A Pilot Analysis of Whole Transcriptome of Human Cryopreserved Sperm

Sperm cryopreservation is a procedure widely used to store gametes for later use, to preserve fertility in patients prior to gonadotoxic treatments or surgery, and for sperm donation programs. The purpose of the study was to assess the impact of cryopreservation on human sperm transcriptome. Semen samples were collected from 13 normospermic men. Each sample was divided into two aliquots. The total RNA was immediately extracted from one aliquot. The second aliquot was frozen and total RNA was extracted after a week of storage in liquid nitrogen. The RNA samples were randomized in four pools, each of six donors, and analyzed by microarrays. The paired Significance Analysis of Microarray was performed. We found 219 lower abundant transcripts and 28 higher abundant transcripts in cryopreserved sperm than fresh sperm. The gene ontology analysis disclosed that cryopreservation alters transcripts of pathways important for fertility (i.e., spermatogenesis, sperm motility, mitochondria function, fertilization, calcium homeostasis, cell differentiation, and early embryo development), although the increase of some transcripts involved in immune response can compensate for the harmful effects of freezing.

Machine Learning Methods for Gene Selection in Uveal Melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy with a limited five-year survival for metastatic patients. Limited therapeutic treatments are currently available for metastatic disease, even if the genomics of this tumor has been deeply studied using next-generation sequencing (NGS) and functional experiments. The profound knowledge of the molecular features that characterize this tumor has not led to the development of efficacious therapies, and the survival of metastatic patients has not changed for decades. Several bioinformatics methods have been applied to mine NGS tumor data in order to unveil tumor biology and detect possible molecular targets for new therapies. Each application can be single domain based while others are more focused on data integration from multiple genomics domains (as gene expression and methylation data). Examples of single domain approaches include differentially expressed gene (DEG) analysis on gene expression data with statistical methods such as SAM (significance analysis of microarray) or gene prioritization with complex algorithms such as deep learning. Data fusion or integration methods merge multiple domains of information to define new clusters of patients or to detect relevant genes, according to multiple NGS data. In this work, we compare different strategies to detect relevant genes for metastatic disease prediction in the TCGA uveal melanoma (UVM) dataset. Detected targets are validated with multi-gene score analysis on a larger UM microarray dataset.

Clonal Extinction Drives Tumorigenesis

Before a tumor is diagnosed and surgically removed, it has been growing for many months or even years [...].

Genes selection using deep learning and explainable artificial intelligence for chronic lymphocytic leukemia predicting the need and time to therapy

Analyzing gene expression profiles (GEP) through artificial intelligence provides meaningful insight into cancer disease. This study introduces DeepSHAP Autoencoder Filter for Genes Selection (DSAF-GS), a novel deep learning and explainable artificial intelligence-based approach for feature selection in genomics-scale data. DSAF-GS exploits the autoencoder's reconstruction capabilities without changing the original feature space, enhancing the interpretation of the results. Explainable artificial intelligence is then used to select the informative genes for chronic lymphocytic leukemia prognosis of 217 cases from a GEP database comprising roughly 20,000 genes. The model for prognosis prediction achieved an accuracy of 86.4%, a sensitivity of 85.0%, and a specificity of 87.5%. According to the proposed approach, predictions were strongly influenced by CEACAM19 and PIGP, moderately influenced by MKL1 and GNE, and poorly influenced by other genes. The 10 most influential genes were selected for further analysis. Among them, FADD, FIBP, FIBP, GNE, IGF1R, MKL1, PIGP, and SLC39A6 were identified in the Reactome pathway database as involved in signal transduction, transcription, protein metabolism, immune system, cell cycle, and apoptosis. Moreover, according to the network model of the 3D protein-protein interaction (PPI) explored using the NetworkAnalyst tool, FADD, FIBP, IGF1R, QTRT1, GNE, SLC39A6, and MKL1 appear coupled into a complex network. Finally, all 10 selected genes showed a predictive power on time to first treatment (TTFT) in univariate analyses on a basic prognostic model including IGHV mutational status, del(11q) and del(17p), NOTCH1 mutations, β2-microglobulin, Rai stage, and B-lymphocytosis known to predict TTFT in CLL. However, only IGF1R [hazard ratio (HR) 1.41, 95% CI 1.08-1.84, P=0.013), COL28A1 (HR 0.32, 95% CI 0.10-0.97, P=0.045), and QTRT1 (HR 7.73, 95% CI 2.48-24.04, P<0.001) genes were significantly associated with TTFT in multivariable analyses when combined with the prognostic factors of the basic model, ultimately increasing the Harrell's c-index and the explained variation to 78.6% (versus 76.5% of the basic prognostic model) and 52.6% (versus 42.2% of the basic prognostic model), respectively. Also, the goodness of model fit was enhanced (χ2 = 20.1, P=0.002), indicating its improved performance above the basic prognostic model. In conclusion, DSAF-GS identified a group of significant genes for CLL prognosis, suggesting future directions for bio-molecular research.

Guadecitabine increases response to combined anti-CTLA-4 and anti-PD-1 treatment in mouse melanoma in vivo by controlling T-cells, myeloid derived suppressor and NK cells

BACKGROUND

The combination of Programmed Cell Death 1 (PD-1) and Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) blockade has dramatically improved the overall survival rate for malignant melanoma. Immune checkpoint blockers (ICBs) limit the tumor's immune escape yet only for approximately a third of all tumors and, in most cases, for a limited amount of time. Several approaches to overcome resistance to ICBs are being investigated among which the addition of epigenetic drugs that are expected to act on both immune and tumor cells. Guadecitabine, a dinucleotide prodrug of a decitabine linked via phosphodiester bond to a guanosine, showed promising results in the phase-1 clinical trial, NIBIT-M4 (NCT02608437).

METHODS

We used the syngeneic B16F10 murine melanoma model to study the effects of immune checkpoint blocking antibodies against CTLA-4 and PD-1 in combination, with and without the addition of Guadecitabine. We comprehensively characterized the tumor's and the host's responses under different treatments by flow cytometry, multiplex immunofluorescence and methylation analysis.

RESULTS

In combination with ICBs, Guadecitabine significantly reduced subcutaneous tumor growth as well as metastases formation compared to ICBs and Guadecitabine treatment. In particular, Guadecitabine greatly enhanced the efficacy of combined ICBs by increasing effector memory CD8+ T cells, inducing effector NK cells in the spleen and reducing tumor infiltrating regulatory T cells and myeloid derived suppressor cells (MDSC), in the tumor microenvironment (TME). Guadecitabine in association with ICBs increased serum levels of IFN-γ and IFN-γ-induced chemokines with anti-angiogenic activity. Guadecitabine led to a general DNA-demethylation, in particular of sites of intermediate methylation levels.

CONCLUSIONS

These results indicate Guadecitabine as a promising epigenetic drug to be added to ICBs therapy.

Spontaneous NLRP3 inflammasome-driven IL1-β secretion is induced in severe COVID-19 patients and responds to anakinra treatment

BACKGROUND

SARS-CoV-2 infection may result in a severe pneumonia associated to elevation of blood inflammatory parameters, reminiscent of cytokine storm syndrome. Steroidal anti-inflammatory therapies have shown efficacy in reducing mortality in critically ill patients, however the mechanisms by which SARS-CoV2 virus triggers such an extensive inflammation remain unexplained.

OBJECTIVES

To dissect the mechanisms underlying SARS-CoV-2 associated inflammation in severe COVID-19 patients we studied the role of IL-1β, a pivotal cytokine driving inflammatory phenotypes, whose maturation and secretion are regulated by inflammasomes.

METHODS

We analyzed NLRP3 pathway activation by means of confocal microscopy, plasma cytokine measurement, cytokine secretion following in vitro stimulation of blood circulating monocytes and whole blood RNA sequencing. The role of ORF3a SARS-CoV2 protein was assessed by confocal microscopy analysis following nucleofection of a monocytic cell line.

RESULTS

We found that circulating monocytes from COVID-19 patients display ASC specks that colocalize with NLRP3 inflammasome and spontaneously secrete IL-1β in vitro. This spontaneous activation reverts following patient's treatment with the IL-1 receptor antagonist anakinra. Transfection of a monocytic cell line with cDNA coding for the ORF3a SARS-CoV2 protein, resulted in ASC speck formation CONCLUSIONS: These results provide further evidence that IL-1β targeting could represent an effective strategy in this disease and suggest a mechanistic explanation for the strong inflammatory manifestations associated to COVID-19.

