Expression of cathepsin L and its endogenous inhibitors in immortal and transformed fibroblasts.
METHODS
The activities of cathepsin L and its endogenous inhibitors were analyzed in rat embryo fibroblasts, immortalized and transformed by different genes.


RESULTS
Regardless of the transfecting agent used (DNA of adenovirus SA7 or polyomavirus LT gene), the immortal cells showed an increase in the cathepsin L activity (in both lysates and conditioned media) compared to primary fibroblasts. Transformed cells exhibited either an increase (with c-Ha-ras gene) or decrease (with E7 HPV gene) in cathepsin L activity in lysates as opposed to immortal cells.


CONCLUSIONS
The data are suggestive of alterations in the trafficking of cathepsin L upon fibroblast transfection with polyomavirus LT gene and E7 HPV gene. An endogenous inhibitor(s) of cysteine proteinase was found in conditioned media, but not in lysates, of all cell cultures studied and its activity in normal fibroblasts was higher than in media of immortal and transformed cells.
Dilakyan
E A
EA
Institute of Biomedical Chemistry, Russian Academy of Medical Sciences (RAMS), Pogodinskaya St. 10, 119992, Moscow, Russia.
Zhurbitskaya
V A
VA
Vinokurova
S V
SV
Gureeva
T A
TA
Lubkova
O N
ON
Topol
L Z
LZ
Kisseljov
F L
FL
Solovyeva
N I
NI
D017500:Adenovirus E1A Proteins / Q000235:genetics; D000261:Adenoviruses, Simian / Q000235:genetics; D000818:Animals; D056668:Cathepsin L; D002403:Cathepsins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics; D002461:Cell Line, Transformed / Q000166:cytology / Q000378:metabolism; D003546:Cysteine Endopeptidases; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism; D004247:DNA / Q000235:genetics*; D004622:Embryo, Mammalian / Q000166:cytology; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D011905:Genes, ras / Q000235:genetics; D051381:Rats; D014162:Transfection
D017500:Adenovirus E1A Proteins; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D004247:DNA; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D056668:Cathepsin L; C534280:Ctsl protein, rat