Heparin-binding growth factor isolated from human prostatic extracts

Immunohistochemical Expression of Angiogenic Factors by Neoplastic Epithelial Cells Is Associated With Canine Prostatic Carcinogenesis

The dog is the only species, other than humans, in which spontaneous prostatic cancer occurs; therefore, dogs are a valuable model for the study of factors that regulate tumor progression. Angiogenesis is important in the development and spread of a variety of cancers, including prostate cancer. To better define the role of cancer epithelial cells in prostate cancer neovascularization, immunohistochemical staining for angiogenic factors (vascular endothelial growth factor [VEGF], platelet endothelial cell adhesion molecule–1 [PECAM-1], Tie-2, and fibroblast growth factor–2 [FGF-2]) was performed on formalin-fixed, paraffin-embedded tissues from 10 normal prostates, 15 hyperplastic prostates, and 11 prostatic carcinomas from dogs. Normal and hyperplastic epithelial cells were negative for PECAM-1, VEGF, and Tie-2, while the same markers were expressed with a variable intensity of cytoplasmic staining by neoplastic cells. Mild to moderate FGF-2 staining was detected in all normal prostates with less than 10% of positive cells, mainly distributed in the basal layer. The percentage of FGF-2–positive hyperplastic cells was variable, with both basal and secretory cells exhibiting a perinuclear to diffuse cytoplasmic staining. The mean number of positive cells and the intensity of staining were higher in prostatic carcinomas than normal and hyperplastic prostates. Moreover, microvessel density analyzed on PECAM-1–stained slides was increased in prostate cancer compared with normal and hyperplastic prostates. Therefore, prostatic neoplastic cells are capable of simultaneous expression of various angiogenic factors and may increase tumor proliferation and angiogenesis in a paracrine and autocrine fashion.

Immune function, mitogenicity, and angiogenic growth factor concentrations in lean and obese rodent sera: implications in obesity-related prostate tumor biology

Some studies suggest that several tumors have a greater incidence in those patients with a high fat diet, such as colon, breast, and prostate. However, we wanted to determine the effects of obesity alone, independent of diet, on the progression of prostate tumor growth. Using a genetic model of obese and lean Zucker rats, we wanted to demonstrate any sera differences in the concentration of basic fibroblast growth factor (FGF-2) and vascular endothelial cell growth factor (VEGF), two important factors involved in the growth and progression of prostate cancer. We also wanted to investigate if there were any differences in immune function between the two sera, which could also account for uninhibited tumor growth, as well as differences in mitogenic stimulation. Female Zucker rat obese and lean sera were analyzed using ELISA assays for FGF-2, VEGF, and macrophage inflammatory protein-1 alpha (MIP-1a), as a measure of macrophage function. In addition, the sera of lean and obese sera were plated on wells growing LNCaP prostate cancer cells to determine differences in mitogenicity. We found a greater concentration of FGF-2 in the sera from obese Zucker rats compared to lean Zucker rats: 6.32+/-0.56 vs 3.48+/-0.34 pg/ml, respectively, P<0.05). We also demonstrated a greater concentration of VEGF in obese rat sera compared to lean sera: 54.4+/-4.1 vs 38.0+/-2.9 pg/mL, respectively, P<0.05). We detected a trend in mitogenic stimulation among LNCaP cells along the higher concentrations of the dose-response curve (0.72+/-0.06 vs 0.51+/-0.5). However, this was not statistically significant. In addition, we did not find a significant difference in MIP-1a macrophage activity levels between sera. To conclude, we speculate that the greater concentrations of VEGF and FGF-2 in the sera of obese rodents vs lean rodents may account for some of the differences seen in obesity-related tumor growth seen in the human condition. However, the lack of any sera differences of immune function, as measured by macrophage activity, as well as no significant differences on mitogenic proliferation on LNCaP prostate cancer cells, suggests that other mechanisms may exist to explain differences seen in obesity-related prostate tumor biology.

