[Studies on ras P21 expression and mutation at 12th codon of C-Ha-ras oncogene in squamous cell carcinoma of the larynx].
Monoclonal antibody directed against the ras oncogene product P21 was used to evaluate P21 expression in 42 cases of tumors of the larynx. The results showed that there was a higher level of ras P21 expression in squamous cell carcinoma of the larynx (LSCC) than in papilloma of the larynx (LP) and the normal tissues adjacent to LSCC, P < 0.05. We had also detected G-->T mutation at codon 12 of Ha-ras oncogenes in LSCC using polymerase chain reaction (PCR). PCR products were hybridized with mutation-specific oligonucleotide probes. Thirty per cent (6/20) LSCC cases harbored this mutation. But G-->T mutation was absent in 3 LP and 5 normal tissues adjacent to LSCC. A relationship may exist between the presence of G-->T mutation and Jakobsson's malignant grading result. All of 6 LSCC cases containing G-->T mutation were in high malignant grading group, P < 0.05. This study implicates that overexpression of ras P21 and presence of Ha-ras G-->T mutation may be one of the molecular mechanisms of maintenance of malignancy and progression of LSCC.
Yang
Q
Q
First Affiliated Hospital of Hubei Medical College, Wuhan.
D001483:Base Sequence; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism; D003062:Codon / Q000235:genetics; D004273:DNA, Neoplasm / Q000032:analysis; D015870:Gene Expression; D011905:Genes, ras; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D015689:Oncogene Protein p21(ras) / Q000378:metabolism*; D017354:Point Mutation; D016133:Polymerase Chain Reaction
D003062:Codon; D004273:DNA, Neoplasm; D015689:Oncogene Protein p21(ras)