentration in embryos, along with the reproductive strategy are relevant factors required to improve our understanding of THg concentration in embryo tissues.

Multimodal Interaction between a Mother and Her Twin Preterm Infants (Male and Female) in Maternal Speech and Humming during Kangaroo Care: A Microanalytical Case Study.

The literature reports the benefits of multimodal interaction with the maternal voice for preterm dyads in kangaroo care. Little is known about multimodal interaction and vocal modulation between preterm mother-twin dyads. This study aims to deepen the knowledge about multimodal interaction (maternal touch, mother's and infants' vocalizations and infants' gaze) between a mother and her twin preterm infants (twin 1 [female] and twin 2 [male]) during speech and humming in kangaroo care. A microanalytical case study was carried out using ELAN, PRAAT, and MAXQDA software (Version R20.4.0). Descriptive and comparative analysis was performed using SPSS software (Version V27). We observed: (1) significantly longer humming phrases to twin 2 than to twin 1 (p = 0.002), (2) significantly longer instances of maternal touch in humming than in speech to twin 1 (p = 0.000), (3) a significant increase in the pitch of maternal speech after twin 2 gazed (p = 0.002), and (4) a significant increase of pitch in humming after twin 1 vocalized (p = 0.026). This exploratory study contributes to questioning the role of maternal touch during humming in kangaroo care, as well as the mediating role of the infant's gender and visual and vocal behavior in the tonal change of humming or speech.

Comprehensive Plasma Metabolomic Profile of Patients with Advanced Neuroendocrine Tumors (NETs). Diagnostic and Biological Relevance.

PURPOSE: High-throughput "-omic" technologies have enabled the detailed analysis of metabolic networks in several cancers, but NETs have not been explored to date. We aim to assess the metabolomic profile of NET patients to understand metabolic deregulation in these tumors and identify novel biomarkers with clinical potential. METHODS: Plasma samples from 77 NETs and 68 controls were profiled by GC-MS, CE-MS and LC-MS untargeted metabolomics. OPLS-DA was performed to evaluate metabolomic differences. Related pathways were explored using Metaboanalyst 4.0. Finally, ROC and OPLS-DA analyses were performed to select metabolites with biomarker potential. RESULTS: We identified 155 differential compounds between NETs and controls. We have detected an increase of bile acids, sugars, oxidized lipids and oxidized products from arachidonic acid and a decrease of carnitine levels in NETs. MPA/MSEA identified 32 enriched metabolic pathways in NETs related with the TCA cycle and amino acid metabolism. Finally, OPLS-DA and ROC analysis revealed 48 metabolites with diagnostic potential. CONCLUSIONS: This study provides, for the first time, a comprehensive metabolic profile of NET patients and identifies a distinctive metabolic signature in plasma of potential clinical use. A reduced set of metabolites of high diagnostic accuracy has been identified. Additionally, new enriched metabolic pathways annotated may open innovative avenues of clinical research.

Foraging depth depicts resource partitioning and contamination level in a pelagic shark assemblage: Insights from mercury stable isotopes.

The decline of shark populations in the world ocean is affecting ecosystem structure and function in an unpredictable way and new ecological information is today needed to better understand the role of sharks in their habitats. In particular, the characterization of foraging patterns is crucial to understand and foresee the evolution of dynamics between sharks and their prey. Many shark species use the mesopelagic area as a major foraging ground but the degree to which different pelagic sharks rely on this habitat remains overlooked. In order to depict the vertical dimension of their trophic ecology, we used mercury stable isotopes in the muscle of three pelagic shark species (the blue shark Prionace glauca, the shortfin mako shark Isurus oxyrinchus and the smooth hammerhead shark Sphyrna zygaena) from the northeastern Pacific region. The Δ199Hg values, ranging from 1.40 to 2.13‰ in sharks, suggested a diet mostly based on mesopelagic prey in oceanic habitats. We additionally used carbon and nitrogen stable isotopes (δ13C, δ15N) alone or in combination with Δ199Hg values, to assess resource partitioning between the three shark species. Adding Δ199Hg resulted in a decrease in trophic overlap estimates compared to those based on δ13C/δ15N alone, demonstrating that multi-isotope modeling is needed for accurate trophic description of the three species. Mainly, it reveals that they forage at different average depths and that resource partitioning is mostly expressed through the vertical dimension within pelagic shark assemblages. Concomitantly, muscle total mercury concentration (THg) differed between species and increased with feeding depth. Overall, this study highlights the key role of the mesopelagic zone for shark species foraging among important depth gradients and reports new ecological information on trophic competition using mercury isotopes. It also suggests that foraging depth may play a pivotal role in the differences between muscle THg from co-occurring high trophic level shark species.

