T cell maturation is significantly affected by SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) is a respiratory tract infection caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). An adequate T cell response is essential not only for fighting disease but also for the creation of immune memory. Thus, the present study aims to evaluate the T cells of patients with moderate, severe and critical COVID-19 not only at the time of illness but also 2 months after diagnosis to observe whether changes in this compartment persist. In this study, 166 COVID-19 patients were stratified into moderate/severe and critical disease categories. The maturation and activation of T cells were evaluated through flow cytometry. In addition, Treg cells were analysed. Until 15 days after diagnosis, patients presented a reduction in absolute and relative T lymphocyte counts. After 2 months, in moderate/severe patients, the counts returned to a similar level as that of the control group. In convalescent patients who had a critical illness, absolute T lymphocyte values increased considerably. Patients with active disease did not show differentiation of T cells. Nonetheless, after 2 months, patients with critical COVID-19 showed a significant increase in CD4+ EMRA (CD45RA+ effector memory) T lymphocytes. Furthermore, COVID-19 patients showed delayed T cell activation and reduced CD8+ suppressor T cells even 2 months after diagnosis. A reduction in CD4+ Treg cells was also observed, and their numbers returned to a similar level as that of healthy controls in convalescent patients. The results demonstrate that COVID-19 patients have a delayed activation and differentiation of T cells. In addition, these patients have a great reduction of T cells with a suppressor phenotype.

The relationship between peripheral immune response and disease severity in SARS-CoV-2-infected subjects: A cross-sectional study.

Coronavirus disease 2019 (COVID-19) is a respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and marked by an intense inflammatory response and immune dysregulation in the most severe cases. In order to better clarify the relationship between peripheral immune system changes and the severity of COVID-19, this study aimed to evaluate the frequencies and absolute numbers of peripheral subsets of neutrophils, monocytes, and dendritic cells (DCs), in addition to quantifying the levels of inflammatory mediators. One hundred fifty-seven COVID-19 patients were stratified into mild, moderate, severe, and critical disease categories. The cellular components and circulating cytokines were assessed by flow cytometry. Nitric oxide (NOx) and myeloperoxidase (MPO) levels were measured by colourimetric tests. COVID-19 patients presented neutrophilia, with signs of emergency myelopoiesis. Alterations in the monocytic component were observed in patients with moderate to critical illness, with an increase in classical monocytes and a reduction in nonclassical monocytes, in addition to a reduction in the expression of HLA-DR in all subtypes of monocytes, indicating immunosuppression. DCs, especially plasmacytoid DCs, also showed a large reduction in moderate to critical patients. COVID-19 patients showed an increase in MPO, interleukin (IL)-12, IL-6, IL-10, and IL-8, accompanied by a reduction in IL-17A and NOx. IL-10 levels ≥14 pg/ml were strongly related to the worst outcome, with a sensitivity of 78·3% and a specificity of 79·1%. The results of this study indicate the presence of systemic effects induced by COVID-19, which appear to be related to the pathophysiology of the disease, highlighting the potential of IL-10 as a possible prognostic biomarker for COVID-19.

Perinatal exposure to a glyphosate pesticide formulation induces offspring liver damage.

The present study investigated the effects of perinatal exposure to glyphosate-based herbicide (GBH) in offspring's liver. Pregnant Wistar rats were exposed to GBH (70 mg glyphosate/Kg body weight/day) in drinking water from gestation day 5 to postnatal day 15. The perinatal exposure to GBH increased 45Ca2+ influx in offspring's liver. Pharmacological tools indicated a role played by oxidative stress, phospholipase C (PLC) and Akt pathways, as well as voltage-dependent Ca2+ channel modulation on GBH-induced Ca2+ influx in offspring's liver. In addition, changes in the enzymatic antioxidant defense system, decreased GSH content, lipid peroxidation and protein carbonylation suggest a connection between GBH-induced hepatotoxic mechanism and redox imbalance. The perinatal exposure to GBH also increased the enzymatic activities of transaminases and gamma-glutamyl transferase in offspring's liver and blood, suggesting a pesticide-induced liver injury. Moreover, we detected increased iron levels in liver, blood and bone marrow of GBH-exposed rats, which were accompanied by increased transferrin saturation and decreased transferrin levels in blood. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were increased in the liver of rats perinatally exposed to GBH, which were associated with. Increased phospho-p65NFκB immunocontent. Therefore, we propose that excessive amounts of iron in offspring's liver, blood and bone marrow induced by perinatal exposure to GBH may account for iron-driven hepatotoxicity, which was associated with Ca2+ influx, oxidative damage and inflammation. Further studies will clarify whether these events can ultimately impact on liver function.

