Polyamines Microenvironment On The Migrationof Hepg2 Cells And Smmc-7721 Cells In Vitro

Background:Hepatocellular carcinoma(HCC) is one of the most common malignant tumor in the world, which is largely due to its high incidences and death rates. In recent years, Although the use of early diagnosis, chemotherapy, radiotherapy and operation treatment method to the liver cancer has been improved to a certain extent, but the prognosis of patients with HCC is still not ideal. Polyamine is a positively charged small molecule aliphatic compounds, which include putrescine(Put), spermidine(Spd) and spermine(Spm). Polyamines exerted widely physiological and pathophysiological effects, such as proliferation, differentiation, and apoptosis. Recent articles show high expression of endogenous polyamines content changes and Akt1 are closely related, but the biological function and molecular mechanism of polyamine and Akt1 in HCC remain unknown.Objective:Polyamine is a positively charged small molecule aliphatic compounds, which include putrescine(Put), spermidine(Spd) and spermine(Spm). It widely exists in the nature, for example: the cells of plants and animals in prokaryotic cells, bacteria, virus, yeast, or mammalian cells contain polyamines certain, it is necessary for most life natural components of organ. In normal circumstances, its content in tissues and fluids is very small, while it is much higher in the tumors tissues. In addition, the intracellular polyamines are related to tumor growth, invasion and migration. In this study, we examine the effect of polyamines at three different concentrations on hepatocellular carcinoma cells growth, migration, invasion and explore the role of the related molecular mechanism.Methods:HepG2 and SMMC-7721 cells were used in this study. Then, Akt1 gene was transfected into these two kinds of HCC cells, three different concentrations of exogenous polyamines were added to the culture medium. Including low(0.008 nmol/mL Put, 0.05 nmol/mL Spm, 0.1 nmol/mL Spd), middle(0.08 nmol/mL Put, 0.5 nmol/mL Spm, 1 nmol/mL Spd), high concentration of polyamines(0.8 nmol/mL Put, 5 nmol/mL Spm, 10 nmol/mL Spd). Each group has a negative control, cells were cultured for 15 days or 30 days. Western blotting analysis were used to detect the protein levels of Akt1, AKT, MMP9, ODC, HIF1α, P27kip1, Integrinα6, SSAT and VEGF.Results:HepG2 cells, HepG2-Akt1 cells, SMMC-7721 cells and SMMC-7721-Akt1 cells showed different invasion, migration, proliferation abilities in various concentration of polyamines, and the polyamines can promote HCC cells proliferation, migration and invasion in a time and dose dependent manner. Western blot results showed that polyamine could affect the protein expression of ornithine decarboxylase(ODC), spermidine and spermine acetyltransferase(SSAT), hypoxia-inducible factor(HIF1α), Akt1, integrins(Integrin α6), metalloproteinases(MMP9), vascular endothelial growth factor(VEGF) and P27kip1.Conclusion:The high concentration of polyamines can promote the proliferation, migration and invasion of the four kinds of HCC cells(Hep G2, HepG2-Akt1, SMMC-7721 and SMMC-7721-Akt1). Moreover, the improvement effects of polyamines on Akt1-transfected cells were significantly higher than those of non-transfected cells, indicating that Akt1 plays an important role in polyamines-mediated tumor cell proliferation, migration and invasion.