Inflammation, a key event in cancer development

Molecular targets of nutraceuticals derived from dietary spices: potential role in suppression of inflammation and tumorigenesis

Despite the fact cancer is primarily a preventable disease, recent statistics indicate cancer will become the number one killer worldwide in 2010. Since certain cancers are more prevalent in the people of some countries than others, suggests the role of lifestyle. For instance cancer incidence among people from the Indian subcontinent, where most spices are consumed, is much lower than that in the Western World. Spices have been consumed for centuries for a variety of purposes-as flavoring agents, colorants, and preservatives. However, there is increasing evidence for the importance of plant-based foods in regular diet to lowering the risk of most chronic diseases, so spices are now emerging as more than just flavor aids, but as agents that can not only prevent but may even treat disease. In this article, we discuss the role of 41 common dietary spices with over 182 spice-derived nutraceuticals for their effects against different stages of tumorigenesis. Besides suppressing inflammatory pathways, spice-derived nutraceuticals can suppress survival, proliferation, invasion, and angiogenesis of tumor cells. We discuss how spice-derived nutraceuticals mediate such diverse effects and what their molecular targets are. Overall our review suggests "adding spice to your life" may serve as a healthy and delicious way to ward off cancer and other chronic diseases.

Phenylmethimazole decreases Toll-like receptor 3 and noncanonical Wnt5a expression in pancreatic cancer and melanoma together with tumor cell growth and migration

PURPOSE

To evaluate whether (a) Wnt5a expression in pancreatic cancer and malignant melanoma cells might be associated with constitutive levels of Toll-like receptor 3 (TLR3) and/or TLR3 signaling; (b) phenylmethimazole (C10), a novel TLR signaling inhibitor, could decrease constitutive Wnt5a and TLR3 levels together with cell growth and migration; and (c) the efficacy of C10 as a potential inhibitor of pancreatic cancer and malignant melanoma cell growth in vivo.

EXPERIMENTAL DESIGN

We used a variety of molecular biology techniques including but not limited to PCR, Western blotting, and ELISA to evaluate the presence of constitutively activated TLR3/Wnt5a expression and signaling. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-based technology and scratch assays were used to evaluate inhibition of cell growth and migration, respectively. TLR3 regulation of cell growth was confirmed using small interfering RNA technology. Nude and severe combined immunodeficient mice were implanted with human pancreatic cancer and/or melanoma cells and the effects of C10 on tumor growth were evaluated.

RESULTS

We show that constitutive TLR3 expression is associated with constitutive Wnt5a in human pancreatic cancer and malignant melanoma cell lines, that C10 can decrease constitutive TLR3/Wnt5a expression and signaling, suggesting that they are interrelated signal systems, and that C10 inhibits growth and migration in both of these cancer cell lines. We also report that C10 is effective at inhibiting human pancreatic cancer and malignant melanoma tumor growth in vivo in nude or severe combined immunodeficient mice and associate this with inhibition of signal transducers and activators of transcription 3 activation.

CONCLUSIONS

C10 may have potential therapeutic applicability in pancreatic cancer and malignant melanoma.

Validation of human papillomavirus genotyping by signature DNA sequence analysis

BACKGROUND

Screening with combined cytologic and HPV testing has led to the highest number of excessive colposcopic referrals due to high false positive rates of the current HPV testing in the USA. How best to capitalize on the enhanced sensitivity of HPV DNA testing while minimizing false-positive results from its lower specificity is an important task for the clinical pathologists.

METHODS

The HPV L1 gene DNA in liquid-based Pap cytology specimens was initially amplified by the degenerate MY09/MY11 PCR primers and then re-amplified by the nested GP5+/GP6+ primers, or the heminested GP6/MY11, heminested GP5/MY09 primers or their modified equivalent without sample purification or DNA extraction. The nested PCR products were used for direct automated DNA sequencing. A 34- to 50-base sequence including the GP5+ priming site was selected as the signature sequence for routine genotyping by online BLAST sequence alignment algorithms.

RESULTS

Of 3,222 specimens, 352 were found to contain HPV DNA, with 92% of the positive samples infected by only 1 of the 35 HPV genotypes detected and 8% by more than 1 HPV genotype. The most common genotype was HPV-16 (68 isolates), followed by HPV-52 (25 isolates). More than half (53.7%) of the total number of HPV isolates relied on a nested PCR for detection although the majority of HPV-16, -18, -31, -33 -35 and -58 isolates were detected by a single MY09/MY11 PCR. Alignment of a 34-base sequence downstream of the GP5+ site failed to distinguish some isolates of HPV-16, -31 and -33. Novel variants of HPV with less than "100% identities" signature sequence match with those stored in the Genbank database were also detected by signature DNA sequencing in this rural and suburban population of the United States.

CONCLUSION

Laboratory staff must be familiar with the limitations of the consensus PCR primers, the locations of the signature sequence in the L1 gene for some HPV genotypes, and HPV genotype sequence variants in order to perform accurate HPV genotyping.

C-reactive protein haplotype is associated with high PSA as a marker of metastatic prostate cancer but not with overall cancer risk

Growing evidence points to a role for inflammation in prostate carcinogenesis. The significance of C-reactive protein (CRP), an inflammatory and innate immunity molecule, has not been evaluated thoroughly in prostate cancer (PC). In this study of 739 Finnish patients with PC and 760 healthy men, we evaluated the associations of CRP genotypes and haplotypes with total PC risk and PC progression, using prostate-specific antigen (PSA) as a marker of metastatic disease. Although the haplotype frequencies were similar in patients and controls, an association between haplotype ACCCA and patients' PSA levels was found. The carriers more often had a high PSA than non-carriers (P=0.0002) and the SNP rs2794521 A-allele and rs1800947 C-allele carriers had a higher PSA than non-carriers (P=0.009 and P=0.0004, respectively). A trend for a younger age at diagnosis was found among the carriers of ACCCA (P=0.07) and the rs1800947 C-allele (P=0.06), as well as a trend for the latter to have more likely metastases (P=0.06), but not after Bonferroni correction (α=0.00208). This is the first study to suggest association between PSA and CRP variants in PC and, therefore, further studies are warranted. CRP alleles previously found to protect against increased CRP levels are now suggested to be associated with metastatic PC, indicated by elevated PSA.

Expression of stem cell factor and its receptor c-Kit during the development of intrahepatic cholangiocarcinoma

Stem cell factor (SCF) and its receptor, c-Kit, constitute an important signal transduction system with proliferative and anti-apoptotic functions. Besides regulating hemopoietic stem cell proliferation and liver regeneration, it has been implicated in the regulation of human malignancies. However, the cellular expression of the SCF-c-Kit gene system in the liver during cholangiocarcinogenesis has not been studied to date. The protein- and mRNA-expression levels of SCF and c-Kit genes were examined in normal rat liver, in isolated normal rat liver cells and in a thioacetamide-induced rat model of intrahepatic cholangiocarcinoma (CC). Immunohistochemical analysis of the normal liver showed that SCF is expressed in the wall of the hepatic artery and in some cells, which were located along the sinusoids, although it was absent from hepatocytes and biliary epithelial cells. The mRNA analysis of isolated normal liver cell populations revealed a co-expression of SCF- and c-Kit-mRNA in sinusoidal endothelial cells and in Kupffer cells, whereas passaged and cultured liver myofibroblasts (MFs) expressed only SCF. Low levels of the SCF- and c-Kit-mRNA expression could be detected in isolated hepatocytes of the normal liver. Immunohistochemical analysis of the CC tissue showed SCF positivity in proliferating biliary cells (CK-19(+)), in macrophages (ED-1(+)) and in MFs (alpha-smooth-muscle-actin, alpha-SMA(+)) of the tumoral microenvironment. c-Kit-positivity could be detected on hepatocytes of the regenerating nodules and on the proliferating bile ducts of CC. Compared with the normal liver tissue, SCF-mRNA from the CC tissue was upregulated up to 20-fold, whereas c-Kit-mRNA was upregulated up to fivefold. These data indicate that several cell populations may become able to express SCF and/or c-Kit during cholangiocarcinogenesis. Therefore, the SCF-c-Kit system may contribute to tumor development, for instance, by inducing proliferation of hepatocytes and of biliary cells and by acting as a surviving factor for CC cells.