Uveal Melanoma Metastasis

Uveal melanoma (UM) is characterized by relatively few, highly incident molecular alterations and their association with metastatic risk is deeply understood. Nevertheless, this knowledge has so far not led to innovative therapies for the successful treatment of UM metastases or for adjuvant therapy, leaving survival after diagnosis of metastatic UM almost unaltered in decades. The driver mutations of UM, mainly in the G-protein genes GNAQ and GNA11, activate the MAP-kinase pathway as well as the YAP/TAZ pathway. At present, there are no drugs that target the latter and this likely explains the failure of mitogen activated kinase kinase inhibitors. Immune checkpoint blockers, despite the game changing effect in cutaneous melanoma (CM), show only limited effects in UM probably because of the low mutational burden of 0.5 per megabase and the unavailability of antibodies targeting the main immune checkpoint active in UM. The highly pro-tumorigenic microenvironment of UM also contributes to therapy resistance. However, T-cell redirection by a soluble T-cell receptor that is fused to an anti-CD3 single-chain variable fragment, local, liver specific therapy, new immune checkpoint blockers, and YAP/TAZ specific drugs give new hope to repeating the success of innovative therapy obtained for CM.

Feasibility, tolerability, and safety of hysterosalpingo-foam sonography (hyfosy). multicenter, prospective Spanish study

OBJECTIVE

To determine the feasibility,tolerability, and safety of the ultrasound assessment of tubal patency using foam as contrast.

METHODS

This was a prospective multicenter study of 915 infertile nulliparous women scheduled for sonohysterosalpingography with foam instillation (HYFOSY) for tubal patency testing as a part of the fertility workup. Clinical and sonographic data were recorded into a web-shared database. Tubal patency, cervical catheterization, pain during the procedure and post-procedural complications were collected. Patients reported discomfort or pain experienced during the procedure with a visual analogue scale (VAS) score.

RESULTS

Nine hundred fifteen women were included in the final analysis. Median age was 34 (range, 21-45) years and median body mass index was 23 (range, 16-41) kg/m2. Of 839 women, only 8(0.95 %) cases were abandoned due to impossibility of introducing the intracervical catheter. Most of the cervical os were easily cannulated with either paediatric nasogastric probes or special catheter for intrauterine insemination / sonohysterosalpingography 688/914(75.3 %). With a median instillation of 4 mL (range 1-16) of foam, both tubes were identified in 649/875 (70.9 %) patients, while unilateral patency was observed in 190/875 (20.8 %). Only 36/875 (3.9 %) of the women had bilateral tubal obstruction. The median VAS score for perception of pain during HyFoSy examination was 2 (range 0-10), and only 17 (1.9 %) of women reported severe pain (VAS ≥ 7). Pain was unrelated to tubal patency or tubal blockage. Unexpectedly, difficult cervical catheterizations that needed tenaculum, were more likely associated with mild pain during procedure [nasogastric probe group 176/289 (70.9 %) vs. insemination catheter group 166/399 (41.6 %) vs. tenaculum group 190/218(87.2 %) p < 0.001]. Finally, among 915 patients, we only noticed 3 (0.32 %) complications of the technique: two vasovagal episodes and a mild urinary infection.

CONCLUSION

HYFOSY is a feasible, well-tolerated and safe technique for the evaluation of tubal patency in infertile women.

Identification of a Prognostic Signature Based on the Expression of Genes Related to the Insulin Pathway in Early Breast Cancer

Introduction

Insulin and the insulin-like growth factor (IGF) family play a key role in breast cancer (BC).

Objective

In this study, we evaluated on a genomic scale the potential prognostic value of insulin signaling in early BC.

Methods

Candidate genes were selected from the published literature and gene expression profiling experiments. Three publicly available BC datasets, containing gene expression data on 502 cases, were used to test the prognostic ability of the score. The gene signature was developed on GSE1456, containing microarray data from 159 patients, split into a training set (102 breast tumors) and a validation set (n = 57). GSE3494 and GSE2990 (350 patients) were used for external validation. Univariate Mann-Whitney test was used to identify genes differentially expressed between relapsed and nonrelapsed patients. Expression of genes significantly correlated with relapse was combined in a linear score. Patients were classified as low or high risk with respect to the median value.

Results

On the training set, 15 genes turned out to be differentially expressed: 8-year disease-free survival (DFS) was 51 and 91% in the high- and low-risk group (p < 0.001), respectively. In the validation set, DFS was 97 and 54% (p = 0.009), respectively. External validation: 8-year DFS was 72 and 61%, respectively, in GSE3494 (p = 0.03) and 74 and 55% in GSE2990 (p = 0.03). By multivariate analyses, the insulin signature was significantly associated with DFS, independently of age, hormone receptor status, nodal status, and grade.

Conclusions

Our findings indicate that the insulin pathway is involved in BC prognosis at a genomic level and provide a window of selectivity for preventive and treatment strategies targeting the insulin/IGF pathway in BC patients.

Combined Replenishment of miR-34a and let-7b by Targeted Nanoparticles Inhibits Tumor Growth in Neuroblastoma Preclinical Models

Neuroblastoma (NB) tumor substantially contributes to childhood cancer mortality. The design of novel drugs targeted to specific molecular alterations becomes mandatory, especially for high-risk patients burdened by chemoresistant relapse. The dysregulated expression of MYCN, ALK, and LIN28B and the diminished levels of miR-34a and let-7b are oncogenic in NB. Due to the ability of miRNA-mimics to recover the tumor suppression functions of miRNAs underexpressed into cancer cells, safe and efficient nanocarriers selectively targeted to NB cells and tested in clinically relevant mouse models are developed. The technology exploits the nucleic acids negative charges to build coated-cationic liposomes, then functionalized with antibodies against GD₂ receptor. The replenishment of miR-34a and let-7b by NB-targeted nanoparticles, individually and more powerfully in combination, significantly reduces cell division, proliferation, neoangiogenesis, tumor growth and burden, and induces apoptosis in orthotopic xenografts and improves mice survival in pseudometastatic models. These functional effects highlight a cooperative down-modulation of MYCN and its down-stream targets, ALK and LIN28B, exerted by miR-34a and let-7b that reactivate regulatory networks leading to a favorable therapeutic response. These findings demonstrate a promising therapeutic efficacy of miR-34a and let-7b combined replacement and support its clinical application as adjuvant therapy for high-risk NB patients.

Secondary Somatic Mutations in G-Protein-Related Pathways and Mutation Signatures in Uveal Melanoma

BACKGROUND

Uveal melanoma (UM), a rare cancer of the eye, is characterized by initiating mutations in the genes G-protein subunit alpha Q (GNAQ), G-protein subunit alpha 11 (GNA11), cysteinyl leukotriene receptor 2 (CYSLTR2), and phospholipase C beta 4 (PLCB4) and by metastasis-promoting mutations in the genes splicing factor 3B1 (SF3B1), serine and arginine rich splicing factor 2 (SRSF2), and BRCA1-associated protein 1 (BAP1). Here, we tested the hypothesis that additional mutations, though occurring in only a few cases ("secondary drivers"), might influence tumor development.

METHODS

We analyzed all the 4125 mutations detected in exome sequencing datasets, comprising a total of 139 Ums, and tested the enrichment of secondary drivers in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways that also contained the initiating mutations. We searched for additional mutations in the putative secondary driver gene protein tyrosine kinase 2 beta (PTK2B) and we developed new mutational signatures that explain the mutational pattern observed in UM.

RESULTS

Secondary drivers were significantly enriched in KEGG pathways that also contained GNAQ and GNA11, such as the calcium-signaling pathway. Many of the secondary drivers were known cancer driver genes and were strongly associated with metastasis and survival. We identified additional mutations in PTK2B. Sparse dictionary learning allowed for the identification of mutational signatures specific for UM.

CONCLUSIONS

A considerable part of rare mutations that occur in addition to known driver mutations are likely to affect tumor development and progression.

