Epigenetic biomarkers in lung cancer

Lung cancer mortality is strongly associated with the predominant diagnosis of late stage lesions that hampers effective therapy. Molecular biomarkers for early lung cancer detection is an unmet public health need and the lung cancer research community worldwide is putting a lot of effort to utilise major lung cancer population programmes in order to develop such molecular tools. The study of cancer epigenetics in the last decade has radically altered our views in cancer pathogenesis, providing new insights in biomarker development for risk assessment, early detection and therapeutic stratification. DNA methylation and miRNAs have rapidly emerged as potential biomarkers in body fluids showing promise to assist the clinical management of lung cancer. These new developments are exemplified in this review, demonstrating the huge potential of clinical cancer epigenetics, but also critically discussing the necessary validation steps to bring epigenetic biomarkers towards clinical implementation and the weaknesses of current biomarker studies.     

Augmentation therapy with alpha-lipoic acid and desvenlafaxine: A future target for treatment of depression?

This study was designed to investigate the possible antidepressant effects of the antioxidant alpha-lipoic acid (ALA) as a stand-alone treatment or in association with desvenlafaxine (DVS) in the chronic corticosterone (CORT)-induced depression model. The depression model was induced by repeated administrations of CORT (20 mg/kg, subcutaneous) in mice over a period of 14 days. Between days 15 and 21, a randomized group of mice received DVS (10 or 20 mg/kg, per os [PO]), ALA (100 or 200 mg/kg, PO), or a combination of DVS (10 or 20 mg/kg, PO) and ALA (100 or 200 mg/kg, PO) along with the CORT injections for the remaining 7 days. Other groups of mice received DVS (10 or 20 mg/kg, PO) or ALA (100 or 200 mg/kg, PO) alone. Open field test, elevated plus maze (EPM) test, tail suspension test (TST), and forced swimming test (FST) were carried out 1 h after the last injection of CORT. Repeated CORT injections induced anxiety-like and depressive-like behaviors as observed by decreased open arms entries in the EPM test and increased immobility time in the TST and FST. The administration of DVS and ALA alone was able to reverse the increases in the immobility time. The combination of ALA and DVS potentiated the observed effects of DVS. These results suggest that augmentation therapy with the addition of antioxidant drugs may be an important pharmacological approach for the treatment of depression.     

Genetic polymorphisms of cytochrome P450c17α (CYP17) and progesterone receptor genes (PROGINS) in the assessment of endometriosis risk

We designed the present study in order to evaluate the eventual role of polymorphisms in the genes encoding cytochrome P450c17α (CYP17) and the progesterone receptor (PROGINS) as risk factors for endometriosis development. Eligible cases consisted of 121 women with surgically confirmed endometriosis who underwent treatment in a hospital in São Paulo, Brazil during the period from September 2003 to September 2005. The 281 controls were participants with normal gynecological as well as pelvic ultrasound evaluation, who did not have any gynecological conditions during their reproductive lives such as pelvic pain and/or dyspareunia nor infertility history. Genomic DNA was obtained from buccal cells and processed for DNA extraction using the GFX DNA extraction kit (GE Healthcare). The CYP17 (?34T→C) polymerase chain reaction–restriction fragment length polymorphism assay has been described previously, as has the progesterone receptor polymorphism (PROGINS) detection assay. PROGINS heterozygosis genotype frequencies were shown to be statistically higher in endometriosis cases compared with controls. On the other hand, differences in the CYP17 polymorphism (?34T → C) frequencies were not even close to significance (p = 0.278) according to our findings.     

Lung cancer alters the hydrolysis of nucleotides and nucleosides in platelets

Background

The nucleotides and nucleosides of adenine are signaling molecules related to thromboregulation and modulation of immune responses in patients with malignancies. Thus, this study aims to determine NTPDase, 5′-nucleotidase, ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) and adenosine deaminase (ADA) activities in the platelets of patients with lung cancer.

