Natural mechanisms protecting against cancer

Role of physical activity in tumor patients and possible underlying mechanisms

A growing knowledge regarding the influence of exercise on adverse physiologic outcomes associated with cancer and its treatment exists. Aside from its effects on psychological behavior, quality of life, and cancer-related fatigue, physical exercise can target physical and cardio-respiratory fitness, insulin regulation and metabolic syndrome, body weight and composition, and immune function in tumor patients. The increasing number of study results for different cancer types, which prove the positive influences of physical activity in cancer patients, changed the contradictory opinions which existed until the end of the last century. Although an increasing number of studies showing the positive effects of physical activity and more specifically of endurance and resistance training in cancer patients have been published, the underlying mechanisms are mostly unknown. Thus, we summarized the current knowledge of the effects of physical activity and specific training in different tumor entities with specific respect to the possible underlying mechanisms. Especially, the association between physical activity and (1) the improvement of fatigue and the role of free radicals in this process, (2) the counterbalance of tumor-induced cachexia, (3) the improvement of the immune system for supportive tumor treatment, and (4) the possible role of epigenetic modulation against tumor and tumor treatment-dependent adverse physiologic outcomes is focused.

Anti-ganglioside anti-idiotypic vaccination: more than molecular mimicry

Surgery, chemotherapy, and radiation therapy are standard modalities for cancer treatment, but the effectiveness of these treatments has reached a plateau. Thus, other strategies are being explored to combine with the current treatment paradigms in order to reach better clinical results. One of these approaches is the active immunotherapy based on the induction of anti-tumor responses by anti-idiotypic vaccination. This approach arose from Jerne’s idiotypic network theory, which postulates that B lymphocytes forms a functional network, with a role in the establishment of the immune repertoires, in the regulation of natural antibody production and even in the establishment of natural tolerance. Due to the large potential diversity of the immunoglobulin variable regions, the idiotypes repertoire can mimic the universe of self and foreign epitopes, even those of non-protein nature, like gangliosides. Gangliosides are sialic acid-containing glycolipids that have been considered attractive targets for cancer immunotherapy, based on the qualitative and quantitative changes they suffer during malignant transformation and due to their importance for tumor biology. Although any idiotype could be able to mimic any antigen, only those related to antigens involved in functions relevant for organism homeostasis, and that in consequence has been fixed by evolution, would be able not only to mimic, but also to activate the idiotypic cascades related with the nominal antigen. The present review updates the results, failures and hopes, obtained with ganglioside mimicking anti-idiotypic antibodies and presents evidences of the existence of a natural response against gangliosides, suggesting that these glycolipids could be idiotypically relevant antigens.

Immunoglobulin g from breast cancer patients regulates MCF-7 cells migration and MMP-9 activity by stimulating muscarinic acetylcholine receptors

PURPOSE

We have previously reported the expression of muscarinic acetylcholine receptors (mAChR) in human breast tumors. The activation of these receptors triggered tumor cell proliferation. Considering that invasion and metastasis is the major cause of death in cancer, we investigated the action of autoantibodies against mAChR derived from breast cancer patients in stage I (T1N0Mx-IgG) on MCF-7 cells migration and metalloproteinase-9 (MMP-9) activity. We also analyzed the participation of phospholipase C/nitric oxide synthase/protein kinase C pathway.

METHODS

Immunoglobulin G (IgG) was purified by chromatography in protein G-agarose from blood samples of breast cancer patients obtained under informed consent. Migration was assayed by an in vitro wound assay. MMP-9 activity was quantified by zymography.

RESULTS

T1N0Mx-IgG promoted tumor cell migration and increased MMP9 activity mimicking the action of the muscarinic agonist carbachol. This effect was reduced not only by the presence of atropine but also by 4-DAMP or tropicamide, antagonists for M(3) and M(4) mAChR subtypes respectively. The actions of T1N0Mx-IgG and carbachol on MCF-7 cells, involved the participation of phospholipase C/nitric oxide synthase/protein kinase C pathway.

CONCLUSIONS

IgG from breast cancer patients in stage I could be promoting tumor progression by regulating migration and MMP-9 activity in tumor cells via mAChR activation. The presence of these autoantibodies could be determining the prognosis of breast cancer in these patients.

Black rice bran as an ingredient in noodles: chemical and functional evaluation

This study examined the feasibility of using black rice bran (BRB) as an ingredient of noodles and evaluated the effect of BRB incorporation in noodles in terms of chemical and functional attributes. Noodles were prepared with BRB as an ingredient at different levels (2%, 5%, 10%, and 15%). Addition of BRB (5%, 10%, and 15%) significantly decreased the cohesiveness of noodles in texture evaluation. Noodles with different levels of BRB were functionally evaluated and content of polyphenolics, flavonoids, and anthocyanins were improved compared to the control. Additionally, antioxidant activity of BRB noodles was increased compared to the control. BRB can be an excellent ingredient to increase the nutritional value and antioxidant properties of noodles.

Safety and Tolerability of Ganoderma lucidum in Healthy Subjects: A Double-Blind Randomized Placebo-Controlled Trial

Ganoderma lucidum is a herbal medicine commonly used in oriental countries as a remedy for treating various medical conditions. In this controlled study, we evaluated the safety and tolerance of oral administration of Ganoderma lucidum in 16 human volunteers who received 2 grams of the extract or placebo twice daily for 10 consecutive days. During the study, information from subjective questionnaires were obtained, electrocardiograms, complete blood counts, blood chemistry analysis and urinalysis were performed. In addition, blood tests reflecting immunity were done. Our data showed that compared to placebo group, no adverse effects were observed after the extract intake. Although there were no obvious changes in CD4, CD8, and CD19 levels after the extract, CD56 cell count increased during the study and returned to baseline 10 days after the herbal intake. However, due to relatively high variability and small sample size, this CD56 increase did not achieve statistical significance, and remains to be re-evaluated in the future. It appears that an additional long-term safety and tolerance trial with herbal dose-escalating design is warranted.

Evidence of aberrant DNA damage response signalling but normal rates of DNA repair in dividing lymphoblasts from patients with schizophrenia

OBJECTIVES

Cancer incidence in schizophrenia is not increased commensurate with higher rates of risk exposures. Here we report an investigation of the DNA damage response, an anti-tumorigenic defence, in immortalised lymphoblasts from patients with schizophrenia.

METHODS

Unirradiated and irradiated (5Gy) lymphoblasts from schizophrenia patients (n = 28) and healthy controls (n = 28) were immunostained for the phosphorylated histone variant H2AX (γH2AX), an index of DNA double-strand breaks. Flow cytometry was used to assess cell cycle distribution and γH2AX immunofluorescence. Rate of DNA repair was quantified by determining the temporal change in γH2AX values following irradiation.

RESULTS

In unirradiated lymphoblasts, γH2AX levels were significantly increased in the schizophrenia group compared with controls (effect size = 0.86). This increase was most evident in patients with cognitive deficits. In irradiated lymphoblasts, peak radiation-induced γH2AX levels were significantly reduced in patients. No differences between patients and controls were found in the rate of DNA repair or in cell cycle distribution.