The association of atopic diseases with breast, prostate, and colorectal cancers: a meta-analysis

There is a long-standing interest in finding whether allergic disorders cause or prevent cancer. We meta-analyzed associations of allergies with prostate, breast, and colorectal cancers. We searched MEDLINE, EMBASE, and Web of Science between 1966 and 2008 and eligible reference lists. A total of 16 observational studies were included. Meta-analyses revealed no evidence that asthma, hay fever, or 'any allergy' are associated with cancers of the breast (relative risk, RR = 0.93, 95% CI: 0.73-1.19 for asthma; 1.04, 0.94-1.16 for hay fever; 1.01, 0.94-1.08 for any allergy); prostate (RR = 0.93, 95% CI: 0.76-1.15 for asthma; 0.96, 0.87-1.05 for hay fever; 1.01, 0.87-1.17 for any allergy); or colorectum (RR = 0.95, 95% CI: 0.77-1.16 for asthma; 0.95, 0.86-1.05 for hay fever; 0.94, 0.85-1.04 for any allergy). There was a positive association of atopy (assessed by allergen-specific IgE or skin prick testing) with prostate cancer (RR = 1.43, 95% CI: 1.08-1.91), but not breast (1.18, 0.90-1.55) or colorectal (1.32, 0.69-2.53) cancers. There is little epidemiological support for the immune surveillance theory or antigenic stimulation theory in breast or colorectal carcinogenesis. The findings for prostate cancer warrant further investigation.

Prevention of proliferative changes of forestomach mucosa by blood glucose control with insulin in alloxan-induced diabetic rats

Diabetes mellitus is one of the risk factors for carcinogenesis. Recently we reported that alloxan induces squamous cell carcinoma (SCC) with coincidental inflammation, bacteria/fungal infections, and a severe diabetic condition. The present study was conducted to examine the effects of blood glucose control with insulin on the proliferative changes of the forestomach in alloxan-induced diabetic rats. Male 15-week-old WBN/Kob rats were divided into a control group of non-treated rats with naturally occurring diabetes after 40 weeks of age (non-treated group), alloxan-induced diabetic rats (AL group), and alloxan-induced diabetic rats given insulin implant treatment (AL + In group). The animals were sacrificed at 90 weeks of age for histopathologic examination. The blood glucose and urinary glucose level of the AL + In group fluctuated variously from high to normal levels compared with a constantly high level of AL (for 75 weeks) as well as in the non-treated group (for 50 weeks). The mucosal hyperplasia in the forestomach developed in 88.2% of the AL group and 37.5% of the non-treated group, but in only 10.0% of the AL + In group. SCC was only detected in 23.5% of the AL group. Hyperplastic changes were constantly accompanied by inflammation and fungal/bacterial infections in the AL and non-treated groups, whereas inflammation and fungal infection were completely suppressed in the AL + In group. These findings demonstrate that blood glucose control suppressed neoplastic changes in alloxan-induced diabetic rats. We postulate that inflammation together with bacterial/fungal infections under prolonged severe diabetic conditions play a pivotal role in carcinogenesis.

Role of T-lymphocytes and pro-inflammatory mediators in the pathogenesis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the US and a major worldwide healthcare problem. The pathophysiologic mechanisms that drive development and progression of this disease are complex and only poorly understood. While tobacco smoking is the primary risk factor, other disease processes also appear to play a role. Components of the innate immune system (eg, macrophages and neutrophils) have long been believed to be important in the development of COPD. More recent evidence also suggests involvement of the adaptive immune system in pathogenesis of this disease. Here we will review the literature supporting the participation of T-cells in the development of COPD, and comment on the potential antigenic stimuli that may account for these responses. We will further explore the prospective contributions of T-cell derived mediators that could contribute to the inflammation, alveolar wall destruction, and small airway fibrosis of advanced COPD. A better understanding of these complex immune processes will lead to new insights that could result in improved preventative and/or treatment strategies.

Mining metastasis related genes by primary-secondary tumor comparisons from large-scale databases

Background

Metastasis is the most dangerous step in cancer progression and causes more than 90% of cancer death. Although many researchers have been working on biological features and characteristics of metastasis, most of its genetic level processes remain uncertain. Some studies succeeded in elucidating metastasis related genes and pathways, followed by predicting prognosis of cancer patients, but there still is a question whether the result genes or pathways contain enough information and noise features have been controlled appropriately.

Methods

We set four tumor type classes composed of various tumor characteristics such as tissue origin, cellular environment, and metastatic ability. We conducted a set of comparisons among the four tumor classes followed by searching for genes that are consistently up or down regulated through the whole comparisons.

Results

We identified four sets of genes that are consistently differently expressed in the comparisons, each of which denotes one of four cellular characteristics respectively – liver tissue, colon tissue, liver viability and metastasis characteristics. We found that our candidate genes for tissue specificity are consistent with the TiGER database. And we also found that the metastasis candidate genes from our method were more consistent with the known biological background and independent from other noise features.

Conclusion

We suggested a new method for identifying metastasis related genes from a large-scale database. The proposed method attempts to minimize the influences from other factors except metastatic ability including tissue originality and tissue viability by confining the result of metastasis unrelated test combinations.

Glutathione peroxidases in different stages of carcinogenesis

Cancer cells produce high amounts of reactive oxygen species (ROS) and evade apoptosis. Hydroperoxides support proliferation, invasion, migration and angiogenesis, but at higher levels induce apoptosis, thus being pro- and anti-carcinogenic. Accordingly, glutathione peroxidases (GPxs) regulating hydroperoxide levels might have dual roles too. GPx1, clearly an antioxidant enzyme, is down-regulated in many cancer cells. Its main role would be prevention of cancer initiation by ROS-mediated DNA damage. GPx2 is up-regulated in cancer cells. GPx1/GPx2 double knockout mice develop colitis and intestinal cancer. However, GPx2 knockdown cancer cells grow better in vitro and in vivo probably reflecting the physiological role of GPx2 in intestinal mucosa homeostasis. GPx2 counteracts COX-2 expression and PGE(2) production, which explains its potential to inhibit migration and invasion of cultured cancer cells. Overexpression of GPx3 inhibits tumor growth and metastasis. GPx4 is decreased in cancer tissues. GPx4-overexpressing cancer cells have low COX-2 activity and tumors derived therefrom are smaller than from control cells and do not metastasize. Collectively, GPxs prevent cancer initiation by removing hydroperoxides. GPx4 inhibits but GPx2 supports growth of established tumors. Metastasis, but also apoptosis, is inhibited by all GPxs. GPx-mediated regulation of COX/LOX activities may be relevant to early stages of inflammation-mediated carcinogenesis.

