Various tomato cultivars display contrasting morphological and molecular responses to a chronic heat stress

Climate change is one of the biggest threats that human society currently needs to face. Heat waves associated with global warming negatively affect plant growth and development and will increase in intensity and frequency in the coming years. Tomato is one of the most produced and consumed fruit in the world but remarkable yield losses occur every year due to the sensitivity of many cultivars to heat stress (HS). New insights into how tomato plants are responding to HS will contribute to the development of cultivars with high yields under harsh temperature conditions. In this study, the analysis of microsporogenesis and pollen germination rate of eleven tomato cultivars after exposure to a chronic HS revealed differences between genotypes. Pollen development was either delayed and/or desynchronized by HS depending on the cultivar considered. In addition, except for two, pollen germination was abolished by HS in all cultivars. The transcriptome of floral buds at two developmental stages (tetrad and pollen floral buds) of five cultivars revealed common and specific molecular responses implemented by tomato cultivars to cope with chronic HS. These data provide valuable insights into the diversity of the genetic response of floral buds from different cultivars to HS and may contribute to the development of future climate resilient tomato varieties.

Targeting FOXP3 Tumor-Intrinsic Effects Using Adenoviral Vectors in Experimental Breast Cancer

The regulatory T cell master transcription factor, Forkhead box P3 (Foxp3), has been detected in cancer cells; however, its role in breast tumor pathogenesis remains controversial. Here we assessed Foxp3 tumor intrinsic effects in experimental breast cancer using a Foxp3 binder peptide (P60) that impairs Foxp3 nuclear translocation. Cisplatin upregulated Foxp3 expression in HER2+ and triple-negative breast cancer (TNBC) cells. Foxp3 inhibition with P60 enhanced chemosensitivity and reduced cell survival and migration in human and murine breast tumor cells. We also developed an adenoviral vector encoding P60 (Ad.P60) that efficiently transduced breast tumor cells, reduced cell viability and migration, and improved the cytotoxic response to cisplatin. Conditioned medium from transduced breast tumor cells contained lower levels of IL-10 and improved the activation of splenic lymphocytes. Intratumoral administration of Ad.P60 in breast-tumor-bearing mice significantly reduced tumor infiltration of Tregs, delayed tumor growth, and inhibited the development of spontaneous lung metastases. Our results suggest that Foxp3 exerts protumoral intrinsic effects in breast cancer cells and that gene-therapy-mediated blockade of Foxp3 could constitute a therapeutic strategy to improve the response of these tumors to standard treatment.

Mitochondrial Peptide Humanin Facilitates Chemoresistance in Glioblastoma Cells

Humanin (HN) is a mitochondrial-derived peptide with robust cytoprotective effects in many cell types. Although the administration of HN analogs has been proposed to treat degenerative diseases, its role in the pathogenesis of cancer is poorly understood. Here, we evaluated whether HN affects the chemosensitivity of glioblastoma (GBM) cells. We found that chemotherapy upregulated HN expression in GBM cell lines and primary cultures derived from GBM biopsies. An HN analog (HNGF6A) boosted chemoresistance, increased the migration of GBM cells and improved their capacity to induce endothelial cell migration and proliferation. Chemotherapy also upregulated FPR2 expression, an HN membrane-bound receptor, and the HNGF6A cytoprotective effects were inhibited by an FPR2 receptor antagonist (WRW4). These effects were observed in glioma cells with heterogeneous genetic backgrounds, i.e., glioma cells with wild-type (wtIDH) and mutated (mIDH) isocitrate dehydrogenase. HN silencing using a baculoviral vector that encodes for a specific shRNA for HN (BV.shHN) reduced chemoresistance, and impaired the migration and proangiogenic capacity of GBM cells. Taken together, our findings suggest that HN boosts the hallmark characteristics of GBM, i.e., chemoresistance, migration and endothelial cell proliferation. Thus, strategies that inhibit the HN/FPR2 pathway may improve the response of GBM to standard therapy.

