Cancer is a major health problem in many parts of the world. Conventional anticancer treatments are painful, expensive, and unsafe. Therefore, demand is increasing for cancer treatments ...preferentially in the form of functional foods or nutritional supplements. Kefir, a traditional fermented milk dairy product, has significant antimutagenic and antitumor properties. This research addresses the hypothesis that kefir's anticancer properties are affected by fermentation conditions. Initially, kefir extracts prepared under standard conditions were screened against 7 cancer cell lines using the tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Colon cancer and chronic myelogenous leukemia cells were found to be most susceptible to kefir extracts. Subsequently, a factorial design was implemented to assess the effects of 3 fermentation times (24, 48, and 72 h), 3 kefir-to-milk ratios (2, 5, and 10% wt/vol), and 3 fermentation temperatures (4, 25, and 40°C) on kefir's anticancer properties. Remarkably, exploration of the fermentation conditions allowed the anticancer properties of kefir to be enhanced by 5- to 8-fold against susceptible cell lines. Overall, these results demonstrate the possibility of optimizing the anticancer properties of kefir as a functional food in cancer therapy.
Hypoxia plays a critical role in the tumor microenvironment by affecting cellular proliferation, metabolism, apoptosis, DNA repair, and chemoresistance. Since hypoxia provokes a distinct shift of ...microRNA, it is important to illustrate the relative contribution of each hypoxamiR to cancer progression.
The present study aims to shed light on the hypoxamiRs that are involved in pancreatic and breast cancer progression to highlight novel targets for the development of new therapies.
For 20 cycles, MCF7 breast cancer cells and PANC-1 pancreatic cancer cells were subjected to chronic cyclic hypoxia, which consisted of 72 hours of hypoxia followed by 24 hours of reoxygenation. After 10 and 20 cycles of hypoxia, miRNA expression alterations were profiled using RT-PCR array and further analyzed using a visual analytics platform. The MTT cell proliferation assay was used to determine hypoxic cells' chemoresistance to doxorubicin.
Under chronic cyclic hypoxia, hypoxic PANC-1 cells have a comparable doubling time with their normoxic counterparts, whereas hypoxic MCF7 cells show a massive increase in doubling time when compared to their normoxic counterparts. Both hypoxic cell lines developed EMT-like phenotypes as well as doxorubicin resistance. According to the findings of miRNet, 6 and 10 miRNAs were shown to play an important role in enriching six hallmarks of pancreatic cancer in the 10th and 20th cycles of hypoxia, respectively, while 7 and 11 miRNAs were shown to play an important role in enriching the four hallmarks of breast cancer in the 10th and 20th cycles of hypoxia, respectively.
miR-221, miR-21, miR-155, and miR-34 were found to be involved in the potentiation of hypoxic PANC-1 hallmarks at both the 10th and 20th cycles, while miR-93, miR-20a, miR-15, and miR-17 were found to be involved in the potentiation of hypoxic MCF7 hallmarks at both the 10th and 20th cycles. This variation in miRNA expression was also connected to the emergence of an EMT-like phenotype, alterations in proliferation rates, and doxorubicin resistance. The chemosensitivity results revealed that chronic cyclic hypoxia is critical in the formation of chemoresistant phenotypes in pancreatic and breast cancer cells. miR-181a and let-7e expression disparities in PANC1, as well as miR-93, miR-34, and miR-27 expression disparities in MCF7, may be associated with the formation of chemoresistant MCF7 and PANC-1 cells following 20 cycles of chronic cyclic hypoxia. Indeed, further research is needed since the particular mechanisms that govern these processes are unknown.