Methods

We collected blood samples from patients (n = 33) previously treated for lung cancer with chemotherapy. Patients were classified as stage IIIb and IV according to the Union for International Cancer Control (UICC).

Results

Patients showed a significant decrease in the hydrolysis of adenosine diphosphate (ADP) and adenosine, whereas the adenosine monophosphate (AMP) hydrolysis and platelet aggregation were significantly increased in this group. Adenosine triphosphate (ATP) hydrolysis did not show significant results between the group of patients and the control group.

Conclusions

We may suggest that ectonucleotidases as well as ADA are enzymes involved in thromboembolic events but especially here we may see that they are also directly involved in the generation of adenosine formation in the cancer patient circulation.     

Nicotine alters the ectonucleotidases activities in lymphocytes: In vitro and in vivo studies

The aim of the present study was to investigate the effects in vivo and in vitro of nicotine, an important immunosuppressive agent, on NTPDase and ADA activities in lymphocytes of adult rats. The following nicotine doses in vivo study were evaluated: 0.0, 0.25 and 1.0 mg/kg/day injected subcutaneously in rats for 10 days. The activity of the enzymes were significantly decreased with nicotine 0.25 and 1 mg/kg which inhibited ATP (22%, 54%), ADP (44%, 30%) hydrolysis and adenosine (43%, 34%) deamination, respectively. The expression of the protein NTPDase in rat lymphocytes was decreased to nicotine 1 mg/kg and the lymphocytes count was decreased in both nicotine doses studied. The purine levels measured in serum of the rats treated with nicotine 0.25 mg/kg significantly increased to ATP (39%), ADP (39%) and adenosine (303%). The nicotine exposure marker was determinate by level of cotinine level which significantly increased in rats treated with nicotine 0.25 (39%) and 1 mg/kg (131%) when compared to rats that received only saline. The second set of study was in vitro assay which the ATP-ADP-adenosine hydrolysis were decreased by nicotine concentrations 1 mM (0% - 0% - 16%, respectively), 5 mM (42% - 32% - 74%, respectively), 10 mM (80% - 27% - 80%, respectively) and 50 mM (96% - 49% - 98%, respectively) when compared with the control group. We suggest that alterations in the activities of these enzymes may contribute to the understanding of the mechanisms involved in the suppression of immune response caused by nicotine.     

Smoking History Decreases Survival in Patients with Squamous Cell Carcinoma of the Mouth: A Retrospective Study with 15 Years of Follow-up

Background: The purpose of this study was to evaluate the influence of smoking history on the clinical-pathological,sociodemographic and prognostic characteristics of patients with oral squamous cell carcinoma (SCC).Materials and Methods: A retrospective cohort study was carried out with the records of 136 smokers with SCC and68 nonsmokers with oral SCC who were diagnosed and treated at Haroldo Juaçaba Hospital (2000-2014). Data onpatient sex, age, race, education level, tumor location, tumor size, lymph node involvement, distant metastasis, treatmenttype, marital status, method of health care access (public or private health systems) and overall survival (15 years) wereanalyzed by the X² test, Mantel-Cox tests and multinomial and Cox logistic regression models (SPSS 20.0, p <0.05).Results: Smoking history was directly associated with male sex (p <0.001), low levels of education (p = 0.001), tumors ofthe mouth and palate (p = 0.001), stage T3/4 tumors (p = 0.014), lymph node metastasis (N+) (p = 0.024), palliativetreatment (p = 0.024) and receiving health care through the public health system (p = 0.006), with education levelbeing the only independently associated factor (p = 0.039). Lower survival was observed in patients who were smokers(p = 0,002), with low levels of education (p = 0.001), who had stage T3/4 tumors (p = 0.004), with N+ (p = 0.021), andhad received palliative treatment (p = 0.002). Age (>65 years old, p = 0.015) and T staging (T3/4, p = 0.033) decreasedthe survival of SCC patients regardless of the other factors. Conclusions: Smoking history had an independent associationwith low education level and a history of alcoholism, and survival was negatively associated with older age and largertumor size, which were more prevalent in smokers.     