Involvement of the NF-κB and PI3K/Akt/mTOR pathways in cell death triggered by stypoldione, an o-quinone isolated from the brown algae Stypopodium zonale.

Multiple myeloma (MM) is a clonal plasma cell malignancy that remains incurable to date. Thus, the aims of this study were to evaluate the involvement of the NF-κB and PI3K/Akt/mTOR pathways in the cytotoxicity of stypoldione, an o-quinone isolated from the brown algae Stypopodium zonale, in MM cells (MM1.S). The cytotoxic effect was evaluated in MM1.S cells and peripheral blood mononuclear cells (PBMCs) by MTT assay. The stypoldione reduced the cell viability of MM1.S cells in a concentration and time-dependent manner (IC50 in MM.1S from 2.55 to 5.38 µM). However, it was also cytotoxic to PBMCs, but at a lower range. Additionally, no significant hemolysis was observed even at concentration up to 10 times the IC50 . Apoptotic cell death was confirmed by cell morphology and Annexin V-FITC assay. Stypoldione induced intrinsic and extrinsic apoptosis by increasing FasR expression and reactive oxygen species (ROS) production, inverting the Bax/Bcl-2 ratio, and inducing ΔΨm loss, which resulted in AIF release and caspase-3 activation. It also increased Ki-67 and survivin expression and inhibited the NF-κB and PI3K/Akt/mTOR pathways. These results suggest that stypoldione is a good candidate for the development of new drugs for MM treatment.

Synthesis of chalcones derived from 1-naphthylacetophenone and evaluation of their cytotoxic and apoptotic effects in acute leukemia cell lines.

Chalcones and their derivatives have been described as promising compounds with antiproliferative activity against leukemic cells. This study aimed to investigate the cytotoxic effect of three synthetic chalcones derived from 1-naphthylacetophenone (F07, F09, and F10) in acute leukemia cell lines (K562 and Jurkat) and examine the mechanisms of cell death induced by these compounds. The three compounds were cytotoxic to K562 and Jurkat cells, with IC50 values ranging from 1.03 to 31.66 µM. Chalcones induced intrinsic and extrinsic apoptosis, resulting in activation of caspase-3 and DNA fragmentation. F07, F09, and F10 were not cytotoxic to human peripheral blood mononuclear cells, did not produce any significant hemolytic activity, and did not affect platelet aggregation after ADP stimulation. These results, combined with calculations of molecular properties, suggest that chalcones F07, F09, and F10 are promising molecules for the development of novel antileukemic drugs.

Cell Cycle Arrest and Apoptosis Induction by a New 2,4-Dinitrobenzenesulfonamide Derivative In Acute Leukemia Cells.

BACKGROUND: Current therapies for acute leukemias (ALs) are associated with severe adverse reactions and high relapse rates, which makes the search for new antileukemic agents a necessity. Therefore, the aim of this study was to evaluate the effects of a new sulfonamide, S1, in AL cells K562 and Jurkat. METHODS: The cytotoxic activity of S1 was assessed using MTT method. The involvement of apoptosis in the mechanism of cell death was assessed by flow cytometry and fluorescence microscopy. RESULTS: Our results demonstrated that S1 induced morphological changes suggestive of apoptosis in both K562 and Jurkat cells. Additionally, S1 was not cytotoxic to normal erythrocytes and mononuclear cells and had a highly selective cytotoxicity for AL lineages. The mechanisms of cell death induced by S1 in K562 cells involves cell cycle arrest at G2/M phase and the activation of both extrinsic and intrinsic apoptosis, with an increased FasR and AIF expression and the loss of mitochondrial potential. As for Jurkat, we observed cell cycle blockade at G0/G1 phase, phosphatidylserine exposure and the involvement of intrinsic apoptosis only, with mitochondrial potential loss and a reduced expression of Survivin.  Although sulfonamide S1 did not altered Bcl-2 and Bax expression in AL cell lines, it was able to activate caspase-3 in K562 cells. CONCLUSION: Our results suggest that sulfonamide S1 may be a promising candidate for the development of new drugs for the treatment of ALs.