Hypoxia plays a significant role in tumor progression and aggressiveness and implicated in resistance to radiotherapy and chemotherapy. This study aims to characterize the changes in gene expression ...associated with chronic hypoxia in MCF7 breast cancer cell line and identify a possible biomarker for hypoxia in breast cancer. Breast cancer cells (MCF7) were exposed to 8-hour hypoxic episodes (<1% oxygen) three times a week for a total of 38 episodes. Gene expression changes were profiled using RT- PCR array after 19 and 38 episodes of hypoxia and compared to normoxic cells. Chemoresistance of hypoxic cells toward doxorubicin was assessed using MTT cell proliferation assay. Marked gene expression changes were indentified after 19 and 38 episodes of hypoxia. Only few changes were common in both stages with most genes rebounding at the level of 38 episodes. A notable gene (HNF4A) has been up-regulated by 2 folds after 19 hypoxic shots and further up-regulated by 6.43 folds after 38 hypoxic shots. The half maximal inhibitory concentration (IC50) of doxorubicin in MCF7 cells has increased in a trend proportional to the number of hypoxic episodes then totally rebounded after incubation under normoxia for 3weeks. This study provides evidence that exposing cells to prolonged periods of hypoxia (weeks) results in different expression changes than those induced by short-term hypoxia (less than 72h).
•Breast cancer cells (MCF7) were exposed to 8-hour hypoxic episodes three times a week for a total of 38 episodes.•HNF4A has been up-regulated by 2 folds after 19 hypoxic shots and further up-regulated by 6.43 folds after 38 hypoxic shots.•The IC50 of doxorubicin in MCF7 cells has increased in a trend proportional to the number of hypoxic episodes.•The resistance toward doxorubicin totally rebounded after incubation under normoxia for 3 weeks.
The P-glycoprotein (P-gp) efflux pump has an important role as a natural detoxification system in many types of normal and cancer cells. P-gp is implicated in multiple drug resistance (MDR) exhibited ...by several types of cancer against a multitude of anticancer chemotherapeutic agents, and therefore, it is clinically validated target for cancer therapy. Accordingly, in this study we combined exhaustive pharmacophore modeling and quantitative structure-activity relationship (QSAR) analysis to explore the structural requirements for potent P-gp inhibitors employing 130 known P-gp ligands. Genetic function algorithm (GFA) coupled with k nearest neighbor (kNN) or multiple linear regression (MLR) analyses were employed to build self-consistent and predictive QSAR models based on optimal combinations of pharmacophores and physicochemical descriptors. Successful pharmacophores were complemented with exclusion spheres to optimize their receiver operating characteristic curve (ROC) profiles. Optimal QSAR models and their associated pharmacophore hypotheses were validated by identification and experimental evaluation of new promising P-gp inhibitory leads retrieved from the National Cancer Institute (NCI) structural database. Several potent hits were captured. The most potent hit decreased the IC50 of doxorubicin from 0.906 to 0.190 μM on doxorubicin resistant MCF7 cell-line.
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•130 P-glycoprotein inhibitors were collected.•Their pharmacophoric space was extensively explored.•MLR- and kNN-based QSAR analysis were employed to select optimal pharmacophore models.•Optimal pharmacophores were complemented with exclusion constrains as 3D queries to mine for new active hits.•Three hits exhibited potent P-gp inhibitory properties.
Metformin is a biguanide that exhibits antidiabetic, anticarcinogenic, and anti-inflammatory properties. Despite well-known pancreatic protective effects, metformin's influence on pancreatic islet ...β-cell is yet considerably unknown. Protecting the functional insulin-producing β-cells in the pancreas is a key therapeutic challenge in patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM).
The current study aimed to analyze the protective effects of metformin on streptozocin- induced diabetic rats in T1DM in hepatic tissues.
In the present study, male Wistar rats (n=24) were randomly assigned into 2 groups (n=12 for each control and test), and metformin (100 mg/kg/day) was given for 7 weeks. Afterward, diabetes was induced by streptozocin (STZ) at a single dose of 150 mg/kg. Blood glucose was examined daily before and after STZ induction. The animals were euthanized by cervical dislocation 5 days after streptozocin injection, after which liver and pancreas were harvested from each rat.
The biochemical analyses revealed that metformin resulted in significantly reduced plasma glucose levels and higher pancreatic insulin levels in the test group. Using a restrictive cut-off of at least 2-FC and an adjusted p-value (q-value) of ≤0.05, a sum of 747 genes for the metformin group were shown to be differentially regulated compared to controls (320 Down and 427 Up), by which they were obtained from the liver. Furthermore, the evidence is attained that metformin may hinder the loss of critical β-cells by reducing inflammatory and apoptosis signaling, promoting fatty acid β-oxidation, and inducing metabolism.
