This study aimed to explore Semaphrin4D（Sema4D） expression and clinical significance in non-small cell lung cancer（NSCLC）, and to define the roles and mechanisms of Sema4 D in regulating the malignant behaviors of...This study aimed to explore Semaphrin4D（Sema4D） expression and clinical significance in non-small cell lung cancer（NSCLC）, and to define the roles and mechanisms of Sema4 D in regulating the malignant behaviors of A549 cells by small interfering RNA（siRNA）. Firstly, immunohistochemistry revealed that Sema4 D was more frequently expressed in NSCLC than in lung benign lesion（P〈0.05） and its overexprssion was associated with low differentiation（P〈0.05）, poor pTNM staging（P〈0.05） and occurrence of lymph node（LN） metastasis（P〈0.05）. Endogenous Sema4 D expression was suppressed by Sema4 D siRNA in A549 cells overexpressing Sema4 D. Protein levels of Sema4 D, total Akt and p-Akt were examined by Western blotting. Cell proliferation, migration and invasion abilities were measured by MTT assay and Transwell assay respectively. Results showed that Sema4 D siRNA significantly suppressed phosphorylation of AKT in A549 cells, but it did not alter total AKT expression. In addition, efficient down-regulation of SemaD significantly inhibit cell proliferation（P〈0.05）, migration（P〈0.05） and invasion（P〈0.05） in A549 cells. These findings suggest that Sema4 D might serve as a reliable tool for early prediction of NSCLC poor prognosis. Sema4 D could play an important role in promoting tumor proliferation, migration and metastasis in the NSCLC, by influencing the Akt protein phosphorylation. Inhibition of Sema4 D may be a useful approach for the treatment of NSCLC.展开更多
Background Hypoxia promotes tumor angiogenesis and hypoxia-inducible factor-1 alpha （HIF-lg） plays a pivotal role in this process. Recently identified pro-angiogenic factor, semaphorin4D （Sema4D） also promotes ang...Background Hypoxia promotes tumor angiogenesis and hypoxia-inducible factor-1 alpha （HIF-lg） plays a pivotal role in this process. Recently identified pro-angiogenic factor, semaphorin4D （Sema4D） also promotes angiogenesis and enhances invasive proliferation in some tumors. Furthermore, tumor-associated macrophages （TAMs） can increase the expression of HIF-la and Sema4D in cancer cells and thus influence tumor growth and progression. The purpose of this study was to evaluate the effect of TAMs on the expression of Sema4D and HIF-la and the impact of biologic behavior in colon cancer cells. Methods Immunohistochemistry was used to analyze HIF-la and Sema4D expression in 86 curatively resected colon cancer samples and 52 normal colon tissues samples. The relationship between their expression and clinicopathological factors was analyzed. Furthermore, macrophage-tumor cell interactions, such as metastasis, angiogenesis, were also studied using in vitro co-culture systems. Statistical analysis was performed using SPSS 17.0 software （SPSS Inc., USA）. Differences between two groups were analyzed with Student＇s t test. Results HIF-la （58%） and Sema4D （60%） were expressed at a significantly higher level in tumors than in normal tissues （P 〈0.01, for both）. Furthermore, HIF-la and Sema4D expression was significantly correlated with lymphatic metastasis, specific histological types and TNM stages （P 〈0.05）, but not with age and tumor size （P 〉0.05）. Sema4D expression was correlated with that of HIF-la （r=0.567, P 〈0.01）. TAMs markedly induced HIF-la and Sema4D expression in colon cancer calls and subsequently increased their migration and invasion. Conclusions HIF-la and Sema4D expression are closely related to lymphatic metastasis, specific histological types and TNM stages in colon cancer. Furthermore, TAMs promote migration and invasion of colon cancer cells and endothelial tube formation, possibly through up-regulation of HIF-la and Sema4D.展开更多
