Dual-Targeted Lactoferrin Shell-Oily Core Nanocapsules for Synergistic Targeted/Herbal Therapy of Hepatocellular Carcinoma

Herein, both strategies of synergistic drug combination together with dual active tumor targeting were combined for effective therapy of hepatocellular carcinoma (HCC). Therefore, based on the tumor sensitizing action, the herbal quercetin (QRC) was co-delivered with the targeted therapeutic drug sorafenib (SFB), preformulated as phospholipid complex, via protein shell-oily core nanocapsules (NCs). Inspired by the targeting action of lactoferrin (LF) via binding to LF receptors overexpressed by HCC cells, LF shell was electrostatically deposited onto the drug-loaded oily core to elaborate LF shell-oily core NCs. For dual tumor targeting, lactobionic acid (LA) or glycyrrhetinic acid (GA) was individually coupled to LF shell for binding to asialoglycoprotein and GA receptors on liver cancer cells, respectively. Compared to LF and GA/LF NCs, the dual-targeted LA/LF-NCs showed higher internalization into HepG2 cells with 2-fold reduction in half-maximal inhibitory concentration compared to free combination therapy after 48 h. Moreover, dual-targeted LF-NCs showed powerful in vivo antitumor efficacy. It was revealed as significant downregulation of the mRNA expression levels of nuclear factor-kappa B and tumor necrosis factor α as well as suppression of Ki-67 protein expression level in diethylnitrosamine (DEN)-induced HCC mice (P < 0.05). Furthermore, dual-targeted LF-NCs attenuated the liver toxicity induced by DEN in animal models. Overall, this study proposes dual-targeted LF-NCs for combined delivery of SFB and QRC as a potential therapeutic HCC strategy.

Formation and inhibition of N-nitrosodiethanolamine in cosmetics under pH, temperature, and fluorescent, ultraviolet, and visual light

N-nitrosodiethanolamine (NDELA), a type of nitrosamine, is a possible human carcinogen that may form in cosmetic products. The aim of this study was to examine the formation and inhibition of NDELA through chemical reactions of secondary amines including mono-ethanolamine, di-ethanolamine (DEA), and tri-ethanolamine (TEA), and sodium nitrite (SN) under varying conditions such as pH, temperature, and fluorescent, ultraviolet (UV), and visual light (VIS) using liquid chromatography-mass spectroscopy. In a mixture of TEA and SN under acidic conditions pH 2, residual NDELA concentrations rose significantly under various storage conditions in the following order: 50°C > 40°C > UV (2 W/m²) > VIS (4000 lux) > fluorescent light > 25°C > 10°C. In a mixture of DEA and SN under the same acidic pH 2 conditions, NDELA formation was significantly elevated in the following order: UV (2 W/m²) > VIS (4000 lux) > 50°C > 40°C > fluorescent light > 25°C > 10°C. Inhibition of NDELA formation by d-mannitol, vitamin C (Vit C), or vitamin E (Vit E) was determined under varying conditions of pH, temperature, and fluorescent, UV, and VIS. At high concentrations of 100 or 1000 µg/ml, Vit E significantly decreased residual NDELA compared with control levels under acidic pH 2, but not under basic pH 6. Among various antioxidants, Vit E reacted more effectively with many nitrosating agents such as nitrate and nitrite found in cosmetic products. Therefore, to reduce NDELA, it is recommended that cosmetics be stored under cool/amber conditions and that Vit E or Vit C inhibitors of nitrosation be optimally added to cosmetic formulations at concentrations between 100 and 1000 µg/ml.

