Chemical basis of inflammation-induced carcinogenesis

A case-control study on the association between bladder cancer and prior bladder calculus

Background

Bladder calculus is associated with chronic irritation and inflammation. As there is substantial documentation that inflammation can play a direct role in carcinogenesis, to date the relationship between stone formation and bladder cancer (BC) remains unclear. This study aimed to examine the association between BC and prior bladder calculus using a population-based dataset.

Methods

This case–control study included 2,086 cases who had received their first-time diagnosis of BC between 2001 and 2009 and 10,430 randomly selected controls without BC. Conditional logistic regressions were employed to explore the association between BC and having been previously diagnosed with bladder calculus.

Results

Of the sampled subjects, bladder calculus was found in 71 (3.4%) cases and 105 (1.1%) controls. Conditional logistic regression analysis revealed that the odds ratio (OR) of having been diagnosed with bladder calculus before the index date for cases was 3.42 (95% CI = 2.48-4.72) when compared with controls after adjusting for monthly income, geographic region, hypertension, diabetes, coronary heart disease, and renal disease, tobacco use disorder, obesity, alcohol abuse, and schistosomiasis, bladder outlet obstruction, and urinary tract infection. We further analyzed according to sex and found that among males, the OR of having been previously diagnosed with bladder calculus for cases was 3.45 (95% CI = 2.39-4.99) that of controls. Among females, the OR was 3.05 (95% CI = 1.53-6.08) that of controls.

Conclusions

These results add to the evidence surrounding the conflicting reports regarding the association between BC and prior bladder calculus and highlight a potential target population for bladder cancer screening.

Lipopolysaccharide challenge of the mammary gland in cows induces nitrosative stress that impairs milk oxidative stability

The aim of this work was to study the effects of mastitis induced by intramammary lipopolysaccharide (LPS) challenge on milk oxidative stability, as well as to understand the underlying biochemical processes that cause such changes. LPS challenge was associated with nitric oxide burst from the surrounding mammary epithelial cells and consequently induced nitrosative stress that was induced by the formation of NO2• from nitrite by lactoperoxidase. This response was associated with an ∼3-fold increased formation of hazardous compounds: nitrotyrosines, carbonyls and lipid peroxides. We sustained the involvement of xanthine oxidase as a major source of hydrogen peroxide. In consistent with previous findings, catalase has been shown to play a major role in modulating the nitrosative stress by oxidizing nitrite to nitrate. The current hygienic quality criteria cannot detect mixing of low-quality milk, such as milk with high somatic cells, and nitrite with high-quality milk. Thus, development of an improved quality control methodology may be important for the production of high-quality milk.

The characteristics of the expression of heat shock proteins and COX-2 in the liver of hamsters infected with Clonorchis sinensis, and the change of endocrine hormones and cytokines

The liver fluke Clonorchis sinensis (Digenea) is a high-risk parasite that causes serious diseases such as cirrhosis, carcinogenic liver damage and clonorchiasis in East Asia. This study was conducted to evaluate the relationship between stress/endocrine hormones and inflammation induced by infection as well as the expression of heat shock proteins (hsp-27, hsp-90), cox-2 and cytokines in the livers of hamsters infected with C. sinensis. The average body weight of infected hamsters decreased up to 25% compared with that of the control group, and bile duct hyperplasia with inflammation, liver fibrosis and hepatic necrosis were observed in C. sinensis-infected livers. The expression of hsp-27, hsp-90, and cox-2 was significantly increased in the livers of C. sinensis-infected hamsters compared with the control group. Moreover, the expression levels of inflammatory cytokines (IL-1beta, IL-2, TGF-beta2 and IFN-alpha1) were markedly increased in the livers of the infected group compared with those of the control group. Consistently, plasma IL-3 and IL-6 levels gradually increased during the infection period, and the concentration levels of testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), corticosterone, and adrenocorticotropic hormone (ACTH) in C. sinensis-infected hamsters increased over 25%, compared with those of the uninfected normal group. These results demonstrate that C. sinensis infection may increase the expression of hsp27, hsp90 and cox-2 as well as it may cause periductal fibrosis, chronic inflammation and hepatic necrosis in the liver. Furthermore, the results indicate that C. sinensis infection induces not only stress-induced hormone imbalance but also the sustained secretion of inflammatory cytokines through chronic stress/stimuli.

Comparative analysis of four oxidized guanine lesions from reactions of DNA with peroxynitrite, singlet oxygen, and γ-radiation

Oxidative damage to DNA has many origins, including irradiation, inflammation, and oxidative stress, but the chemistries are not the same. The most oxidizable base in DNA is 2-deoxyguanosine (dG), and the primary oxidation products are 8-oxodG and 2-amino-imidazolone. The latter rapidly converts to 2,2-diamino-oxazolone (Ox), and 8-oxodG is further oxidized to spiroiminodihydantoin (Sp) and guanidinohydantoin (Gh). In this study, we have examined the dose–response relationship for the formation of the above four products arising in calf thymus DNA exposed to gamma irradiation, photoactivated rose bengal, and two sources of peroxynitrite. In order to carry out these experiments, we developed a chromatographic system and synthesized isotopomeric internal standards to enable accurate and precise analysis based upon selected reaction monitoring mass spectrometry. 8-OxodG was the most abundant products in all cases, but its accumulation was highly dependent on the nature of the oxidizing agent and the subsequent conversion to Sp and Gh. Among the other oxidation products, Ox was the most abundant, and Sp was formed in significantly greater yield than Gh.

The metabolic syndrome and risk factors for biliary tract cancer: a case-control study in China

OBJECTIVES

Recent data show that the metabolic syndrome may play a role in several cancers, but the etiology for biliary tract cancer is incompletely defined. The present aim was to evaluate risk factors for biliary tract cancer in China.

METHODS

A case-control study in which cases were biliary tract cancer patients referred to Peking Union Medical College Hospital (PUMCH). Controls were randomly selected from an existing database of healthy individuals at the Health Screening Center of PUMCH. Data on the metabolic syndrome, liver diseases, family history, and history of diabetes and hypertension were collected by retrospective review of the patients' records and health examination reports or by interview.

