Dextran sulfate inhibition on human gastric cancer cells invasion, migration and epithelial-mesenchymal transformation

Abstract

The objective of the present study was to observe the influence of dextran sulfate (DS) on the proliferation, invasion and migration of AGS, BGC-23, GES-1, MGC-803 and SGC-7901 cells. Additionally, the possible inhibition mechanism of DS on BGC-823 cells epithelial-mesenchymal transition (EMT) was explored. The cells in the control and experimental group were treated with PBS and DS respectively. The effect of DS on the invasion and migration of these five types of cells were investigated using Transwell invasion and migration assays. Immunocytochemistry, western blotting and reverse transcription-polymerase chain reaction (RT-PCR) assays were used to measure gene and protein expression of hypoxia-inducible factor 1α (HIF1-a) and EMT associated factors [Twist, E-cadherin, N-cadherin and β-catenin] of BGC-823 cells. According to the results of CCK-8, DS significantly decreased the proliferation of AGS, SGC-7901 and BGC-823 cells to different extents, but there were no notable differences for MGC-803 cells. Transwell migration and invasion results demonstrated that, compared with the control group, DS reduced the migration and invasion of every types of cells to different extents, and the inhibition to BGC-823 cells invasion is the most notably. Immunofluorescence, RT-PCR and western blot analysis results indicated that HIF-1α, Twist and N-cad expressions levels had different degrees of reduction in the experimental group following DS treatment; however, the expression level of E-cad had increased. In conclusion, DS inhibited the proliferation of AGS, BGC-823, SGC-7901 and GES-1 cells, the inhibition degree may be associated with the differentiation degree of every cancer cell, the higher the differentiation degree, the stronger the inhibition. DS inhibited migration and invasion of the five types of gastric cancer cells in different degree. DS may inhibit EMT of BGC-823 by inhibiting Wnt signaling.

Keywords: dextran sulfate; epithelial-mesenchymal transition; human gastric cancer cells; metastasis.

Figure 1.

Dextran sulfate impact on the proliferation of five types of cells. The Cell Counting kit-8 detection of (A) AGS, (B) SGC-7901, (C) BGC-823, (D) MGC-803 and (E) GES-1. *P<0.05, **P<0.01 vs. the control. OD, optical density.

Figure 2.

Dextran sulfate inhibits the invasive ability and migration ability of gastric cells. (A) Matrigel invasion and (B) Transwell migration assays for the number cells that passed through the membrane, **P<0.01 vs. control group. ^#P<0.05 and ^##P<0.01.

Figure 3.

Immunofluorescence staining of HIF-1α and epithelial-mesenchymal transition associated factors in BGC-823 cells. Statistical analysis of immunofluorescence staining of HIF-1α, β-catenin, E-cad and N-cad in BGC-823 cells. *P<0.05 and **P<0.01, experimental vs. control group. HIF-1α, hypoxia-inducible factor 1α; E-cad, E-cadherin; N-cad, N-cadherin; β-cat, β-catenin.

Figure 4.

Reverse transcription-quantitative polymerase chain reaction detection of HIF-1α and epithelial-mesenchymal transition associated factors mRNA expression in BGC-823 cells. Electrophoretic band of HIF-1^α associated factors β-catenin, E-cad and N-cad mRNA in hypoxia and normoxia in BGC-823 cells. +, time in experimental group; -, time in control group. HIF-1α, hypoxia-inducible factor 1α; E-cad, E-cadherin; N-cad, N-cadherin; β-cat, β-catenin.

Figure 5.

Reverse transcription-polymerase chain reaction statistics of HIF-1α, Twist, β-catenin, E-cad and N-cad mRNA expression level. *P<0.05 and **P<0.01 experimental vs. control group. HIF-1α, hypoxia-inducible factor 1α; E-cad, E-cadherin; N-cad, N-cadherin.

Figure 6.

Western blot detection of epithelial-mesenchymal transition associated factors protein expression in BGC-823 cells. Electrophoretic band of epithelial-mesenchymal transition-associated factors Twist, β-catenin, E-cad and N-cad protein expression in hypoxia and in normoxia in BGC-823 cells. HIF-1α, hypoxia-inducible factor 1α; E-cad, E-cadherin; N-cad, N-cadherin; β-cat, β-catenin.

Figure 7.

Western blot statistics of epithelial-mesenchymal transition-associated factors Twist, β-catenin, E-cad and N-cad protein expression level in hypoxia and in normoxia. *P<0.05 and **P<0.01 experimental vs. control group. HIF-1α, hypoxia-inducible factor 1α; E-cad, E-cadherin; N-cad, N-cadherin; β-cat, β-catenin.