Role of modern radiation therapy in early stage Hodgkin's lymphoma: A young radiation oncologists’ perspective

The role of radiotherapy is well established in combined modality programs for early stage Hodgkin's lymphoma, but still debated with regards to late toxicity issues. Modern radiotherapy prescribing attitudes include lower doses and smaller fields, together with the implementation of sophisticated and dedicated delivery techniques. Aim of this review is to briefly discuss the current role of radiotherapy in this field and the potential future developments. Major trials conducted in recent years in early stage Hodgkin's lymphoma are critically reviewed and discussed with a focus on radiotherapy-related issues and with an attention to current treatment options by a “young” radiation oncologists’ perspective.     

Activation of Oncogenic Pathways in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause. The most recent hypotheses on IPF pathogenesis suggest a central role of epithelial cell damage, followed by a dysregulated molecular cross talk between epithelial cells and fibroblasts. Thus, IPF progression has often been assimilated to that of cancer, and several signaling patterns appear to be disrupted in both diseases. Here, we analyze the expression in an IPF series of a panel of molecules, which are known to play a role in tumorigenic process. Our findings, although preliminary, reveal that IPF landscape is enriched in neoplastic potential expressed in a context of complex genomic polyclonality and cellular heterogeneity. These results provide a rationale for further investigations aimed to exploit—in a similar fashion to cancer—targeted therapies for a “precision medicine” approach to IPF.     

Critical water contents at leaf,stem and root level leading to irreversible drought-induced damage in two woody and one herbaceous species

Plant water content is a simple and promising parameter for monitoring drought-driven plant mortality risk. However, critical water content thresholds leading to cell damage and plant failure are still unknown. Moreover, it is unclear whether whole-plant or a specific organ water content is the most reliable indicator of mortality risk. We assessed differences in dehydration thresholds in leaf, stem and root samples, hampering the organ-specific rehydration capacity and increasing the mortality risk. We also tested eventual differences between a fast experimental dehydration of uprooted plants, compared to long-term water stress induced by withholding irrigation in potted plants. We investigated three species with different growth forms and leaf habits i.e., Helianthus annuus (herbaceous), Populus nigra (deciduous tree) and Quercus ilex (evergreen tree). Results obtained by the two dehydration treatments largely overlapped, thus validating bench dehydration as a fast but reliable method to assess species-specific critical water content thresholds. Regardless of the organ considered, a relative water content value of 60% induced significant cell membrane damage and loss of rehydration capacity, thus leading to irreversible plant failure and death.     

Increased Hippocampal 5-Lipoxygenase mRNA Content in Melatonin-Deficient, Pinealectomized Rats

Abstract: Tryptophan hydroxylase, the initial and rate-limiting enzyme in the biosynthesis of the neurotransmitter serotonin, is activated by protein kinase A and calcium/calmodulin-dependent protein kinase. One important aspect of the regulation of any enzyme by a phosphorylation-dephosphorylation cascade, and one that is lacking for tryptophan hydroxylase, lies in the identification of its site of phosphorylation by protein kinases. Recombinant forms of brain tryptophan hydroxylase were expressed as glutathione S -transferase fusion proteins and exposed to protein kinase A. This protein kinase phosphorylates and activates full-length tryptophan hydroxylase. The inactive regulatory domain of the enzyme (corresponding to amino acids 1–98) was also phosphorylated by protein kinase A. The catalytic core of the hydroxylase (amino acids 99–444), which expresses high levels of enzyme activity, was neither phosphorylated nor activated by protein kinase A. Conversion of serine-58 to arginine resulted in the expression of a full-length tryptophan hydroxylase mutant that, although remaining catalytically active, was neither phosphorylated nor activated by protein kinase A. These results indicate that the activation of tryptophan hydroxylase by protein kinase A is mediated by the phosphorylation of serine-58 within the regulatory domain of the enzyme.     

Progression mechanisms in colon cancer: soluble interleukin-2 (IL-2) receptor,IL-2 plus anti-CD3 proliferative response and tumour stage correlations

Soluble interleukin-2 receptor (sIL-2R) levels have been found to be elevated in several clinical conditions, including disseminated solid neoplasms, whereas they are generally within the normal range in patients with locally limited neoplastic disease. The aim of the present study was to examine this in our colon cancer patients, and to assess if this situation can affect the in vitro activation of peripheral blood mononuclear cells (PBMC) examining the proliferative response to IL-2 and anti-CD3 monoclonal antibody, the IL-2 serum levels and the PBMC phenotype. The results show that sIL-2R levels were significantly correlated with the stage of the disease, showing an increase from stage I to stage IV; moreover, it is worth noting that the proliferative response to IL-2 plus anti-CD3 is significantly higher than to IL-2 alone in stage IV, without significant alteration in the numerical presence of T and natural killer cells. So it seems that in the peripheral blood of patients, connected with the disease progression, are present cellular populations showing a different response to activation, and that T cells acquire a better response condition than NK. Thus, since the T cellular population includes the tumour-specific cytotoxic precursor cells, this should be helpful for its tumour regressive activity, but it is conceivable that this population cannot perform its functions, owing to a deficiency in responsiveness of the specific ThCD4⁺ subpopulation.     