Immune response of Brazilian farmers exposed to multiple pesticides.

Occupational exposure to pesticides has been identified as a factor that predisposes to disorders of the immune system. Immunosuppression, autoimmunity, cancer of various organs and other diseases in people who apply these products have been reported by the studies. This study aimed to investigate the relationship between occupational exposure to pesticides and the immunological profile in 43 farmers exposed to mixtures of pesticides for at least 15 years. A control group composed of 30 individuals without a history of occupational exposure to pesticides was also evaluated. Peripheral blood samples were processed by flow cytometry and cells were labelled with an 8-color monoclonal antibody panel. Plasma cytokines were also measured. Significant increase in classical monocytes (p < 0.001) and dendritic cells (p < 0.001) in the exposed group was observed as well in total T cells (p = 0.04), central memory CD8 T cells (p = 0.02) and effector memory CD8 T cells (p = 0.01). On the other hand, the activation markers of T cells as the expression of CD57, HLA-DR, CD25 and CD28 were evaluated and no difference was found between groups. When the B cells were analyzed, a significant decrease in total B cells (p = 0.01), regulatory B cells (p < 0.001) and plasmablasts (p < 0.001) in the exposed group, compared to healthy controls, was observed. Pro-inflammatory IL-6 was significantly elevated (p = 0.04) in the plasma of farmers compared to that of controls. The constant antigenic stimulus that occurs during exposure to pesticides can favor the recruitment of dendritic cells and macrophages (APCs) presents in the skin and respiratory tract. In the secondary lymphoid organs, the CD4 T and B cells that process such antigens are possibly undergoing proliferative exhaustion, with the consequent depletion of all mature B subpopulations. The resulting drop in humoral immunity may be offset by an increase in the number of circulating CD8 T lymphocytes due to their cytotoxic action.

MICONIDINE acetate, a new selective and cytotoxic compound with synergic potential, induces cell cycle arrest and apoptosis in leukemia cells.

Plants are important sources of biologically active compounds and they provide unlimited opportunities for the discovery and development of new drug leads, including new chemotherapeutics. Miconidin acetate (MA) is a hydroquinone derivative isolated from E. hiemalis. In this study we demonstrated that MA was cytotoxic against acute leukemia (AL), solid tumor cells and cancer stem cells, with the strongest effect exhibited against AL. Furthermore, it was non-cytotoxic against non-tumor cells and did not cause significant hemolysis. MA blocks the G2/M phase and causes cytostatic effects, acting in a similar way to dexamethasone by increasing PML expression. The compound also triggered intrinsic and extrinsic apoptosis by modulating Bax, FasR and survivin expression. This led to an extensive mitochondrial damage that resulted in AIF, cytochrome c and endonuclease G release, caspase-3 and PARP cleavage and DNA fragmentation. We have further demonstrated that MA was strongly cytotoxic against neoplastic cells collected from patients with different AL subtypes. Interestingly, MA increased the cytotoxic effect of chemotherapeutics cytarabine and vincristine. This study indicates that MA may be a new agent for AL and highlights its potential as a new source of anticancer drugs. Graphical abstract MA blocks G2/M phase with PML expression and KI67 inhibition, ROS generation and intrinsic and extrinsic apoptosis, leading to mitochondrial damage, caspase 3 and PARP cleavage and DNA fragmentation.

Synthesis of novel pyrazoline derivatives and the evaluation of death mechanisms involved in their antileukemic activity.

