title: Significance of calcium-sensing receptor expression in gastric cancer.
abstract: OBJECTIVE
  The calcium-sensing receptor (CaSR) is known to have differential expression in various carcinomas and normal tissues. It has been shown to be involved in carcinogenesis or tumor suppression. However, its role in gastric cancer remains unknown. This study was performed to determine the CaSR expression level in gastric cancer and non-tumor gastric tissues and to examine the related clinicopathological factors.
  
  
  METHODS
  Thirty-one pairs of gastric cancer tissues and matched non-tumor gastric tissues were obtained from surgical tissues after gastrectomy. Using real-time polymerase chain reaction, we measured CaSR mRNA expression. We evaluated the association between CaSR mRNA expression and clinicopathological variables based on the downregulation or upregulation of CaSR mRNA expression in gastric cancer tissues compared to those of matched non-tumor gastric tissues. By immunohistochemistry, we confirmed CaSR expression levels in gastric cancer tissues.
  
  
  RESULTS
  Downregulation of CaSR mRNA was observed in 77.4% of gastric cancer tissues compared to their matched normal tissues. Downregulated CaSR was associated with a tendency for deeper invasion into the proper muscle (p = 0.028) and more advanced stage (II-IV; p = 0.012).
  
  
  CONCLUSIONS
  We conclude that downregulation of CaSR may contribute to the prevention or suppression of tumor outgrowth.
authors.affiliation: a 1 Department of Health Promotion Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Chung Hyun
authors.initials: CH
authors.lastname: Tae
authors.affiliation: b 2 Department of Internal Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Ki-Nam
authors.initials: KN
authors.lastname: Shim
authors.affiliation: b 2 Department of Internal Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Hye In
authors.initials: HI
authors.lastname: Kim
authors.affiliation: b 2 Department of Internal Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Yang-Hee
authors.initials: YH
authors.lastname: Joo
authors.affiliation: c 3 Department of Surgery, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Joo-Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: d 4 Department of Pathology, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Min-Sun
authors.initials: MS
authors.lastname: Cho
authors.affiliation: b 2 Department of Internal Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Chang Mo
authors.initials: CM
authors.lastname: Moon
authors.affiliation: b 2 Department of Internal Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Seong-Eun
authors.initials: SE
authors.lastname: Kim
authors.affiliation: b 2 Department of Internal Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Hye-Kyung
authors.initials: HK
authors.lastname: Jung
authors.affiliation: b 2 Department of Internal Medicine, Ewha Womans University School of Medicine, Ewha Medical Research Institute , Seoul, Korea.
authors.forename: Sung-Ae
authors.initials: SA
authors.lastname: Jung
mesh_terms: D014408:Biomarkers, Tumor; D015536:Down-Regulation; D005743:Gastrectomy; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D044169:Receptors, Calcium-Sensing / Q000235:genetics / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; C095550:CASR protein, human; D012333:RNA, Messenger; D044169:Receptors, Calcium-Sensing
keywords: calcium-sensing receptor; gastric cancer; tumor markers; tumor suppression