RESULTS

A total of 281 patients (102 intrahepatic cholangiocarcinoma (ICC), 86 extrahepatic cholangiocarcinoma (ECC) and 93 gallbladder carcinoma (GC)) and 835 age- and sex-matched controls were enrolled. HBsAg+/anti-HBc+ (P=0.002), history of diabetes (P=0.000), cholelithiasis (P=0.000), TC (P=0.003), and HDL (P=0.000) were significantly related to ICC. Cholelithiasis (P=0.000), Tri (P=0.001), LDL (P=0.000), diabetes (P=0.000), Apo A (P=0.000) and Apo B (P=0.012) were significantly associated with ECC. Diabetes (P=0.017), cholelithiasis (P=0.000) and Apo A (P=0.000) were strongly inversely correlated with GC.

CONCLUSION

Cholelithiasis, HBV infection and metabolic symptoms may be potential risk factors for the development of biliary tract cancer.

Therapeutic effect of coenzyme Q10 against experimentally-induced hepatocellular carcinoma in rats

The therapeutic potential of coenzyme Q10 was investigated in rats with hepatocellular carcinoma induced by trichloroacetic acid (0.5g/kg/day, p.o., for five days). Coenzyme Q10 treatment (0.4mg/kg/day, i.p.) was applied for four weeks following trichloroacetic acid administration. Coenzyme Q10 significantly suppressed lipid peroxidation, prevented the depletion of reduced glutathione and superoxide dismutase activity, and decreased the elevations of tumor necrosis factor-α and nitric oxide in liver tissue of rats with hepatocellular carcinoma. Also, the histopathological dysplastic changes induced by trichloroacetic acid in liver tissue were ameliorated by coenzyme Q10. Immunohistochemical analysis revealed that coenzyme Q10 significantly decreased the expression of hepPar-1, alpha-fetoprotein, inducible nitric oxide synthase, cyclooxygenase-2 and nuclear factor-κB in liver tissue of rats with hepatocellular carcinoma. It was concluded that coenzyme Q10 may represent a potential therapeutic option for liver carcinogenesis.

Paradoxical roles of tumour necrosis factor-alpha in prostate cancer biology

Tumour necrosis factor (TNF) is a pleiotropic cytokine with dual roles in cancer biology including prostate cancer (PCa). On the one hand, there is evidence that it stimulates tumour angiogenesis, is involved in the initiation of PCa from an androgen-dependent to a castrate resistant state, plays a role in epithelial to mesenchymal plasticity, and may contribute to the aberrant regulation of eicosanoid pathways. On the other hand, TNF has also been reported to inhibit neovascularisation, induce apoptosis of PCa cells, and stimulate antitumour immunity. Much of the confusion surrounding its seemingly paradoxical roles in cancer biology stems from the dependence of its effects on the biological model within which TNF is investigated. This paper will address some of these issues and also discuss the therapeutic implications.

Inflammatory events during murine squamous cell carcinoma development

Background

Squamous cell carcinoma (SCC) is one of the most common human cancers worldwide. In SCC, tumour development is accompanied by an immune response that leads to massive tumour infiltration by inflammatory cells, and consequently, local and systemic production of cytokines, chemokines and other mediators. Studies in both humans and animal models indicate that imbalances in these inflammatory mediators are associated with cancer development.

Methods

We used a multistage model of SCC to examine the involvement of elastase (ELA), myeloperoxidase (MPO), nitric oxide (NO), cytokines (IL-6, IL-10, IL-13, IL-17, TGF-β and TNF-α), and neutrophils and macrophages in tumour development. ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment.

Results

ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment. Significantly higher levels of IL-6 and lower levels of IL-10 were detected at 4 weeks following 7,12-Dimethylbenz(a)anthracene (DMBA) treatment. Similar levels of IL-13 were detected in the precancerous microenvironment compared with control tissue. We identified significant increases in the number of GR-1⁺ neutrophils and F4/80⁺/GR-1^- infiltrating cells in tissues at 4 and 8 weeks following treatment and a higher percentage of tumour-associated macrophages (TAM) expressing both GR-1 and F4/80, an activated phenotype, at 16 weeks. We found a significant correlation between levels of IL-10, IL-17, ELA, and activated TAMs and the lesions. Additionally, neutrophil infiltrate was positively correlated with MPO and NO levels in the lesions.

Conclusion

Our results indicate an imbalance of inflammatory mediators in precancerous SCC caused by neutrophils and macrophages and culminating in pro-tumour local tissue alterations.

Interleukin-11, an interleukin-6-like cytokine, is a promising predictor for bladder cancer prognosis

Numerous studies have suggested that interleukin 11 (IL-11) has roles in human gastric, prostate and bone cancer and endometrial carcinoma. Hence, we evaluated the expression of IL-11 in bladder cancer and the correlation of IL-11 levels and clinico-pathological features. The expression of IL-11 in primary human bladder cell culture, human bladder cancer cell lines, transitional cell carcinoma (TCC) and non-cancerous bladder tissues (NATs) were analyzed by western blotting. Enzyme-linked immunosorbent assay (ELISA) for urinary IL-11 was performed to compare the IL-11 levels in healthy subjects and subjects diagnosed with bladder cancer. Our study suggested that the expression of IL-11 in human bladder cancer cell lines and TCC was downregulated compared with primary human bladder cell culture and matched NATs. We also demonstrated reduced urinary levels of IL-11 in subjects with bladder cancer compared with healthy subjects. Furthermore, we revealed that the levels of IL-11 were associated with tumor grade and stage. The results suggested that reduced levels of IL-11 may play an important role in the carcinogenesis and progression of TCC. They also indicated that IL-11 may be a promising predictor for prognosis of TCC.

