Loss of heterozygosity of chromosome 20 in sporadic colorectal cancer.
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.
Peng
Zhihai
Z
Department of General Surgery, Shanghai No. 1 People's Hospital, 85 Wujing Road, Shanghai 200080, China. pengpzhb@online.sh.cn
Zhou
Chongzhi
C
Zhang
Fang
F
Ling
Yun
Y
Tang
Huamei
H
Bai
Shaochun
S
Liu
Wanqing
W
Qiu
Guoqiang
G
He
Lin
L
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