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)

Pentosan is a new chemotherapeutic drug which is currently in Phase I clinical trials. In our experimental systems, in vivo, pentosan inhibits the growth of the highly metastatic MAT-LyLu (MLL) Dunning R3327 prostate cancer cell line only at toxic doses and has no apparent effect on growth in vitro. The mechanism of tumor inhibition of this drug is unknown; however, in vitro, pentosan exhibits a potent inhibition of cell motility. Cell motility is essential for tumor cell metastasis and angiogenesis. By blocking cell motility, pentosan has the potential to inhibit both tumor growth and metastasis. We have characterized the mechanism of motility inhibition by pentosan and believe it alters cell-extracellular matrix interactions. The mechanism of motility inhibition by pentosan appears to be independent of cytoskeletal structural alterations, including changes in microfilament and microtubule networks. Pentosan acts through a different mechanism than suramin, a drug which inhibits motility through inhibition of growth factor effects. In vitro, pentosan alters cellular contacts with the extravascular matrix and inhibits cell motility. In vivo, pentosan prolongs survival of rats injected with MLL cells by 25%, but did not appear to decrease the rate of primary tumor growth or the number of metastatic lesions in the treated animals. These data suggest that, in vivo, pentosan acts through an as yet undefined mechanism.
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PMID:Effect of pentosan, a novel cancer chemotherapeutic agent, on prostate cancer cell growth and motility. 137 81

Many grading systems for prostatic carcinoma exist; however, none allows pathologists to predict accurately the prognosis of individual patients. The Dunning R-3327 prostatic adenocarcinoma model consist of sublines of known metastatic potential which were indistinguishable until recently. A visual grading system of cancer cell motility distinguished the metastatic potentials of Dunning sublines maintained in vitro and was validated prospectively. We used this grading system to assess the metastatic potential of cells harvested directly from in vivo Dunning tumors. We graded the motility of cells from three Dunning sublines of low (less than 10%) (G, AT1, AT2) and three sublines of high (greater than 90%) AT3, (MAT-LyLu, PAT2) metastatic potential. Cells obtained from primary tumors were studied by time lapse videomicroscopy after passages 1, 3 and 5 in vivo and in vitro. Membrane ruffling, pseudopodal extension and cellular translation were graded 0-10. Serial analysis of mean and heterogeneity (coefficient of variation) of membrane ruffling, pseudopodal extension and cellular translation demonstrated that subline motility grades were assessed adequately by a sample of 10 cells. Motility did not depend upon whether cells were maintained in vitro or in vivo; however, motility increased with successive passages in four of six sublines. In 60 cells harvested directly from the fifth in vivo passage, three sublines of low metastatic potential were distinguished from three sublines of high metastatic potential (Student's t test, p less than 0.01). Individual cells from the sublines were identified correctly as high or low metastatic in 83, 78 and 70% of cases by membrane ruffling, pseudopodal extension and cellular translation respectively, and logistic regression analysis failed to improve classification accuracy. A visual grading system of cancer cell motility described the metastatic potential of in vivo neoplasms in the Dunning model and may warrant testing in human prostatic cancer.
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PMID:Prediction of metastatic potential by cancer cell motility in the Dunning R-3327 prostatic adenocarcinoma in vivo model. 173 34

