title: Loss of heterozygosity of chromosome 20 in sporadic colorectal cancer.
abstract: OBJECTIVE
  To analyze the loss of heterozygosity (LOH) of chromosome 20 in patients with sporadic colorectal cancer to identify additional loci involved in colorectal tumorigenesis.
  
  
  METHODS
  Polymorphic microsatellite markers were analyzed in 83 colorectal cancer patients' tumor and normal DNA by PCR. PCR products were electrophoresed on an 377 DNA sequencer. Genescan 2.1 and Genotype 2.1 software were used in the LOH scanning and analysis. Comparisons between LOH frequency and clinicopathological data were performed by chi(2) test. P < 0.05 was considered statistically significant.
  
  
  RESULTS
  The average LOH frequency in the long arm, short arm and whole chromosome 20 was 21.1%, 26.7% and 22.8%, respectively. Chromosome 20 exhibited relatively high LOH frequency, particularly in the regions of 20p and 20q11.1-q13.1.
  
  
  CONCLUSIONS
  There is notable genetic instability on chromosome 20 in sporadic colorectal carcinoma patients; that is, mutation on chromosome 20 is closely associated with sporadic colorectal carcinogenesis. Also, there may be tumor suppressor genes related to sporadic colorectal carcinoma near the region 20q11.1-q13.1.
authors.affiliation: Department of General Surgery, Shanghai No. 1 People's Hospital, 85 Wujing Road, Shanghai 200080, China. pengpzhb@online.sh.cn
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Peng
authors.forename: Chongzhi
authors.initials: C
authors.lastname: Zhou
authors.forename: Fang
authors.initials: F
authors.lastname: Zhang
authors.forename: Yun
authors.initials: Y
authors.lastname: Ling
authors.forename: Huamei
authors.initials: H
authors.lastname: Tang
authors.forename: Shaochun
authors.initials: S
authors.lastname: Bai
authors.forename: Wanqing
authors.initials: W
authors.lastname: Liu
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Qiu
authors.forename: Lin
authors.initials: L
authors.lastname: He
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002890:Chromosomes, Human, Pair 20; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged