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Biomedical subjects

Raymond C Bergan

Publications and source records attributed to Raymond C Bergan.

10 recordsLinked to original sources
PubMed2006

Genistein inhibits matrix metalloproteinase type 2 activation and prostate cancer cell invasion by blocking the transforming growth factor beta-mediated activation of mitogen-activated protein kinase-activated protein kinase 2-27-kDa heat shock protein pathway.

Genistein is a candidate cancer chemopreventive drug being tested in clinical trials. We have shown that genistein blocks prostate cancer (PCa) cell invasion, that p38 mitogen-activated protein (MAP) kinase regulates activation of matrix metalloproteinase type 2 (MMP-2) and cell invasion, and that genistein prevents transforming growth factor beta (TGFbeta) from activating p38 MAP kinase. More recently, we identified MAP kinase-activated protein kinase 2 (MAPKAPK2) and the 27-kDa heat shock protein (HSP27) as downstream regulators of p38 MAP kinase. However, MAPKAPK2 and HSP27 can be regulated by factors other than p38 MAP kinase, and HSP27 is up-regulated during PCa progression. The current study was undertaken to examine the role of MAPKAPK2 and HSP27 in modulating genistein-mediated regulation of PCa cell invasion. Genistein inhibited TGFbeta-mediated phosphorylation of MAPKAPK2 and HSP27. Inhibitory effects by genistein upon cell signaling, inhibition of MMP-2, and inhibition of invasion were retained when both PC3 and PC3-M cells were transfected with either wild-type MAPKAPK2 or HSP27. However, transfection with dominant-negative MAPKAPK2 or nonphosphorylatable mutant HSP27 led to decreases in cell invasion and to abrogation of responsiveness to either TGFbeta-mediated increases or genistein-mediated decreases in MMP-2 and cell invasion. It is noteworthy that, after transfection with constitutive active MAPKAPK2 or with pseudophosphorylated HSP27, levels of MMP-2 activation and cell invasion were high and overcame any inhibitory effect of genistein. These findings demonstrate that genistein-mediated inhibition of cell invasion rests upon blocking activation of the MAPKAPK2-HSP27 pathway, and that its activation during cancer progression has the potential to mitigate therapeutic efficacy.

Antineoplastic Agents↗
PubMed2006

Phase II study of mitoxantrone and ketoconazole for hormone-refractory prostate cancer.

BACKGROUND: Doxorubicin plus ketoconazole has exhibited significant activity in patients with advanced prostate cancer. However, overall and cardiac-specific toxicity was reported to be high. Mitoxantrone has activity similar to that of doxorubicin, is less cardiotoxic, and is widely used to treat prostate cancer. The current study sought to evaluate the toxicity and activity of mitoxantrone plus ketoconazole in a cohort of patients with hormone-refractory prostate cancer. METHODS: Progression after medical or surgical castration and, for those patients receiving antiandrogens, progression after withdrawal was required, as was objective evidence of metastasis, castrate levels of testosterone, an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2, and intact cardiac function. After enrollment onto a multicenter local consortium study, subjects were treated with mitoxantrone at a dose of 12 mg/m2 intravenously every 3 weeks plus continuous oral ketoconazole at a dose of 400 mg 3 times daily and ascorbic acid at a dose of 250 mg. Replacement doses of hydrocortisone were given. RESULTS: For 40 enrolled subjects, the median prostate-specific antigen and ECOG performance status were 68 and 1, respectively, 53% had Gleason scores of 8 to 10, and all had metastasis. Predominant Grade 3/4 toxicities were: neutropenia in 13%, neutropenic fever in 10%, and anemia in 13%. Of 37 evaluable patients, 8% achieved a complete remission (CR) and 62% achieved a partial remission (PR), for a CR plus PR rate of 70%. For soft tissue and bone disease, overall response rates were 13% and 8%, respectively. The median progression-free survival and overall survival were 10 months and 18 months, respectively. CONCLUSIONS: Mitoxantrone plus ketoconazole is well tolerated, is active in hormone-refractory prostate cancer, and should be studied further.

Aged↗
PubMed2005

Genistein inhibits p38 map kinase activation, matrix metalloproteinase type 2, and cell invasion in human prostate epithelial cells.

