Notch-mediated induction of N-cadherin and α9-integrin confers higher invasive phenotype on rhabdomyosarcoma cells.

BACKGROUND: Rhabdomyosarcoma (RMS) is the commonest type of soft-tissue sarcoma in children. Patients with metastatic RMS continue to have very poor prognosis. Recently, several works have demonstrated a connection between Notch pathway activation and the regulation of cell motility and invasiveness. However, the molecular mechanisms of this possible relationship remain unclear. METHODS: The Notch pathway was manipulated pharmacologically and genetically. The mRNA changes were analysed by quantitative PCR and protein variations by western blot and immunofluorescence. Finally, the capabilities of RMS cells to adhere, heal a wound and invade were assessed in the presence of neuronal cadherin (N-cadherin)- and α9-integrin-blocking antibodies. RESULTS: Cells treated with γ-secretase inhibitor showed lower adhesion capability and downregulation of N-cadherin and α9-integrin. Genetic manipulation of the Notch pathway led to concomitant variations in N-cadherin and α9-integrin. Treatment with anti-N-cadherin-blocking antibody rendered marked inhibition of cell adhesion and motility, while anti-α9-integrin-blocking antibody exerted a remarkable effect on cell adhesion and invasiveness. CONCLUSION: Neuronal cadherin and α9-integrin are postulated as leading actors in the association between the Notch pathway and promotion of cell adhesion, motility and invasion, pointing to these proteins and the Notch pathway itself as interesting putative targets for new molecular therapies against metastases in RMS.

A transcriptional signature associated with the onset of benign prostate hyperplasia in a canine model.

BACKGROUND: Benign prostatic hyperplasia (BPH) represents the most frequent proliferative abnormality of the human prostate. In spite of the well-characterized architectural development of BPH, little is known about the cellular and molecular events that contribute to it. METHODS: We have developed an animal model to evaluate the follow-up of hormone-induced BPH and the analysis of the gene expression associated with BPH. Immunohistochemistry on human patient samples validated the BPH-related molecular alterations. RESULTS: Canine specific Affymetrix microarray analysis performed on sequential biopsies obtained from a beagle dog dynamic model characterized a number of genes altered during the onset of BPH. In addition to the genes involved in calcification, matrix remodeling, detoxification, cell movement, and mucosa protection (MGP, MMP2, TIMP2, ITIH3, GST, MT2A, SULT1A1, FKBP1B, MUC1, STRBP, TFF3), the up-regulation of TGFB3 and CLU indicated a complete adjustment of the transdifferentiation, senescence and apoptosis programs. The up-regulation of Clusterin was validated by RT-qPCR and immunohistochemistry, both in the dog dynamic model and in human samples, further confirming the suitability of the animal model for the study of the molecular alterations associated with BPH. CONCLUSIONS: Transcriptome analysis performed on a dynamic animal model that accurately mimicked the human clinic, allowed us to characterize a gene expression pattern associated with the onset of BPH.

Novel molecular profiles of endometrial cancer-new light through old windows.

Endometrial carcinoma (EC) is the most common gynecological malignancy in the western world. A widely accepted dualistic model, which has been established on a morphological basis, differentiates EC into two broad categories: Type I oestrogen-dependent adenocarcinoma with an endometrioid morphology and Type II non-oestrogen-dependent EC with a serous papillary or clear cell morphology. Molecular genetic evidence indicates that endometrial carcinoma, as described in other malignancies, likely develops as the result of a stepwise accumulation of alterations in cellular regulatory pathways, such as oncogene activation and tumor suppressor gene inactivation, which lead to dysfunctional cell growth. These molecular alterations appear to be specific in Type I and Type II cancers. In type I endometrioid endometrial cancer, PTEN gene silencing in conjunction with defects in DNA mismatch repair genes, as evidenced by the microsatellite instability phenotype, or mutations in the K-ras and/or beta-catenin genes, are recognized major alterations, which define the progression of the normal endometrium to hyperplasia, to endometrial intraepithelial neoplasia, and then on to carcinoma. In contrast, Type II cancers show mutations of TP53 and Her-2/neu and seem to arise from a background of atrophic endometrium. Nevertheless, despite the great effort made to establish a molecularly-based histological classification, the following issues must still be clarified: what triggers the tumor cells to invade the myometrium and what causes vascular or lymphatic dissemination, finally culminating in metastasis? RUNX1, a transcription factor, was recently identified as one of the most highly over-expressed genes in a microarray study of invasive endometrial carcinoma. Another candidate gene, which may be associated with an initial switch to myometrial infiltration, is the transcription factor ETV5/ERM. These studies, as well as those conducted for other genes possibly involved in the mitotic checkpoint as a major mechanism of carcinogenesis in non-endometrioid endometrial cancer, could help in understanding the differences in the biology and the clinical outcome among histological types.

Expression of androgen, oestrogen alpha and beta, and progesterone receptors in the canine prostate: differences between normal, inflamed, hyperplastic and neoplastic glands.

