Introduction Aberrant activation of Wnt/beta-catenin signaling plays an important role in the pathogenesis of breast cancer. DACT1 (Dapper/Frodo) has been identified as involved in antagonizing ...Wnt/beta-catenin signaling through interacting with Dishevelled (Dvl), a central mediator of Wnt signaling, whereas its role in breast tumorigenesis remains unclear. Methods We examined DACT1 expression in breast cancer cell lines and primary tumors with semiquantitative or quantitative RT-PCR and immunochemistry, and further evaluated the promoter methylation of DACT1 with methylation-specific PCR (MSP). We also explored the tumor-suppressive functions of DACT1 in vivo and in vitro, and its related mechanism in breast cancer. Results We identified DACT1 as a methylated target in our breast cancer epigenome study. Here, we further investigated DACT1 expression in multiple breast cell lines and primary tumors, and further studied its function and molecular mechanisms. We found that DACT1 expression was silenced in eight (88.9%) of nine breast cancer cell lines, and its protein levels were obviously reduced in breast tumors compared with paired surgical-margin tissues. Promoter CpG methylation of DACT1 was detected in five (55.6%) of nine breast cancer cell lines and 40 (29.9%) of 134 primary tumors, but not in surgical-margin tissues and normal breast tissues. Demethylation treatment of breast cancer cell lines restored DACT1 expression along with promoter demethylation, suggesting that an epigenetic mechanism mediates DACT1 silencing in breast cancer. Functional assays showed that ectopic expression of DACT1 could inhibit breast tumor cell proliferation in vivo and in vitro through inducing apoptosis, and further suppress tumor cell migration through antagonizing the Wnt/beta-catenin signaling pathway. Conclusions Our study demonstrates that DACT1 could function as a tumor suppressor but was frequently downregulated in breast cancer.
In order to improve the quality and accuracy of blanking workpiece, reasonable measures have been proposed during the production process. Firstly, the quality precision of blanking workpiece has been ...classified into three grades, corresponding to each type of dimensional accuracy, reasonal range of blanking clearance has been selected. Then the relationship of blanking clearance size with blanking quality has also been analyzed, and the affection of blanking clearances to dimensional accuracy has also been analyzed.At last, the method to improve the workpiece quality has been proposed, and the measure has been put forward to solve problems of quality and accuracy. The results refer useful references to improve the quality of stampings.
Strongly correlated materials often exhibit an electronic phase separation (EPS) phenomena whose domain pattern is random in nature. The ability to control the spatial arrangement of the electronic ...phases at microscopic scales is highly desirable for tailoring their macroscopic properties and/or designing novel electronic devices. Here we report the formation of EPS nanoscale network in a mono-atomically stacked LaMnO3/CaMnO3/PrMnO3 superlattice grown on SrTiO3 (STO) (001) substrate, which is known to have an antiferromagnetic (AFM) insulating ground state. The EPS nano-network is a consequence of an internal strain relaxation triggered by the structural domain formation of the underlying STO substrate at low temperatures. The same nanoscale network pattern can be reproduced upon temperature cycling allowing us to employ different local imaging techniques to directly compare the magnetic and transport state of a single EPS domain. Our results confirm the one-to-one correspondence between ferromagnetic (AFM) to metallic (insulating) state in manganite. It also represents a significant step in a paradigm shift from passively characterizing EPS in strongly correlated systems to actively engaging in its manipulation.
To investigate the relationship between tinnitus and glucose metabolism in auditory cortex and whether positron emission tomography (PET) can be an objective tool in measuring tinnitus.
Eleven ...right-handed patients with severe tinnitus and ten right-handed control subjects participated in the 18F-FDG/PET study. Analysis with regions of interests was used to calculate asymmetry indices according to the formula: (L-R) x 100/(L + R) divided by 2.
Glucose metabolism in the auditory cortex of tinnitus patients was asymmetric between the left and right auditory cortices, with that of the left being much higher than that of the right. The asymmetry indices of tinnitus patients was significantly higher than that of the control group (unpaired t test, P < 0.001). This revealed that the increased metabolic activity was present in the predominant left hemisphere with a significant focus on the superior and transverse temporal gyri (Brodmann areas 41 and 42, respectively corresponding to primary and secondary auditory cortex), and the results were independent of the subjective localization of the tinnitus sensation.
It is suggested that the increased metabolism in the left auditory cortex is related to the tinnitus sensation. PET is capable of providing objective evidence for tinnitus and may be used as a potential tool in measuring tinnitus.
The purpose of this study was to investigate the weight-control behavior of obese children, to understand parents’ supervision and to explore related factors that influenced the weight-control ...behavior. A structured questionnaire was employed in this study. A random sample of 287 children and their parents was recruited from six elementary schools in Shihlin and Peitou districts of Taipei City. Criteria employed for recruitment of subjects were: third and fourth grade in elementary schools, and weight-for-length index ≧ 1.2. Results: Fifty-six percent of the obese children were mildly obese and eleven percent were severely obese. Ninety-seven percent of the subjects adopted weight-control behavior, the most frequent one being avoiding fried food. The exercise frequency and time duration consistency were generally insufficient. Twenty-seven percent of the obese children were not in the habit of exercising. Factors that influenced the execution of weight-control behavior by the obese children included obesity l
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