Data Fusion Techniques for the Integration of Multi-Domain Genomic Data from Uveal Melanoma

Uveal melanoma (UM) is a rare cancer that is well characterized at the molecular level. Two to four classes have been identified by the analyses of gene expression (mRNA, ncRNA), DNA copy number, DNA-methylation and somatic mutations yet no factual integration of these data has been reported. We therefore applied novel algorithms for data fusion, joint Singular Value Decomposition (jSVD) and joint Constrained Matrix Factorization (jCMF), as well as similarity network fusion (SNF), for the integration of gene expression, methylation and copy number data that we applied to the Cancer Genome Atlas (TCGA) UM dataset. Variant features that most strongly impact on definition of classes were extracted for biological interpretation of the classes. Data fusion allows for the identification of the two to four classes previously described. Not all of these classes are evident at all levels indicating that integrative analyses add to genomic discrimination power. The classes are also characterized by different frequencies of somatic mutations in putative driver genes (GNAQ, GNA11, SF3B1, BAP1). Innovative data fusion techniques confirm, as expected, the existence of two main types of uveal melanoma mainly characterized by copy number alterations. Subtypes were also confirmed but are somewhat less defined. Data fusion allows for real integration of multi-domain genomic data.

Differential Expression of DNA Repair Genes in Prognostically-Favorable versus Unfavorable Uveal Melanoma

Expression of DNA repair genes was studied in uveal melanoma (UM) in order to identify genes that may play a role in metastases formation. We searched for genes that are differentially expressed between tumors with a favorable and unfavorable prognosis. Gene-expression profiling was performed on 64 primary UM from the Leiden University Medical Center (LUMC), Leiden, The Netherlands. The expression of 121 genes encoding proteins involved in DNA repair pathways was analyzed: a total of 44 genes differed between disomy 3 and monosomy 3 tumors. Results were validated in a cohort from Genoa and Paris and the The Cancer Genome Atlas (TCGA) cohort. Expression of the PRKDC, WDR48, XPC, and BAP1 genes was significantly associated with clinical outcome after validation. PRKDC was highly expressed in metastasizing UM (p < 0.001), whereas WDR48, XPC, and BAP1 were lowly expressed (p < 0.001, p = 0.006, p = 0.003, respectively). Low expression of WDR48 and XPC was related to a large tumor diameter (p = 0.01 and p = 0.004, respectively), and a mixed/epithelioid cell type (p = 0.007 and p = 0.03, respectively). We conclude that the expression of WDR48, XPC, and BAP1 is significantly lower in UM with an unfavorable prognosis, while these tumors have a significantly higher expression of PRKDC. Pharmacological inhibition of DNA-PKcs resulted in decreased survival of UM cells. PRKDC may be involved in proliferation, invasion and metastasis of UM cells. Unraveling the role of DNA repair genes may enhance our understanding of UM biology and result in the identification of new therapeutic targets.

miR-126-3p down-regulation contributes to dabrafenib acquired resistance in melanoma by up-regulating ADAM9 and VEGF-A

Background

Development of resistance to inhibitors of BRAF (BRAFi) and MEK (MEKi) remains a great challenge for targeted therapy in patients with BRAF-mutant melanoma. Here, we explored the role of miRNAs in melanoma acquired resistance to BRAFi.

Methods

miRNA expression in two BRAF-mutant melanoma cell lines and their dabrafenib-resistant sublines was determined using Affymetrix GeneChip® miRNA 3.1 microarrays and/or qRT-PCR. The effects of miR-126-3p re-expression on proliferation, apoptosis, cell cycle, ERK1/2 and AKT phosphorylation, dabrafenib sensitivity, invasiveness and VEGF-A secretion were evaluated in the dabrafenib-resistant sublines using MTT assays, flow cytometry, immunoblotting, invasion assays in Boyden chambers and ELISA. ADAM9, PIK3R2, MMP7 and CXCR4 expression in the sensitive and dabrafenib-resistant cells was determined by immunoblotting. Small RNA interference was performed to investigate the consequence of VEGFA or ADAM9 silencing on proliferation, invasiveness or dabrafenib sensitivity of the resistant sublines. Long-term proliferation assays were carried out in dabrafenib-sensitive cells to assess the effects of enforced miR-126-3p expression or ADAM9 silencing on resistance development. VEGF-A serum levels in melanoma patients treated with BRAFi or BRAFi+MEKi were evaluated at baseline (T0), after two months of treatment (T2) and at progression (TP) by ELISA.

Results

miR-126-3p was significantly down-regulated in the dabrafenib-resistant sublines as compared with their parental counterparts. miR-126-3p replacement in the drug-resistant cells inhibited proliferation, cell cycle progression, phosphorylation of ERK1/2 and/or AKT, invasiveness, VEGF-A and ADAM9 expression, and increased dabrafenib sensitivity. VEGFA or ADAM9 silencing impaired proliferation and invasiveness of the drug-resistant sublines. ADAM9 knock-down in the resistant cells increased dabrafenib sensitivity, whereas miR-126-3p enforced expression or ADAM9 silencing in the drug-sensitive cells delayed the development of resistance. At T0 and T2, statistically significant differences were observed in VEGF-A serum levels between patients who responded to therapy and patients who did not. In responder patients, a significant increase of VEGF-A levels was observed at TP versus T2.

Conclusions

Strategies restoring miR-126-3p expression or targeting VEGF-A or ADAM9 could restrain growth and metastasis of dabrafenib-resistant melanomas and increase their drug sensitivity. Circulating VEGF-A is a promising biomarker for predicting patients’ response to BRAFi or BRAFi+MEKi and for monitoring the onset of resistance.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1238-4) contains supplementary material, which is available to authorized users.

Curcumin induces a fatal energetic impairment in tumor cells in vitro and in vivo by inhibiting ATP-synthase activity

Curcumin has been reported to inhibit inflammation, tumor growth, angiogenesis and metastasis by decreasing cell growth and by inducing apoptosis mainly through the inhibition of nuclear factor kappa-B (NFκB), a master regulator of inflammation. Recent reports also indicate potential metabolic effects of the polyphenol, therefore we analyzed whether and how it affects the energy metabolism of tumor cells. We show that curcumin (10 µM) inhibits the activity of ATP synthase in isolated mitochondrial membranes leading to a dramatic drop of ATP and a reduction of oxygen consumption in in vitro and in vivo tumor models. The effects of curcumin on ATP synthase are independent of the inhibition of NFκB since the IκB Kinase inhibitor, SC-514, does not affect ATP synthase. The activities of the glycolytic enzymes hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase are only slightly affected in a cell type-specific manner. The energy impairment translates into decreased tumor cell viability. Moreover, curcumin induces apoptosis by promoting the generation of reactive oxygen species (ROS) and malondialdehyde (MDA), a marker of lipid oxidation, and autophagy, at least in part due to the activation of the AMP-activated protein kinase (AMPK). According to the in vitro anti-tumor effect, curcumin (30 mg/kg body weight) significantly delayed in vivo cancer growth likely due to an energy impairment but also through the reduction of tumor angiogenesis. These results establish the ATP synthase, a central enzyme of the cellular energy metabolism, as a target of the antitumoral polyphenol leading to inhibition of cancer cell growth and a general reprogramming of tumor metabolism.

Prognostic value of chromosomal imbalances, gene mutations, and BAP1 expression in uveal melanoma

Uveal melanoma (UM) exhibits recurring chromosomal abnormalities and gene driver mutations, which are related to tumor evolution/progression. Almost half of the patients with UM develop distant metastases, predominantly to the liver, and so far there are no effective adjuvant therapies. An accurate UM genetic profile could assess the individual patient's metastatic risk, and provide the basis to determine an individualized targeted therapeutic strategy for each UM patient. To investigate the presence of specific chromosomal and gene alterations, BAP1 protein expression, and their relationship with distant progression free survival (DPFS), we analyzed tumor samples from 63 UM patients (40 men and 23 women, with a median age of 64 years), who underwent eye enucleation by a single cancer ophthalmologist from December 2005 to June 2016. UM samples were screened for the presence of losses/gains in chromosomes 1p, 3, 6p, and 8q, and for mutations in GNAQ, GNA11, BAP1, SF3B1, and EIF1AX. BAP1 protein expression was detected by immunohistochemistry (IHC). Multivariate analysis showed that the presence of monosomy 3, 8q gain, and loss of BAP1 protein were significantly associated to DPFS, while BAP1 gene mutation was not, mainly due to the presence of metastatic UM cases with negative BAP1 IHC and no BAP1 mutation detected by Sanger sequencing. Loss of BAP1 protein expression and monosomy 3 represent the strongest predictors of metastases, and may have important implications for implementation of patient surveillance, properly designed clinical trials enrollment, and adjuvant therapy.

