In cancer cells, loss of E-cadherin gene expression caused dysfunction of the cell-cell junction system, triggering cancer invasion and metastasis. Therefore, E-cadherin is an important tumor-suppressor gene. To understand how E-cadherin gene expression is regulated in cancer cells, we have used E-cadherin-positive and -negative expressing cells to find out the possible up-or downregulating transcription factors in human E-cadherin regulatory sequences. Functional analysis of human E-cadherin regulatory sequences constructs indicated that AML1, Sp1, and p300 may play important roles in promoting E-cadherin expression. In addition, we found there are four HNF3-binding sites in human E-cadherin regulatory sequences. The exogenous HNF3 can enhance the E-cadherin promoter activity in metastatic breast cancer cells and the metastatic breast cancer cells stably transfected with HNF3 showed re-expression of E-cadherin. The HNF3 stable transfectants changed from mesenchymal-like into epithelial morphology. The transwell assays showed the re-expressed E-cadherin reduced cell motility of metastatic breast cancer cells. These results suggested HNF3 may play important roles in the upregulation of the E-cadherin promoter, with the consequent re-expression of E-cadherin, thus reducing the metastatic potential of breast cancer cells. These findings suggested HNF3 plays important roles in the upregulation of the E-cadherin gene and may be able to reduce the motility of metastatic breast cancer cells.

In this paper, performance degradation of RFID system due to curving in tag antenna is investigated through radar cross section (RCS) analysis. While the limitation in the read range of passive RFID system is mainly dominated by the received RF power from reader on the tag side, RCS analysis of tag antenna provides a direct and effective way for the evaluation of overall system performance. For simplicity consideration without losing generality, a simple half-wavelength planar dipole at 900MHz is used for RCS analysis under various curving conditions. Results show that the read range can be degraded significantly due to curving.

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A septum polarizer influenced by inserting short stubs inside the waveguide is studied. Several configurations of stub insertion are investigated to exhibit their physical behaviors. Numerical results show that proper stub insertions may provide additional freedoms to optimally design the polarizer with a better return loss and a flexible phase tuning, which is particularly useful to compensate the deficiency of an imperfect horn antenna to radiate good circularly polarized fields. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 269–273, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23982