Genes Chromosomes Cancer  1992 Sep;5(2):109-18 

Detection of RAS mutations in archival testicular germ cell tumors by polymerase
chain reaction and oligonucleotide hybridization.

Moul JW, Theune SM, Chang EH.

Department of Surgery, Uniformed Services University of the Health Sciences,
Bethesda, Maryland 20814-4799.

Preliminary studies of RAS mutational activation in human testicular germ cell
neoplasms have yielded conflicting results. Whereas two studies of clinical
material revealed a significant incidence of N- and KRAS mutations, two studies
of a variety of germ cell lines failed to document RAS mutations. To clarify the
incidence of RAS mutations in these tumors, we studied archival
paraffin-embedded, formalin-fixed orchiectomy specimens from 25 nonseminomas
(NSGCT), 18 seminomas (SEM), and one Leydig cell tumor. For 14 of the 44
neoplasms, DNA was also available from nonmalignant testis adjacent to the
tumor. Six age-matched patients had testes removed because of nonmalignant
disease and were studied as controls. Polymerase chain reaction (PCR) amplified
the K-, N-, and HRAS 12, 13, and 61 codons of these specimens, and mutations
were detected with mutation-specific oligonucleotide probe hybridization of
Southern and slot blots. Four mutations were found in KRAS 12 (4/44;[9.1%]). One
seminoma [1/18(5.6%)] contained the mutation GGT(GLY)----CGT(ARG), and three
NSGCT [3/25(12%)] were found to have GGT(GLY)----GAT(ASP) mutations. One of the
NSGCT mutations was detected in adjacent nonmalignant tissue, but the
corresponding tumor did not contain any detectable mutation. No mutations were
detected at KRAS 13 or 61, in NRAS or HRAS 12, 13, or 61, or in the control
normal testes. PCR, slot blots, and hybridizations were performed twice by two
separate investigators for confirmation of results. PCR-generated
mutation-specific positive controls were created for all possible RAS mutations,
and these along with wild-type DNA controls were integral to interpretation of
the oligonucleotide mismatch hybridization assay. By using positive and negative
controls, we have detected a relatively low incidence of RAS mutations in
archival human testicular germ cell tumors.

PMID: 1381946 [PubMed - indexed for MEDLINE]