Lysophosphatidic acid augments human hepatocellular carcinoma cell invasion through LPA1 receptor and MMP-9 expression

Lysophosphatidic acid (LPA), produced extracellularly by autotaxin (ATX), has diverse biological activities implicated in tumor initiation and progression, including increasing cell survival, angiogenesis, invasion and metastasis. ATX, LPA and the matrix metalloproteinase (MMP)-9 have all been implicated in hepatocellular carcinoma (HCC) invasion and metastasis. We, thus sought to determine whether ATX with subsequent LPA production and action, including induction of MMP-9 could provide a unifying mechanism. ATX transcripts and LPA receptor type 1 (LPA1) protein are elevated in HCC compared with normal tissues. Silencing or pharmacological inhibition of LPA1 significantly attenuated LPA-induced MMP-9 expression and HCC cell invasion. Further, reducing MMP-9 activity or expression significantly inhibits LPA-induced HCC cell invasion, demonstrating that MMP-9 is downstream of LPA1. Inhibition of phosphoinositide-3 kinase (PI3K) signaling or dominant-negative mutants of protein kinase Cδ and p38 mitogen-activated protein kinase (MAPK) abrogated LPA-induced MMP-9 expression and subsequent invasion. We thus demonstrate a mechanistic cascade of ATX-producing LPA with LPA activating LPA1 and inducing MMP-9 through coordinate activation of the PI3K and the p38 MPAK signaling cascades, providing novel biomarkers and potential therapeutic targets for HCC.

Telomere capture as a frequent mechanism for stabilization of the terminal chromosomal deletion associated with inverted duplication

We report 4 interstitial inverted duplications with associated terminal deletions (inv dup del) involving the short arms of chromosomes 5 and 8, and the long arm of chromosome 13 by microarray-based comparative genomic hybridization (aCGH) combined with chromosome banding (GTG banding) and fluorescence in situ hybridization (FISH) analyses. Formation of the intermediate dicentric chromosomes in 3 of them occurred through breakage-fusion-bridge cycle mechanism (U-type exchange mechanism) and in the fourth one it occurred through the mediation of the inverted low-copy repeats on chromosome 8p23.1. Two of these 4 inv dup del were confirmed and a third one was suspected to be associated with telomere capture for the healing of the terminal deletions. These findings indicate that a telomere capture mechanism is frequently used for stabilizing the broken chromosome ends in this type of genomic rearrangements. In addition, the inv dup del(13) represents the first observation of inv dup del on chromosome 13 in humans, the inv dup del(5) represents the first observation of inv dup del(5p) with an associated telomere capture, and unique features of the remaining two inv dup del(8p) were also discussed.

Accelerated thymocyte maturation in IL-12Rβ2-deficient mice contributes to increased susceptibility to autoimmune inflammatory demyelination

IL-12Rβ2(-/-) mice, which are unresponsive to IL-12, develop severe experimental autoimmune encephalomyelitis (EAE). The mechanisms for enhanced autoimmunity are incompletely understood. We report that in IL-12Rβ2(-/-) mice, thymocytes undergo markedly accelerated maturation. This occurs at the transition from a double positive (DP) to a single positive (SP) phenotype, resulting in higher numbers of CD4 and CD8 SP cells, and to a lesser extent at the transition from double negative (DN) to DP cells. Accelerated maturation is observed in mice injected with anti-CD3 to mimic pre-T-cell receptor stimulation, and also in mice immunized with myelin oligodendrocyte glycoprotein (MOG) peptide to induce EAE.

Comparison of Bayesian network and support vector machine models for two-year survival prediction in lung cancer patients treated with radiotherapy

PURPOSE

Classic statistical and machine learning models such as support vector machines (SVMs) can be used to predict cancer outcome, but often only perform well if all the input variables are known, which is unlikely in the medical domain. Bayesian network (BN) models have a natural ability to reason under uncertainty and might handle missing data better. In this study, the authors hypothesize that a BN model can predict two-year survival in non-small cell lung cancer (NSCLC) patients as accurately as SVM, but will predict survival more accurately when data are missing.

METHODS

A BN and SVM model were trained on 322 inoperable NSCLC patients treated with radiotherapy from Maastricht and validated in three independent data sets of 35, 47, and 33 patients from Ghent, Leuven, and Toronto. Missing variables occurred in the data set with only 37, 28, and 24 patients having a complete data set.