High Throughput Profiling of Flavonoid Abundance in Agave lechuguilla Residue-Valorizing under Explored Mexican Plant.

Agave lechuguilla waste biomass (guishe) is an undervalued abundant plant material with natural active compounds such as flavonoids. Hence, the search and conservation of flavonoids through the different productive areas have to be studied to promote the use of this agro-residue for industrial purposes. In this work, we compared the proportion of total flavonoid content (TFC) among the total polyphenolics (TPC) and described the variation of specific flavonoid profiles (HPLC-UV-MS/MS) of guishe from three locations. Descriptive environmental analysis, using remote sensing, was used to understand the phytochemical variability among the productive regions. Furthermore, the effect of extractive solvent (ethanol and methanol) and storage conditions on specific flavonoid recovery were evaluated. The highest TPC (16.46 ± 1.09 GAE/g) was observed in the guishe from region 1, which also had a lower normalized difference water index (NDWI) and lower normalized difference vegetation index (NDVI). In contrast, the TFC was similar in the agro-residue from the three studied areas, suggesting that TFC is not affected by the studied environmental features. The highest TFC was found in the ethanolic extracts (6.32 ± 1.66 QE/g) compared to the methanolic extracts (3.81 ± 1.14 QE/g). Additionally, the highest diversity in flavonoids was found in the ethanolic extract of guishe from region 3, which presented an intermedia NDWI and a lower NDVI. Despite the geo-climatic induced variations of the phytochemical profiles, the results confirm that guishe is a valuable raw material in terms of its flavonoid-enriched bioactive extracts. Additionally, the bioactive flavonoids remain stable when the conditioned agro-residue was hermetically stored at room temperature in the dark for nine months. Finally, the results enabled the establishment of both agro-ecological and biotechnological implications.

Isotopic (δ15 N) relationship of pregnant females and their embryos: Comparing placental and yolk-sac viviparous elasmobranchs.

Nitrogen stable isotopes ratios (δ15 N) were determined for selected tissues (muscle, liver, blood and yolk) of pregnant females and their embryos of a placental viviparous species, the Pacific sharpnose shark (Rhizoprionodon longurio), and a yolk-sac viviparous species, the speckled guitarfish (Pseudobatos glaucostigmus). The R. longurio embryo tissues were 15 N enriched compared to the same tissues in the pregnant female, using the difference in δ15 N (Δδ15 N) between embryo and adult. Mean Δδ15 N was 2.17‰ in muscle, 4.39‰ in liver and 0.80‰ in blood. For P. glaucostigmus, embryo liver tissue was significantly 15 N enriched in comparison with liver of the pregnant female (Δδ15 N mean = 1.22‰), whereas embryo muscle was 15 N depleted relative to the muscle of the pregnant female (Δδ15 N mean = -1.22‰). Both species presented a significant positive linear relationship between Δδ15 N and embryo total length (LT ). The results indicated that embryos have different Δδ15 N depending on their reproductive strategy, tissue type analysed and embryo LT .

UNR/CSDE1 Expression Is Critical to Maintain Invasive Phenotype of Colorectal Cancer through Regulation of c-MYC and Epithelial-to-Mesenchymal Transition.

CSDE1 (cold shock domain containing E1) gene is located upstream of the N-RAS locus, and codes for an RNA-binding protein named Upstream of N-Ras (UNR). In cancer, CSDE1 has been shown to regulate c-Fos, c-Myc, Pten, Rac1, or Vimentin. UNR/CSDE1 has been studied in breast, melanoma, pancreatic and prostate cancer. Then, the aim of this study is to evaluate the role of CSDE1/UNR in colorectal cancer progression and maintenance of aggressive phenotype. We firstly evaluated UNR/CSDE1 expression in human colon cancer derived cell lines and patient samples. Subsequently, we performed functional experiments by UNR/CSDE1 downregulation. We also evaluated UNR/CSDE1 prognostic relevance in two independent sets of patients. Not only was UNR/CSDE1 expression higher in tumor samples compared to untransformed samples, but also in colonospheres and metastatic origin cell lines than their parental and primary cell lines, respectively. Downregulation of UNR/CSDE1 reduced cell viability and migration throughout a restrain of epithelial-to-mesenchymal transition and increases sensitivity to apoptosis. Interestingly, high UNR/CSDE1 expression was associated with poor prognosis and correlated positively with c-MYC expression in colorectal cancer samples and cell lines. Here, we show for the first time compelling data reporting the oncogenic role of UNR/CSDE1 in human colorectal cancer.

