Manipulating anthocyanin composition in Vitis vinifera suspension cultures by elicitation with jasmonic acid and light irradiation

Jasmonic acid altered the accumulation of major anthocyanins in Vitis vinifera cell culture. Peonidin 3-glucoside content at day three was increased from 0.3 to 1.7 mg g^–1 dry cell wt while other major anthocyanins were increased by smaller increments. By day 14, the content of methylated and acylated anthocyanins (peonidin 3-p-coumaroylglucoside and malvidin 3-p-coumaroylglucoside) was 6.3 mg g^–1 DCW, in response to treatment with jasmonic acid, and comprising 45% (w/w) of total anthocyanins. In comparison, the untreated control culture contained 1.2 mg g^–1 DCW which made up 32% (w/w) of total anthocyanins. Light further enhanced anthocyanin accumulation induced by jasmonic acid elicitation. The content of peonidin 3-glucoside at day 3 was 6.6 mg g^–1 DCW, 22-fold higher than control cultures while the content in response to light irradiation alone was 0.6 mg g^–1 DCW. When a highly pigmented cell line was elicited with jasmonic acid total anthocyanins increased from 9.2 to 20.7 mg g^–1 DCW, but there was no change in the anthocyanin composition.     

Lifestyle factors and Ki-ras mutations in colon cancer tumors

Heterogeneity in colon tumors implies that environmental, lifestyle, or genetic factors influence the type of mutations seen in tumors. In this study we evaluate the association between previously identified risk factors for colon cancer and Kirsten-ras (Ki-ras) mutations in tumors. The presence of Ki-ras mutations in codons 12 and 13 were determined in a population-based case-control study of colon cancer. Participants were between 30 and 79 years of age at time of diagnosis and include both men and women. Questionnaire data were used to obtain information on lifestyle factors. Valid study data and Ki-ras mutational status were available from 1428 cases of colon cancer, data from 2410 controls were available for comparative purposes. Participants with Ki-ras mutations were more likely to have proximal rather than distal tumors. Cigarette smoking, use of aspirin and/or NSAIDs, use of vitamin/mineral supplements, and consumption of caffeine were associated with both Ki-ras+ and Ki-ras- tumors; the associations were not confounded by dietary intake or other lifestyle factors. Among men, but not among women, those with low levels of physical activity were more likely to have a tumor with a Ki-ras mutation than one without a Ki-ras mutation. However, among women, those with a larger BMI were more likely to have a Ki-ras mutation in their tumor. Given the limited information available on what causes Ki-ras mutations, the information generated from this study indicates that these factors previously associated with colon cancer work through other disease pathways.     

Isoindolinone ureas: a novel class of KDR kinase inhibitors

A series of substituted isoindolinone ureas was prepared and evaluated for enzymatic and cellular inhibition of KDR kinase activity. Several of these analogs, such as 14c, are potent inhibitors of KDR both enzymatically (< 50 nM) and cellularly < or = 100 nM). A 3D KDR/CDK2/MAP kinase overlay model with several structurally related tyrosine kinase inhibitors was used to predict the binding interactions of the isoindolinone ureas with the KDR active site.     

PARP inhibitors for cancer therapy

Poly(ADP-ribose) polymerase 1 (PARP-1) is a zinc-finger DNA-binding enzyme that is activated by binding to DNA breaks. Poly(ADP-ribosyl)ation of nuclear proteins by PARP-1 converts DNA damage into intracellular signals that activate either DNA repair by the base-excision pathway or cell death. A family of 18 PARPs has been identified, but only the most abundant, PARP-1 and PARP-2, which are both nuclear enzymes, are activated by DNA damage. PARP inhibitors of ever-increasing potency have been developed in the 40 years since the discovery of PARP-1, both as tools for the investigation of PARP-1 function and as potential modulators of DNA-repair-mediated resistance to cytotoxic therapy. Owing to the high level of homology between the catalytic domains of PARP-1 and PARP-2, the inhibitors probably affect both enzymes. Convincing biochemical evidence, which has been corroborated by genetic manipulation of PARP-1 activity, shows that PARP inhibition is associated with increased sensitivity to DNA-alkylating agents, topoisomerase I poisons and ionising radiation. Novel PARP inhibitors of sufficient potency and suitable pharmacokinetic properties to allow evaluation in animal models have been shown to enhance the antitumour activity of temozolomide (a DNA-methylating agent), topoisomerase poisons and ionising radiation; indeed, the combination with temozolomide resulted in complete tumour regression in two independent studies. The combination of a PARP inhibitor and temozolomide is currently undergoing clinical evaluation for the first time.     