Voluntary Wheel Running Reduces the Acute Inflammatory Response to Liver Carcinogen in a Sex-specific Manner

Inflammation contributes to the development of cancer, yet acute inflammatory responses are also needed to eradicate tumorigenic cells and activate adaptive immune responses to combat cancer. Physical exercise has direct immunomodulatory effects, and in line with this, exercise has been demonstrated to inhibit tumor growth, including diethylnitrosamine-(DEN)-induced hepatocarcinoma. Having observed a sex-dependent development of DEN-induced hepatocarcinoma, we aimed to evaluate the effect of exercise and sex on the acute inflammatory response to DEN. Thus, we randomized male and female mice to cages with or without running wheels for 6 weeks, whereafter DEN was administered and the inflammatory response was evaluated for up to 96 hours. DEN administration caused marked acute inflammatory responses in female mice with weight loss, reduced food intake, release of liver enzymes, and increased systemic levels of IL6. Moreover, DEN caused increased hepatic expression of cytokines, immune cell markers, and components of the toll-like receptor signaling pathway. In male mice, DEN administration provoked similar physiologic effects with weight loss and reduced food intake, but less systemic and hepatic acute inflammation, which was associated with a higher baseline expression of the detoxifying enzyme glutathione S-transferase and lower expression of ERα in male mice. Voluntary wheel running attenuated systemic and hepatic inflammation, in particular in the female mice, and shifted the peak time of the inflammatory response. In conclusion, DEN elicited an acute inflammatory response in particular in female mice, and this response was attenuated by prior exercise. Cancer Prev Res; 10(12); 719-28. ©2017 AACR.

Evidence for a Role of the Transcriptional Regulator Maid in Tumorigenesis and Aging

Maid is a helix-loop-helix protein that is involved in cell proliferation. In order to further elucidate its physiological functions, we studied Maid activity in two small fish model systems. We found that Maid expression was greatest in zebrafish liver and that it increased following partial hepatectomy. Maid levels were also high in hepatic preneoplastic foci induced by treatment of zebrafish with diethylnitrosamine (DEN), but low in hepatocellular carcinomas (HCC), mixed tumors, and cholangiocarcinomas developing in these animals. In DEN-treated transgenic medaka overexpressing Maid, hepatic BrdU uptake and proliferation were reduced. After successive breedings, Maid transgenic medaka exhibited decreased movement and a higher incidence of abnormal spine curvature, possibly due to the senescence of spinal cord cells. Taken together, our results suggest that Maid levels can influence the progression of liver cancer. In conclusion, we found that Maid is important regulator of hepatocarconogenesis and aging.

Assessing granular media filtration for the removal of chemical contaminants from wastewater

Granular media filtration was evaluated for the removal of a suite of chemical contaminants that can be found in wastewater. Laboratory- and pilot-scale sand and granular activated carbon (GAC) filters were trialled for their ability to remove atrazine, estrone (E1), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR) and N-nitrosodiethylamine (NDEA). In general, sand filtration was ineffective in removing the contaminants from a tertiary treated wastewater, with the exception of E1 and EE2, where efficient removals were observed after approximately 150 d. Batch degradation experiments confirmed that the removal of E1 was through biological activity, with a pseudo-first-order degradation rate constant of 7.4 × 10(-3) h(-1). GAC filtration was initially able to effectively remove all contaminants; although removals decreased over time due to competition with other organics present in the water. The only exception was atrazine where removal remained consistently high throughout the experiment. Previously unreported differences were observed in the adsorption of the three nitrosamines, with the ease of removal following the trend, NDEA > NMOR > NDMA, consistent with their hydrophobic character. In most instances the removals from the pilot-scale filters were generally in agreement with the laboratory-scale filter, suggesting that there is potential in using laboratory-scale filters as monitoring tools to evaluate the performance of pilot- and possibly full-scale sand and GAC filters at wastewater treatment plants.