Collectively, this study has demonstrated a decrease in blood glucose levels and a rise in insulin-levels and thus consequent prophylactic effects in metformin-given STZ-induced diabetic rats.
Asthma and allergic rhinitis are respiratory diseases with a significant global burden. Forkhead box O3 (FOXO3) is a gene involved in the etiology of a number of respiratory diseases. The objective ...of this study is to assess the association of rs13217795, an intronic FOXO3 single-nucleotide polymorphism, with asthma and allergic rhinitis.
In this case-case-control genetic association study, genotyping was conducted using the PCR-RFLP method. Genotype-based associations were investigated under the general, recessive, and dominant models of disease penetrance using binomial logistic regression; and, allele-based associations were tested using Pearson's chi-squared test.
The final study population consisted of 94 controls, 124 asthmatics, and 110 allergic rhinitis patients. The general and recessive models of disease penetrance were statistically significant for both case-control comparisons. Under the general model, the odds of the asthma phenotype were 1.46 (0.64 to 3.34) and 3.42 (1.37 to 8.57) times higher in heterozygotes and derived allele homozygotes, respectively, compared to ancestral allele homozygotes. The corresponding odds ratios for the allergic rhinitis phenotype were 1.05 (0.46 to 2.40) and 2.35 (0.96 to 5.73), respectively. The dominant model of disease penetrance was not statistically significant. The minor allele in all study groups was the ancestral allele, with a frequency of 0.49 in controls. There was no deviation from Hardy-Weinberg equilibrium in controls. Both case-control allele-based associations were statistically significant.
Herein we present the first report of the association between rs13217795 and allergic rhinitis, and the first independent verification of the association between rs13217795 and asthma. Marker selection in future genetic association studies of asthma and allergic rhinitis should include functional polymorphisms in linkage disequilibrium with rs13217795.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Bcl-2 is an anti-apoptotic protein involved in cancer resistance to cytotoxic therapies making it an interesting target for inhibitors design. Towards this end, we implemented an elaborated ...ligand-based computational workflow that combines exhaustive pharmacophore modeling and quantitative structure-activity relationship (QSAR) analysis to explore the structural features required for potent Bcl-2 inhibitors employing 98 known Bcl-2 inhibitors. Genetic function algorithm (GFA) coupled with k nearest neighbor (kNN) or multiple linear regression (MLR) analyses were employed to generate predictive QSAR models based on optimal combinations of pharmacophores and physicochemical descriptors. The optimal QSAR-selected pharmacophore models were validated by receiver operating characteristic (ROC) curve analysis and by comparison with crystallographic structures of known inhibitors co-crystallized within Bcl-2 binding pocket. Optimal QSAR models and their associated pharmacophore hypotheses were validated by identification and experimental evaluation of new selective cytotoxic compounds against Bcl-2 expressing cancer cells. The hits were retrieved from the National Cancer Institute (NCI) structural database. Several potent hits were captured. The most potent hits illustrated IC50 values of 4.2 and 2.60 μM against MDA-MB-231 cancer cell-line.
•98 Bcl-2 inhibitors were collected.•Their pharmacophoric space was extensively explored.•MLR- and kNN-based QSAR analysis were employed to select optimal pharmacophore models.•Optimal pharmacophores were used as 3D query to mine for new active hits.•The most potent hits illustrated micromolar IC50s against MDA-MB-231 cell-line.
Development of resistance against cancer therapeutic agents is a common problem in cancer management. Trastuzumab resistance is one of the challenges in management of HER-2-positive breast cancer ...patients resulting in breast cancer progression, metastasis, and patient poor outcome. The aim of this study is to determine the alteration in gene expression in response to Trastuzumab resistance after long-term exposure to Trastuzumab. The Trastuzumab-resistant MDA-MB-453 (MDA-MB-453/TR) cell line was developed by exposing cells to 10μM Trastuzumab continuously for 6months. Sensitivity toward Trastuzumab was tested using cell viability assays. The acquisition of an epithelial-to mesenchymal transition (EMT) phenotype was also observed in parallel with the development of resistance. Based on the real-time-based PCR array technology, several genes were altered affecting multiple networks. The most up-regulated genes were TGF-β1 and EGF, and IGFBP-3. These genes are known to have a critical role in Trastuzumab resistance in breast cancer cell lines and/or in the acquisition of EMT. They are also recognized for their role in cancer progression and metastasis. These alterations indicate that the development of Trastuzumab resistance is multifactorial and involves a development of a mesenchymal like phenotype.