Hepatic acute-phase proteins control innate immune responses during infection by promoting myeloid-derived suppressor cell function

Acute-phase proteins (APPs) are an evolutionarily conserved family of proteins produced mainly in the liver in response to infection and inflammation. Despite vast pro- and antiinflammatory properties ascribed to individual APPs, their collective function during infections remains poorly defined. Using a mouse model of polymicrobial sepsis, we show that abrogation of APP production by hepatocyte-specific gp130 deletion, the signaling receptor shared by IL-6 family cytokines, strongly increased mortality despite normal bacterial clearance. Hepatic gp130 signaling through STAT3 was required to control systemic inflammation. Notably, hepatic gp130–STAT3 activation was also essential for mobilization and tissue accumulation of myeloid-derived suppressor cells (MDSCs), a cell population mainly known for antiinflammatory properties in cancer. MDSCs were critical to regulate innate inflammation, and their adoptive transfer efficiently protected gp130-deficient mice from sepsis-associated mortality. The hepatic APPs serum amyloid A and Cxcl1/KC cooperatively promoted MDSC mobilization, accumulation, and survival, and reversed dysregulated inflammation and restored survival of gp130-deficient mice. Thus, gp130-dependent communication between the liver and MDSCs through APPs controls inflammatory responses during infection.Sepsis is a major cause of mortality worldwide characterized by a dysregulated inflammatory response to infection (Hotchkiss and Karl, 2003). Excessive inflammation accounts for serious complications, but unfortunately, strategies targeting key proinflammatory mediators have had only very limited success (Fisher et al., 1996; Riedemann et al., 2003), demonstrating the complex pathogenesis of the disorder that is determined by a variety of both pathogen and host factors. Notably, patients with chronic liver diseases have significantly increased risk of acquiring sepsis and its accompanying complications, and thus have higher sepsis-related mortality, with it accounting for 30% of all deaths in cirrhotic patients (Foreman et al., 2003). The underlying mechanisms for this clinical observation are only partially understood.The liver is the major source of acute-phase proteins (APPs), which are defined as proteins whose serum levels change by >25% during inflammation (Gabay and Kushner, 1999), and they are regarded as important components of the innate immune response to infection (Medzhitov, 2007). Many APPs are known as potent opsonins (Shah et al., 2006) and activators of innate immune cells such as neutrophils (Cheng et al., 2008a), but they also have antiinflammatory properties (Zouki et al., 1997). Because of the large diversity of APPs with both pro- and antiinflammatory functions (Gabay and Kushner, 1999), their overall role during infections is still not well defined.IL-6 is widely viewed as the major inducer of APP production in hepatocytes (Ritchie and Fuller, 1983). However, APP production in IL-6–deficient mice is only partly impaired and varies depending on the stimulus (Kopf et al., 1994). This strongly suggests redundant functions of the IL-6 family cytokines, a large group of cytokines that share the common signaling receptor gp130 (Murakami et al., 1993), or compensatory APP induction by other cytokines such as TNF and IL-1β. Most IL-6 cytokines bind to a membrane-bound cognate receptor and form a signaling complex with two gp130 receptors. Phosphorylation of distinct tyrosines of the intracellular domains of gp130 leads to activation of STAT3 and/or Ras–mitogen-activated protein kinase (MAPK) signaling. To better define the function of the hepatic acute-phase response during sepsis and endotoxic shock, we investigated the role of gp130 and downstream intracellular signaling pathways in hepatocytes. Although local effects of hepatic gp130 deficiency have been well characterized (Klein et al., 2005), systemic consequences remain unknown.Innate immune cell activation is critical for host defense against invading microorganisms and for the subsequent generation of an adaptive immune response (Medzhitov, 2007). On the other hand, proinflammatory mediators produced by innate immune cells are considered key elements in the pathogenesis of severe sepsis and multiorgan failure (Rittirsch et al., 2008). Tight control of proinflammatory pathways is therefore critical for immune homeostasis and host survival. A complex network of activating and regulatory pathways controls innate immune responses. In this study, we postulated that the hepatic acute-phase response crucially contributes to this regulation. Because one of the major proinflammatory mediators in sepsis, IL-6, is known to be a strong stimulator of APP production in the liver, we hypothesized that the resulting acute-phase response potentially acts as a counterregulator of the initial inflammatory reaction. We investigated whether hepatic APPs affect the central and peripheral immune cell composition, which undergoes dramatic changes during infections and endotoxemia. Interestingly, a growing body of evidence highlights the capacity of myeloid-derived suppressor cells (MDSCs), a heterogeneous, immature population of myeloid (precursor) cells characterized by the expression of the myeloid lineage marker Gr1 and CD11b, to inhibit T cell responses (Movahedi et al., 2008; Gabrilovich and Nagaraj, 2009). Although MDSCs are best known and characterized for their role in tumor immune evasion and promotion of metastasis (Nagaraj et al., 2007; Yang et al., 2008), they have also been associated with other pathological conditions like trauma, inflammation, and autoimmune disease (Zhu et al., 2007; Haile et al., 2008). Moreover, it has been reported that MDSCs accumulate in the spleens of mice during polymicrobial sepsis and suppress T cell functions (Delano et al., 2007). However, to which extent MDSCs modify the course of disease or if they critically contribute to immune regulation during sepsis remains unclear.In the present study we find that gp130–STAT3 signaling in hepatocytes and subsequent APP production is required to control the inflammatory response by facilitating peripheral accumulation and survival of MDSCs in sepsis. We provide evidence that MDSCs can directly inhibit inflammatory immune responses and define them as a key autoregulatory component of the innate immune system during infection.     