Summary： Skeletal fluorosis is a chronically metabolic bone disease with extensive hyperostosis osteosclerosis caused by long time exposure to fluoride. Skeletal fluorosis brings about a series of abnormal changes of...Summary： Skeletal fluorosis is a chronically metabolic bone disease with extensive hyperostosis osteosclerosis caused by long time exposure to fluoride. Skeletal fluorosis brings about a series of abnormal changes of the extremity, such as joint pain, joint stiffness, bone deformity, etc. Differentiation and maturation of osteoblasts were regulated by osteoclasts via Sema4D/Plexin-B 1 signaling pathway. Furthermore, the differentiation and maturation of osteoclasts are conducted by osteoblasts via RANKL/RANK/OPG pathway. Both of these processes form a feedback circuit which is a key link in skeletal fluorosis. In this study, an osteoblast-osteoclast co-culture model in vitro was developed to illustrate the mechanism of skeletal fluorosis. With the increase of fluoride concentration, the expression level of Sema4D was decreased and TGF-β1 was increased continuously. OPG/RANKL mRNA level, however, increased gradually. On the basis of that, the inhibition of Sema4D/Plexin-B1/RhoA/ROCK signaling pathway caused by fluoride promoted the level of TGF-β1 and activated the proliferation of osteoblasts. In addition, osteroprotegerin （OPG） secreted by osteoblasts was up-regulated by fluoride. The competitive combination of OPG and RANKL was strengthened and the combination of RANKL and RANK was hindered. And then the differentiation and maturation of osteoclasts were inhibited, and bone absorption was weakened, leading to skeletal fluorosis.展开更多
基金supported by the National Natural Science Foundation of China(No.30973473)
文摘This study aimed to explore Semaphrin4D（Sema4D） expression and clinical significance in non-small cell lung cancer（NSCLC）, and to define the roles and mechanisms of Sema4 D in regulating the malignant behaviors of A549 cells by small interfering RNA（siRNA）. Firstly, immunohistochemistry revealed that Sema4 D was more frequently expressed in NSCLC than in lung benign lesion（P〈0.05） and its overexprssion was associated with low differentiation（P〈0.05）, poor pTNM staging（P〈0.05） and occurrence of lymph node（LN） metastasis（P〈0.05）. Endogenous Sema4 D expression was suppressed by Sema4 D siRNA in A549 cells overexpressing Sema4 D. Protein levels of Sema4 D, total Akt and p-Akt were examined by Western blotting. Cell proliferation, migration and invasion abilities were measured by MTT assay and Transwell assay respectively. Results showed that Sema4 D siRNA significantly suppressed phosphorylation of AKT in A549 cells, but it did not alter total AKT expression. In addition, efficient down-regulation of SemaD significantly inhibit cell proliferation（P〈0.05）, migration（P〈0.05） and invasion（P〈0.05） in A549 cells. These findings suggest that Sema4 D might serve as a reliable tool for early prediction of NSCLC poor prognosis. Sema4 D could play an important role in promoting tumor proliferation, migration and metastasis in the NSCLC, by influencing the Akt protein phosphorylation. Inhibition of Sema4 D may be a useful approach for the treatment of NSCLC.
基金This study was supported in part by grants from the National Youthful Science Foundation of China （No. 81101858） and the Natural Science Foundation of Shandong Province of China （No. BS2011 SW046）. Conflict of interest： none.