Evaluation of Baculoviruses as Gene Therapy Vectors for Brain Cancer

We aimed to assess the potential of baculoviral vectors (BV) for brain cancer gene therapy. We compared them with adenoviral vectors (AdV), which are used in neuro-oncology, but for which there is pre-existing immunity. We constructed BVs and AdVs encoding fluorescent reporter proteins and evaluated their transduction efficiency in glioma cells and astrocytes. Naïve and glioma-bearing mice were intracranially injected with BVs to assess transduction and neuropathology. Transgene expression was also assessed in the brain of BV-preimmunized mice. While the expression of BVs was weaker than AdVs in murine and human glioma cell lines, BV-mediated transgene expression in patient-derived glioma cells was similar to AdV-mediated transduction and showed strong correlation with clathrin expression, a protein that interacts with the baculovirus glycoprotein GP64, mediating BV endocytosis. BVs efficiently transduced normal and neoplastic astrocytes in vivo, without apparent neurotoxicity. BV-mediated transgene expression was stable for at least 21 days in the brain of naïve mice, but it was significantly reduced after 7 days in mice systemically preimmunized with BVs. Our findings indicate that BVs efficiently transduce glioma cells and astrocytes without apparent neurotoxicity. Since humans do not present pre-existing immunity against BVs, these vectors may constitute a valuable tool for the delivery of therapeutic genes into the brain.

Development of immunotherapy for high-grade gliomas: Overcoming the immunosuppressive tumor microenvironment

The preclinical and clinical development of novel immunotherapies for the treatment of central nervous system (CNS) tumors is advancing at a rapid pace. High-grade gliomas (HGG) are aggressive tumors with poor prognoses in both adult and pediatric patients, and innovative and effective therapies are greatly needed. The use of cytotoxic chemotherapies has marginally improved survival in some HGG patient populations. Although several challenges exist for the successful development of immunotherapies for CNS tumors, recent insights into the genetic alterations that define the pathogenesis of HGG and their direct effects on the tumor microenvironment (TME) may allow for a more refined and targeted therapeutic approach. This review will focus on the TME in HGG, the genetic drivers frequently found in these tumors and their effect on the TME, the development of immunotherapy for HGG, and the practical challenges in clinical trials employing immunotherapy for HGG. Herein, we will discuss broadly the TME and immunotherapy development in HGG, with a specific focus on glioblastoma multiforme (GBM) as well as additional discussion in the context of the pediatric HGG diagnoses of diffuse midline glioma (DMG) and diffuse hemispheric glioma (DHG).

Potential of IDH mutations as immunotherapeutic targets in gliomas: a review and meta-analysis

INTRODUCTION

Gliomas are stratified by the presence of a hotspot mutation in the enzyme isocitrate dehydrogenase genes (IDH1/2). While mutated IDH (mIDH) correlates with better prognosis, the role of this mutation in antitumor immunity and the response to immunotherapy is not completely understood. Understanding the relationship between the genetic features of these tumors and the tumor immune microenvironment (TIME) may help to develop appropriate therapeutic strategies.

AREAS COVERED

In this review we discussed the available literature related to the potential role of IDH mutations as an immunotherapeutic target in gliomas and profiled the immune transcriptome of glioma biopsies. We aimed to shed light on the role of mIDH on the immunological landscape of the different subtypes of gliomas, taking into account the most recent WHO classification of tumors of the central nervous system (CNS). We also discussed different immunotherapeutic approaches to target mIDH tumors and to overcome their immunosuppressive microenvironment.

EXPERT OPINION

Data presented here indicates that the TIME not only differs in association with IDH mutation status, but also within glioma subtypes, suggesting that the cellular context affects the overall effect of this genetic lesion. Thus, specific therapeutic combinations may help patients diagnosed with different glioma subtypes.

Physical activity trajectories are associated with the risk of all-cause and cardiovascular disease mortality in patients with coronary heart disease. A systematic review and meta-analysis

Background

Current guidelines recommend that adults with chronic health conditions should engage in regular physical activity (PA), and avoid inactivity. Yet, the exact role of PA trajectories in the mortality risk of patients with coronary heart disease (CHD) remains unclear.

