Expression and clinical significance of Semaphorin4D in non-small cell lung cancer and its impact on malignant behaviors of A549 lung cancer cells

Abstract

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 Sema4D in regulating the malignant behaviors of A549 cells by small interfering RNA (siRNA). Firstly, immunohistochemistry revealed that Sema4D 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 Sema4D expression was suppressed by Sema4D siRNA in A549 cells overexpressing Sema4D. Protein levels of Sema4D, 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 Sema4D 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 Sema4D might serve as a reliable tool for early prediction of NSCLC poor prognosis. Sema4D could play an important role in promoting tumor proliferation, migration and metastasis in the NSCLC, by influencing the Akt protein phosphorylation. Inhibition of Sema4D may be a useful approach for the treatment of NSCLC.

Keywords

semaphorin4D / non-small cell lung cancer / prognosis / RNA interference / proliferation / migration / invasion

References

[1] KolodkinAL, MatthesDJ, O’ConnorTP, et al.. Fasciclin IV: sequence, expression, and function during growth cone guidance in the grasshopper embryo. Neuron, 1992, 9(5): 831-845

[2] VodrazaP, KorostylevA, HirschbergA, et al.. The Semaphorin 4D-plexin-B signaling complex regulates dendritic and axonal complexity in developing neurons via diverse pathways. Eur J Neumsci, 2009, 30(7): 1193-1208

[3] LiM, O’sullivanKM, JonesL e a1. Endogenous CD100 promotes glomerular injury and macrophage recruitment in experimental crescentic glomerullonephritis. Immunology, 2009, 128(1): 114-122

[4] GiacobiniP, MessinaA, MorelloF, et al.. Semaphorin 4D regulates gonadotropin hormone-releasing hormone-1 neuronal migration through PlexinB1-Met complex. J cell Biol, 2008, 183(3): 555-566

[5] BasileJR, CastilhoRM, WilliamsVP, et al.. Semaphorin 4D provides a link between axon guidance processes and tumor-induced angiogenesis. Proc Natl Acad sci USA, 2006, 103(24): 9017-9022

[6] SierraJR, CorsoS, CaioneL, et al.. Tumor angiogenesis and progression are enhanced by Sema 4D produced by tumor-associated macrophages. J Exp Med, 2008, 205(7): 1673-1685

[7] ZhuL, BergmeierW, WuJ, et al.. Regulated surface expression and shedding support a dual role for semaphorin 4D in platelet responses to vascular injury. Proc Nati Acad Sci USA, 2007, 104(5): 1621-1626

[8] BasileJR, AfkhamiT, GutkindJS. Semaphorin4D/plexinB1 induces endothelial cell migration through the activation of PYK2, Src and the phosphatidylinositol 3-kinase-Akt pathway. Mol Cell Biol, 2005, 25(16): 6889-6898

[9] ConrottoP, ValdembriD, CorsoS, et al.. Sema4D induces angiogenesis through met recruitment by Plexin B1. Blood, 2005, 105(11): 4321-4329

[10] BrachmannS, FritschC, MairaSM, et al.. PI3K and mTOR inhibitors-a new generation of targeted anticancer agents. Curr Opin Cell Biol, 2009, 21(2): 194-198

[11] BasileJR, GavardJ, GutkindJS. Plexin-B1 utilizes RhoA and Rho kinase to promote the integrin-dependent activation of Akt and ERK and endothelial cell motility. J Biol Chem, 2007, 282(48): 34 888-34 895

[12] ChenY, ZhangL, LvR, et al.. Overexpression of Semaphorin4D indicates poor prognosis and prompts monocyte differentiation toward M2 macrophages in epithelial ovarian cancer. Asian Pac J Cancer Prev, 2013, 14(10): 5883-5890

[13] ChenY, ZhangL, WuHJ, et al.. Effect of semaphorin4D gene silencing on malignant behavior of human ovarian cancer SKOV3 cells. Zhonghua Zhong Liu Za Zhi (Chinese), 2011, 33(5): 324-330

[14] LiangYC, WuHG, XueHJ, et al.. Effects of PI3K inhibitor NVP-BKM120 on acquired resistance to gefitinib of human lung adenocarcinoma H1975 cells. J Huazhong Univ Sci Technolog Med Sci, 2013, 33(6): 845-851

[15] GrilleSJ, BellacosaA, UpsonJ, et al.. The protein kinase Akt induces epithelial mesenchymal transition and promotes enhanced motility and invasiveness of squamous cell carcinoma lines. Cancer Res, 2003, 63: 2172-2178

[16] GrandclementC, BorgC. Neuropilins: a new target for cancer therapy. Cancers (Basel), 2011, 3(2): 1899-1928