Glucose Metabolic Reprogramming of ER Breast Cancer in Acquired Resistance to the CDK4/6 Inhibitor Palbociclib

The majority of breast cancers express the estrogen receptor (ER) and are dependent on estrogen for their growth and survival. Endocrine therapy (ET) is the standard of care for these tumors. However, a superior outcome is achieved in a subset of ER positive (ER+)/human epidermal growth factor receptor 2 negative (HER2−) metastatic breast cancer patients when ET is administrated in combination with a cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor, such as palbociclib. Moreover, CDK4/6 inhibitors are currently being tested in ER+/HER2+ breast cancer and reported encouraging results. Despite the clinical advances of a combinatorial therapy using ET plus CDK4/6 inhibitors, potential limitations (i.e., resistance) could emerge and the metabolic adaptations underlying such resistance warrant further elucidation. Here we investigate the glucose-dependent catabolism in a series of isogenic ER+ breast cancer cell lines sensitive to palbociclib and in their derivatives with acquired resistance to the drug. Importantly, ER+/HER2− and ER+/HER2+ cell lines show a different degree of glucose dependency. While ER+/HER2− breast cancer cells are characterized by enhanced aerobic glycolysis at the time of palbociclib sensitivity, ER+/HER2+ cells enhance their glycolytic catabolism at resistance. This metabolic phenotype was shown to have prognostic value and was targeted with multiple approaches offering a series of potential scenarios that could be of clinical relevance

Optimisation Study of Co Deposition on Chars from MAP of Waste Tyres as Green Electrodes in ORR for Alkaline Fuel Cells

Oxygen Reduction Reaction (ORR) catalysts, from waste automobile tyres obtained from Microwave assisted pyrolysis (MAP), were enriched with Co and Cu using the simple treatments sonochemical and electrochemical deposition. Catalytic activity was evaluated through onset potential and number of exchanged electrons measurements. Electrochemical data demonstrate an improvement in catalytic activity of the electrochemical modified char with Co. Char electrodes enriched with Co show a maximum positive shift of 40 mV with respect to raw char electrodes with a number of exchanged electrons per O2 molecule close to 4 (as for Pt) for the best sample. This corresponds to a reduction of the production of unwanted oxygen peroxide from 23% for raw char to 1%. Sample structure evolution before and after electrochemical deposition and electro-catalysis was investigated by scanning transmission electron microscopy and XPS. Such electrochemical treatments open new possibilities of refining waste chars and finding an economic alternative to noble metals-based catalysts for alkaline fuel cells

L'attivita della timidina chinasi 1 come possibile marcatore precoce di risposta alla terapia endocrina nel tumore della mammella metastatico con recettori ormonali positivi

I tumori della mammella metastatici con recettori ormonali positivi sono generalmente trattati con terapia endocrina. Attualmente non esistono biomarcatori che permettano di individuare le pazienti che trarranno maggiore beneficio dalla sola terapia ormonale piuttosto che dalla combinazione con farmaci target che agiscono su pathway coinvolte nella resistenza alla terapia endocrina. Ipotizziamo che la valutazione dell’attività dell’enzima timidina chinasi 1 (TK1), riconosciuto marcatore di proliferazione cellulare, possa predire la risposta alla terapia ormonale. È stata valutata l’attività di TK1 in 3 linee cellulari luminali di tumore della mammella ( MCF7, T47D, ZR751) e nel plasma di 31 pazienti trattate con una prima, seconda o terza linea di terapia endocrina per malattia metastatica. I campioni ematici sono stati raccolti prima dell’inizio della terapia (T0), dopo 4 settimane di terapia (T1) e alla diagnosi di progressione di malattia (T2). Le linee cellulari la cui proliferazione è inibita dal trattamento con terapia endocrina (MCF7 e T47D) mostrano una riduzione significativa dell’attività di TK1. Le pazienti con bassi livelli basali di TK1 hanno una sopravvivenza libera da malattia (PFS) significativamente più lunga rispetto a quelle con alti livelli (25,9 mesi vs 5,85 mesi; p-value=0,012). Inoltre, le pazienti in cui l’attività di TK1 si riduce dal T0 al T1 hanno un beneficio significativo in termini di PFS (14,5 mesi vs 3,7 mesi; p-value=0,0026). Questi risultati supportano l’ipotesi che TK1 possa essere considerato un possibile marcatore precoce di risposta alla terapia endocrina nel tumore della mammella metastatico. Ulteriori studi confirmatori sono necessari

