Long-term exposure to arsenic in drinking water leads to myocardial damage by oxidative stress and reduction in NO.

Chronic arsenic exposure causes myocardial damage. The aim of this study is to investigate if oxidative stress and reduction in NO is involved in the myocardial damage induced by arsenic in drinking water. Rats were divided into a control group and different doses of sodium arsenite. With increasing sodium arsenite concentrations in drinking water, localised inflammatory foci and necrotic myocardial tissues were gradually observed. Compared to the control group, the activities and gene expression of antioxidant enzymes in arsenic-exposed rats decreased. NO content and the NOS activity as well as the expression of NOS mRNA in the myocardial tissue of exposed rats, decreased, and the extracellular NO content of cardiomyocytes treated with sodium arsenite also decreased. The rate of cell apoptosis induced by sodium arsenite decreased after treatment with sodium nitroprusside (an NO donor). In conclusion, arsenic exposure in drinking water can lead to myocardial injury and cardiomyocyte apoptosis through oxidative stress and a reduction in NO content.

The Biological and Molecular Function of LINC00665 in Human Cancers.

Long non-coding RNAs (lncRNAs) are more than 200 nucleotides in length and are implicated in the development of human cancers, without protein-coding function. Mounting evidence indicates that cancer initiation and progression are triggered by lncRNA dysregulation. Recently, a growing number of studies have found that LINC00665, a long intergenic non-protein coding RNA, may be associated with various cancers, including gastrointestinal tumors, gynecological tumors, and respiratory neoplasms. LINC00665 was reported to be significantly dysregulated in cancers and has an important clinical association. It participates in cell proliferation, migration, invasion, and apoptosis through different biological pathways. In this review, we summarize the current findings on LINC00665, including its biological roles and molecular mechanisms in various cancers. LINC00665 may be a potential prognostic biomarker and novel therapeutic target for cancers.

Endoplasmic reticulum stress pathway mediates T-2 toxin-induced chondrocyte apoptosis.

T-2 toxin leads to chondrocyte apoptosis and excessive extracellular matrix degradation. The aim of this study is to investigate if endoplasmic reticulum stress (ERS) - initiated apoptosis is involved in the chondrocyte damage induced by T-2 toxin. In vivo, rats were divided into a control group, T-2 toxin 200 ng/g BW/d group, the protein levels of GRP78, CHOP, and caspase-12 were detected using immunohistochemistry in articular cartilage tissues. In vitro, C28/I2 and ATDC5 chondrocytes were treated with various concentrations of T-2 toxin. For the salubrinal protection assay, cells were pretreated with 20 µM salubrinal for 1 h, and treated with and without T-2 toxin for 24 h. The cell viability was determined using the MTT assay; and the cell apoptosis was determined using the Flow Cytometry Assay; the mRNA and protein levels of the ERS markers and ECM were determined using RT-PCR and western blotting. This study found that the expressions of GRP78, CHOP, and caspase-12 is higher in T-2 toxin group than in control group both in vivo and in vitro, and the T-2 toxin administration promoted chondrocyte apoptosis, suppressed matrix synthesis, and accelerated cellular catabolism via the ERS signaling pathway. In addition, this study found that salubrinal prevented chondrocyte injury by inhibiting ERS-mediated apoptosis via the PERK-eIF2α-ATF4-CHOP signaling pathway. Collectively, this study provides a new clue to elucidate the mechanism of T-2 toxin-induced chondrocyte damage, and presents a novel therapeutic possibility of salubrinal for Osteoarthropathy such as osteoarthritis (OA) and Kaschin-Beck disease (KBD).

Estrogen augmented visceral pain and colonic neuron modulation in a double-hit model of prenatal and adult stress.