Serum concentrations of cytokines and lung cancer survival in African Americans and Caucasians

Accumulating evidence suggests a role for inflammation in the development and progression of cancer. Our group recently identified a cytokine gene signature in lung tissue associated with lung cancer prognosis. Therefore, we hypothesized that concentrations of circulating cytokines in serum may be associated with lung cancer survival. Ten serum cytokines, namely, interleukin (IL)-1beta, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, granulocyte macrophage colony-stimulating factor, interferon (IFN)-gamma, and tumor necrosis factor-alpha, were assessed in 353 non-small cell lung cancer cases from a case-control study of lung cancer in the greater Baltimore, Maryland area. Cytokines were measured using an ultrasensitive electrochemiluminescence immunoassay. IL-6 serum concentrations (>or=4.0 pg/mL) were associated with significantly poorer survival in both African Americans [hazard ratio (HR), 2.71; 95% confidence interval (CI), 1.26-5.80] and Caucasians (HR, 1.71; 95% CI, 1.22-2.40). IL-10 (HR, 2.62; 95% CI, 1.33-5.15) and IL-12 (HR, 1.98; 95% CI, 1.14-3.44) were associated with lung cancer survival only in African Americans. Some evidence for an association of tumor necrosis factor-alpha levels with survival in Caucasians was observed, although these results were not significant. These hypothesis-generating findings indicate that selected serum cytokine concentrations are associated with lung cancer survival, and indicate that further research is warranted to better understand the mechanistic underpinnings of these associations.

Chronic Mycobacterium marinum infection acts as a tumor promoter in Japanese Medaka (Oryzias latipes)

An accumulating body of research indicates there is an increased cancer risk associated with chronic infections. The genus Mycobacterium contains a number of species, including M. tuberculosis, which mount chronic infections and have been implicated in higher cancer risk. Several non-tuberculosis mycobacterial species, including M. marinum, are known to cause chronic infections in fish and like human tuberculosis, often go undetected. The elevated carcinogenic potential for fish colonies infected with Mycobacterium spp. could have far reaching implications because fish models are widely used to study human diseases. Japanese medaka (Oryzias latipes) is an established laboratory fish model for toxicology, mutagenesis, and carcinogenesis; and produces a chronic tuberculosis-like disease when infected by M. marinum. We examined the role that chronic mycobacterial infections play in cancer risk for medaka. Experimental M. marinum infections of medaka alone did not increase the mutational loads or proliferative lesion incidence in all tissues examined. However, we showed that chronic M. marinum infections increased hepatocellular proliferative lesions in fish also exposed to low doses of the mutagen benzo[a]pyrene. These results indicate that chronic mycobacterial infections of medaka are acting as tumor promoters and thereby suggest increased human risks for cancer promotion in human populations burdened with chronic tuberculosis infections.

Pleomorphic Corneal Sarcoma Resembling Malignant Peripheral Nerve Sheath Tumor in a Horse

A 14-year-old Haflinger gelding presented with a protruding mass involving the cornea of the right eye. The mass was resected and submitted for histopathologic and immunohistochemical examination. The preliminary diagnosis was corneal sarcoma, most likely fibrosarcoma. The immunohistochemical results confirmed the mesenchymal origin of the neoplastic cells, which were most consistent with a malignant peripheral nerve sheath tumor. Corneal mesenchymal neoplasms are extremely uncommon tumors in human beings and domestic animals. The cause for this tumor was not determined; infection with bovine papillomavirus was not detected.

Methylation of polycomb target genes in intestinal cancer is mediated by inflammation

Epigenetic changes are strongly associated with cancer development. DNA hypermethylation is associated with gene silencing and is often observed in CpG islands. Recently, it was suggested that aberrant CpG island methylation in tumors is directed by Polycomb (PcG) proteins. However, specific mechanisms responsible for methylation of PcG target genes in cancer are not known. Chronic infection and inflammation contribute to up to 25% of all cancers worldwide. Using glutathione peroxidase, Gpx1 and Gpx2, double knockout (Gpx1/2-KO) mice as a model of inflammatory bowel disease predisposing to intestinal cancer, we analyzed genome-wide DNA methylation in the mouse ileum during chronic inflammation, aging, and cancer. We found that inflammation leads to aberrant DNA methylation in PcG target genes, with 70% of the approximately 250 genes methylated in the inflamed tissue being PcG targets in embryonic stem cells and 59% of the methylated genes being marked by H3K27 trimethylation in the ileum of adult wild-type mice. Acquisition of DNA methylation at CpG islands in the ileum of Gpx1/2-KO mice frequently correlates with loss of H3K27 trimethylation at the same loci. Inflammation-associated DNA methylation occurs preferentially in tissue-specific silent genes and, importantly, is much more frequently represented in tumors than is age-dependent DNA methylation. Sixty percent of aberrant methylation found in tumors is also present in the inflamed tissue. In summary, inflammation creates a signature of aberrant DNA methylation, which is observed later in the malignant tissue and is directed by the PcG complex.

Serum amyloid A: an acute-phase protein involved in tumour pathogenesis

The synthesis of acute-phase protein serum amyloid A (SAA) is largely regulated by inflammation- associated cytokines and a high concentration of circulating SAA may represent an ideal marker for acute and chronic inflammatory diseases. However, SAA is also synthesized in extrahepatic tissues, e.g. human carcinoma metastases and cancer cell lines. An increasing body of in vitro data supports the concept of involvement of SAA in carcinogenesis and neoplastic diseases. Accumulating evidence suggests that SAA might be included in a group of biomarkers to detect a pattern of physiological events that reflect the growth of malignancy and host response. This review is meant to provide a broad overview of the many ways that SAA could contribute to tumour development, and accelerate tumour progression and metastasis, and to gain a better understanding of this acute-phase reactant as a possible link between chronic inflammation and neoplasia.

Breast cancer by proxy: can the microenvironment be both the cause and consequence?

Breast cancer is one of the most clear-cut examples of a solid tumor in which systemic cues play a decisive part in its development. The breast tissue is constantly subjected to changes in hormone levels and modifications in the microenvironment. This scenario is even more striking during tumor development because of the dramatic loss or aberration of basement membrane (BM) and myoepithelial cells and the gain of peritumoral myofibroblasts. We suggest that the microenvironment, defined here as all components of the mammary gland other than luminal and/or tumor epithelial cells, might be instrumental in maintaining organ integrity and in promoting, and at times even initiating, breast cancer development. As such, the tumor microenvironment and its constituents, alone or in combination, might serve as promising targets for therapy.

Past medical conditions and K-ras mutations in pancreatic ductal adenocarcinoma: a hypothesis-generating study

BACKGROUND

In pancreatic ductal adenocarcinoma (PDA) evidence on the etiopathogenic role of past medical conditions in the occurrence and persistence of K-ras mutations is scant.

METHODS

Incident cases of PDA were interviewed face-to-face about past medical history and other factors. Logistic regression was used to compare PDA cases (n = 120) with wild-type and mutated K-ras tumors (case-case study).

RESULTS

Patients with wild-type K-ras tumors were more likely to have a prior diagnosis of pancreatitis (Odds ratio [OR] = 6.11, p = 0.041). Diabetes mellitus (DM) was non-significantly more common among cases with a K-ras wild-type tumor, and the OR for DM of >6 years of duration was 4.54 (p = 0.39). Patients with wild-type K-ras were significantly more likely to have had a surgically treated peptic ulcer (OR = 9.03, p = 0.027). The probability of having a K-ras wild-type tumor increased with the number of medical conditions (p for trend = 0.012); the corresponding OR for two or more medical conditions was 4.46 (95% CI: 1.37-14.50).

CONCLUSIONS

Results raise the hypothesis that pancreatitis and possibly peptic ulcer might influence pancreatic carcinogenesis through pathways independent of K-ras mutation, perhaps related to growth factors or mediators of the inflammatory response. Large unselected studies should be conducted to refute or replicate our findings.