Oligosaccharides expressed by the 3327-H and 3327-MAT LyLu sublines of the Dunning rat prostate cancer model have been compared in formalin-fixed and routinely paraffin-embedded tumour tissues. Binding by lectins of defined specificity has been employed to identify expression of seven oligosaccharide structures by primary and metastatic prostatic carcinoma cells. Neuraminidase digestion was employed to reveal determinants masked by sialic acid. The presence of core Man alpha 1----3(Man alpha 1----6)Man beta 1----4GlcNAc beta 1----4 determinants recognised by Con-A (Canavalia ensiformis) confirmed expression of complex-type glycoconjugates by plasma membrane and cytoplasmic components of the 3327-H tumour but only by cytoplasmic determinants within 3327 MAT LyLu variant tumour-cells. The only other oligosaccharide freely expressed by either tumour-subline was (GlcNAc beta 1----4GlcNAc beta 1----4-)n, recognised by WGA (Triticum vulgaris). Prior to neuraminidase digestion, PNA (Arachis hypogaea) (which identifies Type I oligosaccharides: Gal beta 1----3GalNAc-) bound to pseudoluminal membranes of the 3327-H tumour. However, ECG (Erythrina cristagalli) (which identifies type II oligosaccharides: Gal beta 1----4GlcNAc-) did not bind to this tumour. Unmasked Type I (Gal beta 1----3GalNAc-) and Type II (Gal beta 1----4GlcNAc-) oligosaccharides were not identified in the MAT-LyLu variant. After neuraminidase digestion, PNA-binding was identified along pseudoluminal plasma membranes within 3327-H tumours but only within the cytoplasm of 3327-MAT LyLu primary and metastatic tumour cells. Following neuraminidase digestion, ECG-binding was observed along pseudoluminal plasma membranes of 3327-H tumours and heterogeneously within the cytoplasm of primary, but not metastatic 3327-MAT LyLu tumours. Terminal alpha/beta GalNAc- residues recognised by SBA (Glycine max) were not freely expressed by either subline. These structures were readily detected along luminal membranes of 3327-H cells and weakly detected within the cytoplasm of primary but not metastatic MAT 3327-LyLu tumour cells following neuraminidase digestion. Fucosylated Type II structures Fuc alpha 1----2Gal(GalNAc)-), recognised by UEA-1 (Ulex europaeus-1) and GalNAc alpha 1----3GalNAc- structures recognised by DBF (Dolichos biflorus) were not identified as a component of either tumour subline. The different patterns of oligosaccharide expression, identified by lectin-binding, clearly differentiated between the two tumour sublines and distinguished them from normal prostatic epithelium. The Dunning 3327 rat prostatic cancer sublines offer a useful model with which to examine the relationship between cell-surface oligosaccharide structures and phenotypic variants within a defined tumour-cell population.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Differences in expression of oligosaccharide determinants by phenotypically distinct sublines of the Dunning 3327 rat prostate cancer. 238 49

Chemotherapy for prostatic carcinoma is usually reserved for those patients who have failed conventional therapy. These patients generally are in poor health and tolerate chemotherapy poorly. If doses of conventional agents could be decreased without altering cytotoxic activity, then conventional chemotherapy could become an attractive treatment modality. Dimethylsulfoxide and difluoromethylornithine have been shown to induce differentiation in some tumor systems. Growth alteration effects of these two agents were investigated individually and in association with conventional chemotherapeutic agents cyclophosphamide, cisplatin, and fluorouracil in an experimental prostatic cancer model. Copenhagen rats had subcutaneous tumors induced by injections of cells cultured in vitro from a subline of the Dunning rat prostatic tumor, MAT LyLu. Treatment with chemotherapeutic agents individually and associated with differentiation agents was initiated when tumors were palpable. Tumor growth rates and rat body weights were monitored in all groups. The differentiation agents used singly were not able to retard significantly tumor growth rates. In higher doses, each conventional agent used singly significantly retarded tumor growth. Used in combination, the differentiation agents induced cytodestructive properties of lower doses of conventional agents, but some combinations also increased host toxicity. These data suggest that differentiation agents may provide additional antineoplastic benefits when administered in combination with selected chemotherapeutic agents in the management of prostatic cancer.
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PMID:Conventional chemotherapeutic agents combined with DMSO or DFMO in treatment of rat prostate carcinoma. 251 62