BACKGROUND: Chronic stress during pregnancy may increase visceral hyperalgesia of offspring in a sex-dependent way. Combining adult stress in offspring will increase this sensitivity. Based on the evidence implicating estrogen in exacerbating visceral hypersensitivity in female rodents in preclinical models, we predicted that chronic prenatal stress (CPS) + chronic adult stress (CAS) will maximize visceral hyperalgesia; and that estrogen plays an important role in colonic hyperalgesia. AIM: The aim was to illuminate the role of estrogen in colonic hyperalgesia and its underlying mechanisms. METHODS: We established a CPS plus CAS rodent model in which the balloon was used to distend the colorectum. The single-fiber recording in vivo and patch clamp experiments in vitro were used to monitor the colonic neuron's activity. The reverse transcription-polymerase chain reaction, western blot, and immunofluorescence were used to study the effects of CPS and CAS on colon primary afferent sensitivity. We used ovariectomy and letrozole to reduce estrogen levels of female rats respectively in order to assess the role of estrogen in female-specific enhanced primary afferent sensitization. RESULTS: Spontaneous activity and single fiber activity were significantly greater in females than in males. The enhanced sensitization in female rats mainly came from low-threshold neurons. CPS significantly increased single-unit afferent fiber activity in L6-S2 dorsal roots in response. Activity was further enhanced by CAS. In addition, the excitability of colon-projecting dorsal root ganglion (DRG) neurons increased in CPS + CAS rats and was associated with a decrease in transient A-type K+ currents. Compared with ovariectomy, treatment with the aromatase inhibitor letrozole significantly reduced estrogen levels in female rats, confirming the gender difference. Moreover, mice treated with letrozole had decreased colonic DRG neuron excitability. The intrathecal infusion of estrogen increased brain-derived neurotrophic factor (BDNF) protein levels and contributed to the response to visceral pain. Western blotting showed that nerve growth factor protein was upregulated in CPS + CAS mice. CONCLUSION: This study adds to the evidence that estrogen-dependent sensitization of primary afferent colon neurons is involved in the development of chronic stress-induced visceral hypersensitivity in female rats.

Integrin α2ß1 is involved in T-2 toxin-induced decrease of type II collagen in C28/I2 chondrocytes.

The T-2 toxin exerts a variety of toxic effects on both experimental animals and humans. The integrin family plays a major role in mediating cell-ECM interactions. Therefore, the present study aimed to investigate the involvement of integrin α2ß1 in T-2 toxin-induced C28/I2 chondrocyte damage. The pathological damage of articular cartilage injury induced by T-2 toxin was observed by H&E staining. The expression levels of collagen 2 and MMP-13 (Matrix metalloproteinases 13) were detected using immunohistochemistry in articular cartilage tissues and western blotting in the cells. The blocking effect of integrin α2ß1 inhibitor on T-2 toxin-induced chondrocyte matrix degradation was examined by western blotting. Further, the effect of integrin α2ß1 inhibitor on T-2 toxin-induced chondrocyte apoptosis was analyzed. About 100 ng/g body weight (BW)/day T-2 toxin was fed to Sprague-Dawley (SD) rats, T-2 toxin treatment (0, 6, 12, and 24 ng/mL) induced C28/I2 chondrocytes. Both in vivo and in vitro, chondrocyte survival was inhibited, and the production of type II collagen was significantly reduced (p < 0.05). However, the level of MMP-13 was up-regulated (p < 0.05). Matrix degradation was effectively blocked after the pre-treatment by integrin α2ß1 inhibitor (p < 0.05). Conclusively, Integrin α2ß1 is a critical signaling pathway for communication between cells and the extracellular matrix, the present study provides a new clue to elucidate the mechanism of T-2 toxin-induced chondrocyte damage.

Gene Expression Profile of Hypertrophic Chondrocytes Treated with H2O2: A Preliminary Investigation.

Objective To identify the osteogenesis genes whose expression is altered in hypertrophic chondrocytes treated with H2O2. Methods Murine chondrogenitor cells (ATDC5) were differentiated into hypertrophic chondrocytes by Insulin-Transferrin-Selenium (ITS) treatment, and then treated with H2O2. Suitable conditions (concentration, time) were determined by using the MTT assay. After total RNA isolation and cDNA synthesis, the levels of 84 genes were determined using the PCR array, whereas quantitative RT-PCR was carried out to validate the PCR array data. Result We identified 9 up-regulated genes and 12 down-regulated genes, encoding proteins with various functions, such as collagen proteins, transcription factors, proteins involved in skeletal development and bone mineral metabolism, as well as cell adhesion molecules. Quantitative RT-PCR confirmed the altered expression of 5 down-regulated genes (Smad2, Smad4, transforming growth factor $\beta$ receptor 1, transforming growth factor $\beta$ receptor 3, and matrix metalloproteinase 10). Conclusions H2O2 significantly changed the expression of several genes involved in a variety of biological functions. Because of the link between oxidative damage and Kashin-Beck disease, these genes may also be involved in the deep-zone necrosis of the cartilage observed in Kashin-Beck disease.