Purpose

We aimed to perform a systematic review and meta-analysis on the association of longitudinal trajectories of PA with all-cause and cardiovascular disease (CVD) mortality in patients with CHD.

Methods

We performed a systematic review and meta-analysis based on PRISMA statement. Six electronic databases were searched for cohort studies that analysed the association of PA trajectories (inactive over time, active over time, increased activity over time, and decreased activity over time) with the risk of all-cause and CVD mortality in patients with CHD. Study quality was evaluated by the Newcastle Ottawa scale. We used the inverse variance weighted method to combine summary measures using random-effects models to minimize the effect of between-study heterogeneity. The study is registered in PROSPERO.

Results

We meta-analyzed nine longitudinal cohorts involving 33,576 patients (25010 acute CHD, 8566 chronic CHD, mean age 62.5 years, 34% women, median follow-up duration 7.2 years), according to four PA trajectories. All studies assessed PA through validated questionnaires. The definitions of activity and inactivity at baseline and follow-ups were in agreement with current PA guidelines. Trajectories were calculated based on comparison of activity status at baseline and follow-up. All the studies defined increased activity over time as moving from the inactive to the active category, and decreased activity over time as moving from the active to the inactive category. Compared to patients remaining inactive over time, the lowest risk of all-cause and CVD mortality was observed in patients remaining active over time (HR [95% CI]: 0.50 [0.39–0.63] and 0.48 [0.35–0.68], respectively), followed by patients who increased their PA over time (HR [95% CI]:0.55 [0.44–0.7] and 0.63 [0.51–0.78], respectively), and patients who decreased activity over time (HR [95% CI]: 0.80 [0.64–0.99] and 0.91 [0.67–1.24], respectively). These results were consistent both in the acute and chronic CHD settings. The overall risk of bias was low, and no evidence of publication bias was observed. Multiple sensitivity analyses provided consistent results.

Conclusions

In patients with CHD, the risk of all-cause and CVD mortality is progressively reduced from being inactive over time, to decreased activity over time, to increased activity over time, to being active over time. These findings highlight the benefits of adopting a more physically active lifestyle in patients with chronic and acute CHD, independent of previous PA levels. Future studies should clarify the complex interactions between motivations and disease severity as potential drivers for PA trajectories

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Bern

Genetic Alterations in Gliomas Remodel the Tumor Immune Microenvironment and Impact Immune-Mediated Therapies

High grade gliomas are malignant brain tumors that arise in the central nervous system, in patients of all ages. Currently, the standard of care, entailing surgery and chemo radiation, exhibits a survival rate of 14-17 months. Thus, there is an urgent need to develop new therapeutic strategies for these malignant brain tumors. Currently, immunotherapies represent an appealing approach to treat malignant gliomas, as the pre-clinical data has been encouraging. However, the translation of the discoveries from the bench to the bedside has not been as successful as with other types of cancer, and no long-lasting clinical benefits have been observed for glioma patients treated with immune-mediated therapies so far. This review aims to discuss our current knowledge about gliomas, their molecular particularities and the impact on the tumor immune microenvironment. Also, we discuss several murine models used to study these therapies pre-clinically and how the model selection can impact the outcomes of the approaches to be tested. Finally, we present different immunotherapy strategies being employed in clinical trials for glioma and the newest developments intended to harness the immune system against these incurable brain tumors.

The role of the prolactin receptor pathway in the pathogenesis of glioblastoma: what do we know so far?

Introduction: Prolactin (PRL) and its receptor (PRLR) have been associated with the development of hormone-dependent tumors and have been detected in glioblastoma (GBM) biopsies. GBM is the most common and aggressive primary brain tumor in adults and the prognosis for patients is dismal; hence researchers are exploring the PRLR pathway as a therapeutic target in this disease. Areas covered: This paper explores the effects of PRLR activation on the biology of GBM, the correlation between PRL and PRLR expression and GBM progression and survival in male and female patients. Finally, we discuss how a better understanding of the PRLR pathway may allow the development of novel treatments for GBM. Expert opinion: We propose PRL and PRLR as potential prognosis biomarkers and therapeutic targets in GBM. Local administration of PRLR inhibitors using gene therapy may offer a beneficial strategy for targeting GBM cells disseminated in the non-neoplastic brain; however, efficacy and safety require careful and extensive evaluation. The data depicted herein underline the need to (i) improve our understanding of sexual dimorphism in GBM, and (ii) develop accurate preclinical models that take into consideration different hormonal contexts, specific genetic alterations, and tumor grades.

