Open AccessLoss or Somatic Mutations of hMSH2 Occur in Hereditary Nonpolyposis Colorectal Cancers with hMSH2 Germline Mutations
Author(s) -
Lu ShiLong,
Akiyama Yoshimitsu,
Nagasaki Hiromi,
Nomizu Tadashi,
Ikeda Eiichi,
Baba Shozo,
Ushio Kyosuke,
Iwama Takeo,
Maruyama Kazuo,
Yuasa Yasuhito
Publication year - 1996
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1996.tb00218.x
Subject(s) - dna mismatch repair , germline mutation , frameshift mutation , genetics , loss of heterozygosity , biology , germline , microsatellite instability , mutation , carcinogenesis , genome instability , nonsense mutation , cancer research , gene , missense mutation , dna repair , allele , dna , microsatellite , dna damage
Hereditary nonpolyposis colorectal cancer (HNPCC) is a major cancer susceptibility syndrome known to be caused by the inheritance of mutations in DNA mismatch repair genes, such as hMSH2, hMLH1, hPMS1 and hPMS2 . To investigate the role of genetic alterations of hMSH2 in HNPCC tumorigenesis, we analyzed 36 Japanese HNPCC kindreds as to hMSH2 germline mutations. Moreover, we also examined somatic mutations of hMSH2 or loss of heterozygosity at or near the hMSH2 locus in the tumors from the hMSH2 ‐related kindreds. Germline mutations were detected in five HNPCC kindreds (5/36, 14%). Among them, three were nonsense mutations, one was a frameshift mutation and the other was a mutation in an intron where the mutation affected splicing. Loss of heterozygosity in four and somatic mutations in one were detected among the eight tumors with hMSH2 germline mutations. All these alterations were only detected in genomic instability(+) tumors, i.e., not in genomic instability(‐) ones, indicating that mutations of hMSH2 were responsible for at least some of the tumors with genomic instability. These data establish a basis for the presymptomatic diagnosis of HNPCC patients, and constitute further evidence that both DNA mismatch repair genes and tumor suppressor genes may share the same requirement, i.e., two hits are necessary to inactivate the gene function.