The association of interleukin-16 polymorphisms with IL-16 serum levels and risk of colorectal and gastric cancer

Interleukin (IL)-16, a multifunctional cytokine, plays a fundamental role in inflammatory diseases, as well as in the development and progression of tumors. Genetic variation in the DNA sequence of the IL-16 gene may lead to altered cytokine production and/or activity, and this variation may modulate an individual's susceptibility to both colorectal cancer (CRC) and gastric cancer (GC). To test this hypothesis, we investigated the association of IL-16 gene polymorphisms with serum levels of IL-16 and the risk of CRC and GC in a Chinese population. We analyzed single-nucleotide polymorphisms of the IL-16 gene in 596 cancer patients (376 patients with CRC and 220 patients with GC), and also in 480 age- and sex-matched controls using polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. Serum IL-16 levels were measured by enzyme-linked immunosorbent assay. The rs11556218 T/G polymorphism of the IL-16 gene was significantly associated with the susceptibility to CRC and GC patients. Both male and female patients carrying the G allele had a significantly higher risk for developing CRC and GC compared with individuals carrying the T allele. Alternatively, women carrying the T allele (rs4072111 C/T) showed a decreased risk for CRC and GC compared with individuals carrying the C allele. In patients with CRC or GC, IL-16 serum levels were significantly higher than those in the healthy controls, although no significant association between IL-16 polymorphisms and serum levels of IL-16 was observed. Our data indicate that IL-16 polymorphisms may contribute to CRC and GC susceptibility.

Examination of hypochlorous acid-induced damage to cytosine residues in a CpG dinucleotide in DNA

Inflammation-mediated, neutrophil-derived hypochlorous acid can damage DNA and result in the chlorination damage products 5-chlorocytosine and 5-chlorouracil as well as the oxidation damage products 5-hydroxycytosine and 5-hydroxyuracil. While 5-chlorocytosine could potentially perturb epigenetic signals if formed at a CpG dinucleotide, the remaining products are miscoding and could result in transition mutations. In this article, we have investigated the reaction of hypochlorous acid with an oligonucleotide site-specifically enriched with 15N to probe the reactivity of cytosine at CpG. These experiments demonstrate directly the formation of 5-chlorocytosine at a CpG dinucleotide in duplex DNA. We observe that chlorination relative to oxidation damage is greater at CpG by a factor of approximately two, whereas similar amounts of 5-chlorocytosine and 5-hydroxycytosine are formed at two non-CpG sites examined. The relative amounts of deamination of the cytosine to uracil derivatives are similar at CpG and non-CpG sites. Overall, we observe that the reactivity of cytosine at CpG and non-CpG sites toward hypochlorous acid induced damage is similar (5-chlorocytosine > 5-hydroxycytosine > 5-hydroxyuracil > 5-chlorouracil), with a greater proportion of chlorination damage at CpG sites. These results are in accord with the potential of inflammation-mediated DNA damage to both induce transition mutations and to perturb epigenetic signals.

Imaging spontaneous tumorigenesis: inflammation precedes development of peripheral NK tumors

Early events in tumor development are spontaneous, microscopic, and affected by the microenvironment. We developed a mouse model of spontaneous lymphoma in which malignant transformation is coupled with light emission that can be detected noninvasively using bioluminescent imaging. The human T-cell leukemia virus (HTLV) type 1 transcriptional transactivator Tax is an oncogene sufficient to produce lymphoma in transgenic animal models. Using the granzyme B promoter to restrict Tax expression to the mature natural killer (NK)/T-cell compartment, we have reproduced many elements of HTLV-associated adult T-cell leukemia/lymphoma. Tax activates signaling cascades associated with transformation, inflammation, and tumorigenesis. Here, we report that Tax-mediated activation of luciferase in long terminal repeat-luciferase (LTR-LUC) mice serves as a reporter for imaging these processes in vivo. Using bioluminescent imaging (BLI), we discovered that microscopic intraepithelial lesions precede the onset of peripheral subcutaneous tumors, tumorigenesis progresses through early reversible stages, and Tax is sufficient for inducing tumors. Based on these findings, we propose that Tax expression in activated lymphocytes initiates a cascade of events that leads to NK/T cell recruitment, activation, and transformation. The use of BLI expands our ability to interrogate the role of Tax in tumorigenesis in vivo and has made the association of inflammation with tumor initiation amenable for study.

Promotion of lung carcinogenesis by chronic obstructive pulmonary disease-like airway inflammation in a K-ras-induced mouse model

Lung cancer is the leading cause of cancer deaths in the United States. In addition to genetic abnormalities induced by cigarette smoke, several epidemiologic studies have found that smokers with chronic obstructive pulmonary disease (COPD), an inflammatory disease of the lungs, have an increased risk of lung cancer (1.3- to 4.9-fold) compared to smokers without COPD. This suggests a link between chronic airway inflammation and lung carcinogenesis, independent of tobacco smoke exposure. We studied this association by assaying the inflammatory impact of products of nontypeable Haemophilus influenzae, which colonizes the airways of patients with COPD, on lung cancer promotion in mice with an activated K-ras mutation in their airway epithelium. Two new mouse models of lung cancer were generated by crossing mice harboring the LSL-K-ras(G12D) allele with mice containing Cre recombinase inserted into the Clara cell secretory protein (CCSP) locus, with or without the neomycin cassette excised (CCSP(Cre) and CCSP(Cre-Neo), respectively). Lung lesions in CCSP(Cre-Neo)/LSL-K-ras(G12D) and CCSP(Cre)/LSL-K-ras(G12D) mice appeared at 4 and 1 month of age, respectively, and were classified as epithelial hyperplasia of the bronchioles, adenoma, and adenocarcinoma. Weekly exposure of CCSP(Cre)/LSL-K-ras(G12D) mice to aerosolized nontypeable Haemophilus influenzae lysate from age 6-14 weeks resulted in neutrophil/macrophage/CD8 T-cell-associated COPD-like airway inflammation, a 3.2-fold increase in lung surface tumor number (156 +/- 9 versus 45 +/- 7), and an increase in total lung tumor burden. We conclude that COPD-like airway inflammation promotes lung carcinogenesis in a background of a G12D-activated K-ras allele in airway secretory cells.

Synergistic effect of combination of phenethyl isothiocyanate and sulforaphane or curcumin and sulforaphane in the inhibition of inflammation

PURPOSE

Accumulating evidence from epidemiologic and clinical studies indicates that chronic inflammatory disorders harbor an increased risk of cancer development. Curcumin (CUR) has been strongly linked to the anti-inflammatory effect. On the other hand, isothiocyanates such as sulforaphane (SFN) and phenethyl isothiocyanate (PEITC) are strong phase-II detoxifying/antioxidant enzymes inducer. Therefore it is interesting to see if combination of these drugs can inhibit inflammation with higher combined efficacies.

METHODS

We used nitric oxide (NO) assay to assess the synergism of the different combinations of CUR, SFN and PEITC. The inflammatory markers, e.g. iNOS, COX-2, prostaglandin E2 (PGE2), tumor necrosis factor (TNF) and interleukin-1 (IL-1) levels were determined using RT-PCR, Western blot and ELISA assays.

RESULTS

We report that combination of PEITC + SFN or CUR + SFN has a synergistic effect in down-regulating inflammation markers like TNF, IL-1, NO, PGE2. The synergism is probably due to the synergistic induction of phase II/antioxidant enzymes including heme-oxygenase1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1).