CONCLUSIONS

The significant differences in DNA damage response signalling observed involve modification of histone variant H2AX and thereby implicate regulatory processes determining chromatin structure in dividing lymphoblasts from patients with schizophrenia. The role that aberrant DNA damage response signalling plays in protecting patients from cancer is unclear.

Do dietary supplements have beneficial health effects in industrialized nations: what is the evidence?

BACKGROUND

Dietary supplements are regularly used by at least half of the American population, yet the health benefits of these agents are unclear.

OBJECTIVE

A systematic review to determine the benefits and risks of dietary supplements in Westernized societies.

DATA SOURCES

MEDLINE, Embase, Cochrane Register of Controlled Trials and citation review of relevant articles.

STUDY SELECTION

Randomized, placebo-controlled clinical trials in non-pregnant Westernized adults that evaluated clinical outcomes of nutritional supplements.

DATA EXTRACTION

Data were abstracted on study design, study size, study setting, patient population, dietary intervention and clinical outcomes. The outcome of each study was classified as non-beneficial, beneficial or harmful according to whether the end-point(s) of interest reached statistical significance.

DATA SYNTHESIS

Sixty-three studies met the criteria for our systematic review. No benefit was recorded in 45 studies, with 10 of these showing a trend towards harm and with two showing a trend towards benefit. Four studies reported harm with increased cancer deaths (n=2) and increased fractures (n=2). Two studies reported both a harmful as well as a beneficial outcome. A beneficial outcome was reported in 12 studies; 6 which studied vitamin D and three which investigated omega-3 fatty acids. While a benefit was reported in one study each which investigated Vitamin E, folic acid and Ginkgo biloba this benefit was not confirmed by larger and more adequately powered studies.

CONCLUSIONS

With the possible exceptions of Vitamin D and omega-3 fatty acids there is no data to support the widespread use of dietary supplements in Westernized populations; indeed, many of these supplements may be harmful.

Naturally occurring antibodies directed against carbohydrate tumor antigens

Healthy persons carry within their pool of circulating antibodies immunoglobulins preferentially of IgM isotype, which are directed against a variety of tumor-associated antigens. In closer scrutiny of their nature, some of these antibodies could be defined as naturally occurring antibodies due to the germline configuration of the variable immunoglobulin region. The majority of these immunoglobulins recognize carbohydrate antigens which can be classified as oncofetal antigens. Many of these IgM antibodies present in the peripheral blood circulation can bind to tumor cells and of these a minor portion are also able to destroy tumor cells by several mechanisms, as for instance complement-mediated cytolysis or apoptosis. It was postulated that anti-carbohydrate antibodies are part of an anti-tumor immune response, while their presence in the peripheral blood of healthy donors is still waiting for a plausible explanation. It may be that recognition of defined epitopes, including carbohydrate sequences, by naturally occurring antibodies constitutes the humoral arm of an anti-tumor immune response as part of the often postulated tumor surveillance. The cytotoxic capacity of these antibodies inspired several research groups and pharmaceutical companies to design novel strategies of immunoglobulin-based anti-tumor immunotherapy.

Hodgkin disease and the role of the immune system

Hodgkin disease (HD) is a malignancy of primarily B lymphocytes that has the unique ability to cause immunodeficiency, as well as provide immune evasion mechanisms to avoid self-destruction. In this review, the authors discuss Hodgkin disease, its association with Epstein-Barr virus (EBV), the immune deficiency caused by HD, and tumor immune evasion mechanisms. Specifically, the authors closely evaluate the roles of regulatory T cells in HD, cytotoxic T cells, cytokine and chemokine secretion, down-regulation of Fas ligand, and indoleamine 2,3-dioxygenase (IDO) secretion.

Physical activity and gynecologic cancer prevention

This chapter reviews the findings from epidemiologic studies of the associations of physical activity with gynecologic cancers, including those of the endometrium, ovaries, and cervix, and the biologic mechanisms mediating the associations. The epidemiologic evidence to date suggests that physical activity probably protects against endometrial cancer, with a risk reduction of about 20-30% for those with the highest levels of physical activity compared to those with the lowest levels, and that light to moderate physical activity including housework, gardening, or walking for transportation may reduce risk. The role of physical activity in ovarian cancer development remains uncertain, as findings from these studies have been inconsistent with about half the studies suggesting physical activity modestly decreases risk and about half the studies suggesting no association. A recent meta-analysis of studies examining recreational physical activity with ovarian cancer risk estimated a 20% reduced risk for the most active versus least active women. There is mounting evidence that sedentary behaviors such as sitting time probably increase risk of endometrial and ovarian cancers. Overall, there is insufficient evidence to draw a conclusion on a possible role of physical activity in the development of cervical cancer, although a modest influence on risk is possible through effects on sex steroid hormones and immune function. The biologic evidence provides strong support for a protective role of physical activity on cancer of the endometrium, and moderate support for cancer of the ovaries, as these cancers have a strong hormonal etiology. The more established biologic mechanisms that are supported by epidemiologic and experimental data involve endogenous sex hormone levels, insulin-mediated pathways, and maintenance of energy balance.In this chapter, we will discuss the evidence for an association of physical activity with gynecologic cancers including those of the endometrium, ovaries, and cervix. Cancers of the endometrium and ovaries have a strong hormonal etiology (Risch 1998; Kaaks et al. 2002; Lukanova and Kaaks 2005), and physical activity has been postulated as a potential modifiable risk factor for prevention of these cancers because it can influence circulating hormone levels, energy balance, and insulin-mediated pathways that are thought to be important mediators underlying the associations. Few studies have evaluated the association of physical activity with cervical cancer because the main causal factor is infection with certain types of human papillomavirus (HPV), although other hormonal and immune factors are also thought to play a role (Smith et al. 2003; Waggoner 2003). We review the findings from epidemiologic studies that have examined the associations of physical activity with gynecologic cancers, and the biologic mechanisms that might mediate the associations.

High incidence of tumors in diabetic thrombin activatable fibrinolysis inhibitor and apolipoprotein E double-deficient mice

BACKGROUND

Activation of the complement system has been implicated in tumor growth. The antifibrinolytic protein, activated thrombin-activatable fibrinolysis inhibitor (TAFIa), can modulate the activation of the complement system by inactivating the anaphylatoxins C3a and C5a. The apolipoprotein-E (ApoE) genotype has been associated with carcinogenesis.

OBJECTIVE

The aim of this study was to evaluate whether TAFIa can affect the development of cancer in the ApoE-deficient mouse model.

METHODS

TAFI and ApoE double-knockout mice were generated. A group of mice was treated with the diabetogenic and carcinogenic compound streptozotocin (stz). Mice treated with saline, single knockout mice and wild-type (wt) mice served as controls.