RESULTS

The BN model structure and parameter learning identified gross tumor volume size, performance status, and number of positive lymph nodes on a PET as prognostic factors for two-year survival. When validated in the full validation set of Ghent, Leuven, and Toronto, the BN model had an AUC of 0.77, 0.72, and 0.70, respectively. A SVM model based on the same variables had an overall worse performance (AUC 0.71, 0.68, and 0.69) especially in the Ghent set, which had the highest percentage of missing the important GTV size data. When only patients with complete data sets were considered, the BN and SVM model performed more alike.

CONCLUSIONS

Within the limitations of this study, the hypothesis is supported that BN models are better at handling missing data than SVM models and are therefore more suitable for the medical domain. Future works have to focus on improving the BN performance by including more patients, more variables, and more diversity.

Risks and causes of musculoskeletal injuries among health care workers

BACKGROUND

Musculoskeletal injuries (MSIs) persist as the leading category of occupational injury in health care. Limited evidence exists regarding MSIs for occupations other than direct patient care providers. An evaluation of the risks, causes and activities associated with MSIs that includes non-patient care health care occupations is warranted.

AIMS

To examine the risks and causes of time-loss MSIs for all occupations in health care.

METHODS

Workers employed by a health region in British Columbia were followed from April 2007 to March 2008 using payroll data; injuries were followed using an incidence surveillance database. Frequency and rates were calculated for all occupational injuries and MSIs and relative risks (RRs) were computed using Poisson regression. Causes and occupational activities leading to MSIs were tabulated for direct care occupations and non-patient care occupations.

RESULTS

A total of 944 injuries resulting in time-loss from work were reported by 23 742 workers. Overall, 83% injuries were musculoskeletal. The two occupations showing highest RR of MSIs relative to registered nurses were facility support service workers [RR = 3.16 (2.38-4.18), respectively] and care aides [RR=3.76 (3.09-4.59)]. For direct patient care occupations, the leading causes of MSIs were awkward posture (25%) and force (23%); for non-patient care occupations were force (25%) and slip/fall (24%). Patient handling activities accounted for 60% of all MSIs for direct care occupations. For non-patient care occupations, 55% of MSIs were due to material/equipment handling activities.

CONCLUSIONS

Prevention efforts for MSIs should be directed to non-patient care occupations as well and consider their occupation-specific causes and activities.

Enumeration of Vibrio parahaemolyticus in oyster tissues following artificial contamination and depuration

AIMS

To evaluate enumeration of Vibrio parahaemolyticus in oyster tissues following artificial contamination and depuration.

METHODS AND RESULTS

After inoculating with V. parahaemolyticus (ATCC 17802) and incubating for 24 h, the contaminated oysters were depurated with artificial seawater for 14 days. At each step, the tissue homogenate supernatants of oysters were spread-plated onto thiosulfate-citrate-bile salt-sucrose agar, followed by colony confirmation by the polymerase chain reaction. The pathogen was detected in the gills, digestive glands (including stomach, digestive ducts and digestive diverticula), adductor muscle and mantle cilia. After a 48-h depuration period at 17-19 degrees C, the retention rate of V. parahaemolyticus in the gills (28.1%) and digestive glands (13.5%) was higher than that in adductor muscle and mantle cilia (1.4 and 2.4%, respectively).

CONCLUSIONS

The population of V. parahaemolyticus in the digestive glands was the highest among all tissues tested, followed by the gills. The data indicate that digestive glands and gills are good sample candidates for direct monitoring of V. parahaemolyticus contamination in oysters.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on the dynamics of V. parahaemolyticus in various oyster tissues following artificial contamination and depuration. This study provides information to help in monitoring for V. parahaemolyticus in commercial oysters.

Inhibition spectrum studies of microthecin and other anhydrofructose derivatives using selected strains of Gram-positive and -negative bacteria, yeasts and moulds, and investigation of the cytotoxicity of microthecin to malignant blood cell lines

AIMS

To prepare 1,5-anhydro-d-fructose (AF) derivatives, test their microbial inhibition spectrum, and to further examine the most effective AF derivative against Pseudomonas aeruginosa and malignant blood cell lines.