Predictive performance of regression models to estimate Chlorophyll-a concentration based on Landsat imagery.

Chlorophyll-a (Chl-a) concentration is a key parameter to describe water quality in marine and freshwater environments. Nowadays, several products with Chl-a have derived from satellite imagery, but they are not available or reliable sometimes for coastal and/or small water bodies. Thus, in the last decade several methods have been described to estimate Chl-a with high-resolution (30 m) satellite imagery, such as Landsat, but a standardized method to estimate Chl-a from Landsat imagery has not been accepted yet. Therefore, this study evaluated the predictive performance of regression models (Simple Linear Regression [SLR], Multiple Linear Regression [MLR] and Generalized Additive Models [GAMs]) to estimate Chl-a based on Landsat imagery, using in situ Chl-a data collected (synchronized with the overpass of Landsat 8 satellite) and spectral reflectance in the visible light portion (bands 1-4) and near infrared (band 5). These bands were selected because of Chl-a absorbance/reflectance properties in these wavelengths. According to goodness of fit, GAM outperformed SLR and MLR. However, the model validation showed that MLR performed better in predicting log-transformed Chl-a. Thus, MLR, constructed by using four spectral bands (1, 2, 3, and 5), was considered the best method to predict Chl-a. The coefficients of this model suggested that log-transformed Chl-a concentration had a positive linear relationship with bands 1 (coastal/aerosol), 3 (green), and 5 (NIR). On the other hand, band 2 (blue) suggested a negative relationship, which implied high coherence with Chl-a absorbance/reflectance properties measured in the laboratory, indicating that Landsat 8 images could be applied effectively to estimate Chl-a concentrations in coastal environments.

Effect of Congruence Between Sound and Video on Heart Rate and Self-Reported Measures of Emotion.

Most studies of emotional responses have used unimodal stimuli (e.g., pictures or sounds) or congruent bimodal stimuli (e.g., video clips with sound), but little is known about the emotional response to incongruent bimodal stimuli. The aim of the present study was to evaluate the effect of congruence between auditory and visual bimodal stimuli on heart rate and self-reported measures of emotional dimension, valence and arousal. Subjects listened to pleasant, neutral, and unpleasant sounds, accompanied by videos with and without content congruence, and heart rate was recorded. Dimensions of valence and arousal of each bimodal stimulus were then self-reported. The results showed that heart rate depends of the valence of the sounds but not of the congruence of the bimodal stimuli. The valence and arousal scores changed depending on the congruence of the bimodal stimuli. These results suggest that the congruence of bimodal stimuli affects the subjective perception of emotion.

A comprehensive study of calcific aortic stenosis: from rabbit to human samples.

The global incidence of calcific aortic stenosis (CAS) is increasing owing, in part, to a growing elderly population. The condition poses a great challenge to public health, because of the multiple comorbidities of these older patients. Using a rabbit model of CAS, we sought to characterize protein alterations associated with calcified valve tissue that can be ultimately measured in plasma as non-invasive biomarkers of CAS. Aortic valves from healthy and mild stenotic rabbits were analyzed by two-dimensional difference gel electrophoresis, and selected reaction monitoring was used to directly measure the differentially expressed proteins in plasma from the same rabbits to corroborate their potential as diagnostic indicators. Similar analyses were performed in plasma from human subjects, to examine the suitability of these diagnostic indicators for transfer to the clinical setting. Eight proteins were found to be differentially expressed in CAS tissue, but only three were also altered in plasma samples from rabbits and humans: transitional endoplasmic reticulum ATPase, tropomyosin α-1 chain and L-lactate dehydrogenase B chain. Results of receiver operating characteristic curves showed the discriminative power of the scores, which increased when the three proteins were analyzed as a panel. Our study shows that a molecular panel comprising three proteins related to osteoblastic differentiation could have utility as a serum CAS indicator and/or therapeutic target.

