Objective To investigate the effects of blocking gastrin receptor on the proliferation,apoptosis and expression of key proteins in the related pathway in gastric cancer cell lines.Methods In the experimental group,the gastric cancer cell lines SGC-7901 and AGS cells were treated with 5 mmol/L proglumide,a kind of a gastrin receptor antagonist.And the normal cultured gastric cancer cells SGC-7901 and AGS were used in control group.The growth of each group was detected by MTT assay;the cell growth curve was drawn by flow cytometry;the cell cycle of each group was detected by flow cytometry.Annexin V-FITC/PI double staining was used to detect the cell growth of apoptosis.The relative mRNA expression of β-catenin,nuclear factor-P65,mammalian target of rapamycin and glycogen synthase kinase 3 beta in Wnt,NF-κB and PI3K-AKT-MTOR pathways were detected by RT-qPCR.The expression of β-catenin protein was detected by Western blotting.Results After treatment with proglumide,the growth of the cells in the experimental group was lower than that in the control group;and the proportion of S phase cells in the cell cycle was also lower than that in the control group,but the proportion of cells in G0/G1 phase was higher than that in the control group(P<0.05).The percentage of apoptotic cells was also increased after treatment with proglumide(P<0.05).Furthermore,proglumide treatment significantly reduced the expression of β-catenin at both mRNA and protein levels(P<0.05).Conclusion Blocking gastrin receptor can down-regulate the expression of β-catenin,inhibit the cell proliferation and promote the cell apoptosis in gastric cancer cells.

Objective： ：To study the effect of silencing DKK1 (Dickkopf1) gene on the proliferation, cell cycle and apoptosis of gastric cancer AGS cells and the action mechanism. Methods： ：The DKK1-shRNA vector was constructed and transfected into AGS cells. The stably transfected cell lines were screened. The total protein and RNAof the transfected cells were extracted and the mRNAand protein expressions of DKK1 were detected by qPCR and WB, respectively. The experiment was divided into blank control group (Control), negative control group (shNC) and DKK1 silence group (DKK1-shRNA). CCK8 assay was used to detect the proliferation ofAGS cells of each group cultured for 0, 24, 48, 72, 96, 120 and 144 h, and flow cytometry was used to analyze the cell cycle and apoptosis in each group. The relationship between DKK1 and clinicopathological features of gastric cancer was analyzed after searching HPA database. Results：The gastric cancer AGS cells with stable DKK1 gene knockdown was successfully established, and it was confirmed that the mRNA and proteinexpressions of DKK1 in DKK1-shRNA group decreased by 72% and 47%, respectively, compared to shNC group (all P<0.05). The cell proliferation curve showed that, the cell proliferation in DKKl-shRNAgroup significantly decreased after 72 hour of culture compared with that in control and shNC groups (P<0.05). The cell number of S phase decreased from 32.06% to 25.87%, while the number of G2/M phase increased from 8.49% to 21.26% compared with shNC group (all P<0.05). The number of apoptotic cells also statistically increased from 10.34% to 20.65% (all P<0.05). The data of HPAdatabase showed that DKK1 mRNAlevel in gastric cancer tissues was significantly higher than that in normal tissues, and the high expression of DKK1 mRNAwas negatively correlat ed with the survival rate of gastric cancer patients. Conclusion: : Silencing DKK1 gene can inhibit the proliferation of gastric cancer cells, arrest cells in G2/M phase and promote cell apoptosis. DKK1 plays a pro-carcinogenic effect in gastric cancer.

Circadian rhythm is a phenomenon of diurnal changes in life activities formed by a transcription-translation feedback loop of biological clock genes affected by external environmental conditions. The circadian rhythm system controls almost all physiological processes in the organism, and these processes will change as the external environment changes. Previous studies have shown that the hypothalamic-pituitary-thyroid axis in mammals is regulated by the central diurnal pacemaker of the suprachiasmatic nucleus of the hypothalamus, so part of the thyroid function is controlled by the biological clock, and the secretion of thyroid hormones in blood can present a circadian rhythm. However, the molecular mechanism of the biological clock's regulatory effect on thyroid is still unclear. Whether circadian rhythm interference is related to the disorder of thyroid function or the occurrence of thyroid diseases is worthy of attention. This paper focused on the research progress of biological clock, circadian rhythm, and thyroid function, specifically the characteristics of circadian rhythm of thyroid physiological function and the effects of sleep deprivation, light at night, and night shift work on thyroid function, elaborated the relationships of circadian rhythm disorder with thyroid function and thyroid diseases represented by thyroid malignant tumors. The review summarized that circadian rhythm disorder may disrupt the rhythmic secretion of thyroid hormones, but no clear conclusion is reached yet on any effect on thyroid diseases, especially thyroid malignant tumors, so it is necessary to further strengthen the relevant epidemiological and molecular mechanism research.