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Biomedical subjects

J C Romijn

Publications and source records attributed to J C Romijn.

At least 19 recordsLinked to original sources

Clinical correlates of the biological variation of sperm DNA fragmentation in infertile men attending an andrology outpatient clinic.

Determination of sperm DNA fragmentation, as assessed by the sperm chromatin structure assay (SCSA), has become an important tool for the evaluation of semen quality. The aim of the present study was to describe the biological variation of sperm DNA fragmentation in men attending an andrology clinic and to identify clinical correlates of the biological variation of sperm DNA fragmentation. For this study, two consecutive semen samples from 100 patients attending our andrology outpatient clinic were subjected to semen analysis, performed in parallel according to WHO guidelines and by SCSA. A good agreement between pairs of samples was found for SCSA-derived variables, as indicated by a significantly lower median coefficient of variation (CV) of the DNA Fragmentation Index (DFI) and the high DNA stainability (HDS) compared with WHO semen parameters. In half of the men attending our andrology clinic, however, the individual biological variation of DFI and HDS, expressed as CV of two samples, exceeded 10%. Dysregulation of spermatogenesis, as seen as testicular insufficiency or varicocele, was not associated with increased variability of DFI or HDS. A backward multiple linear regression analysis, however, indicated that the biological variation of DFI may be more profound in men with characteristics of normal spermatogenesis. In conclusion, we confirm previous reports that sperm DNA fragmentation has a lower biological variability than classical semen parameters. We hypothesize that the sperm chromatin structure may be more influenced in patients with normal spermatogenesis, whereas in men with disturbed spermatogenesis, the chromatin structure may be already so impaired that the effect of unidentified factors leading to variability of sperm DNA fragmentation in time may not be as profound.

Chromatin↗

Clinical laboratory evaluation of male subfertility.

Male subfertility is a common problem with a complex etiology, requiring a complete andrological work-up for proper diagnosis. The male reproductive tract is controlled by a well-balanced hormonal system, in which hypothalamic (GnRH), pituitary (LH, FSH) and testicular hormones (androgens, inhibin B) participate. Any disturbance of this hormonal system may therefore lead to testicular dysfunction and interfere with the spermatogenesis process. In addition, also other components along the ductal system, such as epididymis, prostate and seminal vesicles, that improve sperm fertility by contributing their secretions to the semen, might function inadequately and thus fail to enhance the fertilizing capacity of the sperm cells. External factors (heat, chemicals, life style) and anatomical abnormalities (varicocele) were shown to have a negative influence on male fertility. In a number of patients genetic defects can be identified as the cause of their infertility. Laboratory tests are available to assess hormone concentrations, semen composition, accessory gland function and sperm cell function. Conventional semen analysis includes the determination of sperm concentration, semen volume, sperm motility (qualitative and quantitative), sperm morphology, sperm cell vitality, pH, leucocytes and antibodies. The usefulness of the determination of these parameters as predictor of fertility appears to be rather limited, however. Therefore, alternative tests, some based on more functional aspects (sperm penetration, capacitation, acrosome reaction), have been developed. Furthermore, there is an increasing attention for the assessment of DNA integrity, for instance by the flowcytometer-based Sperm Chromation Structure Assay (SCSA), as an additional or alternative parameter of sperm quality. It is likely and desirable that further assays with better predictive value are being developed in the near future.

Fertilization↗

Polyamines and prostatic cancer.

The importance of polyamines in prostatic growth and differentiation has prompted studies to evaluate the clinical relevance of the ornithine decarboxylase/polyamine system in prostatic cancer. These studies show that differences in biological behaviour of prostatic (cancer) cells are associated with changes in polyamine levels and/or the activity of their metabolic enzymes. Faulty antizyme regulation of polyamine homoeostasis may play an important role in the growth and progression of prostatic carcinoma. Treatment of human prostate carcinoma cells with inhibitors of polyamine metabolic enzymes or polyamine analogues induces cell growth arrest or (apoptotic) cell death. Our recent in vitro studies using conformationally restricted polyamine analogues show that these compounds inhibit cell growth, probably by inducing antizyme-mediated degradation of ornithine decarboxylase. Sensitivity of human prostate cancer cells for these compounds was increased in the absence of androgens. These results suggest that these analogues might have chemotherapeutic potential in case prostatic cancer has become androgen-independent. Pilot data in an in vivo model show that these analogues have effects on tumour cell proliferation, vascularity, blood perfusion and tissue hypoxia. Overall, these studies show that polyamines may serve as important biomarkers of prostatic malignancy and provide a promising target for chemotherapy of prostatic cancer.