Abstract 3513: Curcumin induces a fatal energetic impairment by inhibiting ATP-synthase activity and decreasing ATP generation and oxygen consumption in in vitro and in vivo tumor models

Curcumin has been reported to inhibit inflammation, tumor growth, angiogenesis and metastasis by decreasing cell growth and by inducing apoptosis mainly through the inhibition of nuclear factor kappa-B (NFkB), a master regulator of inflammation. Recent reports also indicate potential metabolic effects of the polyphenol and we therefore analyzed whether and how it affects the energy metabolism of tumor cells. We show that curcumin inhibits the activity of ATP-synthase in isolated mitochondrial membranes leading to a dramatic drop of ATP and a reduction of oxygen consumption in in vitro in several murine tumor cell lines (CT26 colon cancer, B16 melanoma, L1210 lymphocytic leukemia, 4T1 breast cancer) and in vivo in syngeneic tumor models. The effects of curcumin on ATP-synthase are independent of the inhibition of nuclear factor kB (NFkB) since the IkB Kinase inhibitor, SC-514, inhibits the expression of the NFkB target gene, BCL2, but does not affect the activity of the ATP-synthase. The activities of the glucose metabolism enzymes hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase are only slightly affected in a cell type specific manner. The energy impairment translates into decreased tumor cell viability. Apoptosis is induced by promoting the generation of reactive oxygen species and malondialdehyde (MDA), a marker of lipid oxidation. Tumor autophagy is induced by curcumin at least in part due to the activation of the AMP-activated protein kinase (AMPK). These activities translate into a significant delay of in vivo tumor growth likely due to a reduction of tumor angiogenesis since we observe reduced number and size of tumor vessels in vivo. These results establish the ATP-synthase, a central enzyme of the cellular energy metabolism, as a target of the anti-tumoral polyphenol leading to inhibition of cancer cell growth and a general reprogramming of tumor metabolism.

Citation Format: Ulrich Pfeffer, Giovanna Bianchi, Silvia Ravera, Chiara Traverso, Adriana Amaro, Francesca Piaggio, Laura Emionite, Tiziana Bacchetti, Lizzia Raffaghello. Curcumin induces a fatal energetic impairment by inhibiting ATP-synthase activity and decreasing ATP generation and oxygen consumption in in vitro and in vivo tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3513.

Abstract 474: Alterations of micro-RNAs are associated with melanoma resistance to BRAF inhibitors: Role of miR-126

Altered expression of miRNAs has been demonstrated in tumor tissue and plasma/serum of cancer patients. miRNAs have been shown to have both diagnostic and prognostic significance and to potentially constitute novel targets and therapeutic agents for cancer treatment. Experimental evidences also support an involvement of miRNAs in tumor cell response to therapy. In this study, we explored the role of miRNAs in melanoma resistance to BRAF inhibitors (BRAFi). The melanoma cell line A375 and its dabrafenib-resistant subline A375R, which displays increased invasiveness and VEGF secretion, were analyzed for miRNA expression using Affymetrix GeneChip® miRNA 3.1 microarrays. Differential expression of selected miRNAs was confirmed in the two cell lines using qRT-PCR. miR-126, previously shown to act as a tumor suppressor gene in melanoma, was chosen for additional studies that were performed also in a second pair of matched melanoma cell lines, sensitive or resistant to dabrafenib (i.e SK-Mel28 and SK-Mel28R). The resistant sublines were transfected with 50 nM Pre-miR hsa-miR-126 miRNA Precursor (pre-miRNA-126) or Pre-miR miRNA Precursor Negative Control#1 (Ambion®) and analyzed for proliferation 6 days later using the MTT assay. Seventy-two hours after transfection, the cells were also assayed for invasion of the extracellular matrix and VEGF-A secretion using Boyden Chamber and ELISA assays, respectively. In 33 melanoma patients treated with BRAFi, alone or in combination with MEKi, plasma samples were collected before the beginning of therapy (T0), and two months later (T2) and subjected to miRNA expression profiling by small RNA-seq. A375R cells displayed 13 up-regulated miRNAs and 32 down-regulated miRNAs with respect to A375 cells (SAM analysis; fold change ≥ 2). Down-regulation of miR-126 was confirmed by qRT-PCR analysis in both A375R and SK-Mel28R cells. Restoration of miR-126 expression in A375R and SK-Mel28R cells by pre-miRNA-126 transfection impaired proliferation, invasion and secretion of VEGF-A, a validated target of miR-126. Fifthy and 28 circulating miRNAs were differentially expressed at T0 and at T2, respectively, between patients who responded to therapy (n=28) and patients who did not (n=5). Our results demonstrate that down-regulation of miR-126 expression is associated with acquired resistance to dabrafenib in melanoma cells and suggest that restoration of this miRNA in dabrafenib-resistant melanomas might restrain tumor growth and metastasis. They also show that in melanoma patients with primary resistance to BRAFi, a set of circulating miRNAs is differentially expressed with respect to patients responding to therapy, suggesting a potential role of circulating miRNAs as biomarkers for early prediction of drug response. Supported by the Italian Ministry of Health, grant 5PerMille-2010 and AIRC, IGP 17585

Citation Format: Simona Caporali, Lauretta Levati, Ester Alvino, Adriana Amaro, Pedro Miguel Lacal, Laura Bonmassar, Cristian Bassi, Laura Lupini, Gian Carlo Antonini Cappellini, Ulrich Pfeffer, Massimo Negrini, Nadia Felli, Alessandra Carè, Giandomenico Russo, Stefania D'Atri. Alterations of micro-RNAs are associated with melanoma resistance to BRAF inhibitors: Role of miR-126 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 474.

A highly invasive subpopulation of MDA-MB-231 breast cancer cells shows accelerated growth, differential chemoresistance, features of apocrine tumors and reduced tumorigenicity in vivo

The acquisition of an invasive phenotype is a prerequisite for metastasization, yet it is not clear whether or to which extent the invasive phenotype is linked to other features characteristic of metastatic cells. We selected an invasive subpopulation from the triple negative breast cancer cell line MDA-MB-231, performing repeated cycles of preparative assays of invasion through Matrigel covered membranes. The invasive sub-population of MDA-MB-231 cells exhibits stronger migratory capacity as compared to parental cells confirming the highly invasive potential of the selected cell line. Prolonged cultivation of these cells did not abolish the invasive phenotype. ArrayCGH, DNA index quantification and karyotype analyses confirmed a common genetic origin of the parental and invasive subpopulations and revealed discrete structural differences of the invasive subpopulation including increased ploidy and the absence of a characteristic amplification of chromosome 5p14.1-15.33. Gene expression analyses showed a drastically altered expression profile including features of apocrine breast cancers and of invasion related matrix-metalloproteases and cytokines. The invasive cells showed accelerated proliferation, increased apoptosis, and an altered pattern of chemo-sensitivity with lower IC50 values for drugs affecting the mitotic apparatus. However, the invasive cell population is significantly less tumorigenic in orthotopic mouse xenografts suggesting that the acquisition of the invasive capacity and the achievement of metastatic growth potential are distinct events.

Analysis of the Expression and Single-Nucleotide Variant Frequencies of the Butyrophilin-like 2 Gene in Patients With Uveal Melanoma

Importance

Chromosome 6p amplification is associated with more benign behavior for uveal melanomas (UMs) with an otherwise high risk of metastasis conferred by chromosome 3 monosomy. Chromosome 6p contains several members of the B7 family of immune regulator genes, including butyrophilin-like 2 (BTNL2; OMIM, 606000), which is associated with prostate cancer risk and autoimmune diseases.

Objective

To investigate the expression and variant allele frequencies of BTNL2, a candidate gene for chromosome 6 amplification, in patients with UM.