CONCLUSIONS

Our data suggest that CUR + SFN and PEITC + SFN combinations could be more effective than used alone in preventing inflammation and possibly its associated diseases including cancer.

Dietary Lactoferrin Does Not Prevent Dextran Sulfate Sodium Induced Murine Intestinal Lymphocyte Death

Dextran sulfate sodium (DSS) induced intestinal inflammation is characterized by pronounced mucosal and epithelial cell damage. Bovine lactoferrin (bLf), a common dietary protein, influences inflammatory cytokines and intestinal lymphocyte (IL) apoptosis. The objectives of this study were to determine if 1) DSS induces IL necrotic or apoptotic death, 2) dietary bLf affects DSS induced IL death and 3) bLf alters cytokine profiles during DSS induced inflammation. Female C57BL/6 mice were randomized to 2% or 0% bLf diets for 12 d and within diets to 5% or 0% DSS in the drinking water for 4 d after which intestinal histology, IL number, IL apoptosis/necrosis, IL phenotypes, protein levels of pro-inflammatory cytokine (TNF-α) and transcription factor (NFκB), apoptotic (caspase 3, Bax) proteins, anti-inflammatory cytokine (IL-10) and anti-apoptotic (Bcl-2) protein in IL were evaluated. DSS treatment resulted in shortened intestinal length, decreased body weight and widespread mucosal damage as well as increased IL death as determined by a decreased percentage of viable (PI−/ANN−, P < 0.005) and increased percentage of necrotic/late apoptotic (PI+/ ANN+, P < 0.05) and necrotic (PI+/ANN−, P < 0.05) IL. DSS exposure increased caspase 3 ( P < 0.05) and decreased Bcl-2 ( P < 0.01) protein levels in mouse IL. Dietary bLf did not influence these cell death outcome measures. However, bLf reduced protein levels of the pro-inflammatory transcription factor, NFκB, in IL ( P < 0.05) and was associated with a 34%, albeit non-significant, reduction in TNF-α relative to non-bLf fed mice. DSS treatment increased apoptosis and necrosis of mouse IL and elevated pro-apoptotic and reduced anti-apoptotic protein levels in these cells. Dietary bLf did not influence necrosis or apoptosis of IL but may provide limited protection in the intestine by affecting the pro-inflammatory transcription factor NFκB, and potentially, cytokine expression.

Nonmelanoma skin cancer and risk for subsequent malignancy

BACKGROUND

Individuals with a personal history of nonmelanoma skin cancer (NMSC) may have an increased risk of subsequent noncutaneous malignancies. To test this hypothesis, we carried out a community-based, prospective cohort study.

METHODS

In the CLUE (Give Us a Clue to Cancer and Heart Disease) II cohort, which was established in Washington County, MD, in 1989, the risk of new malignancies was compared among individuals with (n = 769) and without (n = 18,405) a personal history of NMSC (total n = 19,174) during a 16-year follow-up period. Pathologically confirmed NMSC (and other malignancies) were ascertained from the Washington County Cancer Registry. Cox regression analysis with time-dependent covariates was used to determine the hazard ratios (presented as multivariable-adjusted relative risks [RRs]) and 95% confidence intervals (CIs) of second primary malignancies associated with a previously confirmed NMSC diagnosis. All statistical tests were two-sided.

RESULTS

The crude incidence rate (per 10,000 person-years) of subsequent cancers other than NMSC among participants with a positive personal history of NMSC was 293.5 and with a negative history was 77.8. Compared with persons with no personal history of NMSC, those with such a history had a statistically significantly increased risk of being diagnosed with a subsequent cancer other than NMSC (RR = 1.99, 95% CI = 1.70 to 2.33) after adjusting for age, sex, body mass index, smoking status, and educational level. The association was observed for both basal cell carcinoma (multivariable-adjusted RR = 2.03, 95% CI = 1.70 to 2.42) and squamous cell carcinoma (multivariable-adjusted RR = 1.97, 95% CI = 1.50 to 2.59) of the skin. NMSC was a statistically significantly stronger cancer risk factor in younger age groups than in older age groups (P for interaction = .022).

CONCLUSIONS

This community-based, prospective cohort study provides evidence for an association between an NMSC diagnosis and an increased risk of subsequent cancer, even after adjusting for individual-level risk factors.

Associations of circulating C-reactive protein and interleukin-6 with cancer risk: findings from two prospective cohorts and a meta-analysis

OBJECTIVE

We investigated the associations of circulating C-reactive protein (CRP) and interleukin-6 (IL-6) with cancer risk.

METHODS

We examined the associations of CRP and IL-6 with incident cancer in two prospective cohorts, the British Women's Heart and Health Study (4,286 women aged 60-80) and the Caerphilly Cohort (2,398 men aged 45-59) using Cox regression and pooled our findings with previous prospective studies' in fixed and random effects meta-analyses.

RESULTS

CRP and IL-6 were associated with some incident cancers in our cohorts, but the numbers of cancer cases were small. In our meta-analyses elevated CRP was associated with an increased overall risk of cancer (random effects estimate (RE): 1.10, 95% CI: 1.02, 1.18) and lung cancer (RE: 1.32, 95% CI: 1.08, 1.61). Its associations with colorectal (RE: 1.09, 95% CI: 0.98, 1.21) and breast cancer risks (RE: 1.10, 95% CI: 0.97, 1.26) were weaker. CRP appeared unrelated to prostate cancer risk (RE: 1.00 0.88, 1.13). IL-6 was associated with increased lung and breast cancer risks and decreased prostate cancer risk, and was unrelated to colorectal cancer risk.

CONCLUSIONS

Our findings suggest an etiological role for CRP and IL-6 in some cancers. Further large prospective and genetic studies would help to better understand this role.

Malleable immunoglobulin genes and hematopathology - the good, the bad, and the ugly: a paper from the 2007 William Beaumont hospital symposium on molecular pathology

Immunoglobulin gene rearrangement analysis is one of the more commonly performed assays available on the hematopathology menu of clinical molecular pathology laboratories. The analysis of these rearrangements provides useful information on a number of different levels in the evaluation of lymphoproliferations. An appreciation of the various mechanisms involved in the numerous physiological pathways affecting the immunoglobulin genes, and hence antibody molecules, is central to an understanding of B-cell development vis-à-vis the generation of immunological diversity. Knowledge about the intricate complexities of these mechanisms is also germane to an evaluation of testing methodologies. With this information, it is easier to develop an understanding of how contemporary molecular testing of immunoglobulin gene rearrangements has evolved, from historically quite heterogeneous, fairly flawed, and rather ugly approaches to current more-standardized protocols. In addition, recognition of how such genetic changes with good intentions can turn bad has fostered increasing insights into the pathogenesis of B-cell lymphomas and leukemias. Despite the significant improvements in the design of immunoglobulin gene rearrangement assays, numerous pitfalls and caveats remain. Accordingly, it is crucial to consider such testing a tool, and although most useful, it is one of many tools that may be required to build cogent diagnoses.

Interpreting crosstalk between TNF-alpha and NGF: potential implications for disease

Tumour necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine, whereas nerve growth factor (NGF) is a neurotrophin that can promote neural cell survival, differentiation and maturation. However, recent papers indicate that TNF-alpha has a pivotal role in fate decisions of neural cells in normal noninflammatory conditions, whereas NGF contributes to maintenance of inflammation. Although these observations suggest a close relationship between NGF and TNF-alpha signalling, crosstalk between these factors is not fully understood. In this Opinion article, we review recent reports regarding possible crosstalk between NGF and TNF-alpha and we propose a positive-feedback loop of their expression. We discuss the possible mechanisms by which disturbance of the crosstalk could contribute to diseases such as cancer and Alzheimer's disease.

