Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To study the relationship between metastatic ability, mutated H-ras expression, and genetic instability, a cloned, nonmetastatic rat prostatic cancer cell line (AT2.1) was transfected with the v-H-ras oncogene. The parental AT2.1 clone, 4 control transfectants (Neo/Only), and 9 v-H-ras transfectants (Neo/Ras) were characterized with regard to their H-ras content by using Southern, Northern, and Western blot analysis and their biological behavior in vivo. Following s.c. inoculation in syngeneic rats, all transfectants produced tumors. All 4 (Neo/Only) transfectants like the parental untransfected cell were non-metastatic. Six of 9 Neo/Ras transfectants were metastatic to the lungs and lymph nodes, while the other 3 Neo/Ras transfectants were not metastatic. There was no simple dose-response relationship between the level of v-H-ras integration, mRNA or p21 protein expression, and the development of metastatic ability by the Neo/Ras transfectants. Cytogenetic analysis demonstrated that the frequency of additional structural and/or additional numerical chromosomal changes among the Neo/Ras transfectants was significantly higher than that in the Neo/Only transfectants (P less than 0.05). Loss of chromosome 10 was observed in all of the Neo/Ras transfectants, whereas that was observed in only one of the 4 Neo/Only transfectants (P less than 0.05). There were no specific chromosomal changes, however, which were statistically correlated with the development of metastases in the Neo/Ras transfectants. These results demonstrate that development of the metastatic ability in AT2.1 cells is not a single-step reaction regulated by the level of H-ras expression alone, but rather a complex process requiring additional events. One of the additional events appears to be an increase in genetic instability and cytogenetic changes following v-H-ras transfection.
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PMID:H-ras expression, genetic instability, and acquisition of metastatic ability by rat prostatic cancer cells following v-H-ras oncogene transfection. 200 21

The network of androgen-dependent growth factors regulating the growth and function of normal or neoplastic prostate epithelium is largely unknown. To facilitate studies directed at investigating this issue, androgen receptor-negative (AR-) PC3 prostate carcinoma cells were stably transfected with the expression plasmid CMV3 containing a constitutively active AR construct that is truncated at its hormone-binding domain (CMV-ARCA). The major characteristic of the resulting cell line (PC3-ARCA) was a growth rate approximately 35% slower than that of a control mock-transfected cell line (PC3-Neo). Of the several growth factors known to be present in the prostate, the current studies focused on the insulin-like growth factor (IGF) axis, specifically the IGF-binding proteins (IGFBPs), several of which are known to be abnormally produced by prostate cancer. Northern analysis showed that IGFBP-1 and -5 are not expressed by PC3-ARCA and -Neo cells. Western ligand and immunoblot analysis of medium conditioned by PC3-Neo and PC3-ARCA cells revealed that equal amounts of IGFBP-2, -4, and -6 were secreted. In contrast, IGFBP-3 was undetectable in the conditioned medium of PC3-ARCA cells, but normally produced by the AR- cell line PC3-Neo. IGFBP-3 disappearance from the conditioned medium of PC3-ARCA cells was transcriptionally regulated, as a marked decrement in IGFBP-3 messenger RNA was detected by S1 protection analysis. We investigated the responses of these cells to exogenously added IGF-I, IGF-II, or IGFBP-3. IGF-I and IGF-II stimulated the proliferation of PC3-ARCA cells, but not of PC3-Neo cells. IGFBP-3 had no effect when given alone. When IGFBP-3 was administered together with IGF-I or IGF-II, it further increased the mitogenic response observed in PC3-ARCA cells, but no effect on PC3-Neo cells was observed. In conclusion, our studies suggest that the presence of an active AR modulates the proliferation of transfected PC3 prostate cancer cells, and that this phenomenon occurs at least in part through the regulation of IGFBP-3 production.
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PMID:Altered growth and insulin-like growth factor-binding protein-3 production in PC3 prostate carcinoma cells stably transfected with a constitutively active androgen receptor complementary deoxyribonucleic acid. 753 76