Comparison of N-nitrosodiethylamine degradation in water by UV irradiation and UV/O3: efficiency, product and mechanism

N-nitrosodiethylamine (NDEA) is a member of nitrosamines, which is strong carcinogenic. In order to explore an effective treatment method for NDEA removal from water, sole UV irradiation and UV/O(3) were carried out in this study. The removal efficiency, degradation products and pathways were compared between those two processes. Results showed that NDEA removal efficiency achieved 99% within 15 min by both UV and UV/O(3). Degradation reaction well followed pseudo-first-order kinetics. Water pH had different effect on NDEA degradation in those two processes. Acidic and neutral conditions were good for NDEA degradation by sole UV irradiation. However, NDEA underwent rapid degradation under various pH conditions in the UV/O(3) process. Though the ozone introduction in the UV/O(3) process had little effect on NDEA degradation efficiency, it had significant effect on its degradation products and pathways. Methylamine, dimethylamine, ethylamine and diethylamine were observed as aliphatic amine products of NDEA degradation in both two processes. They were assumed to arise due to N-N bond fission under UV irradiation, or due to the reaction of NDEA and hydroxyl radicals in the UV/O(3) process.

Interaction of N-nitrosodiethylamine/bovine serum albumin complexes with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine monolayers at the air-water interface

We report the effect of N-nitrosodiethylamine (NDA) on the interaction between bovine serum albumin (BSA) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine monolayers (DPPC) at the air-water interface. We prepared aqueous solutions of NDA/BSA complexes maintaining a constant concentration of BSA of 1.49 x 10(-9) M and using NDA concentrations to obtain 2000, 4000, 6000, 12,500, and 25,000 NDA/BSA molar ratios. The hysteresis area and the compressional modulus of the compression-expansion cycles performed at different times were dependent on the NDA concentration. The cycles performed demonstrate the stability of the new phase of DPPC/BSA and DPPC/NDA/BSA monolayers. This was achieved probably because the BSA concentration used was lower than the one needed for BSA to inhibit the return of DPPC molecules to the interface. Results of the compressional modulus at the onset of the new phase, obtained around 17 mN/m, 15 min and 1, 3, 5, and 12 h after DPPC deposition, indicated that the 3.0 x 10(-6) M NDA concentration produced a more rigid film, probably due to the higher alpha-helix content of BSA. AFM images were obtained for DPPC/BSA and two DPPC/NDA/BSA complexes. Our images show that 12,500 NDA/BSA molecules were mostly adsorbed in the liquid condensed phase. However, BSA molecules were distributed more homogeneously.

Different mutation patterns of mitochondrial DNA displacement-loop in hepatocellular carcinomas induced by N-nitrosodiethylamine and a choline-deficient l-amino acid-defined diet in rats

Mutations of the mitochondria DNA (mtDNA) displacement loop (D-loop) were investigated to clarify different changes of exogenous and endogenous liver carcinogenesis in rats. We induced hepatocellular carcinomas (HCCs) in rats with N-nitrosodiethylamine (DEN) and a choline-deficient l-amino acid-defined (CDAA) diet. DNAs were extracted from 10 HCCs induced by DEN and 10 HCCs induced by the CDAA diet. To identify mutations in mtDNA D-loop, polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis, followed by nucleotide sequencing, was performed. Mutations were detected in 5 out of 10 HCCs (50%) induced by DEN. Four out of 5 mutations were G/C to A/T transitions at positions 15707, 15717, 15930, and 16087, and one T/A to C/G transition at position 15559. By contrast, no mutations were found in 10 HCCs induced by the CDAA diet. These results demonstrated that mutations in mtDNA D-loop occur in rat HCCs induced by DEN but not by the CDAA diet, suggesting that mtDNA D-loop is a target of exogenous liver carcinogenesis in rats.

