iTRAQ Quantitative Analysis of Multidrug Resistance Mechanisms in Human Gastric Cancer Cells

Multidrug resistance (MDR) is a major obstacle towards a successful treatment of gastric cancer. However, the mechanisms of MDR are intricate and have not been fully understood. To elucidate the molecular mechanisms of MDR in gastric cancer, we employed the proteomic approach of isobaric tags for relative and absolute quantification (iTRAQ), followed by LC-MS/MS, using the vincristine-resistant SGC7901/VCR cell line and its parental SGC7901 cell line as a model. In total, 820 unique proteins were identified and 91 proteins showed to be differentially expressed in SGC7901/VCR compared with SGC7901. Several differentially expressed proteins were further validated by western blot analysis. Furthermore, the association of MVP, one of the highly expressed proteins in SGC7901/VCR, with MDR was verified. Our study is the first application of iTRAQ technology for MDR mechanisms analysis in gastric cancer, and many of the differentially expressed proteins identified have not been linked to MDR in gastric cancer before, which showed the value of this technology in identifying differentially expressed proteins in cancer

Folate Deficiency Induces Neural Stem Cell Apoptosis by Increasing Homocysteine In Vitro

Cellular events for neural progenitor cells, such as proliferation and differentiation, are regulated by multiple intrinsic and extrinsic cell signals. Folate plays a central role in central nervous system development, so folate, as an extrinsic signal, may affect neural stem cell (NSC) proliferation and differentiation. In the present study, we investigated the effects of folate deficiency on the cell proliferation, cell apoptosis and homocysteine concentrations in NSCs. NSCs were isolated from fetal rats and identified as NSCs by their expression of immunoreactive nestin. Cell proliferation was quantitated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptotic cells were detected and confirmed by flow cytometric analysis. We measured homocysteine concentrations in NSCs by high performance liquid chromatography and detected the expression of caspase-3 by western blot method. Folate deficiency not only decreased cell proliferation, but also increased the apoptotic rate of NSCs as demonstrated by the increased expression of early apoptotic markers such as caspase-3, compared to control group (p<0.05). Furthermore, There was a statistically significant increase in homocysteine concentration during folate deficiency in NSCs (p<0.05). These data suggest that folate affects the cell proliferation, apoptosis and homocysteine generation in NSC cells

1-Metilciklopropen ublažava oštećenja mahuna tijekom skladištenja pri niskim temperaturama povećanjem učinka antioksidacijskog sustava stanične zaštite