Cancer chemoprevention and chemotherapy: dietary polyphenols and signalling pathways

Prevention of cancer through dietary intervention recently has received an increasing interest, and dietary polyphenols have become not only important potential chemopreventive, but also therapeutic, natural agents. Polyphenols have been reported to interfere at the initiation, promotion and progression of cancer. They might lead to the modulation of proteins in diverse pathways and require the integration of different signals for the final chemopreventive or therapeutic effect. Polyphenols have been demonstrated to act on multiple key elements in signal transduction pathways related to cellular proliferation, differentiation, apoptosis, inflammation, angiogenesis and metastasis; however, these molecular mechanisms of action are not completely characterized and many features remain to be elucidated. The aim of this review is to provide insights into the molecular basis of potential chemopreventive and therapeutic activities of dietary polyphenols with emphasis in their ability to control intracellular signalling cascades considered as relevant targets in a cancer preventive approach.

Overexpression of CXCL16 and its receptor CXCR6/Bonzo promotes growth of human schwannomas

Chemokines and their receptors play a decisive role in tumor progression and metastasis. Here, we describe the expression of the CXCL16-CXCR6-system in human schwannomas of different localization and in malignant peripheral nerve sheath tumors. The transmembrane chemokine CXCL16 and its receptor CXCR6/Bonzo were overexpressed on the mRNA and protein levels in all tumor samples investigated as compared with normal peripheral or 8th cranial nerve tissues. Chromogenic immunostaining and confocal laser microscopy revealed that CXCL16 and CXCR6 were localized mainly on S-100 positive schwannoma cells. Cultured schwannoma cells responded to CXCL16-stimulation by phosphorylation of kinases p42/44 (Erk 2/1) that could be inhibited by the MEK1/2-inhibitor U0126 indicating an involvement of the mitogen-activated protein kinase signal transduction pathway. As a biological response, CXCL16 increased proliferation and induced migration of schwannomas. Hence, CXCL16 appears to be a novel growth factor for schwannomas of different localization.

Profiling of genetic variations in inflammation pathway genes in relation to bladder cancer predisposition

PURPOSE

Compelling evidence has indicated that inflammation plays an important role in cancer development. We sought to test the hypothesis that common sequence variants in the inflammation pathway modulate bladder cancer risk.

EXPERIMENTAL DESIGN

We genotyped 59 potentially functional single nucleotide polymorphisms from 35 candidate inflammation genes in a case-control study including 635 Caucasian bladder cancer patients and 635 matched controls.

RESULTS

The most significant finding was in the 3'-untranslated region of PTGS2 (exon10+837T>C, rs5275), which was associated with a significantly reduced risk (odds ratio, 0.68; 95% confidence interval, 0.54-0.87; P=0.002) and remained significant after multiple comparison adjustment. Consistently, the most common PTGS2 haplotype containing the common allele of exon10+837T>C was associated with a significantly increased risk (odds ratio, 1.27; 95% confidence interval, 1.06-1.52; P=0.008). In contrast, the haplotypes containing at least one variant allele of exon10+837T>C were all associated with a decreased risk. In a combined analysis to assess the cumulative effects of inflammation single nucleotide polymorphisms on bladder cancer risk, we found that in the anti-inflammation pathway, but not in the proinflammation pathway, when compared with individuals with a few adverse alleles, individuals with more adverse alleles had a significantly increased risk in a dose-dependent manner (P(trend)=0.012). To further elucidate the functional mechanism of these associations, we redefined the adverse alleles based on literature-reported functional results and found that individuals with a higher number of inflammation-enhancing alleles in the anti-inflammation pathway exhibited a greater bladder cancer risk.

CONCLUSIONS

Our results strongly suggest that common variants in inflammation genes affect bladder cancer susceptibility individually and jointly.

Proliferative inflammatory atrophy: a background lesion of prostate cancer?

Proliferative inflammatory atrophy (PIA) belongs to the atrophic lesions that frequently occur in the prostate. The location of PIA in the periphery of the gland near to prostate carcinoma or even showing direct transition to malignant or pre-malignant epithelia suggested a connection between PIA and prostate cancer. Further findings in PIA, such as imbalance between proliferation and apoptosis and detection of molecular-biological abnormalities specific for oxidative stress or malignancy, supported this hypothesis. Recently, epidemiological studies including large cohorts of patients have been undertaken in order to investigate the causal connection between PIA and prostate carcinoma. The current understanding of PIA allows us to consider it as a benign lesion with certain genetic instability which can degenerate into prostate intraepithelial neoplasia or carcinoma, provided that the balance between anti-carcinogens and carcinogens is perturbed. To evaluate the role of PIA as a precursor lesion of prostate cancer, further examinations of genetic or epigenetic aberrations are required.

Higher levels of the anti-inflammatory protein CC10 are associated with improvement in bronchial dysplasia and sputum cytometric assessment in individuals at high risk for lung cancer

PURPOSE

CC10, a 10-kDa anti-inflammatory protein secreted by bronchiolar Clara cells, is infrequently expressed in non-small cell lung cancer and its overexpression in non-small cell lung cancer cell lines results in a less malignant phenotype. Several lines of evidence have shown that bronchial dysplasia and sputum atypia are predictors of lung cancer. We investigated whether changes in CC10 expression correlate with regression of bronchial dysplasia and/or improvement in sputum abnormalities as measured by image cytometry.

EXPERIMENTAL DESIGN

High-risk smokers enrolled in a chemoprevention trial underwent serial bronchoscopies with biopsies and bronchoalveolar lavage (BAL) collection, sputum assessment by image cytometry, and blood collection. CC10 was measured by competitive ELISA in BAL and plasma. Logistic regression analyses were done to determine the associations between CC10 levels and the improvement in bronchial dysplasia and sputum cytometric assessment.

RESULTS

The net change in the BAL CC10 levels in subjects with improved bronchial lesions or improved sputum cytometry assessment was significantly higher than in those without improvement (P < 0.05). The odds ratio (95% confidence interval) associated with 1-unit increase in CC10 was 2.72 (1.31-5.64) for regression of dysplastic lesions and 2.94 (1.22-7.05) for improvement in sputum cytometry assessment after multivariate adjustment. Plasma CC10 was not significantly associated with either outcome.

CONCLUSIONS

Higher BAL CC10 levels are significantly correlated with regression of bronchial dysplasia and improvement in sputum cytometry assessment in smokers with high lung cancer risk. Whether CC10 levels can predict clinical outcomes among high-risk populations warrants further investigation.

The TWEAK-Fn14 cytokine-receptor axis: discovery, biology and therapeutic targeting

TWEAK is a multifunctional cytokine that controls many cellular activities including proliferation, migration, differentiation, apoptosis, angiogenesis and inflammation. TWEAK acts by binding to Fn14, a highly inducible cell-surface receptor that is linked to several intracellular signalling pathways, including the nuclear factor-kappaB (NF-kappaB) pathway. The TWEAK-Fn14 axis normally regulates various physiological processes, in particular it seems to play an important, beneficial role in tissue repair following acute injury. Furthermore, recent studies have indicated that TWEAK-Fn14 axis signalling may contribute to cancer, chronic autoimmune diseases and acute ischaemic stroke. This Review provides an overview of TWEAK-Fn14 axis biology and summarizes the available data supporting the proposal that both TWEAK and Fn14 should be considered as potential targets for the development of novel therapeutics.

