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

Gossypol, a polyphenolic aldehyde naturally present in cottonseed, has long been recognized as a male contraceptive and recently as a potential anticancer agent. Our study used a rodent model to evaluate gossypol's potential for the treatment of human prostatic carcinoma. Two-month-old Copenhagen male rats received subcutaneous implants of a subpassage of MAT-LyLu prostatic cancer line, a highly metastatic, androgen-independent Dunning prostate tumor subline that specifically metastasizes to lymph nodes and lungs of recipients. After 2 weeks of gossypol treatment (0 or 12.5 mg/kg B.W./day S.C.) initiated immediately after transplantation, the rats were sacrificed and evaluated for prostate tumor growth and metastasis. Testosterone and gossypol levels in tumor tissue and various reproductive organs and serum potassium level were measured by radioimmunoassay (RIA), high pressure liquid chromatography (HPLC) and atomic emission spectroscopy (AES), respectively. Gossypol-treated rats exhibited weight reductions in developed MAT-LyLu prostate tumor mass and prostate of 24% (p < 0.05) and 31% (p < 0.05), respectively; whereas testicular and epididymal weights were not significantly affected. Few metastases (20%) were observed in either lymph nodes or lungs of gossypol-treated recipients. The control rats, however, had a much higher rate of lung (60%) and lymph node metastasis (40%). Testicular testosterone levels, as measured by RIA, were significantly lower in gossypol-treated rats than in controls (p < 0.05), but serum testosterone levels were not different. Extractable gossypol content in the prostate tumor, as measured by HPLC, reached 19.67 ng/gm and was 1.28 times higher than in liver, 1.98 times higher than in testes, but was 3.3% of that in prostate. Moreover, serum had the highest gossypol content (10.7 micrograms/ml). Serum potassium levels, as measured by AES, were significantly higher in gossypol-treated individuals than controls (p < 0.05). Our results indicate for the first time that gossypol has antiproliferative and antimetastatic effects on MAT-LyLu prostate cancer cells and can be explored as a potential therapeutic agent for androgen-independent human prostatic carcinoma.
 ...
PMID:Antiproliferative and antimetastatic effects of gossypol on Dunning prostate cell-bearing Copenhagen rats. 848 76

Prostatic inhibin peptide (PIP), is a 94 amino acid protein which is secreted by the prostate gland in an androgen-independent manner. Previously, it has been demonstrated that PIP appears to inhibit follicle-stimulating-hormone (FSH) secretion by the pituitary and prostate glands. In vitro, the Dunning R3327 rat prostate cancer cell line MAT-LyLu (MLL) cells and the human prostate cancer cell line PC-3, are stimulated to grow in response to exogenous FSH and these effects are blocked by PIP. In vivo, PIP inhibits the growth of the highly metastatic MLL prostate cancer cell line. A comparison of hormone levels in control and PIP-treated rats demonstrates a significant inhibition of FSH in treated animals. It appears that, in vivo, PIP may inhibit prostate cancer growth by inhibiting FSH. PIP may represent a novel hormonal treatment for prostate cancer.
 ...
PMID:Effect of prostatic inhibin peptide (PIP) on prostate cancer cell growth in vitro and in vivo. 848 55

31P magnetic resonance spectroscopy (MRS) in vivo and in vitro was used to study modulation of host liver (HL) metabolism in rats bearing the MAT-LyLu variant of the Dunning prostate tumour. Animals were inoculated either with 10(6) or 10(7) MAT-LyLu cells, or with saline to serve as controls. Carcass weight in tumour-bearing (TB) animals decreased despite similar food and water intake in both groups. Absence of metastatic tumour cells from HL of all TB animals was confirmed by histological examination. Twenty-one days after inoculation, 31P MRS showed a 2.5-fold increase in [Pi]/[ATP] ratios in HL in vivo (P < 0.001) which was confirmed by 31P MRS of liver extracts in vitro (P < 0.005). Phosphodiester to ATP ratios were significantly increased (P < 0.05) in HL in vivo, but absolute PDE levels were similar in both groups. Phosphomonoester to ATP ratios did not change, although absolute phosphomonoester levels in HL were reduced by -41% (not significant). In HL extracts in vitro, sharp reductions in the levels of glucose-6-phosphate (P < 0.05), fructose-6-phosphate (P = 0.05), phosphocholine (P < 0.001), glycerophosphocholine (P < 0.001), and glycerophosphoethanolamine (P < 0.001) were observed. Electron microscopy revealed increased amounts and altered distribution of rough endoplasmic reticulum in HL. These findings show that experimental prostate cancer significantly affects hepatic phosphorylation status, phospholipid metabolism, and gluconeogenesis in the host animal, and demonstrate the value of combined MRS in vivo and in vitro in monitoring HL metabolism in cancer.
 ...
PMID:Altered phosphorylation status, phospholipid metabolism and gluconeogenesis in the host liver of rats with prostate cancer: a 31P magnetic resonance spectroscopy study. 851 15