The impact of obesity in urology

The incidence and progression of urologic diseases, as well as several urologic cancers.depend on many interrelated factors, such as obesity, diet, genetics, environment, age, and the immune system. Obesity is a risk factor for stress urinary incontinence, ED, infertility, and renal calculi. Numerous publications have demonstrated that a high dietary intake of fat increases prostate cancer risk, although the mechanisms are not clear. Although some reports may demonstrate an association between obesity and prostate cancer, it may be hard to establish because, in general, men with obesity have a high-fat diet. Obesity, recurrent urinary tract infections, increased intake of protein and fried foods, and female sex seem to increase the risk of renal cancer. Environmental toxins seem to be the major factors affecting the incidence of bladder cancers. Thus, dietary modification and other public health measures directed at reducing weight may reduce the incidence of urologic illnesses. More studies are necessary to determine the therapeutic effects of weight loss and dietary modification on the incidence and progression of urologic tumors.

Expression of bone morphogenetic protein-7 (BMP-7) in human prostate

BACKGROUND

It is known that BMP is a factor that strongly induces bone formation in muscle tissue. However, the expression of BMP-7 is not detected in normal bone tissues. Recently, we reported that the level of BMP-7 expression was significantly higher in metastatic bone lesions than in normal bone and that the high expression of BMP-7 in metastatic bone lesions was related to osteoblastic metastasis. The aim of this study was to investigate the level of BMP-7 gene expression in normal prostate glandular tissues, newly diagnosed prostate cancer tissues, and local recurrent prostate cancer tissues.

METHODS

Total RNA was extracted from 23 samples of normal prostate glandular tissues, 28 samples of newly diagnosed prostate cancer tissues, and 23 samples of local recurrent prostate cancer tissues. We also examined the expression of BMP-7 in human prostatic epithelial cells (HPECs) under conditions of androgen replacement. After reverse transcription of the RNA samples, the expression of BMP-7 was measured by real-time quantitative polymerase chain reaction (PCR). Glyceraldehyde phosphate dehydrogenase (GAPDH) was used as an internal standard.

RESULTS

The level of BMP-7 expression was highest in the normal prostate glandular tissue (P < 0.05). The expression of BMP-7 tended to be lower during the development and progression of prostate cancer. The expression of BMP-7 in prostate epithelial cells treated with 10(-7) M dihydrotestosterone (DHT) was significantly higher than in the DHT-free control (P = 0.0285).

CONCLUSIONS

It has been reported that the BMP-7 mRNA level is androgen-dependent in the mouse prostate. The present results suggest that the BMP-7 mRNA level is androgen-dependent in the human prostate, since the expression of BMP-7 was decreased in local recurrent prostate cancer tissues after hormonal therapy and was increased by DHT.

Nonandrogenic mediators of prostatic growth

Prostate growth and development are primarily under the control of androgens; however, other factors can also influence prostatic growth through alternative pathways. This article discusses some of the major nonandrogenic mediators of prostate growth. Information on the pathways by which these factors exert their effects is also reviewed.

Preliminary results comparing the recovery of basic fibroblast growth factor (FGF-2) in adipose tissue and benign and malignant renal tissue

PURPOSE

Basic fibroblast growth factor (bFGF or FGF-2) is mitogenic to numerous epithelial, mesodermal and endothelial cells, and thus may play a role in the neovascularity and progression of several tumors. Furthermore, FGF-2 is reported to be elevated in the serum and urine of patients with various cancers, including renal cancer. Obesity, with increased body fat, is a risk factor for renal cancer through unknown mechanisms. Since adipose tissue is a source of FGF-2, we determined the quantity and quality of activity of FGF-2 in omental adipose tissue and compared it to normal and cancerous renal tissue.

MATERIALS AND METHODS

Using heparin-Sepharose chromatography we extracted proteins from human omental adipose tissue, renal cell carcinoma (RCC) and benign renal tissue (BRT). Using FGF-2 antisera we performed western blot analysis to confirm their homology to FGF-2. We also assessed recovery, mitogenicity and angiogenicity of each of the proteins using thymidine incorporation into human umbilical vein endothelial cells (HUVEC) and the chorioallantoic membrane (CAM) assay.

