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)

Hyaluronidases degrade hyaluronic acid, which promotes metastasis. HYAL1 type hyaluronidase is an independent prognostic indicator of prostate cancer progression and a biomarker for bladder cancer. However, it is controversial whether hyaluronidase (e.g., HYAL1) functions as a tumor promoter or as a suppressor. We stably transfected prostate cancer cells, DU145 and PC-3 ML, with HYAL1-sense (HYAL1-S), HYAL1-antisense (HYAL1-AS), or vector DNA. HYAL1-AS transfectants were not generated for PC-3 ML because it expresses little HYAL1. HYAL1-S transfectants produced < or = 42 milliunits (moderate overproducers) or > or = 80 milliunits hyaluronidase activity (high producers). HYAL1-AS transfectants produced <10% hyaluronidase activity when compared with vector transfectants (18-24 milliunits). Both blocking HYAL1 expression and high HYAL1 production resulted in a 4- to 5-fold decrease in prostate cancer cell proliferation. HYAL1-AS transfectants had a G2-M block due to decreased cyclin B1, cdc25c, and cdc2/p34 expression and cdc2/p34 kinase activity. High HYAL1 producers had a 3-fold increase in apoptotic activity and mitochondrial depolarization when compared with vector transfectants and expressed activated proapoptotic protein WOX1. Blocking HYAL1 expression inhibited tumor growth by 4- to 7-fold, whereas high HYAL1 producing transfectants either did not form tumors (DU145) or grew 3.5-fold slower (PC-3 ML). Whereas vector and moderate HYAL1 producers generated muscle and blood vessel infiltrating tumors, HYAL1-AS tumors were benign and contained smaller capillaries. Specimens of high HYAL1 producers were 99% free of tumor cells. This study shows that, depending on the concentration, HYAL1 functions as a tumor promoter and as a suppressor and provides a basis for anti-hyaluronidase and high-hyaluronidase treatments for cancer.
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PMID:HYAL1 hyaluronidase in prostate cancer: a tumor promoter and suppressor. 1614 Sep 46

Prostate cancer is the most common invasive malignancy and the second leading cause of cancer-related deaths among U.S. males, with a similar trend in many Western countries. One approach to control this malignancy is its prevention through the use of agents present in diet consumed by humans. Pomegranate from the tree Punica granatum possesses strong antioxidant and antiinflammatory properties. We recently showed that pomegranate fruit extract (PFE) possesses remarkable antitumor-promoting effects in mouse skin. In this study, employing human prostate cancer cells, we evaluated the antiproliferative and proapoptotic properties of PFE. PFE (10-100 microg/ml; 48 h) treatment of highly aggressive human prostate cancer PC3 cells resulted in a dose-dependent inhibition of cell growth/cell viability and induction of apoptosis. Immunoblot analysis revealed that PFE treatment of PC3 cells resulted in (i) induction of Bax and Bak (proapoptotic); (ii) down-regulation of Bcl-X(L) and Bcl-2 (antiapoptotic); (iii) induction of WAF1/p21 and KIP1/p27; (iv) a decrease in cyclins D1, D2, and E; and (v) a decrease in cyclin-dependent kinase (cdk) 2, cdk4, and cdk6 expression. These data establish the involvement of the cyclin kinase inhibitor-cyclin-cdk network during the antiproliferative effects of PFE. Oral administration of PFE (0.1% and 0.2%, wt/vol) to athymic nude mice implanted with androgen-sensitive CWR22Rnu1 cells resulted in a significant inhibition in tumor growth concomitant with a significant decrease in serum prostate-specific antigen levels. We suggest that pomegranate juice may have cancer-chemopreventive as well as cancer-chemotherapeutic effects against prostate cancer in humans.
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PMID:Pomegranate fruit juice for chemoprevention and chemotherapy of prostate cancer. 1619 56