SP600125 blocks the proteolysis of cytoskeletal proteins in apoptosis induced by gas signaling molecule (NO) via decreasing the activation of caspase-3 in rabbit chondrocytes.

NO plays a key role in the pathological mechanisms of articular diseases. As cytoskeletal proteins are responsible for the polymerization, stabilization, and dynamics of the cytoskeleton network, we investigated whether cytoskeletal proteins are the intracellular pathological targets of NO. We aimed at clarifying whether the cytoskeleton perturbations involved in apoptosis are induced in rabbit articular chondrocytes by NO, which can be liberated by sodium nitroprusside (SNP) treatment. The first passage rabbit articular chondrocytes were cultured as monolayer for the experiments, and the effects of NO were tested in the presence of JNK-specific inhibitor, SP600125. SNP treatment of cultured chondrocytes caused significant apoptosis in a concentration-dependent manner (time and dose), as evaluated by TUNEL assay and Annexin V flow cytometry, while the apoptosis was reduced by the SP600125 addition 30 min before SNP treatment. Besides, SP600125 decreased significantly the protein expression of total caspase-3 and the intracellular gene expression of caspase-3, measured by Western blot analysis and PCR. SP600125 also increased the cytoskeletal protein expressions. These results suggested that JNK pathway plays a critical role in the NO-induced chondrocyte apoptosis, and SP600125 treatment blocks the dissolution of the cytoskeletal proteins via activation of caspase-3 pathways.

CaMKII-mediated Beclin 1 phosphorylation regulates autophagy that promotes degradation of Id and neuroblastoma cell differentiation.

Autophagy is a degradative pathway that delivers cellular components to the lysosome for degradation. The role of autophagy in cell differentiation is poorly understood. Here we show that CaMKII can directly phosphorylate Beclin 1 at Ser90 to promote K63-linked ubiquitination of Beclin 1 and activation of autophagy. Meanwhile, CaMKII can also promote K63-linked ubiquitination of inhibitor of differentiation 1/2 (Id-1/2) by catalyzing phosphorylation of Id proteins and recruiting TRAF-6. Ubiquitinated Id-1/Id-2 can then bind to p62 and be transported to autolysosomes for degradation. Id degradation promotes the differentiation of neuroblastoma cells and reduces the proportion of stem-like cells. Our study proposes a mechanism by which autophagic degradation of Id proteins can regulate cell differentiation. This suggests that targeting of CaMKII and the regulation of autophagic degradation of Id may be an effective therapeutic strategy to induce cell differentiation in neuroblastoma.

Increased Chondrocyte Apoptosis in Kashin-Beck Disease and Rats Induced by T-2 Toxin and Selenium Deficiency.

OBJECTIVE: To investigate chondrocyte apoptosis and the expression of biochemical markers associated with apoptosis in Kashin-Beck disease (KBD) and in an established T-2 toxin- and selenium (Se) deficiency-induced rat model. METHODS: Cartilages were collected from the hand phalanges of five patients with KBD and five healthy children. Sprague-Dawley rats were administered a selenium-deficient diet for 4 weeks prior to T-2 toxin exposure. The apoptotic chondrocytes were observed by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Caspase-3, p53, Bcl-2, and Bax proteins in the cartilages were visualized by immunohistochemistry, their protein levels were determined by Western blotting, and mRNA levels were determined by real-time reverse transcription polymerase chain reaction. RESULTS: Increased chondrocyte apoptosis was observed in the cartilages of children with KBD. Increased apoptotic and caspase-3-stained cells were observed in the cartilages of rats fed with normal and Se-deficient diets plus T-2 toxin exposure compared to those in rats fed with normal and Se-deficient diets. Caspase-3, p53, and Bax proteins and mRNA levels were higher, whereas Bcl-2 levels were lower in rats fed with normal or Se-deficiency diets supplemented with T-2 toxin than the corresponding levels in rats fed with normal diet. CONCLUSION: T-2 toxin under a selenium-deficient nutritional status induces chondrocyte death, which emphasizes the role of chondrocyte apoptosis in cartilage damage and progression of KBD.