RESULTS

Each of the three purified mitogenic proteins eluted with NaCl concentrations between 1.4 M. and 1.8 M., similar to control FGF-2. There was greater recovery of FGF-2 from omental adipose tissue compared with renal cell carcinoma or benign renal tissue (42 microg. vs. 24 microg. and 18 microg., respectively; ANOVA p <0.05). Moreover, FGF-2 from adipose tissue had greater mitogenic activity (96.% versus 68% and 38%; p <0.05) and greater angiogenic activity (5.5 vessels versus 2.7 and 1.6 vessels; p <0.05) on the CAM assay.

CONCLUSIONS

We suggest that human omental adipose tissue FGF-2 may demonstrate greater mitogenic and angiogenic activity than either benign or cancerous renal tissue FGF-2. It is not known if FGF-2 from adipose tissue may play a role in the relationship between obesity and renal cancer.

Androgen regulation of prostate cancer cell FGF-1, FGF-2, and FGF-8: preferential down-regulation of FGF-2 transcripts

Using quantitative RT-PCR, we found that T1 rat prostate cancer cell relative FGF-1 transcript content was about 180-fold greater than that of FGF-2. This difference in transcript content was not representative of T1 cell relative FGF-1 and FGF-2 protein content which showed, at most, only a 4- to 5-fold greater FGF-1 content. Testosterone caused time-dependent down-regulation of prostate cancer cell FGF-2 transcript content without influencing either FGF-1 or FGF-8 transcript content or T1 cell proliferation. Moreover, testosterone-mediated down-regulation of prostate cancer cell FGF-2 transcripts did not result in a statistically significant change in 21.5 or 17.0 kD FGF-2 isoform content. By contrast, an approximately 20% statistically significant decrement in 19.5 kD FGF-2 isoform content was demonstrable following 24 h testosterone treatment. However, following 72 h testosterone treatment, T1 cell 19.5 kD FGF-2 isoform content was not statistically significantly different from that of control. It is probable that the modest and variable decrement in 19.5 kD isoform content is not physiologically significant and is attributable to artifact resulting from difficulty quantifying this minor component of the FGF-2 isoforms. Transient transfection analysis showed that androgen caused concentration-dependent increases in MMTV-LTR regulated expression of chloramphenicol acetyl transferase activity. Consequently, the failure of androgen to affect either T1 cell FGF-1 and FGF-8 transcript content or T1 cell proliferation could not be attributed to defective androgen receptor function. Moreover, the absence of a close relationship between T1 cell FGF-2 transcript and FGF-2 protein content implies that FGF-2 transcript content is not the dominant determinant of prostate cancer cell FGF-2 protein content. Testosterone-mediated down-regulation of prostate-cancer-cell gene expression may have significance for clinical management of human disease that is treated by androgen ablation. The possibility that such ablation may enhance aggressiveness of "androgen-independent" cells by selective upregulation of gene expression merits further consideration.

Differences in prostate and adipose tissue basic fibroblast growth factor: analysis of preliminary results

OBJECTIVES

Basic fibroblast growth factor (bFGF or FGF-2) is mitogenic to human prostate epithelial and stromal cells, and it is reported to be elevated in the serum and urine of patients with various cancers, including prostate cancer. Obesity, with increased body fat, is a risk factor for prostate cancer through unknown mechanisms. Because adipose tissue is a source of FGF-2, we determined the quantity and quality of activity of FGF-2 in omental adipose tissue and compared it with normal and cancerous prostate tissues.

METHODS

Using heparin-Sepharose chromatography, we extracted proteins from human omental adipose tissue, adenocarcinoma of the prostate, and benign prostatic hypertrophic (BPH) tissues. Each of the mitogenic proteins eluted with NaCl concentrations between 1.4 M and 1.8 M, similar to control FGF-2. Using FGF-2 antisera (which inhibited the mitogenic activity of the proteins), we performed Western blot analysis to confirm their homology to FGF-2. We also assessed recovery, mitogenicity, and angiogenicity of each of the proteins using thymidine incorporation into human umbilical vein endothelial cells and the chorioallantoic membrane assay.

