Objective To investigate the effect of small interfering RNA (siRNA) interference in the expression of epidermal growth factor receptor (EGFR) on the radiosensitivity of esophageal squamous carcinoma (Eca-109) and esophageal adenocarcinoma (OE-19) cell lines.Methods Human Eca-109 and OE-19 cell lines were selected as study subjects.Various EGFR-siRNA and negative siRNA were synthesized chemically through lipofection.Reverse transcription-polymerase chain reaction and Western blot were applied to measure the expression of EGFR before and after transfection,and the CCK8 assay was applied to analyze the influence of transfection on cell proliferation.Blank control groups of Eca-109 and OE-19 cells (O1 and O2 groups),simple irradiation groups (R1 and R2 groups),and EGFR-siRNA irradiation groups (E-R1 and E-R2 groups) were set,and the doses for single irradiation were 0,2,4,6,and 8 Gy.The colony-forming assay was applied to calculate survival fraction (SF) and sensitization enhancement ratio (SERD0 ratio),and flow cytometry was applied to evaluate the influence of EGFR-siRNA combined with radiotherapy on cell cycle distribution and apoptosis rate,and the dose for single irradiation was 6 Gy.Results The expression of EGFR in both cell lines was significantly down-regulated by EGFR-siRNA,and the inhibition rate of cell proliferation by transfection was＜5％ (4.9％ and 4.5％,respectively).The results of colony-forming assay showed that the cells in the E-R1 and E-R2 groups had a lower SF than those in the O1 and O2 groups,with an SERD0ratio of 1.40 and 1.01,respectively.The results from flow cytometry showed that compared with the E-R2 group,the E-R1 group had a higher proportion of cells in G2/M phase and a lower proportion of cells in S phase after irradiation (P=0.016 and 0.028),as well as a higher apoptosis rate (P=0.007).Conclusions Compared with the cell line OE-19,the cell line Eca-109 has a significantly increased radiosensitivity when treated with siRNA interference in EGFR expression.

OBJECTIVESTo identify the cortical areas engaged during Chinese word processing using functional magnetic resonance imaging (fMRI) and to examine the reliability and reproducibility of fMRI for localization of functional areas in the human brain.

METHODSFMRI data were collected on 8 young, right-handed, native Chinese speakers during performance of Chinese synonym and homophone judgment tasks on two different clinical MRI systems (1.5 T GE Signa Horizon and 1.5 T Siemens Vision). A cross correlation analysis was used to statistically generate the activation map.

RESULTSBroca's area, Wernicke's area, bilateral extrastriate, and ventral temporal cortex were significantly activated during both the synonym and homophone activities. There was essentially no difference between results acquired on two different MRI systems.

CONCLUSIONSFMRI can be used for localizing cortical areas critical to Chinese language processing in the human brain. The results are reliable and well reproducible across different clinical MRI systems.

Adult ; Cerebral Cortex ; physiology ; Female ; Humans ; Language Tests ; Magnetic Resonance Imaging ; Male ; Reproducibility of Results