Antineoplastic Agents↗

Use of nude mouse xenograft models in prostate cancer research.

BACKGROUND: Our understanding of the mechanisms of (progressive) growth of prostatic cancer has been largely obtained through the study of experimental animal models. To be able to validate new concepts, representative model systems of human origin that mimic the clinical process of the disease in patients are essential. Unfortunately, the limited number of human prostate tumor models has considerably hampered research. METHODS: Various research groups have put much effort in the development of human prostate tumor xenograft models, and large numbers of clinical prostate tumors were heterotransplanted in immune-deficient host animals. This huge effort has resulted in a number of tumor lines which are reviewed here. RESULTS: Up to now, approximately 25 xenograft models of human prostate cancer have been established and reported in the literature. The available xenografts seem to represent the various stages of clinical prostate cancer, such as early progression and transition from androgen-dependent to androgen-independent growth. In addition, recent efforts are concentrating on the establishment of in vitro cell lines from these xenografts as well as on the development of (bone) metastatic variants. CONCLUSIONS: Xenograft models are important for elucidating regulatory pathways of tumor growth and progression and are indispensible for testing of new treatment modalities.

Animals↗

Androgen-independent growth is induced by neuropeptides in human prostate cancer cell lines.

BACKGROUND: Androgen-independent growth leads to progressive prostate cancer after androgen-ablation therapy. This may be caused by altered specificity of the androgen receptor (AR), by ligand-independent stimulation of the AR, or by paracrine growth modulation by neuropeptides secreted by neuroendocrine (NE) cells. METHODS: We established and characterized the androgen-independent FGC-DCC from the androgen-dependent LNCaP fast growing colony (FGC) cell line. The androgen-independent DU-145, FGC-DCC, and PC-3, and the androgen-dependent LNCaP and PC-346C cell lines were used to study growth modulation of gastrin-releasing peptide (GRP), calcitonin (CT), serotonin (5-HT), and vasoactive intestinal peptide (VIP) by (3)H-thymidine incorporation. Specificity of the growth-modulating effects was tested with the anti-GRP monoclonal antibody 2A11 and induction of cAMP by neuropeptides. RESULTS: Androgen-independent growth stimulation by neuropeptides was shown in DU-145 and PC-346C. 2A11 inhibited GRP-induced (3)H-thymidine incorporation in DU-145 and PC-346C and inhibited proliferation of the FGC-DCC and PC-3 cell lines. With some exceptions, cAMP induction paralleled growth stimulation. Dideoxyadenosine (DDA) inhibited the GRP-induced growth effect in DU-145 and PC-346C, whereas oxadiazoloquinoxaline-1-one (ODQ) had no effect on (3)H-thymidine incorporation. None of the neuropeptides stimulated growth of LNCaP, FGC-DCC, or PC-3. CONCLUSIONS: GRP-induced growth of DU-145 and PC-346C was specific and cAMP-mediated. Androgen-independent growth of FGC-DCC cells was mainly due to an induction of Bcl-2 expression and possibly through the activation of an autocrine and NE-like pathway, as has been shown also for the PC-3 cell line. Growth induction of non-NE cells by neuropeptides could be a possible role for NE cells in clinical prostate cancer.

Androgens↗

Identification of hyaluronan as a crystal-binding molecule at the surface of migrating and proliferating MDCK cells.

BACKGROUND: The adherence of calcium oxalate crystals to the renal tubule epithelium is considered a critical event in the pathophysiology of calcium nephrolithiasis. Calcium oxalate monohydrate (COM) crystals cannot adhere to the surface of a functional Madin-Darby canine kidney (MDCK) monolayer, but they bind avidly to the surface of proliferating and migrating cells. METHODS: To identify crystal-binding molecules (CBMs) at the surface of crystal-attracting cells, we applied metabolic labeling protocols in combination with differential enzymatic digestion and gel filtration, which was compared with [14C]COM crystal binding and confirmed by confocal microscopy. RESULTS: The indication that hyaluronan [hyaluronic acid (HA)] might act as a CBM in subconfluent cultures came from studies with glycosaminoglycan (GAG)-degrading enzymes. Subsequently, metabolic-labeling studies revealed that hyaluronidase cleaved significantly more radiolabeled glycoconjugates from crystal-attracting cells than from cells without affinity for crystals. During wound repair, crystal binding could be prevented by pretreating the healing cultures with hyaluronate lyase, an enzyme that specifically hydrolyzes HA. Binding to immobilized HA provided evidence that COM crystals physically can become associated with this polysaccharide. Finally, confocal microscopy demonstrated that fluorescently labeled HA binding protein (HABP) adhered to the surface of proliferating cells in subconfluent cultures as well as to cells involved in closing a wound, but not to cells in confluent monolayers. CONCLUSIONS: These results identify HA as binding molecule for COM crystals at the surface of migrating and proliferating MDCK cells.