Preventing protein oxidation with sugars: scavenging of hypohalous acids by 5-selenopyranose and 4-selenofuranose derivatives

Heme peroxidases including myeloperoxidase (MPO) are released at sites of inflammation by activated leukocytes. MPO generates hypohalous acids (HOX, X = Cl, Br, SCN) from H(2)O(2); these oxidants are bactericidal and are key components of the inflammatory response. However, excessive, misplaced or mistimed production can result in host tissue damage, with this implicated in multiple inflammatory diseases. We report here methods for the conversion of simple monosaccharide sugars into selenium- and sulfur-containing species that may act as potent water-soluble scavengers of HOX. Competition kinetic studies show that the seleno species react with HOCl with rate constants in the range 0.8-1.0 × 10(8) M(-1) s(-1), only marginally slower than those for the most susceptible biological targets including the endogenous antioxidant, glutathione. The rate constants for the corresponding sulfur-sugars are considerably slower (1.4-1.9 × 10(6) M(-1) s(-1)). Rate constants for reaction of the seleno-sugars with HOBr are ~8 times lower than those for HOCl (1.0-1.5 × 10(7) M(-1) s(-1)). These values show little variation with differing sugar structures. Reaction with HOSCN is slower (~10(2) M(-1) s(-1)). The seleno-sugars decreased the extent of HOCl-mediated oxidation of Met, His, Trp, Lys, and Tyr residues, and 3-chlorotyrosine formation, on both isolated bovine serum albumin and human plasma proteins, at concentrations as low as 50 μM. These studies demonstrate that novel selenium (and to a lesser extent, sulfur) derivatives of monosaccharides could be potent modulators of peroxidase-mediated damage at sites of acute and chronic inflammation, and in multiple human pathologies.

Sulfonilamidothiopyrimidone and thiopyrimidone derivatives as selective COX-2 inhibitors: synthesis, biological evaluation, and docking studies

Newly synthesized sulfonilamidothiopyrimidone derivatives and a subset of 14 sulfonilamidothiopyrimidones and thiopyrimidones selected by an MTT assays cell viability guided selection from an in house collection were evaluated to determine the inhibitory effect on the PGE(2) formation in human peripheral blood lymphocytes (PBLs) using commercial ELISA. The newly synthesized sulfonilamidothiopyrimidone derivatives showed interesting pharmacological activities. Preliminary in vitro assays showed that compounds 2-5 are endowed with very high activity. Compound 2 was the most active as hCOX-2 inhibitor. The observed effects were not due to an inhibition of cell proliferation as proved by the BrdU assay. Western blot of COX-2 confirmed the inhibition on the PGE(2) secretion. Further evidence on the inhibitory potential and selectivity as COX-2 inhibitors of the selected compounds came from the in vitro screening. In order to better rationalize the action and the binding mode of these compounds, docking studies were carried out. These studies were in agreement with the biological data. Compounds 2-5 were able to fit into the active site of COX-2 with highest scores and interaction energies. Furthermore, compound 2, which showed an inhibition of around 50% on PGE(2) production, was the best scored in all the docking calculations carried out.

Oxidative stress in ulcerative colitis: an old concept but a new concern

Ulcerative colitis is an idiopathic, chronic and relapsing inflammatory bowel disease, which elicits the risk of colorectal cancer, the third most common malignancy in humans. It has been known for a long time that oxidative stress is a major pathogenic factor in the inflamed tissue that can pave the way towards DNA damage and carcinogenesis. However, the DNA damage produced due to oxidative stress in the inflamed tissue is not limited to the local site but extends globally, thereby augmenting the risk of global carcinogenesis. Targeting oxidative stress may provide an exciting avenue to combat inflammation-associated local as well as global DNA damage and the subsequent carcinogenesis. The present review portrays the role of oxidative stress in the pathogenesis of ulcerative colitis and the associated local as well as global DNA damage, which may lead to carcinogenesis.

Melatonin prevents hypochlorous acid-induced alterations in microtubule and chromosomal structure in metaphase-II mouse oocytes

Hypochlorous acid (HOCl) is generated by myeloperoxidase, using chloride and hydrogen peroxide as substrates. Here we demonstrate that HOCl alters metaphase-II mouse oocyte microtubules and chromosomal (CH) alignment which can be prevented by melatonin. Metaphase-II mouse oocytes, obtained commercially, were grouped as: control, melatonin (150, 200nmol/mL), HOCl (10, 20, 50, and 100nmol/mL), and HOCl (50nmol/mL) pretreated with 150 and 200 nmol/mL of melatonin. Microtubule and CH alignment was studied utilizing an indirect immunofluorescence technique and scored by two observers. Pearson chi-square test and Fisher's exact test were used to compare outcomes between controls and treated groups and also among each group. Poor scores for the spindle and chromosomes increased significantly at 50nmol/mL of HOCl (P<0.001). Oocytes treated with melatonin only at 150 and 200 nmol/mL showed no changes; significant differences (P<0.001) were observed when oocytes exposed to 50nmol/mL of HOCl were compared to oocytes pretreated with 200 nmol/mL melatonin. Fifty percent of the oocytes demonstrated good scores, both in microtubule and CH alterations, when pretreated with melatonin at 150 nmol/mL compared to 0% in the HOCl-only group. HOCl alters the metaphase-II mouse oocyte spindle and CH alignment in a dose-dependant manner, which might be a potential cause of poor oocyte quality (e.g., in patients with endometriosis). Melatonin prevented the HOCl-mediated spindle and CH damage, and therefore, may be an attractive therapeutic option to prevent oocyte damage in endometriosis or inflammatory diseases where HOCl levels are known to be elevated.

Trifolium species-derived substances and extracts--biological activity and prospects for medicinal applications

BACKGROUND

Despite of the fact that clovers (family: Fabaceae; genus: Trifolium) have been known for many centuries as important forage plants and valuable herbs in folk medicine, their phytochemical characteristics and biological activity remain only partly established.

AIM OF THE STUDY

The presentation of the current knowledge of physiological effects, therapeutic action, new trends in the investigation of Trifolium plants and suggestions for the future applications of these herbs in therapy of various disorders.

METHODS

A critical review of literature on the biological activity of Trifolium plants, with the indication on important gaps, was performed. The compilation of existing information on physiological effects and medicinal value of clovers, derived from both traditional medicine recommendations and scientific reports, is presented.

