Malignant transformation of a mouse liver epithelial cell line by transfection of an activated c-H-ras gene with a point mutation at codon 12.
In order to scrutinize the reason why in mouse liver system only activated H-ras gene with a point mutation at codon 61 but not codon 12 is frequently seen although the latter mutation is highly frequent in methylnitrosourea-induced rat mammary tumors, transforming activity of these two types of mutated H-ras gene was investigated utilizing an immortalized but not fully transformed mouse liver epithelial cell line MLE-10, established in our laboratory. MLE-10 cells were transfected with activated human c-H-ras gene having a point mutation at either codon 12 (PT24) or 61 (PSK2), together with PSV2neo, or with PSV2neo only. G418 resistant colonies, propagated separately, gave rise to 6, 3 and 6 lines respectively. All the PT24 and PSK2-transfected cell lines were growth capable in both soft agar and nude mouse subcutis, with similar growth rate and morphological features whereas none of the cell lines transfected with the PSV2neo only revealed such growth capability. The results thus revealed that c-H-ras with a mutation at codon 12 has oncogenic activity to the mouse hepatocyte, although after immortalization, at the degree similar to the same gene with a mutation at codon 61.
Department of Pathology, Cancer Institute, Tokyo, Japan.
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Kanda
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Lee
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Nomura
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Ohtake
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Kitagawa
D000818:Animals; D015139:Blotting, Southern; D015153:Blotting, Western; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D003062:Codon / Q000235:genetics; D004848:Epithelium; D005786:Gene Expression Regulation; D011905:Genes, ras; D006801:Humans; D008099:Liver; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D017354:Point Mutation; D016283:Proto-Oncogene Proteins p21(ras) / Q000032:analysis; D051381:Rats; D015183:Restriction Mapping; D014162:Transfection
D003062:Codon; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)