Animals↗

Sialic acid and crystal binding.

BACKGROUND: We studied the role of cell surface sialic acid in the adherence of calcium oxalate monohydrate (COM) crystals to Madin-Darby canine kidney (MDCK) cells. METHODS: Studies were performed with undifferentiated (crystal-binding) cells in subconfluent cultures and maturated (noncrystal-binding) cells in confluent cultures. Lectins were used to study the emergence and abundance of oligosaccharides at the cell surface during epithelial development. The effect of neuraminidase treatment on crystal binding was studied with [14C]COM crystals, and the enzyme-induced release of cell surface-associated sialic acid molecules was monitored by labeling the cells metabolically with [3H]glucosamine. RESULTS: Binding studies with lectins derived from Maackia Amurensis II (MALII) and Sambucus Nigra (SNA) demonstrated that the cells expressed terminal sialic acids attached to penultimate galactose through alpha 2,3 and alpha 2,6 bonds at different stages of epithelial development. Neuraminidase treatment strongly reduced the affinity of the cell surface for COM crystals in subconfluent cultures. Nevertheless, neuraminidase cleaved more sialic acids from cells in confluent cultures than from those in subconfluent cultures. Peanut agglutinin (PNA), which binds only to sialylated terminal galactose units, adhered to developing but not to maturated cells, unless the latter were pretreated with neuraminidase. Both results indicate that the surface of maturated MDCK cells is more heavily sialylated than that of undifferentiated cells. Free sialic acid molecules showed little or no affinity for COM crystals and did not affect the adherence of the crystals to undifferentiated cells. CONCLUSIONS: There are at least two models that may explain these results. First, sialic acids are presented at the surface of immature cells in an orientation that specifically matches crystal surface characteristics favoring crystal-cell interactions. Second, sialic acid molecules are not directly associated with the crystals, but may be involved in the exposure of another crystal binding molecule at the cell surface.

Animals↗

An Sp1 binding site is essential for basal activity of the human prostate-specific transglutaminase gene (TGM4) promoter.

Human prostate-specific transglutaminase (hTG(P)) is a cross-linking enzyme encoded by the TGM4 gene. The TGM4 gene promoter was characterized by deletion mapping and mutational analysis. Promoter constructs, containing the minimal promoter requirements, could efficiently drive transcription in the prostate cancer cell lines PC346C and LNCaP and the hepatic cancer cell line Hep3B. The region between positions -113 and -61 was demonstrated to be essential for core promoter activity. Further analysis revealed the functional importance of an Sp1 binding motif, 5'-ACCCCGCCCC-3', at positions -96 to -87. This sequence is a binding site of the ubiquitous transcription factors Sp1 and Sp3.

Base Sequence↗

Down-regulation of CD44 expression in human prostatic carcinoma cell lines is correlated with DNA hypermethylation.

Down-regulation of the cell-surface adhesion molecule CD44 has been suggested to play an important role in tumor progression and metastasis of prostate cancer. CD44 is encoded by a gene that contains a CpG-rich region (CpG island) in its 5' regulatory sequence. We tried to assess whether hypermethylation of this region is the mechanism responsible for CD44 transcriptional inactivation. A panel of prostatic-carcinoma cell lines, Du145, LNCaP, PC3, PC346C and TSU, was analyzed for CD44 mRNA and protein expression. Du145, PC3 and TSU were positive for CD44, whereas in LNCaP and PC346C both CD44 mRNA and protein expression was suppressed. Methylation-sensitive restriction-enzyme analysis of genomic DNA showed that, in contrast to the CD44-positive cell lines, the CD44-negative lines were hypermethylated in the CD44 promoter CpG island. Furthermore, treatment of a PC346C culture with the demethylating agent 5-azacytidine resulted in re-expression of CD44 mRNA. It is concluded that hypermethylation of the CD44 5' promoter region is one of the mechanisms by which CD44 expression is down-regulated in prostatic-carcinoma cell lines.

Antimetabolites, Antineoplastic↗

Characterization of chromosome 8 aberrations in the prostate cancer cell line LNCaP-FGC and sublines.

