Dunning R-3327 Prostatic Adenocarcinoma Research Articles

The response of Dunning R3327 prostatic adenocarcinoma to IL-2, histamine and radiation.

A syngeneic, androgen-sensitive Dunning R3327 rat prostatic adenocarcinoma was transplanted bilaterally in the flanks of male Copenhagen Fisher rats. Approximately 3 months after implantation, when the tumours had a median volume of 150 mm3, one group of rats was treated with histamine alone (4 mg kg(-1) subcutaneously on week days), another group with human recombinant interleukin 2 (IL-2) alone (425 IU kg(-1) continuous infusion) and a third group with both histamine and IL-2 during 6 weeks. Tumours on one flank were irradiated (6 Gy once daily for 3 days to a total dose of 18 Gy) beginning 1 week after the onset of treatment with histamine and/or IL-2. The contralateral tumour served as the intra-animal control. The tumour volumes were determined weekly. The growth curves showed that all three drug treatments were effective in delaying growth, but when used individually did not cause tumour shrinkage. Radiation was the most effective single agent, but when used alone the shrinkage did not occur until 2 weeks after irradiation. When combined with the drugs, more rapid and extensive growth delay and/or shrinkage was seen. The growth curves showed clear differences between the different treatments. The combination of the three agents was the most effective of all. The most striking difference between radiation alone and radiation plus biotherapy was the time at which a tumour response was detectable. Thus, active biotherapy alone and especially in a combination with histamine and radiotherapy warrants further investigation as a potential therapeutic approach to prostate cancer.

129 - Enhancement of radiation response of Dunning R3327 prostatic adenocarcinoma by IL-2 and histamine

129 - Enhancement of radiation response of Dunning R3327 prostatic adenocarcinoma by IL-2 and histamine

Soy and rye diets inhibit the development of Dunning R3327 prostatic adenocarcinoma in rats.

Two experiments were conducted to investigate the effect of soy and rye on the development of Dunning R3327 prostatic adenocarcinoma in rats.

Point mutations in the Ki-ras2 gene of codon 12 in the Dunning R-3327 Prostatic Adenocarcinoma system.

Detection of point mutations in the Dunning System with the Ki-ras2 gene in the first and second positions of codon 12 exon I, has been performed using allele-specific oligonucleotide (ASO) primers. PCR generated 94bp templates and genomic DNA extracted from the Dunning cell lines AT-1, AT-3, Mat-Lu, and Mat-Lylu were tested. Our investigation revealed that the first and second positions of codon 12 have undergone either transitions or transversions from the wild type sequence (GG). Dorsal prostate (DP) solid tissues used as controls revealed the wild type configuration as well as transversions at both positions, in addition to a transition in the first position for Mat-Lu. The most aberrant of the Dunning lines (AT-3 and Mat-LyLu) collectively displayed sequence changes (transitions and transversions) with no evidence of the wild type configuration. These findings are supportive of biometric studies (area, shape factor, and motility) along with adhesion and invasion assays done in our laboratory in correlating genotypic and phenotypic properties to metastatic potential.

Detection of candidates for cancer cell motility inhibitory protein in the Dunning adenocarcinoma model.

The more differentiated components of a primary tumor may produce substances that reduce the growth rate and metastatic potential of more aggressive components. In the Dunning R-3327 prostatic adenocarcinoma model, cancer cell motility is required for metastatic potential. Medium conditioned by the non-motile, non-metastatic G subline contains proteins of molecular weight 50-100 kDa that inhibited the motility of the highly motile, highly metastatic MAT-LyLu subline. G subline-conditioned medium was separated by DEAE-cellulose chromatography using a linear gradient of 0-0.5 M NaCl in 100 mM Tris at pH 8.3. The motility inhibitory activity of G-conditioned medium was localized to column fractions 51-70 that contained 18% of the applied protein and only 6.5% of the proteins secreted by the G cells. Analysis of pooled fractions 51-60 and 61-70 by two-dimensional gel electrophoresis identified five protein families, with a total of 12 charged proteins of molecular weights approximating 66, 54, 50, 41 and 34 kDa, that were not present or present in reduced quantities in column fractions that did not inhibit motility. Isolation and identification of motility inhibitory protein may prove it the first substance discovered that is produced by a more differentiated component of a neoplasm that directly inhibits a metastasis-associated property.

Castration rapidly results in a major reduction in epithelial cell numbers in the rat prostate, but not in the highly differentiated Dunning R3327 prostatic adenocarcinoma.

Rats with implanted highly differentiated Dunning R3327PAP prostatic tumors were castrated, and at 3, 7, and 14 days thereafter, the effects on tumor volume, epithelial cell numbers, and sizes were quantified using morphometrical methods. The castration response on these parameters was also examined in the normal prostate of the same rats. Castration resulted in a rapid decrease in organ volume, epithelial cell number, and size in the normal prostate, and morphological signs of epithelial cell death (apoptosis) were observed. Tumor growth and mitotic index were reduced, but there were no signs of increased apoptosis, and cell numbers remained fairly constant in the Dunning tumors during the study period. It is concluded that the castration-induced inhibition of tumor growth is caused by factors other than tumor cell death.