Aspartic proteinases of Candida spp.: role in pathogenicity and antifungal resistance

Fungal infections represent a serious health risk as they are particularly prevalent in immunocompromised individuals. Candida spp. pathogenicity depends on several factors and secreted aspartic proteinases (Sap) are considered one of the most critical factors as they are associated with adhesion, invasion and tissue damage. The production of proteinases is encoded by a family of 10 genes known as SAP, which are distributed differently among the species. The expression of these genes may be influenced by environmental conditions, which generally result in a higher fungal invasive potential. Non‐pathogenic Candida spp. usually have fewer SAP genes, which are not necessarily expressed in the genome. Exposure to subinhibitory concentrations of antifungal agents promotes the development of resistant strains with an increased expression of SAP genes. In general, Candida spp. isolates that are resistant to antifungals show a higher secretion of Sap than the susceptible isolates. The relationship between Sap secretion and the susceptibility profile of the isolates is of great interest, although the role of SAPs in the development of resistance to antifungal agents remains still unclear. This review is the first one to address these issues.     

New Eugenol Glucoside‐based Derivative Shows Fungistatic and Fungicidal Activity against Opportunistic Candida glabrata

A new series of glucosides modified in their saccharide units were synthesized, evaluated against Candida sp., and compared to prototype 1 , an eugenol tetracetyl glucoside previously synthesized and shown to be active against Candida glabrata. Among the new glucosides, benzyl derivative 5 was the most promising, showing fungistatic activity at IC₅₀ 18.1  μ m against Candida glabrata (threefold higher than fluconazole) and fungicidal activity with a low IC₉₀ value of 36.2 μm . Moreover, the cytotoxic activity of compound 5 (CC₅₀: 580.9  μ m ), tested in peripheral blood mononuclear cells, suggests its potential as an agent to treat Candida glabrata infections, with a selectivity index of 32. The new eugenol glucoside 5 may be considered as a novel structural pattern in the development of new anti‐Candida drugs.