Growth alteration effects of an immunomodulator, PSK, were investigated individually and in association with conventional chemotherapeutic agents cyclophosphamide, cisplatin and fluorouracil in an experimental prostatic cancer model. Copenhagen rats had subcutaneous tumors induced by injections of cells cultured in vitro from a highly metastatic hormonally unresponsive subline of the Dunning rat prostatic tumor, MAT-LyLu. Treatment with conventional agents and the immunomodulator agent individually and in combination began three days after tumor cell inoculation. PSK used alone was not able to significantly influence tumor growth. In appropriate doses, each conventional agent significantly retarded tumor growth. Used in combination, PSK and conventional agents retarded tumor growth locally and decreased metastatic spread of the tumor. Animals receiving combination therapy had increased life spans over those animals receiving single standard chemotherapeutic agents. Immunomodulation with PSK may enhance the antineoplastic effects of chemotherapeutic agents and offer a treatment option for hormone resistant prostatic cancer.
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PMID:Combined therapeutic effects of conventional agents and an immunomodulator, PSK, on rat prostatic adenocarcinoma. 258 43

To evaluate if there is any consistent relationship between the expression of intermediate filament proteins (IFP), particularly keratins, and the degree of malignancy of prostatic cancer cells, a series of nine Dunning rat prostatic cancer sublines that span the entire spectrum of progression of prostatic cancer were studied immunocytochemically by the use of a variety of antibodies specific for keratins, vimentin, or desmin. For the keratin studies, monoclonal antibodies with either a general reactivity to several keratins or highly specific for either luminal or basal epithelial cells of the normal rat prostate were used. By use of an antibody specific for luminal cell keratin 18, the luminal tumor cells of the well-differentiated, slow-growing H and HI-S sublines were positively stained. In most of the sublines with a more advanced state of progression (i.e., the moderately differentiated, moderately fast growing HI-M; the poorly differentiated, faster growing HI-F; and the anaplastic, very fast growing AT-1, AT-2, and MAT-Lu tumors), however, no expression of keratin specific for luminal cells was detected. In addition, several of the most advanced sublines (i.e., AT-1, AT-2, and MAT-Lu) were negative using any of the keratin antibodies. In contrast, several of the other sublines with the most advanced degree of progression (i.e., the anaplastic, very fast growing MAT-LyLu tumor derived from the AT-1 subline; and the anaplastic, very fast growing AT-3 tumor, derived from the HI-F subline), however, were positively stained with the keratin antibody specific for the luminal cells. By use of the keratin antibody specific for the basal cells of the normal rat prostate, the basal tumor cells of the well-differentiated slow-growing H and HI-S tumor were positively stained. This positive staining for basal cell keratin was also found in the HI-M and HI-F tumors, while the AT-1, AT-2, MAT-Lu, MAT-LyLu, and AT-3 were negative with this antibody. Thus, a loss in staining for basal cell keratin was consistently associated with the most advanced state of tumor progression. Vimentin-positive staining was demonstrated either alone or with keratin-positive staining in part of the epithelial cancer cells of all the sublines. An increase in the positive staining for vimentin was consistently associated with a more advanced state of tumor progression. Desmin-positive staining was found only in smooth cells present within the various tumor sublines.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Intermediate filament expression and the progression of prostatic cancer as studied in the Dunning R-3327 rat prostatic carcinoma system. 266 36

Employing monoclonal antibodies, the relative frequencies of mononuclear cell types found in spleen cell populations were compared between rats bearing variants of the Dunning prostate adenocarcinoma and a series of non-tumor bearing control animals. The identification and quantitation of such subsets greatly expands our knowledge of immune status and function. The results indicate that the spleen cell populations from animals bearing either the Dunning R3327-H, G or MAT-LyLu sublines have significant decreases in their helper T cell/suppressor T cell ratios when comparisons are made to cells obtained from non-tumor bearing animals. In addition decreases in total T cell content and increases in splenic monocytes were noted. It appears that most of these deviations are the result of general Dunning tumor presence, rather than due to any particular subline characteristic. These changes may be analogous to similar alterations reported in the peripheral blood of humans bearing Stage D prostatic cancer, suggesting that the Dunning tumor may provide an appropriate model for evaluating interactions between the immune response, the tumor and therapy.
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PMID:Leukocytic subset distributions of spleen cells obtained from rats bearing variants of the Dunning prostatic adenocarcinoma. 293 56