RESULTS

There was greater recovery of FGF-2 from omental adipose tissue compared with cancerous or BPH homogenates (40 micrograms [2.0 micrograms/g] versus 25 micrograms [1.25 micrograms/g] and 20 micrograms [1.0 microgram/g], respectively). Moreover. FGF-2 from adipose tissue had greater mitogenic activity (96.2% versus 74.8% and 54%; P < 0.05) and a greater angiogenic activity (5.1 vessels versus 2.9 and 1.8 vessels; P < 0.05) on the chorioallantoic assay.

CONCLUSIONS

We suggest that human omental adipose tissue FGF-2 may demonstrate greater mitogenic and angiogenic activity than either BPH or prostate cancer tissue FGF-2. It is not known whether FGF-2 from adipose tissue qualitatively or quantitatively may underlie the relationship between obesity and prostate cancer.

Effect of prostatic growth factor, basic fibroblast growth factor, epidermal growth factor, and steroids on the proliferation of human fetal prostatic fibroblasts

To study the relationship between androgen metabolism and the pathogenesis of benign prostatic hypertrophy, we purified a growth factor from benign hyperplastic tissue of human prostates and assayed the proliferative responses of human fetal prostatic fibroblasts to the purified growth factor (hPGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), dihydrotestosterone (DHT), and estradiol (E2). Prostatic tissue extracts were fractionated using heparin-Sepharose chromatography. The fraction that eluted with 1.3-1.7 M NaCl contained the majority of mitogenic activity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS/PAGE) of the lyophilyzed active fraction showed a band at 17,000 daltons. Human prostatic fibroblasts were isolated from fetal prostate and tested for their proliferative responses to hPGF, bFGF, EGF, DHT, and E2. hPGF, as well as bFGF and EGF, did increase tritiated thymidine incorporation into the cultured fibroblasts. DHT(10(-7) M) had a significant stimulatory effect on cell growth in serum-free media after 6 days of culture. E2(10-7 M) had no effect on cell proliferation. The combination of DHT and E2 showed no synergistic effect. We conclude that our purified hPGF, bFGF, and EGF promote cell growth directly, DHT indirectly, while E2 does not. The effect of DHT appears to be mediated via the increased production and/or secretion of growth factor(s). Possibly, the bFGF-like hPGF purified from human benign hyperplastic prostatic tissue is such a mediator.

Regulation of prostatic growth and function by peptide growth factors

Polypeptide growth factors are positive and negative regulators of prostatic growth and function. Expression and biological effects of epidermal growth factor (EGF), transforming growth factors (TGFs) alpha and beta, fibroblast growth factors (FGFs), and insulin-like growth factors (IGFs) in the prostate have been extensively studied. EGF and TGF alpha, which share the same receptor, are strong mitogens for prostatic epithelial and stromal cells. Their paracrine mode of action in normal tissue and early-stage tumors is apparently altered towards an autocrine stimulation in hormone-independent tumors, which gain the ability to produce TGF alpha by themselves. TGF beta has a dual role in the regulation of prostatic growth. It inhibits growth of prostatic epithelial cells in culture and mediates programmed cell death after androgen withdrawal. However, advanced prostatic carcinomas become insensitive to the inhibitory effect of TGF beta. Several members of the FGF family have been identified in the prostate. They are mainly or exclusively expressed in the stromal cells, and stimulate the epithelial cells. In the rat Dunning tumor model, progression is accompanied by distinct changes in the expression of FGFs and their receptors. In the hyperplastic tissue, basic FGF (bFGF) is accumulated. This growth factor is also a potent angiogenic inducer, expression of which may determine the metastatic capability of a tumor. IGFs are paracrine growth stimulators in the normal and hyperplastic prostate. It is still under consideration whether prostatic cancer cells gain the ability to produce IGF-I by themselves and thus shift to an autocrine mode of IGF-I stimulation. Growth factors also interact with the androgen-signaling pathway. IGF-I in particular, other growth factors as well, can activate the androgen receptor.