Design, Setting, and Participants

In this case-control study, we analyzed the expression of BTNL2 in UM cell lines and human macrophages in patients with UM. Variants of BTNL2 were analyzed using probes for polymerase chain reaction and high-resolution melting. The association of missense variants rs28362679 and rs41441651 with tumor risk was analyzed in 209 patients with UM and 116 matched control patients as well as 12 UM and 64 other tumor cell lines. Genes that were differentially expressed in M1- and M2-polarized macrophages were identified by microarray analysis of 111 patients with UM, and the association of the expression of these genes with disease-free survival was analyzed by Cox regression analysis. Data were collected from September 2013 to November 2015.

Main Outcomes and Measures

Butyrophilin-like 2 single-nucleotide variants were associated with UM risk; M1 and M2 macrophage-specific gene expression was associated with disease-free survival.

Results

We genotyped a total of 325 patients. Of the 209 patients with UM, 124 (59.3%) were male, 114 (54.5%) were Italian, and 95 (45.5%) were German; the mean (range) age was 65 (27-94) years. Of the 116 Italian control patients, 67 (57.8%) were female, and the mean (range) age was 39 (21-88) years. Butyrophilin-like 2 is expressed in patients with UM and macrophages. The frequency of the rs28362679 variant was higher in patients with UM (16 of 209 [7.7%]; 95% CI, 4.7-12.2) than frequencies from European Variation Archive and Exome Aggregation Consortium data (2134 of 118 564 [1.8%]; 95% CI, 1.7-1.9) and Exome Sequencing Project data (100 of 4540 [2.2%]; 95% CI, 1.8-2.7) but were not higher compared with Italian control patients (10 of 116 [8.6%]; 95% CI, 4.6-15.4). The rs41441651 variant was present in 5 patients with UM (2.4%; 95% CI, 0.9-5.7), 2 Italian control patients (1.7%; 95% CI, 0.1-6.5), 2846 patients from European Variation Archive and Exome Aggregation Consortium data (2.4%; 95% CI, 2.3-2.5), and 23 patients from Exome Sequencing Project data (0.5%; 95% CI, 0.3-0.8). Human UM cells express M1 and M2 macrophage-specific genes, whose expression is associated with disease-free survival.

Conclusions and Relevance

Butyrophilin-like 2, expressed at various levels by UM cells and macrophages, might interfere with the immune control of the tumor. Butyrophilin-like 2 variants showed highly variable frequencies among ethnically related cohorts. There was no enrichment of BTNL2 variants in patients with UM compared with control patients.

The biology of uveal melanoma

Uveal melanoma (UM), a rare cancer of the eye, is distinct from cutaneous melanoma by its etiology, the mutation frequency and profile, and its clinical behavior including resistance to targeted therapy and immune checkpoint blockers. Primary disease is efficiently controlled by surgery or radiation therapy, but about half of UMs develop distant metastasis mostly to the liver. Survival of patients with metastasis is below 1 year and has not improved in decades. Recent years have brought a deep understanding of UM biology characterized by initiating mutations in the G proteins GNAQ and GNA11. Cytogenetic alterations, in particular monosomy of chromosome 3 and amplification of the long arm of chromosome 8, and mutation of the BRCA1-associated protein 1, BAP1, a tumor suppressor gene, or the splicing factor SF3B1 determine UM metastasis. Cytogenetic and molecular profiling allow for a very precise prognostication that is still not matched by efficacious adjuvant therapies. G protein signaling has been shown to activate the YAP/TAZ pathway independent of HIPPO, and conventional signaling via the mitogen-activated kinase pathway probably also contributes to UM development and progression. Several lines of evidence indicate that inflammation and macrophages play a pro-tumor role in UM and in its hepatic metastases. UM cells benefit from the immune privilege in the eye and may adopt several mechanisms involved in this privilege for tumor escape that act even after leaving the niche. Here, we review the current knowledge of the biology of UM and discuss recent approaches to UM treatment.

Molecular evolution of colorectal cancer: from multistep carcinogenesis to the big bang

Colorectal cancer is characterized by exquisite genomic instability either in the form of microsatellite instability or chromosomal instability. Microsatellite instability is the result of mutation of mismatch repair genes or their silencing through promoter methylation as a consequence of the CpG island methylator phenotype. The molecular causes of chromosomal instability are less well characterized. Genomic instability and field cancerization lead to a high degree of intratumoral heterogeneity and determine the formation of cancer stem cells and epithelial-mesenchymal transition mediated by the TGF-β and APC pathways. Recent analyses using integrated genomics reveal different phases of colorectal cancer evolution. An initial phase of genomic instability that yields many clones with different mutations (big bang) is followed by an important, previously not detected phase of cancer evolution that consists in the stabilization of several clones and a relatively flat outgrowth. The big bang model can best explain the coexistence of several stable clones and is compatible with the fact that the analysis of the bulk of the primary tumor yields prognostic information.

Fasting induces anti-Warburg effect that increases respiration but reduces ATP-synthesis to promote apoptosis in colon cancer models

Tumor chemoresistance is associated with high aerobic glycolysis rates and reduced oxidative phosphorylation, a phenomenon called "Warburg effect" whose reversal could impair the ability of a wide range of cancer cells to survive in the presence or absence of chemotherapy. In previous studies, Short-term-starvation (STS) was shown to protect normal cells and organs but to sensitize different cancer cell types to chemotherapy but the mechanisms responsible for these effects are poorly understood. We tested the cytotoxicity of Oxaliplatin (OXP) combined with a 48hour STS on the progression of CT26 colorectal tumors. STS potentiated the effects of OXP on the suppression of colon carcinoma growth and glucose uptake in both in vitro and in vivo models. In CT26 cells, STS down-regulated aerobic glycolysis, and glutaminolysis, while increasing oxidative phosphorylation. The STS-dependent increase in both Complex I and Complex II-dependent O(2) consumption was associated with increased oxidative stress and reduced ATP synthesis. Chemotherapy caused additional toxicity, which was associated with increased succinate/Complex II-dependent O(2) consumption, elevated oxidative stress and apoptosis .These findings indicate that the glucose and amino acid deficiency conditions imposed by STS promote an anti-Warburg effect characterized by increased oxygen consumption but failure to generate ATP, resulting in oxidative damage and apoptosis.

Abstract 1149: Consistency between genomic and proteomic profiles reveals novel molecular mechanisms of fasting antitumor activity

Background/Aim

Fasting or Short term Starvation (STS) represents a novel therapeutic strategy which appears to: i) protect normal but not tumor cells against the chemotherapy-mediated cytotoxicity, ii) induce a potent chemosensitizing effect in a wide range of experimental tumor model, and iii) be feasible, safe and able to reduce common side effects induced by chemotherapy in cancer patients. In addition, fasting alone has been shown to retard in vitro and in vivo tumor growth. However, the molecular mechanisms coupling STS with antitumor activity remain only partially understood. Thus, aim of this study is to investigate the modulation of the genomic and proteomic profiles by fasting in cancer cells with particular attention to elements involved in cell growth and metabolism signaling pathways.

Methods

Tumor cell lines were cultured under control (glucose: 1 g/L + 10% fetal bovine serum) or starved (glucose: 0.5 g/L + 1% fetal bovine serum) conditions for 48 hours. The in vitro viability of STS was tested by Trypan Blue staining and Annexin V apoptosis assay. Tumor cell proliferation was evaluated by 5-bromo-2-deoxyuridine (BrdU) and Carboxyfluorescein Succinimidyl ester (CFSE) staining. Gene expression was tested by microarray analysis. Protein expression were studied by western blot and Label Free Quantitation (LFQ) on High Resolution/Mass Accuracy Liquid Chromatography Tandem Mass Spectrometry (HR/MA LC MS/MS). Proteomic data were evaluated by network analysis using Cytoscape.

Results

In vitro experiments showed that STS significantly reduced cell proliferation and promoted apoptosis. The latter effect was mediated by a fine regulation of genes and proteins involved in cell growth and metabolic signaling pathways. In particular, STS significantly reduced the expression of elements of PI3K/AKT pathway and glycolytic enzymes. This latter modulation likely occurred at the transcriptional level since the expression profiles of STS treated cells showed a clear down-regulation of the genes encoding these enzymes as compared to untreated controls. STS also down-regulated glutaminase both at the mRNA and protein level. In contrast, proteomic and genomic analyses of the expression of oxidative phosphorylation enzymes did not show a clear up-regulation effect by STS. Finally, preliminary data revealed that STS modulates genes and proteins involved in Jak/STAT, MAPK pathways and ubiquitin mediated proteolysis. Noteworthy, for 90% of genes down- or up-regulated by STS for which a protein was identified by HR/MA LC MS/MS, a corresponding mRNA level was modulated by STS with a similar trend.