Prolactin and its receptor as therapeutic targets in glioblastoma multiforme

Although prolactin (PRL) and its receptor (PRLR) have been detected in glioblastoma multiforme (GBM), their role in its pathogenesis remains unclear. Our aim was to explore their contribution in GBM pathogenesis. We detected PRL and PRLR in all GBM cell lines tested. PRLR activation or overexpression using plasmid transfection increased proliferation, viability, clonogenicity, chemoresistance and matrix metalloproteinase activity in GBM cells, while PRLR antagonist ∆1–9-G129R-hPRL reduced their proliferation, viability, chemoresistance and migration. Meta-analysis of transcriptomic data indicated that PRLR was expressed in all grade II-III glioma (GII-III) and GBM samples. PRL was upregulated in GBM biopsies when compared to GII-III. While in the general population tumour PRL/PRLR expression did not correlate with patient survival, biological sex-stratified analyses revealed that male patients with PRL⁺/PRLR^HIGH GBM performed worse than PRL⁺/PRLR^LOW GBM. In contrast, all male PRL⁺/PRLR^HIGH GII-III patients were alive whereas only 30% of PRL⁺/PRLR^LOW GII-III patients survived after 100 months. Our study suggests that PRLR may be involved in GBM pathogenesis and could constitute a therapeutic target for its treatment. Our findings also support the notion that sexual dimorphism should be taken into account to improve the care of GBM patients.

Interaction of Cu(i) with the Met-X3-Met motif of alpha-synuclein: binding ligands, affinity and structural features

The identity of the Cu(i) binding ligands at Met-X3-Met site of AcαS and its role into the affinity and structural properties of the interaction were elucidated by NMR spectroscopy. We provide evidence that the source of ligands for Cu(i) binding to the Met-X3-Met site comes from the N-terminal acetyl group and the Met-1, Asp-2 and Met-5 residues. From the study of site-directed mutants and synthetic peptide models of αS we demonstrated the critical role played by Met-1 and Met-5 residues on the binding affinity of the Cu(i) complex, acting as the main metal anchoring residues. While having a more modest impact in the affinity features of Cu(i) binding, as compared to the Met residues, the N-terminal acetyl group and Asp-2 are important in promoting local helical conformations, contributing to the stabilization of these structures by favoring Cu(i) binding.

In vitro inactivation of Mycobacterium avium subsp. paratuberculosis (MAP) by use of copper ions

Background

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis, a contagious infectious disease that affects domestic and wild ruminants causing chronic inflammation of the intestine. MAP has proven to be very resistant to both physical and chemical processes, making it difficult to control this pathogen. Based on the recognized antimicrobial properties of copper, the objective of this study was to evaluate the effectiveness of copper ions to reduce MAP numbers and/or MAP viability in a fluid matrix. Besides, methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli were used as controls of the effectiveness of copper ions. MAP-spiked PBS was subjected to copper ions treatment at 24 V for 5 min and the PBS suspensions were sampled before and after treatment. MAP viability and quantification were determined using three complementary techniques: a phage amplification assay, MGIT culture and qPCR.

Results

Moderate numbers (10³ CFU ml⁻¹) of the two control bacteria were completely eliminated by treatment with copper ions. For MAP, copper ions treatment reduced both the viability and numbers of this pathogen. Phage assay information quickly showed that copper ions (24 V for 5 min) resulted in a significant reduction in viable MAP. MGIT culture results over time showed statistically significant differences in time-to-detection (TTD) values between PRE and POST treatment. MAP genome equivalent estimates for PBS suspensions indicated that MAP numbers were lower in samples POST-treatment with copper ions than PRE-treatment.

Conclusions

The use of copper ions resulted in a significant reduction of MAP in a liquid matrix, although some MAP survival on some occasions was observed.