Influence of dihydrotestosterone, epidermal growth factor, and basic fibroblast growth factor on the cell kinetics of the PC3, DU145, and LNCaP prostatic cancer cell lines: relationship with DNA ploidy level

The cell kinetics (percentage of cells in the S+G2 phases of the cell cycle) and the DNA ploidy levels (nuclear DNA content) were determined in 108 samples each of the PC3, DU145, and LNCaP prostate cancer models. This was carried out by means of the digital cell image analysis of Feulgen-stained nuclei. Two to three hundred cell nuclei were analyzed for each of the 324 samples under study. The three cell lines were submitted to experimental conditions including the addition of dihydrotestosterone (DHT), epidermal growth factor (EGF), and basic fibroblast growth factor (bFGF), either alone or in combination, to the culture media. The results show that under the present culture conditions, the PC3 cell line was DHT-, EGF- and bFGF-insensitive. In contrast to what is generally reported in the literature, the DU145 cell line was DHT- and EGF-sensitive under the present culture conditions, but bFGF-insensitive. The LNCaP cell line was DHT-sensitive, but EGF- and bFGF-insensitive. While mainly tetraploid, the three cell lines nevertheless exhibited a significant level of heterogeneity in their nuclear DNA content distributions. Indeed, the proportions of non-tetraploid (diploid, hyperdiploid, triploid, hypertriploid, hypertetraploid, polymorphic) DNA histograms were 14% in the PC3, 16% in the DU145, and 29% in the LNCaP cell lines. These results suggest that the DNA ploidy level would not influence the hormone sensitivity level in the cell lines since they had significantly distinct hormone sensitivity profiles while remaining mainly tetraploid.

Demonstration of fibroblast growth factor receptor-I in human prostate by polymerase chain reaction and immunohistochemistry

The expression and localization of fibroblast growth factor receptor-1 were investigated in human prostatic tissues with or without benign hyperplasia. Using a polymerase chain reaction method, we were able to demonstrate that prostatic tissues with benign hyperplasia expressed a significantly higher level of fibroblast growth factor receptor-1 mRNA than normal prostatic tissues (P < 0.01 by Anova). Western blot analysis using an antiserum against the receptor gave 2 bands with molecular weights of about 140 kDa and 80 kDa; these correspond to the expected sizes of the long and secreted forms of the fibroblast growth factor receptor-1, respectively. An immunohistochemical study using the same antiserum further demonstrated that the immunoreactive staining occurred mainly in the basal cells of the glandular epithelium and occasionally in the stromal cells. These results suggest that fibroblast growth factors may influence, at least in part, the proliferation of the epithelial cells seen in benign hyperplasia of human prostate.

Urinary basic fibroblast growth factor in patients with bladder cancer and benign prostatic hypertrophy

OBJECTIVE

To investigate the role of urinary measurements of an angiogenic factor, basic fibroblast growth factor (bFGF), in the assessment of patients with bladder cancer.

PATIENTS AND METHODS

Urine from 83 patients was assayed using a commercially available ELISA for bFGF. Thirty-eight patients had a bladder tumour and 21 had a history of bladder cancer but no disease at the time of testing. Twenty-four patients acted as controls, 16 of whom were about to undergo transurethral resection of the prostate (TURP) for benign prostatic hypertrophy (BPH) and eight who had no urological disease.

RESULTS

Median urinary bFGF was higher in patients with active bladder cancer than in those with a clear cystoscopy (5.20 and 2.13 ng/g creatinine, respectively; P < 0.005). Median urinary bFGF was also elevated in patients about to undergo TURP (4.52 ng/g creatinine). Using a threshold value of 6.0 ng/g creatinine, the sensitivity of the test for detecting cancer was 42% and specificity was 88%. At a threshold value of 4.0 ng/g the sensitivity was 62% and the specificity 70%.