Epidemiologic studies associate consumption of genistein, in the form of dietary soy, with lower rates of metastatic prostate cancer. We have previously shown that genistein inhibits prostate cancer cell detachment in vitro, that it is well tolerated in an older cohort of men with prostate cancer, and that it alters cell signaling in that same cohort. We have also shown that p38 mitogen-activated protein kinase (MAPK) is necessary for transforming growth factor beta (TGF-beta)-mediated increases in prostate cancer adhesion. Although cell invasion is closely linked to metastatic behavior, little is known about how this process is regulated in prostate cancer or what effect, if any, genistein has on associated processes. We now show that genistein inhibits matrix metalloproteinase type 2 (MMP-2) activity in six of seven prostate cell lines tested, blocks MMP-2 induction by TGF-beta, and inhibits cell invasion. Efficacy was seen at low nanomolar concentrations, corresponding to blood concentrations of free genistein attained after dietary consumption. Inhibition of p38 MAPK by either SB203580 or dominant-negative construct blocked induction of MMP-2 and cell invasion by TGF-beta. Genistein exerted similar effects and was found to block activation of p38 MAPK by TGF-beta. This study shows that p38 MAPK is necessary for TGF-beta-mediated induction of MMP-2 and cell invasion in prostate cancer and that genistein blocks activation of p38 MAPK, thereby inhibiting processes closely linked to metastasis, and does so at concentrations associated with dietary consumption. Any potential causal link to epidemiologic findings will require further investigation.

Cell Line↗
PubMed2005

Renal medullary carcinoma and ABL gene amplification.

PURPOSE: We characterized the clinical course of renal medullary carcinoma (RMC) and performed an expanded analysis of BCR-ABL. MATERIALS AND METHODS: The literature was searched for all reports of RMC. New cases at Northwestern University are described and relevant clinical information was abstracted. BCR and ABL genes, and ABL protein were evaluated by fluorescence in situ hybridization and immunohistochemical analysis, respectively. RESULTS: A total of 95 cases were identified. Mean age at diagnosis was 19 years, the male-to-female ratio was 1.9:1.0, 90% of all patients were black, 98% had an abnormality in a least 1 hemoglobin gene (ie sickle cell trait, SC disease or sickle cell disease) and mean survival was 19 weeks. Two patients (3%) without metastasis were long-term survivors. The response to chemotherapy was poor. One patient treated with thalidomide survived for 52 weeks. The ABL gene was amplified a mean +/- SEM of 1.9 +/- 0.1-fold in all 3 cases evaluated, while ABL protein was increased in 2 of 3 evaluated. No evidence of BCR-ABL translocation was detected. CONCLUSIONS: RMC is typically seen in young individuals with the sickle cell trait. It is diagnosed when metastatic, is not responsive to systemic therapy and rapidly causes death. Because cure appears possible with early diagnosis, increased awareness of the disease could make an impact. The use of thalidomide or newer anti-angiogenesis agents should be considered for advanced disease. The role of ABL amplification with respect to etiology and as a therapeutic target should be investigated further.

Adolescent↗
PubMed2005

Safety and efficacy of weekly oral oltipraz in chronic smokers.

Cigarette smoking is thought to contribute to carcinogenesis by formation of DNA adducts of tobacco smoke constituents leading to genotoxic damage. The dithiolethione, oltipraz, is a putative cancer chemopreventive agent that induces phase II detoxifying enzymes in preclinical models and reduces aflatoxin adducts in humans living in areas with high dietary levels. To determine if oltipraz could reduce adduct levels of tobacco smoke constituents in the lungs and other target organs, chronic smokers were enrolled to one of three arms: 400 or 200 mg/wk oral oltipraz or placebo. Endobronchial tissue and bronchoalveolar lavage were done before and after 12 weeks of drug treatment; peripheral blood, urine, and oral saline rinse were also collected. Toxicity was assessed every 4 weeks. Fifty-nine of the 77 enrolled subjects completed the study. Of those receiving oltipraz, 15% experienced grade 2/3 toxicity, which was predominantly gastrointestinal. All subject withdrawals occurred in the oltipraz groups. There was no significant difference between pre- and post-polycyclic aromatic hydrocarbon-DNA adduct levels in lung epithelial cells measured by immunoperoxidase staining between treatment and placebo groups. Likewise, no significant differences were found in polycyclic aromatic hydrocarbon or benzo(a)pyrene-7,8-diol-9,10-epoxide adducts measured in blood, oral lining cells, or bladder lining cells. There was also no increase in mRNA or enzymatic activity of phase II enzymes and no change in glutathione levels. Thus, despite moderate drug-related toxicity, there was no significant effect on pharmacodynamic or surrogate risk biomarkers. Other agents with lower toxicity and greater activity to induce phase II enzymes are needed to definitively test the detoxification-induction paradigm in smokers.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed2003

p38 MAP kinase modulates Smad-dependent changes in human prostate cell adhesion.