Atlas – a data warehouse for integrative bioinformatics

Background  

We present a biological data warehouse called Atlas that locally stores and integrates biological sequences, molecular interactions, homology information, functional annotations of genes, and biological ontologies. The goal of the system is to provide data, as well as a software infrastructure for bioinformatics research and development.     

Conformation of aspartate aminotransferase in crystals

X-ray study of chicken cytosolic aspartate aminotransferase revealed conformational changes in the protein of two kinds: (1) a shift of the small domain adjacent to substrate-binding area due to interaction of the protein with two carboxyl groups of substrate and (2) a change in inclination of the coenzyme plane due to replacement of C = N bond of the coenzyme with Lys-258 by C = N bond with a substrate. An asymmetry in subunit behaviour is observed in both cases: the domain is shifted in one subunit and the coenzyme is rotated in other. Substrate-binding properties of each subunit are strictly dependent on the protein conformation in substrate-binding area.     

Thienopyridine urea inhibitors of KDR kinase

A series of substituted thienopyridine ureas was prepared and evaluated for enzymatic and cellular inhibition of KDR kinase activity. Several of these analogs, such as 2, are potent inhibitors of KDR (<10 nM) in both enzymatic and cellular assays. Further characterization of inhibitor 2 indicated that this analog possessed excellent in vivo potency (ED50 2.1 mg/kg) as measured in an estradiol-induced mouse uterine edema model.     

Spatiotemporal Optoacoustic Mapping of Tumor Hemodynamics in a Clinically Relevant Orthotopic Rabbit Model of Head and Neck Cancer

The purpose of this study was to investigate the usefulness of photoacoustic imaging (PAI) for spatiotemporal mapping of tumor hemodynamics in a rabbit model of head and neck carcinoma. Shope cottontail rabbit papilloma virus associated VX2 carcinomas were established in adult male New Zealand White rabbits (n = 9) by surgical transplantation of tumor tissue in the neck. Noninvasive PAI with co-registered ultrasound (US) was performed to longitudinally monitor tumor growth, oxygen saturation (%sO₂), and hemoglobin concentration (HbT). PAI findings were validated with Doppler sonography measures of percent vascularity (PV). Differences in tumor volumes, %sO₂, HbT, and PV values over time were analyzed using repeated-measures analysis of variance with multiple comparisons. Two-tailed Spearman correlation analysis was performed to determine the correlation coefficient (r) for comparisons between %sO₂, HbT, and tumor volume. US revealed a significant (P < .0001) increase in tumor volume over the 3-week period from 549 ± 260 mm³ on day 7 to 5055 ± 438 mm³ at 21 days postimplantation. Consistent with this aggressive tumor growth, PAI revealed a significant (P < .05) and progressive reduction in %sO₂ from day 7 (37.6 ± 7.4%) to day 21 (9.5 ± 2.1%). Corresponding Doppler images also showed a decrease in PV over time. PAI revealed considerable intratumoral spatial heterogeneity with the tumor rim showing two- to three-fold higher %sO₂ values compared to the core. Noninvasive PAI based on endogenous contrast provides a label-free method for longitudinal monitoring of temporal changes and spatial heterogeneity in thick head and neck tumors.