How can a milk protein selectively kill cancer cells? Mechanisms underlying lactoferrin-induced apoptosis

Lactoferrin (Lf) is an iron-binding protein abundant in milk that has been shown to exhibit anticancer activity. Since Lf is non-toxic to cancer cells (1) and is well tolerated in humans (2), this protein has a huge potential to be used in cancer therapy. However, the targets and mechanisms underlying its selective anticancer activity are poorly elucidated, which limits its clinical exploitation. The recruitment of the proton pump V-ATPase to the plasma membrane, where it mediates the acidification of the tumor microenvironment, is a recognized feature involved in the acquisition of a metastatic phenotype in different cancers, including breast cancer. Therefore, inhibitors of this pump have emerged as promising anticancer drugs. Here we show that bovine lactoferrin (bLf) preferentially inhibits cell proliferation and induces apoptosis in two highly metastatic breast cancer cell lines, which display a prominent localization of V-ATPase at the plasma membrane, but not in a lowly metastatic or a non-tumorigenic cell lines (3). We then characterized the mechanism underlying bLf-induced apoptosis and demonstrated that bLf selective cytotoxicity is caused by the inhibition of extracellular acidification rate and the ensuing intracellular acidification in the highly metastatic breast cancer cells. Accordingly, bLf, like the well-known proton pump inhibitors concanamycin A and bafilomycin A1, inhibits V-ATPase proton pumping and hydrolytic activities in sub-cellular fractions enriched in this proton pump. We recently also demonstrated that bLf preferentially induces apoptosis in other types of highly metastatic cancer cells other than breast (4). Altogether, our data demonstrated for the first time that bLf acts as a V-ATPase inhibitor and established a common mechanism of action of bLf against highly metastatic cancer cell exhibiting this proton pump at the plasma membrane. This study opens promising perspectives for the safer and more rational application of bLf in the therapy of these life-threatening cancers. 1. Gibbons JA et al. (2015) BMC Cancer doi: 10.1186/s12885-015-1441-4. 2. Hayes TG et al. (2010) Invest New Drugs doi: 10.1007/s10637-009-9233-9. 3. Pereira CS et al. (2016) Oncotarget doi: 10.18632/oncotarget.11394. 4. Guedes JP et al. (2018) Frontiers in Oncology doi.org/10.3389/fonc.2018.00200info:eu-repo/semantics/publishedVersio

Exploring a novel effect of lactoferrin on the plasma membrane towards the elucidation of the mechanisms of action: from yeast to human cells

Microbiotec'17 - Congress of Microbiology and Biotechnology 2017info:eu-repo/semantics/publishedVersio

Deficit irrigation in Mediterranean environment. What lessons have we learnt from grapevine studies ?

Libro de Actas - X Simposium Hispano Português de Relaciones Hidricas, 2010Deficit irrigation techniques, implying that water is supplied at levels below full crop evapotranspiration throughout the growing season or in specific phenological stages, such as regulated deficit irrigation (RDI) or partial root drying (PRD), emerged as potential strategies to increase water savings with marginal decreases of yield and likely positive impact on fruit quality. Understanding the physiological and molecular bases for plant responses to mild to moderate water deficits is of utmost importance to modulate the appropriate balance between vegetative and reproductive development, to improve crop water-use efficiency and to control fruit quality. It is acknowledged that the timing and intensity of the response to soil and atmospheric water deficits, namely in what concerns stomatal control, depends greatly on the genotype. This has profound implications in irrigation management, in particular the timing and amount of irrigation to optimize source-sink relationships and achieve optimal fruit quality in each variety. Mild water deficits also exert direct and/or indirect (via the light environment in the cluster zone) effects on berry development and composition. A current research challenge is determining how the environment, in particular water deficits, regulates genes and proteins of the various metabolic pathways responsible for berry composition and therefore for wine qualit

Deficit irrigation in Mediterranean vineyards - a tool to increase water use efficiency and to control grapevine and berry growth

