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Detection of K‐ ras mutations in stools of patients with colorectal cancer by mutant‐enriched PCR
Author(s) -
Nollau Peter,
Moser Carsten,
Weinland Günter,
Wagener Christoph
Publication year - 1996
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19960503)66:3<332::aid-ijc11>3.0.co;2-d
Subject(s) - mutation , colorectal cancer , lymphoma , mutant , cancer , biology , gene , polymerase chain reaction , microbiology and biotechnology , genetics , immunology
Abstract Mutant‐enriched PCR was applied to the detection of mutations at codons 12 and 13 of K‐ ras genes in the stools of patients with colorectal cancer. Mutations were analyzed in stool samples obtained prior to surgery. Resected tumor specimens were screened for K‐ ras mutations by PCR‐mediated RFLP analysis. Using normal stool samples, assay conditions were adjusted to optimal sensitivity and specificity. The following specimens were included in the study: 16 stool samples corresponding to carcinomas in which K‐ ras mutations had been identified; 7 randomly selected stool samples corresponding to carcinomas which were negative for K‐ ras mutations; 1 stool sample from a patient with non‐Hodgkin's lymphoma. In 13 of the 16 stool samples (81%) corresponding to tumors in which K‐ ras mutations had been identified previously, K‐ ras mutations were detected. In 2 of the 7 stool samples corresponding to tumors in which K‐ ras mutations had not been detected by previous PCR‐mediated RFLP analysis, K‐ ras mutations were also present. Reanalyses of the tumors corresponding to these 2 positive stool samples by mutant‐enriched PCR revealed a K‐ ras mutation in one of the tumors. The stool and tumor of the patient with non‐Hodgkin's lymphoma were negative for K‐ ras mutations. DNA sequence analysis revealed that, for each of the K‐ ras mutations identified in stool samples, identical base substitutions were present in the corresponding tumor tissue. The results indicate that tumor cells harboring K‐ ras mutations can be detected in the stools of patients with colorectal cancer by mutant‐enriched PCR with high sensitivity and specificity. Because of the simplicity of the technique, it may be suitable for screening of stool samples for mutations of the K‐ ras gene. © 1996 Wiley‐Liss, Inc.