[Expression of Proteus mirabilis polyphosphate kinase and preparation of its polyclonal antibodies].

OBJECTIVE: To express and purify polyphosphate kinase (PPK) from Proteus mirabilis and prepare the polyclonal antibody against PPK. METHODS: The antigenicity and hydrophobicity of PPK were analyzed using software. The N-terminal conservative sequence containing 309 amino acids was selected as the target peptide, and its corresponding gene sequence with modification based on prokaryotic cells-preferred codon was synthesized and inserted into plasmid pET28b(+). The constructed recombinant plasmid was transformed into Escherichia coli BL21 (DE3) and induced with IPTG. The expressed fusion protein was purified using Ni-affinity chromatography. The purified protein was injected along with adjuvant in rabbits to prepare the polyclonal antibodies against PPK. RESULTS AND CONCLUSION: PPK fusion protein expressed by E. coli was purified successfully using Ni-affinity chromatography. ELISA result demonstrated that the harvested rabbit anti-sera against PPK had a high titer of 1:512 000, and Western blotting showed a good specificity of the antibody, which can be used further study of the role of PPK in the pathogenesis of Proteus mirabilis infection.

SS31, a Small Molecule Antioxidant Peptide, Attenuates ß-Amyloid Elevation, Mitochondrial/Synaptic Deterioration and Cognitive Deficit in SAMP8 Mice.

Mitochondrial dysfunction, oxidative stress and ß -amyloid (Aß) formation are thought to cause neuronal and synaptic degeneration underlying cognitive decline in Alzheimer's disease (AD). The senescence-accelerated mouse-prone 8 (SAMP8) mice have been used as an animal model for mechanistic and translational research for AD. In the present study we characterized mitochondrial and synaptic alterations in SAMP8 mice relative to SAMR1control mice and explored a protective effect of the small molecule peptide SS31, a cell membrane penetrant antioxidant, on mitochondrial and synaptic protein integrity as well as cognitive performance. Electron microscopic analysis revealed mitochondrial/synaptic deterioration in 10 months-old SAMP8 relative to SAMR1 mice, with the changes in the former rescued following 8 weeks treatment with SS31 (5 mg/kg/day, i.p.). Elevation of Aß42, mitochondrial fission protein (DLP1, Fis1) and matrix protein cyclophilin D (CypD), and reductions of mitochondrial fusion protein (Mfn2) and synaptic (i.e., synaptophysin, postsynaptic density protein 95 and growth associated protein 43) proteins, were detected in hippocampal lysates in SAMP8 mice relative to SAMR1. The above altered protein expressions in the SAMP8 mouse brain were restored with the SS31 treatment. Moreover, the SS31 treatment rescued learning and memory deficits detected in 10 month-old SAMP8 mice. Together, the findings suggest that this mitochondria-targeting antioxidant peptide may be of potential utility for AD therapy, with its pharmacological efficacy involves lowering of central Aß levels and protection of mitochondrial homeostasis and synaptic integrity, which may help slow down cognitive decline.

ATM-mediated PTEN phosphorylation promotes PTEN nuclear translocation and autophagy in response to DNA-damaging agents in cancer cells.

PTEN (phosphatase and tensin homolog), a tumor suppressor frequently mutated in human cancer, has various cytoplasmic and nuclear functions. PTEN translocates to the nucleus from the cytoplasm in response to oxidative stress. However, the mechanism and function of the translocation are not completely understood. In this study, topotecan (TPT), a topoisomerase I inhibitor, and cisplatin (CDDP) were employed to induce DNA damage. The results indicate that TPT or CDDP activates ATM (ATM serine/threonine kinase), which phosphorylates PTEN at serine 113 and further regulates PTEN nuclear translocation in A549 and HeLa cells. After nuclear translocation, PTEN induces autophagy, in association with the activation of the p-JUN-SESN2/AMPK pathway, in response to TPT. These results identify PTEN phosphorylation by ATM as essential for PTEN nuclear translocation and the subsequent induction of autophagy in response to DNA damage.

