Recombinant human decorin suppresses liver HepG2 carcinoma cells by p21 upregulation

Yucheng Zhang, Yali Wang,^* Zhenwu Du, Qian Wang, Mei Wu, Xiaofeng Wang, Lingling Wang, Linlin Cao, Abdu Selim Hamid, Guizhen Zhang^*

Central Laboratory, China-Japan Union Hospital, Jilin University, Changchun, People's Republic of China

^*These authors contributed equally to this work

Background: Decorin is a multifunctional molecule of the extracellular matrix and impedes different kinds of tumor cell growth, but the role and molecular mechanism by which decorin inhibits HepG2 cells is not fully understood. Our objective was to construct recombinant human decorin (pcDNA3.1-DCN) and to explore the mechanism by which it inhibits HepG2 cells.
Methods: This experiment was divided into three groups, ie, a control group, an empty vector group, and a pcDNA3.1-DCN group. pcDNA3.1-DCN was constructed using recombinant DNA technology, and the vector for pcDNA3.1-DCN and pcDNA3.1 was then transfected into HepG2 cells using Lipofectamine 2000.
Results: Compared with cells in the control group and in the empty vector group, growth of cells in the pcDNA3.1-DCN group was significantly suppressed, the ratios of cells in the G0/G1 phases and proportion of early apoptotic cells were significantly increased, and the level of p21^WAF1/CIP1 (p21) protein was markedly upregulated (P < 0.05). However, there was no significant difference among the three groups in p53 protein expression (P > 0.05).
Conclusion: The pcDNA3.1-DCN vector was successfully constructed and transfected into HepG2 cells, and decorin overexpression suppressed the growth of HepG2 cells by upregulation of p21 via a p53-independent pathway.

Keywords: decorin, HepG2, liver cancer, p21^WAF1/CIP1, pcDNA3.1