Transforming growth factor beta (TGFbeta) regulates cell adhesion, proliferation, and differentiation in a variety of cells. Smad proteins are receptor-activated transcription factors that translocate to the nucleus in response to TGFbeta. We demonstrate here that TGFbeta increases cell adhesion in metastatic PC3-M prostate cancer cells. TGFbeta treatment of PC3-M cells leads to nuclear translocation of R-Smad proteins. We show that Smad proteins are necessary, but not sufficient, for TGFbeta-mediated cell adhesion. After showing that TGFbeta upregulated p38 MAP kinase activity in PC3-M cells, we show that inhibition of p38 MAP kinase partially blocked TGFbeta-mediated increase in cell adhesion, as well as nuclear translocation of Smad3. Finally, we show that Smad3 is phosphorylated by p38 MAP kinase in vitro. These findings implicate crosstalk between the MAP kinase and Smad signaling pathways in TGFbeta's regulation of cell adhesion in human prostate cells. This represents a mechanism by which the pleiotropic effects of TGFbeta may be channeled to modulate cell adhesion.

Adenocarcinoma↗
PubMed2003

Phase I pharmacokinetic and pharmacodynamic analysis of unconjugated soy isoflavones administered to individuals with cancer.

Preclinical studies suggest that the isoflavone genistein may have prostate cancer chemopreventive activity. Genistein has been shown to alter cellular levels of protein-tyrosine phosphorylation and is present at high levels in soy. This study was designed to measure the pharmacokinetic parameters of two different preparations of unconjugated soy isoflavones, PTI G-2535 and PTI G-4660 (which contain 43% and 90% genistein, respectively), in human subjects with cancer, to evaluate toxicity and obtain pilot data on in vivo effects on protein-tyrosine phosphorylation. Cohorts of four patients were given single doses of each preparation; each dose was separated by 1 week. Sequential cohorts received genistein at 2, 4, or 8 mg/kg orally. Pharmacokinetic sampling was performed after each dose, and tyrosine phosphorylation was measured in proteins extracted from peripheral blood mononuclear cells. One of 13 patients treated developed a treatment-related rash. No other toxicities were observed. Maximal plasma concentrations (C(max)) ranged between 4.3 and 16.3 micro M for total genistein and 0.066 and 0.17 micro M for free genistein. For PTI G-2535 and PTI G-4660, half-life was 15.03 and 22.41 h, respectively, and volume of distribution was 189.9 and 653.8 liters, respectively, and there was a trend toward higher area under the concentration curve for PTI G-2535 (P = 0.07 at the 8 mg/kg dose). Treatment-related increases in tyrosine phosphorylation were observed in peripheral blood mononuclear cells. Oral administration of soy isoflavones gives plasma concentrations of genistein that have been associated with antimetastatic activity in vitro.

Administration, Oral↗
PubMed2002

Over expression of endoglin in human prostate cancer suppresses cell detachment, migration and invasion.

The regulation of cell adhesion and motility in human prostate is not well understood. We have previously shown that the endoglin gene is differently expressed during changes in prostate cell adhesion. Endoglin is a transmembrane transforming growth factor beta binding protein typically expressed by endothelial cells. In this report we demonstrate that endoglin over expression increases prostate cell attachment, while decreasing migration and invasion. Engineered decreases in endoglin expression have opposite effects. While endoglin exerted only relatively small effects upon cell adhesion, large effects upon cell migration and invasion were observed. Endoglin was shown to localize to focal adhesion plaques, consistent with its role in regulating cell adhesion and motility. Loss of endoglin expression in cancer, as compared to normal prostate, was seen in human prostate cell lines. Suppression of endoglin expression in a panel of normal human prostate cell lines led to cell detachment. Endoglin is identified as a regulator of cell adhesion, motility and invasion in human prostate. Loss of endoglin expression appears to be associated with prostate cancer progression, at least in vitro.

Antigens, CD↗