title: Response gene to complement-32 enhances metastatic phenotype by mediating transforming growth factor beta-induced epithelial-mesenchymal transition in human pancreatic cancer cell line BxPC-3.
abstract: BACKGROUND
  Response gene to complement-32 (RGC-32) is comprehensively expressed in many kinds of tissues and has been reported to be expressed abnormally in different kinds of human tumors. However, the role of RGC-32 in cancer remains controversial and no reports have described the effect of RGC-32 in pancreatic cancer. The present study investigated the expression of RGC-32 in pancreatic cancer tissues and explored the role of RGC-32 in transforming growth factor-beta (TGF-β)-induced epithelial-mesenchymal transition (EMT) in human pancreatic cancer cell line BxPC-3.
  
  
  METHODS
  Immunohistochemical staining of RGC-32 and E-cadherin was performed on specimens from 42 patients with pancreatic cancer, 12 with chronic pancreatitis and 8 with normal pancreas. To evaluate the role of RGC-32 in TGF-β-induced EMT in pancreatic cancer cells, BxPC-3 cells were treated with TGF-β1, and RGC-32 siRNA silencing and gene overexpression were performed as well. The mRNA expression and protein expression of RGC-32 and EMT markers such E-cadherin and vimentin were determined by quantitative reverse transcription-PCR (qRT-PCR) and western blot respectively. Finally, migration ability of BxPC-3 cells treated with TGF-β and RGC-32 siRNA transfection was examined by transwell cell migration assay.
  
  
  RESULTS
  We found stronger expression of RGC-32 and higher abnormal expression rate of E-cadherin in pancreatic cancer tissues than those in chronic pancreatitis tissues and normal pancreatic tissues. Immunohistochemical analysis revealed that both RGC-32 positive expression and E-cadherin abnormal expression in pancreatic cancer were correlated with lymph node metastasis and TNM staging. In addition, a significant and positive correlation was found between positive expression of RGC-32 and abnormal expression of E-cadherin. Furthermore, in vitro, we found sustained TGF-β stimuli induced EMT and up-regulated RGC-32 expression in BxPC-3 cells. By means of siRNA silencing and gene overexpression, we further demonstrated that RGC-32 mediated TGF-β-induced EMT and migration in BxPC-3 cells.
  
  
  CONCLUSIONS
  The results above indicated that RGC-32 might be a novel metastasis promoting gene in pancreatic cancer and it enhances metastatic phenotype by mediating TGF-β-induced EMT in human pancreatic cancer cell line BxPC-3.
authors.affiliation: Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
authors.forename: Hua
authors.initials: H
authors.lastname: Qin
authors.forename: Pei-Yuan
authors.initials: PY
authors.lastname: Li
authors.forename: Sheng-Nan
authors.initials: SN
authors.lastname: Xu
authors.forename: Hui-Fang
authors.initials: HF
authors.lastname: Pang
authors.forename: Hui-Zhen
authors.initials: HZ
authors.lastname: Zhao
authors.forename: De-Min
authors.initials: DM
authors.lastname: Li
authors.forename: Qiu
authors.initials: Q
authors.lastname: Zhao
mesh_terms: D015820:Cadherins / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D009124:Muscle Proteins / Q000235:genetics*; D009362:Neoplasm Metastasis / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology*; D010641:Phenotype; D034622:RNA Interference; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: D015820:Cadherins; D018797:Cell Cycle Proteins; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; C115049:RGCC protein, human; D016212:Transforming Growth Factor beta