文摘Background Hypoxia promotes tumor angiogenesis and hypoxia-inducible factor-1 alpha （HIF-lg） plays a pivotal role in this process. Recently identified pro-angiogenic factor, semaphorin4D （Sema4D） also promotes angiogenesis and enhances invasive proliferation in some tumors. Furthermore, tumor-associated macrophages （TAMs） can increase the expression of HIF-la and Sema4D in cancer cells and thus influence tumor growth and progression. The purpose of this study was to evaluate the effect of TAMs on the expression of Sema4D and HIF-la and the impact of biologic behavior in colon cancer cells. Methods Immunohistochemistry was used to analyze HIF-la and Sema4D expression in 86 curatively resected colon cancer samples and 52 normal colon tissues samples. The relationship between their expression and clinicopathological factors was analyzed. Furthermore, macrophage-tumor cell interactions, such as metastasis, angiogenesis, were also studied using in vitro co-culture systems. Statistical analysis was performed using SPSS 17.0 software （SPSS Inc., USA）. Differences between two groups were analyzed with Student＇s t test. Results HIF-la （58%） and Sema4D （60%） were expressed at a significantly higher level in tumors than in normal tissues （P 〈0.01, for both）. Furthermore, HIF-la and Sema4D expression was significantly correlated with lymphatic metastasis, specific histological types and TNM stages （P 〈0.05）, but not with age and tumor size （P 〉0.05）. Sema4D expression was correlated with that of HIF-la （r=0.567, P 〈0.01）. TAMs markedly induced HIF-la and Sema4D expression in colon cancer calls and subsequently increased their migration and invasion. Conclusions HIF-la and Sema4D expression are closely related to lymphatic metastasis, specific histological types and TNM stages in colon cancer. Furthermore, TAMs promote migration and invasion of colon cancer cells and endothelial tube formation, possibly through up-regulation of HIF-la and Sema4D.
基金suppooted by the National Natural Science Foundation of China(No.81372941)
文摘Summary： Skeletal fluorosis is a chronically metabolic bone disease with extensive hyperostosis osteosclerosis caused by long time exposure to fluoride. Skeletal fluorosis brings about a series of abnormal changes of the extremity, such as joint pain, joint stiffness, bone deformity, etc. Differentiation and maturation of osteoblasts were regulated by osteoclasts via Sema4D/Plexin-B 1 signaling pathway. Furthermore, the differentiation and maturation of osteoclasts are conducted by osteoblasts via RANKL/RANK/OPG pathway. Both of these processes form a feedback circuit which is a key link in skeletal fluorosis. In this study, an osteoblast-osteoclast co-culture model in vitro was developed to illustrate the mechanism of skeletal fluorosis. With the increase of fluoride concentration, the expression level of Sema4D was decreased and TGF-β1 was increased continuously. OPG/RANKL mRNA level, however, increased gradually. On the basis of that, the inhibition of Sema4D/Plexin-B1/RhoA/ROCK signaling pathway caused by fluoride promoted the level of TGF-β1 and activated the proliferation of osteoblasts. In addition, osteroprotegerin （OPG） secreted by osteoblasts was up-regulated by fluoride. The competitive combination of OPG and RANKL was strengthened and the combination of RANKL and RANK was hindered. And then the differentiation and maturation of osteoclasts were inhibited, and bone absorption was weakened, leading to skeletal fluorosis.
文摘目的:研究肿瘤相关巨噬细胞(TAMs)对人胃癌SGC-7901细胞系生物学功能的影响。方法 :采用佛波酯(PMA)、白细胞介素IL-4和IL-13体外诱导人M2型巨噬细胞,细胞免疫荧光鉴定TAMs。Transwell非接触式共培TAMs和胃癌SGC-7901细胞,侵袭实验、迁移实验检测肿瘤相关巨噬细胞(TAMs)对胃癌SGC-7901细胞侵袭和迁移的影响,酶联免疫吸附法(ELISA)检测实验组和空白对照组胃癌SGC-7901细胞上清中分泌型Sema4D的变化。结果:细胞免疫荧光鉴定M2型巨噬细胞诱导成功;在Transwell共培养体系中,TAMs共培养的胃癌SGC-7901细胞形态学发生改变;Transwell侵袭实验、迁移实验表明,细胞侵袭转移力增强(P<0.01)。与TAMs共培养的胃癌SGC-7901细胞的上清液分泌型Sema4D蛋白明显增多,较空白对照组差异有统计学意义(1224.13±29.43比637.15±33.84,P<0.01)。结论 :TAMs可促进胃癌细胞的浸润转移,其原因可能与分泌型Se m a4D蛋白的表达上调有关。