Antioxidant effects of green tea and its polyphenols on bladder cells

Genitourinary tract inflammation/ailments affect the quality of life and health of a large segment of society. In recent years, studies have demonstrated strong antioxidant effects of green tea and its associated polyphenols in inflammatory states. This in vitro study examined the antioxidant capabilities (and putative mechanisms of action) of green tea extract (GTE), polyphenon-60 (PP-60, 60% pure polyphenols), (-)-epicatechin-3-gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) in normal/malignant human bladder cells following catechin treatment+/-1 mM H2O2 (oxidative agent). Cell viability, apoptosis and reactive oxygen species (ROS) formation were evaluated. Our results showed that H2O2 exposure significantly reduced normal (UROtsa) and high-grade (TCCSUP, T24) bladder cancer (BlCa) cell viability compared with control-treated cells (p<0.001). No affect on low-grade RT4 and SW780 BlCa cell viability was observed with exposure to H2O2. Compared to H2O2-treated UROtsa, treatment with PP-60, ECG and EGCG in the presence of H2O2 significantly improved UROtsa viability (p<0.01), with strongest effects evoked by ECG. Additionally, though not as effective as in UROtsa cells, viability of both high-grade TCCSUP and T24 BlCa cells, in comparison to H2O2-treated cells, was significantly improved (p<0.01) by treatment with PP-60, ECG, and EGCG in the presence of H2O2. Overall, our findings demonstrate that urothelium cell death via H2O2-induced oxidative stress is mediated, in part, through superoxide (O2-.;), and potentially, direct H2O2 mechanisms, suggesting that green tea polyphenols can protect against oxidative stress/damage and bladder cell death.

Systematic review of the association between circulating interleukin-6 (IL-6) and cancer

Our aim was to systematically review the epidemiologic evidence for an association of circulating interleukin-6 (IL-6), an inflammatory cytokine and cancer. We systematically searched electronic databases Embase, Medline and Web of Science for the studies of circulating IL-6 and any form of cancer. We identified and reviewed 189 discrete studies, consisting of 177 prevalent studies and three prospective studies. Cancer patients' IL-6 concentrations were higher than healthy controls' in most studies, but the results of investigations comparing IL-6 in cancer patients and individuals with benign diseases were less consistent. Due to the small number of prospective studies it is impossible to determine whether IL-6 is causally related to cancer. Large prospective studies of circulating IL-6 or studies using the functional variants of the IL-6 gene as instruments for circulating IL-6 concentrations would provide information on possible aetiological links between IL-6 and malignancy.

Genetic aspects of inflammation and cancer

Chronic inflammation is involved in the pathogenesis of most common cancers. The aetiology of the inflammation is varied and includes microbial, chemical and physical agents. The chronically inflamed milieu is awash with pro-inflammatory cytokines and is characterized by the activation of signalling pathways that cross-talk between inflammation and carcinogenesis. Many of the factors involved in chronic inflammation play a dual role in the process, promoting neoplastic progression but also facilitating cancer prevention. A comprehensive understanding of the molecular and cellular inflammatory mechanisms involved is vital for developing preventive and therapeutic strategies against cancer. The purpose of the present review is to evaluate the mechanistic pathways that underlie chronic inflammation and cancer with particular emphasis on the role of host genetic factors that increase the risk of carcinogenesis.

Gene expression profile of prostate cancer cell lines: effect of nerve growth factor treatment

A dysregulation of the nerve growth factor (NGF)-mediated control of prostate cell growth is associated with the malignant progression of prostate epithelial cells. Exogenous NGF induced in prostate cancer (PCa) cell lines DU145 and PC3 the expression of p75(NGFR), accompanied by a reduction of the cell malignancy. The aim of this study was to analyze the profile of NGF-regulated genes the PCa cell line DU145 by using the cDNA microarray technique. NGF treatment of DU145 cells decreased the expression of 52 known genes, while the expression of 40 known genes was increased. NGF treatment of the DU145 cell line modified the expression profile of clusters of genes involved in invasion and metastasis, in cell proliferation and apoptosis, inflammation, cell metabolism and transcriptional activity. Interestingly, NGF induced the same pattern of gene modifications in both PCa cell lines. Data presented here may help to identify gene/proteins that dispose to PCa progression and to assess future markers that could allow the development of new clinic diagnostic and therapeutical approaches.

Modifying effects of IL-6 polymorphisms on body size-associated breast cancer risk

OBJECTIVE

The association between obesity and breast cancer risk is complex. We examined whether the association between body size and breast cancer risk is modified by interleukin-6 (IL6) genotype.

METHODS AND PROCEDURES

Five polymorphisms in the IL-6 gene (rs1800797/-596A>G, rs1800796/-572G>C, rs1800795/-174G>C, rs2069832/IVS2G>A, and rs2069849 exon 5 C>T) were studied. We investigated IL6 genotypes and haplotypes with indicators of body size among non-Hispanic white (NHW) and Hispanic/American Indian (AI) breast cancer cases and controls living in the Southwestern United States.

RESULTS

We observed lower mean levels of BMI among NHW women who carried one or two copies of the GGCAC haplotype (in order: rs1800797, rs1800796, rs1800795, rs2069832, and rs2069849; P trend 0.02). This haplotype, with an estimated frequency of 43% in NHW study controls, was considerably less common in Hispanic/AI controls (19%). We did not detect significant interactions between IL6 genotypes or haplotypes and BMI categorized as low/normal (<25), overweight (25 to <30), or obese (> or =30) and breast cancer risk in either NHW or Hispanic/AI women. However, we detected consistent and significant interactions between waist-to-hip ratio (WHR) and IL6 rs1800795/-174 G>C genotype for breast cancer risk. These associations were restricted to postmenopausal NHW women. Among women without recent hormone exposure, those with a WHR >0.9 and the rs1800795 GG genotype had a greater than threefold increased risk of breast cancer (odds ratios (ORs) 3.22, 95% confidence intervals (CIs) 1.27, 817) when compared with women with a WHR <0.8 and the rs1800795 GG genotype (P interaction 0.01).

DISCUSSION

These data suggest that IL-6 genotypes may influence breast cancer risk in conjunction with central adiposity.

Chronic inflammation and pancreatic cancer

There is a proven association between carcinoma of the pancreas and both the sporadic and hereditary forms of chronic pancreatitis. In chronic pancreatitis the standardised incidence ratio for development of pancreatic cancer is 14-18 and is further increased by cigarette smoking. Underlying mechanisms are unclear but current theories point to the progressive accumulation of genetic mutations as a consequence of repeated DNA damage and cell regeneration in an environment favouring proliferation and neovascularisation. In patients who develop pancreatic cancer, there is interest in the role of the inflammatory response in the development of cancer cachexia and in determining prognosis. Furthermore, markers of a systemic inflammatory response have prognostic significance in both advanced, inoperable pancreatic cancer and in patients undergoing resection. Further understanding of the details of the relationship between inflammation, carcinogenesis and cancer prognosis may lead to new therapeutic possibilities as part of multi-modality management of this difficult disease.