CONCLUSION

The relationship between urinary basic FGF and the presence of bladder cancer was significant. The test is not sufficiently sensitive or specific to use as a screening test for bladder cancer but may be very useful in monitoring the effectiveness of systemic therapies in bladder cancer. Elevated levels of bFGF in the urine of patients about to undergo TURP suggests a role for bFGF in the pathogenesis of BPH.

Age-related changes of the prostate gland in the senescence-accelerated mouse

Aging is of utmost importance in the pathogenesis of the prostate gland (i.e., benign prostate hyperplasia or prostatic carcinoma). The object of this study was to examine the morphological and histological changes of the aging prostate of the so-called senescence-accelerated mouse (SAM). Ventral and dorsolateral lobes of prostate glands of SAM were microdissected into two-dimensional ductal arrays. Gross morphology, ductal branching patterns, and histology were examined in these microdissected specimens. Wet weight and numbers of ductal tips in ventral and dorsolateral prostate glands in senescence accelerated-prone (SA-P) mice were significantly smaller than those of senescence accelerated-resistant (SA-R) mice, although the changes of patterns of gross ductal morphology were virtually identical in these groups. High incidence of stromal hyperplasia with fibrosis and inflammation was observed in the dorsal lobe of the aged SA-P mouse. Atypical glandular epithelial cells and cribriform glandular deformity were observed in the dorsal and lateral lobe of aged SA-P mice. Marked heterogeneity in age-related pathological changes was observed between prostatic lobes. These data suggest that the aging process occurs heterogeneously within the prostate gland, and that SA-P mice may be an important model for the study of age-related changes in the prostate gland.

Benign prostatic hyperplasia in a transgenic mouse: a new hormonally sensitive investigatory model

Recent advances in molecular biology have enabled incorporation of proto-oncogenes into the mouse germline. In this study we use a transgenic mouse line that overexpresses the fibroblastic growth factor (FGF) family member, int-2, under the control of mouse mammary tumor virus (MMTV) regulatory elements. One of the tissues targeted by MMTV is the mouse prostate. Expression of the MMTV-int-2 transgene in male transgenic mouse carriers results in a dramatic enlargement of the prostate gland which on histologic examination closely resembles the epithelial/glandular BPH observed in human and canine models. Pre- and postpubertal transgenic (NR) and wild-type (WT) FVB/N male mice were evaluated for the effects of hormonal manipulation by orchiectomy and orchiectomy followed by androgen replacement. Orchiectomy results in a significant decrease in size of the prostate in both NR and WT mice (p < 0.05), regardless of sexual maturity. Exogenous hormonal replacement with testosterone or dihydrotestosterone following orchiectomy results in significant regrowth of the prostate in both NR and WT mice. Flutamide, a potent nonsteroidal anti-androgen, resulted in a 55% reduction in size of the NR prostate (p < 0.002) and a similar 44% reduction in size of the WT prostate. Similarly, treatment of both NR and WT mice with leuprolide, a GnRH agonist, resulted in a significant decrease in prostate size (p < 0.05). Treatment of both NR and WT mice with finasteride (MK-906), a 5-alpha reductase inhibitor, failed to produce any significant regression in prostatic tissue. Based upon these data, we conclude that this transgenic mouse model, expressing int-2, produces an epithelial BPH histologically similar to other animal models. This transgenic model is hormonally sensitive and appears to represent a unique model for the investigation of BPH and growth factor induced epithelial cell hyperplasia.

Endocrine therapy of advanced carcinoma of the prostate

Increasing evidence suggests that growth of the prostatic tissue is regulated by a network of hormones and growth factors, in which androgens play the prominent role. Hormonal manipulation remains the core of treatment for locally advanced and metastatic prostate cancer. Achievement of a complete androgen blockade, by surgical or medical means or a combination of both, offers superior results in palliative management of advanced disease. Management of hormonal refractory cancer, however, remains a challenge to clinicians.