Induced ovule-to-flower switch by interfering with SlIMA activity in tomato

The INHIBITOR OF MERISTEM ACTIVITY in tomato (SlIMA) and MINI ZINC FINGER 2 in Arabidopsis (AtMIF2), two members of the MINI ZINC FINGER family (MIF), are involved in the regulation of flower and ovule development. MIF proteins possess a unique non-canonical zinc-finger domain that confers the capacity to interact with other protein partners. The characterization of SlIMA and AtMIF2 gain- and loss-of-function transgenic lines in Solanum lycopersicum and Arabidopsis thaliana respectively, allowed the demonstration of their conserved functional role in the termination of floral stem cell maintenance. During early floral development, the expression of SlIMA and AtMIF2 is induced by the MADS-Box transcription factor AGAMOUS (AG). Then, SlIMA or AtMIF2 protein recruits the C₂H₂ zinc finger KNUCKLES (KNU), in a transcriptional repressor complex together with TOPLESS (TPL) and HISTONE DEACETYLASE19 (HDA19). This complex binds to the WUSCHEL (WUS) locus leading to its repression. To further characterize the role of these interactions in flower development, we have investigated the effects of a dominant negative form of SlIMA, SlIMA^ch that leads to spectacular phenotypes, including ovule conversion into a floral meristem.

Posttransplant oxygen inhalation improves the outcome of subcutaneous islet transplantation: A promising clinical alternative to the conventional intrahepatic site

Subcutaneous tissue is a promising site for islet transplantation, due to its large area and accessibility, which allows minimally invasive procedures for transplantation, graft monitoring, and removal of malignancies as needed. However, relative to the conventional intrahepatic transplantation site, the subcutaneous site requires a large number of islets to achieve engraftment success and diabetes reversal, due to hypoxia and low vascularity. We report that the efficiency of subcutaneous islet transplantation in a Lewis rat model is significantly improved by treating recipients with inhaled 50% oxygen, in conjunction with prevascularization of the graft bed by agarose-basic fibroblast growth factor. Administration of 50% oxygen increased oxygen tension in the subcutaneous site to 140 mm Hg, compared to 45 mm Hg under ambient air. In vitro, islets cultured under 140 mm Hg oxygen showed reduced central necrosis and increased insulin release, compared to those maintained in 45 mm Hg oxygen. Six hundred syngeneic islets subcutaneously transplanted into the prevascularized graft bed reversed diabetes when combined with postoperative 50% oxygen inhalation for 3 days, a number comparable to that required for intrahepatic transplantation; in the absence of oxygen treatment, diabetes was not reversed. Thus, we show oxygen inhalation to be a simple and promising approach to successfully establishing subcutaneous islet transplantation.

Relevance of small GTPase Rac1 pathway in drug and radio-resistance mechanisms: Opportunities in cancer therapeutics

Rac1 GTPase signaling pathway has a critical role in the regulation of a plethora of cellular functions governing cancer cell behavior. Recently, it has been shown a critical role of Rac1 in the emergence of resistance mechanisms to cancer therapy. This review describes the current knowledge regarding Rac1 pathway deregulation and its association with chemoresistance, radioresistance, resistance to targeted therapies and immune evasion. This supports the idea that interfering Rac1 signaling pathway could be an interesting approach to tackle cancer resistance.

Pharmacological Rac1 inhibitors with selective apoptotic activity in human acute leukemic cell lines

Rac1 GTPase has long been recognized as a critical regulatory protein in different cellular and molecular processes involved in cancer progression, including acute myeloid leukemia. Here we show the antitumoral activity of ZINC69391 and 1A-116, two chemically-related Rac1 pharmacological inhibitors, on a panel of four leukemic cell lines representing different levels of maturation. Importantly, we show that the main mechanism involved in the antitumoral effect triggered by the Rac1 inhibitors comprises the induction of the mitochondrial or intrinsic apoptotic pathway. Interestingly, Rac1 inhibition selectively induced apoptosis on patient-derived leukemia cells but not on normal mononuclear cells. These results show the potential therapeutic benefits of targeting Rac1 pathway in hematopoietic malignancies.