The early recurrence of prostate cancer originally staged as locally more than T2 and nonmetastatic, cast doubts over the adequacy of the staging of this form of the disease. Monotherapy with curative intent, either by radical prostatectomy or radiotherapy, results in around half of the patients failing within 5 years. While improvements in staging of the disease are essential, the early results of combined modality therapy, particularly the combination of neo-adjuvant hormones and surgery, have been disappointing. Neo-adjuvant maximal androgen blockade followed by radiotherapy does appear to offer survival benefit for patients with locally advanced disease, and other studies combining radiotherapy adjuvant hormonal therapy and surgery with routine postoperative with radiotherapy are eagerly awaited. Combination therapy might not give the hoped-for additive effects of the two therapies, but almost certainly will give an increased incidence of complications.
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PMID:Clinical assessment and management of stage T3 prostate cancer. 926 86

Thalidomide, a glutamic acid derivative, has recently been shown to inhibit in vitro angiogenesis, the process of formation of new blood vessels. This Phase II study examined the pharmacokinetics of thalidomide in patients with clinically progressive hormone-refractory prostate cancer. Patients (aged 55 to 80 years) were randomized to two different arms, low dose versus high dose. Patients in the low-dose group were given 200 mg of thalidomide and patients in the high-dose group received 200 mg of thalidomide, with subsequent dose escalations to 1200 mg. Serial serum or blood samples were obtained for pharmacokinetic assessment after administration of a single oral dose or multiple daily dosing of thalidomide and were assayed by reversed-phase HPLC. Pharmacokinetic parameters for both the single and multiple dosing were calculated with ADAPT II. A one-compartment model best fit the data. After single dosing, the oral clearance and apparent volume of distribution for the low-dose regimen (n = 13) were 7.41 +/- 2.05 L/h and 66.93 +/- 34.27 L, respectively, whereas for the high-dose regimen (n = 11), these values were 7.21 +/- 2.89 L/h and 165.81 +/- 84.18 L, respectively. The elimination half-lives for the low and high dose were 6.52 +/- 3.81 and 18.25 +/- 14.08 h, respectively. After the multiple dosing of thalidomide, the oral clearance and apparent volume of distribution for the low-dose group (n = 10) were 6.35 +/- 1.64 L/h and 64.63 +/- 23.20 L, respectively, whereas for the high-dose group (n = 11), these values were 7.73 +/- 2.27 L/h and 167.85 +/- 82.08 L, respectively. The elimination half-lives for the low and high dose were 7.08 +/- 1.87 and 16.19 +/- 9.57 h, respectively. For both the single and multiple dosing of thalidomide, the apparent volume of distribution and half-life were significantly higher for the high-dose group than those for the low-dose group. The higher apparent volume of distribution may be attributable to several factors, such as change in absorption, protein binding, etc. A dose-proportional increase in thalidomide steady-state concentrations was seen after multiple daily dosing of thalidomide.
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PMID:Pharmacokinetics of thalidomide in an elderly prostate cancer population. 987 12

LNCaP tumors were treated by either administration of paclitaxel, thalidomide or by orchiectomy in order to determine their relationship with markers pertaining to the process of tumor growth, apoptosis or angiogenesis. Forty rats bearing LNCaP tumors were divided into 4 groups of 10 and treated by either paclitaxel (20 mg/kg x 5 days); thalidomide (200 mg/kg x 5 days/week x 5 weeks); or orchiectomy. After 6 weeks serum samples were removed for PSA determination and the animals sacrificed for evaluation of: A) tumor volume; B) tissue bcl-2, cyclin D, PSA and factor VIII immunohistochemically graded (0-5 scale) for marker expression; and C) serum PSA. Comparisons were made to untreated LNCaP tumors. Statistically significant differences were determined using the nonparametric Mann-Whitney test. Paclitaxel produced significant differences in volume (p < 0.001), expression of bcl-2 (p < 0.043), cyclin D (p < 0.023), tissue PSA (p < 0.001) and serum PSA (p < 0.019) levels. Thalidomide altered expression of bcl-2 (p < 0.011) and tissue PSA (p < 0.002). Orchiectomy altered volume (p < 0.002) and bcl-2 expression (p < 0.001). All three therapies have been suggested for prostate cancer and each produced alterations in accepted markers for treatment response (either reduced volume or serum PSA). Paclitaxel significantly influenced the most markers. Of interest was that all treatments, especially thalidomide, a known antiangiogenesis agent, reduced factor VIII, although not significantly. Evidently each treatment evokes different pathways of activity.
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PMID:Paclitaxel is more effective than thalidomide in inhibiting LNCaP tumor growth in a prostate cancer model. 1002 26

