Wang Zhen, Ding Meiman, Qian Naiying, Song Beifeng, Yu Jiayin, Tang Jinlong, Wang Jingyu
Department of Pathology, The First Hospital of Jiaxing, Zhejiang, People's Republic of China.
The Criminal Investigation Detachment of Jiaxing Public Security Bureau, Zhejiang, People's Republic of China.
World J Surg Oncol. 2017 Mar 20;15(1):67. doi: 10.1186/s12957-017-1128-1.
Semaphorin 3D (SEMA3D) plays important roles in the genesis and progress of many cancers. However, the relationship between SEMA3D and colorectal cancer (CRC) remains unknown. The aim of this study was to investigate whether SEMA3D can be used as a predictive marker for the diagnosis, metastasis, and prognosis of CRC by assessing the expression of SEMA3D in the tissues and serum of CRC patients.
Real-time quantitative polymerase chain reaction (qPCR) was used to measure the expression of SEMA3D mRNA in 100 CRC tissues and matched normal tissues. qPCR was also used to detect the expression of SEMA3D mRNA in the CRC cell line RKO. RKO cells were transfected with SEMA3D small-interring RNA (siRNA) to interfere with endogenous SEMA3D. The migratory ability of control and SEMA3D siRNA-transfected RKO cells was determined by transwell assays. Enzyme-linked immunosorbent assay (ELISA) was utilized to detect the levels of SEMA3D in the serum of 80 CRC patients and 100 normal healthy controls. The expression of SEMA3D in 215 CRC tissues was assessed using immunohistochemistry (IHC). Then, statistical analyses were adopted to assess SEMA3D protein levels and clinical pathological characteristics.
The mRNA expression of SEMA3D was significantly lower in CRC tissues than in paired normal tissues (t = 5.027, P < 0.0001). Compared with normal healthy controls, the serum levels of SEMA3D were decreased significantly in CRC patients (t = 3.656, P = 0.0003). The expression of SEMA3D protein was linked to lymph node metastasis, and low expression led to lymph node metastasis (χ = 8.415, P = 0.004). The expression of SEMA3D in CRC tissues was a favorable prognostic factor. Patients with a higher expression of SEMA3D experienced longer survival (P = 0.002, log-rank [Mantel-Cox]; Kaplan-Meier). In addition, multivariate Cox's proportional hazard model revealed that SEMA3D is an independent prognostic marker (hazard ratio [HR] 1.818, 95% CI 1.063-3.110, P = 0.029). Moreover, transwell assays showed that knocking down SEMA3D significantly increased RKO cell migration (t = 9.268, P = 0.0008).
SEMA3D might function as a tumor suppressor during the formation and development of CRC. SEMA3D might become a predictive marker for the diagnosis, metastasis, and prognosis of CRC and provide a novel target for the prevention and treatment of CRC.
信号素3D（SEMA3D）在多种癌症的发生和发展中起重要作用。然而，SEMA3D与结直肠癌（CRC）之间的关系尚不清楚。本研究的目的是通过评估CRC患者组织和血清中SEMA3D的表达，探讨SEMA3D是否可作为CRC诊断、转移及预后的预测标志物。
采用实时定量聚合酶链反应（qPCR）检测100例CRC组织及配对正常组织中SEMA3D mRNA的表达。qPCR还用于检测CRC细胞系RKO中SEMA3D mRNA的表达。用SEMA3D小干扰RNA（siRNA）转染RKO细胞以干扰内源性SEMA3D。通过Transwell实验测定对照和SEMA3D siRNA转染的RKO细胞的迁移能力。采用酶联免疫吸附测定（ELISA）检测80例CRC患者和100例正常健康对照血清中SEMA3D的水平。采用免疫组织化学（IHC）评估215例CRC组织中SEMA3D的表达。然后，采用统计学分析评估SEMA3D蛋白水平及临床病理特征。
CRC组织中SEMA3D的mRNA表达明显低于配对的正常组织（t = 5.027，P < 0.0001）。与正常健康对照相比，CRC患者血清中SEMA3D水平显著降低（t = 3.656，P = 0.0003）。SEMA3D蛋白表达与淋巴结转移有关，低表达导致淋巴结转移（χ = 8.415，P = 0.004）。CRC组织中SEMA3D的表达是一个良好的预后因素。SEMA3D表达较高的患者生存期较长（P = 0.002，对数秩检验[Mantel-Cox]；Kaplan-Meier法）。此外，多因素Cox比例风险模型显示SEMA3D是一个独立的预后标志物（风险比[HR] 1.818，95%可信区间1.063 - 3.110，P = 0.029）。而且，Transwell实验表明敲低SEMA3D显著增加RKO细胞迁移（t = 9.268，P = 0.0008）。
SEMA3D在CRC形成和发展过程中可能起肿瘤抑制作用。SEMA3D可能成为CRC诊断、转移及预后的预测标志物，并为CRC的预防和治疗提供新靶点。