RESULTS

Six months after treatment with stz, mice were sacrificed. Hepatic tumors were found in male double-knockout mice treated with stz but none was found in control animals that were not treated with stz or in single knockout of ApoE or wt animals. There was no significant difference in coagulation system activation between the groups of mice. The plasma concentrations of C5a, factor D and transforming growth factor-β1 were increased in TAFI/ApoE double-deficient mice treated with stz compared with the mice of the same genotype treated with saline.

CONCLUSION

Apo-E deficiency alone was not associated with tumors but the lack of TAFI appears to make the mice permissive for tumor formation in ApoE mice.

Chalcones and dihydrochalcones augment TRAIL-mediated apoptosis in prostate cancer cells

Chalcones and dihydrochalcones exhibit chemopreventive and antitumor activity. TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is a natural endogenous anticancer agent. We examined the cytotoxic and apoptotic effect of chalcones and dihydrochalcones on TRAIL-mediated apoptosis in LNCaP prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was detected using annexin V-FITC by flow cytometry and fluorescence microscopy. The DeltaPsim was evaluated using DePsipher staining by fluorescence microscopy. Our study showed that two tested chalcones (chalcone and 2',6'dihydroxy-4'-methoxychalcone) and three dihydrochalcones (2',6'-dihydroxy-4'4-dimethoxydihydrochalcone, 2',6'-dihydroxy-4'-methoxydihydro- chalcone, and 2',4',6'-trihydroxydihydrochalcone, called phloretin) markedly augmented TRAIL-induced apoptosis and cytotoxicity in LNCaP cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer.

Activation of cytokine-producing and antitumor activities of natural killer cells and macrophages by engagement of Toll-like and NOD-like receptors

Macrophages and natural killer (NK) cells are important antitumor effectors by virtue of their ability to produce cytokines, chemokines and interferons (IFNs) and to mediate tumor cytotoxicity. Little is known about the impact of Toll-like receptor (TLR) and nucleotide binding and oligomerization domain (NOD)-like receptor (NLR) pathways on NK cell functions, and the role of TLRs and NLRs in macrophage activation is incompletely understood. In this study, we examined the capacities of expressed TLRs and NLRs to elicit cytokine production in human NK cells and THP1 macrophages, and to activate NK cytotoxicity against the squamous cell carcinoma of head and neck cell line Tu167 and erythroleukemia K562 cells. We found that NK cells express high levels of NOD2, NLRP3, TLR3, TLR7, and TLR9, while NOD1 was expressed at low levels. All tested NLR and TLR agonists potentiated NK cytotoxicity against Tu167 cells, whereas only poly (I:C) increased NK cytotoxicity against K562 cells. Poly (I:C) and Escherichia coli RNA markedly up-regulated TNF-α and IFN-γ expression in the NK92 cell line and human CD56(+)CD3(-) primary NK cells. High levels of NOD2, TLR7 and TLR9 proteins were observed in human THP1 cells, followed by TLR3, NOD1, and NLRP3. Stimulation of NLRP3 with E. coli RNA led to the highest induction of TNF-α, IL-6, IL-12p40, RANTES and IFN-β, whereas TLR7, TLR3, TLR9, NOD1 and NOD2 agonists had lower effects. Our data reveal involvement of TLRs and NLRs in potentiation of antitumor cytotoxicity and cytokine-producing activities of human NK cells and macrophages.

The expression and activity of cystathionine-γ-lyase and 3-mercaptopyruvate sulfurtransferase in human neoplastic cell lines

The expression and activity of cystathionine γ-lyase (CST) and 3-mercaptopyruvate sulfurtransferase (MPST) were investigated in the human neoplastic cells lines: astrocytoma U373, neuroblastoma SH-SY5Y, melanoma A375, and melanoma WM35. Gene expression analysis demonstrated that the investigated neoplastic cells showed the expression of MPST and what is particularly interesting, the expression of CST. The presence of CST in these cells was confirmed using RT-PCR and western blot analysis. However, in U373 cells, a very low activity of CST was detected. In all the investigated cell lines, the activity of MPST was higher than that of CST, which suggests that in these cells, the main pathway of sulfane sulfur formation is the MPST-catalyzed reaction. RP-HPLC analysis showed a large disparity between the level of cystathionine and GSH in the investigated neoplastic cells. In SH-SY5Y cells, the low level of GSH and low GSH/GSSG ratio corresponded with the highest CST activity. Further investigations could aim at verifying whether the stimulation of CST, at the level of protein or gene expression, could change the proliferation of neoplastic cells.

Antigen-specific immunity and cross-priming by epithelial ovarian carcinoma-induced CD11b(+)Gr-1(+) cells

Both innate and adaptive immune systems are considered important for cancer prevention, immunosurveillance, and control of cancer progression. It is known that, although both systems initially eliminate emerging tumor cells efficiently, tumors eventually escape immune attack by a variety of mechanisms, including differentiation and recruitment of immunosuppressive CD11b(+)Gr-1(+) myeloid suppressor cells into the tumor microenvironment. However, we show that CD11b(+)Gr-1(+) cells found in ascites of epithelial ovarian cancer-bearing mice at advanced stages of disease are immunostimulatory rather than being immunosuppressive. These cells consist of a homogenous population of cells that morphologically resemble neutrophils. Moreover, like dendritic cells, immunostimulatory CD11b(+)Gr-1(+) cells can strongly cross-prime, augmenting the proliferation of functional CTLs via signaling through the expression of costimulatory molecule CD80. Adoptive transfer of these immunostimulatory CD11b(+)Gr-1(+) cells from ascites of ovarian cancer-bearing mice results in the significant regression of s.c. tumors even without being pulsed with exogenous tumor Ag prior to adoptive transfer. We now show for the first time that adaptive immune responses against cancer can be augmented by these cancer-induced granulocyte-like immunostimulatory myeloid (CD11b(+)Gr-1(+)) cells, thereby mediating highly effective antitumor immunity in an adoptive transfer model of immunity.

Oxidative and nitrosative stress in the metastatic microenvironment

Metastases that are resistant to conventional therapies are the main cause of most cancer-related deaths in humans. Tumor cell heterogeneity, which associates with genomic and phenotypic instability, represents a major problem for cancer therapy. Additional factors, such as the attack of immune cells or organ-specific microenvironments, also influence metastatic cell behavior and the response to therapy. Interaction of cancer and endothelial cells in capillary beds, involving mechanical contact and transient adhesion, is a critical step in the initiation of metastasis. This interaction initiates a cascade of activation pathways that involves cytokines, growth factors, bioactive lipids and reactive oxygen and nitrogen species (ROS and RNS) produced by either the cancer cell or the endothelium. Vascular endothelium-derived NO and H₂O₂ are cytotoxic for the cancer cells, but also help to identify some critical molecular targets that appear essential for survival of invasive metastatic cell subsets. Surviving cancer cells that extravasate and start colonization of an organ or tissue can still be attacked by macrophages and be influenced by specific intraorgan microenvironment conditions. At all steps; from the primary tumor until colonization of a distant organ; metastatic cells undergo a dynamic process of constant adaptations that may lead to the survival of highly resistant malignant cell subsets. In this sequence of molecular events both ROS and RNS play key roles.