[Role of JNK signaling pathway in chondrocyte apoptosis induced by nitric oxide].

OBJECTIVE: To study the role of c-jun N-terminal kinase (JNK) signaling pathway in chondrocyte apoptosis induced by nitric oxide (NO) using NO donor sodium nitroprusside (SNP) and JNK inhibitor SP600125. METHODS: Articular chondrocytes were separated from New Zealand rabbits aged 3 weeks by mechanical digestion and enzyme digestion and identified by toluidine blue staining, and then the chondrocytes were treated with SNP and SP600125 for 24 h. The cell apoptosis was evaluated by Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) flow cytometry and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL), and the expression levels of nuclear factor-kappa B (NF-κB) p65 and p53 were measured by western blot. RESULTS: Compared with those in control group, the early apoptotic rate of SNP-treated chondrocytes increased as the concentration of SNProse, exhibiting a concentration dependency (P < 0.05), and the expression levels of NF-κB p65 and p53 also increased (P < 0.05); JNK inhibitor SP600125 inhibited these increases (P < 0.05). CONCLUSION: JNK signaling pathway plays an important role in NO-induced chondrocyte apoptosis. JNK inhibitor SP600125 can reduce NO-induced apoptosis and expression of NF-κB p65 and p53 in articular chondrocytes of rabbits in a concentration-dependent manner.

Protective effects of selenium on oxidative damage and oxidative stress related gene expression in rat liver under chronic poisoning of arsenic.

Arsenic (As) is a toxic metalloid existing widely in the environment, and chronic exposure to it through contaminated drinking water has become a global problem of public health. The present study focused on the protective effects of selenium on oxidative damage of chronic arsenic poisoning in rat liver. Rats were divided into four groups at random and given designed treatments for 20 weeks. The oxidative damage of liver tissue was evaluated by lipid peroxidation and antioxidant enzymes. Oxidative stress related genes were detected to reflect the liver stress state at the molecular level. Compared to the control and Na2SeO3 groups, the MDA content in liver tissue was decreased and the activities of antioxidant enzymes were increased in the Na2SeO3 intervention group. The mRNA levels of SOD1, CAT, GPx and Txnrd1 were increased significantly (P<0.05) in the combined Na2SeO3+NaAsO2 treatment group. The expressions of HSP70 and HO-1 were significantly (P<0.05) increased in the NaAsO2 group and reduced in the combined treatment group. The results indicate that long-term intake of NaAsO2 causes oxidative damage in the rat liver, and Na2SeO3 protects liver cells by adjusting the expression of oxidative stress related genes to improve the activities of antioxidant enzymes.

Histopathology of chondronecrosis development in knee articular cartilage in a rat model of Kashin-Beck disease using T-2 toxin and selenium deficiency conditions.

The objective of this study is to observe pathogenic lesions of joint cartilages in rats fed with T-2 toxin under a selenium deficiency nutrition status in order to determine possible etiological factors causing Kashin-Beck disease (KBD). Sprague-Dawley rats were fed selenium-deficient or control diets for 4 weeks prior to their being exposed to T-2 toxin. Six dietary groups were formed and studied 4 weeks later, i.e., controls, selenium-deficient, low T-2 toxin, high T-2 toxin, selenium-deficient diet plus low T-2 toxin, and selenium-deficient diet plus high T-2 toxin. Selenium deficiencies were confirmed by the determination of glutathione peroxidase activity and selenium levels in serum. The morphology and pathology (chondronecrosis) of knee joint cartilage of experimental rats were observed using light microscopy and the expression of proteoglycans was determined by histochemical staining. Chondronecrosis in deep zone of articular cartilage of knee joints was seen in both the low and high T-2 toxin plus selenium-deficient diet groups, these chondronecrotic lesions being very similar to chondronecrosis observed in human KBD. However, the chondronecrosis observed in the rat epiphyseal growth plates of animals treated with T-2 toxin alone or T-2 toxin plus selenium-deficient diets were not similar to that found in human KBD. Our results indicate that the rat can be used as a suitable animal model for studying etiological factors contributing to the pathogenesis (chondronecrosis) observed in human KBD. However, those changes seen in epiphyseal growth plate differ from those seen in human KBD probably because of the absence of growth plate closure in the rat.