In two androgen-dependent (FGC and P70) and two androgen-independent (LNO and R) sublines of the prostate cancer model LNCaP numerical and structural aberrations of chromosome 8 were investigated in detail. The techniques used were whole chromosome paint (WCP) and fluorescence in situ hybridization (FISH) with three cosmid probes mapping to different parts of the p-arm (D8S7 (8p23.3), LPL (8p22) and PLAT (8p11.1)). By WCP all four cell lines showed four copies of chromosome 8 in most cells. However, FISH demonstrated that in all sublines deletions in the 8p region were present. The majority of both FGC and P70 had two copies of cosmids D8S7 and LPL. The cosmid PLAT showed a broader distribution (1-4 copies), especially in P70. Compared with FGC and P70, both LNO and R showed a larger number of copies (3 or 4) of all three cosmid loci. It is discussed that this difference is probably the result of nondisjunction as a reaction to loss of other sequences on 8p, possibly the tumor suppressor gene (TSG) mapping to 8p21. The fact that both sublines LNO and R are androgen-independent raises the possibility of a link between TSG loss on 8p and androgen independence.

Chromosome Aberrations↗

LLC-PK1 cells as a model system to study proximal tubule transport of water and other compounds relevant for renal stone disease.

LLC-PK1 cells were cultured on a permeable support in a two-compartment culture system. Confluent monolayers received an ultrafiltrate-like solution at the apical side and a plasma-like solution at the basolateral side. The distribution of various solutes, including phosphate, calcium, and oxalate over both compartments was measured in time. The transport of water was monitored by alterations in fluid concentrations of radiolabeled inulin. Bicarbonate, glucose, and phosphate were transported rapidly from the apical to basolateral side of the monolayer. Sodium and chloride were reabsorbed without major consequences for the osmolality in the apical and basal fluid. Calcium and potassium were also reabsorbed, but to a smaller extent than sodium. The luminal concentration of oxalate gradually increased to values that were at least three times higher (12.0+/-0.4 micromol/l) than those in the contraluminal fluid (3.8+/-0.1 micromol/l). However, since the luminal rise of oxalate completely matched the rise of inulin in the apical fluid this appeared to be the passive consequence of active water reabsorption rather than of net directed oxalate transport. The LLC-PK1 model could prove useful to study the regulation of proximal tubule water transport and its effect on luminal stone salt concentrations under different physiological conditions.

Animals↗

Chemosensitivity of prostate cancer cell lines and expression of multidrug resistance-related proteins.

The aim of this study was to obtain insight into the role of the multidrug resistance (MDR) phenomenon in hormone-independent progressive prostate cancer. Using immunocytochemistry and Western blotting we determined the expression of P-glycoprotein (Pgp), multidrug resistance-associated protein (MRP), glutathione-S-transferase-pi (GST-pi), Bcl-2, Bax, topoisomerase (Topo) I, II alpha and II beta in the human prostate cancer cell lines PC3, TSU-Pr1, DU145 and LNCaP derivatives LNCaP-R, LNCaP-LNO and LNCaP-FGC. Proliferative activity was assessed by immunocytochemistry. MTT assays were used to determine the sensitivity to etoposide, doxorubicin and vinblastin. Pgp was not expressed in any of the cell lines. MRP was variably expressed. GST-pi was expressed in TSU-Pr1, PC3 and DU145. The expression of Bcl-2 was restricted to TSU-Pr1, whereas Bax was found in all cell lines. Topo II alpha was expressed at the highest level in the rapidly proliferating cell lines TSU-Pr1 and DU145. Topo I and II beta were equally expressed. Resistance profiles varied among the cell lines, with TSU-Pr1 being the most sensitive and LNCaP-LNO relatively resistant. Multiple MDR proteins were expressed in prostate cancer cell lines and may well influence response to chemotherapy. Future functional studies, using chemo-selected MDR models, may further help to determine the mechanism or combination of mechanisms underlying the resistance of prostate cancer to chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Cell type-specific acquired protection from crystal adherence by renal tubule cells in culture.