IHC - IS Viti&Climate: Effect of Climate Change on Production and Quality of Grapevines and their Products, 28 th, 2012Water is increasingly scarce in Mediterranean Europe and irrigated agriculture is one of the largest and most inefficient users of this natural resource. Ecological topics such as the “water foot print” have become more relevant for the academy, consumers, governments and food industry. The wine sector needs solutions to improve its economical and environmental sustainability. Agronomical solutions, such as deficit irrigation (water supply below full crop evapotranspiration) have emerged as a tool for more efficient water use in irrigated viticulture and with likely positive effects on berry quality. Improving our understanding on the physiological and molecular basis of grapevine responses to water stress is an important task for research on irrigated viticulture. Better knowledge of the different genotypic responses (e.g., leaf gas exchange) to water stress can help to optimize crop/soil management and improve yield as well as berry quality traits under unfavourable climate conditions. Mild water deficits have direct and/or indirect (via the light environment in the cluster zone) effects on berry growth and composition. Another important challenge is to determine how soil water deficit regulate genes and proteins of the various metabolic pathways influencing berry composition and consequently wine quality

Grapevine under deficit irrigation: hints from physiological and molecular data

Background - A large proportion of vineyards are located in regions with seasonal drought (e.g. Mediterraneantype climates) where soil and atmospheric water deficits, together with high temperatures, exert large constraints on yield and quality. The increasing demand for vineyard irrigation requires an improvement in the efficiency of water use. Deficit irrigation has emerged as a potential strategy to allow crops to withstand mild water stress with little or no decreases of yield, and potentially a positive impact on fruit quality. Understanding the physiological and molecular bases of grapevine responses to mild to moderate water deficits is fundamental to optimize deficit irrigation management and identify the most suitable varieties to those conditions. Scope - How the whole plant acclimatizes to water scarcity and how short- and long-distance chemical and hydraulic signals intervene are reviewed. Chemical compounds synthesized in drying roots are shown to act as long-distance signals inducing leaf stomatal closure and/or restricting leaf growth. This explains why some plants endure soil drying without significant changes in shoot water status. The control of plant water potential by stomatal aperture via feed-forward mechanisms is associated with ‘isohydric’ behaviour in contrast to ‘anysohydric’ behaviour in which lower plant water potentials are attained. This review discusses differences in this respect between grapevines varieties and experimental conditions. Mild water deficits also exert direct and/or indirect (via the light environment around grape clusters) effects on berry development and composition; a higher content of skin-based constituents (e.g. tannins and anthocyanins) has generally being reported. Regulation under water deficit of genes and proteins of the various metabolic pathways responsible for berry composition and therefore wine quality are reviewed

Avaliação da incidência de Murcha Bacteriana em tomateiro sob cultivo protegido no Município de Iranduba-AM.

Este trabalho objetiva avaliar a incidência de murcha bacteriana em tomateiro plantado sucessivamente, em sistema de cultivo protegido, na região de Iranduba ? AM

Potencial produtivo de dois cultivares de tomate, plantados em sucessão ao milho, visando diminuir a incidência de Murcha Bacteriana.

Com a finalidade de indicação de inovações tecnológicas que possibilitem a produção desta hortaliça em grande escala, este trabalho objetiva avaliar o potencial produtivo e comercial de dois cultivares de tomate e técnicas de manejo visando diminuir a incidência de murcha bacteriana, em sistema de cultivo protegido, na região de Iranduba ? AM

Efeito da rotação de culturas sobre os índices produtivos de dois cultivares de tomate no município de Iranduba-AM.