Transgenic models for the study of prostate cancer

Transgenic model systems provide tools for obtaining information that clarifies important relationships between genetic alterations and carcinogenesis. One such relationship is the induction of specific growth factor activities by dominantly acting oncogenes. Using a "transgenic organ" model referred to as mouse prostate reconstitution (MPR) under conditions where the ras and myc oncogenes were introduced using a recombinant retrovirus into both the mesenchymal and epithelial compartments of the urogenital sinus, poorly differentiated prostate cancer (PC) was produced with high frequency (> 90%) in inbred C57BL/6 mice. Time-course studies using northern blotting and immunohistochemical analysis showed that the transition from benign to malignant status invariably was associated with the induction of elevated transforming growth factor-beta 1 (TGF-beta 1) expression. Additional immunohistochemical analysis of TGF-beta 1 in human PC and benign prostatic hyperplasia (BPH) showed that positive extracellular staining was significantly more extensive in PC compared with BPH. This differential staining pattern was evident in focal areas of PC adjacent to BPH. These findings in both the MPR model system and human PC suggest that elevated TGF-beta 1 expression is involved in the progression to malignancy and that its pattern of expression may become a useful marker of PC. Additional studies using transgenic animal models will continue to provide important clinically useful information about PC in man.

Expression of bone morphogenetic proteins in human prostatic adenocarcinoma and benign prostatic hyperplasia

There are important interactions between prostatic tumours and bone. This study was designed to examine whether prostatic tissue can express bone inductive factors, in particular, the Bone Morphogenetic Proteins (BMPs). The polymerase chain reaction (PCR) has been used to screen for the expression of BMPs one to six in the prostatic tissue of patients with benign prostatic hyperplasia (BPH), non-metastatic prostatic adenocarcinoma and metastatic prostatic adenocarcinoma. BMPs were expressed in both benign and malignant prostate tissue and in the prostate tumour cell lines, PC3 and DU145. BMPs were also expressed in ocular melanoma tissue, a tissue which rarely metastasizes to bone. BMP-6 expression was detected in the prostate tissue of over 50% of patients with clinically defined metastatic prostate adenocarcinoma, but was not detected in non-metastatic or benign prostate samples or in ocular melanoma tissue. These findings suggest that the BMPs may play a role in the osteoinductive activity of prostate metastases and that the pattern of expression of BMPs may be important in the pathogenesis of osteoblastic metastases associated with prostate adenocarcinoma.

Growth factors in urologic tissues: detection, characterization, and clinical applications

During the last two decades, enormous strides have been made in understanding cellular and molecular biology. The direction of treatment of many neoplasms and other diseases are starting at the microscopic level. Growth factors are polypeptides that play a part in the development and maintenance of living tissues. We, as well as others, have investigated the role that growth factors play particularly in urologic tissues, both benign and malignant. We review several well-known growth factors and their function in prostate, kidney, and bladder tissues, as well as their functions in other regulating processes of the human body, and also the use of growth factors as tumor markers, and antibodies to growth factors as possible treatment of disease.

Regulation of fibroblast growth factor-like protein(s) in the androgen-responsive human prostate carcinoma cell line LNCaP

Growth of the normal and malignant prostate is known to be regulated by androgens. Part of their effect has been suggested to be mediated through coordinated regulation of secreted growth factors with autocrine function. We now examine the biological role of preferentially paracrine acting factors in growth control of prostate cancer, i.e. fibroblast growth factor(s) (FGF). Coculture experiments using the androgen-responsive human prostate carcinoma cell line LNCaP as feeder cells and the FGF-dependent human adrenal carcinoma SW-13 cell line as target cells show that (i) LNCaP cells induce growth of SW-13 cells, (ii) even higher stimulation of SW-13 cells is seen in the presence of androgen treated LNCaP cells and (iii) a specific anti-bFGF antibody inhibits growth of SW-13 cells induced by androgen treated LNCaP cells; no proliferation of SW-13 cells occurs in the absence of LNCaP cells. Partial purification of the secretory products of LNCaP cells was performed by affinity chromatography using a heparin sepharose column. Fractions were tested for biological activity in a soft agar assay with SW-13 cells. Several activities could be detected, the main activity was eluted with about 1.5 M NaCl. These data suggest that androgen treatment of LNCaP cells leads to enhanced secretion of proteins which belong to the FGF-family.