Immunoglobulin G from breast cancer patients in stage I stimulates muscarinic acetylcholine receptors in MCF7 cells and induces proliferation. Participation of nitric oxide synthase-derived nitric oxide

INTRODUCTION

Muscarinic acetylcholine receptors (mAChR) belong to the G-protein-coupled receptor family and are extensively expressed in most cells in mammals. We had reported the expression of mAChR in murine and human breast tumors.

METHODS

The presence of antibodies in the sera of patients with different tumors directed against self-proteins has been recently described. In this work, we investigated the presence of autoantibodies against mAChR in the sera of breast cancer patients in stage I (T1N0Mx-IgG). IgG purification was performed by affinity chromatography in protein G-agarose. We also studied the ability of these antibodies to modulate the proliferation of MCF-7 breast tumor cells by the MTS colorimetric assay. The ability of T1N0Mx-IgG to stimulate muscarinic signaling pathway via nitric oxide synthase was tested by Griess reaction.

RESULTS

We demonstrated M(3) and M(4) receptors expression in MCF-7 cells. T1N0Mx-IgG promotes cell proliferation, mimicking the action of the muscarinic agonist carbachol. This effect was preferentially due to M(3) receptor activation in tumor cells via phospholipase C-induced nitric oxide liberation by calcium-dependent nitric oxide synthases. IgG from control patients was unable to produce this effect.

DISCUSSION

IgG from patients with breast cancer in early stages could be promoting tumor progression by muscarinic activation, and its presence could be determining the prognosis of this illness.

Physical activity and lung cancer prevention

Since lung cancer is among the cancers with the highest incidence and has the highest mortality rate of cancer worldwide, the means of reducing its impact are urgently needed. Emerging evidence shows that physical activity plays an etiological role in lung cancer risk reduction. The majority of studies support the fact that total and recreational physical activity reduces lung cancer risk by 20-30% for women and 20-50% for men, and there is evidence of a dose-response effect. The biological mechanisms operating between physical activity and lung cancer are likely complex and influenced by many factors including inherited or acquired susceptibility genes, gender, smoking, and other environmental factors. Several plausible biological factors and mechanisms have been hypothesized linking physical activity to reduced lung cancer risk including: improved pulmonary function, reduced concentrations of carcinogenic agents in the lungs, enhanced immune function, reduced inflammation, enhanced DNA repair capacity, changes in growth factor levels and possible gene-physical activity interactions. Future research should target the possible subgroup effects and the biologic mechanisms that may be involved.

Chalcones enhance TRAIL-induced apoptosis in prostate cancer cells

Chalcones exhibit chemopreventive and antitumor effects. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a naturally occurring anticancer agent that induces apoptosis in cancer cells and is not toxic to normal cells. We examined the cytotoxic and apoptotic effect of five chalcones in combination with TRAIL on prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was determined using flow cytometry with annexin V-FITC. Our study showed that all five tested chalcones: chalcone, licochalcone-A, isobavachalcone, xanthohumol, butein markedly augmented TRAIL-mediated apoptosis and cytotoxicity in prostate cancer cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer.

Clinicopathological characteristics of tumor-infiltrating lymphocytes in colorectal cancer

AIM: To investigate the clinicopathological characteristics and immunohistochemical features of tumor-infiltrating lymphocyte (TIL) in colorectal cancer, and analyze the correlations between the presence of massive TIL and various pathological parameters in colorectal cancer.

METHODS: The histopathological features of tumor-infiltrating lymphocytes in 370 cases of colorectal cancer were detected by light microscopy and immunohistochemistry. The correlations between the presence of massive TIL and various clinicopathological parameters in colorectal cancer were then analyzed.

RESULTS: Of 370 cases of colorectal cancer detected, 303 (81.9%) showed mild infiltration of scattered lymphocytes, and 67 (18.1%) showed massive lymphocyte infiltration. The majority of lymphocytes were infiltrated into both the stromal and epithelial components of carcinoma. TIL were often distributed around cancer tissue, and separated cancer tissue from normal tissue. Immunohistochemical staining showed that TIL were mainly composed of CD3+ T cells, CD20⁺ CD79α+ B cells, and CD56+ natural killer cells. T-cell-restricted intracellular antigen-1 (TIA-1) was strongly expressed in TIL. Massive lymphocyte infiltration was correlated with tumor differentiation, invasive depth and lymph node metastasis in colorectal cancer (χ² = 4.954, 11.240, 12.768; P = 0.026, 0.001, 0.000, respectively).

CONCLUSION: The clinicopathological characteristics of tumor-infiltrating lymphocytes in colorectal cancer vary significantly. The presence of massive tumor-infiltrating lymphocytes is a positive prognostic factor for colorectal cancer.

Dietary patterns, risk and prognosis of breast cancer

Survival in women diagnosed with early-stage, invasive breast cancer has improved dramatically in the past 10–15 years. This is largely due to the use of pharmacological therapies targeting a reduction in estrogen action and exposure. Women diagnosed with breast cancer often alter their eating behavior towards healthier food choices in an attempt to improve their survival and their overall health and well being. Mounting interest in the role of diet to modify breast cancer survival and/or comorbidity and mortality has led researchers to evaluate the effects of differential dietary patterns on this disease. Current findings suggest a possible, but inconsistent, benefit of a prudent, vegetable-rich, low-fat/high-vegetable eating pattern on disease-free survival, but the results to date are limited by strong treatment effectiveness and low overall recurrence rates. It is more likely this prudent eating pattern will improve non-breast cancer mortality (e.g., cardiovascular disease) compared with a Western dietary pattern. Efforts to educate women diagnosed with breast cancer to consume a diet lower in total and saturated fat, higher in vegetables and fiber, and which results in mild to modest weight loss among overweight/obese women is sensible in light of the high survivability of breast cancer and need to direct attention to comorbidities that likely increase as a consequence of treatment and treatment-related weight gain and sedentary behavior. Additional research is needed to address the importance of diet in the breast cancer patient, particularly in relation to the effect of select dietary patterns on factors that influence individual recurrence risk (e.g., hormone levels, drug metabolism and oxidative stress), as well as factors that influence non-breast cancer morbidity risk and causes of death in the survivor population.