Rapamycin and its derivatives are promising anticancer agents, but the exact mechanisms by which these drugs induce cell cycle arrest and inhibit tumor growth are unknown. A biochemical analysis of human mammary tumor cell lines indicated that rapamycin-induced antiproliferative effects correlated with down-regulation of cellular p21 levels and the levels of p21 in cyclin-dependent kinase (Cdk) 2 and 4 complexes. Cyclin D1 overexpression reversed rapamycin action and this reversal correlated with increased levels of cellular p21, higher levels of p21 associated with Cdk2, and stabilization of cyclin D1/Cdk2/p21/proliferating cell nuclear antigen (PCNA) complexes. Experiments using a novel cyclin D1-Cdk2 fusion protein or a kinase-dead mutant of the fusion protein indicated that reversal of rapamycin action required not only the formation of complexes with p21 and PCNA but also complex-associated kinase activity. Similar results were observed in vivo. The rapamycin derivative RAD001 (everolimus) inhibited the growth of mouse mammary tumors, which correlated with the disruption of cyclin D1/Cdk2 complexes. The potential implications of these results with respect to the use of rapamycin derivatives in breast cancer therapy are discussed.
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PMID:Rapamycin disrupts cyclin/cyclin-dependent kinase/p21/proliferating cell nuclear antigen complexes and cyclin D1 reverses rapamycin action by stabilizing these complexes. 1642 43

Thrombospondin-1 (TSP1) is an endogenous inhibitor of angiogenesis, which limits blood vessel density in normal tissues and curtails tumor growth. Previous studies of the molecular and cellular effects of TSP1 in angiogenesis have been contradictory. Here, we show that retinal endothelial cells (REC) prepared from TSP1-deficient (TSP1-/-) mice are more proliferative and migratory compared to the wild type REC. We observed up-regulation of the cell cycle regulators, including cyclin A, D1, and Cdk2, as well as the enhanced sequential activities of Src, PI3-kinase, Akt/PKB, Rac1/Cdc42 GTPases, and p38 MAP kinase in TSP1-/- REC. The increased levels of fibronectin and active Akt/PKB were also observed in retinal vasculature of TSP1-/- mice in vivo. Inhibition of Src/PI3-kinase/P38 MAP kinase activities in TSP1-/- REC resulted in decreased migration. Furthermore, TSP1-/- REC showed decreased intracellular levels of active Fyn and JNK2 without affecting caspase-3 activity. Thus, our results demonstrate that in the absence of TSP1, the proangiogenic signaling is enhanced, possibly through up-regulation of fibronectin expression. The enhanced signaling further promotes EC proliferation, migration, and survival. These novel observations support the TSP1's role as an endogenous inhibitor of angiogenesis whose endothelium expression promotes a quiescent, differentiated phenotype.
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PMID:Enhanced proangiogenic signaling in thrombospondin-1-deficient retinal endothelial cells. 1662 39

We have synthesized several new phenyl maleimide compounds, which are potent growth inhibitors of several human tumor cell lines. Among these, PM-20 was the most potent with an IC50 of 700 nmol/L for Hep3B human hepatoma cell growth. Two other derivatives, PM-26 and PM-38, did not inhibit Hep3B cell growth even at 100 micromol/L. Interestingly, under identical experimental conditions, PM-20 inhibited DNA synthesis of primary cultures of normal hepatocytes at a 10-fold higher concentration than that needed to inhibit the DNA synthesis of the Hep3B hepatoma cells. PM-20 affected two cellular signaling pathways in Hep3B cells: Cdc25 phosphatase and extracellular signal-regulated kinase (ERK) 1/2. It competitively inhibited the activity of Cdc25 (preferentially Cdc25A) by binding to the active site, likely through the catalytic cysteine, but did not inhibit PTP1B, CD45, or MKP-1 phosphatases. As a result of its action, tyrosine phosphorylation of the cellular Cdc25A substrates Cdk2 and Cdk4 was induced. It also induced strong and persistent phosphorylation of the Cdc25A substrate ERK1/2. Hep3B cell lysates were found to contain ERK2 phosphatase(s) activity, which was inhibited by the actions of PM-20. However, activity of exogenous dual-specificity ERK2 phosphatase MKP1 was not inhibited. Induction of ERK1/2 phosphorylation correlated with the potency of growth inhibition in tumor cell lines and inhibition of ERK1/2 phosphorylation by the mitogen-activated protein kinase (MAPK)/ERK kinase 1/2 inhibitor U0126 or overexpression of the cdc25A gene in Hep3B cells antagonized the growth inhibitory actions of PM-20. Growth of transplantable rat hepatoma cells in vivo was also inhibited by PM-20 action with a concomitant induction of pERK in the tumors. The mechanism(s) of growth inhibition of Hep3B hepatoma cells by the phenyl maleimide PM-20 involves prolonged ERK1/2 phosphorylation, likely resulting from inhibition of the ERK phosphatase Cdc25A. PM-20 thus represents a novel class of tumor growth inhibitor that inhibits mainly Cdc25A, is dependent on ERK activation, and has a considerable margin of selectivity for tumor cells compared with normal cells.
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PMID:PM-20, a novel inhibitor of Cdc25A, induces extracellular signal-regulated kinase 1/2 phosphorylation and inhibits hepatocellular carcinoma growth in vitro and in vivo. 1681 10