METHODS AND RESULTS

Microthecin and nine other AF derivatives were synthesized from AF. The 10 compounds were tested in vitro against Gram-positive (GP) and Gram-negative (GN) bacteria, yeasts and moulds using a well diffusion method and in a Bioscreen growth analyser. Of the test compounds, microthecin exhibited the most significant antibacterial activity at 100-2000 ppm against both GP and GN bacteria, including Ps. aeruginosa. Further tests with three malignant blood cell lines (Mutu, Ramos, Raji) and one normal cell line indicated that microthecin was a cell toxin, with a cell mortality >85% at 50 ppm. The other nine AF derivatives demonstrated low or no antimicrobial activity.

CONCLUSIONS

Microthecin was active 100-2000 ppm against GP and GN bacteria including Ps. aeruginosa, but was inactive against yeasts and moulds. Microthecin was also a cytotoxin to some mammalian cell lines.

SIGNIFICANCE AND IMPACT OF THE STUDY

Microthecin might have potential for development as a novel drug against Ps. aeruginosa and to target cancer cells. It might also be developed as a food processing aid to control bacterial growth.

Morphological analysis of the lung of neonatal yak

Although yaks play an important role as companion or pack and draught animals on Chinese plateaus in alpine and sub-alpine regions, morphological studies and anatomical data on the lung of yak are sparse. To provide anatomical descriptions and morphometric data, 10 one-day-old yaks were examined by means of dissection, light and electron microscopy. The measurements of lung were made on dissected specimens and histological sections. Unequal dichotomous branching was demonstrated in the dissected tracheobronchial tree. The diameters of bronchial airways and height of epithelium were measured, and showed that the variation of diameters in airways was always greater than that of height of epithelium. In addition, the thickness of muscularis, cartilage and adventitia was examined, as well as the number of goblet and Clara cells in airways. Ultrastructural studies showed that the surface epithelium was mainly composed of goblet, ciliated, Clara and basal cells, similar to that in other domestic animals. Under electron microscope, two distinctive types of ciliated cells could be seen in the tracheobronchial epithelium. The first type contained some mitochondria, distended smooth endoplasmic reticulum (SER), little rough endoplasmic reticulum (RER) and numerous vacuoles in electron-lucent cytoplasm. The second type had dense cytoplasm with abundant mitochondria, RER and no vacuoles. Both types were rich of glycogen granules. The goblet cells in neonatal yak lung had the following characteristic features: dentate nucleus in dense cytoplasm, with stacks of RER and numerous dense membrane-bounded mucous droplets, which were round or oval, often with an electron-lucent core. The droplets were not confluent. Glycogen granules were numerous, and Golgi complex was occasionally present. Clara cells were dome-shaped and usually protruded into the airway lumen. Large amounts of SER and many secretory droplets were found within the cytoplasm. Several typical 'clefts' were also found in the cytoplasm.

TAK-285, a Novel HER2/EGFR Inhibitor, Penetrates the CNS in Rats with an Intact Blood Brain Barrier (BBB)

Background: Approximately one third of patients with HER2-overexpressing (HER2+) metastatic breast cancer develop brain metastases. Treatment options for patients whose brain metastases have progressed after radiotherapy are urgently needed. The currently approved HER2-targeted therapies, trastuzumab and lapatinib, have generally shown limited activity against brain metastases, likely due to the limited brain penetration of these drugs. Brain penetration is mediated by multiple factors including drug permeability, tissue binding, and the expression of efflux transporters (P-gp and BCRP) and their interactions with the drug. TAK-285 is a novel, orally active, dual HER2/EGFR inhibitor currently under clinical development. In this nonclinical work, we evaluated the permeability, interactions with efflux transporters, and brain penetration of TAK-285, along with lapatinib and neratinib, using in vitro and animal models.Material and Methods: The first study evaluated the permeability of TAK-285, lapatinib, and neratinib and their interactions with efflux transporters using the Caco-2 cell monolayer system in the absence or presence of efflux pump inhibitors. The second study evaluated brain penetration of TAK-285, lapatinib and neratinib after a single oral administration in rats with an intact BBB.Results: In the Caco-2 cell model, TAK-285 showed high permeability with an efflux ratio of 1.7, indicating it is not a substrate for efflux pumps. The efflux pump inhibitors LY335979 (an inhibitor of P-gp), Ko143 (an inhibitor of BCRP), and GF120918 (an inhibitor of BCRP and P-gp) had no marked effect on the efflux ratio of TAK-285, further confirming that TAK-285 is not a substrate for P-gp and BCRP. Lapatinib and neratinib showed low to medium permeability and appeared to be substrates for P-gp/BCRP in this testing system. In the rat brain penetration study, the brain-to-plasma AUC ratio for total (free and bound) TAK-285, lapatinib, and neratinib was 0.202, 0.0243, and 0.0263, respectively.Discussion: These nonclinical studies showed that, unlike lapatinib and neratinib, TAK-285 is not a substrate for the efflux transporters, P-gp and BCRP. Based on published information, all of the approved receptor tyrosine kinase inhibitors are substrates for efflux transporters. Additionally, in rats with an intact BBB, the brain-to-plasma AUC ratio for TAK-285 was substantially higher than that of lapatinib and neratinib. The AUC ratios observed in this study for lapatinib and neratinib are similar to the proportion of blood volume in the rat brain (ie, outside the CNS) relative to the total rat brain volume. This suggests the actual brain-to-plasma AUC ratio for TAK-285 in rats may be much greater than 8-fold of that of lapatinib and neratinib calculated based on these measured AUC ratios. Consequently, TAK-285 may have a unique role in the treatment of brain lesions in patients with HER2- or EGFR-dependent tumors. Furthermore, TAK-285 may not be subject to drug resistance conferred by efflux transporters.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5098.