Prediction of Metastatic Potential of Aspirated Cells from the Dunning R-3327 Prostatic Adenocarcinoma Model

Pathological grading systems have failed to assess accurately the prognosis of patients with prostatic carcinoma. A visual grading system of cancer cell motility has described successfully the metastatic potential of sublines of the Dunning R-3327 rat prostatic adenocarcinoma model maintained in vitro and in vivo. Clinical application of this technique would be facilitated if it could be performed upon aspirated cells. We compared the motility of cells obtained by biopsy and fine needle aspiration from in vivo Dunning tumors and determined if the motility of aspirated cells could predict metastatic potential. Specimens from the same tumor were obtained by fine needle aspiration and incisional biopsy from three sublines of low (<10%) and three sublines of high (>90%) metastatic potential. Membrane ruffling, pseudopodal extension and cellular translation of 100 cells were graded using time-lapse videomicroscopy. Cells obtained by biopsy and aspiration had similar average (analysis of variance, p >0.7) and variation (coefficient of variation, aspirated = 18.6%, biopsy = 17.7%) of motility. Aspirated cells from three low metastatic sublines (membrane ruffling 5.20 ± SEM 0.41, pseudopodal extension 4.10 ± 0.57 and cellular translation 3.07 ± 0.45) were distinguished from cells of three high metastatic sublines (membrane ruffling 7.10 ± 0.15, pseudopodal extension 6.93 ± 0.22 and cellular translation 5.47 ± 0.25). Cellular translation, the best discriminator, correctly classified the metastatic potential of the subline of origin in 82% of 60 individual cells. A grading system based upon the motility of aspirated cancer cells should be studied in human prostatic carcinoma.

Prediction of Metastatic Potential by Cancer Cell Motility in the Dunning R-3327 Prostatic Adenocarcinoma In Vivo Model

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 (<10%) (G, ATI, AT2) and three sublines of high (>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 <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.

Effects of 6-methylene progesterone on growth, morphology, and blood flow of the Dunning R3327 prostatic adenocarcinoma.

Copenhagen x Fisher F1 rats were implanted with the androgen-dependent Dunning R3327 prostatic adenocarcinoma. When the tumors had median volumes of ca 470 mm3, the rats were castrated and/or treated with 6-methylene-4-pregnene-3,20-dione (6MP) in different doses. Tumor growth inhibition occurred in all castrated and treated groups, with decrease in volume of the epithelial compartment in the intact group. Tumor volumes at the highest dose level of 6MP equalled those observed in the castrate group. Plasma levels of testosterone were within the normal range. The administration of 6MP surprisingly induced an increment of tumor blood flow in the castrate group. Also in castrated and testosterone-supplemented animals, 6MP induced a reduction of prostatic tumor growth. Through the castration-like effect on tumor growth, the use of 6MP may represent an attractive alternative to castration for treatment of androgen-responsive prostate cancer.

Dose/response study of the effects of oestrogens on tumour growth and morphology in the Dunning R3327 prostatic adenocarcinoma

The present study was undertaken to investigate to what extent the oestrogen-induced effects on growth and morphology of the Dunning R3327 rat prostatic adenocarcinoma are dose-dependent. Castrated and testosterone-supplemented rats were used in order to study effects of increasing doses of oestrogens on the tumour. It was found that the lowest dose of oestradiol-17 beta that reduced the overall growth, the volume density of the epithelium and epithelial cell area in Dunning R3327 prostatic tumours is 10 micrograms given as daily injections. Higher oestrogen doses (50 micrograms, 200 micrograms, and 500 micrograms), in addition to reducing the volume of tumour epithelium, also induced an increase of the volume density of tumour stroma. The area of stroma cell nuclei was increased by 50 micrograms and 200 micrograms oestradiol-17 beta. These observation, may indicate that the lowest effective oestrogen dose is different in the epithelium and stroma of Dunning tumours and that large doses of oestrogen stimulate the stromal compartment. This stimulatory effect did not influence the inhibitory effects seen on the overall growth of the tumour and on the tumor epithelium.

Prediction of Metastatic Potential by a New Grading System of Cell Motility: Validation in the Dunning R-3327 Prostatic Adenocarcinoma Model

Many grading systems for prostatic carcinoma exist; however, none allows pathologists to accurately predict the prognosis of individual patients. Examination of dead fixed histological sections of malignancies may not be the best way to predict the biological behavior of living dynamic tumors. We have developed a grading system that reproducibly characterized the motility of living cancer cells. In the Dunning R3327 rat prostatic adenocarcinoma model, three sublines of high metastatic potential (>90%) were distinguished from four sublines of low metastatic potential (<10%). Individual cells from these sublines were correctly identified as high or low metastatic in 96% of cases by grading membrane ruffling, pseudopodal extension, and vectoral translation.

Copenhagen rat prostatic tumor ornithine decarboxylase activity (ODC) and the effect of the ODC inhibitor alpha-difluoromethylornithine.

The R3327MAT-Lu tumor is a rapidly growing anaplastic derivative of the Dunning R3327 prostatic adenocarcinoma. We have found the ornithine decarboxylase (ODC) activity of this tumor to be as sensitive to inhibition by alpha-difluoromethylornithine (DFMO) as normal rat prostate. The same was true for all the other R3327 tumor derivatives we studied. The in vivo inhibition of ODC by DFMO allowed increased uptake of exogenously administered putrescine by the R3327AT tumor. Further, DFMO was inhibitory to the growth of the R3327MAT-Lu both in vitro and in vivo.

13. Comparison between the contents of cytosolic steroid hormone receptors in the Dunning R-3327 prostatic adenocarcinoma of the rat and in human prostatic carcinoma

13. Comparison between the contents of cytosolic steroid hormone receptors in the Dunning R-3327 prostatic adenocarcinoma of the rat and in human prostatic carcinoma