miR-497 inhibits the growth and metastasis of SGC-7901 human gastric cancer anoikis resistant cells via blocking Wnt/β-catenin signaling pathway / 细胞与分子免疫学杂志

Objective To investigate the effects of microRNA497 (miR-497) on the metastasis of gastric cancer and its possible molecular mechanism. Methods SGC-7901 gastric cancer parent cells were cultured in an ultra-low adhesion environment, and the anoikis resistance model of SGC-7901 cells was created after re-adhesion. Clone formation assay, flow cytometry, TranswellTM test and scratch healing test were used to detect the differences of biological behavior compared with their parent cells. Fluorescence quantitative PCR was performed to detect the expression of miR-497. Western blot analysis was used to detect the changes of key proteins of Wnt/β-catenin signaling pathway and epithelial mesenchymal transformation (EMT) related proteins such as vimentin and E-cadherin. Parent cells and anoikis resistant SGC-7901 cells were transfected with miR-497 inhibitor or miR-497 mimic, and CCK-8 assay was used to detect the proliferation activity. TranswellTM invasion assay was performed to detect the invasion ability of cells. TranswellTM migration test and scratch healing assay was used to determine the migration ability. Western blot analysis was used to detect the expressions of Wnt1, β-catenin, vimentin and E-cadherin. By transfecting miR-497 mimic into the anoikis resistance SGC-7901 cells and inoculating them subcutaneously in nude mice, the changes in the volume and mass of tumor tissues were measured and recorded. Western blot analysis was used to determine the expressions of Wnt1, β-catenin, vimentin and E-cadherin of tumor tissues. Results Compared with the parent cells, the anoikis resistance SGC-7901 gastric cancer cells had faster proliferation rate, stronger colony formation, lower apoptosis rate, stronger invasion and migration ability. The expression of miR-497 was significantly decreased. After down-regulation of miR-497, the proliferation ability, invasion and migration ability were significantly enhanced. The expressions of Wnt1, β-catenin and vimentin increased significantly, while E-cadherin decreased notably. The results of up-regulation miR-497 were the opposite. The tumor growth rate, tumor volume and mass of miR-497 overexpression group were significantly lower than those of control group. The expressions of Wnt1, β-catenin and vimentin decreased significantly, while the expression of E-cadherin increased significantly. Conclusion The expression of miR-497 is low in the anoikis resistance SGC-7901 cells. miR-497 can inhibit the growth and metastasis of gastric cancer cells by blocking Wnt/β-catenin signaling pathway and EMT.

Regulation of Axon Initial Segment Diameter by COUP-TFI Fine-tunes Action Potential Generation / 神经科学通报·英文版

The axon initial segment (AIS) is a specialized structure that controls neuronal excitability via action potential (AP) generation. Currently, AIS plasticity with regard to changes in length and location in response to neural activity has been extensively investigated, but how AIS diameter is regulated remains elusive. Here we report that COUP-TFI (chicken ovalbumin upstream promotor-transcription factor 1) is an essential regulator of AIS diameter in both developing and adult mouse neocortex. Either embryonic or adult ablation of COUP-TFI results in reduced AIS diameter and impaired AP generation. Although COUP-TFI ablations in sparse single neurons and in populations of neurons have similar impacts on AIS diameter and AP generation, they strengthen and weaken, respectively, the receiving spontaneous network in mutant neurons. In contrast, overexpression of COUP-TFI in sparse single neurons increases the AIS diameter and facilitates AP generation, but decreases the receiving spontaneous network. Our findings demonstrate that COUP-TFI is indispensable for both the expansion and maintenance of AIS diameter and that AIS diameter fine-tunes action potential generation and synaptic inputs in mammalian cortical neurons.

The randomized controlled study on timolol preventing refractive regression after LASIK in high myopic eyes / 中华实验眼科杂志

