Hypoxia results from long-term anti-angiogenic therapy and can stimulate hypoxia-inducible factors (HIFs). HIF-induced hy-poxia signaling is involved in various steps in tumor invasive-metastatic cascade. On the one hand, HIFs regulate epithelial-mesenchy-mal transition. On the other hand, the characteristics of pericytes around vessels and the links among endothelial cells can change;thus, tumor cells can more easily intravasate into blood vessels, survive in peripheral blood, and then reach specific organs, ultimately resulting in metastasis. This review discusses the emerging mechanisms of long-term anti-angiogenic therapy and the occurrence of metastasis.

This study was aimed to examine the effect of TREK-1 silencing on the function of astrocytes. Three 21-nucleotide small interfering RNA (siRNA) duplexes (siT1, siT2, siT3) targeting TREK-1 were constructed. Cy3-labeled dsRNA oligmers were used to determine the transfection efficiency in cultured astrocytes. TREK-1-specific siRNA duplexes (siT1, siT2, siT3) at the optimal concentration were transfected into cultured astrocytes, and the most efficient siRNA was identified by the method of immunocytochemical staining and Western blotting. The proliferation of astrocytes tranfected with TREK-1-targeting siRNA under hypoxia condition was measured by fluorescence-activated cell sorting (FACS). The results showed that TREK-1 was expressed in cultured astrocytes. The dsRNA oligmers targeting TREK-1 could be transfected efficiently in cultured astrocytes and down-regulate the expression of TREK-1 in astrocytes. Moreover, the down-regulation of TREK-1 in astrocytes contributed to the proliferation of astrocytes under hypoxia condition as determined by cell cycle analysis. It was concluded that siRNA is a powerful technique that can be used to knockdown the expression of TREK-1 in astrocytes, which helps further investigate the function of TREK-1 channel in astrocytes under physicological and pathological condition.

Objective To investigate the effect of signal transducer and activator of transcription-3(STAT-3)-mediated non-dependent vascular endothelial growth factor receptor-2(VEGFR-2) pathway on the radiosensitivity of non-small cell lung cancer (NSCLC) cells and its possible mechanism.Methods NSCLC cells were divided into control group, apatinib (VEGFR-2 inhibitor) group, apatinib+S3I-201(STAT-3 inhibitor) group, radiation (RT) group, RT+apatinib group, and RT+apatinib+S3I-201 group.Q-PCR and Western blot were used to measure the mRNA and protein expression of VEGFR-2, STAT-3, other proteins involved in the signaling pathway, hypoxia-inducible factor 1α(HIF-1α), and cyclin D1.The cellular radiosensitivity was determined by colony-forming assay and cell apoptosis and cell cycle distribution were evaluated by flow cytometry.Results For Calu-1 cells, there was no significant difference in the expression of VEGFR-2 mRNA and STAT-3 mRNA between the apatinib group and the control group (P>0.05);the apatinib group had significantly lower expression of HIF-1α mRNA and cyclin D1 mRNA than the control group (P<0.05);the apatinib+S3I-201 group had significantly lower mRNA and phosphorylated protein expression of VEGFR-2, STAT-3, and related downstream target proteins than the control group (F=304.54, P<0.01;F=118.99, P<0.01, F=144.34, P<0.01;F=529.66, P<0.01);compared with the control group, the apatinib+S3I-201 group and the apatinib group showed increases in apoptosis rate and proportion of cells in G2+M phase, and the apatinib+S3I-201 group had significantly greater increases than the apatinib group (F=72.37, P<0.01).Compared with Calu-1 cells, the radiosensitizing effect of apatinib on A549 cells was limited (SER[sensitizer enhancement ratio]=1.39).The radiosensitizing effect of apatinib+S3I-201 on A549 cells was significantly higher than that of apatinib (SER:1.72 vs.1.39, P=0.000).Conclusions The inhibition of STAT-3 can enhance the radiosensitivity of NSCLC cells.When VEGFR-2 is inhibited by apatinib, activated STAT-3 regulates the expression of cyclin D1 directly or indirectly to affect the radiosensitivity of NSCLC cells.The inhibition of VEGFR-2 and STAT-3 has a good radiosensitizing effect on NSCLC cells.

This study was aimed to examine the effect of TREK-1 silencing on the function of astrocytes. Three 21-nucleotide small interfering RNA (siRNA) duplexes (siT1, siT2, siT3) targeting TREK-1 were constructed. Cy3-labeled dsRNA oligmers were used to determine the transfection efficiency in cultured astrocytes. TREK-1-specific siRNA duplexes (siT1, siT2, siT3) at the optimal concentration were transfected into cultured astrocytes, and the most efficient siRNA was identified by the method of immunocytochemical staining and Western blotting. The proliferation of astrocytes tranfected with TREK-1-targeting siRNA under hypoxia condition was measured by fluorescence-activated cell sorting (FACS). The results showed that TREK-1 was expressed in cultured astrocytes. The dsRNA oligmers targeting TREK-1 could be transfected efficiently in cultured astrocytes and down-regulate the expression of TREK-1 in astrocytes. Moreover, the down-regulation of TREK-1 in astrocytes contributed to the proliferation of astrocytes under hypoxia condition as determined by cell cycle analysis. It was concluded that siRNA is a powerful technique that can be used to knockdown the expression of TREK-1 in astrocytes, which helps further investigate the function of TREK-1 channel in astrocytes under physicological and pathological condition.
Animals ; Astrocytes ; physiology ; Cells, Cultured ; Gene Silencing ; physiology ; Potassium Channels ; Potassium Channels, Tandem Pore Domain ; genetics ; RNA Interference ; physiology ; RNA, Small Interfering ; genetics ; Rats

Objective To investigate the value of ultrasonic direct signs and indirect signs in diagnosis of rotator cuff tears (RCTs).Methods Fifty-two patients underwent ultrasonography before arthroscopy were enrolled.The efficacy of ultrasonic direct and indirect signs in diagnosis of RCTs was calculated,and the accuracy of ultrasonic direct signs in diagnosis of subtypes for RCTs was compared with arthroscopic results.Results The accuracy of ultrasonic direct signs in diagnosis of the presence of tears,full-thickness tears and partial-thickness tears was 90.38％ (47/52),96.15％ (50/52)and 86.54％ (45/52),respectively.Additionally,the consistency of ultrasonic direct signs in diagnosis of subtypes for RCTs with arthroscopic results was good.With regard to ultrasonic indirect signs,the specificity of effusions including all subacromial/subdeltoid bursa effusions,intra-articular fluid and biceps tendon sheath effusions,subdeltoid bursa hernia and cartilage demarcation sign was 80.95％(17/21),90.48％ (19/21) and 95.24％ (20/21),respectively.Conclusion Ultrasonic direct signs combined with indirect signs have high clinical value in diagnosis of subtypes for RCTs.