Xu Jun-yao, Chen Li-bo, Xu Jun-yang, Yang Zhen, Xu Rong-hua, Wei Hai-yan
Department of Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhonghua Wai Ke Za Zhi. 2006 Apr 1;44(7):481-4.
To determine the potential of SMYD3 as a therapeutic target for hepatocellular carcinoma (HCC) by potent and highly sequence-specific RNA interference (RNAi) technique.
The mRNA of SMYD3 was detected by RT-PCR in different HCC cell lines, such as HepG2, Hep3B and SMMC7721. Recombinant SMYD3 shRNA plasmid Pgenesil-1-s was constructed and transfected into HepG2 cells, and Western blot was used to identify the down regulation of SMYD3 protein expression after transfection. MTT and flow cytometry analysis (FCM) were respectively applied to analysis cell proliferation and apoptosis. In vivo study was carried out by injecting recombinant SMYD3 shRNA plasmids into transplanted tumors of nude mice.
The expression of SMYD3 mRNA was abundant in HCC cell lines HepG2, Hep3B, SMMC7721, whereas none in normal hepatic cell line L-02. RNA interference was able to suppress SMYD3 expression greatly and then inhibited cell growth effectively and induced apoptosis of HepG2 cells efficiently. After injection of recombinant SMYD3 shRNA plasmid, transplanted tumors grew slowly and reduced in size and weight when compared with those of control groups (P < 0.01).
SMYD3 plays a major role in occurrence and progress of HCC. Inhibition of SMYD3 by RNAi can induce apoptosis in HepG2 cells and suppress tumor growth in nude mice. Therefore SMYD3 could be an ideal therapeutic target for HCC.
通过高效且序列特异性强的RNA干扰（RNAi）技术，确定SMYD3作为肝细胞癌（HCC）治疗靶点的潜力。
采用RT-PCR检测不同肝癌细胞系如HepG2、Hep3B和SMMC7721中SMYD3的mRNA。构建重组SMYD3 shRNA质粒Pgenesil-1-s并转染至HepG2细胞，采用蛋白质免疫印迹法鉴定转染后SMYD3蛋白表达的下调情况。分别应用MTT法和流式细胞术分析（FCM）分析细胞增殖和凋亡情况。通过向裸鼠移植瘤内注射重组SMYD3 shRNA质粒进行体内研究。
SMYD3 mRNA在肝癌细胞系HepG2、Hep3B、SMMC7721中表达丰富，而在正常肝细胞系L-02中无表达。RNA干扰能够显著抑制SMYD3表达，进而有效抑制细胞生长并高效诱导HepG2细胞凋亡。注射重组SMYD3 shRNA质粒后，与对照组相比，移植瘤生长缓慢，体积和重量减小（P < 0.01）。
SMYD3在肝癌的发生和发展中起主要作用。RNAi抑制SMYD3可诱导HepG2细胞凋亡并抑制裸鼠肿瘤生长。因此，SMYD3可能是肝癌理想的治疗靶点。
