Different classes of plant hormones and different wavelengths of light act through specific signal transduction mechanisms to coordinate higher plant development. A specific prephenate dehydratase protein (PD1) was discovered to have a strong interaction with the sole canonical G-protein Gα-subunit (GPA1) in Arabidopsis (Arabidopsis thaliana). PD1 is a protein located in the cytosol, present in etiolated seedlings, with a specific role in blue light-mediated synthesis of phenylpyruvate and subsequently of phenylalanine (Phe). Insertion mutagenesis confirms that GPA1 and the sole canonical G-protein-coupled receptor (GCR1) in Arabidopsis also have a role in this blue light-mediated event. In vitro analyses indicate that the increase in PD1 activity is the direct and specific consequence of its interaction with activated GPA1. Because of their shared role in the light-mediated synthesis of phenylpyruvate and Phe, because they are iteratively interactive, and because activated GPA1 is directly responsible for the activation of PD1; GCR1, GPA1, and PD1 form all of or part of a signal transduction mechanism responsible for the light-mediated synthesis of phenylpyruvate, Phe, and those metabolites that derive from that Phe. Data are also presented to confirm that abscisic acid can act through the same pathway. An additional outcome of the work is the confirmation that phenylpyruvate acts as the intermediate in the synthesis of Phe in etiolated plants, as it commonly does in bacteria and fungi.

Purpose: Non-small cell lung cancer (NSCLC) has an overall 5-year survival of <15%; however, the 5-year survival for stage I disease is over 50%. Unfortunately, 75% of NSCLC is diagnosed at an advanced stage not amenable to surgery. A convenient serum assay capable of unambiguously identifying patients with NSCLC may provide an ideal diagnostic measure to complement computed tomography-based screening protocols.Experimental Design: Standard immunoproteomic method was used to assess differences in circulating autoantibodies among lung adenocarcinoma patients relative to cancer-free controls. Candidate autoantibodies identified by these discovery phase studies were translated into Luminex-based "direct-capture" immunobead assays along with 10 autoantigens with previously reported diagnostic value. These assays were then used to evaluate a second patient cohort composed of four discrete populations, including: 117 NSCLC (81 T 1-2 N 0 M 0 and 36 T 1-2 N 1-2 M 0 ), 30 chronic obstructive pulmonary disorder (COPD)/ asthma, 13 nonmalignant lung nodule, and 31 "normal" controls. Multivariate statistical methods were then used to identify the optimal combination of biomarkers for classifying patient disease status and develop a convenient algorithm for this purpose.Results: Our immunoproteomic-based biomarker discovery efforts yielded 16 autoantibodies differentially expressed in NSCLC versus control serum. Thirteen of the 25 analytes tested showed statistical significance (Mann-Whitney P < 0.05 and a receiver operator characteristic "area under the curve" over 0.65) when evaluated against a second patient cohort. Multivariate statistical analyses identified a six-biomarker panel with only a 7% misclassification rate.Conclusions: We developed a six-autoantibody algorithm for detecting cases of NSCLC among several high-risk populations. Population-based validation studies are now required to assign the true value of this tool for identifying early-stage NSCLC. Clin Cancer Res; 16(13); 3452-62. ©2010 AACR.Lung cancer remains the leading cause of cancer death nationwide, with ∼160,000 deaths predicted in the United States in 2009 (1). Non-small cell lung cancer (NSCLC) accounts for 80% of all lung cancers and has a poor overall 5-year survival rate of ∼15% (2-4). This low survival rate is largely attributed to the fact that >75% of patients present with local or distant metastasis at diagnosis, which are associated with a 21% and 3% 5-year survival, respectively (2,3,5). In contrast to these dismal figures, stage I disease is associated with a 50% to 67% 5-year survival but accounts for only 15% of patients (2). This suggests that if patients could be diagnosed at an earlier stage, when a complete surgical resection offers the greatest potential for a cure, the mortality associated with this disease could be reduced.To that end, considerable efforts have been undertaken to produce an effective screening method for early NSCLC. In the 1950s, trials of chest X-rays alone or in combination with sputum analysis were com...