Oxidant damage in Kashin-Beck disease and a rat Kashin-Beck disease model by employing T-2 toxin treatment under selenium deficient conditions.

Kashin-Beck disease (KBD) is an endemic degenerative osteoarthropathy, but the mechanisms underlying its pathogenesis remains unclear. This study compares antioxidant capacity and lipid peroxidation using a novel model, in which rats were administered a selenium-deficient diet for 4 weeks prior to their exposure to T-2 toxin for 4 weeks. Changes in cell morphology and empty chondrocyte lacunae indicative of cell death, as well as cartilage proteoglycan loss in the deep zone of articular cartilage of knee joints were observed in rats with selenium-deficient diet plus T-2 toxin treatment. These changes were similar to those observed previously in KBD. The levels of thiobarbituric acid reactive substances (TBARS), indicative of lipid peroxidation in serum and cartilage, were significantly increased in all experimental groups compared to the normal diet group, while the levels of antioxidants, measured as total antioxidant capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidases (GPX), in serum and cartilage were significantly lower than that in the normal diet group. The mRNA expression of those antioxidants in cartilage tissue was significantly reduced by T-2 toxin alone or by selenium-deficient diet plus T-2 toxin treatment. These results indicate that increasing TBARS and decreasing antioxidants in serum and cartilage by T-2 toxin treatment with a selenium-deficient nutritional status may alter oxidative stress in joint tissues and contribute to the pathological process of cartilage damage in KBD.

Sodium valproate induces mitochondria-dependent apoptosis in human hepatoblastoma cells.

BACKGROUND: Sodium valproate inhibits proliferation in neuroblastoma and glioma cells, and inhibits proliferation and induces apoptosis in hepatoblastoma cells. Information describing the molecular pathways of the antitumor effects of sodium valproate is limited; therefore, we explored the mechanisms of action of sodium valproate in the human hepatoblastoma cell line, HepG2. METHODS: The effects of sodium valproate on the proliferation of HepG2 cells were evaluated by the Walsh-schema transform and colony formation assays. Sodium valproate-induced apoptosis in HepG2 cells was investigated with fluorescence microscopy to detect morphological changes; by flow cytometry to calculate DNA ploidy and apoptotic cell percentages; with Western blotting analyses to determine c-Jun N-terminal kinases (JNK), p-JNK, Bcl-2, Bax, and caspase-3 and -9 protein expression levels; and using JC-1 fluorescence microscopy to detect the membrane potential of mitochondria. Statistical analyses were performed using one-way analysis of variance by SPSS 13.0 software. RESULTS: Our results indicated that sodium valproate treatment inhibited the proliferation of HepG2 cells in a dose-dependent manner. Sodium valproate induced apoptosis in HepG2 cells as it: caused morphologic changes associated with apoptosis, including condensed and fragmented chromatin; increased the percentage of hypodiploid cells in a dose-dependent manner; increased the percentage of annexin V-positive/propidium iodide-negative cells from 9.52% to 74.87%; decreased JNK and increased phosphate-JNK protein expression levels; reduced the membrane potential of mitochondria; decreased the ratio of Bcl-2/Bax; and activated caspases-3 and -9. CONCLUSION: Sodium valproate inhibited the proliferation of HepG2 cells, triggered mitochondria-dependent HepG2 cell apoptosis and activated JNK.

Expressions of nucleoside diphosphate kinase (nm23) in tumor tissues are related with metastasis and length of survival of patients with hepatocellular carcinoma.