Developing novel mechanism-based chemopreventive approaches for lung cancer through the use of dietary substances which humans can accept has become an important goal. In the present study, employing normal human bronchial epithelial cells (NHBE) and human lung carcinoma A549 cells, we first compared the growth inhibitory effects of pomegranate fruit extract (PFE). Treatment of PFE (50-150 microg/ml) for 72 h was found to result in a decrease in the viability of A549 cells but had only minimal effects on NHBE cells as assessed by the MTT and Trypan blue assays. PFE treatment of A549 cells also resulted in dose-dependent arrest of cells in G0-G1 phase of the cell cycle (as assessed by DNA cell cycle analysis). We further found that PFE treatment also resulted in (i) induction of WAF1/p21 and KIP1/p27, (ii) decrease in the protein expressions of cyclins D1, D2 and E, and (iii) decrease in cyclin-dependent kinase (cdk) 2, cdk4 and cdk6 expression. The treatment of cells with PFE inhibited (i) phosphorylation of MAPK proteins, (ii) inhibition of PI3K, (iii) phosphorylation of Akt at Thr308, (iv) NF-kappaB and IKKalpha, (v) degradation and phosphorylation of IkappaBalpha, and (vi) Ki-67 and PCNA. We also found that PFE treatment to A549 cells resulted in inhibition of NF-kappaB DNA-binding activity. Oral administration of PFE (0.1 and 0.2%, wt/vol) to athymic nude mice implanted with A549 cells resulted in a significant inhibition in tumor growth. Our results provide a suggestion that PFE can be a useful chemopreventive/chemotherapeutic agent against human lung cancer.
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PMID:Pomegranate fruit extract inhibits prosurvival pathways in human A549 lung carcinoma cells and tumor growth in athymic nude mice. 1692 Jul 36

For many breast cancer patients, human chorionic gonadotropin beta (hCGbeta), which is a subunit of a hormone produced by the trophoblast and is essential for maintaining pregnancy, is expressed in the breast cancer cells. However, the mechanism as to how the CGbeta in cell affects the cancer development is not very clear. Mouse breast carcinoma 4T1 with stably hCGbeta expression (4T1-hCGbeta) was established and transplanted into the Balb/c mouse abdominal mammary gland. hCGbeta suppressed breast cancer cell viability in vitro, and dramatically inhibited tumor growth and attenuated tumor vessel formation in vivo. An 86-88% reduction in tumor volume in animals injected with breast cancer expressing hCGbeta, as opposed to those injected with breast cancer without hCGbeta expression, was observed. The production of p21 was promoted by hCGbeta, whereas the Cdk2 was decreasing. These indicate that p21 signal pathway is involved in this process. Significant apoptosis was also detected in hCGbeta-expressing breast cancer cells as well as the enhancement of Bax protein expression. Moreover, hCGbeta blocked the blood vessels formation by inhibiting the expression of MMP9 and VEGF. Further hormone secretion analyses show that the anti-tumor activity induced by hCGbeta is not related to the endocrine function.
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PMID:Apoptosis and tumor inhibition induced by human chorionic gonadotropin beta in mouse breast carcinoma. 1692 66