Malignant neoplasms are one of the leading causes of death worldwide and hematologic malignancies, including acute leukemia (AL) is one of the most relevant cancer types. Current available chemotherapeutics are associated with high morbidity and mortality rates, therefore, the search for new molecules with antitumor activity, specific and selective for neoplastic cells, became a great challenge for researchers in the oncology field. As pyrazolines stand out in the literature for their great variety of biological activities, the aim of this study was to synthesize and evaluate the antileukemic activity of five new pyrazoline derivatives. All pyrazolines showed adequate physicochemical properties for a good oral bioavailability. The two unpublished and most effective pyrazoline derivatives have been selected for further experiments. These compounds are highly selective for leukemic cells when compared to non-neoplastic cells and did not cause lysis on human red blood cells. Additionally, selected pyrazolines induced cell cycle arrest at G0/G1 phase and decreased cell proliferation marker KI67. Apoptotic cell death induced by selected pyrazolines was confirmed by morphological analysis, assessment of phosphatidylserine residue exposure and DNA fragmentation. Several factors indicate that both intrinsic and extrinsic apoptosis occurred. These were: increased FasR expression; the predominance of Bax in relation to Bcl-2; the loss of mitochondrial membrane potential; AIF release; decreased expression of survivin (an antiapoptotic protein); and the activation of caspase-3. The selected pyrazolines were also found to be cytotoxic against neoplastic cells collected from the peripheral blood and bone marrow of patients with different subtypes of acute leukemia.

Effects of 1,3,5-triphenyl-4,5-dihydro-1H-pyrazole derivatives on cell-cycle and apoptosis in human acute leukemia cell lines.

Pyrazoline is an important 5-membered nitrogen heterocycle that has been extensively researched. Ten derivatives were synthesized and tested for antileukemic effects on 2 human acute leukemia cell lines, K562 and Jurkat. The most cytotoxic of these derivatives, compound 21, was chosen for investigation of cytotoxicity mechanisms. The results obtained with selectivity calculations revealed that compound 21 is more selective for acute leukemia (K562 and Jurkat cell lines) than for other tumor cell lines. Moreover, compound 21 was not cytotoxic to normal cell lines, indicating a potential use in clinical tests. Compound 21 caused a significant cell cycle arrest in the S-phase in Jurkat cells and increased the proportion of cells in the sub G0/G1 phase in both cell lines. Cells treated with compound 21 demonstrated morphological changes characteristic of apoptosis in the EB/AO assay, confirmed by externalization of phosphatidylserine by the annexin V - fluorescein isothiocyanate method and by DNA fragmentation. An investigation of cytotoxicity mechanisms suggests the involvement of an intrinsic apoptosis pathway due to mitochondrial damage and an increase in the ratio of mitochondrial Bax/Bcl2. Pyrazoline 21 obeyed Lipinski's "rule of five" for drug-likeness. Based on these preliminary results, the antileukemic activity of compound 21 makes it a potential anticancer agent.

Oral Delivery of a High Quercetin Payload Nanosized Emulsion: In Vitro and In Vivo Activity Against B16-F10 Melanoma.

Quercetin is a natural compound that has several biological activities including anticancer activity. However, the use of this drug has been limited mostly because of its poor water solubility and low bioavailability. Therefore, the development of quercetin-loaded nanocarrier systems may be considered a promising advance to exploit its therapeutic properties in clinical setting including cancer treatment. This study evaluates the effect of orally administered nanosized emulsion containing quercetin (QU-NE) on the cytotoxicity activity against B16-F10 cells in vitro, and on subcutaneous melanoma in mice inoculated with B16-F1O cells. In vivo experiments, also evaluate the co-administration of quercetin with cisplatin in order to predict synergic effects and the renal and hepatic toxicity. The nanocarriers were prepared through the hot solvent diffusion associated with the phase inversion temperature methods. In vitro study showed reduction of cell viability in a concentration-depend manner for free quercetin and QU-NE. In vivo study, quercetin either as a free drug or colloidal dispersion was administrated at a dose of 5 mg kg(-1) twice a week for 17 days via oral route. Cisplatin was administrated at dose of 1 mg kg(-1) once a week intraperitoneally. Free quercetin and QU-NE reduced tumor growth, however, the reduction observed for QU-NE (P < 0.001 vs. control) was significantly higher than free quercetin (P < 0.05 vs. control). The association of both drugs did not show synergic effect. Besides, no renal or hepatic toxicities were observed after administration of free quercetin and QU-NE. These results suggest that an improvement in the oral bioavailability of quercetin occurred when this compound was dissolved in the oily phase of a nanosized emulsion, indicating that it might have a potential application in the treatment of melanoma.