Conclusions

Taken together, the genomic and proteomic profiles demonstrated that STS caused an anti-Warburg effect and downregulated proliferation and inflammatory pathways. These findings open a novel scenario in cancer treatment.

Citation Format: Lizzia Raffaghello, Giovanna Bianchi, Roberto Martella, Danilo Marimpietri, Andrea Petretto, Elvira Inglese, Adriana Amaro, Vito Pistoia, Ulrich Pfeffer, Valter Longo. Consistency between genomic and proteomic profiles reveals novel molecular mechanisms of fasting antitumor activity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1149. doi:10.1158/1538-7445.AM2015-1149

Abstract 1182: Metformin affects breast cancer cell growth and disturbs an IGF1/insulin related gene network that correlates with breast cancer progression

Background

Obesity and the insulin resistance syndrome are risk factors for breast cancer and might also affect breast cancer progression. The anti-diabetic drug Metformin (METF) reduces the breast cancer risk in diabetic women. Insulin like growth factor 1 (IGF1) and insulin are involved in breast cancer tumorigenesis and progression.

We tested the effect of METF on the IGF1/insulin pathway and its involvement in breast cancer progression.

Methods

We developed a prognostic signature based on IGF1/insulin pathway genes using the Stockholm breast cancer microarray dataset of 149 cases for training and primary validation and the Uppsala dataset of 249 for external validation. The effect of METF on the prognostic gene set identified was tested in vitro on a panel of breast cancer cell lines. METF effects on proliferation and glucose metabolism were analyzed in vitro and in vivo. The insulin receptor substrate 2 (IRS2) was silenced by transfection with shRNA-lentiviral vectors. Xenograft growth, in the presence and absence of METF, was studied and 18FDG-uptake was measured in vitro and in vivo.

Results

A 15-gene signature (Insulin sensitivity score, ISS) was developed and predicted breast cancer metastasis with an accuracy similar to the Recurrence Score. ISS genes were expressed at variable levels in a breast cancer cell line panel and showed variable responsiveness to METF. The high expression correlation among the ISS genes observed in untreated breast cancer cell lines was lost upon treatment with METF. METF reduced breast cancer cell growth in vitro with IC50 values ranging from 1mM to 25mM. Growth of MDA-MB-231 cells and hyper-invasive subpopulations derived therefrom was reduced in vivo by oral administration of METF to xenografted nude mice. Response to METF in terms of IC50 values correlated with basal expression of the 15 ISS genes with the strongest inverse correlation observed for IRS2. Stable silencing of IRS2 reduced the MDA-231 cell responsiveness to METF in vitro.

Discussion

METF acts on the insulin/IGF1 axis by disturbing a network of breast cancer progression related genes and appears to depend in its action on the expression of IRS2 that inversely correlates with the sensitivity of cell lines to the drug. The disruption of the ISS gene network is expected to correlate with an effect on breast cancer growth and progression and in fact, mouse xenografts show reduced growth upon treatment with METF. IRS2 appears to be a major mediator of METF effects.

Citation Format: Alessia I. Esposito, Adriana Amaro, Giovanna Angelini, Laura Emionite, Alessandra Gennari, Stefano Indraccolo, Davide Maggi, Cecilia Marini, Barabara Salani, Gianmario Sambuceti, Maria Pia Sormani, Ulrich Pfeffer. Metformin affects breast cancer cell growth and disturbs an IGF1/insulin related gene network that correlates with breast cancer progression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1182. doi:10.1158/1538-7445.AM2015-1182

IGF1 regulates PKM2 function through Akt phosphorylation

Pyruvate kinase M2 (PKM2) acts at the crossroad of growth and metabolism pathways in cells. PKM2 regulation by growth factors can redirect glycolytic intermediates into key biosynthetic pathway. Here we show that IGF1 can regulate glycolysis rate, stimulate PKM2 Ser/Thr phosphorylation and decrease cellular pyruvate kinase activity. Upon IGF1 treatment we found an increase of the dimeric form of PKM2 and the enrichment of PKM2 in the nucleus. This effect was associated to a reduction of pyruvate kinase enzymatic activity and was reversed using metformin, which decreases Akt phosphorylation. IGF1 induced an increased nuclear localization of PKM2 and STAT3, which correlated with an increased HIF1α, HK2, and GLUT1 expression and glucose entrapment. Metformin inhibited HK2, GLUT1, HIF-1α expression and glucose consumption. These findings suggest a role of IGFIR/Akt axis in regulating glycolysis by Ser/Thr PKM2 phosphorylation in cancer cells.

Exogenous hormonal regulation in breast cancer cells by phytoestrogens and endocrine disruptors

Observations on the role of ovarian hormones in breast cancer growth, as well as interest in contraception, stimulated research into the biology of estrogens. The identification of the classical receptors ERα and ERβ and the transmembrane receptor GPER and the resolution of the structure of the ligand bound to its receptor established the principal molecular mechanisms of estrogen action. The presence of estrogen-like compounds in many plants used in traditional medicine or ingested as food ingredients, phytoestrogens, as well as the estrogenic activities of many industrial pollutants and pesticides, xenoestrogens, have prompted investigations into their role in human health. Phyto- and xenoestrogens bind to the estrogen receptors with a lower affinity than the endogenous estrogens and can compete or substitute the hormone. Xenoestrogens, which accumulate in the body throughout life, are believed to increase breast cancer risk, especially in cases of prenatal and prepuberal exposure whereas the role of phytoestrogens is still a matter of debate. At present, the application of phytoestrogens appears to be limited to the treatment of post-menopausal symptoms in women where the production of endogenous estrogens has ceased. In this review we discuss chemistry, structure and classification, estrogen signaling and the consequences of the interactions of estrogens, phytoestrogens and xenoestrogens with their receptors, the complex interactions of endogenous and exogenous ligands, the evaluation of the health risks related to xenoestrogens, and the perspectives toward the synthesis of potent third generation selective estrogen receptor modulators (SERMs).

Direct inhibition of hexokinase activity by metformin at least partially impairs glucose metabolism and tumor growth in experimental breast cancer

Emerging evidence suggests that metformin, a widely used anti-diabetic drug, may be useful in the prevention and treatment of different cancers. In the present study, we demonstrate that metformin directly inhibits the enzymatic function of hexokinase (HK) I and II in a cell line of triple-negative breast cancer (MDA-MB-231). The inhibition is selective for these isoforms, as documented by experiments with purified HK I and II as well as with cell lysates. Measurements of ¹⁸F-fluoro-deoxyglycose uptake document that it is dose- and time-dependent and powerful enough to virtually abolish glucose consumption despite unchanged availability of membrane glucose transporters. The profound energetic imbalance activates phosphorylation and is subsequently followed by cell death. More importantly, the “in vivo” relevance of this effect is confirmed by studies of orthotopic xenografts of MDA-MB-231 cells in athymic (nu/nu) mice. Administration of high drug doses after tumor development caused an evident tumor necrosis in a time as short as 48 h. On the other hand, 1 mo metformin treatment markedly reduced cancer glucose consumption and growth. Taken together, our results strongly suggest that HK inhibition contributes to metformin therapeutic and preventive potential in breast cancer.

ADAM10 correlates with uveal melanoma metastasis and promotes in vitro invasion

Uveal melanoma (UM) is a rare ocular tumor that may lead to deadly metastases in 50% of patients. A disintegrin and metalloproteinase (ADAM)10, ADAM17, and the HGF-receptor c-Met support invasiveness in different tumors. Here, we report that high ADAM10, MET, and, to a lesser extent, ADAM17 gene expression correlates with poor progression-free survival in UM patients (hazard ratio 2.7, 2.6, and 1.9, respectively). About 60% of primary UM expresses c-Met and/or ADAM10 proteins. Four UM cell lines display high levels of ADAM10 and ADAM17, which constitutively cleave c-Met, inducing the release of soluble c-Met. ADAM10/17 pharmacological inhibition or gene silencing reduces c-Met shedding, but has limited impact on surface c-Met, which is overexpressed. Importantly, ADAM10 silencing inhibits UM cell invasion driven by FCS or HGF, while ADAM17 silencing has a limited effect. Altogether our data indicate that ADAM10 has a pro-invasive role and may contribute to UM progression.