RESULTS

The available data indicate on the abundance of biologically active substances in Trifolium plants, including numerous flavonoids, saponins, clovamides and phenolic acids. The best known clover - Trifolium pratense L. (red clover) - is used for the production of herbal medicines, an alternative to the conventional hormonal replacement therapy. The biological activity and potential therapeutic effects of other Trifolium species have gained a considerable scientific interest; extracts obtained from various clovers have been shown to possess antioxidative and antiinflammatory activities, inhibiting angiogenesis and displaying anti-cancer properties.

CONCLUSIONS

Clovers other than T. pratense also seem to be a promising source of valuable phytochemicals, such as isoflavones and various flavonoids. However, the therapeutic use of these Trifolium species is significantly limited by the lack of clinical evidence; thus further studies are needed.

Association of bladder pain syndrome/interstitial cystitis with urinary calculus: a nationwide population-based study

INTRODUCTION AND HYPOTHESIS

Although one prior study reported an association between bladder pain syndrome/interstitial cystitis (BPS/IC) and urinary calculi (UC), no population-based study to date has been conducted to explore this relationship. Therefore, using a population-based data set in Taiwan, this study set out to investigate the association between BPS/IC and a prior diagnosis of UC.

METHODS

This study included 9,269 cases who had received their first-time diagnosis of BPS/IC between 2006 and 2007 and 46,345 randomly selected controls. We used conditional logistic regression analysis to compute the odds ratio (OR) and its corresponding 95 % confidence interval (CI) for having been previously diagnosed with UC between cases and controls.

RESULTS

There was a significant difference in the prevalence of prior UC between cases and controls (8.1 vs 4.3 %, p < 0.001). Conditional logistic regression analysis revealed that cases were more likely to have been previously diagnosed with UC than controls (OR = 1.70; 95 % CI = 1.56-1.84) after adjusting for chronic pelvic pain, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, depression, panic disorder, migraine, sicca syndrome, allergy, endometriosis, and asthma. BPS/IC was found to be significantly associated with prior UC regardless of stone location; the adjusted ORs of kidney calculus, ureter calculus, bladder calculus, and unspecified calculus when compared to controls were 1.58 (95 % CI = 1.38-1.81), 1.73 (95 % CI = 1.45-2.05), 3.80 (95 % CI = 2.18-6.62), and 1.83 (95 % CI = 1.59-2.11), respectively.

CONCLUSIONS

This work generates the hypothesis that UC may be associated with BPS/IC.

Poly(PS-b-DMA) micelles for reactive oxygen species triggered drug release

A new micelle drug carrier that consists of a diblock polymer of propylene sulfide (PS) and N,N-dimethylacrylamide (poly(PS₇₄-b-DMA₃₁₀)) has been synthesized and characterized for site-specific release of hydrophobic drugs to sites of inflammation. Propylene sulfide was first polymerized using a thioacyl group transfer (TAGT) method with the RAFT chain transfer agent (CTA) 4-cyano-4-(ethylsulfanylthiocarbonylsulfanyl) pentanoic acid (CEP), and the resultant poly(PS₇₄-CEP) macro-CTA was used to polymerize a second polymer block of DMA using reversible addition-fragmentation chain transfer (RAFT). The formation of the poly(PS₇₄-b-DMA₃₁₀) diblock polymer was confirmed by ¹H NMR spectra and gel permeation chromatography (GPC). Poly(PS₇₄-b-DMA₃₁₀) formed 100 nm micelles in aqueous media as confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Micelles loaded with the model drugs Nile red and DiO were used to demonstrate the ROS-dependent drug release mechanism of these micelles following treatment with hydrogen peroxide (H₂O₂), 3-morpholinosydnonimine (SIN-1), and peroxynitrite. These oxidants were found to oxidize the micelle PPS core, making it more hydrophilic and triggering micelle disassembly and cargo release. Delivery of poly(PS₇₄-b-DMA₃₁₀) micelles dual-loaded with the Förster Resonance Energy Transfer (FRET) fluorophore pair DiI and DiO was used to prove that endogenous oxidants generated by lipopolysaccharide (LPS)-treated RAW 264.7 macrophages significantly increased release of nanocarrier contents relative to macrophages that were not activated. In vitro studies also demonstrated that the poly(PS₇₄-b-DMA₃₁₀) micelles were cytocompatible across a broad range of concentrations. These combined data suggest that the poly(PS₇₄-b-DMA₃₁₀) micelles synthesized using a combination of TAGT and RAFT have significant potential for site-specific drug delivery to tissues with high levels of oxidative stress.

Interleukin-1α Induction in Human Keratinocytes (HaCaT): An In Vitro Model for Chemoprevention in Skin

Long-term exposure to UV irradiation and toxic chemicals is associated with chronic inflammation that contributes to skin cancer development with interleukin-1 alpha (IL-1α), constitutively produced by keratinocytes, playing a pivotal role in skin inflammation. The aim of this study was to investigate the modulation of IL-1α production in the HaCaT keratinocyte cell line. Phorbol 12-myristate 13-acetate failed to induce IL-1α in HaCaT cells, and this might be associated with the specific deficiency known to affect downstream signalling of the MEK/ERK pathway in these cells. The calcium ionophore, ionomycin, slightly enhanced the production of intracellular (icIL-1α), but this resulted in a necrotic release at higher concentrations. UV-B exposure significantly increased the production of icIL-1α in a dose-dependent manner with a maximal induction exhibited at 24 h with minimal necrotic and apoptotic effects. Validation of the HaCaT cell model indicated that the nonsteroidal anti-inflammatory drug (NSAID), ibuprofen, and the glucocorticoid, dexamethasone, inhibited icIL-1α production, and this was associated with a slight inhibition of cell viability. The UV-B-induced keratinocyte cell model provides an in vitro system that could, apart from phorbol ester-like compounds, be utilised as a screening assay in identifying skin irritants and/or therapeutic topical agents via the modulation of IL-1α production.

