title: Expression and significance of Musashi-1 in gastric cancer and precancerous lesions.
abstract: OBJECTIVE
  To investigate expression of stem cell marker Musashi-1 (Msi-1) in relationship to tumorigenesis and progression of intestinal-type gastric cancer (GC).
  
  
  METHODS
  Endoscopic biopsy specimens and surgical specimens were obtained, including 54 cases of intestinal-type GC, 41 high-grade intraepithelial neoplasia, 57 low-grade intraepithelial neoplasia, 31 intestinal metaplasia, and 36 normal gastric mucosa. Specimens were fixed in 10% paraformaldehyde, conventionally dehydrated, embedded in paraffin, and sliced in 4-μm-thick serial sections. Two-step immunohistochemical staining was used to detect Msi-1 and proliferating cell nuclear antigen (PCNA) expression. Correlation analysis was conducted between Msi-1 and PCNA expression. The relationship between Msi-1 expression and clinicopathological parameters of GC was analyzed statistically.
  
  
  RESULTS
  There were significant differences in Msi-1 and PCNA expression in different pathological tissues (χ² = 15.37, P < 0.01; χ² = 115.36, P < 0.01). Msi-1 and PCNA-positive cells were restricted to the isthmus of normal gastric glands. Expression levels of Msi-1 and PCNA in intestinal metaplasia were significantly higher than in normal mucosa (U = 392.0, P < 0.05; U = 40.50, P < 0.01), whereas there was no significant difference compared to low or high-grade intraepithelial neoplasia. Msi-1 and PCNA expression in intestinal-type GC was higher than in high-grade intraepithelial neoplasia (U = 798.0, P < 0.05; U = 688.0, P < 0.01). There was a significantly positive correlation between Msi-1 and PCNA expression (r(s) = 0.20, P < 0.01). Msi-1 expression in GC tissues was correlated with their lymph node metastasis and tumor node metastasis stage (χ² = 12.62, P < 0.01; χ² = 11.24, P < 0.05), but not with depth of invasion and the presence of distant metastasis.
  
  
  CONCLUSIONS
  Msi-1-positive cells may play a key role in the early events of gastric carcinogenesis and may be involved in invasion and metastasis of GC.
authors.affiliation: Rong-Guang Kuang, Jian-Wen Wang, Department of Health Care, Qianfoshan Hospital Affiliated to Shandong University, Jinan 250014, Shandong Province, China.
authors.forename: Rong-Guang
authors.initials: RG
authors.lastname: Kuang
authors.forename: Yan
authors.initials: Y
authors.lastname: Kuang
authors.forename: Qing-Feng
authors.initials: QF
authors.lastname: Luo
authors.forename: Cheng-Jun
authors.initials: CJ
authors.lastname: Zhou
authors.forename: Rui
authors.initials: R
authors.lastname: Ji
authors.forename: Jian-Wen
authors.initials: JW
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D002278:Carcinoma in Situ / Q000737:chemistry* / Q000473:pathology; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000737:chemistry* / Q000473:pathology; D016009:Chi-Square Distribution; D018450:Disease Progression; D005260:Female; D005773:Gastroscopy; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D014411:Neoplastic Stem Cells / Q000737:chemistry* / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000032:analysis*; D011230:Precancerous Conditions / Q000737:chemistry* / Q000473:pathology; D011379:Prognosis; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D016601:RNA-Binding Proteins / Q000032:analysis*; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C491297:MSI1 protein, human; D009419:Nerve Tissue Proteins; D018809:Proliferating Cell Nuclear Antigen; D016601:RNA-Binding Proteins
keywords: Gastric cancer; Immunohistochemistry.; Musashi-1; Precancerous lesions; Stem cells