Increased cellular uptake of lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles due to surface modification with folic acid.

Lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles surface modified with folic acid were synthesized by miniemulsion polymerization in just one step. In vitro biocompatibility and cytotoxicity assays on L929 (murine fibroblast), human red blood, and HeLa (uterine colon cancer) cells were performed. The effect of folic acid at the nanoparticles surface was evaluated through cellular uptake assays in HeLa cells. Results showed that the presence of folic acid did not affect substantially the polymer particle size (~120 nm), the superparamagnetic behavior, the encapsulation efficiency of lauryl gallate (~87 %), the Zeta potential (~38 mV) of the polymeric nanoparticles or the release profile of lauryl gallate. The release profile of lauryl gallate from superparamagnetic poly(methyl methacrylate) nanoparticles presented an initial burst effect (0-1 h) followed by a slow and sustained release, indicating a biphasic release system. Lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles with folic acid did not present cytotoxicity effects on L929 and human red blood cells. However, free lauryl gallate presented significant cytotoxic effects on L929 and human red blood cells at all tested concentrations. The presence of folic acid increased the cytotoxicity of lauryl gallate loaded in nanoparticles on HeLa cells due to a higher cellular uptake when HeLa cells were incubated at 37 °C. On the other hand, when the nanoparticles were incubated at low temperature (4 °C) cellular uptake was not observed, suggesting that the uptake occurred by folate receptor mediated energy-dependent endocytosis. Based on presented results our work suggests that this carrier system can be an excellent alternative in targeted drug delivery by folate receptor.

Curcumin-Loaded Chitosan-Coated Nanoparticles as a New Approach for the Local Treatment of Oral Cavity Cancer.

Mucoadhesive nanoparticles loaded with curcumin were developed as a new approach to deliver curcumin for the local treatment of oral cancer. PCL nanoparticles coated with chitosan displaying different molar masses were prepared by using the nanoprecipitation technique. The mucoadhesive properties of nanoparticle suspensions were demonstrated by their strong ability to interact with the glycoprotein mucin through electrostatic interactions. Similar permeation profiles of curcumin loaded in uncoated and chitosan-coated nanoparticles across porcine esophageal mucosa were verified. Curcumin concentrations retained in the mucosa suggest the possibility of a local effect of the drug. In vitro studies demonstrated that free curcumin.and curcumin loaded into nanoparticles coated with chitosan caused significant reduction of SCC-9 human oral cancer cell viability in a concentration and time-dependent manner. However, no significant cell death was observed after 24 h of treatment with unloaded nanoparticles coated with chitosan. In addition, curcumin-loaded nanoparticles showed reduced cytotoxicity, when compared with the free drug. Therefore, chitosan-coated PCL nanoparticles may be considered a promising strategy to deliver curcumin directly into the oral cavity for the treatment of oral cancer.

Sodium diethyldithiocarbamate trihydrate: an effective and selective compound for hematological malignancies.

Myeloid leukemias and lymphomas are among the most common and well-studied hematological malignancies. However, due to the aggressiveness and rapid progression of certain subtypes, treating these diseases remains a challenge. Considering the promising results of diethyldithiocarbamates in preclinical and clinical oncology trials, this study aimed to investigate the potential of sodium diethyldithiocarbamate trihydrate (DETC) as a prototype for developing new drugs to treat hematological malignancies. In silico analysis using SwissADME was conducted to evaluate the physicochemical characteristics and pharmacokinetic properties of DETC. An in vitro investigation utilizing the MTT assay assessed the cytotoxic effects of DETC on neoplastic and non-neoplastic cell lines. Selectivity was determined using a selectivity index and a hemolysis assay, while the mechanism of cell death in neoplastic cell lines was examined through flow cytometry analysis of pro-apoptotic and anti-apoptotic protein levels. The results demonstrated that the physicochemical characteristics of DETC are suitable for oral administration. Furthermore, the compound showed promising cytotoxic activity against human myeloid leukemia (K562) and Burkitt's lymphoma (Daudi) cell lines, with high selectivity for neoplastic cells over non-neoplastic cells of the bone marrow microenvironment (HS-5 cell line). Moreover, hemolysis was observed only at very high concentrations. The cytotoxicity mechanism of DETC against both neoplastic cell lines involved cell cycle arrest and the production of reactive oxygen species. In K562 cells, cell death was induced via apoptosis. Additional experiments are needed to confirm the exact mechanism of cell death in Daudi Burkitt's lymphoma cells.