•The Trastuzumab resistant in MDA-MB-453 is multi factorial.•Morphological change toward EMT was observed.•The most up-regulated genes were IGFBP-3, TGF-β1 and EGF.•IGFBP-3, TGF-β1 and EGF may have a critical role in Trastuzumab resistance.
Breast cancer is the most common type of cancer among females. Hypoxia mediates cancer hallmarks and results from reduced oxygen level due to irregularities in tumor vascularization or when the tumor ...size prevents oxygen diffusion and triggers angiogenesis to compensate for low oxygen. Cancer stem cells (CSCs) are a rare subpopulation, able to self-renew and to give rise to tumor-initiating cells. It is proposed that CSCs' secretions help to recruit endothelial cells via angiogenic factors to establish tumor vascularization. In the tumor microenvironment, the effect of hypoxia on CSCs and the impact of their secretions on triggering angiogenesis and tumor vascularization remain questionable. In this study, three-dimensional (3D) CSCs derived from MCF-7 were directly exposed to repetitive long-term cycles of hypoxia to assess its effect on CSCs and then to evaluate the role of the hypoxic CSCs' (CSCs
) secretions in angiogenesis using (HUVECs) as a model for tumor neovascularization response.
CSCs derived from MCF-7 cell-line were expanded under repetitive, strictly optimized, long-term/continuous and intermittent hypoxic shots for almost four months to assess hypoxic effect on CSCs, sorted based on CD44
/CD24
biomarkers. Hypoxic phenotype of CSCs
was evaluated by assessing the acquired chemoresistance using MTT assay and elevated stemness properties were assessed by flow cytometry. To evaluate the effect of the secretions from CSCs
on angiogenesis, HUVECs were exposed to CSCs
conditioned-medium (CdM)-in which CSCs had been previously grown-to mimic the tumor microenvironment and to assess the effect of the secretions from CSCs
on the HUVECs' capability of tube formation, migration and wound healing. Additionally, co-culture of CSCs
with HUVECs was performed.
CSCs
acquired higher chemoresistance, increased stemness properties and obtained greater propagation, migration, and wound healing capacities, when compared to CSCs in normoxic condition (CSCs
). HUVECs' tube formation and migration abilities were mediated by hypoxic (CSCs) conditioned media (CdM).
This study demonstrates that chemoresistant and migrational properties of CSCs are enhanced under hypoxia to a certain extent. The microenvironment of CSCs
contributes to tumor angiogenesis and migration. Hypoxia is a key player in tumor angiogenesis mediated by CSCs.
The aim of this study was to characterize cycling hypoxia-induced changes in the expression of metabolism-related genes in the pancreatic cancer cell line PANC1. PANC1 cells were exposed to either 7 ...h cycles of hypoxia every other day for 20 cycles (cyclic acute hypoxia), or for 72 h cycles of hypoxia once a week for 5 cycles (cyclic chronic hypoxia). Changes in gene expression were profiled using reverse transcription-quantitative PCR and compared to cells cultured under normoxic conditions. Western blotting analysis confirmed upregulation of HIF1-alpha, glucose-6-phosphate isomerase, and ribokinase at the mRNA level. Upregulation in genes encoding enzymes involved in glycolysis was greater in cells cultured under cyclic acute hypoxia compared with cells cultured under chronic hypoxia including hexokinase2 and phosphoglyc-erate kinase 1. Genes encoding the pentose phosphate pathway (PPP) enzymes (transketolase and transaldolase) were upregulated to a similar degree. The expression of genes encoding pyruvate dehydrogenases that block pyru-vate flow to the TCA cycle was significantly upregulated. Thus, exposure of PANC1 cells to acute hypoxia resulted in the upregulation of genes that shift the metabolism of cells towards glycolysis and the pentose phosphate pathway (PPP) in adaptation to hypoxic stress. Key words: cyclic hypoxia, gene expression, HIF1-alpha, glucose-6-phosphate isomerase, ribokinase, doxorubicin
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