Purpose: Current standard of care for neovascular eye diseases require repeated intravitreal bolus injections of anti-vascular endothelial growth factors (anti-VEGFs). The purpose of this study was to validate a degradable microsphere-thermoresponsive hydrogel drug delivery system (DDS) capable of releasing bioactive aflibercept in a controlled and extended manner for 6 months. Materials and Methods:The DDS was fabricated by suspending aflibercept-loaded poly(lactic-coglycolic acid) microspheres within a biodegradable poly(ethylene glycol)-co-(Llactic acid) diacrylate/N-isopropylacrylamide (PEG-PLLA-DA/NIPAAm) thermoresponsive hydrogel. Encapsulation efficiency of DDSs and in vitro release profiles were characterized by iodine-125 radiolabeled aflibercept. The degradation of hydrogel was determined by dry weight changes. The cytotoxicity from degraded DDS byproducts was investigated by quantifying cell viability using LIVE/DEAD® assay. In addition, dot blot and enzyme-linked immunosorbent assay were used to determine the bioactivity of released drug. Finally, morphology of microspheres and hydrogel were investigated by cryo-scanning electron microscopy before and after thermal transformation. Results:The microsphere-hydrogel DDS was capable of releasing bioactive aflibercept in a controlled and extended manner for 6 months. The amount and rate of aflibercept release can be controlled by both the cross-linker concentration and microspheres load amount. The initial burst (release within 24 h) was from 37.35 ± 4.92 to 74.56 ± 6.16 μg (2 and 3 mM hydrogel, each loaded with 10 and 20 mg/ml of microspheres, respectively), followed by controlled drug release of 0.07-0.15 μg/day. Higher PEG-PLLA-DA concentration (3 mM) degraded faster than the lower concentration (2 mM). No significant cytotoxicity from degraded DDS byproducts was found for all investigated time points. Bioactivity of released drug was maintained at therapeutic level over entire release period.

The cAMP-PKA cascade is a recognized signaling pathway important in inhibition of inflammatory injury events such as endothelial permeability and leucocyte trafficking, and a critical target of regulation is believed to be inhibition of Rho proteins. Here, we hypothesize that PKA directly phosphorylates GTP dissociation inhibitor (GDI) to negatively regulate Rho activity. Amino acid analysis of GDIalpha showed two potential protein kinase A (PKA) phosphorylation motifs, Ser(174) and Thr(182). Using in vitro kinase assay and mass spectrometry, we found that the purified PKA catalytic subunit phosphorylated GDIalpha-GST fusion protein and PKA motif-containing GDIalpha peptide at Ser(174), but not Thr(182). Transfection of COS-7 cells with mutated full-length GDIalpha at Ser(174) to Ala(174) (GDIalpha-Ser(174A)) abrogated the ability of cAMP to phosphorylate GDIalpha. However, mutation of Thr(182) to Ala(182) (GDIalpha-Thr(182A)) did not abrogate, and cAMP increased phosphorylation of GDIalpha to a similar extent as wild-type GDIalpha transfectants. The mutant GDIalpha-Ser(174A), but not GDIalpha-Thr(182A), was unable to prevent cAMP-mediated inhibition of Rho-dependent serum-response element reporter activity. Furthermore, the mutant GDIalpha-Ser(174A) was unable to prevent the thrombin-induced RhoA activation. Coprecipitation studies indicated that neither mutation of the PKA consensus sites nor phosphorylation alter GDIalpha binding with RhoA, suggesting that phosphorylation of Ser(174) regulated preformed GDIalpha-RhoA complexes. The findings provide strong support that the selective phosphorylation at Ser(174) by PKA is a signaling pathway in the negative regulation of RhoA activity and therefore could be a potential protective mechanism for inflammatory injury.