Rho GTPases as therapeutic targets in cancer (Review)

Rho GTPases are key molecular switches controlling the transduction of external signals to cytoplasmic and nuclear effectors. In the last few years, the development of genetic and pharmacological tools has allowed a more precise definition of the specific roles of Rho GTPases in cancer. The aim of the present review is to describe the cellular functions regulated by these proteins with focus in deregulated signals present in malignant tumors. Finally, we describe the state of the art in search of different experimental therapeutic strategies with Rho GTPases as molecular targets.

Peptide Agonists of Vasopressin V2 Receptor Reduce Expression of Neuroendocrine Markers and Tumor Growth in Human Lung and Prostate Tumor Cells

Neuroendocrine tumors (NETs) comprise a heterogeneous group of malignancies that express neuropeptides as synaptophysin, chromogranin A (CgA), and specific neuronal enolase (NSE), among others. Vasopressin (AVP) is a neuropeptide with an endocrine, paracrine, and autocrine effect in normal and pathological tissues. AVP receptors are present in human lung, breast, pancreatic, colorectal, and gastrointestinal tumors. While AVP V1 receptors are associated with stimulation of cellular proliferation, AVP V2 receptor (V2r) is related to antiproliferative effects. Desmopressin (dDAVP) is a synthetic analog of AVP that acts as a selective agonist for the V2r, which shows antitumor properties in breast and colorectal cancer models. Recently, we developed a derivative of dDAVP named [V⁴Q⁵]dDAVP, which presents higher antitumor effects in a breast cancer model compared to the parental compound. The goal of present work was to explore the antitumor properties of the V2r agonist dDAVP and its novel analog [V⁴Q⁵]dDAVP on aggressive human lung (NCI-H82) and prostate cancer (PC-3) cell lines with neuroendocrine (NE) characteristics. We study the presence of specific NE markers (CgA and NSE) and V2r expression in NCI-H82 and PC-3. Both cell lines express high levels of NE markers NSE and CgA but then incubation with dDAVP diminished expression levels of both markers. DDAVP and [V⁴Q⁵]dDAVP significantly reduced proliferation, doubling time, and migration in both tumor cell cultures. [V⁴Q⁵]dDAVP analog showed a higher cytostatic effect than dDAVP, on cellular proliferation in the NCI-H82 cell line. Silencing of V2r using small interfering RNA significantly attenuated the inhibitory effects of [V⁴Q⁵]dDAVP on NCI-H82 cell proliferation. We, preliminarily, explored the in vivo effect of dDAVP and [V⁴Q⁵]dDAVP on NCI-H82 small cell lung cancer xenografts. Treated tumors (0.3 μg kg^-1, thrice a week) grew slower in comparison to vehicle-treated animals. In this work, we demonstrated that the specific agonists of V2r, dDAVP, and [V⁴Q⁵]dDAVP displays antitumor capacity on different human models of lung and prostate cancers with NE features, showing their potential therapeutic benefits in the treatment of these aggressive tumors.

Prognostic severity scores for patients with COPD exacerbations attending emergency departments

SETTING

Reported predictors of the adverse evolution of patients with chronic obstructive pulmonary disease exacerbations (eCOPD) are various and inconsistent in the bibliography.

OBJECTIVE

To develop clinical prediction rules for short-term outcomes in eCOPD patients attending an emergency department (ED).

DESIGN

Prospective cohort study of patients with an eCOPD. Short-term outcomes were admission to an intensive care unit (ICU), admission to an intermediate respiratory care unit (IRCU) and death in these groups. Multivariate logistic regression models were developed for each of the outcomes.

RESULTS

Predictors of ICU or IRCU admission were use of long-term home oxygen therapy (LT-HOT) or non-invasive mechanical ventilation (NIMV), elevated PCO2 and decreased pH upon ED arrival (area under the curve [AUC] 0.87 in the derivation sample; 0.89 in the validation sample). Among those admitted to an ICU or IRCU, predictors of death were increased age, use at home of LT-HOT or NIMV, use of inspiratory accessory muscles upon ED arrival and altered Glasgow Coma Scale (<15 points) (AUC 0.78).