Research background. Chilling injury is a major disorder affecting the quality of tropical and subtropical vegetables during low temperature storage. Snap bean (Phaseolus vulgaris L.) is sensitive to chilling injury. The main purpose of the present study is to investigate the alleviating effects of 1-methylcyclopropene (1-MCP) on chilling injury of snap bean. In addition, the related mechanisms were also detected from the perspective of the changes of antioxidant defense system. Experimental approach. Snap beans were exposed to different volume fractions of 1-MCP. After 24 h of treatment, snap beans were stored at 4 °C for up to 14 days. Chilling injury index, electrolyte leakage, titratable acidity and total soluble solids were determined. Contents of chlorophyll, ascorbic acid and malondialdehyde were assessed. The total antioxidant capacity, Fe(II) ion chelating capacity, scavenging capacities on free radicals and activities of antioxidant enzymes were detected. Total phenol content and activities of related metabolic enzymes were also determined. Results and conclusions. 1-MCP treatment reduced chilling injury index, electrolyte leakage rate and malondialdehyde content of snap beans. The amounts of total soluble solids, titratable acid, ascorbic acid and total chlorophyll in 1-MCP-treated snap beans were significantly higher than those of control. The snap beans treated with 1-MCP showed stronger total antioxidant capacity and metal chelating activity. The 1-MCP treatment enhanced scavenging effects of snap beans on superoxide, hydroxyl and 1,1-diphenyl-2-trinitrophenylhydrazine radicals. The activities of peroxidase, ascorbate peroxidase, superoxide dismutase and catalase in 1-MCP-treated group were higher than of control. The treatment also enhanced the accumulation of phenolic compounds in snap beans by regulating the activities of phenol-metabolizing enzymes such as shikimate dehydrogenase, phenylalanine ammonia lyase enzyme, cinnamic acid 4-hydroxylase and polyphenol oxidase. In conclusion, with the mechanism that involves the activation of enzymatic and non-enzymatic antioxidant systems, 1-MCP has the ability to avoid chilling injury of snap bean. Novelty and scientific contribution. This study gives insights into whether 1-MCP can regulate postharvest cold resistance in vegetables by enhancing the enzymatic antioxidant system and inducing the accumulation of non-enzymatic antioxidants. Considering the results, 1-MCP treatment could be an effective method to alleviate postharvest chilling injury of snap beans during low temperature storage.Pozadina istraživanja. Oštećenje ploda tijekom skladištenja pri niskim temperaturama jedan je od primarnih uzroka smanjenja kakvoće tropskog i suptropskog povrća. Grah (Phaseolus vulgaris L.) je osjetljiv na oštećenja pri niskim temperaturama. Stoga je glavna svrha ovoga rada bila ispitati ublažavajući učinak 1-metilciklopropena na oštećenja mahuna pri niskim temperaturama. Osim toga, utvrđeni su mehanizmi promjene obrambenog antioksidacijskog sustava. Eksperimentalni pristup. Mahune su izložene različitim volumnim udjelima 1-metilciklopropena tijekom 24 sata. Nakon toga su uzorci mahuna skladišteni pri 4 °C do 14 dana. Mjereni su sljedeći parametri: indeks oštećenja pri niskim temperaturama, gubitak elektrolita, titracijska kiselost i udjel ukupnih topljivih tvari. Osim toga, utvrđeni su udjeli klorofila, askorbinske kiseline i malondialdehida. Određeni su ukupni antioksidacijski učinak, sposobnost keliranja Fe(II) iona, sposobnost uklanjanja reaktivnih kisikovih spojeva i aktivnost antioksidacijskih enzima. Također su određeni ukupni udjel fenola i s njima povezana metabolička aktivnost enzima. Rezultati i zaključci. Nakon obrade 1-metilciklopropenom smanjili su se indeks oštećenja pri niskim temperaturama, gubitak elektrolita i udjel malondialdehida u mahunama. Količine ukupnih topljivih suhih tvari, titracijske kiselosti, askorbinske kiseline i ukupnog klorofila u mahunama izloženim 1-metilciklopropenu bile su znatno veće nego u kontrolnom uzorku. Tretirane mahune imale su veću ukupnu antioksidacijsku aktivnost i sposobnost keliranja metala. Obradom 1-metilciklopropenom povećala se sposobnost uklanjanja radikala superoksida, hidroksila i 1,1-difenil-2-trinitrofenilhidrazina u mahunama. Aktivnosti peroksidaze, askorbat peroksidaze, superoksid dismutaze i katalaze bile su veće u tretiranim nego u kontrolnim uzorcima. Osim toga, obradom se povećalo nakupljanje fenolnih spojeva zbog regulacije enzima koji sudjeluju u metabolizmu fenola, kao što su šikimat-dehidrogenaza, fenilalanin amonijak-liaza, p-kumarinska kiselina i polifenol-oksidaza. Možemo zaključiti da 1-metilciklopropen može spriječiti oštećenje mahuna pri niskim temperaturama aktivacijom enzimskih i neenzimskih antioksidacijskih sustava. Novina i znanstveni doprinos. Ovaj rad daje uvid u mogućnost regulacije otpornosti povrća na niske temperature tijekom skladištenja poboljšanjem enzimskog antioksidacijskog sustava pomoću 1-metilciklopropena te nakupljanjem neenzimskih antioksidanasa. Dobiveni rezultati pokazuju da bi obrada 1-metilciklopropenom mogla biti učinkovita metoda ublažavanja oštećenja pri niskim temperaturama tijekom skladištenja graha

Long-Term Nucleos(t)ide Analogues Therapy for Adults With Chronic Hepatitis B reduces the Risk of Long-Term Complications: a meta-analysis

<p>Abstract</p> <p>Background</p> <p>The effect of antiviral therapy in chronic hepatitis B (CHB) on reducing the risk of long-term complications (LTCs) remains unclear so far. To study whether long-term nucleos(t)ide analogues therapy can reduce the risk of long-term complications.</p> <p>Methods</p> <p>We searched MEDLINE, EMBASE, OVID, the Cochrane Central Register of Controlled Trials. Relative risks (RRs) of long-term complications with or without treatment were studied. Also subgroup analyses including the status of drug-resistance, HBeAg and pre-existing compensated cirrhosis were done using relative risks of long-term complications either with or without treatment or among nucleos(t)ide analogues treatment groups.</p> <p>Results</p> <p>Six eligible studies (3644 patients in all) were included. Data showed the incidence of long-term complications in treatment groups was induced by 74%(RR:0.26, 95% CI: 0.15-0.47) compared with no treatment. Whether drug-resistant happened or not during the long-term therapy, the incidence of long-term complications was still significantly induced respectively by 45%(RR: 0.55,95%CI:0.40-0.76) and 78% (RR:0.22, 95%CI: 0.13-0.36). For both different status of HBeAg and pre-existing compensated cirrhosis, there was significant lower incidence of long-term complications in treatment groups compared with no treatment, too. Moreover, among the NA treatment groups, patients with drug-resistance had 2.64 times (RR:2.64, 95%CI: 1.58-4.41) higher chance of developing to long-term complications, and patients with pre-existing compensated cirrhosis also had 3.07 times (RR:3.07, 95%CI: 1.04-9.11) higher chance of developing to long-term complications.</p> <p>Conclusions</p> <p>Long-term nucleos(t)ide analogue therapy for adults with CHB prevents or delays the development of long-term complications including decompensated cirrhosis, CHB-related death or CHB-related HCC in patients with CHB. The patients who need take antiviral drugs should receive the antiviral therapy as soon as possible.</p