Hypohalous acid-mediated halogenation of resveratrol and its role in antioxidant and antimicrobial activities

The reactions of resveratrol with proinflammatory oxidants including hypochlorous and hypobromous acids in phosphate-buffered saline/methanol solution were carried out and eight halogenated resveratrol derivatives differing in the number and position of halogen atoms, and the configuration of double bond were obtained. Halogenation of resveratrol took place only at the aromatic A ring, and interestingly, the halogenation increased antioxidant activity of this parent molecule in the 2,2'-azobis(2-amidinopropane) hydrochloride-induced RBC haemolysis model. Additionally, antimicrobial activity of the derivatives against Gram-positive bacteria, Gram-negative bacteria and fungi were tested, and toward Candida albicans, 2-chloro-resveratrol and 2-bromo-resveratrol were more active than the unmodified form and the reference compound fluconazole.

Biological stimuli and biomolecules in the assembly and manipulation of nanoscale polymeric particles

Living systems are replete with complex, stimuli-responsive nanoscale materials and molecular self-assemblies. There is an ever increasing and intense interest within the chemical sciences to understand, mimic and interface with these biological systems utilizing synthetic and/or semi-synthetic tools. Our aim in this review is to give perspective on this emerging field of research by highlighting examples of polymeric nanoparticles and micelles that are prepared utilizing biopolymers together with synthetic polymers for the purpose of developing nanomaterials capable of interacting and responding to biologically relevant stimuli. It is expected that with the merging of evolved biological molecules with synthetic materials, will come the ability to prepare complex, functional devices. A variety of applications will become accessible including self-healing materials, self-replicating systems, biodiagnostic tools, drug targeting materials and autonomous, adaptive sensors. Most importantly, the success of this type of strategy will impact how biomolecules are stabilized and incorporated into synthetic devices and at the same time, will influence how synthetic materials are utilized within biomedical applications.

Delivery method, target gene structure, and growth properties of target cells impact mutagenic responses to reactive nitrogen and oxygen species

Dysregulated production of nitric oxide (NO•) and reactive oxygen species (ROS) by inflammatory cells in vivo may contribute to mutagenesis and carcinogenesis. Here, we compare cytotoxicity and mutagenicity induced by NO• and ROS in TK6 and AS52 cells, delivered by two methods: a well-characterized delivery system and a novel adaptation of a system for coculture. When exposed to preformed NO•, a cumulative dose of 620 μM min reduced the viability of TK6 cells at 24 h to 36% and increased mutation frequencies in the HPRT and TK1 genes to 7.7 × 10⁻⁶ (p < 0.05) and 24.8 × 10⁻⁶ (p < 0.01), 2.7- and 3.7-fold higher than background, respectively. In AS52 cells, cumulative doses of 1700 and 3700 μM min reduced viability to 49 and 22%, respectively, and increased the mutation frequency 10.2- and 14.6-fold higher than the argon control (132 × 10⁻⁶ and 190 × 10⁻⁶, respectively). These data show that TK6 cells were more sensitive than AS52 cells to killing by NO•. However, the two cell lines were very similar in relative susceptibility to mutagenesis; on the basis of fold increases in MF, average relative sensitivity values [(MF(exp)/MF(control))/cumulative NO• dose] were 5.16 × 10⁻³ and 4.97 × 10⁻³ μM⁻¹ min⁻¹ for TK6 cells and AS52 cells, respectively. When AS52 cells were exposed to reactive species generated by activated macrophages in the coculture system, cell killing was greatly reduced by the addition of NMA to the culture medium and was completely abrogated by combined additions of NMA and the superoxide scavenger Tiron, indicating the relative importance of NO• to loss of viability. Exposure in the coculture system for 48 h increased mutation frequency in the gpt gene by more than 9-fold, and NMA plus Tiron again completely prevented the response. Molecular analysis of gpt mutants induced by preformed NO• or by activated macrophages revealed that both doubled the frequency of gene inactivation (40% in induced vs 20% in spontaneous mutants). Sequencing showed that base-substitution mutations dominated the spectra, with transversions (30-40%) outnumbering transitions (10-20%). Virtually all mutations took place at guanine sites in the gene. G:C to T:A transversions accounted for about 30% of both spontaneous and induced mutations; G:C to A:T transitions amounted to 10-20% of mutants; insertions, small deletions, and multiple mutations were present at frequencies of 0-10%. Taken together, these results indicate that cell type and proximity to generator cells are critical determinants of cytotoxic and genotoxic responses induced by NO• and reactive species produced by activated macrophages.

Oxidative stress, endogenous antioxidants, alcohol, and hepatitis C: pathogenic interactions and therapeutic considerations

Hepatitis C virus (HCV) is a blood-borne pathogen that was identified as an etiologic agent of non-A, non-B hepatitis in 1989. HCV is estimated to have infected at least 170 million people worldwide. The majority of patients infected with HCV do not clear the virus and become chronically infected, and chronic HCV infection increases the risk for hepatic steatosis, cirrhosis, and hepatocellular carcinoma. HCV induces oxidative/nitrosative stress from multiple sources, including inducible nitric oxide synthase, the mitochondrial electron transport chain, hepatocyte NAD(P)H oxidases, and inflammation, while decreasing glutathione. The cumulative oxidative burden is likely to promote both hepatic and extrahepatic conditions precipitated by HCV through a combination of local and more distal effects of reactive species, and clinical, animal, and in vitro studies strongly point to a role of oxidative/nitrosative stress in HCV-induced pathogenesis. Oxidative stress and hepatopathogenesis induced by HCV are exacerbated by even low doses of alcohol. Alcohol and reactive species may have other effects on hepatitis C patients such as modulation of the host immune system, viral replication, and positive selection of HCV sequence variants that contribute to antiviral resistance. This review summarizes the current understanding of redox interactions of HCV, outlining key experimental findings, directions for future research, and potential applications to therapy.

