Study of quercetin and fisetin synergistic effect on breast cancer and potentially involved signaling pathways

Naturally-derived drugs have drawn much attention in recent decades. Efficiency, lower toxicity, and economic reasons are some of their advantages that justify this broad range of administration for different diseases, including cancer. If we can find a specific combination that boosts the effects of their single therapy, leading to synergism effect, increased efficiency, and decreased toxicity, they can act even better. Quercetin and fisetin, two well-known flavonoids, have been used to fight against various cancers. In this study, we investigated their possible synergism quercetin and fisetin on MCF7, MDA-MB-231, BT549, T47D, and 4T1 breast cancer cell lines. Then the optimum combined dose was used to study their impacts on wound healing abilities and clonogenic properties. The real-time qPCR was used to study the expression of their validated downstream effectors in predicted pathways. A significant synergism effect (p < .01, combination index: <1) was observed for all cell lines. Combination therapy was significantly more effective in colony formation (p < .0001) and wound healing assays (p < .001) compared to single therapies. The expression level of potential effectors was also showed a greater change. In vivo study confirmed the in vitro results and showed how significantly (p < .001) their synergism promotes their singular function in inhibiting cancer progression. The breast cancer mouse models receiving combined therapy lived longer with higher average body weight and smaller tumor sizes. These results exhibit that quercetin and fisetin inhibit cancer cell proliferation, migration and colony formation synergistically, and matrix metalloproteinase signaling and apoptotic pathways are relatively responsible for inhibitory activities.     

Establishment of regional differences in brush border enzymatic activities during the development of fetal mouse small intestine

Summary In order to study the establishment of regional differences in brush border enzymic activities during the development of fetal mouse small intestine we have followed (1) the differentiation of microvilli by morphometry, and (2) the developmental pattern of three brush border enzymes (lactase, glucoamylase and alkaline phosphatase). From day 16 to day 19 of gestation, the height of duodenal microvilli increases 2.4 times on the absorptive cells located near the tip of the villi. During the same period in the upper half of the duodenal villi, the number of microvilli per square m rises by a factor of 2.4 and the microvillous surface area increases by a factor of 5.2. The differentiation of ileal microvilli follows a similar pattern but they are always shorter and less numerous than those of the duodenum. Lactase activity appears at 18 days of gestation; the other two brush border enzymes are first detected at 16 days of gestation. Afterwards all three enzyme activities increase rapidly and a decreasing gradient of activity is established from the proximal to the distal segment of the small intestine. Hence, the structural development of the microvilli and the appearance of brush border enzyme activities occur simultaneously and a proximo-distal gradient is already established at 16 days of gestation.Supported by MRC of Canada research grant MA-6069Mr. D. Malka was supported by a studentship from the F.C.A.C.Dr. D. Ménard is a chercheur boursier du Conseil de la Recherche en Santé du Québec     

Effect of clofibrate on the small intestine of fetal mice

Summary Pregnant Swiss ICR mice were injected with clofibrate at different dosages and time intervals, and embryos were removed either at 17 or 18 days of gestation. In embryos sacrificed at 17 days the level of intestinal catalase activity of the proximal and distal halves in the treated groups is identical in any case to that of the controls. In embryos sacrificed at 18 days, the rise in the level of catalase activity in the proximal half of the small intestine in treated groups is dose dependent up to a certain limit: with repeated injections the increase reaches a plateau. The distal halves of treated groups are much less responsive and an increase in catalase activity was noted only with repeated injections. In untreated embryos circular DAB-positive microperoxisomes (200 nm in diameter) and tubular structures (100 nm in thickness) are seen in the duodenum at 18 days of gestation. At the same stage, only circular microperoxisomes are identified in the ileum.After clofibrate treatment circular and tubular microperoxisomes are observed in the ileum also. It is concluded that clofibrate induces a rise in catalase activity in the embryo, only after 17 days of gestation. These observations are discussed in relation to the biogenesis of microperoxisome.Supported by Grant No. MA-6069 from the Medical Research Council of CanadaMr. D. Malka was supported by a studentship from the FCAC of the province of QuebecDr. D. Ménard is a Chercheur boursier du Conseil de la Recherche en Santé du Québec     

Flexural and Dynamic Mechanical Properties of Alkali-Treated Coir/Pineapple Leaf Fibres Reinforced Polylactic Acid Hybrid Biocomposites

Polylactic acid(PLA)possesses good mechanical and biodegradability properties which make it a suitable material for polymer composites whereas brittleness and high costs limit its utilization in various applications.The reinforcement of natural fibres with biopolymers has been formed to be an efficient technique to develop composites having the ability to be fully biodegradable.This study concerns with the incorporation of various percentages of untreated and alkali-treated Coir Fibres(CF)and pineapple leaf fibres(PALF)in PLA biocomposites and characterizations of flexural,morphological and dynamic mechanical properties.Flexural properties showed that the treated C1P1 hybrid composites(C1P1A)displayed highest flexural strength(35.81 MPa)and modulus(5.28 GPa)among all hybrid biocomposites.Scanning Electron Micros-copy(SEM)revealed a behaviour of fibre-matrix adhesion in untreated treated biocomposites.SEM observation revealed good dispersion of the fillers in PLA.Dynamic mechanical analysis revealed that C1P1A showed highest glass transition temperature(Tg)and storage modulus(E')while untreated C3P7 displayed the least Tg and E'.Overall findings showed that alkali-treated hybrid biocomposites(CF/PALF/PLA)especially C1P1A have improved flexural properties,dynamic and morphological properties over untreated biocomposites.Success of these findings will provide attracting consideration of these hybrid biocomposites for various lightweight uses in a broad selection of industrial applications such as biomedical sectors,automobile,construction,electronics equipment,and hardware tools.     