CGP 48664A (2-(4-aminoiminomethyl)-2,3-dihydro-1H-inden-1-ylidene dihydrochloride, CAS 149400-88-4) is a new potent inhibitor of S-adenosylmethionine decarboxylase with antitumor properties. In view of the eminent clinical problems in the treatment of non hormone dependent prostatic cancer, the antiproliferative potency of this compound was tested in Dunning MAT-LyLu rat prostatic adenocarcinoma. The compound proved inefficient in preventing the growth of this tumor, even at a near toxic dose. A reason for the lacking effect is presumably the inadequate accumulation of the drug in the tumor cells due to the excessive growth rate of the MAT-LyLu xenografts. Tumor growth seems not to be accompanied by a proportionally rapid vascularization of the tumor mass. CGP 48664A was found to be a potent inhibitor of polyamine oxidase. This property of the drug may have contributed to the activation of the phagocytic capacity of peritoneal macrophages from tumor-bearing rats.
 ...
PMID:Observations with an S-adenosylmethionine decarboxylase inhibitor in rats with prostatic adenocarcinoma. 890 Nov 56

Potential application of lonidamine (LND) to enhance radiation toxicity in prostate cancer was investigated using human prostate cancer cell lines and a rat tumor model (Dunning MAT LyLu). LND alone was cytotoxic with 50% inhibition concentration (IC50) between 0.5 and 0.8 mM. Preincubation with LND increased clonogenic toxicity of radiation. The sensitizer enhancement ratio was 1.8 to 2.2, depending on the cell line tested and it was consistent with inhibition of repair from potentially lethal damage. LND had limited effect in vivo on the Dunning model, consistent with its in vitro effect on the same cell line. LND did not alter the primary growth of the tumor. Fractionated irradiation caused a 40% decrease in tumor growth. LND injection (50 mg/kg) before fractionation did not cause any further decrease in tumor growth. Radiation dose fractionation and the combination treatment significantly reduced tumor metastasis in lungs.
 ...
PMID:Enhancement of radiation response of prostatic carcinoma by lonidamine. 904 39

Northern and Western blotting techniques were used to study expression of the mRNA and corresponding protein product of the S100-related calcium-binding molecule p9Ka in 6 different metastatic cell lines of the Dunning R3327 rat prostate cancer model. In cells with the lowest metastatic capability (G cells), p9Ka mRNA was barely detectable. In 2 weakly metastatic cell lines (AT-1 and AT-2), p9Ka transcript amounts were, respectively, 6.29 +/- 0.74 and 5.55 +/- 1.11 times that detected in the G cells. In 3 highly metastatic cell lines (AT-3, MAT-LyLu and MAT-Lu), the amounts of p9Ka mRNA were, respectively, 12.85 +/- 2.82, 13.06 +/- 1.69 and 11.62 +/- 1.81 times that expressed in the G cells. Western blot analyses detected no p9Ka protein in the G cells. The amounts of p9Ka protein expressed by tumour cells of intermediate metastatic capability (AT-1 and AT-2) were 3.4 +/- 1.3 microg and 3.3 +/- 1.4 microg, respectively, per 1 x 10(6) cells. The amounts of p9Ka protein expressed by the tumour cells of highest metastatic capability (AT-3, MAT-LyLu and MAT-Lu) were 8.3 +/- 1.1 microg, 8.7 +/- 1.6 microg and 9.6 +/- 1.7 microg, respectively, per 1 x 10(6) cells. Our data reveal a direct association between the elevated expression of mRNA and the p9Ka protein amounts and the increased metastatic capability of individual prostatic cancer cell lines. We suggest that calcium-binding protein p9Ka may play an important role in the metastatic behaviour of rat prostate cancer.
 ...
PMID:Elevated expression of calcium-binding protein p9Ka is associated with increasing malignant characteristics of rat prostate carcinoma cells. 918 Jan 53

