Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.22 (cdc2)
 8,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Androgens are known to inhibit the growth of breast cancer cells, but the molecular mechanism of androgen-induced growth inhibition remains unknown. To address this question, we examined functional and quantitative alterations in cell cycle regulators in the E-responsive CAMA-1 breast cancer cell line. We report here that the androgen 5 alpha-dihydrotestosterone inhibits the proliferation of CAMA-1 breast cancer cells. This inhibition of cell proliferation was dose dependent, and maximal inhibition of E2-stimulated proliferation was observed at the concentration of 1 nM 5 alpha-dihydrotestosterone. 5 alpha-Dihydrotestosterone-induced growth arrest was accompanied by an increase in the proportion of cells in the G(1) phase of the cell cycle. Compared with control cells, 5 alpha-dihydrotestosterone-treated cells showed an increase in the relative proportion of hypophosphorylated retinoblastoma protein consistent with G(1) arrest. In CAMA-1 cells, 5 alpha-dihydrotestosterone caused an accumulation of the cyclin-dependent kinase inhibitor p27(Kip1). Cyclin E-cyclin-dependent kinase-2-associated kinase activity was strongly inhibited in 5 alpha-dihydrotestosterone-treated cells, and immunoprecipitation-Western blot analysis showed an increase in the amount of p27(Kip1) associated with cyclin E-cyclin-dependent kinase-2 complexes. These results suggest that inhibition of breast cancer cell growth by androgens may be mediated at least in part by inactivation of the cyclin E-cyclin-dependent kinase-2 complexes by p27(Kip1).
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PMID:Role of the cyclin-dependent kinase inhibitor p27(Kip1) in androgen-induced inhibition of CAMA-1 breast cancer cell proliferation. 1156 93

Apigenin, a common dietary flavonoid abundantly present in fruits and vegetables, may have the potential for prevention and therapy for prostate cancer. Here, we report for the first time that apigenin inhibits the growth of androgen-responsive human prostate carcinoma LNCaP cells and provide molecular understanding of this effect. The cell growth inhibition achieved by apigenin treatment resulted in a significant decrease in AR protein expression along with a decrease in intracellular and secreted forms of PSA. These effects were also observed in DHT-stimulated cells. Further, apigenin treatment of LNCaP cells resulted in G1 arrest in cell cycle progression which was associated with a marked decrease in the protein expression of cyclin D1, D2 and E and their activating partner cdk2, 4 and 6 with concomitant induction of WAF1/p21 and KIP1/p27. The induction of WAF1/p21 appears to be transcriptionally upregulated and is p53 dependent. In addition, apigenin inhibited the hyperphosphorylation of the pRb protein in these cells. Apigenin treatment also resulted in induction of apoptosis as determined by DNA fragmentation, PARP cleavage, fluorescence microscopy and flow cytometry. These effects were found to correlate with a shift in Bax/Bcl-2 ratio more towards apoptosis. Apigenin treatment also resulted in down-modulation of the constitutive expression of NF-kappaB/p65. Taken together, these findings suggest that apigenin has strong potential for development as an agent for prevention against prostate cancer.
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PMID:Involvement of nuclear factor-kappa B, Bax and Bcl-2 in induction of cell cycle arrest and apoptosis by apigenin in human prostate carcinoma cells. 1203 41