Degranulation Patterns of Eosinophils in Advanced Gastric Carcinoma: An Electron Microscopic Study

Recruitment and activation of eosinophils have been studied intensely in asthma and other allergic diseases. Less is known about the infiltration and degranulation patterns of eosinophils in the tumor stroma. Seven cases of advanced gastric carcinomas were found to be massively infiltrated by eosinophils and studied by light and electron microscopy. Gastric carcinomas, despite having similar numbers of tissue eosinophils, exhibited markedly different degranulation patterns. In 2 cases, resting nondegranulating eosinophils were found. Piecemeal degranulation was the predominant mode of secretion from eosinophils localized within the tumor stroma in 4 cases. Eosinophil exocytosis and cytolysis were rarely observed. In 1 case, crystals morphologically similar to Charcot-Leyden crystals were observed at the extracellular level as well as in phagosomes of tissue macrophages, confirming active sequestrations of eosinophil Charcot-Leyden protein by macrophages in vivo. In the same case, eosinophils showed characteristic features of early and late apoptotic changes, such as condensed chromatin, focal dilatation of nuclear envelope, and preserved plasma membrane. Morphological association between apoptotic eosinophils and deposition of granules in the tumor stroma was found. Extracellular deposition of intact granules from apoptotic eosinophils was distinct from eosinophilic (necrotic) cytolysis, and has reported previously in experimental studies in vitro. To the knowledge of the authors, this case represents the first report of late apoptotic eosinophils that release their granules within the tumor stroma in a human gastric carcinoma.

Long-term use of beta-carotene, retinol, lycopene, and lutein supplements and lung cancer risk: results from the VITamins And Lifestyle (VITAL) study

High-dose beta-carotene supplementation in high-risk persons has been linked to increased lung cancer risk in clinical trials; whether effects are similar in the general population is unclear. The authors examined associations of supplemental beta-carotene, retinol, vitamin A, lutein, and lycopene with lung cancer risk among participants, aged 50-76 years, in the VITamins And Lifestyle (VITAL) cohort Study in Washington State. In 2000-2002, eligible persons (n = 77,126) completed a 24-page baseline questionnaire, including detailed questions about supplement use (duration, frequency, dose) during the previous 10 years from multivitamins and individual supplements/mixtures. Incident lung cancers (n = 521) through December 2005 were identified by linkage to the Surveillance, Epidemiology, and End Results cancer registry. Longer duration of use of individual beta-carotene, retinol, and lutein supplements (but not total 10-year average dose) was associated with statistically significantly elevated risk of total lung cancer and histologic cell types; for example, hazard ratio = 2.02, 95% confidence interval: 1.28, 3.17 for individual supplemental lutein with total lung cancer and hazard ratio = 3.22, 95% confidence interval: 1.29, 8.07 for individual beta-carotene with small-cell lung cancer for >4 years versus no use. There was little evidence for effect modification by gender or smoking status. Long-term use of individual beta-carotene, retinol, and lutein supplements should not be recommended for lung cancer prevention, particularly among smokers.

Aging and neutrophils: there is still much to do

Human neutrophils are activated by a wide array of compounds through their receptors. This elicits their classical functions, such as chemotaxis, phagocytosis, and the production of reactive oxygen species (ROS). Upon stimulation, neutrophils also produce lipid and immune mediators and can present antigen through the major histocompatibility complex I (MHC-I). The age-related impairment of the classical functions of neutrophils is well described, but experimental evidence showing alterations in the production of mediators and antigen presentation with aging are lacking. This review highlights the role of neutrophils in age-related pathologies such as Alzheimer's disease, atherosclerosis, cancer, and autoimmune diseases. Furthermore, we discuss how aging potentially affects the production and release of mediators by human neutrophils in ways that may contribute to the development of these pathologies.

Glutathione in Cancer Biology and Therapy

The glutathione (GSH) content of cancer cells is particularly relevant in regulating mutagenic mechanisms, DNA synthesis, growth, and multidrug and radiation resistance. In malignant tumors, as compared with normal tissues, that resistance associates in most cases with higher GSH levels within these cancer cells. Thus, approaches to cancer treatment based on modulation of GSH should control possible growth-associated changes in GSH content and synthesis in these cells. Despite the potential benefits for cancer therapy of a selective GSH-depleting strategy, such a methodology has remained elusive up to now. Metastatic spread, not primary tumor burden, is the leading cause of cancer death. For patient prognosis to improve, new systemic therapies capable of effectively inhibiting the outgrowth of seeded tumor cells are needed. Interaction of metastatic cells with the vascular endothelium activates local release of proinflammatory cytokines, which act as signals promoting cancer cell adhesion, extravasation, and proliferation. Recent work shows that a high percentage of metastatic cells with high GSH levels survive the combined nitrosative and oxidative stresses elicited by the vascular endothelium and possibly by macrophages and granulocytes. ?-Glutamyl transpeptidase overexpression and an inter-organ flow of GSH (where the liver plays a central role), by increasing cysteine availability for tumor GSH synthesis, function in combination as a metastatic-growth promoting mechanism. The present review focuses on an analysis of links among GSH, adaptive responses to stress, molecular mechanisms of invasive cancer cell survival and death, and sensitization of metastatic cells to therapy. Experimental evidence shows that acceleration of GSH efflux facilitates selective GSH depletion in metastatic cells.

Immune, endocrine, and behavioral precursors to breast cancer recurrence: a case-control analysis

BACKGROUND

A period of tumor growth precedes the clinical detection of breast cancer recurrence. We explore immune, endocrine, and behavioral parameters during this period.

METHODS

We conducted a phase III clinical trial in which women with surgically treated stage II/III breast cancer (N = 227) were randomized to receive a psychological intervention or assessment-only and then regularly assessed for 10 years. Patients who recurred (R, n = 48) were matched with patients remaining disease-free (DF, n = 48) on demographic and prognostic characteristics, treatment, and duration of disease-free follow-up. Data at three assessment points, occurring, on average, 17, 11, and 4 months before the recurrence was detected clinically, with equivalent time points for the disease-free group, were examined. Mixed-effects models tested for group differences in immune cell counts and function as well as endocrine and behavioral parameters.

RESULTS

In the 17 months prior to recurrence detection, patients exhibited higher white blood cell count, neutrophil, lymphocyte, and natural killer cell counts, relative to DF patients. R patients also showed higher cortisol, worse physical functioning, fatigue, and quality of life. Follow-up analyses showed patients with local recurrences to differ from those with distant recurrence, with the former exhibiting elevated natural killer cell cytotoxicity, lymphocyte proliferative response, fatigue, pain, and emotional distress (depression, anxiety), and the latter exhibiting higher neutrophil, lymphocyte, and natural killer cell counts.

CONCLUSION

Patients who would recur showed reliable biobehavioral alterations more than a year prior to their diagnosis. This novel observation may contribute to our understanding of the disease relapse processes.