Tumor cells express HYAL1 hyaluronidase, which degrades hyaluronic acid. HYAL1 expression in bladder cancer cells promotes tumor growth, invasion, and angiogenesis. We previously described five alternatively spliced variants of HYAL1 that encode enzymatically inactive proteins. The HYAL1-v1 variant lacks a 30-amino acid sequence that is present in HYAL1. In this study, we examined whether HYAL1-v1 expression affects bladder cancer growth and invasion by stably transfecting HT1376 bladder cancer cells with a HYAL1-v1 cDNA construct. Although HYAL1-v1 transfectants expressed equivalent levels of enzymatically active HYAL1 protein when compared with vector transfectants, their conditioned medium had 4-fold less hyaluronidase activity due to a noncovalent complex formed between HYAL1 and HYAL1-v1 proteins. HYAL1-v1 transfectants grew 3- to 4-fold slower due to cell cycle arrest in the G(2)-M phase and increased apoptosis. In HYAL1-v1 transfectants, cyclin B1, cdc2/p34, and cdc25c levels were > or =2-fold lower than those in vector transfectants. The increased apoptosis in HYAL1-v1 transfectants was due to the extrinsic pathway involving Fas and Fas-associated death domain up-regulation, caspase-8 activation, and BID cleavage, leading to caspase-9 and caspase-3 activation and poly(ADP-ribose) polymerase cleavage. When implanted in athymic mice, HYAL1-v1-expressing tumors grew 3- to 4-fold slower and tumor weights at day 35 were 3- to 6-fold less than the vector tumors (P < 0.001). Whereas vector tumors were infiltrating and had high mitoses and microvessel density, HYAL1-v1 tumors were necrotic, infiltrated with neutrophils, and showed low mitoses and microvessel density. Therefore, HYAL-v1 expression may negatively regulate bladder tumor growth, infiltration, and angiogenesis.
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PMID:HYAL1-v1, an alternatively spliced variant of HYAL1 hyaluronidase: a negative regulator of bladder cancer. 1714 67

Unlike the intact fibronectin (FN) molecule, some proteolytic or recombinant fragments of FN possess inhibitory activities on tumor, providing potential strategies in tumor therapeutics. Using the hydrodynamics-based gene delivery technique, we demonstrated that the treatment by in vivo expression of a recombinant CBD-HepII polypeptide of FN, designated as CH50, strongly inhibited the tumor growth, tumor invasion and angiogenesis. Such inhibitory effects of CH50 on tumor were partly ascribed to its influence on the activities of MMP-9 and alphavbeta3 integrin. The in vivo expressed CH50 decreased both the production and the activity of MMP-9 in tumor tissues. CH50 also down-regulated alphavbeta3 expression in tumor cells and endothelial cells in vitro. The decreased activity of alphavbeta3 integrin was proved by its reduced binding ability to fibrinogen and the down-regulation of cdc2 expression. The gene therapy with CH50 not only prolonged the survival of mice bearing hepatocarcinoma in the liver, but also suppressed the growth and invasive ability of tumor in spleen and its metastasis to liver. Taken together, these findings suggest a prospective utility of CH50 in the gene therapy of liver cancer.
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PMID:Inhibition of hepatocarcinoma and tumor metastasis to liver by gene therapy with recombinant CBD-HepII polypeptide of fibronectin. 1733 Feb 34

Terameprocol (meso-tetra-O-methyl nordihydroguaiaretic acid, formerly known as EM-1421 and M4N) is a semi-synthetic small molecule with antitumor activity occurring via selective targeting of Sp1-regulated proteins, including survivin and cdc2 that control cell cycle and apoptosis. Terameprocol is in clinical development as a site-specific transcription inhibitor in solid refractory tumors. The present studies were designed to investigate the in-vitro and in-vivo anticancer activity of terameprocol in a novel hydroxypropyl beta-cyclodextrin and polyethylene glycol solvent formulation (designated CPE) designed for safe parenteral administration. Terameprocol powder was dissolved in CPE (20% hydroxypropyl beta-cyclodextrin and 50% polyethylene glycol 300 or 30% hydroxypropyl beta-cyclodextrin and 25% polyethylene glycol 300) or dimethyl sulfoxide and used for in-vitro cell proliferation assays, and in human carcinoma xenograft studies using female athymic nude mice injected with SW-780 human bladder cells. Terameprocol (50 and 100 mg/kg), paclitaxel (5 mg/kg), terameprocol and paclitaxel or vehicle was administered intraperitoneally daily for 21 days. Stock solutions of the CPE formulation were stable for up to 12 months. Terameprocol CPE formulation showed concentration-dependent inhibition of HeLa and C33A cell proliferation, and was less toxic than terameprocol dimethyl sulfoxide formulation. The terameprocol CPE formulation showed no overt toxicities in tumor-bearing mice. Terameprocol alone reduced the rate of tumor growth, and a combination of terameprocol/paclitaxel reduced both the rate and extent of tumor growth. These preclinical results confirm the tumoricidal activity of terameprocol formulated in a solvent suitable for parenteral administration and suggest that terameprocol has improved efficacy when coadministered with paclitaxel.
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PMID:The anticancer activity of the transcription inhibitor terameprocol (meso-tetra-O-methyl nordihydroguaiaretic acid) formulated for systemic administration. 1766 99


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