Potential role of new molecular plasma signatures on cardiovascular risk stratification in asymptomatic individuals.

The evaluation of cardiovascular (CV) risk is based on equations derived from epidemiological data in individuals beyond the limits of middle age such as the Framingham and SCORE risk assessments. Lifetime Risk calculator (QRisk®), estimates CV risk throughout a subjects' lifetime, allowing those. A more aggressive and earlier intervention to be identified and offered protection from the consequences of CV and renal disease. The search for molecular profiles in young people that allow a correct stratification of CV risk would be of great interest to adopt preventive therapeutic measures in individuals at high CV risk. To improve the selection of subjects susceptible to intervention with aged between 30-50 years, we have employed a multiple proteomic strategy to search for new markers of early CV disease or reported CV events and to evaluate their relationship with Lifetime Risk. Blood samples from 71 patients were classified into 3 groups according to their CV risk (healthy, with CV risk factors and with a previously reported CV event subjects) and they were analyzed using a high through quantitative proteomics approach. This strategy allowed three different proteomic signatures to be defined, two of which were related to CV stratification and the third one involved markers of organ damage.

Recent advances and clinical insights into the use of proteomics in the study of atherosclerosis.

INTRODUCTION: The application of new proteomics methods may help to identify new diagnostic/predictive molecular markers in an attempt to improve the clinical management of atherosclerosis. Areas covered: Technological advances in proteomics have enhanced its sensitivity and multiplexing capacity, as well as the possibility of studying protein interactions and tissue structure. These advances will help us better understand the molecular mechanisms at play in atherosclerosis as a biological system. Moreover, this should help identify new predictive/diagnostic biomarkers and therapeutic targets that may facilitate effective risk stratification and early diagnosis, with the ensuing rapid implementation of treatment. This review provides a comprehensive overview of the novel methods in proteomics, including state-of-the-art techniques, novel biological samples and applications for the study of atherosclerosis. Expert commentary: Collaboration between clinicians and researchers is crucial to further validate and introduce new molecular markers to manage atherosclerosis that are identified using the most up to date proteomic approaches.

Modeling the flux of metabolites in the juvenile hormone biosynthesis pathway using generalized additive models and ordinary differential equations.

Juvenile hormone (JH) regulates development and reproductive maturation in insects. The corpora allata (CA) from female adult mosquitoes synthesize fluctuating levels of JH, which have been linked to the ovarian development and are influenced by nutritional signals. The rate of JH biosynthesis is controlled by the rate of flux of isoprenoids in the pathway, which is the outcome of a complex interplay of changes in precursor pools and enzyme levels. A comprehensive study of the changes in enzymatic activities and precursor pool sizes have been previously reported for the mosquito Aedes aegypti JH biosynthesis pathway. In the present studies, we used two different quantitative approaches to describe and predict how changes in the individual metabolic reactions in the pathway affect JH synthesis. First, we constructed generalized additive models (GAMs) that described the association between changes in specific metabolite concentrations with changes in enzymatic activities and substrate concentrations. Changes in substrate concentrations explained 50% or more of the model deviances in 7 of the 13 metabolic steps analyzed. Addition of information on enzymatic activities almost always improved the fitness of GAMs built solely based on substrate concentrations. GAMs were validated using experimental data that were not included when the model was built. In addition, a system of ordinary differential equations (ODE) was developed to describe the instantaneous changes in metabolites as a function of the levels of enzymatic catalytic activities. The results demonstrated the ability of the models to predict changes in the flux of metabolites in the JH pathway, and can be used in the future to design and validate experimental manipulations of JH synthesis.

Downregulation of microRNA-199b predicts unfavorable prognosis and emerges as a novel therapeutic target which contributes to PP2A inhibition in metastatic colorectal cancer.