Therapeutic Actions of Melatonin in Cancer: Possible Mechanisms

Melatonin is a phylogenetically well-preserved molecule with diverse physiological functions. In addition to its well-known regulatory control of the sleep/wake cycle, as well as circadian rhythms generally, melatonin is involved in immunomodulation, hematopoiesis, and antioxidative processes. Recent human and animal studies have now shown that melatonin also has important oncostatic properties. Both at physiological and pharmacological doses melatonin exerts growth inhibitory effects on breast cancer cell lines. In hepatomas, through its activation of MT 1 and MT2 receptors, melatonin inhibits linoleic acid uptake, thereby preventing the formation of the mitogenic metabolite 1,3-hydroxyoctadecadienoic acid. In animal model studies, melatonin has been shown to have preventative action against nitrosodiethylamine (NDEA)-induced liver cancer. Melatonin also inhibits the growth of prostate tumors via activation of MT1 receptors thereby inducing translocation of the androgen receptor to the cytoplasm and inhibition of the effect of endogenous androgens. There is abundant evidence indicating that melatonin is involved in preventing tumor initiation, promotion, and progression. The anticarcinogenic effect of melatonin on neoplastic cells relies on its antioxidant, immunostimulating, and apoptotic properties. Melatonin's oncostatic actions include the direct augmentation of natural killer (NK) cell activity, which increases immunosurveillance, as well as the stimulation of cytokine production, for example, of interleukin (IL)-2, IL-6, IL-12, and interferon (IFN)-γ. In addition to its direct oncostatic action, melatonin protects hematopoietic precursors from the toxic effect of anticancer chemotherapeutic drugs. Melatonin secretion is impaired in patients suffering from breast cancer, endometrial cancer, or colorectal cancer. The increased incidence of breast cancer and colorectal cancer seen in nurses and other night shift workers suggests a possible link between diminished secretion of melatonin and increased exposure to light during nighttime. The physiological surge of melatonin at night is thus considered a “natural restraint” on tumor initiation, promotion, and progression.

Innate immune stimulation of exo-polymers prepared from Cordyceps sinensis by submerged culture

After we prepared exo-polymers (EPS) from Cordyceps sinensis by submerged culture, prophylactic intravenous administration (i.v.) of EPS significantly inhibited metastasis in experimental lung metastasis of colon 26-M3.1 carcinoma. Cytotoxicity against Yac-1 tumor cells of natural killer (NK) cell, which was prepared by i.v. of EPS (100 mug/mouse), significantly augmented 2 days after EPS treatment. When NK cells were depleted by rabbit anti-asialo GM1 serum, even the EPS group totally abolished the inhibitory effect on lung metastasis of colon 26-M3.1 cells. EPS can stimulate innate immune system to inhibit tumor metastasis, and its anti-tumor metastasis is associated with macrophage and NK cell activation.

Mechanisms linking physical activity with cancer

About 25% of cancer cases globally are due to excess weight and a sedentary lifestyle. Physical activity may decrease risk for various cancers by several mechanisms, including decreasing sex hormones, metabolic hormones and inflammation, and improving immune function. The level of physical activity might also be associated with prognosis among individuals with cancer. Randomized clinical trials have shown that physical activity interventions can change biomarkers of cancer risk. Observational studies can also provide useful information on mechanisms that might link physical activity to cancer.

Propolis and the immune system: a review

Propolis has been used empirically for centuries and it was always mentioned as an immunomodulatory agent. In recent years, in vitro and in vivo assays provided new information concerning its mechanisms of action, thus a review dealing with propolis and the immune system became imperative. This review compiles data from our laboratory as well as from other researchers, focusing on its chemical composition and botanical sources, the seasonal effect on its composition and biological properties, its immunomodulatory and antitumor properties, considering its effects on antibody production and on different cells of the immune system, involving the innate and adaptive immune response. In vitro and in vivo assays demonstrated the modulatory action of propolis on murine peritoneal macrophages, increasing their microbicidal activity. Its stimulant action on the lytic activity of natural killer cells against tumor cells, and on antibody production was demonstrated. Propolis inhibitory effects on lymphoproliferation may be associated to its anti-inflammatory property. In immunological assays, the best results were observed when propolis was administered over a short-term to animals. Propolis antitumor property and its anticarcinogenic and antimutagenic potential are discussed. Since humans have used propolis for different purposes and propolis-containing products have been marketed, the knowledge of its properties with scientific basis is not only of academic interest but also of those who use propolis as well. This review opens a new perspective on the investigation of propolis biological properties, mainly with respect to the immune system.

Low Body Mass Index in Kidney Transplant Recipients: Risk or Advantage for Long-Term Graft Function?

OBJECTIVES

Nutritional status is known to be a marker of overall health status and a strong predictor of patient survival in several diseases. Whereas obesity is suspected to have a negative influence on general renal transplantation outcomes, the relationship between impaired nutritional status and long-term kidney graft survival is not yet clear.

METHODS

We retrospectively analyzed graft survival with a follow-up time of 5 to 12.5 years among 224 kidney transplantations. A Cox proportional hazards model was applied to estimate risk factors for loss of graft function.

RESULTS

The Cox model initially showed no significant influence of the body mass index (BMI) at 1 year after transplantation on the risk of transplant failure (relative risk 0.97 per BMI unit, P = .34). When the patients were divided into two groups according to BMI, a clear disadvantage was shown in terms of long-term graft survival for the groups with a low BMI. The risk of loss of transplant function increased by a factor of 1.85 (relative risk) if the BMI 1 year after kidney transplantation was less than 23 (P = .035).

CONCLUSIONS

These findings suggested impaired long-term kidney graft survival among patients with reduced nutritional status. This result is assumed to reflect improved immune function due to reduced nutrient availability, thus leading to reinforcement of chronic rejection processes. This assumption is consistent with the already known immunomodulatory effect of caloric restriction to mitigate T-cell activation.

Autoimmunity, spontaneous tumourigenesis, and IL-15 insufficiency in mice with a targeted disruption of the tumour suppressor gene Fus1

The Fus1 gene resides in the critical 3p21.3 human chromosomal region deleted in lung and breast cancers. Recently, the tumour suppressor properties of Fus1 were confirmed experimentally by intra-tumoural administration of Fus1 that suppressed experimental lung metastasis in mice. We generated Fus1-deficient mice that were viable, fertile, and demonstrated a complex immunological phenotype. Animals with a disrupted Fus1 gene developed signs of autoimmune disease, such as vasculitis, glomerulonephritis, anaemia, circulating autoantibodies, and showed an increased frequency of spontaneous vascular tumours. Preliminary analysis of immune cell populations revealed a consistent defect in NK cell maturation in Fus1 null mice that correlated with changes in the expression of IL-15. Injection of IL-15 into Fus1 knockout mice completely rescued the NK cell maturation defect. Based on these results, we propose the hypothesis that Fus1 deficiency affects NK cell maturation through the reduction of IL-15 production but does not directly alter their developmental capacity. Since acquired immunity was not affected in Fus1-deficient animals, we suggest a relationship between the Fus1 protein and the regulation of innate immunity via IL-15 production. The increased frequency of spontaneous cancers and the development of an autoimmune syndrome in Fus1 null mice imply that these mice could serve as a model for studying molecular mechanisms of anti-tumour immunity and autoimmunity.