Lymphocyte B Subtypes in Peripheral Blood: A Prognostic Biomarker for COVID-19 Patients.

BACKGROUND: In view of the scientific gap in knowledge of the involvement of the B-cell compartment and clinical prognostic in SARS-CoV-2 infection, this work aims to evaluate the B-cell subsets and the presence of specific IgM and IgG, as well as neutralizing antibodies against SARS-CoV-2, in unvaccinated patients diagnosed with COVID-19. METHODS: This study included 133 patients with COVID-19. Cellular components were assessed by flow cytometry, and immunoglobulin levels and reactivity were measured by indirect enzyme-linked immunosorbent assay. RESULTS: Our results showed no changes in less differentiated B cells. However, non-switched memory B cells (NS-MBCs) and class-switched memory B cells (CS-MBCs) were reduced in the patients with moderate disease. Also, plasmablasts and double-negative (DN) or "atypical" memory B cells were increased in groups of patients with moderate to critical conditions. In addition, the production of IgM, IgG, and neutralizing antibodies against SARS-CoV-2 demonstrated a positive correlation between the positivity of antibodies against SARS-CoV-2 and disease severity. Besides being related to the development of a more severe course of the disease, the increase in DN B-cell count also contributed to a poorer disease outcome in patients with a higher percentage of these cells. On the other hand, we observed an increase in the absolute number of CS-MBCs in patients with greater chances of survival. CONCLUSIONS: This study demonstrates that the B-cell compartment may contribute to the development of clinical symptoms of COVID-19, with changes in B-cell subset counts linked to disease course and patient prognosis.

Apoptotic events induced by maleimides on human acute leukemia cell lines.

Cyclic imides are known for their antitumor activity, especially the naphthalimide derivatives, such as Mitonafide and Amonafide. Recently, we have demonstrated the cytotoxic effect of a series of naphthalimide derivatives against B16F10 melanoma cells. On the basis of this fact, we have developed a study starting from the synthesis of different cyclic imides and the evaluation of their cytotoxic properties on human acute leukemia cells (K562 and Jurkat). Initially, a screening test was conducted to select the compound with the best cytotoxic effect, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. After this selection, structural modifications were performed in the most active compound to obtain five more derivatives. All compounds presented a good cytotoxic effect. The results of cell cycle analysis, fluorescence microscopy, and Annexin V-FITC assay confirmed that the cells observed in the sub-G0/G1 phase were undergoing apoptosis. From this set of results, cyclic imides 8, 10, and 12 were selected for the evaluation of the mechanisms involved in the apoptotic process. The results demonstrate the involvement of the intrinsic pathway of apoptosis, evidenced by the reduction in mitochondrial potential, an increase in the level of AIF protein expression, a decreased level of expression of anti-apoptotic Bcl-2 protein, and an increased level of expression of pro-apoptotic protein Bax in both K562 and Jurkat cells treated with cyclic imides (8, 10, and 12). Furthermore, cyclic imides 8 and 10 caused an increase in the level of Fas expression in Jurkat cells, indicating the additional involvement of the extrinsic apoptosis pathway. The compounds (8, 10, and 12) also caused a decreased level of expression of anti-apoptotic protein survivin. The biological effects observed with these cyclic imide derivatives in this study suggest promising applications against acute leukemia.

Comparison between two portable hemoglobinometers and a reference method to verify the reliability of screening in blood donors.