Nitrative DNA damage induced by multi-walled carbon nanotube via endocytosis in human lung epithelial cells

Carbon nanotube (CNT) has a promising usage in the field of material science for industrial purposes because of its unique physicochemical property. However, intraperitoneal administration of CNT was reported to cause mesothelioma in experimental animals. Chronic inflammation may contribute to carcinogenesis induced by fibrous materials. 8-Nitroguanine is a mutagenic DNA lesion formed during inflammation and may play a role in CNT-induced carcinogenesis. In this study, we examined 8-nitroguanine formation in A549 human lung alveolar epithelial cells treated with multi-walled CNT (MWCNT) by fluorescent immunocytochemistry. Both MWCNTs with diameter of 20-30 nm (CNT20) and 40-70 nm (CNT40) significantly induced 8-nitroguanine formation at 5 and 10 μg/ml (p<0.05), which persisted for 24h, although there was no significant difference in DNA-damaging abilities of these MWCNTs. MWCNTs significantly induced the expression of inducible nitric oxide synthase (iNOS) for 24 h (p<0.05). MWCNTs also significantly increased the level of nitrite, a hydrolysis product of oxidized NO, in the culture supernatant at 4 and 8 h (p<0.05). MWCNT-induced 8-nitroguanine formation and iNOS expression were largely suppressed by inhibitors of iNOS (1400 W), nuclear factor-κB (Bay11-7082), actin polymerization (cytochalasin D), caveolae-mediated endocytosis (methyl-β-cyclodextrin, MBCD) and clathrin-mediated endocytosis (monodansylcadaverine, MDC). Electron microscopy revealed that MWCNT was mainly located in vesicular structures in the cytoplasm, and its cellular internalization was reduced by MBCD and MDC. These results suggest that MWCNT is internalized into cells via clathrin- and caveolae-mediated endocytosis, leading to inflammatory reactions including iNOS expression and resulting nitrative DNA damage, which may contribute to carcinogenesis.

1-Bromopropane up-regulates cyclooxygenase-2 expression via NF-κB and C/EBP activation in murine macrophages

1-Bromopropane (1-BP) has been used in industry as an alternative to ozone-depleting solvents. In the present study, we examined the effect of 1-BP on cyclooxygenase-2 (COX-2) gene expression and analyzed the molecular mechanism of its activity in murine RAW 264.7 macrophages. 1-BP dose-dependently increased COX-2 protein and mRNA levels, as well as COX-2 promoter-driven luciferase activity in macrophages. Additionally, exposure to 1-BP markedly enhanced the production of prostaglandin E(2) (PGE(2)), a major COX-2 metabolite, in macrophages. Transfection experiments with several human COX-2 promoter constructs revealed that 1-BP activated the transcription factors nuclear factor-κB (NF-κB) and CCAAT/enhancer-binding protein (C/EBP), but not AP-1 or the cyclic AMP response element binding protein. Furthermore, Akt and mitogen-activated protein (MAP) kinases were significantly activated by 1-BP. These results demonstrated that 1-BP induced COX-2 expression via NF-κB and C/EBP activation through the Akt/ERK and p38 MAP kinase pathways. These findings provide further insight into the signal transduction pathways involved in the inflammatory effects of 1-BP.

Asthma and risk of lung cancer

Asthma is a very common chronic disease that occurs in all age groups. Its high prevalence has significant health costs, which are even higher in the most severe disease forms. Lung cancer has the highest incidence of all cancers in the developed world and is an important cause of mortality. Patients with lung cancer are a big economic burden on health services, both in direct and indirect costs. Different authors suggest that atopic constitution, including different manifestations of allergy and asthma, are possible risk factors for lung cancer, above all in never-smokers. Given the high asthma prevalence and lung cancer incidence and mortality in developed countries, this association would have important public health implications. Uncertainties about the association and the underlying physiopathological mechanisms, however, seem to require further studies.

The association of diabetes mellitus with liver, colon, lung, and prostate cancer is independent of hypertension, hyperlipidemia, and gout in Taiwanese patients

Studies have shown an association between diabetes and cancer in Western countries; but this, as well as the influence of associated metabolic factors, must be confirmed by a prospective study in other population groups. This study aimed to investigate whether the strong association of cancer and diabetes is independent from the influence of hypertension, dyslipidemia, and gout in the Taiwanese population. A total of 985,815 study subjects were identified from the National Health Insurance in 1997 and followed up from 1998 to 2009. The demographic characteristics between patients with diabetes and cancer, including age, sex, hypertension, dyslipidemia, and gout, were analyzed using the χ(2) test. Cox proportional hazard regression models were used to determine the independent effects of diabetes on the risks of cancer. A total of 104,343 diabetic patients were followed up from 1998 to 2009. After adjusting for sex, age, hypertension, dyslipidemia, and gout, the incidences of cancer at any site and in the liver, colon, lungs, and prostate in diabetic patients were independently higher, with risk ratios of 1.56 (95% confidence interval [CI], 1.43-1.71), 1.67 (95% CI, 1.39-2.01), 1.75 (95% CI, 1.49-2.06), 1.54 (95% CI, 1.26-1.88), and 1.56 (95% CI, 1.19-2.04), respectively. Only breast cancer did not show any clinical significance. There was an increased incidence of cancer at any site in the diabetic patients compared with nondiabetic subjects. The most common cancers were liver, colon, lung, breast, and prostate cancer; and except for breast cancer, their incidences increased independently of hypertension, dyslipidemia, and gout in patients with diabetes.

Role of nitrative and oxidative DNA damage in inflammation-related carcinogenesis

Chronic inflammation induced by biological, chemical, and physical factors has been found to be associated with the increased risk of cancer in various organs. We revealed that infectious agents including liver fluke, Helicobacter pylori, and human papilloma virus and noninfectious agents such as asbestos fiber induced iNOS-dependent formation of 8-nitroguanine and 8-oxo-7, 8-dihydro-2′-deoxyguanosine (8-oxodG) in cancer tissues and precancerous regions. Our results with the colocalization of phosphorylated ATM and γ-H2AX with 8-oxodG and 8-nitroguanine in inflammation-related cancer tissues suggest that DNA base damage leads to double-stranded breaks. It is interesting from the aspect of genetic instability. We also demonstrated IL-6-modulated iNOS expression via STAT3 and EGFR in Epstein-Barr-virus-associated nasopharyngeal carcinoma and found promoter hypermethylation in several tumor suppressor genes. Such epigenetic alteration may occur by controlling the DNA methylation through IL-6-mediated JAK/STAT3 pathways. Collectively, 8-nitroguanine would be a useful biomarker for predicting the risk of inflammation-related cancers.