The tumor suppressor microRNA-199b (miR-199b) is a negative SET regulator associated with poor outcome in some human cancers. However, its expression levels as well as potential biological and clinical significance in colorectal cancer (CRC) remain completely unexplored. The PP2A inhibitor SET has shown promising therapeutic and clinical implications in metastatic CRC (mCRC) but the molecular mechanisms underlying SET deregulation are currently unknown. We show here miR-199b downregulation in 4 out of 5 CRC SET-overexpressing cell lines and its inverse correlation with SET overexpression in CRC patients. Moreover, miR-199b led to PP2A activation through a direct SET inhibition, impaired cell viability and enhanced oxaliplatin sensitivity in CRC cells. MiR-199b was found downregulated in 25% of cases, and associated with lymph metastasis (p = 0.049), presence of synchronous metastasis at diagnosis (p = 0.026) and SET overexpression (p < 0.001). Furthermore, low miR-199b levels determined shorter overall (p < 0.001), progression-free survival (p = 0.003) and predicted clinical benefit to oxaliplatin treatment. The miR-199b prognostic impact was particularly evident in both younger and KRAS wild-type subgroups. Multivariate analyses confirmed its independent prognostic impact. Altogether, our results show that miR-199b is a tumor suppressor whose downregulation independently determines worse outcome and emerges as a potential contributing mechanism to inhibit PP2A via SET overexpression in a subgroup of mCRC patients.

c-Jun N-Terminal Kinase Inactivation by Mitogen-Activated Protein Kinase Phosphatase 1 Determines Resistance to Taxanes and Anthracyclines in Breast Cancer.

MAPK phosphatase-1 (MKP-1) is overexpressed during malignant transformation of the breast in many patients, and it is usually associated with chemoresistance through interference with JNK-driven apoptotic pathways. Although the molecular settings of the mechanism have been documented, details about the contribution of MKP-1 to the failure of chemotherapeutic interventions are unclear. Transient overexpression of MKP-1 and treatment with JNK-modulating agents in breast carcinoma cells confirmed the mediation of MKP-1 in the resistance to taxanes and anthracyclines in breast cancer, through the inactivation of JNK1/2. We next assessed MKP-1 expression and JNK1/2 phosphorylation status in a large cohort of samples from 350 early breast cancer patients treated with adjuvant anthracycline-based chemotherapy. We detected that MKP-1 overexpression is a recurrent event predominantly linked to dephosphorylation of JNK1/2 with an adverse impact on relapse of the tumor and overall and disease-free survival. Moreover, MKP-1 and p-JNK1/2 determinations in 64 locally advanced breast cancer patients treated with neoadjuvant taxane-based chemotherapy showed an inverse correlation between MKP-1 overexpression (together with JNK1/2 inhibition) and the pathologic response of the tumors. Our results emphasize the importance of MKP-1 as a potential predictive biomarker for a subset of breast cancer patients with worse outcome and less susceptibility to treatment. Mol Cancer Ther; 15(11); 2780-90. ©2016 AACR.

Pyrosequencing-Based Assays for Rapid Detection of HER2 and HER3 Mutations in Clinical Samples Uncover an E332E Mutation Affecting HER3 in Retroperitoneal Leiomyosarcoma.

Mutations in Human Epidermal Growth Factor Receptors (HER) are associated with poor prognosis of several types of solid tumors. Although HER-mutation detection methods are currently available, such as Next-Generation Sequencing (NGS), alternative pyrosequencing allow the rapid characterization of specific mutations. We developed specific PCR-based pyrosequencing assays for identification of most prevalent HER2 and HER3 mutations, including S310F/Y, R678Q, L755M/P/S/W, V777A/L/M, 774-776 insertion, and V842I mutations in HER2, as well as M91I, V104M/L, D297N/V/Y, and E332E/K mutations in HER3. We tested 85 Formalin Fixed and Paraffin Embbeded (FFPE) samples and we detected three HER2-V842I mutations in colorectal carcinoma (CRC), ovarian carcinoma, and pancreatic carcinoma patients, respectively, and a HER2-L755M mutation in a CRC specimen. We also determined the presence of a HER3-E332K mutation in an urothelial carcinoma sample, and two HER3-D297Y mutations, in both gastric adenocarcinoma and CRC specimens. The D297Y mutation was previously detected in breast and gastric tumors, but not in CRC. Moreover, we found a not-previously-described HER3-E332E synonymous mutation in a retroperitoneal leiomyosarcoma patient. The pyrosequencing assays presented here allow the detection and characterization of specific HER2 and HER3 mutations. These pyrosequencing assays might be implemented in routine diagnosis for molecular characterization of HER2/HER3 receptors as an alternative to complex NGS approaches.

Nuclear DICKKOPF-1 as a biomarker of chemoresistance and poor clinical outcome in colorectal cancer.

