Expression of ras proto-oncogenes in the Dunning R3327 rat prostatic adenocarcinoma system.
Steady-state levels of c-Ha-ras mRNA were measured in eight sublines of the Dunning R3327 rat prostatic adenocarcinoma. As a control, normal dorsal prostate tissue was studied. Increased expression of c-Ha-ras is associated with tumor progression in one lineage of the Dunning R3327 system (H to AT1 to MAT-Lu and MAT-Ly-Lu). Here ras mRNA increases as the tumor advances from androgen dependence and a high degree of differentiation to an anaplastic aneuploid phenotype with high metastatic potential. However, in the other Dunning lineage (H to HI to HI-F to AT3), expression of c-Ha-ras is variable and does not correlate with tumor progression. Immunocytochemistry showed that levels of the c-Ha-ras p21 protein paralleled steady-state mRNA levels in variants. Transfection assays, using NIH/3T3 cells, suggested that the ras loci were not activated in the R3327 tumors. Levels of c-Ki-ras mRNA were also measured in the Dunning tumors; these did not correlate with tumor progression in either lineage. Expression of N-ras mRNA was not detected in the Dunning tumors.
Cooke
D B
DB
Lineberger Cancer Center, University of North Carolina, Chapel Hill 27599.
Quarmby
V E
VE
Petrusz
P
P
Mickey
D D
DD
Der
C J
CJ
Isaacs
J T
JT
French
F S
FS
D000230:Adenocarcinoma / Q000235:genetics*; D000818:Animals; D011905:Genes, ras; D008297:Male; D011471:Prostatic Neoplasms / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000032:analysis; D016283:Proto-Oncogene Proteins p21(ras); D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D014407:Tumor Cells, Cultured
D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D016283:Proto-Oncogene Proteins p21(ras)