title: Galectin-3-independent Down-regulation of GABABR1 due to Treatment with Korean Herbal Extract HAD-B Reduces Proliferation of Human Colon Cancer Cells.
abstract: OBJECTIVE
  Many efforts have shown multi-oncologic roles of galectin-3 for cell proliferation, angiogenesis, and apoptosis. However, the mechanisms by which galectin-3 is involved in cell proliferation are not yet fully understood, especially in human colon cancer cells.
  
  
  METHODS
  To cluster genes showing positively or negatively correlated expression with galectin-3, we employed human colon cancer cell lines, SNU-61, SNU-81, SNU-769B, SNU-C4 and SNU-C5 in high-throughput gene expression profiling. Gene and protein expression levels were determined by using real-time quantitative polymerase chain reaction (PCR) and western blot analysis, respectively. The proliferation rate of human colon cancer cells was measured by using a 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay.
  
  
  RESULTS
  Expression of γ-aminobutyric acid B receptor 1 (GABABR1) showed a positive correlation with galectin-3 at both the transcriptional and the translational levels. Downregulation of galectin-3 decreased not only GABABR1 expression but also the proliferation rate of human colon cancer cells. However, Korean herbal extract, HangAmDan-B (HAD-B), decreased expression of GABABR1 without any expressional change of galectin-3, and offset γ-aminobutyric acid (GABA)-enhanced human colon cancer cell proliferation.
  
  
  CONCLUSIONS
  Our present study confirmed that GABABR1 expression was regulated by galectin-3. HAD-B induced galectin-3-independent down-regulation of GABABR1, which resulted in a decreased proliferation of human colon cancer cells. The therapeutic effect of HAD-B for the treatment of human colon cancer needs to be further validated.
authors.affiliation: Research Institute, National Cancer Center, Goyang, Korea ; Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Kim
authors.affiliation: East-West Cancer Center, Dunsan Oriental Hospital of Daejeon University, Daejeon, Korea.
authors.forename: Yong-Kyun
authors.initials: YK
authors.lastname: Kwon
authors.affiliation: East-West Cancer Center, Dunsan Oriental Hospital of Daejeon University, Daejeon, Korea.
authors.forename: Chong-Kwan
authors.initials: CK
authors.lastname: Cho
authors.affiliation: East-West Cancer Center, Dunsan Oriental Hospital of Daejeon University, Daejeon, Korea.
authors.forename: Yeon-Weol
authors.initials: YW
authors.lastname: Lee
authors.affiliation: Research Institute, National Cancer Center, Goyang, Korea.
authors.forename: So-Hyun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Research Institute, National Cancer Center, Goyang, Korea ; Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sang-Geun
authors.initials: SG
authors.lastname: Jang
authors.affiliation: Research Institute, National Cancer Center, Goyang, Korea.
authors.forename: Byong-Chul
authors.initials: BC
authors.lastname: Yoo
authors.affiliation: East-West Cancer Center, Dunsan Oriental Hospital of Daejeon University, Daejeon, Korea.
authors.forename: Hwa-Seong
authors.initials: HS
authors.lastname: Yoo
keywords: 5-fluorouracil; GABABR1; HAD-B; galectin-3; human colon cancer; proliferation