title: Connexin evolution ameliorates the risk of various cancers.
abstract: OBJECTIVE
  Connexins can affect many cancers, but the relationship of many connexins is confused and the functions in cancers are unknown.
  
  
  METHODS
  With conservative domains of connexins, the phylogenetic tree was constructed and all connexins could be divided into five groups (I, II, III, IV and V). The clock analysis showed that group V appeared earlier than group IV, which was earlier than group III, which was earlier than group I and II in the evolution. Group I involves in colorectal, lung, breast, pancreatic, gastric, colon, bladder and ovarian cancers. Group II affects bladder, breast, lung, gastric, colorectal, prostate, esophageal, renal, head and neck cancers. Group III affects bladder and breast cancer. The function of group IV and V has not been reported.
  
  
  RESULTS
  When HT1376 bladder cancer cells were transfected with Cx31.9 (Group IV), the growth rate was inhibited by 17%. Inversely, when HT1376 cells were transfected with Cx31.9 RNAi, the growth rate was increased by 21%. For Cx23 (Group V), it could not affect the growth rate.
  
  
  CONCLUSIONS
  The results suggested that ancient connexins did not involve in cancers. Recent connexins have developed the functions for inhibiting the progression of cancers in the evolution.
authors.affiliation: Department of Urology, Kunming General Hospital of Chengdu Military Command, Kunming, China. zhansongzhoucq@163.com.
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.forename: K
authors.initials: K
authors.lastname: Dou
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D017630:Connexins / Q000235:genetics*; D006801:Humans; D009369:Neoplasms / Q000235:genetics*; D010802:Phylogeny; D012307:Risk Factors; D014714:Vertebrates
chemical_list: D017630:Connexins