Yeomyung Park

Publications (3)14.58 Total impact

• Article: Erratum to: Mammalian MST2 kinase and human Salvador activate and reduce estrogen receptor alpha in the absence of ligand.

  Yeomyung Park, Joonwoo Park, Yonghee Lee, Wonchung Lim, Byung-Chul Oh, Chanyoung Shin, Wansup Kim, Young Joo Lee
  Journal of Molecular Medicine 03/2012; 90(3):345. · 4.67 Impact Factor
• Source

  Available from: PubMed Central

  Article: Estrogen receptor beta inhibits transcriptional activity of hypoxia inducible factor-1 through the downregulation of arylhydrocarbon receptor nuclear translocator.

  Wonchung Lim, Yeomyung Park, Jungyoon Cho, Choa Park, Joonwoo Park, Young-Kwon Park, Hyunsung Park, Youngjoo Lee
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  ABSTRACT: Estrogen receptor (ER) β is predicted to play an important role in prevention of breast cancer development and metastasis. We have shown previously that ERβ inhibits hypoxia inducible factor (HIF)-1α mediated transcription, but the mechanism by which ERβ works to exert this effect is not understood. Vascular endothelial growth factor (VEGF) was measured in conditioned medium by enzyme-linked immunosorbent assays. Reverse transcription polymerase chain reaction (RT-PCR), Western blotting, immunoprecipitation, luciferase assays and chromatin immunoprecipitation (ChIP) assays were used to ascertain the implication of ERβ on HIF-1 function. In this study, we found that the inhibition of HIF-1 activity by ERβ expression was correlated with ERβ's ability to degrade aryl hydrocarbon receptor nuclear translocator (ARNT) via ubiquitination processes leading to the reduction of active HIF-1α/ARNT complexes. HIF-1 repression by ERβ was rescued by overexpression of ARNT as examined by hypoxia-responsive element (HRE)-driven luciferase assays. We show further that ERβ attenuated the hypoxic induction of VEGF mRNA by directly decreasing HIF-1α binding to the VEGF gene promoter. These results show that ERβ suppresses HIF-1α-mediated transcription via ARNT down-regulation, which may account for the tumour suppressive function of ERβ.
  Breast cancer research: BCR 03/2011; 13(2):R32. · 5.24 Impact Factor
• Article: Mammalian MST2 kinase and human Salvador activate and reduce estrogen receptor alpha in the absence of ligand.

  Yeomyung Park, Joonwoo Park, Yonghee Lee, Wonchung Lim, Byung-Chul Oh, ChanYoung Shin, Wansup Kim, YoungJoo Lee
  [show abstract] [hide abstract]
  ABSTRACT: Mammalian MST2 kinase plays an important role in cell proliferation, survival, and apoptosis. In search of interacting proteins of MST2, we found that estrogen receptor α (ERα) co-immunoprecipitates with MST2 and its adaptor protein human Salvador (hSAV). Using reporter assays, we observed that overexpression of MST2 and hSAV leads to ligand-independent activation of ERα in human breast cancer MCF-7 cells, which was attenuated by the knockdown of hSAV. Furthermore, using truncated mutants of hSAV, we observed that the C terminus of hSAV is necessary and sufficient for the induction of ERα transactivation. The expression of hSAV and MST2 results in the phosphorylation of ERα at serine residues 118 and 167 and represses ERα expression. We then investigated the incidence of MST2 and ERα expression with other tumor biomarkers using commercially available tissue microarrays. Among 40 breast cancer samples analyzed, 60% (24 out of 40) expressed MST2. Nineteen among the 40 cases were MST2-positive and ERα-negative, implying a correlation between expressions of MST2 with loss of ERα in breast tumor samples. This study suggests that MST and hSAV act as novel co-regulators of ERα and may play an important role in breast cancer pathogenesis.
  Journal of Molecular Medicine 02/2011; 89(2):181-91. · 4.67 Impact Factor