Steroid metabolism gene CYP17 polymorphism and the development of breast cancer.

The potential role of the polymorphism in the CYP17 gene was evaluated in a case-control study with 483 incident breast cancer patients and 482 population controls, all of homogenous Finnish origin. Our data disagree with the earlier suggestions that the minor A2 variant of CYP17 would pose an increased risk for developing advanced breast cancer. In contrast, a tendency of inverse association was found for premenopausal women carrying the A2 allele containing genotypes with a multivariate adjusted odds ratio of 0.58 approaching statistical significance (95% CI, 0.31-1.07). Agreeing with previous observations, the protective effect of later age at menarche (> or =13 years) was mainly limited to women with A1/A1 genotype, although this could only be seen in premenopausal women (odds ratio, 0.34; 95% CI, 0.15-0.76). Similarly, we found a remarkably lower risk for premenopausal women with at least one child (odds ratio, 0.22; 95% CI, 0.07-0.62) to be mainly attributable to the A1/A1 genotype. CYP17 genotypes may thus modify individual breast cancer proneness in certain subpopulations, although they appear not to have any major modifying role in the risk of this malignancy overall. Because these findings are based on relatively small numbers in stratified analysis, they should, however, be interpreted with caution before being confirmed in future studies.     

Prognostic significance of iNOS in epithelial ovarian cancer

OBJECTIVE: To study the association of inducible nitric oxide synthase (iNOS) expression with clinicopathological factors and prognosis in epithelial ovarian cancer. METHODS: The study included 301 patients with primary epithelial ovarian cancer. iNOS expression was evaluated by immunohistochemistry using a mouse monoclonal antibody. RESULTS: iNOS positivity was observed as granular deposits in the cancer cell cytoplasm. The mean percentage of iNOS-positive cells was 50% in primary tumors (n=301), and 62% in metastatic lesions (n=43). iNOS expression correlated significantly with histological subtype of the tumor, as high (> 70%) iNOS expression was observed in mucinous tumors (p=0.009). Poorly differentiated tumors showed a tendency to low (< or = 70%) iNOS expression but without statistical significance. Low iNOS expression associated also significantly with large primary residual tumor (p=0.007) and tumor recurrence (p=0.04). The 10-year prognosis of the patients with high iNOS expression was better in disease-related survival (DRS) (p=0.009). However, in multivariate analysis only FIGO stage, primary residual tumor, and grade of the tumor were independent prognostic factors for DRS, but not the iNOS expression. CONCLUSIONS: A major proportion of human epithelial ovarian cancers expressed iNOS. The positive expression was an indicator of better disease-related survival. However, iNOS positivity could not overcome the importance of clinicopathological factors in prediction of prognosis.     

Structural and mechanistic insights into VEGF receptor 3 ligand binding and activation

Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key drivers of blood and lymph vessel formation in development, but also in several pathological processes. VEGF-C signaling through VEGFR-3 promotes lymphangiogenesis, which is a clinically relevant target for treating lymphatic insufficiency and for blocking tumor angiogenesis and metastasis. The extracellular domain of VEGFRs consists of seven Ig homology domains; domains 1–3 (D1-3) are responsible for ligand binding, and the membrane-proximal domains 4–7 (D4-7) are involved in structural rearrangements essential for receptor dimerization and activation. Here we analyzed the crystal structures of VEGF-C in complex with VEGFR-3 domains D1-2 and of the VEGFR-3 D4-5 homodimer. The structures revealed a conserved ligand-binding interface in D2 and a unique mechanism for VEGFR dimerization and activation, with homotypic interactions in D5. Mutation of the conserved residues mediating the D5 interaction (Thr446 and Lys516) and the D7 interaction (Arg737) compromised VEGF-C induced VEGFR-3 activation. A thermodynamic analysis of VEGFR-3 deletion mutants showed that D3, D4-5, and D6-7 all contribute to ligand binding. A structural model of the VEGF-C/VEGFR-3 D1-7 complex derived from small-angle X-ray scattering data is consistent with the homotypic interactions in D5 and D7. Taken together, our data show that ligand-dependent homotypic interactions in D5 and D7 are essential for VEGFR activation, opening promising possibilities for the design of VEGFR-specific drugs.     

A co-opted steroid synthesis gene,maintained in sorghum but not maize,is associated with a divergence in leaf wax chemistry

Virtually all land plants are coated in a cuticle, a waxy polyester that prevents nonstomatal water loss and is important for heat and drought tolerance. Here, we describe a likely genetic basis for a divergence in cuticular wax chemistry between Sorghum bicolor, a drought tolerant crop widely cultivated in hot climates, and its close relative Zea mays (maize). Combining chemical analyses, heterologous expression, and comparative genomics, we reveal that: 1) sorghum and maize leaf waxes are similar at the juvenile stage but, after the juvenile-to-adult transition, sorghum leaf waxes are rich in triterpenoids that are absent from maize; 2) biosynthesis of the majority of sorghum leaf triterpenoids is mediated by a gene that maize and sorghum both inherited from a common ancestor but that is only functionally maintained in sorghum; and 3) sorghum leaf triterpenoids accumulate in a spatial pattern that was previously shown to strengthen the cuticle and decrease water loss at high temperatures. These findings uncover the possibility for resurrection of a cuticular triterpenoid-synthesizing gene in maize that could create a more heat-tolerant water barrier on the plant’s leaf surfaces. They also provide a fundamental understanding of sorghum leaf waxes that will inform efforts to divert surface carbon to intracellular storage for bioenergy and bioproduct innovations.