Portable hemoglobinometers are used to determine hemoglobin level, but there are conflicting reports regarding their accuracy. The aim of this study was to compare results from two portable hemoglobinometers (HemoCue® and Hemo-Control) with an automated hematology analyzer (Sysmex XE-2100D) to determine if the screening of blood donors is reliable. A total of 426 blood donors' samples were studied and on average the Hb content measured in capillary blood samples was higher than that found in venous blood samples. Hemoglobinometers can be employed as a method to screen blood donors, but critical values should be confirmed in an automated hematology analyzer.

Importance of detecting multidrug resistance proteins in acute leukemia prognosis and therapy.

Multidrug resistance (MDR) is a multifactorial phenomenon and the role of these proteins in generating the MDR phenotype is controversial. With this in mind, this review compiled the current data on the role of ABCB1, ABCC1, and LRP proteins in the prognosis of hematologic neoplasms and their influence on the choice of therapy. Literature showed that the detection of these proteins, mainly ABCB1, is important in the AL prognosis. However, there is controversy regarding the methodology used for their detection. In summary, the expression and activity profiles of ABCB1, ABCC1, and LRP, proteins capable of promoting the efflux of a variety of chemotherapeutic agents from the cell cytoplasm represent one of the greatest causes of failure in AL treatment.

Omics-based identification of an NRF2-related auranofin resistance signature in cancer: Insights into drug repurposing.

Auranofin is a thioredoxin reductase-1 inhibitor originally approved for the treatment of rheumatoid arthritis. Recently, auranofin has been repurposed as an anticancer drug, with pharmacological activity reported in multiple cancer types. In this study, we characterized transcriptional and genetic alterations associated with auranofin response in cancer. By integrating data from an auranofin cytotoxicity screen with transcriptome profiling of lung cancer cell lines, we identified an auranofin resistance signature comprising 29 genes, most of which are classical targets of the transcription factor NRF2, such as genes involved in glutathione metabolism (GCLC, GSR, SLC7A11) and thioredoxin system (TXN, TXNRD1). Pan-cancer analysis revealed that mutations in NRF2 pathway genes, namely KEAP1 and NFE2L2, are strongly associated with overexpression of the auranofin resistance gene set. By clustering cancer types based on auranofin resistance signature expression, hepatocellular carcinoma, and a subset of non-small cell lung cancer, head-neck squamous cell carcinoma, and esophageal cancer carrying NFE2L2/KEAP1 mutations were predicted resistant, whereas leukemia, lymphoma, and multiple myeloma were predicted sensitive to auranofin. Cell viability assays in a panel of 20 cancer cell lines confirmed the augmented sensitivity of hematological cancers to auranofin; an effect associated with dependence upon glutathione and decreased expression of NRF2 target genes involved in GSH synthesis and recycling (GCLC, GCLM and GSR) in these cancer types. In summary, the omics-based identification of sensitive/resistant cancers and genetic alterations associated with these phenotypes may guide an appropriate repurposing of auranofin in cancer therapy.

Effect of nitric oxide on the daunorubicin efflux mechanism in K562 cells.

NO (nitric oxide) donating drugs have been investigated for their important role in the sensitization of neoplastic cells to chemotherapy drugs. The goal of this work was to investigate the involvement of NO in the resistance of K562 cells to DNR (daunorubicin). Only simultaneous addition of DNR and SNAP (S-nitroso-N-acetyl-dl-penicillamine) caused significant cell death by apoptosis. Combination of the compounds decreased Bcl-2 and survivin, and increased Bax and active-caspase 3 expression. Fluorescence microscope and cytometric analysis showed that DNR and SNAP together caused DNR intracellular accumulation in K562 cells. RT-PCR (reverse transcription-PCR) analysis showed that DNR and SNAP, alone or in association, produced significant decreases in lrp expression. abcc1 gene expression was unaffected by the presence of SNAP, but when treated with DNR there was a small reduction that was intensified by DNR and SNAP in combination. The transport mechanism involved in the resistance to DNR in K562 cells involves ABCC1 and LRP (lung resistance protein) resistance proteins. DNR and SNAP inhibition of the expression of these proteins occurs by distinct mechanisms, and this disrupts the K562 resistance to DNR.