The aim of this study was to investigate whether (−)-epicatechin (EC) can induce DNA damage and apoptosis of cancer cells in the spleen of rat with acute myeloid leukemia. Healthy and leukemic rats ...were given EC by gavage at a dose of 40
mg/kg
b.w. for 22 consecutive days. Spleen cells were subjected for analysis of DNA damage and apoptosis. The amount of DNA damage was estimated by the comet assay, while apoptosis was examined by flow cytometry using Annexin V staining. Leukemic cells were identified in the spleen cells by indirect immunofluorescence using RM-124 antibody followed by flow cytometry analysis. The results show that EC did not affect DNA damage in the splenocytes of healthy rats, but significantly increased the extent of DNA strand breaks in the spleen cells of leukemic animals. EC administration to leukemic rats induced a significant increase in the level of Annexin V-positive leukemic cells, but the level of non-leukemic Annexin V-positive cells remained unchanged in comparison to control. The percentage of leukemic cells decreased significantly under EC influence comparing to the untreated group. The results of the study reveal that EC could be used as an effective supplement of standard therapy against acute myeloid leukemia.
Exercise training remains a therapy of choice in intermittent claudication (IC). However, too exhaustive exercise may cause ischaemic injury and inflammatory response. We tested the impact of ...three-month treadmill training and single treadmill exercise on antioxidant gene expressions, cytokine concentrations and number of marrow-derived proangiogenic progenitor cells (PPC) in the blood of IC patients. Blood samples of 12 patients were collected before and after training, before and 1, 3 and 6 hours after the single exercise. PPCs were analysed with flow cytometry, cytokine concentrations were checked with Milliplex MAP, while expression of mRNAs and miRNAs was evaluated with qRT-PCR. Treadmill training improved pain-free walking time (from 144 ± 44 seconds s to 311 ± 134 s, p=0.02) and maximum walking time (from 578 ± 293 s to 859 ± 423 s, p=0.01) in IC patients. Before, but not after training, the single treadmill exercise increased the number of circulating CD45dimCD34+CD133-KDR+ PPCs (p=0.048), decreased expression of HMOX1 (p=0.04) in circulating leukocytes, reduced tumour necrosis factor-α (p=0.03) and tended to elevate myeloperoxidase (p=0.06) concentrations in plasma. In contrast, total plasminogen activator inhibitor-1 was decreased by single exercise only after, but not before training (p=0.02). Both before and after training the single exercise decreased monocyte chemoattractant protein (MCP)-1 (p=0.006 and p=0.03) concentration and increased SOD1 (p=0.001 and p=0.01) expression. Patients after training had also less interleukin-6 (p=0.03), but more MCP-1 (p=0.04) in the blood. In conclusion, treadmill training improves walking performance of IC patients, attenuates the single exercise-induced changes in gene expressions or PPC mobilisation, but may also lead to higher production of some proinflammatory cytokines.
(-)-Epicatechin (EC) is a naturally occurring compound which induces oxidative DNA damage in human acute myeloid leukaemia (AML) cells.
The aim of the study was to examine the influence of EC on the ...antileukaemic effect of etoposide in rats with AML.
Brown Norway rats with AML were treated with EC for 23 days and etoposide was administered for the last three days of the experiment. Bone marrow and splenic cell apoptosis was investigated by flow cytometry using annexin V-allophycocyanin staining. The oxidative status was investigated in homogenates of the liver.
EC was found to increase the in vivo apoptotic effect of etoposide resulting in the decrease of the percentage of leukaemia cells in EC-treated rats in comparison to those treated with etoposide only. Investigation of malondialdehyde and ferric ion-reducing ability of plasma levels indicated that EC increases the oxidative stress induced by etoposide in leukaemic rats.
EC can enhance the antileukaemia properties of etoposide in vivo through augmentation of oxidative stress.
Curcumin may exert a more selective cytotoxic effect in tumor cells with elevated levels of free radicals. Here, we investigated whether curcumin can modulate etoposide action in myeloid leukemia ...cells and in normal cells of hematopoietic origin. HL-60 cell line, normal myeloid progenitor cluster of differentiation (CD)-34(+) cells, and granulocytes were incubated for 4 or 24 hours at different concentrations of curcumin and/or etoposide. Brown Norway rats with acute myeloid leukemia (BNML) were used to prove the influence of curcumin on etoposide action in vivo. Rats were treated with curcumin for 23 days and etoposide was administered for the final 3 days of the experiment. Curcumin synergistically potentiated the cytotoxic effect of etoposide, and it intensified apoptosis and phosphorylation of the histone H2AX induced by this cytostatic drug in leukemic HL-60 cells. In contrast, curcumin did not significantly modify etoposide-induced cytotoxicity and H2AX phosphorylation in normal CD34(+) cells and granulocytes. Curcumin modified the cytotoxic action of etoposide in HL-60 cells through intensification of free radical production because preincubation with N-acetyl-l-cysteine (NAC) significantly reduced the cytotoxic effect of curcumin itself and a combination of two compounds. In contrast, NAC did not decrease the cytotoxic effect of etoposide. Thus, oxidative stress plays a greater role in the cytotoxic effect of curcumin than that of etoposide in HL-60 cells. In vitro results were confirmed in a BNML model. Pretreatment with curcumin enhanced the antileukemic activity of etoposide in BNML rats (1.57-fold tumor reduction versus etoposide alone; P<0.05) and induced apoptosis of BNML cells more efficiently than etoposide alone (1.54-fold change versus etoposide alone; P<0.05), but this treatment protected nonleukemic B-cells from apoptosis. Thus, curcumin can increase the antileukemic effect of etoposide through reactive oxygen species in sensitive myeloid leukemia cells, and it is harmless to normal human cells.
Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired ...mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer’s disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a “genetic wasteland”, and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease.
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