A stable explant culture of HER2/neu invasive carcinoma supported by alpha-Smooth Muscle Actin expressing stromal cells to evaluate therapeutic agents

<p>Abstract</p> <p>Background</p> <p>To gain a better understanding of the effects of therapeutic agents on the tumor microenvironment in invasive cancers, we developed a co-culture model from an invasive lobular carcinoma. Tumor cells expressing HER2/neu organize in nests surrounded by alpha-Smooth Muscle Actin (α-SMA) expressing tumor stroma to resemble the morphology of an invading tumor. This co-culture, Mammary Adenocarcinoma Model (MAM-1) maintains a 1:1 ratio of HER2/neu positive tumor cells to α-SMA-reactive stromal cells and renews this configuration for over 20 passages in vitro.</p> <p>Methods</p> <p>We characterized the cellular elements of the MAM-1 model by microarray analysis, and immunocytochemistry. We developed flow cytometric assays to evaluate the relative responses of the tumor and stroma to the tyrosine kinase inhibitor, Iressa.</p> <p>Results</p> <p>The MAM-1 gene expression profile contains clusters that represent the ErbB-2 breast cancer signature and stroma-specific clusters associated with invasive breast cancers. The stability of this model and the ability to antigenically label the tumor and stromal fractions allowed us to determine the specificity of Iressa, a receptor tyrosine kinase inhibitor, for targeting the tumor cell population. Treatment resulted in a selective dose-dependent reduction in phospho-pMEK1/2 and pp44/42MAPK in tumor cells. Within 24 h the tumor cell fraction was reduced 1.9-fold while the stromal cell fraction increased >3-fold, consistent with specific reductions in phospho-pp44/42 MAPK, MEK1/2 and PCNA in tumor cells and reciprocal increases in the stromal cells. Erosion of the tumor cell nests and augmented growth of the stromal cells resembled a fibrotic response.</p> <p>Conclusion</p> <p>This model demonstrates the specificity of Iressa for HER2/neu expressing tumor cells versus the tumor associated myofibroblasts and is appropriate for delineating effects of therapy on signal transduction in the breast tumor microenvironment and improving strategies that can dually or differentially target the tumor and stromal elements in the microenvironment.</p

Expression and prognostic significance of THBS1, Cyr61 and CTGF in esophageal squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Thrombospondin1 (THBS1), cystene-rich protein 61 (Cyr61) and connective tissue growth factor (CTGF) are all involved in the transforming growth factor-beta (TGF-β) signal pathway, which plays an important role in the tumorigenesis. The purpose of this study is to explore the expression and prognostic significance of these proteins in esophageal squamous cell carcinoma (ESCC).</p> <p>Methods</p> <p>We used immunohistochemistry and western blotting to examine the expression status of THBS1, Cyr61 and CTGF in ESCC. Correlations of THBS1, Cyr61 and CTGF over-expressions with various clinicopathologic factors were also determined by using the Chi-square test or Fisher's exact probability test. Survival analysis was assessed by the Kaplan-Meier analysis and the log-rank test. Relative risk was evaluated by the multivariate Cox proportional hazards model.</p> <p>Results</p> <p>THBS1, Cyr61 and CTGF were all over-expressed in ESCC. THBS1 over-expression was significantly associated with TNM stage (<it>P </it>= 0.029) and regional lymph node involvement (<it>P </it>= 0.026). Kaplan-Meier survival analysis showed that over-expression of THBS1, Cyr61 or CTGF was related to poor survival of ESCC patients (<it>P </it>= 0.042, <it>P </it>= 0.020, <it>P </it>= 0.018, respectively). Multivariate Cox analysis demonstrated that Cyr61 and CTGF were independent factors in prognosis of ESCC.</p> <p>Conclusion</p> <p>Cyr61, CTGF and THBS1 were all over-expressed in ESCC and might be new molecular markers to predict the prognosis of ESCC patients.</p

Genome-wide survey and analysis of microsatellites in nematodes, with a focus on the plant-parasitic species Meloidogyne incognita