Metformin impairs glucose consumption and survival in Calu-1 cells by direct inhibition of hexokinase-II

The anti-hyperglycaemic drug metformin has important anticancer properties as shown by the direct inhibition of cancer cells proliferation. Tumor cells avidly use glucose as a source for energy production and cell building blocks. Critical to this phenotype is the production of glucose-6-phosphate (G6P), catalysed by hexokinases (HK) I and II, whose role in glucose retention and metabolism is highly advantageous for cell survival and proliferation. Here we show that metformin impairs the enzymatic function of HKI and II in Calu-1 cells. This inhibition virtually abolishes cell glucose uptake and phosphorylation as documented by the reduced entrapment of ¹⁸F-fluorodeoxyglucose. In-silico models indicate that this action is due to metformin capability to mimic G6P features by steadily binding its pocket in HKII. The impairment of this energy source results in mitochondrial depolarization and subsequent cell death. These results could represent a starting point to open effective strategies in cancer prevention and treatment.

Evidence of epidermal growth factor receptor expression in uveal melanoma: inhibition of epidermal growth factor-mediated signalling by Gefitinib and Cetuximab triggered antibody-dependent cellular cytotoxicity

Despite advances in surgery and radiotherapy of uveal melanoma (UM), many patients develop distant metastases that poorly respond to therapy. Improved therapies for the metastatic disease are therefore urgently needed. Expression of the epidermal growth factor receptor (EGFR), a target of kinase inhibitors and humanised antibodies in use for several cancers, had been reported. Forty-eight human UMs were analysed by expression profiling. Signalling was tested in three EGFR expressing UM cell lines by Western blotting using phosphorylation specific antibodies for EGFR and the downstream mediators AKT (v-akt murine thymoma viral oncogene homolog) and extracellular signal-regulated kinase (ERK). Evidence for signalling in tumours was obtained through the application of a UM-specific EGF-signature. The EGFR specific kinase inhibitor, Gefitinib and the humanised monoclonal antibody, Cetuximab, were tested for their effect on EGFR signalling. Natural killer cell mediated antibody-dependent cellular cytotoxicity (ADCC) and tumour necrosis factor α (TNF-α) release was analysed for Cetuximab. Fourteen of 48 UMs and three of 14 cell lines (over-)express EGFR, at least in part due to trisomy of the EGFR locus on chromosome 7p12. EGFR and the downstream mediator, AKT, are phosphorylated upon stimulation with EGF in EGFR expressing cell lines. EGFR over-expressing tumours but not EGFR negative tumours show an activated EGF-signature. Gefitinib inhibits EGFR and AKT phosphorylation and Cetuximab induces EGFR phosphorylation but inhibits signalling to AKT induced with EGF. Cetuximab triggers natural killer (NK) cells to lyse EGFR+ cell lines and to release TNF-α. EGFR appears suited as a novel molecular drug target for therapy of uveal melanoma.

Metformin temporal and localized effects on gut glucose metabolism assessed using 18F-FDG PET in mice

In the course of metformin treatment, staging abdominal cancer lesions with (18)F-FDG PET images is often hindered by the presence of a high bowel radioactivity. The present study aimed to verify the mechanism underlying this phenomenon.

METHODS

Fifty-three mice were submitted to dynamic acquisitions of (18)F-FDG kinetics under fasting conditions. Three small-animal PET scans were obtained over a 4-mo study period. The animals were subdivided into 4 groups according to the following metformin administration protocol: group 1, untreated mice (n = 15); group 2, mice exposed to metformin treatment (750 mg/kg/d) for the 48 h before each PET study (pulsed, n = 10); group 3, mice treated for the whole study period (prolonged, n = 10); and group 4, mice in which prolonged treatment was interrupted 48 h before PET (interrupted, n = 8). The rate constant of (18)F-FDG uptake was estimated by Patlak analysis. At the end of the study, the ileum and colon were harvested, washed, and counted ex vivo. Two further groups, of 5 animals each, were included to evaluate the effect of prolonged metformin treatment on phosphorylated adenosine monophosphate (AMP)-activated protein kinase (pAMPK) form and gene expression for thioredoxin-interacting protein (TXNIP).

RESULTS

Pulsed treatment did not modify gut tracer retention with respect to the untreated group. Conversely, prolonged treatment induced a progressive increase in (18)F-FDG uptake that selectively involved the colonic wall, without any significant contamination of bowel content. This effect persisted after a complete drug washout in the interrupted group. These responses were paralleled by increased pAMPK availability and by reduced expression of TXNIP messenger RNA in colonic enterocytes exposed to prolonged metformin treatment.

CONCLUSION

Metformin causes a selective increase in colonic (18)F-FDG uptake. This effect appears after a relatively long period of treatment and persists soon after drug washout. Accordingly, the increased bowel glucose metabolism reflects a biologic response to chronic metformin treatment characterized by increased levels of pAMPK and reduced levels of TXNIP.

Abstract 496: Isolation and characterization of a highly invasive subpopulation from MDA-MB-231 breast cancer cells

The acquisition of an invasive phenotype is a pre-requisite for metastasis. We set out to develop cellular systems that can mirror transient and stbale molecular alterations that confer an invasive phenotype to breast cancer cells. We observed that it is possible to isolate invasive subpopulations from moderately invasive cancer cell lines. Enrichment of invasive sub-populations of MDA-MB-231 breast cancer cells in three successive preparative invasion assays in Matrigel covered Boyden chambers yielded a highly invasive cell line. Prolonged cultivation of these cells did not abolish the invasive phenotype although not all phenotypic changes acquired during selection are maintained by long term cultures. Genetic analyses of these cells by cytogenetics and array based comparative genome hybridization revealed many genetic alterations including increased ploidy. The flow cytometric DNA Index (DI) changes from 1.28 to 2.28. Cells with DI 2.28 constitute 1.4% of the parental cell line. Whole genome SNP analysis shows that the two populations are genetically related excluding any cell contamination. The invasive cells proliferate and undergo apoptosis similar to the parental cells. Commitment to apoptosis is increased since invasive cells respond more strongly to curcumin or peroxide induced apoptosis. Invasive cells show relative resistance to the cytotoxic, alkylating agent Doxorubicin and increased sensitivity to the anti-mitotic drugs Vincristine and Taxol. Increased resistance to the topoisomerase II inhibitor Mitoxantrone is observed only transiently in invasive cells and lost in long term cultures. Similarly, the chemokines CXCL1 and -2 are transiently upregulated. Response to the anti-diabetic drug Metformin showed a reduced sensibility for invasive cells in terms of growth inhibition (IC50). Gene expression profiling shows complex alterations in gene expression. Many of the genes that are differentially expressed in highly versus moderately invasive cells are differentially expressed in human breast cancer cases with and without distant metastasis and correlate with disease free survival. The invasive phenotype is not related to stem cell features nor to epithelial mesenchymal transition. These cells constitute a novel model for tumor progression. Tumorigenicity and metastatic potential in vivo are currently being tested.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 496. doi:1538-7445.AM2012-496

Gold nanoprobe assay for the identification of mycobacteria of the Mycobacterium tuberculosis complex

Members of the Mycobacterium tuberculosis complex (MTC) are causative agents of human and animal tuberculosis. This complex encompasses several phylogenetically related species, including M. tuberculosis, the main aetiological agent of human tuberculosis, and Mycobacterium bovis, the causative agent of bovine tuberculosis, a relevant worldwide zoonosis. Clear epidemiological evaluation of appropriate and effective treatment requires unambiguous differentiation between MTC members. Routine diagnosis has been increasingly relying on the molecular identification of MTC members. In the present study, we report the use of a gold nanoparticle-based approach for the sensitive, specific and fast identification of MTC and for the differentiation of M. bovis and M. tuberculosis using the gyrB locus as target. This gold nanoprobe strategy relies on the colorimetric differentiation of specific DNA sequences based on differential aggregation profiles in the presence or absence of specific target hybridization. Three nanoprobes were designed and successfully used for the specific identification of members of MTC, M. bovis and M. tuberculosis.