A miniature confocal Raman probe for endoscopic use

Raman spectroscopy is a powerful tool for studying biochemical changes in the human body. We describe a miniature, confocal fibre optic probe intended to fit within the instrument channel of a standard medical endoscope. This probe has been optimized for the study of the carcinogenesis process of oesophageal malignancy. The optical design and fabrication of this probe is described including the anisotropic wet etching technique used to make silicon motherboards and jigs. Example spectra of PTFE reference samples are shown. Spectra with acquisition times as low as 2 s from resected oesophageal tissue are presented showing identifiable biochemical changes from various pathologies.

Farm work-related injury among middle school students in rural China

Farm work-related injuries are considered an important issue facing rural area adolescents. However, little research has been done in developing countries, including China. This study evaluated agricultural work-related injuries among Chinese middle school adolescents, focusing on the potential association between farm work hours, sleep patterns, school-related stress, and farm work-related injuries. This cross-sectional study surveyed 1,551 middle school students in Hunan Province who reported working on farms. The surveys assessed their involvement in farm work, sleep patterns, school activities, and farm work-related injuries during a three-month recall period. The cumulative incidence of farm work-related injury was 15.6% among the 1187 students who reported working on a farm. Average days per month farming, number of pesticide applications per month, sleep disturbances, and school-related stress were significantly associated with farm work-related injuries (p < 0.05). Multivariable logistic regression analysis revealed that after adjusting for possible confounding effects of age, gender, and farm work days per month, sleep disturbance (less than 7 hours of sleep: OR = 2.36, 95% CI = 1.07-5.22; awakening at night and having trouble falling back to sleep: OR = 2.70, 95% CI = 1.36-5.37; having nightmares: OR = 2.24, 95% CI = 1.18-4.24) and school-related stress (difficult homework: OR = 2.45, 95% CI = 1.21-4.99; extra homework assigned often by parents: OR = 3.62, 95% CI = 1.88-6.97; and scolded/chastised by parents for poor school performance: OR = 2.53, 95% CI = 1.75-3.65) were statistically significant risk factors for farm work-related injuries (p < 0.05).

Reversible Cerebral Vasoconstriction Syndrome with Posterior Leucoencephalopathy after Oral Contraceptive Pills

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden-onset recurrent ‘thunderclap’ headaches with reversible multifocal narrowing of the cerebral arteries, often associated with focal neurological deficits from ischaemic or haemorrhagic stroke. It has been associated with exposure to vasoconstrictive drugs, pregnancy, migraine, and a variety of other conditions. Whereas the pathophysiology of RCVS remains unclear, changes in the levels of female hormones are considered important because RCVS predominantly affects women and is frequently associated with pregnancy. We report a patient with angiographically confirmed RCVS whose MRI showed reversible brain oedema, suggesting an overlap between RCVS and the reversible posterior leucoencephalopathy syndrome. The only identified risk factor was oral contraceptive pills started 1 month prior to onset, supporting a role for female reproductive hormones in precipitating this overlap syndrome.