H₂O₂ production within tumor microenvironment inversely correlated with infiltration of CD56(dim) NK cells in gastric and esophageal cancer: possible mechanisms of NK cell dysfunction

Human NK cells can be divided into two subsets, CD56(dim)CD16(+)NK and CD56(bright)CD16(-)NK cells, based on their expression of CD56 and CD16. In the present study, we analyzed the relationship between CD56(dim)/CD56(bright) NK cells and H₂O₂ in tumor-infiltrating NK cells in patients with gastric (n = 50) and esophageal (n = 35) cancer. The ratio of CD56(dim) NK cells infiltrating tumors gradually decreased according to disease progression. H₂O₂ was abundantly produced within tumor microenvironments, and there was an inverse correlation between CD56(dim) NK cell infiltration and H₂O₂ production. CD56(dim) NK cells are more sensitive to apoptosis induced by physiological levels of H₂O₂ than CD56(bright) NK cells. Furthermore, the exposure of NK cells to H₂O₂ resulted in the impairment of ADCC activity. In conclusion, H₂O₂ produced within tumor microenvironments inversely correlated with the infiltration of CD56(dim) NK cells, possibly due to their preferentially induced cell death. These observations may explain one of the mechanisms behind NK cell dysfunction frequently observed in tumor microenvironments.

Hypochlorous acid-induced heme degradation from lactoperoxidase as a novel mechanism of free iron release and tissue injury in inflammatory diseases

Lactoperoxidase (LPO) is the major consumer of hydrogen peroxide (H₂O₂) in the airways through its ability to oxidize thiocyanate (SCN⁻) to produce hypothiocyanous acid, an antimicrobial agent. In nasal inflammatory diseases, such as cystic fibrosis, both LPO and myeloperoxidase (MPO), another mammalian peroxidase secreted by neutrophils, are known to co-localize. The aim of this study was to assess the interaction of LPO and hypochlorous acid (HOCl), the final product of MPO. Our rapid kinetic measurements revealed that HOCl binds rapidly and reversibly to LPO-Fe(III) to form the LPO-Fe(III)-OCl complex, which in turn decayed irreversibly to LPO Compound II through the formation of Compound I. The decay rate constant of Compound II decreased with increasing HOCl concentration with an inflection point at 100 µM HOCl, after which the decay rate increased. This point of inflection is the critical concentration of HOCl beyond which HOCl switches its role, from mediating destabilization of LPO Compound II to LPO heme destruction. Lactoperoxidase heme destruction was associated with protein aggregation, free iron release, and formation of a number of fluorescent heme degradation products. Similar results were obtained when LPO-Fe(II)-O₂, Compound III, was exposed to HOCl. Heme destruction can be partially or completely prevented in the presence of SCN⁻. On the basis of the present results we concluded that a complex bi-directional relationship exists between LPO activity and HOCl levels at sites of inflammation; LPO serve as a catalytic sink for HOCl, while HOCl serves to modulate LPO catalytic activity, bioavailability, and function.

XRCC1 and base excision repair balance in response to nitric oxide

Inflammation associated reactive oxygen and nitrogen species (RONs), including peroxynitrite (ONOO(-)) and nitric oxide (NO), create base lesions that potentially play a role in the toxicity and large genomic rearrangements associated with many malignancies. Little is known about the role of base excision repair (BER) in removing these endogenous DNA lesions. Here, we explore the role of X-ray repair cross-complementing group 1 (XRCC1) in attenuating RONs-induced genotoxicity. XRCC1 is a scaffold protein critical for BER for which polymorphisms modulate the risk of cancer. We exploited CHO and human glioblastoma cell lines engineered to express varied levels of BER proteins to study XRCC1. Cytotoxicity and the levels of DNA repair intermediates (single-strand breaks; SSB) were evaluated following exposure of the cells to the ONOO(-) donor, SIN-1, and to gaseous NO. XRCC1 null cells were slightly more sensitive to SIN-1 than wild-type cells. We used small-scale bioreactors to expose cells to NO and found that XRCC1-deficient CHO cells were not sensitive. However, using a molecular beacon assay to test lesion removal in vitro, we found that XRCC1 facilitates AAG-initiated excision of two key NO-induced DNA lesions: 1,N(6)-ethenoadenine and hypoxanthine. Furthermore, overexpression of AAG rendered XRCC1-deficient cells sensitive to NO-induced DNA damage. These results show that AAG is a key glycosylase for BER of NO-induced DNA damage and that XRCC1's role in modulating sensitivity to RONs is dependent upon the cellular level of AAG. This demonstrates the importance of considering the expression of other components of the BER pathway when evaluating the impact of XRCC1 polymorphisms on cancer risk.

Signaling in H2O2-induced increase in cell proliferation in Barrett's esophageal adenocarcinoma cells

Mechanisms whereby acid reflux may accelerate the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. We have previously shown that NADPH oxidase NOX5-S generates reactive oxygen species (ROS) when Barrett's metaplastic cells are exposed to acid. Besides metaplastic cells, other H(2)O(2)-producing cells (e.g., inflammatory cells) present in BE mucosa may produce additional ROS, which may also affect metaplastic cells contributing to esophageal tumorigenesis. In this study, we investigate whether exogenous H(2)O(2) stimulates cell proliferation by increasing NOX5-S expression. Low dose (10(-13) M) of H(2)O(2) significantly increased thymidine incorporation, NOX5-S mRNA, and protein expression in a Barrett's EA cell line FLO. H(2)O(2)-induced increase in NOX5-S expression was significantly inhibited by knockdown of nuclear factor (NF)-κB1 p50 with p50 small interfering RNA (siRNA) in EA cell lines FLO and OE33. H(2)O(2) significantly increased p65 phosphorylation and the luciferase activity in FLO cells transfected with a NF-κB activation reporter plasmid pNF-κB-Luc. H(2)O(2)-induced increase in luciferase activity in FLO cells was significantly decreased by knockdown of extracellular signal-regulated kinase 2 (ERK2) mitogen-activated protein kinase (MAPK). Overexpression of p50 and p65 remarkably increased the luciferase activity in FLO cells transfected with a NOX5-S reporter plasmid NOX5-LP. In addition, H(2)O(2)-induced thymidine incorporation in FLO cells was significantly decreased by the MAPK kinase 1/2 inhibitor 2'-amino-3'methoxyflavone (PD98059) and ERK2 siRNA but not by ERK1 siRNA. Likewise, H(2)O(2)-induced increase in NOX5-S expression was significantly decreased by ERK2 siRNA in FLO and OE33 cells. We conclude that a low dose of H(2)O(2) increases cell proliferation. H(2)O(2)-induced increase in cell proliferation may depend on sequential activation of ERK2 MAPK, NF-κB1 p50, and NOX5-S.