Interfacial Behavior of N-Nitrosodiethylamine/Bovine Serum Albumin Complexes at the Air−Water and the Chloroform−Water Interfaces by Axisymmetric Drop Tensiometry

Interfacial properties of N-nitrosodiethylamine/bovine serum albumin (NDA/BSA) complexes were investigated at the air-water interface. The interfacial behavior at the chloroform-water interface of the interaction product of phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), dissolved in the chloroform phase, and NDA/BSA complex, in the aqueous phase, were also analyzed by using a drop tensiometer. The secondary structure changes of BSA with different NDA concentrations were monitored by circular dichroism spectroscopy at different pH and the NDA/BSA interaction was probed by fluorescence spectroscopy. Different NDA/BSA mixtures were prepared from 0, 7.5 x 10(-5), 2.2 x 10(-4), 3.7 x 10(-4), 5 x 10(-4), 1.6 x 10(-3), and 3.1 x 10(-3) M NDA solutions in order to afford 0, 300/1, 900/1, 1 500/1, 2 000/1, 6 000/1, and 12 500/1 NDA/BSA molar ratios, respectively, in the aqueous solutions. Increments of BSA alpha-helix contents were obtained up to the 2 000/1 NDA/BSA molar ratio, but at ratios beyond this value, the alpha-helix content practically disappeared. These BSA structure changes produced an increment of the surface pressure at the air-water interface, as the alpha-helix content increased with the concentration of NDA. On the contrary, when alpha-helix content decreased, the surface pressure also appeared lower than the one obtained with pure BSA solutions. The interaction of DPPC with NDA/BSA molecules at the chloroform-water interface produced also a small, but measurable, pressure increment with the addition of NDA molecules. Dynamic light scattering measurements of the molecular sizes of NDA/BSA complex at pH 4.6, 7.1, and 8.4 indicated that the size of extended BSA molecules at pH 4.6 increased in a greater proportion with the increment in NDA concentration than at the other studied pH values. Diffusion coefficients calculated from dynamic surface tension values, using a short-term solution of the general adsorption model of Ward and Tordai, also showed differences with pH and the NDA concentration. Both, the storage and loss dilatational elastic modulus were obtained at the air-water and at the chloroform-water interfaces. The interaction of NDA/BSA with DPPC at the chloroform-water produced a less rigid monolayer than the one obtained with pure DPPC (1 x 10(-5) M), indicating a significant penetration of NDA/BSA molecules at the interface. At short times and pH 4.6, the values of the storage elastic modulus were larger and more sensible to the NDA addition than the ones at pH 7.1 and 8.4, probably due to a gel-like network formation at the air-water interface.

Suppression of N-nitrosodiethylamine induced hepatocarcinogenesis by silymarin in rats

Antioxidants are one of the key players in tumorigenesis, several natural and synthetic antioxidants were shown to have anticancer effects. In the present investigation the efficacy of silymarin on the antioxidant status of N-nitrosodiethylamine (NDEA) induced hepatocarcinogenesis in Wistar albino male rats were assessed. The animals were divided into five groups. The animals in the groups 1 and 3 were normal control and silymarin control, respectively. Groups 2, 4 and 5 were administered with 0.01% NDEA in drinking water for 15 weeks to induce hepatocellular carcinoma (HCC). Starting 1 week prior to NDEA administration group 4 animals were treated with silymarin in diet for 16 weeks, 10 weeks after NDEA administration group 5 animals were treated with silymarin and continued till the end of the experiment period (16 weeks). After the experimental period the body weight, relative liver weight, number of nodules, size of nodules, the levels of lipid peroxidation, glutathione (GSH), and the activities of antioxidant enzymes were assessed in both haemolysate and liver tissue. In group 2 hepatocellular carcinoma induced animals there was an increase in the number of nodules, relative liver weight. The levels of lipid peroxides were elevated with subsequent decrease in the body weight, (glutathione) GSH, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD). In contrast, silymarin + NDEA treated groups 4 and 5 animals showed a significant decrease in the number of nodules with concomitant decrease in the lipid peroxidation status. The levels of GSH and the activities of antioxidant enzymes in both haemolysate and liver were improved when compared with hepatocellular carcinoma induced group 2 animals. The electron microscopy studies were also carried out which supports the chemopreventive action of the silymarin against NDEA administration during liver cancer progression. These findings suggest that silymarin suppresses NDEA induced hepatocarcinogenesis by modulating the antioxidant defense status of the animals.

