Breast cancer is the main cause of mortality among women. The disease presents high recurrence mainly due to incomplete efficacy of primary treatment in killing all cancer cells. Photodynamic therapy (PDT), an approach that causes tissue destruction by visible light in the presence of a photosensitizer (Ps) and oxygen, appears as a promising alternative therapy that could be used adjunct to chemotherapy and surgery for curing cancer. However, the efficacy of PDT to treat breast tumours as well as the molecular mechanisms that lead to cell death remain unclear. In this study, we assessed the cell-killing potential of PDT using methylene blue (MB-PDT) in three breast epithelial cell lines that represent non-malignant conditions and different molecular subtypes of breast tumours. Cells were incubated in the absence or presence of MB and irradiated or not at 640 nm with 4.5 J/cm2. We used a combination of imaging and biochemistry approaches to assess the involvement of classical autophagic and apoptotic pathways in mediating the cell-deletion induced by MB-PDT. The role of these pathways was investigated using specific inhibitors, activators and gene silencing. We observed that MB-PDT differentially induces massive cell death of tumour cells. Non-malignant cells were significantly more resistant to the therapy compared to malignant cells. Morphological and biochemical analysis of dying cells pointed to alternative mechanisms rather than classical apoptosis. MB-PDT-induced autophagy modulated cell viability depending on the cell model used. However, impairment of one of these pathways did not prevent the fatal destination of MB-PDT treated cells. Additionally, when using a physiological 3D culture model that recapitulates relevant features of normal and tumorous breast tissue morphology, we found that MB-PDT differential action in killing tumour cells was even higher than what was detected in 2D cultures. Finally, our observations underscore the potential of MB-PDT as a highly efficient strategy which could use as a powerful adjunct therapy to surgery of breast tumours, and possibly other types of tumours, to safely increase the eradication rate of microscopic residual disease and thus minimizing the chance of both local and metastatic recurrence.

IL-1 axis activation during placental malaria induces poor pregnancy outcomes that are obliterated after treatment with Anakinra.

Lectins are proteins that have the ability to bind specifically and reversibly to carbohydrates and glycoconjugates, without altering the structure of the glycosyl ligand. They are found in organisms such as viruses, plants and humans, and they have been shown to possess important biological activities. The objective of this study was to purify and characterize lectins in the seeds of Clitoria fairchildiana, as well as to verify their biological activities. The results indicated the presence of a lectin (CFAL) in the glutelin acid protein fraction, which agglutinated native rabbit erythrocytes. CFAL was purified by column chromatography ion-exchange, DEAE-Sephacel, which was obtained from a peak of protein retained in the matrix by applying 0.5 M NaCl using the step-wise method. Electrophoretic analysis of this lectin in SDS-PAGE indicated a two band pattern protein molecular mass of approximately 100 and 116 kDa. CFAL proved to be unspecific to all carbohydrates/glycoconjugates in common use for the sugar inhibition test. This lectin showed no significant cytotoxicity to human red blood cells. It was observed that CFAL has anti-inflammatory activity in the paw edema induced by carrageenan model, in which a 64% diminution in edema was observed. Antinociceptive effects were observed for CFAL in the abdominal writhing test (induced by acetic acid), in which increasing doses of the lectin caused reduction in the number of contortions by up to 72%. It was concluded that the purified and characterized lectin from the seeds of Clitoria fairchildiana has anti-inflammatory and antinociceptive activity, and is not cytotoxic to human erythrocytes.

During type 1 diabetes mellitus (T1DM) development, beta-cells undergo intense endoplasmic reticulum (ER) stress that could result in apoptosis through the failure of adaptation to the unfolded protein response (UPR). Islet transplantation is considered an attractive alternative among beta-cell replacement therapies for T1DM. To avoid the loss of beta-cells that will jeopardize the transplant’s outcome, several strategies are being studied. We have previously shown that prolactin induces protection against proinflammatory cytokines and redox imbalance-induced beta-cell death by increasing heat-shock protein B1 (HSPB1) levels. Since the role of HSPB1 in beta cells has not been deeply studied, we investigated the mechanisms involved in unbalanced protein homeostasis caused by intense ER stress and overload of the proteasomal protein degradation pathway. We tested whether HSPB1-mediated cytoprotective effects involved UPR modulation and improvement of protein degradation via the ubiquitin-proteasome system. We demonstrated that increased levels of HSPB1 attenuated levels of pro-apoptotic proteins such as CHOP and BIM, as well as increased protein ubiquitination and the speed of proteasomal protein degradation. Our data showed that HSPB1 induced resistance to proteotoxic stress and, thus, enhanced cell survival via an increase in beta-cell proteolytic capacity. These results could contribute to generate strategies aimed at the optimization of beta-cell replacement therapies.

We report a series of 1,3-diphenylureido hydroxamate HDAC inhibitors evaluated against sensitive and drug-resistant P. falciparum strains. Compounds 8a–d show potent antiplasmodial activity, indicating that a phenyl spacer allows improved potency relative to cinnamyl and di-hydrocinnamyl linkers. In vitro, mechanistic studies demonstrated target activity for PfHDAC1 on a recombinant level, which agreed with cell quantification of the acetylated histone levels. Compounds 6c, 7c, and 8c, identified as the most active in phenotypic assays and PfHDAC1 enzymatic inhibition. Compound 8c stands out as a remarkable inhibitor, displaying an impressive 85% inhibition of PfHDAC1, with an IC₅₀ value of 0.74 µM in the phenotypic screening on Pf3D7 and 0.8 µM against multidrug-resistant PfDd2 parasites. Despite its potent inhibition of PfHDAC1, 8c remains the least active on human HDAC1, displaying remarkable selectivity. In silico studies suggest that the phenyl linker has an ideal length in the series for permitting effective interactions of the hydroxamate with PfHDAC1 and that this compound series could bind as well as in HsHDAC1. Taken together, these results highlight the potential of diphenylurea hydroxamates as a privileged scaffold for the generation of potent antimalarial HDAC inhibitors with improved selectivity over human HDACs.