title: Overexpression of B2M and loss of ALK7 expression are associated with invasion, metastasis, and poor-prognosis of the pancreatic ductal adenocarcinoma.
abstract: BACKGROUND
  Approximately 80% of patients with pancreatic ductal adenocarcinoma (PDAC) have metastatic disease with poor prognosis, but clinically available markers have not yet been identified.
  
  
  OBJECTIVE
  In this study, we investigated the expression of B2M and ALK7 in 106 PDACs compared to precursor lesions of the pancreas.
  
  
  METHODS
  Immunohistochemistry was used to detect B2M and ALK7 protein expression.
  
  
  RESULTS
  Positive B2M expression was significantly higher, while positive expression of ALK7 was significantly lower in PDAC than in precursor lesions (p < 0.01 or p < 0.001). Positive B2M expression was also significantly higher, while positive ALK7 expression was significantly lower in cases with well-differentiated adenocarcinoma, small tumor mass, no-metastasis of the lymph node, no-invasion of regional tissues, and TNM I or II stage disease than in cases having poorly-differentiated adenocarcinoma, large tumor mass, with metastasis and invasion, and TNM stage III or IV stage disease (p < 0.01). Univariate Kaplan-Meier analysis showed that B2M overexpression (p < 0.001), but lack of ALK7 expression (p < 0.001) was significantly associated with shorter overall survival. Cox multivariate analysis showed that differentiation, tumor mass, lymph node metastasis, invasion, TNM stage, and B2M levels negatively correlated with overall survival. In contrast, ALK7 level positively correlated with overall survival. Positive B2M and negative ALK7 expression are poor prognostic factors in PDAC patients.
  
  
  CONCLUSIONS
  B2M and ALK7 might be important biological markers involved in the carcinogenesis, metastasis, invasion, and prognosis of PDAC.
authors.affiliation: Research Laboratory of Hepatobiliary Diseases, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Liu
authors.affiliation: Research Laboratory of Hepatobiliary Diseases, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Zhulin
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Pathology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Daiqiang
authors.initials: D
authors.lastname: Li
authors.affiliation: Research Laboratory of Hepatobiliary Diseases, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Ziru
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Research Laboratory of Hepatobiliary Diseases, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Xiongying
authors.initials: X
authors.lastname: Miao
authors.affiliation: Research Laboratory of Hepatobiliary Diseases, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Leping
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Pathology, Third Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zou
authors.affiliation: Department of Pathology, Third Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
mesh_terms: D030201:Activin Receptors, Type I / Q000378:metabolism*; D000230:Adenocarcinoma / Q000378:metabolism / Q000556:secondary* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000378:metabolism*; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000556:secondary* / Q000601:surgery; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010179:Pancreas / Q000378:metabolism / Q000473:pathology*; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D015996:Survival Rate; D001613:beta 2-Microglobulin / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D001613:beta 2-Microglobulin; C424205:ACVR1C protein, human; D030201:Activin Receptors, Type I
keywords: ALK7; B2M; Pancreatic ductal adenocarcinoma; immunohistochemistry