We determined whether the IFN-beta gene can be used to suppress angiogenesis, tumor growth, and metastasis of human prostate cancer cells growing in the prostate of nude mice. Highly metastatic PC-3M human prostate cancer cells were engineered to constitutively produce murine IFN-beta subsequent to infection with a retroviral vector containing murine IFN-beta cDNA. Parental (PC-3M-P), control vector-transduced (PC-3M-Neo), and IFN-beta-transduced (PC-3M-IFN-beta) cells were injected into the prostate (orthotopic) or subcutis (ectopic) of nude mice. PC-3M-P and PC-3M-Neo cells produced rapidly growing tumors and regional lymph node metastases, whereas PC-3M-IFN-beta cells did not. PC-3M-IFN-beta cells also suppressed the tumorigenicity of bystander nontransduced prostate cancer cells. PC-3M-IFN-beta cells produced small tumors (3-5 mm in diameter) in nude mice treated with anti-asialo GM1 antibodies and in severe combined immunodeficient/Beige mice. Immunohistochemical staining revealed that PC-3M-IFN-beta tumors were homogeneously infiltrated by macrophages, whereas control tumors contained fewer macrophages at their periphery. Most tumor cells in the control tumors were stained positive by an antibody to proliferative cell nuclear antigen; very few were positively stained by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling. In sharp contrast, PC-3M-IFN-beta tumors contained fewer proliferative cell nuclear antigen-positive cells and many terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling-positive cells. Staining with antibody against CD31 showed that control tumors contained more blood vessels than PC-3M-IFN-beta tumors. PC-3M-IFN-beta cells were more sensitive to lysis mediated by natural killer cells in vitro or to cytostasis mediated by macrophages than control transduced cells. Conditioned medium from PC-3M-IFN-beta cells augmented splenic cell-mediated cytolysis to control tumor cells, which could be neutralized by antibody against IFN-beta. Collectively, the data suggest that the suppression of tumorigenicity and metastasis of PC-3M-IFN-beta cells is due to inhibition of angiogenesis and activation of host effector cells.
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PMID:Suppression of angiogenesis, tumorigenicity, and metastasis by human prostate cancer cells engineered to produce interferon-beta. 1002 78

The breakthrough discovery of the anti-angiogenic effects of thalidomide gave impetus to a series of clinical trials in patients with solid tumors and hematologic malignancies. Thalidomide has been shown to block the activity of angiogenic substances like bFGF, VEGF and interleukin 6. This drug also down-regulates TNF alpha. Thalidomide has shown clinical antitumor activity in single-agent, phase II clinical trials in AIDS-related Kaposi sarcoma, glioma, multiple myeloma refractory to chemotherapy, and hormone-refractory prostate cancer. In contrast, thalidomide was inactive in breast, lung and kidney cancer. The dose-limiting toxicity of thalidomide is sedation. Other adverse effects include skin rash, constipation, dry mouth and liver function abnormalities, along with peripheral neuropathy and the drug's well-known teratogenic potential. The advantages of thalidomide include the convenience of the oral route of administration, the drug's toxicity profile--substantially milder than that of chemotherapy--and its low cost. The potential role of thalidomide in the treatment of human neoplasia will be confirmed by means of randomized clinical trials.
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PMID:[Thalidomide. Clinical trials in cancer]. 1118 34