Predicting potentially pathogenic effects of hRPE65 missense mutations: a computational strategy based on molecular dynamics simulations

The human retinal pigment epithelium-specific 65-kDa protein (hRPE65) plays a crucial role within the retinoid visual cycle and several mutations affecting either its expression level or its enzymatic function are associated with inherited retinal diseases such as Retinitis Pigmentosa. The gene therapy product voretigene neparvovec (Luxturna) has been recently approved for treating hereditary retinal dystrophies; however, the treatment is currently accessible only to patients presenting confirmed biallelic mutations that severely impair hRPE65 function, and many reported hRPE65 missense mutations lack sufficient evidences for proving their pathogenicity. In this context, we developed a computational approach aimed at evaluating the potential pathogenic effect of hRPE65 missense variants located on the dimerisation domain of the protein. The protocol evaluates how mutations may affect folding and conformation stability of this protein region, potentially helping clinicians to evaluate the eligibility for gene therapy of patients diagnosed with this type of hRPE65 variant of uncertain significance.     

Amplified fragment length polymorphism for genetic diversity assessment in globe artichoke

Globe artichoke (Cynara cardunculus L. var. scolymus L.) is a diploid (2n=2x=34), predominantly cross-pollinated plant native to the Mediterranean basin, and Italy contains the richest primary cultivated gene pool. Commercial production is mainly based on perennial cultivation of vegetatively propagated clones that are highly heterozygous and segregate widely when progeny-tested. Analysis of the artichoke genome by means of molecular markers has been limited to a few studies; here we report on the genetic relatedness among 118 artichoke accessions, including clones belonging to the same varietal type, two accessions of cultivated cardoon (C. cardunculus L. var. altilis DC.) and four accessions of wild cardoon [C. cardunculus L. var. sylvestris (Lamk) Fiori] as measured by amplified fragment length polymorphism (AFLP). Eight primer combinations yielded a total of 667 bands, of which 519 were polymorphic. Genetic similarities among accessions were calculated according to Jaccards Similarity Index and used to construct a dendrogram based on the unweighted pair group method using arithmetic averages. Our results demonstrate that AFLP markers can be useful in evaluating Cynara cardunculus genetic diversity and in classifying accessions to phylogenetic groups based on their genetic similarity values. Genetic variation among artichoke clones belonging to the same varietal type was in some cases higher than that found among accessions differently named and coming from different areas. The lowest Jaccards Similarity Index found within a varietal type can be considered as a threshold for the identification of accessions which share an analogous genetic background. This will enable the selection of representatives in order to develop and manage a germplasm core collection as well as the identification of suitable material for future artichoke breeding efforts.Communicated by J.S. Heslop-Harrison     

Malondialdehyde production from spermine by homogenates of normal and transformed cells

The oxidation of spermine in vitro by a mixture of polyamine oxidase and diamine oxidase from pig kidney gives rise to malondialdehyde via 3-aminopropanol as the intermediate. Conversely, with spermidine, under similar experimental conditions, no evidence could be obtained for malondialdehyde formation within the limits of sensitivity of the assay (2.0 nmol). The activities of both these enzymes show about a 2-fold increase in normal rat kidney cells (LA31 NRK) transformed by the temperature sensitive mutant of Rous sarcoma virus (LA31) and incubated at the non permissive temperature (39 degrees C) compared to the activities in LA31 NRK at the permissive temperature (33 degrees C). These same enzymatic activities show no temperature dependent changes in normal rat kidney cells (NRK) or in these same cells infected by the wild type virus (NRK B77). In extracts derived from Friend erythroleukemic cells induced to differentiate by dimethyl sulfoxide or hexamethylene bis acetamide, spermine oxidation takes place more efficiently than in non induced cells. A rise in diamine oxidase activity is seen in LA31 NRK (39 degrees C) 12 h after the temperature shift, whereas morphological manifestations of normalcy are seen only at 48 h. The Km of diamine oxidase is 10(-6) M for putrescine and 10(-3) M for 3-aminopropanol. A possible mechanism involving the well documented acetylation of putrescine [23,26] is proposed for diverting intracellular putrescine away from cytosolic diamine oxidase and towards intramitochondrial monoamine oxidase.     

Prefrontal deep projection neurons enable cognitive flexibility via persistent feedback monitoring

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