Fusion of Tumor-Derived Exosomes with Long-Circulating and pH-Sensitive Liposomes Loaded with Doxorubicin for the Treatment of Breast Cancer.

Doxorubicin (DOX) is a chemotherapeutic agent that has been used in the treatment of breast cancer. However, serious toxic effects have limited its use, mainly cardiotoxicity. To minimize the adverse effects, liposomal preparations containing DOX have been developed. These preparations can reach the target in the tumor region as well as bypass the resistance-related problems. An alternative to increased therapeutic efficacy may be the fusion of liposomes with exosomes released from tumor cells to facilitate membrane and fusion interactions, achieving greater cell uptake. Thus, the purpose of this study was the fusion of exosomes derived from breast tumor cells with long-circulating and pH-sensitive liposomes loading DOX (ExoSpHL-DOX) for the treatment of breast cancer. The mean diameter of ExoSpHL-DOX was 100.8 ± 7.8 nm, the polydispersity index was 0.122 ± 0.004, and the encapsulated DOX content was equal to 83.5 ± 2.5%. The fusion of exosomes with long-circulating and pH-sensitive liposomes was confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy, and nano-flow cytometry. The physicochemical characteristics of ExoSpHL-DOX were maintained for 60 days, at 4 °C. The study of the release of DOX from ExoSpHL-DOX in dilution media with different pH values showed the pH sensitivity characteristic of the nanosystem, since 96.6 ± 0.2% of DOX was released from ExoSpHL-DOX at pH 5.0, while at pH 7.4, the release was 70.1 ± 1.7% in the medium. The cytotoxic study against the breast cancer cell line demonstrated that ExoSpHL-DOX treatment significantly reduced the cancer cell viability.

Lack of association between potential prothrombotic genetic risk factors and arterial and venous thrombosis.

Recent studies have shown an association between thrombosis and factor VII (FVII), tissue factor (TF), and angiotensin-converting enzyme (ACE). This suggests that individuals with FVII-402 G/A, FVII-401 G/T, TF+5466 A/G, and ACE-287 insertion/deletion (I/D) polymorphisms present an increased risk of venous thrombosis, heart disease, and ischemic stroke compared with controls. In this study, we investigated the frequencies of these polymorphisms and their association with arterial and venous thrombosis. For the FVII-402 G/A polymorphism, there were 57.3% heterozygote (HT) genotypes and 8.3% homozygote (HM) genotypes in the patients, and 45.2% HT genotypes and 15.4% HM genotypes in the controls. For the FVII-401 G/T polymorphism, there were 37.5% HT genotypes and 3.1% HM genotypes in the patients, and 32.7% HT genotypes and 4.8% HM genotypes in the controls. The polymorphism TF+5466 A/G was not found in any of the samples analyzed. For the ACE-287 I/D polymorphism, there were 43 (40.6%) HT genotypes and 63 (59.4%) HM genotypes in the controls and 28 (45.2%) HT genotypes and 34 (54.8%) HM genotypes in the patients. No significant difference was observed by comparing patients and controls. In this study, no association was found between the presence of the evaluated polymorphisms and the occurrence of thrombotic events.

Apolipoprotein A5-1131T>C polymorphism, but not APOE genotypes, increases susceptibility for dyslipidemia in children and adolescents.

Apolipoprotein A5 (APOA5) and apolipoprotein E (APOE) play important roles in the metabolism of cholesterol and triglycerides. The aim of this study was to determine the allelic and genotypic distributions of the APOA5-1131T>C (rs 662799) and the APOE HhaI polymorphisms and to identify the association of both individual and combined APOA5-APOE genetic variants and the risk for dyslipidemia in children and adolescents. We genotyped 53 dyslipidemic and 77 normolipidemic individuals. The total cholesterol, triglycerides and HDL cholesterol were determined enzymatically. For APOA5 polymorphism, the presence of the allele C confers an individual risk for dyslipidemia (OR = 2.38, 95% CI = 1.15-4.89; P = 0.018). No significant differences were observed for lipid parameters among the APOA5 groups, except for a higher value of HDLc (P = 0.024) in C-carriers. The allelic and genotypic frequencies of APOE polymorphism were similar between groups and did not increase the susceptibility for dyslipidemia. None of the combined APOA5-APOE polymorphisms increased risk for dyslipidemia. We demonstrated an association between APOA5-1131T>C polymorphism and dyslipidemia in children and adolescents. This finding may be useful to guide new studies with genetic markers down a path toward a better characterization of the genetic risk factors for dyslipidemia and atherosclerotic diseases.

Stryphnodendron adstringens ("Barbatimão") Leaf Fraction: Chemical Characterization, Antioxidant Activity, and Cytotoxicity Towards Human Breast Cancer Cell Lines.

We evaluated the chemical composition, antioxidant activity, and antitumor potential of a fraction that was isolated from Stryphnodendron adstringens (barbatimão) leaf aqueous extract. Fraction is composed by gallic acid, procyanidin dimer B1, and (-)-epicatechin-3-O-gallate and it exhibits antioxidant and cytotoxic activities. Fraction was cytotoxic against two human breast cancer cell lines, ER (+) and MCF-7 and the triple-negative, MDA-MB-435. The sulforhodamine B assay showed that, as compared to normal control cells, the fraction significantly (P < 0.05) decreased cancer cell viability. The morphological alterations noted in the treated cancer cells were cell rounding-up, shrinkage, and nuclear condensation reduction of cell diameter and length. Treatment with fraction increased cancer cell expression of Bax, caspase-9, active caspase-3, caspase-8, LC-3, and beclin-1 and decreased Bcl-2, caspase-3, and pro-caspase-8 expression. Altogether, fraction is cytotoxic to both breast cancer cell lines, induces cell death, and its mechanism of action seems to include the induction of apoptosis. Our data support a positive role of the fraction as a chemopreventive agent for antineoplastic drug development.