<p>Abstract</p> <p>Background</p> <p>Microsatellites are the most popular source of molecular markers for studying population genetic variation in eukaryotes. However, few data are currently available about their genomic distribution and abundance across the phylum Nematoda. The recent completion of the genomes of several nematode species, including <it>Meloidogyne incognita</it>, a major agricultural pest worldwide, now opens the way for a comparative survey and analysis of microsatellites in these organisms.</p> <p>Results</p> <p>Using MsatFinder, the total numbers of 1-6 bp perfect microsatellites detected in the complete genomes of five nematode species (<it>Brugia malayi</it>, <it>Caenorhabditis elegans</it>, <it>M. hapla</it>, <it>M. incognita</it>, <it>Pristionchus pacificus</it>) ranged from 2,842 to 61,547, and covered from 0.09 to 1.20% of the nematode genomes. Under our search criteria, the most common repeat motifs for each length class varied according to the different nematode species considered, with no obvious relation to the AT-richness of their genomes. Overall, (AT)_<it>n</it>, (AG)_{<it>n </it>}and (CT)_{<it>n </it>}were the three most frequent dinucleotide microsatellite motifs found in the five genomes considered. Except for two motifs in <it>P. pacificus</it>, all the most frequent trinucleotide motifs were AT-rich, with (AAT)_{<it>n </it>}and (ATT)_{<it>n </it>}being the only common to the five nematode species. A particular attention was paid to the microsatellite content of the plant-parasitic species <it>M. incognita</it>. In this species, a repertoire of 4,880 microsatellite loci was identified, from which 2,183 appeared suitable to design markers for population genetic studies. Interestingly, 1,094 microsatellites were identified in 801 predicted protein-coding regions, 99% of them being trinucleotides. When compared against the InterPro domain database, 497 of these CDS were successfully annotated, and further assigned to Gene Ontology terms.</p> <p>Conclusions</p> <p>Contrasted patterns of microsatellite abundance and diversity were characterized in five nematode genomes, even in the case of two closely related <it>Meloidogyne </it>species. 2,245 di- to hexanucleotide loci were identified in the genome of <it>M. incognita</it>, providing adequate material for the future development of a wide range of microsatellite markers in this major plant parasite.</p

Impact of Aging on Distal Tibia Metaphysis Diameter

One of the many bone changes that occur with aging is “cortical drift”, the absorption and deposition of bone on the endosteal and periosteal side, respectively, which results in bone enlargement in some but not all metaphyses. The distal tibia is one of the most fractured sites in the body and where anatomically shaped implants are mostly used. The economic viability of these implants depends on the maintenance of bone contour throughout life. MRI sagittal ankle images from 422 patients aged 18 to 100 years were analyzed and total distal tibia diameter measured. No correlation was observed between the parameters age and distal tibia diameter (Pearson-0.099), or when individuals were separated by sex (Pearson-0.021 for men and 0.049 for women). When separated by age, patients younger and older than 60 years old had a similar average height (1.65 and 1.62 m, respectively, student’s t- test = 0). This is the first study to evaluate possible age-related distal tibia enlargement. Bone changes with age do not result in distal tibia enlargement and possibly the majority of anatomically shaped bone implants are suitable irrespective of age.</jats:p

Effective Brain Connectivity from Intracranial EEG Recordings: Identification of Epileptogenic Zone in Human Focal Epilepsies

In the context of focal and drug-resistant epilepsy, surgical resection of the epileptogenic zone (EZ) may be the only therapeutic option for reducing or suppressing seizures. The aim of epilepsy surgery is the exeresis of the EZ, which is assumed to be the cortical region responsible for the onset, early organization, and propagation of seizures. EZ represents the minimum amount of cortex that must be resected in order to achieve seizure freedom; therefore, the correct identification of its extent and organization is a crucial objective. Nevertheless, the rather high rate of failure in epilepsy surgery in extra-temporal epilepsies highlights that the precise identification of the EZ is still an unsolved problem and that more sophisticated methods of investigation are required. In many patients, intracranial stereo-EEG recordings still represent the gold standard for the epilepsy surgery work-up, and, over the last 10 years, considerable efforts have been made to develop advanced signal analysis techniques able to improve the identification of the EZ. Since it is widely assumed that epileptic phenomena are associated with abnormal changes in brain synchronization mechanisms, particular attention has been paid to those methods aimed at quantifying and characterizing the interactions and causal relationships of neuronal populations, and initial evidence has shown that this can be a suitable approach to localizing the EZ. The aim of this review is to provide an overview of the different intracranial EEG signal processing methods used to identify the EZ, with particular attention being given to the methods aimed at characterizing effective brain connectivity using intracranial EEG recordings. Then, we briefly present our studies of the connectivity pattern associated with a particular form of focal epilepsy (type II focal cortical dysplasia), based on multivariate autoregressive parametric models and measures derived from graph theory