Higher alcohol and acetoin production by Zygosaccharomyces wine yeasts

Seventy strains of Zygosaccharomyces isolated from grape musts were investigated for their ability to produce higher alcohols and acetoin in synthetic medium and grape must. The Zygosaccharomyces strains produced generally low amounts of higher alcohols. Within this genus, Z. fermentati behaved differently from Z. bailii producing less isobutanol in synthetic medium and more amyl alcohols and isobutanol in grape must. Zygosaccharomyces fermentati did not form detectable amounts of acetoin in any conditions whereas Z. bailii produced it both in synthetic medium and in grape must. These strains were found to contribute to aroma and taste of wine.     

Soluble Receptor for Advanced Glycation End-products regulates age-associated Cardiac Fibrosis

Myocardial aging increases the cardiovascular risk in the elderly. The Receptor for Advanced Glycation End-products (RAGE) is involved in age-related disorders. The soluble isoform (sRAGE) acts as a scavenger blocking the membrane-bound receptor activation. This study aims at investigating RAGE contribution to age-related cardiac remodeling.We analyzed the cardiac function of three different age groups of female Rage-/- and C57BL/6N (WT) mice: 2.5- (Young), 12- (Middle-age, MA) and 21-months (Old) old. While aging, Rage-/- mice displayed an increase in left ventricle (LV) dimensions compared to age-matched WT animals, with the main differences observed in the MA groups. Rage-/- mice showed higher fibrosis and a larger number of α-Smooth Muscle Actin (SMA)+ cells with age, along with increased expression of pro-fibrotic Transforming Growth Factor (TGF)-β1 pathway components. RAGE isoforms were undetectable in LV of WT mice, nevertheless, circulating sRAGE declined with aging and inversely associated with LV diastolic dimensions. Human cardiac fibroblasts stimulated with sRAGE exhibited a reduction in proliferation, pro-fibrotic proteins and TGF-beta Receptor 1 (TGFbR1) expression and Smad2-3 activation. Finally, sRAGE administration to MA WT animals reduced cardiac fibrosis.Hence, our work shows that RAGE associates with age-dependent myocardial changes and indicates sRAGE as an inhibitor of cardiac fibroblasts differentiation and age-dependent cardiac fibrosis.     

Dual Catalytic Activity of Hydroxycinnamoyl-Coenzyme A Quinate Transferase from Tomato Allows It to Moonlight in the Synthesis of Both Mono- and Dicaffeoylquinic Acids