BACKGROUND: Adherence of crystals to the surface of renal tubule epithelial cells is considered an important step in the development of nephrolithiasis. Previously, we demonstrated that functional monolayers formed by the renal tubule cell line, Madin-Darby canine kidney (MDCK), acquire protection against the adherence of calcium oxalate monohydrate crystals. We now examined whether this property is cell type specific. The susceptibility of the cells to crystal binding was further studied under different culture conditions. METHODS: Cell-type specificity and the influence of the growth substrate was tested by comparing calcium oxalate monohydrate crystal binding to LLC-PK1 cells and to two MDCK strains cultured on either permeable or impermeable supports. These cell lines are representative for the renal proximal tubule (LLC-PK1) and distal tubule/collecting duct (MDCK) segments of the nephron, in which crystals are expected to be absent and present, respectively. RESULTS: Whereas relatively large amounts of crystals adhered to subconfluent MDCK cultures, the level of crystal binding to confluent monolayers was reduced for both MDCK strains. On permeable supports, MDCK cells not only obtained a higher level of morphological differentiation, but also acquired a higher degree of protection than on impermeable surfaces. Crystals avidly adhered to LLC-PK1 cells, irrespective of their developmental stage or growth substrate used. CONCLUSIONS: These results show that the prevention of crystal binding is cell type specific and expressed only by differentiated MDCK cells. The anti-adherence properties acquired by MDCK cells may mirror a specific functional characteristic of its in situ equivalent, the renal distal tubule/collecting ducts.

Animals↗

Human prostate-specific transglutaminase: a new prostatic marker with a unique distribution pattern.

Human prostate-specific transglutaminase (hTGp) is a cross-linking enzyme, the physiologic function of which has not been established unequivocally yet. To gain insight into its distribution, we raised antisera against hTGp. By using Western blotting analysis, we found that these antisera specifically recognize a 77-kDa protein in prostatic fluids, seminal plasmas, and prostatic tissues. The concentrations of hTGp in these fluids and tissues were found to be highly variable among individuals. Immunohistochemical examination of several formalin-fixed paraffin-embedded human tissues revealed an exclusive expression in the prostate. The histologic localization and distribution of hTGp within the prostate was assessed by studying multiple sections from tumor-containing prostatectomy specimens and needle biopsies. hTGp expression was entirely restricted to luminal epithelial cells. No basal epithelial cells or stromal cells were stained. Within the prostate, large areas without any hTGp-positive cells were seen. Immunopositive cells were present either in a scattered pattern or concentrated in single or multiple glands in which all luminal epithelial cells expressed hTGp. The latter staining pattern occurred frequently, but not exclusively, in the peripheral zone, whereas scattered expression was most often observed in the transitional zone. Expression of the hTGp protein could occasionally be observed in high-grade prostatic intraepithelial neoplasia, but was not detected in prostate carcinoma cells. The expression pattern as observed for hTGp has not been found thus far for any other prostate-specific marker.

Androgen-Binding Protein↗

Attachment sites for particles in the urinary tract.

The adherence of crystals to the surface of renal tubule epithelial cells is one of the initial events in the development of nephrolithiasis. The accumulation of crystalline material in the kidney will sooner or later result in the formation of a stone. Calcium crystals occasionally are present in the urine of even healthy individuals, and mechanisms responsible for the selective attachment of crystals to the tubular epithelium of stone-forming individuals must exist. Although several types of cell surface molecules, including phosphatidylserine (PS) and sialic acid, have been proposed as receptors for crystals in the tubular system, the exact nature of these crystal-binding sites has not yet been revealed. Previously, it was demonstrated that calcium oxalate monohydrate crystals adhere to subconfluent, but not to confluent, Madin-Darby canine kidney-I cultures. This model was used here to investigate whether the surface of cells with affinity for crystals is enriched with one of the proposed crystal-binding molecules. Annexin V was used for the detection of PS at the cell surface, and Sambucus nigra lectin was used to reveal terminal sialic acid in a (alpha2,6) linkage to galactose units. FITC-annexin V binding studies showed that PS was not exposed at the surface of proliferating or growth-inhibited cells, unless they were pretreated with an apoptosis-inducing cytotoxic agent. Sambucus nigra lectin binding, of which the specificity was confirmed by blocking with N-acetylneuraminyl-lactose, demonstrated the abundant presence of (alpha2,6)-linked sialic acid residues at the cell surface of both subconfluent and confluent cultures. While these results seem to rule out a role for PS in the adherence of calcium oxalate monohydrate crystals to the surface of maturating Madin-Darby canine kidney-I cells, they question the role for cell surface-associated sialylated glycoconjugates in this process.

Animals↗

The human prostate-specific transglutaminase gene (TGM4): genomic organization, tissue-specific expression, and promoter characterization.