Binding of the serine protease urokinase (u-PA) to its receptor on tumor cell surfaces facilitates proteolysis and tumor invasion. We undertook this study to determine whether the role of u-PA in prostate cancer induced angiogenesis and secondary tumor growth by developing a homologous, immunocompetent in vivo model in which the tumors cells secrete an inhibitor of the murine u-PA receptor. A mutant recombinant murine u-PA that retains receptor binding but not proteolytic activity was made by PCR mutagenesis. Mutant u-PA and a reporter gene pRK luciferase were transfected and stably expressed in the highly metastatic rat Dunning MAT-LyLu prostate cancer cell line. Several clones expressing mutant u-PA and luciferase were identified by Western blotting, plasminogen zymography, and reverse transcription-PCR. One of these clones, 5C4, was injected s.c. into Copenhagen rats. Compared to animals injected with clones expressing pRK luciferase alone, tumors in animals injected with 5C4 cells were significantly smaller. Moreover, there were fewer lung micrometastases in the 5C4 animals. Primary tumor angiogenesis was measured by microvessel quantification of tissue stained with antibodies against von Willebrand factor. Mean microvessel density in 5C4 tumors was 4.3-fold lower than that in animals with tumors derived from the control tumor cell line (P < 0.0001). Significant inhibition of tumor growth was also observed for two additional MAT-LyLu cell lines expressing mutant u-PA. These findings suggest that cell surface u-PA contributes to prostate cancer growth by enhancing angiogenesis.
 ...
PMID:Inhibition of prostate cancer neovascularization and growth by urokinase-plasminogen activator receptor blockade. 927 33

Prostate cancer remains the most commonly diagnosed cancer in American males and is the second leading cause of cancer death in this group. Hydrazine sulfate, an inhibitor of gluconeogenesis, has been proposed as a means to improve nutritional status and improve survival in patients with solid tumors. We investigated the effects of hydrazine sulfate on both in vitro and in vivo models of prostate cancer. We examined the cytotoxicity of hydrazine sulfate in both human (LNCaP and PC-3) and animal (MAT-LyLu) prostate cancer cell lines. No growth inhibition was observed. In vivo, hydrazine sulfate did not suppress the growth of implanted Dunning rat prostate MAT-LyLu cells. Hydrazine sulfate does not have activity in these models of prostate cancer and may not be an appropriate therapy for patients with prostate cancer.
 ...
PMID:The effect of hydrazine sulfate on prostate cancer growth. 962 46

Phenylbutyrate (PB), a novel lead compound for prostate cancer therapy, has molecular activities distinct from its metabolite, phenylacetate (PA). Both PB and PA promote differentiation in human prostate cancer cell lines, yet little data exist comparing the cytotoxic effects of each drug. We found that PB is more potent than PA in vitro; PB is 1.5-2.5 times more active at inhibiting growth and inducing programmed cell death than PA at clinically achievable doses against each human prostate cancer line studied. PB is equipotent to sodium butyrate, which induces apoptosis and differentiation through multiple mechanisms. Exposure of prostate cancer cell lines to PB reduces their DNA synthesis, leads to fragmentation of genomic DNA, and causes 50-60% of cells to undergo apoptosis. These PB-induced effects are 2-10 times greater than those of the control or PA. The stereotypical changes of apoptosis can be seen with sodium butyrate at similar concentrations, but not with PA. Prostate cancer cell lines overexpressing P-glycoprotein or possessing heterogeneous molecular alterations, including p53 mutations, are also sensitive to the effects of PB. In vivo, Copenhagen rats treated with oral PB had delayed growth of the androgen refractory Dunning R-3327 MAT-LyLu prostate cancer subline by 30-45% in a dose-dependent manner. These results demonstrate that PB induces cytotoxicity via apoptosis in human prostate cancer, in addition to its differentiating properties.
 ...
PMID:Phenylbutyrate induces apoptosis in human prostate cancer and is more potent than phenylacetate. 981 81

Voltage-gated Na+ channels are expressed by highly metastatic MAT-LyLu cells, but not by poorly metastatic AT-2 cells, derived from the rodent Dunning model of prostatic cancer. We have investigated the possible involvement of these channels in the morphological development of the cells. Incubation of both the MAT-LyLu and the AT-2 cell line for 24 h with the Na+ channel blocker tetrodotoxin (TTX) at 6 microM altered the morphology only of the MAT-LyLu cell line. TTX produced significant decreases in: (a) cell process length and (b) field diameter, and increases in (c) cell body diameter and (d) process thickness. Importantly, 6 microM TTX had no significant effects on proliferation rates or cellular toxicity. The results suggest that Na+ channel activity plays a significant role in determining the morphological development of MAT-LyLu cells in such a way as to enhance their metastatic potential.
 ...
PMID:Tetrodotoxin suppresses morphological enhancement of the metastatic MAT-LyLu rat prostate cancer cell line. 1002 70


<< Previous 1 2 3 4 5 6 7 8 Next >>