Demand for both food and energy are projected to increase substantially over the coming decades (1). Meeting these needs while minimizing negative impacts on our environment, health, and fresh water supply is one of the largest challenges currently faced by humanity. A component of meeting this challenge is identifying, improving, and deploying high-yield, low-input, multiuse crops (2). One candidate is sorghum (Sorghum bicolor), a multiuse C4 grass crop. Sorghum is exceptionally tolerant of hot and dry climates, being native to arid regions (3, 4), and the genus contains considerable natural diversity that offers great potential for the improvement of existing biomass and grain varieties, as well as sequenced landraces that are adapted to specific, relatively extreme environments (5, 6). Sorghum has a relatively small, sequenced genome (7), its grain is naturally gluten-free (8), and it can be genetically transformed (9, 10). Thus, sorghum is an excellent study system for advancing our understanding of the physiological basis for crop drought tolerance and heat resistance. This is particularly true when comparisons are made between sorghum and its close relative maize (Zea mays), one of the most widely grown crops in the world, but also a crop that suffers major yield losses due to drought. Indeed, investigators in this area have identified a variety of physiological mechanisms underlying sorghum’s positive qualities (11–14). However, there is still a critical need for mechanistic details underlying these processes and how such differ between sorghum and maize. Until these gaps are filled, it will be difficult to further enhance sorghum’s positive qualities, and it will not be possible to transfer these qualities to other crop species such as maize.Though plants deploy diverse mechanisms to protect themselves against drought and heat, one of the most widespread (found in essentially all land plants), is a hydrophobic, aerial surface coating called the cuticle. This structure is composed of a fatty acid-derived polyester scaffold called cutin, inside and on top of which accumulates wax, a mixture of hydrophobic compounds that seal the surface against the movement of water (15). While cutin makes major contributions to a cuticle’s biomechanical properties and, at least in some species, contributes to pathogen resistance (16, 17), waxes are primarily responsible for preventing water from crossing the leaf–atmosphere interface (18, 19). It is well established that wax mixtures vary between plant species, organs, tissues, cell types, and across leaf developmental stages (20–23). This suggests wax mixtures are tuned to meet the challenges faced by specific plant surfaces in their immediate environment. This notion is supported by experiments on transgenic plants with altered wax amounts and/or wax mixture compositions: They exhibit altered water barrier properties (18, 24–27). These studies also demonstrate that plant drought tolerance may be improved through cuticle engineering, thus further underscoring the importance of understanding the waxes of a drought tolerant plant like sorghum.Based on the importance of sorghum waxes, the primary objective of this study was to develop our fundamental knowledge in this area, particularly in a comparative context with maize. Previous work has demonstrated that the juvenile-to-adult transition, a developmental event in a plant’s life cycle, can be associated with major changes in surface wax characteristics (28, 29). Accordingly, this investigation began by analyzing sorghum leaf waxes over the course of the plant’s development, then aimed to understand underlying biosynthetic processes as well as the evolutionary history of leaf wax biosynthesis in sorghum, all relative to analogous processes in maize. To accomplish this, the present study combined detailed chemical analyses of the sorghum leaf surface, bioinformatics-guided characterization of sorghum wax synthesis genes by heterologous expression, as well as ancestral state reconstruction and a comparative genomics analysis of critical sorghum wax synthesis genes across six grass species, including sorghum and maize. Considered together, the results indicate that sorghum has maintained a form of wax synthesis likely preset in the common ancestor of maize and sorghum that relies on a neofunctionalized steroid biosynthesis gene capable of generating uncommon triterpenoid wax chemicals. Our analyses show that this gene is present in the maize genome but is truncated and not expressed. This, together with reports of triterpenoids being absent from the maize leaf surface (30), suggest a likely genetic basis for the observed divergence in sorghum and maize leaf wax chemistry.     

