Presence of a modifier gene(s) affecting early renal carcinogenesis in the Tsc2 mutant (Eker) rat model.
The Eker (Tsc2 mutant) rat model of renal carcinoma is an example of Mendelian dominantly inherited predisposition to a specific cancer. Effects of genetic background on renal carcinogenesis in the Eker rat model (Eker/Eker > Eker/BN strain) indicate the presence in the BN rat genome of a modifier gene(s) that suppresses tumorigenesis. The identification of such a modifier gene(s) might help clarify the diversity of tuberous sclerosis in humans. i) We found that preneoplastic lesions in 8-week-old F1 rats [(Eker x LE) and (Eker x BN)] were more numerous in the LE strain than in the BN strain although the difference was not large. ii) We next administered N-ethyl-N-nitrosourea (ENU; single injection, i.p.) at the age of 4 weeks to amplify the strain difference in tumorigenesis, as we had done in an earlier study to identify the predisposing gene. iii) This experiment was also done in BN congenic Eker rats to confirm the strain difference in tumorigenesis. Preneoplastic lesions were fewer in BN congenic rats than in Eker rats by a factor of 100. We used this ENU system to perform a backcross experiment [F1(Eker x BN) x Eker] and finally succeeded in mapping a new modifier locus on rat chromosome 5 (the LOD score of the D5Rat12 was 3.13).
Kikuchi
Yasushi
Y
Department of Experimental Pathology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.
Sudo
Akemi
A
Mitani
Hiroaki
H
Hino
Okio
O
D000477:Alkylating Agents / Q000008:administration & dosage; D000818:Animals; D002292:Carcinoma, Renal Cell / Q000139:chemically induced / Q000235:genetics / Q000473:pathology*; D002874:Chromosome Mapping; D033481:Chromosomes, Mammalian / Q000235:genetics; D003433:Crosses, Genetic; D005038:Ethylnitrosourea / Q000008:administration & dosage; D005260:Female; D016147:Genes, Tumor Suppressor; D005838:Genotype; D007274:Injections, Intraperitoneal; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007680:Kidney Neoplasms / Q000139:chemically induced / Q000235:genetics / Q000473:pathology*; D008126:Lod Score; D008297:Male; D018895:Microsatellite Repeats; D009154:Mutation; D011230:Precancerous Conditions / Q000235:genetics / Q000473:pathology; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D020318:Rats, Long-Evans; D011922:Rats, Mutant Strains; D012097:Repressor Proteins / Q000235:genetics*; D013997:Time Factors; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins
D000477:Alkylating Agents; D012097:Repressor Proteins; C000624653:TSC2 protein, human; C000624655:Tsc2 protein, rat; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins; D005038:Ethylnitrosourea