Objective To investigate the effect of overexpression of miR-30b on the proliferation,cell cycle,apoptosis and invasion of gastric cancer cell line SGC-7901 and AGS,and the inhibitory effect on the tumor formation in vivo.Methods SGC-7901 and AGS cells were transfected with miR-30b mimics and miR-control,and qRT-PCR was used to detect the expression levels of miR-30b.Western blot assay was used to detect the expression of eIFSA2 protein.CCK-8 assay was used to measure the cell proliferation.Flow cytometry was used to analyze cell cycle and apoptosis.Transwell assay was used to detect cell invasion.In addition,the SGC-7901 and AGS cells transfected with miR-30b mimics and miR-control were injected into nude mice to observe the tumor formation and the expression of eIFSA2 protein in vivo.Results Results of qRT-PCR showed that the relative expression of miR-30b was significantly higher than that of miR-control group (P ＜ 0.05).Western blot assay showed that the expression of eIF5A2 protein was decreased in miR-30b mimics group.CCK-8 assay showed that cell proliferation was inhibited in miR-30b mimics group.The result of flow cytometry showed that the cell cycle decreased and the apoptosis increased in miR-30b group.Transwell assay showed that the cell invasion was significantly lower in miR-30b group than that of control group (P ＜ 0.05).Overexpression of miR-30b inhibited the formation of tumor and decreased the expression of eIF5A2 protein in vivo.Conclusion Overexpression of miR-30b inhibits the proliferation,invasion and tumor formation of gastric cancer cells,and reduces the expression of eIF5A2 protein,which provides a potential target for gastric cancer treatment.

Objective:To investigate the accuracy of magnetic resonance imaging (MRI) cine sequences in determining the range of tumor motion in radiotherapy, providing a basis for the precise delineation of the target volume in motion for radiation therapy.Methods:A modified chest motion phantom was placed in a MRI scanner, and a water-filled sphere was used to simulate a tumor. True fast imaging with steady precession (TrueFISP) MRI cine sequences from Siemens were used to capture the two-dimensional motion images of the simulated tumor. The phantom experiments were divided into three modes: head-foot motion mode, rotation motion mode, and actual respiratory waveform mode. In the head-foot motion mode, respiratory motion period (3, 4, 5, 6, 7 and 8 s), amplitude (5, 10 and 15 mm), and respiratory waveform of the simulated tumor (sin and cos4) were set, resulting in a total of 36 motion combinations. In the rotation motion mode, a cos4 waveform was used for respiration, with respiratory periods of 3, 4, 5, 6, 7 and 8 s, head-foot motion set amplitudes of 5, 10 and 15 mm, and anterior-posterior (AP) and left-right (LR) motion set amplitudes in three combinations ([2.5, 2.5] mm, [2.5, 5.0] mm, [5.0, 5.0] mm), resulting in a total of 54 motion combinations. In the actual respiratory waveform mode, respiratory waveforms of 5 randomly selected patients from Affiliated Cancer Hospital of Zhengzhou University were obtained. Under each motion combination, TrueFISP cine images (30 frames, with an acquisition time of 11 s per frame) were obtained. The code was used to automatically identify the two-dimensional coordinates of the center of the simulated tumor in each image, and sin and cos4 functions were separately employed to fit the tumor position in the motion direction, thereby obtaining the fitted motion period and amplitude. The difference between the maximum and minimum values of the tumor's center coordinates in the head-to-foot direction is taken as the range of movement, referred to as the calculated amplitude. For the actual respiratory waveform, the distance between the measured maximum and minimum positions is used to calculate the amplitude.Results:In the head-foot motion mode, the fitted amplitudes of both sin and cos4 waveforms deviated from the set amplitudes by 0-0.51 mm, with relative deviations of 0%-4.2%. The deviation range between the calculated amplitudes and the set amplitudes of the two waveforms were 0.08-0.94 mm, with relative deviations of 1.1%-6.3%. In the rotation motion mode, the fitted amplitudes deviated from the set amplitudes by 0-0.61 mm, with relative deviations of 0%-6.2%. And the deviation range between the calculated amplitudes and the set amplitudes were 0.16-0.94 mm, with relative deviations of 0%-6.3%. In the actual respiratory waveform motion mode, the deviation range between the calculated amplitudes and the set amplitudes were 0.10-0.48 mm, with relative deviations of 2.2%-8.6%.Conclusion:TrueFISP cine sequences show minimal deviations in determining the range of tumor head-foot motion and effectively captures the tumor's movement state, thereby providing important support for the precise definition of the tumor movement target area during radiotherapy .