Human prostate-specific transglutaminase (hTGP) is a cross-linking enzyme secreted by the prostate. In this study, we performed dot blot analysis of 50 normal human tissues to demonstrate unambiguously the prostate-specific expression of hTGP. Furthermore, we elucidated the genomic organization of the TGM4 gene, the gene encoding hTGP. The structure of this gene displays striking similarity to that of other transglutaminase (TGase) genes. The TGM4 gene spans approximately 35 kb of genomic DNA and consists of 13 exons and 12 introns. The main transcription initiation site is located 52 bp upstream of the translational start codon. A hTGP splice variant of intron 1 was detected. This splice variant contains an in-frame antisense Alu element insertion. The TGM4 promoter was analyzed by sequencing and transfection experiments. At positions -1276 to -563, the promoter harbors a cyclophilin pseudogene with 94% similarity to the cyclophilin A cDNA. Deletion mapping of the TGM4 promoter in the transiently transfected human prostate cancer cell line PC346C showed comparable activity of 2.1-, 1.5-, and 0.5-kb promoter fragments.

Amino Acid Sequence↗

Expression of prostatic factors measured by reverse transcription polymerase chain reaction in human papillomavirus type 18 deoxyribonucleic acid immortalized prostate cell lines.

OBJECTIVES: To investigate expression of the prostatic markers prostate-specific antigen (PSA), prostate-specific membrane antigen (PSM), and the androgen receptor (AR) after human papillomavirus (HPV) type 18 deoxyribonucleic acid (DNA) transfection and subsequent immortalization of human prostate epithelial cells. METHODS: Recently, two human prostate epithelial cell lines were established by HPV transformation: PZ-HPV-7, derived from normal peripheral zone (PZ) tissue, and CA-HPV-10, derived from high Gleason grade adenocarcinoma. Expression of PSA was studied by the reverse transcription polymerase chain reaction (RT-PCR), because in preliminary studies using immunocytochemistry and Northern blotting, no PSA expression was found. PSM was analyzed by RT-PCR and nested RT-PCR. These analyses included primary human prostate cell strains. Furthermore, androgen-supplemented methylthiazol tetrazolium (MTT) growth assays were performed and expression of AR was studied by immunocytochemistry. Prostate carcinoma cell lines LNCaP and PC-346C were included as positive controls and breast carcinoma cell line MCF-7 as a negative control. RESULTS: Both cell lines exhibited low levels of RNA for PSA and PSM in comparison with cell lines LNCaP and PC-346C. AR expression by immunocytochemistry was negative using monoclonal antibody F39.4 and polyclonal antibody SP-197. In an androgen-supplemented environment, growth rates of both HPV immortalized cell lines were not stimulated in contrast to LNCaP. CONCLUSIONS: RNA transcripts of PSA and PSM were detected by RT-PCR in HPV immortalized prostate epithelial cell lines PZ-HPV-7 and CA-HPV-10. The expression of prostate-specific markers may further validate the utility of this stepwise transformation model of human prostate carcinogenesis.

Antigens, Surface↗

Cytogenetic analysis of 39 prostate carcinomas and evaluation of short-term tissue culture techniques.

Karyotypic analysis was performed on 102 prostate cancer specimens which were obtained through radical prostatectomy, transurethral resection, or regional lymph node dissection. Short term tissue culture was applied in all cases. Of the media and growth factors evaluated, F12/DMEM, supplemented with 2% fetal calf serum, insulin, epidermal growth factor, hydrocortisone, and cholera toxin produced the largest increase of in vitro proliferation. Such in vitro cultured cells were all phenotypically acinar epithelial cells, the supposed targets for neoplastic transformation. Stromal cell growth appeared to be completely suppressed. Of the three culture techniques investigated, the method developed in Lund, Sweden, was the most successful: 11/15 cultures yielded metaphases and, in three of these, clonal aberrations were identified. All 39 karyotypes obtained essentially had a 46,XY karyotype with clonal aberrations (eight cases) and/or nonclonal aberrations (30 cases). Clonal structural aberrations involved 2p, 3q, 11p, 17p, and 21q. The clonal numerical aberrations found were: + 8, + dmin, and -Y. The most frequently observed nonclonal aberrations were 8p deletions (five cases) and loss of 6, 7, 8, 15, 17, 18, 21, and/or Y (> or = five cases). In summary, clonal aberrations were observed in 20% of the evaluable PC cell cultures, and nonclonal aberrations in 77%. So, although diploid cells without clonal abnormalities still had a growth advantage, under optimal conditions PC cells were able to proliferate in primary in vitro culture.

Carcinoma↗