The Dunning R3327 adenocarcinoma represents a model for studying prostate cancer in rats; early studies have indicated its utility for studying relationships between tumor growth, immunologic markers, and chemotherapy. Normal animals and those bearing the metastatic Dunning R3327 MAT-LyLu tumor were treated with 10, 30, and 100 mg/kg doses of cyclophosphamide (CTX) and their spleens assayed for leukocytic subset distributions using monoclonal antibodies. Tumor-bearing animals had significant reductions in helper T cell content as well as reduced helper/suppressor T cell ratios, compared to controls. These effects occurred rapidly following implantation and were not reversed by chemotherapy. When administered to both tumor- and non-tumor-bearing animals, CTX also depleted T cell populations. Despite reductions produced in all subsets, two administrations of CTX (30 mg/kg) were capable of retaining (in non-tumor-bearing animals) or restoring (in tumor-bearing) normal helper/suppressor T cell ratios. Such studies aid in identifying therapeutically effective dosages of cytotoxic drugs that minimize their deleterious effects on the immune system.
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PMID:Effect of cyclophosphamide on leukocytic subset distributions in rats carrying the Dunning R3327-MAT-LyLu prostatic adenocarcinoma. 295 10

Data are presented demonstrating that adenylate kinase (AK; EC 2.7.4.3) is an oncodevelopmental enzyme in the prostate of Copenhagen rats. We selected the Dunning tumor (dorsal rat prostate) as a model system because it most nearly approximates the human pathology. Four sublines of the tumor (R3327-H, R3327-AT, MAT Lu, and MAT LyLu) were studied. The tumor sublines were maintained as solid tumors in syngeneic rats and as monolayers in tissue culture. AK activity appeared in conjunction with malignant transformation of the dorsal prostate. We also determined the normal developmental enzyme pattern: AK was present in prostates of newborns, but was undetectable in prostates of adults. However, AK increased after castration. Therefore, we propose AK as a potential oncofetal tumor marker in prostatic cancer.
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PMID:Adenylate kinase: an oncodevelopmental marker in an animal model for human prostatic cancer. 299 6

The MAT-Lu subline of the Dunning R3327 system of rat prostatic adenocarcinomas universally metastasizes to the lungs of untreated recipient hosts. The MAT-Lu cancer was implanted into the hind leg of animals and the primary tumor was allowed to grow to various sizes before the tumor bearing leg was surgically removed. These studies demonstrated that there is a direct relationship between the size of the primary tumor at the time of surgical removal and the number of metastases already established in the lungs. Once the primary MAT-Lu reaches a size of greater than or equal to 0.5 cc, greater than or equal to 50% of all inoculated animals already have established lung metastases and are thus not cured by surgery alone. In an attempt to increase the cure rates, adjuvant chemotherapy (cytoxan given at a dose of 90 mg./kg. body weight) was used in combination with surgery. These studies demonstrated that if chemotherapy was given by itself to animals bearing macroscopically established (greater than or equal to 0.5 cc) MAT-Lu cancers, no animals could be cured. In direct contrast, by combining the same intensity of adjuvant chemotherapy with the removal of the primary MAT-Lu cancer, cures could be produced in high (greater than 90%) frequency, but only if this combinational approach was simultaneously initiated when the primary tumor was less than 2 cc in size. If the primary MAT-Lu cancer was allowed to grow to too large a size before surgery (greater than 2 cc) or if the chemotherapy was delayed following surgery (both processes allowing the metastatic tumor burden to increase before initiating adjuvant chemotherapy), the ability of the adjuvant chemotherapy to cure the host of its metastatic tumor burden is lost. These results demonstrate that the MAT-Lu rat prostatic cancer, like human prostatic cancer, is not effectively treated by chemotherapy alone or by adjuvant chemotherapy combined with surgery if the treatment is given too late in the course of the disease. These studies emphasize the critical requirement of combining surgery and adjuvant chemotherapy as early as possible in the treatment of metastatic prostatic cancer in order to minimize the total metastatic tumor burden and maximize the possibility of cure.
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PMID:Relationship between tumor size and the curability of metastatic prostatic cancer by surgery alone or in combination with adjuvant chemotherapy. 336 56


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