Mass spectrometric methodology for the determination of glyoxaldeoxyguanosine and O6-hydroxyethyldeoxyguanosine DNA adducts produced by nitrosamine bident carcinogens

N-Nitrosodiethanolamine (NDELA) is a bident carcinogen that undergoes both P-450 mediated alpha-hydroxylation and beta-oxidation, leading ultimately to the formation of two prominent DNA adducts, glyoxaldeoxyguanosine (gdG) and O6-2-hydroxyethyldeoxyguanosine (OHEdG), in rat liver. HPLC coupled with electrospray ionization (ESI) and tandem mass spectrometry was used for both detection and quantification of gdG and OHEdG. The method, which is fast, sensitive, and unambiguous, is a significant improvement over the previous 32P-postlabeling methodology. A rapid procedure for the enzymatic hydrolysis of the DNA under acidic conditions preserved the integrity of the pH sensitive gdG adducts. Glyoxal and 3-nitroso-2-oxazolidinone generated gdG and OHEdG adducts, respectively, in calf thymus DNA (ct-DNA) in a concentration (range of 10(4)) dependent manner permitting optimization. Isotopomeric internal standards were prepared from the modified guanine derivatives by enzymatic trans-glycosylation. Quantitative HPLC-ESI-MS/MS analysis employing selective reaction monitoring (SRM) for the loss of the deoxyribose fragment was utilized. Both adducts could be detected in the liver DNA of rats that were administered NDELA in a dose range of 0.4-0.8 mmol/kg. At the highest dose, gdG adducts (4.4-11 adducts/10(6) nuc.) were more abundant than OHEdG adducts (0.35-0.87 adducts/10(6) nuc.). Conversely, OHEdG adducts were produced in higher yields in ct-DNA than were gdG adducts at the same reagent concentrations.

Further development of 32P-postlabeling for the detection of alkylphosphotriesters: evidence for the long-term nonrandom persistence of ethyl-phosphotriester adducts in vivo

DNA phosphate oxygens are sites for alkylation leading to phosphotriester adducts (PTEs). PTEs are reported to be both abundant and persistent and so may serve as long-term markers of genotoxicity. Previously, we reported a 32P-postlabeling assay for the specific detection of PTEs plus identification of nucleosides located 5' to PTEs. Using this, we demonstrated the nonrandom nature of ethyl-PTEs (Et-PTEs) in vivo, these results being suggestive of either the nonrandom formation of Et-PTEs in vivo or sequence specific Et-PTE repair. Presently, we report the further development and validation of the 32P-postlabeling assay, to permit the more straightforward determination of nucleosides 5' to PTEs and, using this, have investigated the long-term persistence of PTEs in vivo. Analysis of liver DNA of mice treated in vivo with N-nitrosodiethylamine reveals an initial decline in the level of Et-PTEs (t1/2<24 h) as well as their nonrandom persistence for the duration of the time course, with approximately 37 and approximately 15% of the initial Et-PTEs remaining 4 and 56 days after treatment, respectively. From this, we conclude that Et-PTEs are suitable as long-term markers of genotoxic exposure and that putative PTE repair is not responsible for their nonrandom manifestation. However, the possibility of active repair contributing to the initial decline of Et-PTEs is considered.