CONCLUSIONS

Three clinical predictors available in the ED can be used to create a simple score to predict the need for intensive treatment among eCOPD patients. Such a score can be a tool for clinical practice.

Preclinical development of novel Rac1-GEF signaling inhibitors using a rational design approach in highly aggressive breast cancer cell lines

Rho GTPases play a key role in the regulation of multiple essential cellular processes, including actin dynamics, gene transcription and cell cycle progression. Aberrant activation of Rac1, a member of Rho family of small GTPases, is associated with tumorigenesis, cancer progression, invasion and metastasis. Particularly, Rac1 is overexpressed and hyperactivated in highly aggressive breast cancer. Thus, Rac1 appears to be a promising and relevant target for the development of novel anticancer drugs. We identified the novel Rac1 inhibitor ZINC69391 through a docking-based virtual library screening targeting Rac1 activation by GEFs. This compound was able to block Rac1 interaction with its GEF Tiam1, prevented EGF-induced Rac1 activation and inhibited cell proliferation, cell migration and cell cycle progression in highly aggressive breast cancer cell lines. Moreover, ZINC69391 showed an in vivo antimetastatic effect in a syngeneic animal model. We further developed the novel analog 1A-116 by rational design and showed to be specific and more potent than the parental compound in vitro and interfered Rac1-P-Rex1 interaction. We also showed an enhanced in vivo potency of 1A-116 analog. These results show that we have developed novel Rac1 inhibitors that may be used as a novel anticancer therapy.

Sage (Salvia officinalis) and fennel (Foeniculum vulgare) improve cryopreserved boar epididymal semen quality study

The aim of this study was to evaluate the effect of fennel and sage extracts and the influence of the egg yolk source (fresh or pasteurized) on the success of freezing boar epididymal spermatozoa. In experiment 1, epididymal sperm was recovered by flushing and cryopreserved in a lactose-egg yolk solution supplemented with various concentrations (10, 5 and 2.5 g/L) of sage or fennel. Sperm quality was evaluated (motility, viability, HOST and acrosome integrity) at 0 h and 2 h after thawing. Fennel 10 g/L and sage 5 g/L and control (no extracts) were selected for experiment 2 which also compared fresh or pasteurized egg yolk in the freezing extender and measured DNA integrity of the frozen sperm. Results showed that the interaction between fennel and sage antioxidants with fresh egg yolk significantly improved post thaw sperm quality and protected boar epididymal spermatozoa from cryopreservation damage as a result of oxidative stress.

Proapoptotic and antiinvasive activity of Rac1 small molecule inhibitors on malignant glioma cells

Malignant gliomas are characterized by an intrinsic ability to invade diffusely throughout the normal brain tissue. This feature contributes mainly to the failure of existing therapies. Deregulation of small GTPases signaling, in particular Rac1 activity, plays a key role in the invasive phenotype of gliomas. Here we report the effect of ZINC69391, a specific Rac1 inhibitor developed by our group, on human glioma cell lines LN229 and U-87 MG. ZINC69391 is able to interfere with the interaction of Rac1 with Dock180, a relevant Rac1 activator in glioma invasion, and to reduce Rac1-GTP levels. The kinase Pak1, a downstream effector of Dock180-Rac1 signaling, was also downregulated upon ZINC69391 treatment. ZINC69391 reduced cell proliferation, arrested cells in G1 phase, and triggered apoptosis in glioma cells. Importantly, ZINC69391 dramatically affected cell migration and invasion in vitro, interfering with actin cytoskeleton dynamics. We also evaluated the effect of analog 1A-116, a compound derived from ZINC69391 structure. 1A-116 showed an improved antiproliferative and antiinvasive activity on glioma cells. These findings encourage further preclinical testing in clinically relevant animal models.

Relationship of sociodemographic variables with outcomes after cataract surgery

PURPOSE

The objective of this study is to analyse the relationship between sociodemographic characteristics of patients undergoing cataract extraction and their outcomes.

