Alterations of the LKB1 gene in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine in rats.
OBJECTIVE
Germ line mutations of the LKB1 gene cause the autosomal dominant Peutz-Jeghers syndrome (PJS), and PJS has also been associated with an increased risk of developing cancers, suggesting LKB1 may act as a tumor suppressor in PJS. By contrast, LKB1 mutations are rare events in most sporadic tumors in non-PJS patients, except for lung cancers. To better understand the involvement of LKB1 gene alterations during lung carcinogenesis, we investigated the LKB1 gene mutations and expressions in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats.


METHODS
Male Wistar rats, 6 weeks old, were given 2,000 ppm BHP in their drinking water for 12 weeks and maintained without further treatment until they were sacrificed at 25 weeks. A total of 15 lung adenocarcinomas were obtained, and genomic DNA was extracted for the search of mutations using polymerase chain reaction (PCR)-single strand conformation polymorphism analysis. To assess altered expressions of the LKB1 gene, reverse transcription-PCR analysis was also performed.


RESULTS
No mutations were found throughout exons 1-9 in any of the tumors. Aberrant transcripts bearing deletions of nucleotides 216-1459, 289-1302, 268-1261, or 257-1378 were detected in 5 of 15 adenocarcinomas (33.3%).


CONCLUSIONS
These results suggest that alterations of the LKB1 gene might be involved in the development of lung adenocarcinomas induced by BHP in rats.
Tajiri
Masaki
M
Laboratory of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, Higashiosaka, Japan.
Wakabayashi
Naoko
N
Tsujino
Megumu
M
Fujii
Minako
M
Okabe
Kyoko
K
Honoki
Kanya
K
Tsujiuchi
Toshifumi
T
D000091162:AMP-Activated Protein Kinase Kinases; D000230:Adenocarcinoma / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D002289:Carcinoma, Non-Small-Cell Lung / Q000139:chemically induced / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D008297:Male; D009154:Mutation / Q000187:drug effects; D009602:Nitrosamines; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar
D009602:Nitrosamines; C012457:diisopropanolnitrosamine; D017346:Protein Serine-Threonine Kinases; C488755:Stk11 protein, rat; D000091162:AMP-Activated Protein Kinase Kinases