O projeto visa avaliar o efeito da rotação de culturas sobre os índices produtivos de dois cultivares de tomate na redução da incidência de murcha bacteriana, na região de Iranduba - Amazonas

Lactoferrin perturbs lipid rafts and requires integrity of Pma1p-lipid rafts association to exert its antifungal activity against Saccharomyces cerevisiae

"Available online 07 January 2021"Lactoferrin (Lf) is a bioactive milk-derived protein with remarkable wide-spectrum antifungal activity. To deepen our understanding of the molecular mechanisms underlying Lf cytotoxicity, the role of plasma membrane ergosterol- and sphingolipid-rich lipid rafts and their association with the proton pump Pma1p was explored. Pma1p was previously identified as a Lf-binding protein. Results showed that bovine Lf (bLf) perturbs sterol-rich lipid rafts organization by inducing intracellular accumulation of ergosterol. Using yeast mutant strains lacking lipid rafts-associated proteins or enzymes involved in the synthesis of ergosterol and sphingolipids, we found that perturbations in the composition of these membrane domains increase resistance to bLf-induced yeast cell death. Also, when Pma1p-lipid rafts association is compromised in the Pma110 mutant and in the absence of the Pma1p-binding protein Ast1p, the bLf killing activity is impaired. Altogether, results showed that the perturbation of lipid rafts and the inhibition of both Pma1p and V-ATPase activities mediate the antifungal activity of bLf. Since it is suggested that the combination of conventional antifungals with lipid rafts-disrupting compounds is a powerful antifungal approach, our data will help to pave the way for the use of bLf alone or in combination for the treatment/eradication of clinically and agronomically relevant yeast pathogens/fungi.This work was supported by national funds through the Portuguese Foundation for Science and Technology (FCT I.P.) under the scope of the strategic funding of “Contrato-Programa” UIDB/04050/2020 and UIDB/ 04469/2020 unit; by the BioTecNorte operation (NORTE-01-0145- FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte; and by the Servicio para el Control de la Esterilización, Laboratorio de Microbiología Oral (CN-16-036). Cátia Santos-Pereira acknowledges the PhD fellowship PD/BD/128032/2016 funded by FCT under the scope of the doctoral programme in Applied and Environmental Microbiology (DP_AEM).info:eu-repo/semantics/publishedVersio

Deciphering the mechanisms underlying bovine milk lactoferrin anticancer activity using yeast and cancer cell lines as complementary models

Lactoferrin (Lf) is a milk derived iron-binding protein that exhibits a broad range of interesting biological activities, from which its anticancer and antifungal activities stand out. Our group has been elucidating the mechanisms and identifying the molecular targets underlying Lf anticancer/antifungal activities in order to improve its therapeutic efficacy and rational application. Indeed, we previously demonstrated that Lf triggers a mitochondrial and caspase-dependent regulated cell death in Saccharomyces cerevisiae (1). Moreover, we found that Lf selectively induces apoptosis in highly metastatic cell lines displaying the proton pump V-ATPase at the plasma membrane (2). However, much work is needed to further characterize Lf mechanisms of action. In the present work, we show how functional genomic approaches using yeast deletion mutants provided new insights on the activity of Lf against yeast that were then validated in human cancer cell lines. Results will be discussed in an integrated manner regarding their contribution towards understanding the molecular basis of Lf anticancer activity. In addition, this study highlights the great potential of yeast as a model to uncover mechanisms of action occurring in the more complex human cells. References (1) Acosta-Zaldívar M, Andrés MT, Rego A, Pereira CS, Fierro JF, Côrte-Real M. (2016) Human lactoferrin triggers a mitochondrial- and caspase-dependent regulated cell death in Saccharomyces cerevisiae. Apoptosis. 21(2):163-73. doi: 10.1007/s10495-015-1199-9. (2) Pereira CS, Guedes JP, Gonçalves M, Loureiro L, Castro L, Gerós H, Rodrigues LR, Côrte-Real M. (2016) Lactoferrin selectively triggers apoptosis in highly metastatic breast cancer cells through inhibition of plasmalemmal V-H+-ATPase. Oncotarget. 7(38):62144-62158. doi: 10.18632/oncotarget.11394.info:eu-repo/semantics/publishedVersio