METHODS

The method comprised a prospective cohort study of patients recruited from 17 hospitals of different areas of Spain. Data gathered before surgery included sociodemographic variables, visual acuity, and visual function (using the Visual Function Index-14). After surgery, we assessed visual acuity and visual function at 6 weeks and at 3 months, respectively. Multivariate multilevel analysis was performed to assess the relationship of sociodemographic variables with changes in visual acuity and function, analysing whether improvements surpassed the minimal clinically important differences (MCIDs).

RESULTS

Multivariate analysis showed that for visual acuity, (i) older men had a lower odds ratio (OR) of surpassing the MCID (OR: 65-75 years, 0.64; >75 years, 0.51); (ii) those with primary (1.65) or secondary (1.41) education had higher ORs than those with no formal education; and (iii) those living in a residential home had a lower OR than men living alone (0.36). In women, we found that the higher the educational level, the greater the improvement in visual acuity (primary, 1.41; secondary, 1.76), whereas socially dependent women (0.70) were less likely to exceed the MCID. With regards to predictors related to achievement of an MCID in visual function, only dependency was associated with more improvement in men (OR: 1.39), whereas in women the educational level was the only predictor (primary: 0.72; secondary: 0.61).

CONCLUSIONS

This study found that patients with certain sociodemographic characteristics were less likely to experience an MCID in visual acuity or visual function after cataract surgery.

Abstract LB-305: Novel Rac1-GEF inhibitors as anticancer agents for aggressive tumors

Small GTPases of the Rho family, including Rac1, regulate fundamental cellular processes like actin cytoskeleton reorganization, cell migration and cell cycle progression. Rac1 has been associated with transformation, tumor progression and tumor cell migration in different type of cancers, including aggressive breast cancer and glioma. These proteins cycle between an active, GTP-bound state and an inactive, GDP-bound state. This cycle is highly regulated by many regulatory proteins, including activators such as guanine nucleotide exchange factors (GEFs).

We searched for Rac1 inhibitors able to interfere Rac1-GEF interaction using a docking-based virtual library screening approach. We selected ZINC69391 compound. This small-molecule was able to interfere Rac-Tiam1 and Rac-DOCK180 interaction in vitro and reduced Rac1-GTP intracellular levels but had no effect on the closely related Cdc42 GTPase. ZINC69391 also affected the activation of Pak1, one important Rac1 effector. This compound reduced cell migration, inhibited cell proliferation and arrested cell cycle progression in breast cancer cells and glioma cells. We also evaluated this compound in vivo and ZINC69391 was able to reduce 60% lung colonization in a breast cancer experimental metastasis model. We further evaluated novel analogs looking for more potent and specific Rac1 inhibitors. We synthesized a group of novel disubstituted guanidines and we screened these analogs in vitro. One of them, 1A-116 analog, showed to be more potent than the parental compound, reducing cancer cell proliferation and Rac1 activation at the low micromolar range. These data further confirm Rac1 GTPase as a valuable molecular target for anti-cancer therapies and drug development in breast cancer and glioma, where Rac1 presents a relevant role.

Citation Format: Georgina A. Cardama, Nazareno Gonzalez, Maria Julieta Comin, Adrian G. Turjanski, Daniel Fernando Alonso, Daniel Eduardo Gomez, Pablo Lorenzano Menna. Novel Rac1-GEF inhibitors as anticancer agents for aggressive tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-305. doi:10.1158/1538-7445.AM2013-LB-305

Surgical strategies for aneurysms deemed unclippable and uncoilable

Although most cerebral aneurysms can nowadays be successfully treated either by standard clipping or sole coiling, a subset of aneurysms may not be amenable to standard clipping or coiling and require alternative treatment options. Surgical options, other than clipping and/or endovascular options other than sole coiling, may be the optimal treatment plan for some complex aneurysms. Surgical strategies for such complex aneurysms include parent artery occlusion, revascularization procedures and flow redirection. In this article, we review which factors are predictive of failure of conventional aneurysm treatment options; summarize key information needed to orient treatment decision; and discuss surgical options for unclippable and uncoilable aneurysms.