Synthetic inhibitors of CDKs induce different responses in androgen sensitive and androgen insensitive prostatic cancer cell lines.
OBJECTIVE
Because of the high prevalence of prostatic cancer and the limitations of its treatment, enormous effort has been put into the development of new therapeutic modalities. One potential tool is the use of cyclin dependent kinase (CDK) inhibitors, which are based on the trisubstituted derivatives of purine. The aim of this study was to analyse alterations of the regulatory pathways in both androgen sensitive and androgen insensitive prostatic cancer cell lines (LNCaP and DU-145, respectively) after blockage of the cell cycle by the synthetic CDK inhibitors, olomoucine and bohemine.


METHODS
The effects of olomoucine and bohemine were studied on the following parameters: (1) cell proliferation, by measurement of DNA content; (2) viability, by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and/or XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) test; and (3) the expression of p53, pRB, Bcl-2, Bax, p16, p21, p27, cyclins A, B, D1, E, p34(cdc2), and the androgen receptor (AR), by western blot analysis.


RESULTS
Both olomoucine and bohemine were potent inhibitors of growth and viability; however, bohemine was two to three times more effective than olomoucine. The sensitivity of LNCaP cells to both agents was significantly higher. After treatment, both cell lines revealed quite different spectra of protein expression.


CONCLUSIONS
These results indicate the existence of specific cell cycle regulating pathways in both cell lines, which may be associated with both p53 and AR status. CDK inhibitors exhibited valuable secondary effects on the expression of numerous regulators and thus may modulate the responsiveness of tumour cells to treatment, including treatment with hormone antagonists.
Mad'arová
J
J
Laboratory of Molecular Pathology, Faculty of Medicine, Centre of Molecular Biology and Medicine, Palacký University, Hnevotínská 3, CZ-77515 Olomouc, Czech Republic.
Lukesová
M
M
Hlobilková
A
A
Strnad
M
M
Vojtesek
B
B
Lenobel
R
R
Hajdúch
M
M
Murray
P G
PG
Perera
S
S
Kolár
Z
Z
D002455:Cell Division / Q000187:drug effects; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D007701:Kinetin; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism; D009376:Neoplasms, Hormone-Dependent / Q000378:metabolism / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D011687:Purines / Q000494:pharmacology; D011944:Receptors, Androgen / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D004791:Enzyme Inhibitors; D009363:Neoplasm Proteins; D011687:Purines; D011944:Receptors, Androgen; C118034:bohemine; C090046:olomoucine; D018844:Cyclin-Dependent Kinases; D007701:Kinetin