Reproductive benefit of oxidative damage: an oxidative stress "malevolence"?

High levels of reactive oxygen species (ROS) compared to antioxidant defenses are considered to play a major role in diverse chronic age-related diseases and aging. Here we present an attempt to synthesize information about proximate oxidative processes in aging (relevant to free radical or oxidative damage hypotheses of aging) with an evolutionary scenario (credited here to Dawkins hypotheses) involving tradeoffs between the costs and benefits of oxidative stress to reproducing organisms. Oxidative stress may be considered a biological imperfection; therefore, the Dawkins' theory of imperfect adaptation of beings to environment was applied to the role of oxidative stress in processes like famine and infectious diseases and their consequences at the molecular level such as mutations and cell signaling. Arguments are presented that oxidative damage is not necessarily an evolutionary mistake but may be beneficial for reproduction; this may prevail over its harmfulness to health and longevity in evolution. Thus, Dawkins' principle of biological “malevolence” may be an additional biological paradigm for explaining the consequences of oxidative stress.

Tumor microenvironment is multifaceted

Cancer initiation, progression, and invasion occur in a complex and dynamic microenvironment which depends on the hosts and sites where tumors develop. Tumors arising in mucosal tissues may progress in an inflammatory context linked to local viral and/or bacterial infections. At the opposite, tumors developing in immunoprivileged sites are protected from microorganisms and grow in an immunosuppressive environment. In the present review, we summarize and present our recent data on the influence of infectious context and immune cell infiltration organization in human Non-Small Cell Lung Cancers (NSCLC) progression. We show that stimulation of tumor cells by TLR for viral ssRNA, such as TLR7/8, or bacteria, such as TLR4, promotes cell survival and induces chemoresistance. On the opposite, stimulation by TLR3, receptor for double-stranded viral RNA, decreases tumor cell viability and induces chemosensitivity in some lung tumor cell lines. Since fresh lung tumor cells exhibit a gene expression profile characteristic of TLR-stimulated lung tumor cell lines, we suspect that viral and bacterial influence may not only act on the host immune system but also directly on tumor growth and sensitivity to chemotherapy. The stroma of NSCLC contains tertiary lymphoid structures (or Tumor-induced Bronchus-Associated Lymphoid Tissues (Ti-BALT)) with mature DC, follicular DC, and T and B cells. Two subsets of immature DC, Langerhans cells (LC) and interstitial DC (intDC), were detected in the tumor nests and the stroma, respectively. Here, we show that the densities of the three DC subsets, mature DC, LC, and intDC, are highly predictive of disease-specific survival in a series of 74 early-stage NSCLC patients. We hypothesize that the mature DC may derive from local activation and migration of the immature DC--and especially LC which contact the tumor cells--to the tertiary lymphoid structures, after sampling and processing of the tumor antigens. In view of the prominent role of DC in the immune response, we suggest that the microenvironment of early-stage NSCLC may allow the in situ activation of the adaptive response. Finally, we find that the eyes or brain of mice with growing B cell lymphoma are infiltrated with T cells and that the cytokines produced ex vivo by the tumoral tissues have an impaired Th1 cytokine profile. Our work illustrates that the host and external tumor microenvironments are multifaceted and strongly influence tumor progression and anti-tumor immune responses.

Evaluation of the anti-inflammatory and anti-tumor effect of Ipomoea obscura (L) and its mode of action through the inhibition of proinflammatory cytokines, nitric oxide and COX-2

Ipomoea obscura (L) is a widely used medicinal plant. In this study, we investigated its anti-inflammatory and anti-tumor effect using in vitro and in vivo models. Methanolic extract of I. obsucra (10 mg/kg b.wt) was given interaperitoneally before inducing inflammation (both acute and chronic) and tumor to mice. I. obscura produced significant inhibition of 55.6%, 42%, and 65% in the paw edema of animals induced by carrageenan, dextran, and formalin respectively. The extract was also a potent inhibitor of lipopolysaccharide (LPS)-induced NO, CRP, and proinflammatory cytokine production via gene expression in peritoneal macrophages. TNF-α production by macrophage culture treated with LPS was found to be significantly inhibited by I. obscura. The extract was 100% toxic at a concentration of 500 µg/mL for both Dalton's lymphoma ascites (DLA) and Ehrlich ascites carcinoma (EAC) cells. The extract was also found to inhibit tumor cell proliferation in a dose and time-dependent manner. It could also inhibit solid tumor development in mice induced with DLA cells and increased life span of mice bearing EAC tumor to 83% and 53.8%, respectively. This anti-inflammatory effect of the extract is assumed to result mainly from the inhibition of some key enzymes and mediators involved in the inflammation and/or cell signaling pathways such as iNOS, COX-2, and proinflammatory cytokines. This anti-inflammatory property might be the reason for its anti-tumor effects.

Studies on the synthesis and the antimicrobial and antioxidant activities of a novel class of fluorescein-based glycosides

Facile glycosylation of a fluorescein diol derivative with per-O-acetyl/benzoyl sugar derivatives using BF(3)·Et(2)O catalyst resulted in the formation of the expected glycosides in 54-66% yield. The biological screening of the glycosides against different microbes shows good inhibitory activity. The antioxidant activity of the fluorescein-based glycosides shows remarkable inhibition (IC(50) ∼80%).