Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Nov 21;13(43):5718-24.
doi: 10.3748/wjg.v13.i43.5718.

Silencing SMYD3 in hepatoma demethylates RIZI promoter induces apoptosis and inhibits cell proliferation and migration

Li-Bo Chen  1 , Jun-Yao Xu, Zhen Yang, Guo-Bin Wang
Affiliations

Silencing SMYD3 in hepatoma demethylates RIZI promoter induces apoptosis and inhibits cell proliferation and migration

Li-Bo Chen et al. World J Gastroenterol. .

Abstract

Aim: To investigate the role of SMYD3 in hepatocellular carcinoma (HCC) development and progression and to verify whether its regulation activity was through RIZ1 inactivation.

Methods: Expression of SMYD3 in HCC cell lines and tissues were measured; silencing of SMYD3 by RNA interference (RNAi) was effectuated, hepatoma cell proliferation, migration and apoptosis were tested, with RIZ1 CpG promoter methylation, and corresponding mRNA expression were investigated.

Results: SMYD3 over-expression in HCC was associated with RIZ1 hypermethylation and mRNA down-expression. Suppression of SMYD3 expression de-methylated RIZ1 CpG promoter (P < 0.01) and increased RIZ1 mRNA expression (P < 0.01). Consequently, SMYD3 down-expression with RIZ1 de-methylation strongly inhibited hepatoma cell growth (MTT inhibitory rates: Pgenesil-1-s1 60.95% +/- 7.97%, Pgenesil-1-s2 72.14% +/- 9.68% vs Pgenesil-1-hk 6.89% +/- 4.12%, P < 0.01) and migration (Pgenesil-1-s1 4.24% +/- 1.58%, Pgenesil-1-s1 4.87% +/- 0.73% vs Pgenesil-1 19.03% +/- 4.63%, Pgenesil-1-hk 19.95% +/- 5.21%, P < 0.01) and induced apoptosis (FCM subG1 phase Pgenesil-1-s1 19.07% +/- 1.78%, Pgenesil-1-s2 17.68% +/- 2.36% vs Pgenesil-1 0.47% +/- 0.12%, Pgenesil-1-hk 1.46% +/- 0.28%, P < 0.01. TUNEL-positive cells: Pgenesil-1-s1 40.24% +/- 5.18%, Pgenesil-1-s2 38.48% +/- 4.65% vs Pgenesil-1 2.18% +/- 1.34%, Pgenesil-1-hk 2.84% +/- 1.22%, P < 0.01) in HepG2 cells.

Conclusion: These results demonstrate that SMYD3 plays a critical role in the carcinogenesis and progression of HCC. The proliferation, migration induction and apoptosis inhibition activities of SMYD3 may be mediated through RIZ1 CpG promoter hypermethylation.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Enhanced expression of SMYD3 in HCC. A: The expression of SMYD3 genes was determined by RT-PCR and GAPDH served as an internal control; B: Representative images of immunohistochemical staining of accumulated SMYD3 protein in HCC tissue, but not in peri-cancerous tissue.
Figure 2
Figure 2
RNAi specifically inhibits SMYD3 expression in HCC cell lines. A: Schematic drawing of the Pgenesil-1 vector; B: The predicted secondary structures of the Pgenesil-1-s1 and Pgenesil-1-s2 transcripts target SMYD3 are shown; C: 48h after transfection, Western blot analysis showed the inhibitory effect of plasmids expressing SMYD3 shRNAs in HepG2 and SMMC-7721 cells.
Figure 3
Figure 3
Inhibition of SMYD3 reduces hepatoma cell proliferation (MTT assays).
Figure 4
Figure 4
Inhibition of SMYD3 reduces hepatoma cell migration. A: Representative cells (blue) invade through Matrigel and membrane; B: The percentage of cells successfully passing through the matrigel and membrane (P < 0.01).
Figure 5
Figure 5
Inhibition of SMYD3 promotes apoptosis in hepatoma cells upon serum deprivation. A: FCM analysis of HepG2 cells 48 h after transfection (P < 0.01). B: TUNEL assay of cell apoptosis with siRNA suppression of SMYD3 expression in HepG2 (brown staining cells) (P < 0.01).
Figure 6
Figure 6
Inhibition of SMYD3 de-methylates RIZ1 promoter CpG islands and reexpresses RIZ1 in hepatoma Cells. A: Methylation specific PCR (MSP) assay of RIZ1 promoter. M: Methylated; U: Unmethylated; B: RIZ1 mRNA expression, GAPDH served as internal control (RT-PCR).
See this image and copyright information in PMC

References

    1. Egger G, Liang G, Aparicio A, Jones PA. Epigenetics in human disease and prospects for epigenetic therapy. Nature. 2004;429:457–463. - PubMed
    1. Lund AH, van Lohuizen M. Epigenetics and cancer. Genes Dev. 2004;18:2315–2335. - PubMed
    1. Yu J, Zhang H, Gu J, Lin S, Li J, Lu W, Wang Y, Zhu J. Methylation profiles of thirty four promoter-CpG islands and concordant methylation behaviours of sixteen genes that may contribute to carcinogenesis of astrocytoma. BMC Cancer. 2004;4:65. - PMC - PubMed
    1. Alaminos M, Dávalos V, Ropero S, Setién F, Paz MF, Herranz M, Fraga MF, Mora J, Cheung NK, Gerald WL, et al. EMP3, a myelin-related gene located in the critical 19q13.3 region, is epigenetically silenced and exhibits features of a candidate tumor suppressor in glioma and neuroblastoma. Cancer Res. 2005;65:2565–2571. - PubMed
    1. Hamamoto R, Furukawa Y, Morita M, Iimura Y, Silva FP, Li M, Yagyu R, Nakamura Y. SMYD3 encodes a histone methyltransferase involved in the proliferation of cancer cells. Nat Cell Biol. 2004;6:731–740. - PubMed

Publication types

MeSH terms