Resveratrol suppresses the invasion and migration of human gastric cancer cells via inhibition of MALAT1-mediated epithelial-to-mesenchymal transition

Abstract

Resveratrol, a natural polyphenolic phytoalexin, was reported to exert multiple anticancer effects as a traditional Chinese medicine. However, research regarding the anticancer mechanism of resveratrol for the treatment and prevention of gastric cancer has reported conflicting results. In the present study, it was determined that resveratrol inhibited cell viability in a dose-dependent manner in the human gastric cancer cell line BGC823. Cell migration and invasion were suppressed significantly following treatment with 200 µM resveratrol. Additionally, resveratrol inhibited metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression, which was overexpressed in gastric cancer cells. Further experiments revealed that MALAT1 knockdown suppressed cell viability, migration, invasion and epithelial-to-mesenchymal transition in BGC823 cells. The present study indicated that resveratrol inhibited migration and invasion in human gastric cancer cells via suppressing MALAT1-mediated epithelial-to-mesenchymal transition, providing novel evidence for understanding the anticancer mechanism of resveratrol.

Keywords: epithelial-to-mesenchymal transition; gastric cancer; invasion; metastasis-associated lung adenocarcinoma transcript 1; migration; resveratrol.

Figure 1.

Resveratrol inhibits the viability of gastric cancer cells in a dose- and time-dependent manner. BGC823, SGC7901 and GES1 cells were treated with various doses of resveratrol (0, 5, 10, 25, 50, 100, 200 and 400 µM) for differing treatment times (24, 48 and 72 h). The cell viability was subsequently examined with a Cell Counting Kit-8 assay. **P<0.01 compared with the control group treated with 0 µM resveratrol for different treatment times.

Figure 2.

Resveratrol inhibits the migration and invasion of BGC823 cells, as demonstrated with Transwell and Matrigel assays. (A) Assessment of cell migration and invasion in BGC823 cells following treatment with or without resveratrol for 48 h. Scale bar=10 µm. The number of (B) migratory and (C) invasive cells was analyzed quantitatively. The values are presented as the mean ± standard deviation of three independent experiments. *P<0.05 and **P<0.01 compared with the mock group. Mock, group untreated with resveratrol.

Figure 3.

Expression levels of epithelial-to-mesenchymal transition marker proteins, including E-cadherin and vimentin in BGC823 cells treated with resveratrol for 48 h. (A) Western blot analysis of protein expression. (B) Quantitative analysis of the relative grey value of western blot bands. Data are represented as the mean ± standard deviation of three independent experiments. GAPDH was used as the reference gene. **P<0.01 compared with the mock group. Mock, group untreated with resveratrol.

Figure 4.

Expression levels of MALAT1 were analyzed by reverse transcription-quantitative polymerase chain reaction. (A) The expression of MALAT1 in BGC823 cells treated with resveratrol for 48 h. (B) The expression of MALAT1 in gastric cancer cell lines and a non-malignant gastric epithelium cell line. Data are represented as the mean ± standard deviation of three independent experiments. GAPDH was used as the reference gene. **P<0.01 compared with the Mock group or GES1 cells. MALAT1, metastasis-associated lung adenocarcinoma transcript 1; Mock, group untreated with resveratrol.

Figure 5.

Effect of MALAT1 knockdown on cell viability. (A) Efficiency of MALAT1 knockdown was evaluated with reverse transcription-quantitative polymerase chain reaction. (B) Cell viability following MALAT1 knockdown was measured with a Cell Counting Kit-8 assay in BGC823 cells. Cell transfection with siNC was used as the control. GAPDH was used as the reference gene. Data are represented as the mean ± standard deviation of three independent experiments. **P<0.01 compared with the siNC group. MALAT1, metastasis-associated lung adenocarcinoma transcript 1; siNC, negative control small-interfering RNA; siRNA-1 and −2, small interfering RNA targeting MALAT1.

Figure 6.

Effects of MALAT1 interference on the invasion and migration of BGC823 cells. (A) Transwell and Matrigel assays demonstrated that MALAT1 knockdown suppressed the migration and invasion of gastric cancer cells. Scale bar=10 µm. Quantitative analysis of the number of (B) migratory and (C) invasive cells. Cell transfection with siNC was used as the control. Data are represented as the mean ± standard deviation of three independent experiments. **P<0.01 compared with the siNC group. MALAT1, metastasis-associated lung adenocarcinoma transcript 1; siNC, negative control small-interfering RNA; siRNA-1, small interfering RNA targeting MALAT1.

Figure 7.

Effects of MALAT1 knockdown on epithelial-to-mesenchymal transition of BGC823 cells. (A) Reverse transcription-quantitative polymerase chain reaction was performed to test the mRNA expression levels of E-cadherin and vimentin. Cell transfection with siNC was used as the control. GAPDH was used as the reference gene. Data are represented as the mean ± standard deviation of three independent experiments. *P<0.05 and **P<0.01 compared with the siNC group. (B) Expression of epithelial-to-mesenchymal transition-associated proteins, including E-cadherin and vimentin, in BGC823 cells transfected with siRNA-1/siNC and treated or untreated with resveratrol. (C) Relative grey value analysis of protein expression levels of E-cadherin and vimentin. GAPDH was used as the loading control. *P<0.05 and **P<0.01 as indicated. MALAT1, metastasis-associated lung adenocarcinoma transcript 1; siNC, negative control small-interfering RNA; siRNA-1, small interfering RNA targeting MALAT1.