Human prostatic cancer cell derived growth factor stimulating fibroblasts and its mechanisms

A human prostatic cell line JCA-1 has been shown to release into culture medium an activity that promotes the proliferation of murine fibroblast 3T3 cells. The presence of additional serum-free conditioned culture supernatant from JCA-1 cells accelerates the 3T3 growth rate as determined by cell counts, [3H]thymidine uptake into DNA and colony formation in soft agar gel. The growth activity was determined not to derive from culture medium components. Treatment of JCA-1 cells with RNA synthesis inhibitor actinomycin D abrogated the activity, indicating that protein synthesis is required for the presence of this activity from JCA-1 cells. The molecular mass of this prostatic cell derived growth factor (PRGF) was larger than 10,000 KDa, and its interaction with fibroblasts resulted in an approximate 27 percent increase in replicating cell cycle phases S and G2M with a reciprocal decrease of G1 cells. These data indicated a mechanism causing a more rapid entry of cells into replication. The interaction between prostatic cancer cells and related tissues and their relation to pathogenesis is reviewed.

The effects of basic fibroblast growth factor and suramin on cell motility and growth of rat prostate cancer cells

Suramin, a new type of cancer chemotherapeutic agent with growth factor antagonist properties, has been reported to affect growth of prostate cancer metastatic lesions. Partin et al. have previously reported that prostate cancer cell motility was essential for tumor cell metastasis. We have studied the effects of suramin on cell motility and cell growth in a prostate cancer cell model. We have demonstrated that suramin has differential effects on rat prostate cancer cells in vitro. The effects of suramin on cell growth were biphasic. At low concentrations of 0.01 mM and 0.1 mM, suramin stimulated growth while it was inhibitory at a higher concentration of 1.0 mM, and 10 mM suramin resulted in cell death. Cell motility was inhibited at a suramin concentration above 0.1 mM. The inhibition of cell motility by suramin may be through the blockage of growth factor effects. Reducing serum growth factor concentration reduced cell motility and the motility was restored by the addition of basic fibroblast growth factor (bFGF) to the media. Motility which had been restored by bFGF could then be blocked by the presence of suramin. The inhibition of cell motility by suramin is reversible on washout of the drug. Suramin inhibits cell motility in both the human prostate cancer cells (LNCaP) and the rat (MLL).

Purification of acidic fibroblast growth factor from bovine omentum

Two heparin binding growth factors with different molecular weight, 16.6 kD and 18.6 kD polypeptide, were purified from bovine omentum. The two factors have almost the same affinity to heparin; they were eluted with 1.0 M NaCl from the affinity column. The 16.6 kD polypeptide was found to be acidic fibroblast growth factor by amino acid sequence analysis. The 18.6 kD polypeptide was an N-terminus blocked polypeptide and was suggested to be beta-endothelial cell growth factor. These molecular species may play significant roles in maintaining vascularized structure in omentum and be related to the angiogenic activity of the tissue.

A form of basic fibroblast growth factor is secreted into the adluminal fluid of the rat coagulating gland

Rat coagulating gland and its secreted fluid contain a mitogenic substance that, by numerous criteria, appears to be similar to basic fibroblast growth factor (basic FGF). It is a potent competence factor in the BALB/c3T3 mouse embryo fibroblast assay, elutes from heparin-agarose at concentrations of NaCl greater than 1.0 M, and has an isoelectric point (pI) between 8 and 9. In coagulating gland fluid, its molecular weight was 20,000 +/- 5,000, as indicated by gel filtration on Sephadex G-200. Western blot analysis of purified factor from coagulating gland cytosol and fluid, respectively, revealed immunoreactive bands of 16,000 and 17,000 relative molecular weight similar to that of purified bovine basic FGF.