DNA adducts from N-nitrosodiethanolamine and related beta-oxidized nitrosamines in vivo: (32)P-postlabeling methods for glyoxal- and O(6)-hydroxyethyldeoxyguanosine adducts

The mechanism by which environmentally prevalent N-nitrosodiethanolamine (NDELA) and related 2-hydroxyethyl- or other beta-oxidized nitrosamines initiate the carcinogenic process has remained obscure. (32)P-Postlabeling assays for the pH sensitive glyoxal-deoxyguanosine (gdG) and the O(6)-2-hydroxyethyldeoxyguanosine (OHEdG) DNA adducts have been developed as probes in this mechanistic investigation and used in both in vitro and in vivo experiments. The ready cleavage of the glyoxal fragment from gdG at pH 7 and greater has required methods of optimization in order to achieve a detection limit of 0.05 micromol/mol of DNA. Nuclease P1 treatment enhances the detection of gdG adducts but does not increase the detection limit for OHEdG. For OHEdG, best results were achieved using fraction collection from HPLC (0.3 micromol/mol of DNA). Using radiochemical methods, both adducts could be detected either by HPLC or 2D TLC. NDELA, N-nitrosomorpholine (NMOR), N-nitrosomethyethanolamine (NMELA), and N-nitrosoethylethanolamine (NEELA) all produce both gdG and OHEdG adducts in rat liver DNA in vivo and are called bident carcinogens because fragments from both chains of the nitrosamine are incorporated into DNA. N-Nitroso-2-hydroxymorpholine (NHMOR), a metabolite of NDELA and NMOR, generates gdG in DNA in vitro and in vivo. gdG DNA adducts were found in the range 1.1-6.5 micromol/mol of DNA. OHEdG DNA adducts were produced from equimolar amounts of nitrosamines in rat liver in vivo over the range 4-25 micromol/mol of DNA and in the order NMELA > NEELA > NDELA > NMOR. Deuterated isotopomers of NDELA showed a marked isotope effect on DNA OHEdG adduct formation. alpha-Deuteration markedly decreased OHEdG adduct formation while beta-deuteration had the opposite effect. These data support the hypothesis that NDELA and related nitrosamines are activated by both enzyme mediated alpha-hydroxylation and beta-oxidation. The formation of OHEdG adducts from NDELA requires alpha-hydroxylation of the 2-hydroxyethyl chain, and formation of gdG necessitates a beta-oxidation as well. The bident nature of these carcinogens may explain why they are relatively potent carcinogens despite the fact that major proportions of doses are excreted unchanged.

Mutation and formation of methyl- and hydroxylguanine adducts in DNA caused by N-nitrosodimethylamine and N-nitrosodiethylamine with UVA irradiation

Previously we reported that when Escherichia coli was treated with N-nitrosodialkylamine under irradiation with near UV light, mutagenesis of the bacteria took place: there was no requirement for metabolic activation. We have now studied the spectra of mutations caused by N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) with UVA (320-400 nm) irradiation, using standard tester strains for identifying types of mutations. Induced mutations by NDMA + UVA were the transition GC-->AT and transversions GC-->CG, GC-->TA and AT-->TA. NDEA + UVA induced mainly the GC-->CG transversion. In both cases no frameshift mutations were observed. When O6-alkylguanine-DNA alkyltransferase-deficient strains of E. coli and Salmonella typhimurium were used, the mutation levels with both NDMA + UVA and NDEA + UVA became remarkably higher than those observed with the proficient strains. We measured the O6-methylguanine (O6-meG) level in calf thymus DNA treated with NDMA + UVA. The O6-meG level was increased as a function of NDMA concentration and irradiation time. We also detected N7-methylguanine in DNA treated with NDMA + UVA. In our previous work we found formation of 8-oxodeoxyguanosine (8-oxodG) in DNA treated with N-nitrosomorpholine + UVA. The 8-oxodG/dG ratio in DNA treated with NDMA + UVA increased up to 42-fold over that of the untreated control and that in DNA treated with NDEA + UVA increased up to 67-fold. 8-OxodG formation was not affected by replacing H2O in the reaction mixture with D2O, suggesting that singlet oxygen is not the rate limiting factor in this photoactivation. We conclude that both alkylation and oxidation are involved in mutations induced by NDMA + UVA and NDEA + UVA.