Open AccessGermline PMS 2 mutation screened by mismatch repair protein immunohistochemistry of colorectal cancer in Japan
Author(s) -
Sugano Kokichi,
Nakajima Takeshi,
Sekine Shigeki,
Taniguchi Hirokazu,
Saito Shinya,
Takahashi Masahiro,
Ushiama Mineko,
Sakamoto Hiromi,
Yoshida Teruhiko
Publication year - 2016
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/cas.13073
Subject(s) - multiplex ligation dependent probe amplification , colorectal cancer , biology , microbiology and biotechnology , frameshift mutation , germline mutation , cancer , germline , mutation , exon , genetics , gene , cancer research , medicine
Germline PMS 2 gene mutations were detected by RT ‐ PCR /direct sequencing of total RNA extracted from puromycin‐treated peripheral blood lymphocytes ( PBL ) and multiplex ligation‐dependent probe amplification ( MLPA ) analyses of Japanese patients with colorectal cancer ( CRC ) fulfilling either the revised Bethesda Guidelines or being an age at disease onset of younger than 70 years, and screened by mismatch repair protein immunohistochemistry of formalin‐fixed paraffin embedded sections. Of the 501 subjects examined, 7 (1.40%) showed the downregulated expression of the PMS 2 protein alone and were referred to the genetic counseling clinic. Germline PMS 2 mutations were detected in 6 (85.7%), including 3 nonsense and 1 frameshift mutations by RT ‐ PCR /direct sequencing and 2 genomic deletions by MLPA . No mutations were identified in the other MMR genes (i.e. MSH 2 , MLH 1 and MSH 6 ). The prevalence of the downregulated expression of the PMS 2 protein alone was 1.40% among the subjects examined and IHC results predicted the presence of PMS 2 germline mutations. RT ‐ PCR from puromycin‐treated PBL and MLPA may be employed as the first screening step to detect PMS 2 mutations without pseudogene interference, followed by the long‐range PCR /nested PCR validation using genomic DNA .