We prospectively evaluated thalidomide-induced neuropathy using electrodiagnostic studies. Sixty-seven men with metastatic androgen-independent prostate cancer in an open-label trial of oral thalidomide underwent neurologic examinations and nerve conduction studies (NCS) prior to and at 3-month intervals during treatment. NCS included recording of sensory nerve action potentials (SNAPs) from median, radial, ulnar, and sural nerves. SNAP amplitudes for each nerve were expressed as the percentage of its baseline, and the mean of the four was termed the SNAP index. A 40% decline in the SNAP index was considered clinically significant. Thalidomide was discontinued in 55 patients for lack of therapeutic response. Of 67 patients initially enrolled, 24 remained on thalidomide for 3 months, 8 remained at 6 months, and 3 remained at 9 months. Six patients developed neuropathy. Clinical symptoms and a decline in the SNAP index occurred concurrently. Older age and cumulative dose were possible contributing factors. Neuropathy may thus be a common complication of thalidomide in older patients. The SNAP index can be used to monitor peripheral neuropathy, but not for early detection.
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PMID:Thalidomide neuropathy in patients treated for metastatic prostate cancer. 1143 80

Since the NF-kappaB/relA transcription factor is constitutively activated in human prostate cancer cells, we determined whether blocking NF-kappaB/relA activity in human prostate cancer cells affected their angiogenesis, growth, and metastasis in an orthotopic nude mouse model. Highly metastatic PC-3M human prostate cancer cells were transfected with a mutated IkappaBalpha (IkappaBalphaM), which blocks NF-kappaB activity. Parental (PC-3M), control vector-transfected (PC-3M-Neo), and IkappaBalphaM-transfected (PC-3M-IkappaBalphaM) cells were injected into the prostate gland of nude mice. PC-3M and PC-3M-Neo cells produced rapidly growing tumors and regional lymph node metastasis, whereas PC-3M-IkappaBalphaM cells produced slow growing tumors with low metastatic potential. NF-kappaB signaling blockade significantly inhibited in vitro and in vivo expression of three major proangiogenic molecules, VEGF, IL-8, and MMP-9, and hence decreased neoplastic angiogenesis. Inhibition of NF-kappaB activity in PC-3M cells also resulted in the downregulation of MMP-9 mRNA and collagenase activity, resulting in decreased invasion through Matrigel. Collectively, these data suggest that blockade of NF-kappaB activity in PC-3M cells inhibits angiogenesis, invasion, and metastasis.
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PMID:Blockade of NF-kappaB activity in human prostate cancer cells is associated with suppression of angiogenesis, invasion, and metastasis. 1146 85

New therapeutic alternatives are needed to improve outcomes in patients with androgen-independent prostate cancer (AIPC). For several years, researchers at the National Cancer Institute have been interested in elucidating the importance of angiogenesis in the pathogenesis of prostate cancer and in identifying inhibitors of this process. Thalidomide has been shown to inhibit the ability of tumors to recruit new blood vessels. In a recent phase II trial of thalidomide in AIPC, 28% of patients achieved a prostate-specific antigen (PSA) decrease of >40%. The taxane docetaxel also produces PSA and measurable disease responses when used as monotherapy or as a component of combination chemotherapy for AIPC. Thus, based on the single-agent activity of thalidomide and docetaxel, we initiated a randomized phase II study of weekly docetaxel with or without thalidomide, 200 mg at bedtime, in patients with chemotherapy-naive metastatic AIPC. Docetaxel, 30 mg/m(2) intravenously, was administered every 7 days for 3 weeks, followed by a 1-week rest period. Both regimens have been well tolerated among the first 59 treated patients, with a near absence of grade (3/4) myelosuppression. Fatigue, hyperglycemia, and pulmonary toxicity were seen in both groups. Thrombotic events have been seen in the combination arm. Thirty-five percent (6 of 17) of the patients receiving docetaxel alone and 53% (19 of 36) of those receiving docetaxel and thalidomide have had a PSA decrease of at least 50%. Combining a cytotoxic agent with an angiogenesis inhibitor is a promising area of investigation for prostate cancer management.
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PMID:A randomized phase II trial of docetaxel (taxotere) plus thalidomide in androgen-independent prostate cancer. 1168 31


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