Sporadic colorectal cancer (CRC) insurgence and progression depend on the activation of Wnt/ß-catenin signaling. Dickkopf (DKK)-1 is an extracellular inhibitor of Wnt/ß-catenin signaling that also has undefined ß-catenin-independent actions. Here we report for the first time that a proportion of DKK-1 locates within the nucleus of healthy small intestine and colon mucosa, and of CRC cells at specific chromatin sites of active transcription. Moreover, we show that DKK-1 regulates several cancer-related genes including the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) and Ral-binding protein 1-associated Eps domain-containing 2 (REPS2), which are involved in detoxification of chemotherapeutic agents. Nuclear DKK-1 expression is lost along CRC progression; however, it remains high in a subset (15%) of CRC patients (n = 699) and associates with decreased progression-free survival (PFS) after chemotherapy administration and overall survival (OS) [adjusted HR, 1.65; 95% confidence interval (CI), 1.23-2.21; P = 0.002)]. Overexpression of ALDH1A1 and REPS2 associates with nuclear DKK-1 expression in tumors and correlates with decreased OS (P = 0.001 and 0.014) and PFS. In summary, our findings demonstrate a novel location of DKK-1 within the cell nucleus and support a role of nuclear DKK-1 as a predictive biomarker of chemoresistance in colorectal cancer.

PP2A inhibition determines poor outcome and doxorubicin resistance in early breast cancer and its activation shows promising therapeutic effects.

The protein phosphatase 2A (PP2A) is a key tumor suppressor which has emerged as a novel molecular target in some human cancers. Here, we show that PP2A inhibition is a common event in breast cancer and identified PP2A phosphorylation and deregulation SET and CIP2A as molecular contributing mechanisms to inactivate PP2A. Interestingly, restoration of PP2A activity after FTY720 treatment reduced cell growth, induced apoptosis and decreased AKT and ERK activation. Moreover, FTY720 led to PP2A activation then enhancing doxorubicin-induced antitumor effects both in vitro and in vivo. PP2A inhibition (CPscore: PP2A phosphorylation and/or CIP2A overexpression) was detected in 27% of cases (62/230), and associated with grade (p = 0.017), relapse (p < 0.001), negative estrogen (p < 0.001) and progesterone receptor expression (p < 0.001), HER2-positive tumors (p = 0.049), Ki-67 expression (p < 0.001), and higher AKT (p < 0.001) and ERK (p < 0.001) phosphorylation. Moreover, PP2A inhibition determined shorter overall (p = 0.006) and event-free survival (p = 0.003), and multivariate analysis confirmed its independent prognostic impact. Altogether, our results indicate that PP2A is frequently inactivated in breast cancer and determines worse outcome, and its restoration using PP2A activators represents an alternative therapeutic strategy in this disease.

Deregulation of the PP2A inhibitor SET shows promising therapeutic implications and determines poor clinical outcome in patients with metastatic colorectal cancer.

PURPOSE: SET is an endogenous PP2A inhibitor that might represent a novel molecular target for antitumor therapy. The aim of this study was to evaluate the molecular effects of SET deregulation and its potential clinical significance in metastatic colorectal cancer (mCRC). EXPERIMENTAL DESIGN: We studied the biologic effects of SET on cell growth, colonosphere formation, caspase activity, PP2A activation status, and sensitivity to oxaliplatin and FTY720 treatments. Moreover, we analyzed SET expression by immunostaining in 242 patients with mCRC. RESULTS: SET deregulation promotes cell growth and colonosphere formation and inhibits PP2A, thereby impairing its antitumor effects. Moreover, SET reduces sensitivity to oxaliplatin in colorectal cancer cell lines, which is restored after FTY720 treatment. SET overexpression was detected in 24.8% (60 of 242) of patients with mCRC and determined significantly shorter overall (8.6 vs. 27 months; P < 0.001) and progression-free survival (7.1 vs. 13.7 months; P < 0.001), and poor response to oxaliplatin-based chemotherapy (P = 0.004). Interestingly, its prognostic value was particularly evident in patients younger than 70 years and in those harboring KRAS mutations. CONCLUSIONS: SET overexpression is a frequent event in mCRC that plays a potential oncogenic role associated with worse outcome and resistance to oxaliplatin. Moreover, this alteration defines a subgroup of patients who could benefit from therapies containing PP2A activators such as FTY720.