Background Refractive regression is a common complication of high myopia after laser in situ keratomileusis (LASIK),and it affects the stability of surgery.Objective This study was to observe the preventive effect of timolol on refractive regression in high myopia after LASIK.Methods A perspective randomized controlled trial was performed under the approval of Affiliated Hospital of Zunyi Medical College and the informed consent of the patients.Sixty eyes of 60 patients with high myopia (-7.16±0.95) D for LASIK were randomized into experimental group and control group.Regular eye drops were topically administered in the patients after LASIK in both groups,and timolol 0.5 ％ was added topically from 1 day after LASIK.The uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),spherical equivalent (SE),corneal anterior surface curvature,intraocular pressure (IOP),central corneal thickness (CCT) were measured before LASIK,1 week,1 month,3 months and 6 months after LASIK,respectively.Residual stromal bed thickness was calculated before LASIK.The differences of above-mentioned indexes were analyzed and compared between the two groups and among the various time points using repetitive measurements analysis of variance,independent simple t test and Bonferroni test.Results No significant differences were found in the demography between the experimental group and the control group,including age,UCVA,BCVA,SE,IOP,corneal anterior surface curvature,CCT and residual stromal bed thickness (all at P＞0.05).UCVA was significantly different between the two groups among various time points (Fgroup =3.91,P＜0.05 ; Ftime =3.80,P＜0.05),and the UCVA was significantly higher in the experimental group than the control group 6 months after LASIK (t=2.97,P＜0.05),and UCVA was gradually increased as the lapse of postoperative time with the significant difference between 7 days and 6 months after LASIK in the experimental group (P＜0.05).No significant difference was seen in the BCVA between the two groups at various postoperative time points (Fgroup =2.44,P＞0.05;Ftime =2.31,P＞0.05).SE refraction in both groups were significantly reduced from 7 days through 6 months after LASIK,showing significant difference between the groups at various time points after LASIK(Fgroup =11.52,P＜0.05;Ftime =22.06,P＜0.05).The SE refraction was higher in the experimental group than that in the control group 6 months after LASIK (t =2.47,P＜0.05).Corrected IOP in the experimental group was lower than that of the control group at 7 days,1 month and 3 months after LASIK,respectively (Fgroup =14.83,P＜0.05).The change of CCT was not statistically different between the control group and the experimental group (Fgroup =0.04,P＞0.05).The anterior corneal surface curvature was steady in the experimental group during the following-up duration after LASIK,while the control group was growing gradually (Ftime =18.73,P＜0.05).Conclusions The study data show that topical administration of 0.5％ timolol early in high myopia following LASIK is effective for the reduction of the refractive regression.It is suggested that 0.5％ timolol can prevent cornea ectasia by lowering IOP.Reduction of the IOP may contribute to improving the regression after keratorefractive surgery in high myopic eyes.

Inhibition of apoptosis induced by galactose by c-myc antisense oligodeoxynucleotide in lens epithelial cells / 眼科研究

Background Various studies demonstrated that the apoptosis of lens epithelial cells(LECs) is associated with the overexpression of the c-myc gene in LECs induced by galactose.Inhibiting the abnormal expression of the c-myc gene in LECs is an effective approach to mitigate the pathogenesis and development of cataract.Objective The goal of this study is to investigate the inhibitory effects of c-myc antisense oligodeoxynucleotide(c-myc ASODN) on the apoptosis of LECs in the eye with galactose-induced cataract.Methods Galactose-induced cataract models were established by the retrobulbar injection of 0.2 mL of 20% galactose once per day.Lipo-antisense oligodeoxynucleotide(Lipo-ASODN,0.2 mL) was retrobulbarly injected 4 hours after the injection of galactose at one-day intervals.The animals were sacrificed and lenses were obtained to evaluate the apoptosis of LECs and the effect of c-myc ASODN on LECs apoptosis induced by galactose was examined by TUNEL assay after 7,14 and 24 days.The ultrastructural changes of LECs were examined under the transmission electron microscopy(TEM).Results A significant difference in the apoptotic rate of LECs was found among the 7 day,14 day and 24 day groups(F_(7 days)=3 418.495,P＜0.01;F_(14 days)=1137.555,P＜0.01;F_(24 days)=2198.871,P＜0.01).The apoptotic rate of LECs in the galactose group was markedly higher than that in the normal saline solution group 7 days,14 days and 24 days after the experiment(P＜0.01).The apoptotic rate of LECs in the galactose+lipo+ ASODN group significantly declined in comparison to the galactose group after 7 days,14 days and 24 days(P＜0.05).TUNEL assay showed the condensation,breakage and irregularity of the nuclei of apoptotic cells in the galactose group.The destruction of the ultrastructure of the cells and organelles were observed under the transmission electron microscope.Conclusion Galactose induces apoptosis of LECs in cataractogenesis.C-myc ASODN inhibits apoptosis of LECs induced by galactose.

Inhibitory effect of antisense oligodeoxynucleotide c-myc on the growth of lens epithelial cells induced by galactose / 第三军医大学学报

Objective To investigate the effects of antisense oligodeoxynucleotide c-myc (c-myc ASODN) on the growth of rabbit lens epithelial cells (LECs) induced by galactose. Methods Based on the translation initiation region of the second extron of c-myc gene, oligonucleotides were synthesized and modified with phosphorothioate. Lens epithelial cells were treated with galactose and c-myc ASODN. The effects of c-myc ASODN on the growth of LECs, cultured in high concentration of galactose, were observed by cytometry and MTT. Results The results demonstrated that c-myc ASODN at the doses of 2.5-10.0 ?mol/L inhibited the growth of LECs induced by galactose in a dose-dependent manner. Conclusion These results indicate that c-myc ASODN can inhibit the growth of LEC induced by galactose.