A prognostic multigene classifier for squamous cell carcinomas of the larynx

Survival after diagnosis of laryngeal cancer has not improved over the last 20 years. Selection of patients for radio- and chemotherapy or surgery or follow-up strategies based on a prognostic classifier could improve survival without unduly extending radical surgery. We performed microarray gene expression analysis and developed a four-gene classifier for laryngeal cancer using Prediction Analysis of Microarray and leave-one-out cross validation. A four-gene classifier containing the non-coding gene H19, the histone HIST1H3F and the two small nucleolar RNAs, SNORA16A and SNORD14C was developed that assigns cases to low and high risk classes. The high risk class has a relative risk of 6.5 (CI=1.817-23.258, Fisher exact test p<0.0001). The maternally imprinted gene H19 is the top classifier gene.

Blood COX-2 and PGES gene transcription during the peripartum period of dairy cows with normal puerperium or with uterine infection

In the dairy cow, puerperal uterine intra-luminal concentrations of PGE(2) are related to the establishment and severity of uterine infections. Here we evaluated whether the blood concentrations of PGE(2) and the gene transcription profiles of enzymes involved in its synthesis (cyclooxygenase-2 and prostaglandin E synthase) could be used as markers of predisposition and/or presence of puerperal uterine infections. We also studied the relationship between the endocrine status and the leukocyte profiles around parturition and the transcription patterns of the genes. Finally, we have characterized the in vitro gene transcription and expression response to a challenge of LPS. Gene transcription profiles, quantified by real-time PCR, were similar in normal puerperium and metritis/endometritis cows, indicating that they are not suitable markers of predisposition to/presence of puerperal uterine infections. Transcription decreased from 2 weeks before parturition until parturition, when a minimum was attained, and then increased during the first week postpartum. The lowest gene transcription, at parturition, was coincidental with the highest total leukocytes, polymorphonuclear neutrophils and CD14 positive cell numbers. It is suggested that by this mechanism, a large number of PMN can be recruited into the uterus after parturition, avoiding an excessive acute inflammatory response. The lowest gene transcription was also coincidental with the surge in cortisol concentrations, indicating that this hormone plays a main immunomodulatory role around parturition. Gene transcription was significantly greater after stimulation with LPS than in non-stimulated blood. We suggest that this PGE(2) producing cells might arrive to the uterine lumen, contributing to the local PGE(2) concentrations and mediating the inflammatory response.

Comparison of three DNA extraction methods for Mycobacterium bovis, Mycobacterium tuberculosis and Mycobacterium avium subsp. avium

AIMS

To compare three methods for DNA extraction from Mycobacterium bovis, Mycobacterium tuberculosis and Mycobacterium avium subsp. avium.

METHODS AND RESULTS

The DNA was extracted from mycobacterial cultures using enzymatic extraction, combined bead beating and enzymatic extraction and cetyltrimethylammonium bromide (CTAB) extraction. The yield and quality of DNA were compared by spectrophotometry, agarose gel electrophoresis, restriction endonuclease analysis and PCR. The combined bead beating and enzymatic extraction method yielded more DNA. However, that method produced some sheared DNA, visible either by agarose gel electrophoresis or by restriction endonuclease analysis. All methods were appropriate for PCR amplification of a 123 bp fragment of IS6110 in M. bovis and M. tuberculosis, and of a 1700 bp fragment of FR300 region in M. avium avium.

CONCLUSIONS

Combined bead beating and enzymatic extraction method was the most efficient and easy method for extracting DNA from bacteria of the M. tuberculosis complex.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results reveal important differences among the DNA extraction methods for mycobacteria, which are relevant for the success of further downstream molecular analysis.

Gluteus medius muscle atrophy is related to contralateral and ipsilateral hip joint osteoarthritis

In order to understand the role of the GLUTEUS MEDIUS muscle (GM) in hip joint osteoarthritis, the objective of this study was to analyze the correlation between morphometric data of GM samples with osteoarthritis scores of ipsilateral and contralateral hips in 41 patients. GM samples obtained during unilateral hip replacement surgery were used to evaluate muscle fibers in the cross-sectional area (CSA) and other features indicative for muscle aging. Clinical symptoms were assessed by the Lequesne pain score. Hip osteoarthritis was graded by the Kellgren score and by measuring the sum joint space width (sumJSW) at three different articular locations and minimal JSW in a. p. radiographs. Varying degrees of GM muscle atrophy correlated with the pain score; pain score also correlated with radiographic signs of osteoarthritis. GM CSA was significantly correlated with all radiographic signs of the contralateral hip, but only with the sumJSW in the ipsilateral hip. It can be concluded that a weak GM may be the result of ipsilateral osteoarthitis, but may especially predispose the contralateral hip to develop osteoarthritis. This can be associated with an impaired GM capacity to avoid the shock impact in the load transfer during gait. Muscle strengthening is therefore recommended.

Characteristics of the gluteus medius muscle in an asymptomatic patient with radiographic signs of coxarthrosis

This case study describes the micromorphology and some biochemical features of gluteus medius muscle in a 79-year-old woman with radiographic signs of coxarthrosis but with no clinical symptoms who initially was admitted in the orthopaedic emergency service with a non-displaced subcapital fracture of the femoral neck due to a domestic accident (fall). The X-ray of the hip showed some characteristic features of coxarthrosis, classified grade 2 of the Kellgren criteria. After informed consent, it was decided to carry out the functional evaluation according to the indexes of Lequesne and WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) and to take a biopsy of the gluteus medius muscle for microscopical examination and myosin heavy chain isoform identification during hip replacement surgery. For the Lequesne Index (score 0-24), the total score was 0, and for the WOMAC (score 0-96), the total score was also 0, both speaking in favour of full joint and muscle function. All the structural features observed in muscle were considered not to have any pathological relevance. The composition of the myosin heavy chains in the gluteus medius muscle was 48% MHC I, 41% MHC IIa, and 11% MHC IIx. The muscle characteristics do not support earlier concepts about muscle weakness as a predisposing factor for osteoarthritis. It is moreover concluded that the diagnosis should rather consider clinical symptoms than radiographic signs of osteoarthritis.

Screening of obstructive sleep apnoea: heart rate spectral analysis of nocturnal pulse oximetric recording

Using heart rate spectral analysis of nocturnal pulse oximetry, we prospectively evaluated the utility of this methodology in patients clinically suspected of having obstructive sleep apnoea (OSA). A hundred and ninety-seven outpatients referred with symptoms compatible with the diagnosis of OSA were studied. All participants had nocturnal pulse oximetry performed simultaneously with conventional polysomnography. Power density of heart rate obtained by nocturnal pulse oximetry was analysed using fast Fourier transformation of a Hamming-windowed signal. Recording test results were classified as abnormal (suspicion of OSA) in the presence of a peak in the periodogram between period boundaries 30-70 sec. A normal test result was defined as the absence of the 30-70 sec peak in the periodogram. The total area of the periodogram (S(TOT)), the area enclosed in the periodogram between the period boundaries 30-70 sec (S(30-70)), the area enclosed in the period boundaries 30-70 sec with respect to the total area of the periodogram (S) and the peak amplitude 30-70 sec (PA) were measured. The presence of a peak in the periodogram has a sensitivity of 81.3%, a specificity of 91.5% a positive predictive value of 89.1% and a negative predictive value of 85.1% for OSA diagnosis. The OSA patients were found to have higher values of S(TOT), S(30-70), S and PA than the non OSA patients. Receiver operating characteristics (ROC) curve was constructed at different thresholds of S(TOT), S(30-70) S and PA. For a PA threshold of 10(%)2, heart rate spectra analysis sensitivity for OSA was 58% and specificity was 92%. Furthermore, the positive and negative predictive values for diagnosis of OSA were 87 and 72% respectively. Apnoea hypopnea index (AHI) correlated significantly with S(TOT) (r=0.44; P<0.001), S(30-70) (r=0.59: P<0.001), S (r=0.58; P<0.001) and PA (r=0.58; P<0.001). According to our results, heart rate spectral analys s obtained by nocturnal pulse oximetry and identification of peak in the periodogram between period boundaries 30-70 sec could be useful as a diagnostic technique for OSA patients.