Magnetic Field Effect on the Handedness of Electrodeposited Heusler Alloy

Magneto-electrochemistry (MEC) experiments were carried out in the electrodeposition of a ferromagnetic Heusler alloy. The electrodeposition was carried out in the absence (as a reference) and in the presence of a magnetic field that was applied perpendicularly to the electrode–solution interface. The obtained metallic deposit was characterized by SEM-EDS, XRF, and XRD techniques. The ferromagnetic properties are assessed on the basis of SQUID measurements. The experimental results indicate that the influence of the presence of the magnetic field induces differences in the electrochemical measurements and a macroscopic handedness (chirality) in the deposit, which is a function of magnet orientation. Eventually, the coercivity of the Heusler alloy that was obtained in the presence of the magnetic field was larger compared to that of the deposit that was obtained without a magnetic field

ddSeeker: a tool for processing Bio-Rad ddSEQ single cell RNA-seq data

Abstract Background New single-cell isolation technologies are facilitating studies on the transcriptomics of individual cells. Bio-Rad ddSEQ is a droplet-based microfluidic system that, when coupled with downstream Illumina library preparation and sequencing, enables the monitoring of thousands of genes per cell. Sequenced reads show unique features that do not permit the use of freely available tools to perform single cell demultiplexing. Results We present ddSeeker, a tool to perform initial processing and quality metrics of reads generated through Bio-Rad ddSEQ/Illumina experiments. Its application to the Illumina test dataset demonstrates that ddSeeker performs better than Illumina BaseSpace software, enabling a higher recovery of valid reads. We also show its utility in the analysis of an in-house dataset including two read sets characterized by low and high sequencing quality. ddSeeker and its source code are available at https://github.com/cgplab/ddSeeker. Conclusions ddSeeker is a freely available tool to perform initial processing and quality metrics of reads generated through Bio-Rad ddSEQ/Illumina single cell transcriptomic experiments

A gene expression signature of Retinoblastoma loss-of-function predicts resistance to neoadjuvant chemotherapy in ER-positive/HER2-positive breast cancer patients

HER2-positive (HER2+) breast cancers show heterogeneous response to chemotherapy, with the ER-positive (ER+) subgroup deriving less benefit. Loss of retinoblastoma tumor suppressor gene (RB1) function has been suggested as a cardinal feature of breast cancers that are more sensitive to chemotherapy and conversely resistant to CDK4/6 inhibitors. We performed a retrospective analysis exploring RBsig, a gene signature of RB loss, as a potential predictive marker of response to neoadjuvant chemotherapy in ER+/HER2+ breast cancer patients.We selected clinical trials of neoadjuvant chemotherapy +/- anti-HER2 therapy in HER2+ breast cancer patients with available information on gene expression data, hormone receptor status, and pathological complete response (pCR) rates. RBsig expression was computed in silico and correlated with pCR.Ten studies fulfilled the inclusion criteria and were included in the analysis (514 patients). Overall, of 211 ER+/HER2+ breast cancer patients, 49 achieved pCR (23%). The pCR rate following chemotherapy +/- anti-HER2 drugs in patients with RBsig low expression was significantly lower compared to patients with RBsig high expression (16% vs. 30%, respectively; Fisher's exact test p = 0.015). The area under the ROC curve (AUC) was 0.62 (p = 0.005). In the 303 ER-negative (ER-)/HER2+ patients treated with chemotherapy +/- anti-HER2 drugs, the pCR rate was 43%. No correlation was found between RBsig expression and pCR rate in this group.Low expression of RBsig identifies a subset of ER+/HER2+ patients with low pCR rates following neoadjuvant chemotherapy +/- anti-HER2 therapy. These patients may potentially be spared chemotherapy in favor of anti-HER2, endocrine therapy, and CDK 4/6 inhibitor combinations