Down-Regulation of Human Complement Factor H Sensitizes Non-Small Cell Lung Cancer Cells to Complement Attack and Reduces In Vivo Tumor Growth

Malignant cells are often resistant to complement activation through the enhanced expression of complement inhibitors. In this work, we examined the protective role of factor H, CD46, CD55, and CD59 in two non-small cell lung cancer cell lines, H1264 and A549, upon activation of the classical pathway of complement. Complement was activated with polyclonal Abs raised against each cell line. After blocking factor H activity with a neutralizing Ab, C3 deposition and C5a release were more efficient. Besides, a combined inhibition of factor H and CD59 significantly increased complement-mediated lysis. CD46 and CD55 did not show any effect in the control of complement activation. Factor H expression was knockdown on A549 cells using small interfering RNA. In vivo growth of factor H-deficient cells in athymic mice was significantly reduced. C3 immunocytochemistry on explanted xenografts showed an enhanced activation of complement in these cells. Besides, when mice were depleted of complement with cobra venom factor, growth was recovered, providing further evidence that complement was important in the reduction of in vivo growth. In conclusion, we show that expression of the complement inhibitor factor H by lung cancer cells can prevent complement activation and improve tumor development in vivo. This may have important consequences in the efficiency of complement-mediated immunotherapies.

Reactive oxygen species and antioxidant mechanisms in human tissues and their relation to malignancies

Reactive oxygen species (ROS) are formed in mammalian cells as a consequence of aerobic respiration. Despite multiple conserved redox modulating systems, a given proportion of ROS continuously escape from the mitochondrial respiratory chain, being sufficiently potent to damage cells in various ways, including numerous carcinogenic DNA mutations. Oxidative stress resulting from an imbalanced ratio between ROS production and detoxification may also disturb physiological signal transduction, lead to chain reactions in lipid layers, and damage DNA repair enzymes. The significance of ROS and antioxidant systems in carcinogenesis is still complicated and in many ways contradictory. Enhanced antioxidant mechanisms in tumor cells in vivo have been implicated in chemoresistance and lead to poor prognosis, whereas most in vitro studies have reported tumor-suppressing properties of antioxidant enzymes. The present review aims to clarify the significance of oxidative stress and the role of cell redox state modulating systems in human malignancies in light of the current literature.

Roles of the innate immune system in mammary gland remodeling during involution

Mammary gland involution is a period of intensive tissue remodeling. Over the course of a relatively brief period, a large proportion of the mammary gland epithelium undergoes programmed cell death and is removed by phagocytes. In addition, the gland is cleared of residual milk fat globules as well as milk and adipocytes become the predominant cell type. The role of the immune system in this process has not been clearly defined. Professional phagocytes derived from the immune system can participate in the clearance of apoptotic and autophagic cells, the removal of residual milk components, and the prevention of mastitis during mammary gland involution. However, many of these functions can also be performed by non-professional phagocytes (e.g. mammary epithelial cells). This review will discuss the evidence that supports a role for innate immune cells in mammary gland remodeling during involution.

Individual trajectories in stress covary with immunity during recovery from cancer diagnosis and treatments

Research connects stressful events with altered immune regulation, but the role of subjective stress is uncertain. Using a longitudinal design, we provide a statistically powerful test of the relationship between subjective stress (perceived stress, emotional distress) and immunity (T cell blastogenesis, natural killer cell cytotoxicity, [NKCC]) as individuals adjust to a severe stressor, a cancer diagnosis and its treatments. Women with regional breast cancer (N=113) were assessed at diagnosis/surgery and reassessed 4, 8, 12, and 18 months later. Latent growth curve analysis tested two hypotheses: (1) initial levels of subjective stress will correlate inversely with initial levels of immunity, and (2) rate of change in subjective stress will correlate inversely with rate of change in immunity. As predicted by Hypothesis 1, participants with high initial subjective stress showed poor initial blastogenesis. As predicted by Hypothesis 2, participants exhibiting an early, rapid decline in subjective stress also showed rapid improvement in NKCC. Follow-up analyses revealed perceived stress to be strongly related to immune function, while emotional distress was not. This is the first study to investigate trajectories in stress and immunity during recovery from a major stressor. Results imply that NK and T cells are sensitive to different aspects of the stress response. While T cell blastogenesis correlated with initial (peak) subjective stress, NKCC correlated with change (improvement) in subjective stress. These data highlight the importance of subjective stress, particularly stress appraisals, in the immune response to a major stressor.

Exercise and biomarkers for cancer prevention studies

The International Agency for Research on Cancer estimates that 25% of cancer cases worldwide are caused by overweight or obesity and a sedentary lifestyle. These lifestyle patterns may increase cancer risk by several mechanisms including increased estrogens and testosterone, hyperinsulinemia and insulin resistance, increased inflammation, and depressed immune function. Several randomized clinical trials have shown that physical activity and diet interventions can change biomarkers of cancer risk. In a controlled physical activity trial, we found decreases in serum estrogen, testosterone, and insulin in overweight, sedentary postmenopausal women with a 1-y exercise program consisting of moderate-intensity aerobic exercise, 45 min/d, 5 d/wk. In another controlled trial in middle-aged to older persons, we found that a 1-y exercise intervention of 60 min/d, 6 d/wk, reduced colon crypt cell proliferation in men who adhered closely to the program. Only 1 trial, the Women's Health Initiative Dietary Modification Trial, has published results of a dietary intervention on breast cancer incidence and reported a statistically nonsignificant 9% reduction in invasive breast cancer incidence in postmenopausal women following a low-fat dietary pattern for 8-12 y. Other trials under way are testing effects of weight loss, physical activity, and dietary patterns on other cancer biomarkers. The NCI-funded Transdisciplinary Research on Energetics and Cancer centers are exploring novel research into mechanisms linking energy balance with cancer risk and prevention. The worldwide trends toward increasing overweight and obesity and decreasing physical activity may lead to an increased incidence of several cancers unless other means of risk reduction counteract these effects. Thus, adoption of lifestyle changes by individuals and populations may have a large impact on the future incidence of cancer.

Clinical trials of vitamin and mineral supplements for cancer prevention

Approximately 20-30% of Americans consume multivitamin supplements daily, indicating high public interest in the prevention of cancer and other chronic diseases through a nutrition-based approach. Although several bioactive food components, including vitamins and minerals, have been investigated for their ability to affect cancer risk, few large, randomized, placebo-controlled clinical trials of multivitamins with cancer as the primary endpoint have been performed. The results of most large-scale trials of multivitamin supplements (combinations of > or = 2 vitamins and minerals) to prevent cancer have been mixed. The Linxian General Population and Dysplasia trials found a decreased risk of cancer, particularly stomach cancer, for participants taking a multivitamin supplement, but this was in a borderline-deficient population in China. Two trials, the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study and the beta-Carotene and Retinol Efficacy Trial, found an increased risk of lung cancer among male cigarette smokers or asbestos-exposed persons taking beta-carotene-a surprising result, considering that most epidemiologic studies have suggested that consumption of fruit and vegetables appears to lower cancer risk. To clarify the effects of multivitamin supplements, several large randomized clinical trials are underway, including the Physicians' Health Study II, the Selenium and Vitamin E Cancer Prevention Trial, and a European study, Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI. MAX). Because epidemiologic studies generally evaluate foods rather than specific bioactive food components, a systematic approach to determining how combinations of vitamins and minerals may interact to ameliorate cancer risk is necessary to further our understanding of the potential benefits and risks of supplement use.

