Increased c-Ki- ras expression in hamster lung exposed to N-nitrosodiethylamine and hyperoxia as detected by the polymerase chain reaction

• Published in: Cancer letters Vol. 59; no. 1; pp. 75 - 80
• Main Authors: Ning, H., Oreffo, V.I.C., Gumerlock, P.H., Witschi, H.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 26.07.1991; Elsevier
• Subjects: Animal tumors. Experimental tumors; Animals; Base Sequence; Biological and medical sciences; c-Ki- ras; Cricetinae; Diethylnitrosamine - pharmacology; Endocrine System Diseases - chemically induced; Endocrine System Diseases - genetics; Eosine Yellowish-(YS); Experimental respiratory system tumors; formula omitted; Gene Expression; Genes, ras - genetics; hamster lung; Hematoxylin; Histocytochemistry; hyperoxia; Lung - drug effects; Lung - physiology; Lung Neoplasms - chemically induced; Lung Neoplasms - genetics; Male; Medical sciences; Mesocricetus; Molecular Sequence Data; N-nitrosodiethylamine; Neoplasms, Experimental - chemically induced; Neoplasms, Experimental - genetics; Nervous System Neoplasms - chemically induced; Nervous System Neoplasms - genetics; Oxygen - pharmacology; Polymerase Chain Reaction; RAS; RNA - analysis; RNA - genetics; Tumors; RNA PCR; hamster lung; N-nitrosodiethylamine; hyperoxia; RAS; c-Ki- ras; Lung; Rodentia; Malignant tumor; Gene expression; Bronchopulmonary; Polymerase chain reaction; Vertebrata; Mammalia; Messenger RNA; Animal; C-Onc gene; Hyperoxia; Neuroendocrine tumor; Hamster
• ISSN: 0304-3835; 1872-7980
• DOI: 10.1016/0304-3835(91)90138-8

Neuroendocrine lung cancers can be induced in hamsters within 8–12 weeks by combined exposure to N-nitrosodiethylamine (DEN) and hyperoxia. The expression of the c-Ki- ras gene in this lung cancer model was studied using polymerase chain reaction analysis of mRNA ( RNA PCR ). We used four different groups of hamsters, exposed for 6 weeks to DEN with hyperoxia (60% oxygen), DEN, hyperoxia, or ambient air, respectively. Total RNA was isolated from lung tissues and cDNA made prior to PCR amplification. A 234-bp product was amplified from c-Ki- ras cDNA and quantitated using scanning laser densitometry. The data obtained were normalized to the expression of the house keeping gene B-actin. The c-Ki- ras products were present after amplification of all hamster lung RNA samples. The hamster lungs exposed to DEN with hyperoxia displayed higher c-Ki- ras protooncogene expression than hamsters exposed to DEN, hyperoxia, or ambient air alone. Since the animals studied were sacrificed at 6 weeks, prior to the appearance of tumors, we conclude that this increased expression may indicate a role for c-Ki- ras in the initial steps in malignant transformation of neuroendocrine cells.