OBJECTIVE: To evaluate the relationship of expressions of nucleoside diphosphate kinase (nm23) and proliferating cell nuclear antigen (PCNA), as well as apoptosis, with the prognosis of HCC patients by analyzing their pathological and clinical data. METHODS: The expressions of nm23 and PCNA were analyzed by immunohistochemistry and the apoptotic phenomena were detected by TUNEL technique in the liver samples from 43 HCC tissues, 39 para-neoplastic tissues, and 10 normal tissues. The mean apoptosis index (AI) and proliferative index (PI) in individual sample were calculated. RESULTS: As shown by the detection, 32.6% of carcinomas had negative nm23 signal in tumor tissues, whereas all para-neoplastic and normal tissues had positive nm23. The AI in nm23 positive HCC was significantly higher than that in nm23 negative one, with statistical difference (P<0.05). Furthermore, the expressions of nm23, and the values of AI and PI were contrastively analyzed with some main pathological and clinical data of HCC. It revealed that HCC with extrahepatic metastasis showed remarkable correlation with the negative nm23 (P=0.013) and higher PI values of HCC (P=0.015). The disease-free survival in HCC patients with negative nm23 expression was significantly poorer than that in patients with positive nm23 expression. CONCLUSIONS: These data suggest that expressions of nm23 protein in tumor tissues are correlated with occurrences of metastasis and length of survival of the HCC patients, which may be an indicator for their prognosis.

Evaluation of liposomal curcumin cytochrome p450 metabolism.

BACKGROUND: Curcumin (diferuloylmethane) is a commonly used spice and nutritional supplement that has demonstrated potential anti-tumor and anti-inflammatory activity. There is limited information regarding curcumin metabolism and the potential for drug-drug interactions. The objective of this study was to characterize the hepatic metabolism of synthetic curcumin used in the liposomal curcumin formulation. MATERIALS AND METHODS: High-throughput cytochrome P450 (CYP450) metabolism inhibition assays were conducted in vitro evaluating CYP450 3A4, 2C8, 2C9, and 2D6. An ex vivo model of cryopreserved human hepatocytes was used to evaluate the CYP450 metabolism induction potential of curcumin for CYP P450 3A4, 2C8/2C9, and 2D6. RESULTS: In the in vitro CYP450 inhibition studies, curcumin at any concentration did not inhibit CYP450 3A4 or CYP450 2D6 activity. At a curcumin concentration of 58.3 microM, 10.5% and 22.5% inhibition of CYP450 2C9 and CYP450 2C8 activity, respectively, was observed. In the ex vivo hepatocyte inductions studies, minimal to no induction of CYP450 3A4, CYP450 2C8/2C9 or CYP450 2D6 was observed. Rifampicin did not induce the metabolism of curcumin and curcumin did not induce its own metabolism. CONCLUSION: There is low potential for CYP450 mediated drug interactions at physiologic serum concentrations of liposomal curcumin. Based on preliminary data, liposomal curcumin will not interact with other chemotherapy agents that are metabolized and/or eliminated via the primary drug metabolizing CYP450 pathways.

Effects of moniliformin and selenium on human articular cartilage metabolism and their potential relationships to the pathogenesis of Kashin-Beck disease.

OBJECTIVE: To investigate the effects of mycotoxin moniliformin (MON) on the metabolism of aggrecan and type II collagen in human chondrocytes in vitro and the relationship between MON and Kashin-Beck disease (KBD). METHODS: Human chondrocytes were isolated and cultured on bone matrix gelatin to form an artificial cartilage model in vitro with or without MON toxin. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The expression of aggrecan and type II collagen in the cartilage was determined using immunocytochemical staining. RESULTS: MON toxin inhibited chondrocyte viability in dose-dependent and time-dependent manners. MON reduced aggrecan and type II collagen syntheses in the tissue-engineered cartilage. MON also increased the expression of matrix metalloproteinase-1 (MMP-1), MMP-13, BC4 epitopes, and CD44 in cartilages. However, the expression of 3B3(-) epitopes in cartilages was inhibited by MON. Selenium partially alleviated the damage of aggrecan induced by MON toxin. CONCLUSION: MON toxin promoted the catabolism of aggrecan and type II collagen in human chondrocytes.