Tomato (Solanum lycopersicum), like other Solanaceous species, accumulates high levels of antioxidant caffeoylquinic acids, which are strong bioactive molecules and protect plants against biotic and abiotic stresses. Among these compounds, the monocaffeoylquinic acids (e.g. chlorogenic acid [CGA]) and the dicaffeoylquinic acids (diCQAs) have been found to possess marked antioxidative properties. Thus, they are of therapeutic interest both as phytonutrients in foods and as pharmaceuticals. Strategies to increase diCQA content in plants have been hampered by the modest understanding of their biosynthesis and whether the same pathway exists in different plant species. Incubation of CGA with crude extracts of tomato fruits led to the formation of two new products, which were identified by liquid chromatography-mass spectrometry as diCQAs. This chlorogenate:chlorogenate transferase activity was partially purified from ripe fruit. The final protein fraction resulted in 388-fold enrichment of activity and was subjected to trypsin digestion and mass spectrometric sequencing: a hydroxycinnamoyl-Coenzyme A:quinate hydroxycinnamoyl transferase (HQT) was selected as a candidate protein. Assay of recombinant HQT protein expressed in Escherichia coli confirmed its ability to synthesize diCQAs in vitro. This second activity (chlorogenate:chlorogenate transferase) of HQT had a low pH optimum and a high K_m for its substrate, CGA. High concentrations of CGA and relatively low pH occur in the vacuoles of plant cells. Transient assays demonstrated that tomato HQT localizes to the vacuole as well as to the cytoplasm of plant cells, supporting the idea that in this species, the enzyme catalyzes different reactions in two subcellular compartments.The importance of plant-based foods in preventing or reducing the risk of chronic disease has been widely demonstrated (Martin et al., 2011, 2013). In addition to vitamins, a large number of other nutrients in plant-based foods promote health and reduce the risk of chronic diseases; these are often referred to as phytonutrients. The presence of phytonutrients in fruit and vegetables is of significant nutritional and therapeutic importance, as many have been found to possess strong antioxidant activity (Rice-Evans et al., 1997). Phenolics are the most widespread dietary antioxidants and caffeoylquinic acids, such as chlorogenic acid (CGA), dicaffeoylquinic acids (diCQAs), and tricaffeoylquinic acids (triCQAs), play important roles in promoting health (Clifford, 1999; Niggeweg et al., 2004). CGA limits low density lipid oxidation (Meyer et al., 1998), diCQAs possess antihepatotoxic activity (Choi et al., 2005), and triCQAs reduce the blood Glc levels of diabetic rats (Islam, 2006). diCQA derivatives have been shown to protect humans from various kinds of diseases; diCQAs suppress melanogenesis effectively (Kaul and Khanduja, 1998), show anti-inflammatory activity in vitro (Peluso et al., 1995), and exhibit a selective inhibition of HIV replication (McDougall et al., 1998). The physiological effects of caffeoylquinic acid derivatives with multiple caffeoyl groups are generally greater than those of monocaffeoylquinic acids, perhaps because the antioxidant activity is largely determined by the number of hydroxyl groups present on the aromatic rings (Wang et al., 2003; Islam, 2006). Furthermore, both diCQAs and triCQAs may function as inhibitors of the activity of HIV integrase, which catalyzes the insertion of viral DNA into the genome of host cells (McDougall et al., 1998; Slanina et al., 2001; Gu et al., 2007).CGA is the major soluble phenolic in Solanaceous crops (Clifford, 1999) and the major antioxidant in the average U.S. diet (Luo et al., 2008), while different isomers of diCQAs have been identified in many crops such as coffee (Coffea canephora), globe artichoke (Cynara cardunculus), tomato (Solanum lycopersicum), lettuce (Lactuca sativa), and sweet potato (Ipomoea batatas; Clifford, 1999; Islam, 2006; Moco et al., 2006, 2007; Moglia et al., 2008). In tomato, CGA accounts for 75% and 35% of the total phenolics in mature green and ripe fruit, respectively, amounting to 2 to 40 mg 100 g^–1 dry weight (DW), although levels decline after ripening and during postharvest storage (Slimestad and Verheul, 2009). diCQAs and triCQAs also accumulate in tomato fruit (diCQAs, approximately 2 mg 100 g^–1 DW; and triCQAs, 1–2 mg 100 g^–1 DW; Chanforan et al., 2012).Three pathways (Villegas and Kojima, 1986; Hoffmann et al., 2003; Niggeweg et al., 2004) have been proposed for the synthesis of CGA: (1) the direct pathway involving caffeoyl-CoA transesterification with quinic acid by hydroxycinnamoyl-Coenzyme A:quinate hydroxycinnamoyl transferase (HQT; Niggeweg et al., 2004; Comino et al., 2009; Menin et al., 2010; Sonnante et al., 2010); (2) the route by which p-coumaroyl-CoA is first transesterified with quinic acid via hydroxycinnamoyl-Coenzyme A transferase (HCT) acyltransferase (Hoffmann et al., 2003; Comino et al., 2007), followed by the hydroxylation of p-coumaroyl quinate to 5-caffeoylquinic acid, catalyzed by C3′H (p-coumaroyl-3-hydroxylase; Schoch et al., 2001; Mahesh et al., 2007; Moglia et al., 2009); and (3) the use of caffeoyl-glucoside as the acyl-donor (Villegas and Kojima, 1986). In tomato, the synthesis of CGA involves transesterification of caffeoyl-CoA with quinic acid by HQT (Niggeweg et al., 2004).To date, it is not clear whether diCQAs are derived directly from the monocaffeoylquinic acids (such as CGA) through a second acyltransferase reaction involving an acyl-CoA or not, although their structural similarity provides good a priori evidence supporting this hypothesis. Recently the in vitro synthesis of 3,5-diCQA from CGA and CoA by HCT from coffee has been reported (Lallemand et al., 2012). By contrast, in sweet potato, an enzyme that catalyzes the transfer of the caffeoyl moiety of CGA to another molecule of CGA, leading to the synthesis of isochlorogenate (3,5-di-O-caffeoylquinate), has been described, but the corresponding gene has not been identified (Villegas and Kojima, 1986).We report a chlorogenate:chlorogenate transferase (CCT) activity leading to the synthesis of diCQAs in tomato fruits and describe how alternative catalysis, by a single enzyme, leads to the production of both CGA and diCQA in different cellular compartments.