title: Prognostic value of carbonic anhydrase VII expression in colorectal carcinoma.
abstract: BACKGROUND
  Carbonic anhydrases (CAs) have been implicated in the pathogenesis of human cancers. Carbonic anhydrase VII (CA7), a member of the CA gene family, was recently demonstrated to be expressed in several human tissues including colon. Nevertheless, the expression and clinical relevance of CA7 in colorectal carcinoma (CRC) has not been investigated.
  
  
  METHODS
  Real-time PCR, western blot, and immunohistochemistry analyses were used to determine CA7 expression in CRC clinical samples. The correlation of CA7 expression with clinicopathologic features was assessed in 228 patients from Luoyang, China (training cohort) and validated in 151 patients from Shanghai, China (validation cohort). Kaplan-Meier and Cox proportional regression analyses were used to estimate the association between CA7 expression and patients' survival.
  
  
  RESULTS
  CA7 expression was frequently downregulated in CRC tissues at both the mRNA and protein levels. Reduced expression of CA7 was significantly correlated with poor differentiation, positive lymph node metastasis, advanced TNM stage and unfavorable clinical outcome not only in the training cohort but also in the validation set. Survival analysis indicated that patients with lower CA7 expression had a significantly shorter disease-specific survival (DSS) than those with higher CA7 expression. Importantly, further stage-based analyses revealed that decreased CA7 expression significantly predicted poor DSS and was an independent adverse prognostic indicator for patients with early stage tumors in both cohorts.
  
  
  CONCLUSIONS
  Our results indicate that decreased expression of CA7 correlates with disease progression and predicts poor prognosis in CRC, especially for patients with early stage tumors.
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. guangzyang@163.com.|Department of Clinical Laboratory, 150th Hospital of PLA, Luoyang, China. guangzyang@163.com.
authors.forename: Guang-Zhen
authors.initials: GZ
authors.lastname: Yang
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. lhu@outlook.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Colorectal Surgery, 150th Hospital of PLA, Luoyang, China. jiancai150@yeah.net.
authors.forename: Jian
authors.initials: J
authors.lastname: Cai
authors.affiliation: Department of Oncology, 150th Hospital of PLA, Luoyang, China. chenocean@163.com.
authors.forename: Hai-Yang
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. yuzhang150@126.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Oncology, Changhai Hospital, Second Military Medical University, Shanghai, China. fengdanlh@126.com.
authors.forename: Dan
authors.initials: D
authors.lastname: Feng
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. chenye_qi@163.com.
authors.forename: Chen-Ye
authors.initials: CY
authors.lastname: Qi
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. yanxiazai@163.com.
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Zhai
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. hui_gong@yeah.net.
authors.forename: Hui
authors.initials: H
authors.lastname: Gong
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. fuhao_150@163.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Fu
authors.affiliation: Department of Gastrointestine Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China. caiqingpingwcwk@163.com.
authors.forename: Qing-Ping
authors.initials: QP
authors.lastname: Cai
authors.affiliation: Anal-Colorectal Surgery Institute, 150th Hospital of PLA, Luoyang, China. chunfgao@163.com.
authors.forename: Chun-Fang
authors.initials: CF
authors.lastname: Gao
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D002256:Carbonic Anhydrases / Q000096:biosynthesis* / Q000235:genetics; D002681:China; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012333:RNA, Messenger / Q000096:biosynthesis
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D002256:Carbonic Anhydrases; C477051:carbonic anhydrase VI