Investigation on the agonistic and antagonistic biological activities of synthetic Chlamydia lipid A and its use in in vitro enzymatic assays

The synthetic 1,4'-bisphosphorylated penta-acyl and tetra-acyl lipid A structures representing the major molecular species of natural chlamydial lipid A were tested for their endotoxic activities as measured by interleukin-8 release from human embryonic kidney (HEK) 293 cells expressing Toll-like receptor (TLR) 2 or TLR4. Both compounds were unable to activate HEK293 cells transiently transfected with TLR2. The penta-acyl lipid A was a weak activator of HEK293 cells expressing TLR4/MD-2/CD14 whereas tetra-acyl lipid A was inactive even at high concentrations. The weak activity of the penta-acyl lipid A could be antagonized by the tetra-acyl derivative of Escherichia coli lipid A (compound 406) or the anti-CD14 monoclonal antibody MEM-18. Both, tetra- and pentaacyl lipid A were unable to antagonize the activity of synthetic E. coli-type lipid A (compound 506) or smooth lipopolysaccharide of Salmonella enterica serovar Friedenau. Tetra- and penta-acyl lipid A served as acceptors for Kdo transferases from E. coli, Chlamydia trachomatis and Chlamydophila psittaci as shown by in vitro assays and detection of the products by thin layer chromatography and immune staining with monoclonal antibody.     

Psychosocial predictors of physical activity and health-related quality of life among adults with physical disabilities: an integrative framework

BackgroundPeople with disabilities report lower physical activity (PA) and health-related quality of life (HRQOL) levels than people without disabilities. Therefore, it is important to identify factors that motivate individuals with disabilities to be physically active and thus increase their HRQOL.ObjectivesThe purpose of the study was to prospectively explore the effects of past theory of planned behavior (TPB) constructs on future (6-month) HRQOL (physical and mental health) through past stages of change (SOC) and future (6-month) PA among adults with physical disabilities. Two models were tested whereby the SOC and PA served as the mediators between the TPB constructs, physical health (PH-Model), and mental health (MH-Model). It was hypothesized that both models would fit the sample data.MethodsParticipants were 141 adults with physical disabilities (mean age = 46.04, females = 70.9%). The online survey was completed at two different time periods. First, the TPB constructs and SOC were assessed using self-report standardized questionnaires. Six months later, participants completed standardized self-report scales about their PA and HRQOL levels. Using LISREL 8, two path analyses were conducted to examine the two study models (PH-Model and MH-Model).ResultsBased on the two path analyses, attitude had the highest effect on SOC followed by perceived behavioral control within both well-fit models. The PH-Model explained more variance in PA (26%) and physical health (55%) than the MH-Model.ConclusionsHealth promoters should reinforce both positive intentions and behavioral experiences to increase PA and HRQOL among adults with physical disabilities.     

CD44 expression and its relationship with MMP-9, clinicopathological factors and survival in oral squamous cell carcinoma

We investigated the expression of CD44 and MMP-9 in primary oral squamous cell carcinoma (OSCC) and evaluated their association with each other and clinicopathological factors as well as their prognostic value during long term follow up. Histological samples from 138 OSCC patients were immunohistochemically stained for the expression of CD44 and MMP-9. The staining results were compared with conventional prognostic factors and their impacts to patients' prognosis were also studied with survival analyses. Irregular staining of CD44 in tumour cells was associated with poor tumour differentiation (p=0.003), higher clinical stage (III-IV) (p=0.049), and the presence of T3-4 tumour stage (p=0.03). Strong stromal MMP-9 staining intensity was correlated with poor tumour differentiation (p=0.03). In univariate survival analysis irregular staining of CD44 in tumour cells was related to poor disease free and overall survival (p=0.001 and p<0.001, respectively). In multivariate analysis CD44 staining was a significant independent predictor for overall (p=0.03) and disease free survival (p=0.003). MMP-9 expression showed no statistical significance in survival analyses. Strong stromal staining intensity of MMP-9 correlated with irregular staining of CD44 in tumour cells, but had no prognostic significance in the present cohort. However, irregular staining of CD44 predicted more advanced disease and shortened survival of the patients.     

Health beliefs and physical activity behavior in adults with multiple sclerosis

BackgroundUnderstanding how health beliefs intersect with physical activity in people with multiple sclerosis (MS) is an important step in developing effective activity promotion programs.ObjectiveThe purpose of the study was to employ the Health Belief Model (HBM) to assess the health beliefs of adults with MS and examine the relationship between health beliefs and physical activity behavior.MethodParticipants with MS (N = 384) completed a web-based survey assessing the following HBM constructs: perceived susceptibility and seriousness of negative health outcomes, perceived benefits and barriers to physical activity, cues to action, and self-efficacy. Self-reported physical activity was also surveyed.ResultsParticipant perceptions of susceptibility to negative health outcomes were focused more on physical conditioning and functioning rather than on general health conditions. The most important HBM predictors of physical activity were self-efficacy and perceived benefits of exercise. Even when controlling for the significant effects of disability level on physical activity, self-efficacy and perceived benefits remained robust exercise predictors.ConclusionIndividuals with MS believe they can benefit from physical activity and remain healthy even in the context of their disease. They also acknowledge the fact that their disability levels limit their exercise capabilities. Given that self-efficacy and perceived benefits of activity are important determinants of physical activity, health promotion efforts should be directed at these modifiable factors.