Absorption, Distribution and Excretion of 14C-Probimane in Mice Bearing Lewis Lung Carcinoma

Spontaneous neoplasm metastasis, a fatalist pathological feature of cancer, is a long-evolving, multi-steps process that can now only be treated or controlled by drugs or immuno-modulators. Probimane (Pro), as a representative of the well-known class of antimetastatic agents ‘Bisdioxopiperazine compounds (Biz)’, is systematically studied for its absorption, distribution and excretion in mice bearing Lewis lung carcinoma by a radioactivity-detective method in this investigation. It is found that the 14C-Pro concentrations in different normal organs of mice at 2 hrs are very high and dramatically declined at 24 and 48 hrs. However, Pro concentrations in metastatic foci are slightly changed at the same time. Almost no change of Pro concentrations is observed in pulmonary metastatic nodules within 48 hrs. This evidence can be used to explain the characteristics of good metastatic inhibition by Biz compounds. The radioactivity in brain is relatively low because Pro can hardly penetrate into the blood-brain-barrier to eliminate brain tumors. The excretion of 14C-Pro is observed at the same ratios from both urine and feces and also at constant rates. These data are much useful for better understanding of the general pharmacological characters and possible antimetastatic mechanisms of actions of probimane and other Biz compounds from a new perspective and research angles

Different Spontaneous Pulmonary Metastasis Inhibitions against Lewis Lung Carcinoma in Mice by Bisdioxopiperazine Compounds of Different Treatment Schedules

Spontaneous neoplasm metastasis, a fatalist pathological feature of cancer, is a long-evolving, multi-steps process that can now only be treated or controlled by drugs or immuno-modulators. As we have previously hypothesized, each drug or immuno-modulator might act differently within various stages of a metastasis. Therefore any researches helping to determine these differences will be beneficial for updating therapeutics for metastasis. In this work, we have testified this hypothesis by using a series of well-known anti-metastatic agents – Bisdioxopiperazine compounds

Synergistic anti-atherosclerotic effect of Yerba Maté (Illex Paraguariensis) polyphenols and Lox-1 silencing in foam cell model

Purpose: To elucidate the anti-atherosclerotic effect of Yerba Mate polyphenols (MP) as well as the anti-atherosclerotic effect of a combination of MP and silencing of lectin-like oxidized low-density lipoprotein receptor-1 interference group (LOX)-1.Methods: The anti-atherosclerotic effects of control group (CG), simvastatin group (SG), MP group (MP), LOX-1 interference group (LOX) and MP + LOX-1 interference group (MP-LOX) were determined using Oil Red O staining, enzyme-linked immunosorbent assay (ELISA) and Western blot assay.Results: The levels of foam cells, intracellular lipids, viz, total cholesterol (TC), free cholesterol (FC), cholesterol ester (CE) and acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1); LOX-1, inflammation (TNF-alpha, IL-6 and pNF-κB/NF-κB); adhesion molecular status (ICAM-1 and VCAM-1), and monocyte chemotactic protein-1 in SG and in MP, LOX and MP-LOX groups were significantly decreased, when compared with CG (p &lt; 0.01). The levels of these parameters were much lower in MPLOX group than in SG (p &lt; 0.01). However, they were synergistically reduced in MP-LOX group, relative to MP group or LOX group (p &lt; 0.01). Combination of LOX-1 gene silencing with MP produced synergistic anti-atherosclerotic effect which was reflected in decreases in foam cell formation, intracellular lipids, inflammatory status, adhesion molecular status, and MCP-1-mediated migration and infiltration of macrophages in foam cells.Conclusion: The synergistic anti-atherosclerotic effects of MP and LOX-1 gene silencing may be potential tools for development of anti-atherosclerotic agents