Importance of the trans-sulfuration pathway in cancer prevention and promotion

The trans-sulfuration pathway is a biochemical mechanism that links methionine metabolism to the biosynthesis of cellular redox-controlling molecules, like cysteine, glutathione, and taurine. While there is some knowledge about the metabolic intermediates and enzymes that participate in trans-sulfuration, little is known about the physiological importance of this mechanism. Deficiencies within the trans-sulfuration pathway induces (i) the generation of reactive species of oxygen (ROS) and halogens (RHS), (ii) homocyst(e)ine accumulation, and (iii) the synthesis of proinflammatory molecules by macrophages, and contribute to humans pathologies like atherosclerosis and tumor development. In this review we outline the role of this biochemical pathway in tumor development and analyze current findings on the role of trans-sulfuration in mammalian physiology. The potential relationship between chronic inflammation, and tumor and atherosclerotic development are discussed.

Cancer as an evolutionary and ecological process

Neoplasms are microcosms of evolution. Within a neoplasm, a mosaic of mutant cells compete for space and resources, evade predation by the immune system and can even cooperate to disperse and colonize new organs. The evolution of neoplastic cells explains both why we get cancer and why it has been so difficult to cure. The tools of evolutionary biology and ecology are providing new insights into neoplastic progression and the clinical control of cancer.

Gene expression differences in normal esophageal mucosa associated with regression and progression of mild and moderate squamous dysplasia in a high-risk Chinese population

A randomized, double-blinded, placebo-controlled 2 x 2 factorial chemoprevention trial was conducted in Linxian, China to assess the effects of selenomethionine and celecoxib on the natural history of esophageal squamous dysplasia. Results from this study indicated that asymptomatic adults with mild dysplasia were more likely to show an improvement when treated with selenomethionine compared with placebo (P = 0.02). Prompted by this finding, we examined the molecular profiles associated with regression and progression of dysplastic lesions in normal mucosa from 29 individuals, a subset of the Linxian cohort, using the Affymetrix U133A chip. Twenty differentially expressed genes were associated with regression and 129 were associated with progression when we compared the change in gene expression over time. Genes associated with immune response (n = 15), cell cycle (n = 15), metabolism (n = 15), calcium transport or calcium ion activity (n = 10), regulation of transcription (n = 9), signal transduction (n = 7), cytoskeleton and microtubules (n = 5), nucleotide processing and biosynthesis (n = 4), G-coupled signaling (n = 4), and apoptosis (n = 3) were present in the list of 149 genes. Using the Expression Analysis Systematic Explorer pathway analysis program, only the immune response pathway was significantly overrepresented among these 149 genes. Individuals whose lesions regressed seemed to have higher expression of genes associated with immune stimulation, such as antigen presentation, survival of T cells, and T-cell activation (HLA-DRA, HLA-DPA1, HLA-DBQ1, CD58, and FCER1A). In contrast, individuals whose lesions progressed had higher expression of genes involved in immune suppression and inflammation (CNR2, NFATC4, NFRKB, MBP, INHBB, CMKLR1, CRP, ORMS, SERPINA7, and SERPINA1). These data suggest that local and systemic immune responses may influence the natural history of esophageal squamous dysplasia.

Kinase domain insert containing receptor promoter controlled suicide gene system selectively kills human umbilical vein endothelial cells

AIM: To study the selective killing of human umbilical vein endothelial cells (HUVECs) by a double suicide gene under the regulation of a kinase domain insert containing receptor (KDR) promoter and mediated by an adenoviral gene vector.

METHODS: Human KDR promoter was cloned by polymerase chain reaction (PCR), and two recombinant adenoviral plasmids pAdKDR-CdglyTK, pAdCMV-CDglyTK were constructed according to a two-step transformation protocol. These two newly constructed plasmids were then transfected into 293 packaging cells to grow adenovirus, which were further multiplied and purified. HUVECs and LoVo cells were infected with either of the two resultant recombinant adenoviruses (AdKDR-CDglyTK and AdCMV-CDglyTK) respectively, and the infection rates were estimated by detection of green fluorescent protein (GFP) expression. Infected cells were cultured in culture media containing different concentrations of 5-fluorocytosine (5-FC) and ganciclovir (GCV), and the killing effects were measured.

RESULTS: The two recombinant adenoviral plasmids pAdKDR-CdglyTK, pAdCMV-CDglyTK were successfully constructed and transfected into 293 cells. The resultant recombinant adenoviruses infected cells caused similar infection rates; and the infected cells exhibited different sensitivity to the prodrugs: HUVECs infected with AdCMV-CDglyTK and LoVo cells infected with AdCMV-CDglyTK were highly sensitive to the prodrugs, and HUVECs infected with AdKDR-CDglyTK were similarly sensitive but significantly more sensitive than the LoVo cells infected with AdKDR-CdglyTK (P < 0.001).

CONCLUSION: Selective killing of HUVECs may be achieved by gene transfer of double suicide gene under the regulation of the KDR promoter. This finding may provide an optional way to target gene therapy of malignant tumors by abrogation of tumor blood vessels.

Functional nsSNPs from carcinogenesis-related genes expressed in breast tissue: potential breast cancer risk alleles and their distribution across human populations

Although highly penetrant alleles of BRCA1 and BRCA2 have been shown to predispose to breast cancer, the majority of breast cancer cases are assumed to result from the presence of low-moderate penetrant alleles and environmental carcinogens. Non-synonymous single nucleotide polymorphisms (nsSNPs) are hypothesised to contribute to disease susceptibility and approximately 30 per cent of them are predicted to have a biological significance. In this study, we have applied a bioinformatics-based strategy to identify breast cancer-related nsSNPs from 981 carcinogenesis-related genes expressed in breast tissue. Our results revealed a total of 367 validated nsSNPs, 109 (29.7 per cent) of which are predicted to affect the protein function (functional nsSNPs), suggesting that these nsSNPs are likely to influence the development and homeostasis of breast tissue and hence contribute to breast cancer susceptibility. Sixty-seven of the functional nsSNPs presented as commonly occurring nsSNPs (minor allele frequencies ≥ 5 per cent), representing excellent candidates for breast cancer susceptibility. Additionally, a non-uniform distribution of the common functional nsSNPs among different human populations was observed: 15 nsSNPs were reported to be present in all populations analysed, whereas another set of 15 nsSNPs was specific to particular population(s). We propose that the nsSNPs analysed in this study constitute a unique resource of potential genetic factors for breast cancer susceptibility. Furthermore, the variations in functional nsSNP allele frequencies across major population backgrounds may point to the potential variability of the molecular basis of breast cancer predisposition and treatment response among different human populations.