Tuberc Respir Dis.  2009 Mar;66(3):178-185. 10.4046/trd.2009.66.3.178.

The Effect of Epigallocatechin-3-gallate on HIF-1alpha and VEGF in Human Lung Cancer Cell Line

• Song JH
• Jeon EJ
• Kwak HW
• Lee HM
• Cho SG
• Kang HK
• Park SW
• Lee JH
• Lee BO
• Jung JW
• Choi JC
• Shin JW
• Kim KJ
• Kim JY
• Park IW
• Choi BW

• KMID: 1846377
• DOI: http://doi.org/10.4046/trd.2009.66.3.178

Abstract

BACKGROUND: Epigallocatechin-3-gallate (EGCG) is the major catechin in green tea, and has shown antiproliferative, antiangiogenic, antimetastatic and cell cycle pertubation activity in various tumor models. Hypoxia can be induced because angiogenesis is insufficient for highly proliferating cancer. Hypoxia-inducible factor-1alpha (HIF-1alpha) and its downstream target, vascular endothelial growth factor (VEGF), are important for angiogenesis, tumor growth and metastasis. The aim of this study was to determine how hypoxia could cause changes in the cellular phenomena and microenvironment in a non-small cell culture system and to examine the effects of EGCG on a HIF-1alpha and VEGF in A549 cell line.
METHODS
A549 cells, a non-small cell lung cancer cell line, were cultured with DMEM and 10% fetal bovine serum. A decrease in oxygen tension was induced using a hypoxia microchamber and a CO2-N2 gas mixture. Gas analysis and a MTT assay were performed. The A549 cells were treated with EGCG (0, 12.5, 25, 50 micromol/L), and then examined by real-time-PCR analysis of HIF-1alpha, VEGF, and beta-actin mRNA.
RESULTS
Hypoxia reduced the proliferation of A549 cells from normoxic conditions. EGCG inhibited HIF-1alpha transcription in A549 cells in a dose-dependent manner. Compared to HIF-1alpha, VEGF was not inhibited by EGCG.
CONCLUSION
HIF-1alpha can be inhibited by EGCG. This suggests that targeting HIF-1alpha with a EGCG treatment may have therapeutic potential in non-small cell lung cancers.

Keyword

HIF-1alpha; VEGF; EGCG; Lung cancer; Hypoxia

MeSH Terms

Actins
Anoxia
Carcinoma, Non-Small-Cell Lung
Catechin
Cell Culture Techniques
Cell Cycle
Cell Line
Humans
Lung
Lung Neoplasms
Neoplasm Metastasis
Oxygen
RNA, Messenger
Tea
Vascular Endothelial Growth Factor A
Actins
Catechin
Oxygen
RNA, Messenger
Tea
Vascular Endothelial Growth Factor A

Figure

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  Figure 1 Cell viability under normoxia and hypoxia; Under hypoxic conditions, the proliferation of A549 cells was decreased than under normoxic conditions (*p value<0.05).

• 

  Figure 2 Changes of hypoxia-induced HIF-1α messenger RNA transcription. (A) Epigallocatechin-3-gallate (EGCG) 12.5 µmol/L (B) EGCG 25.0 µmol/L (C) EGCG 50.0 µmol/L (D) EGCG 100.0 µmol/L; Under EGCG 50.0 and 100.0 µmol/L, expression of hypoxia-induced HIF-1α in A549 cells was decreased by EGCG.

• 

  Figure 3 Changes of hypoxia-induced VEGF messenger RNA transcription. (A) Epigallocatechin-3-gallate (EGCG) 12.5 µmol/L (B) EGCG 25.0µmol/L (C) EGCG 50.0 µmol/L (D) EGCG 100.0 µmol/L; Under any concentration of EGCG, expression of hypoxia-induced VEGF was not affected by EGCG in A549 cells (p>0.05).

• 

  Figure 4 Bar graphs for relative transcriptional levels of hypoxia-induced HIF-1α (A) and VEGF (B) in contrast to house-keeping β-actin mRNA level under various concentrations of Epigallocatechin-3-gallate (EGCG). These graphs summarized results of Figure 3(A) to (D) (*p<0.05 compared to control).

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