Epstein-Barr virus lytic transactivator Zta enhances chemotactic activity through induction of interleukin-8 in nasopharyngeal carcinoma cells

Epstein-Barr virus (EBV)-associated, undifferentiated type of nasopharyngeal carcinoma (NPC) is characterized by intensive leukocyte infiltration. Interaction between the infiltrating cells and the tumor cells has been considered crucial for NPC development. Recruitment of the infiltrates can be directed by certain chemokines present in the NPC tissues. It is unknown whether and how EBV lytic infection regulates expression of the chemokines. Using an antibody array, we first found that several chemokines secreted from EBV-infected NPC cells are increased upon EBV reactivation into the lytic cycle, and interleukin-8 (IL-8) is the chemokine upregulated most significantly and consistently. Further studies showed that the EBV lytic transactivator Zta is a potent inducer of IL-8 in NPC cells, augmenting secreted and intracellular IL-8 proteins, as well as IL-8 RNA. Zta upregulates Egr-1, a cellular transcription factor that has been involved in upregulation of IL-8, but the Zta-induced IL-8 expression is independent of Egr-1. The ability of Zta to transactivate the IL-8 promoter is important for the induction of IL-8, and we have identified two Zta-responsive elements in the promoter. Zta can bind to these two elements in vitro and can also be recruited to the IL-8 promoter in vivo. DNA-binding-defective Zta mutants can neither activate the IL-8 promoter nor induce IL-8 production. In addition, Zta-expressing NPC cells exert enhanced chemotactic activity that is mainly mediated by IL-8. Since IL-8 may contribute to not only leukocyte infiltration but also multiple oncogenic processes, the present study provides a potential link between EBV lytic infection and pathogenesis of NPC.

NF-kappaB/p65 antagonizes Nrf2-ARE pathway by depriving CBP from Nrf2 and facilitating recruitment of HDAC3 to MafK

Constitutively activated NF-kappaB occurs in many inflammatory and tumor tissues. Does it interfere with anti-inflammatory or anti-tumor signaling pathway? Here, we report that NF-kappaB p65 subunit repressed the Nrf2-antioxidant response element (ARE) pathway at transcriptional level. In the cells where NF-kappaB and Nrf2 were simultaneously activated, p65 unidirectionally antagonized the transcriptional activity of Nrf2. In the p65-overexpressing cells, the ARE-dependent expression of heme oxygenase-1 was strongly suppressed. However, p65 inhibited the ARE-driven gene transcription in a way that was independent of its own transcriptional activity. Two mechanisms were found to coordinate the p65-mediated repression of ARE: (1) p65 selectively deprives CREB binding protein (CBP) from Nrf2 by competitive interaction with the CH1-KIX domain of CBP, which results in inactivation of Nrf2. The inactivation depends on PKA catalytic subunit-mediated phosphorylation of p65 at S276. (2) p65 promotes recruitment of histone deacetylase 3 (HDAC3), the corepressor, to ARE by facilitating the interaction of HDAC3 with either CBP or MafK, leading to local histone hypoacetylation. This investigation revealed the participation of NF-kappaB p65 in the negative regulation of Nrf2-ARE signaling, and might provide a new insight into a possible role of NF-kappaB in suppressing the expression of anti-inflammatory or anti-tumor genes.

Anti-inflammatory and analgesic potency of carboxyamidotriazole, a tumorostatic agent

Carboxyamidotriazole (CAI) is a calcium influx inhibitor that is undergoing clinical trials for the treatment of various human cancers following the identification of its antiproliferative and antimetastatic activities. The exact mechanism of its action is not clearly understood, and whether it has other functions besides the established antitumor activity has not been reported either. In the present study, we demonstrate for the first time that CAI possesses anti-inflammatory and analgesic activities using a variety of animal models, including croton oil-induced ear edema, cotton-induced granuloma, rat adjuvant-induced arthritis, acetic acid-induced writhing, and the formalin test. We also show that CAI significantly inhibits local vascular permeability stimulated by vascular endothelial growth factor or histamine and decreases tumor necrosis factor-alpha and interleukin-1beta levels at the site of inflammation and in serums, which may contribute to the anti-inflammatory effect. These data suggest that CAI is a promising anti-inflammatory and analgesic agent, and they provide new insight into the biological activity of the drug.

Bisphosphonate-associated osteonecrosis can hide jaw metastases

BACKGROUND

Osteonecrosis of the jaw is a well known potential complication of bisphosphonate treatment but its pathogenesis is poorly understood. The current management of patients with bisphosphonate-associated osteonecrosis (BON) is based on "expert recommendations" and there is a recognized need of better evidence. We report two cases where BON hid jaw metastases and use them to discuss some limitations of the current recommendations.

PATIENTS

Two patients undergoing long-term I.V. amino-bisphosphonate treatment for metastatic cancer presented with areas of intraorally exposed jawbone. Bisphosphonate-associated osteonecrosis was diagnosed on the basis of medical history, clinical and radiological features. They underwent surgical resection of the affected jaw due to unrelenting pain and lack of response to conservative treatments.

RESULTS

Histological examination of the surgical specimen revealed cancer cells at the margins of the site of osteonecrosis. Our patients did not undergo bone biopsy according to current recommendations, due to lack of clinical and radiological signs suggestive of jaw metastases.

CONCLUSIONS

Our findings show that: i) patients with BON may also have jaw metastases; ii) there may not be clinical or imaging hints to this fact and; iii) that a biopsy based on careful selection of the site (with inclusion of necrotic margins) may be needed to reach the correct diagnosis. Further studies should be performed on this topic because of its very important prognostic implications.

Clinically relevant immunosuppressants influence UVB-induced tumor size through effects on inflammation and angiogenesis

Immunosuppressive therapies allow long-term patient and transplant survival, but are associated with increased development of UV-induced skin cancers, particularly squamous cell carcinomas. The mechanisms by which CsA, MMF, tacrolimus (TAC) or sirolimus (SRL), alone or in dual combinations, influence tumor development and progression are not completely understood. In the current study, chronically UV-exposed mice treated with SRL alone or in combination with CsA or TAC developed more tumors than mice treated with vehicle or other immunosuppressants, but the tumors were significantly smaller and less advanced. Mice treated with CsA or TAC developed significantly larger tumors than vehicle-treated mice, and a larger percentage in the CsA group were malignant. The addition of MMF to CsA, but not to TAC, significantly reduced tumor size. Immunosuppressant effects on UVB-induced inflammation and tumor angiogenesis may explain these findings. CsA enhanced both UVB-induced inflammation and tumor blood vessel density, while MMF reduced inflammation. Addition of MMF to CsA reduced tumor size and vascularity. SRL did not affect inflammation, but significantly reduced tumor vascularity. Thus the choice of immunosuppressants has important implications for tumor number, size and progression, likely due to the influence of immunosuppressants on UVB-induced inflammation and angiogenesis.

Chronic inflammation and oxidative stress in human carcinogenesis

A wide array of chronic inflammatory conditions predispose susceptible cells to neoplastic transformation. In general, the longer the inflammation persists, the higher the risk of cancer. A mutated cell is a sine qua non for carcinogenesis. Inflammatory processes may induce DNA mutations in cells via oxidative/nitrosative stress. This condition occurs when the generation of free radicals and active intermediates in a system exceeds the system's ability to neutralize and eliminate them. Inflammatory cells and cancer cells themselves produce free radicals and soluble mediators such as metabolites of arachidonic acid, cytokines and chemokines, which act by further producing reactive species. These, in turn, strongly recruit inflammatory cells in a vicious circle. Reactive intermediates of oxygen and nitrogen may directly oxidize DNA, or may interfere with mechanisms of DNA repair. These reactive substances may also rapidly react with proteins, carbohydrates and lipids, and the derivative products may induce a high perturbation in the intracellular and intercellular homeostasis, until DNA mutation. The main substances that link inflammation to cancer via oxidative/nitrosative stress are prostaglandins and cytokines. The effectors are represented by an imbalance between pro-oxidant and antioxidant enzyme activities (lipoxygenase, cyclooxygenase and phospholipid hydroperoxide glutathione-peroxidase), hydroperoxides and lipoperoxides, aldehydes and peroxinitrite. This review focalizes some of these intricate events by discussing the relationships occurring among oxidative/nitrosative/metabolic stress, inflammation and cancer.