Cyclin E1 and Rb modulation as common events at time of resistance to palbociclib in hormone receptor-positive breast cancer

CDK4/6 inhibitors represent a new treatment standard for hormone receptor-positive (HR+), HER2-negative advanced breast cancer (BC) patients. Although efficacious, resistance to these agents is universal. Here, we profiled a large panel of HR+ BC cell lines with conditioned resistance to the CDK4/6 inhibitor palbociclib, and analyzed cell cycle-related markers by gene expression profiles (GEP) and western blot (WB). GEP showed high molecular heterogeneity among the models, with E2F targets being significantly enriched both during treatment and at the time of resistance. By both WB and GEP, a common molecular feature at the time of palbociclib resistance was the concomitant overexpression of cyclin E1 and down-regulation of Rb. CCNE1 was the only significantly up-regulated gene among E2F targets at resistance with CCNE1 genomic amplification being observed in two resistant models. Rb was downregulated in all resistant models; a reduction of RB1 copy number was observed in three resistant cell lines. In silico analyses showed that CCNE1/RB1 ratio correlated with palbociclib IC50 in different datasets of both breast and non-breast cancer cell lines, performing better than CCNE1 or RB1 taken separately. Finally, the CCNE1/RB1 ratio was shown to be an adverse prognostic factor in patients with ER+ BC and to be able to discriminate palbociclib-sensitive versus resistant among patients enrolled in the NeoPalAna trial, a neoadjuvant trial testing palbociclib, performing better than CCNE1 or RB1 alone. Our data suggest that the CCNE1/RB1 ratio may be a viable biomarker of palbociclib resistance, warranting further clinical validation

An RB-1 loss of function gene signature as a tool to predict response to neoadjuvant chemotherapy plus anti-HER2 agents: a substudy of the NeoALTTO trial (BIG 1-06)

Background: Chemotherapy added to anti-HER2 agents (H) is the treatment of choice in patients with HER2+ early breast cancer. However, HER2+ tumours are clinically and biologically heterogeneous, and treatment response varies significantly by hormone receptor (HR) status and molecular subtype. Predictive biomarkers are needed in this context. This study assessed whether an RB-1 loss of function gene signature (RBsig) is predictive of response to neoadjuvant chemotherapy in combination with trastuzumab, lapatinib or both, within the NeoALTTO trial. Methods: We collected RNA-sequencing data from pretreatment biopsies derived from the NeoALTTO trial. RBsig expression was computed retrospectively and correlated with pathological complete response (pCR) using receiver-operating characteristic (ROC) curves. The RBsig was dichotomised as High/Low in correspondence to the 25th percentile. Reported p values resulted from Fisher’s exact test. Results: Of 455 NeoALTTO patients, 244 were eligible for this substudy (HR+ n = 129; HR− n = 115). Overall, pCR rate was significantly higher in patients with RBsig High tumours than those with RBsig Low (35% versus 18% respectively; p = 0.01). The area under the ROC curve (AUC) was 0.60 (95% CI 0.52–0.67). A remarkably low pCR rate of 11% was seen in HR+/RBsig Low patients versus 28% in HR+/RBsig High. Conclusions: These results indicate RBsig may add valuable information to HER2 and HR expression, which may in turn inform treatment choices. HR+/HER2+/RBsig Low breast cancers exhibited the poorest pathological response following chemotherapy plus H. Accordingly, in such patients, endocrine therapy in combination with H and, possibly, a CDK4/6 inhibitor, may potentially prove to be a more effective treatment.SCOPUS: ar.jinfo:eu-repo/semantics/publishe