The expression of receptor for androgen (AR), oestrogen alpha and beta (ERalpha and ERbeta) and progesterone (PR) was examined immunohistochemically in canine prostate specimens (normal, hyperplastic, inflamed [prostatitis] or neoplastic). AR immunolabelling was seen in 100% of epithelial cells of normal and hyperplastic tissue, the corresponding figures for inflamed and carcinomatous tissue being 74% and 65%, respectively. ERalpha labelling was seen in 85% of epithelial cells in normal prostate glands, the corresponding figures for hyperplastic, inflamed and neoplastic glands being 35%, 22% and 12%, respectively. ERbeta labelling was seen in 85% of epithelial cells of normal glands and in about 70% of such cells in glands showing pathological changes. On the other hand, PR expression (weak) in normal glands was observed in fewer epithelial cells (44%) than in hyperplastic (70%), inflamed (62%) or neoplastic (64%) glands.

Molecular determinants of invasion in endometrial cancer.

Endometrial carcinoma is the most common gynaecological malignancy in the western world and the most frequent among infiltrating tumours of the female genital tract. Despite the characterisation of molecular events associated with the development of endometrial carcinoma, those associated with the early steps of infiltration and invasion in endometrial cancer are less known. Deep myometrial invasion correlates with more undifferentiated tumours, lymph-vascular invasion, node affectation and decreased global survival. In this review we present an overview of the molecular pathology of myometrial infiltration that defines the initial steps of invasion in endometrial cancer. Down-regulation of E-cadherin as a main player of epithelial to mesenchymal transition, as well as modifications on other molecules involved in cell-cell contacts, render cells with a migratory phenotype. In addition, altered signalling pathways and transcription factors associate with myometrial invasion, histologic grade and metastasis.

Improved surgical mesh integration into the rat abdominal wall with arginine administration.

Prosthetic meshes are used as the standard of care in abdominal wall hernia repair. However, hernia recurrences and side effects remain unsolved problems. The demand by health care providers for increasingly efficient and cost-effective surgery encourages the development of newer strategies to improve devices and outcomes. Here, we evaluated whether l-arginine administration was able to ameliorate long-term polypropylene prostheses incorporation into the abdominal wall of Sprague-Dawley rats. Meshes were placed on-lay and continuous l-arginine was administered. In vivo biocompatibility was studied at 7, 25 and 30 days post-implantation. Effectively, l-arginine administration in combination with mesh triggered subtle changes in ECM composition that impinged on critical biochemical and structural features. Lastly, tensile strength augmented and stiffness decreased over the control condition. This could help to restructure the mechanical load transfer from the implant to the brittle surrounding tissues, i.e., impact load and fatigue load associated with mechanical tensions could be distributed between the mesh and the restored tissue in a more balanced manner, and ultimately help to reduce the incidence of loosening, recurrences, and local wound complications. Since the newly formed tissue is more mechanically stable, this approach could eventually be introduced to human hernia repair.

Frameshift mutations at mononucleotide repeats in caspase-5 and other target genes in endometrial and gastrointestinal cancer of the microsatellite mutator phenotype.

The majority of tumors from hereditary nonpolyposis colorectal cancer families and a subset of unselected gastrointestinal and endometrial tumors exhibit a microsatellite mutator phenotype (MMP) that leads to the accumulation of hundreds of thousands of clonal mutations in simple repeat sequences. The mutated genes with positive or negative roles in cell growth or survival in aneuploid gastrointestinal cancer (e.g., APC, K-ras, and p53) are less frequently mutated in near-diploid MMP gastrointestinal tumors. These tumors accumulate mutations in other genes, such as DNA mismatch repair hMSH3 and hMSH6, transforming growth factor-beta type II receptor, and BAX. All these genes carry, within their coding sequences, mononucleotide repeats that are preferred targets for the MMP. Endometrial carcinoma is the most common type of extracolonic neoplasia in the hereditary nonpolyposis colorectal cancer syndrome, but the spectrum of its target cancer genes is not well characterized. Here, we report that endometrial cancer of the MMP also accumulates mutations in genes that are typically mutated in gastrointestinal cancer of the mutator pathway, including BAX (55%), hMSH3 (28%), and hMSH6 (17%). We also report the detection of frameshift mutations in caspase-5, a member of the caspase family of proteases that has an (A)10 repeat within its coding region, in MMP tumors of the endometrium, colon, and stomach (28, 62, and 44%, respectively). We therefore suggest caspase-5 as a new target gene in the microsatellite mutator pathway for cancer.

PTOV1, a novel protein overexpressed in prostate cancer containing a new class of protein homology blocks.

In a search for molecular markers of progression in prostate cancer by means of differential display, we have identified a new gene, which we have designated PTOV1. Semiquantitative RT-PCR has established that nine out of 11 tumors overexpress PTOV1 at levels significantly higher than benign prostatic hyperplasia or normal prostate tissue. The human PTOV1 protein consists almost entirely of two repeated blocks of homology of 151 and 147 amino acids, joined by a short linker peptide, and is encoded by a 12-exon gene localized in chromosome 19q13.3. A Drosophila melanogaster PTOV1 homolog also contains two tandemly arranged PTOV blocks. A second gene, PTOV2, was identified in humans and Drosophila, coding for proteins with a single PTOV homology block and unrelated amino- and carboxyl-terminal extensions. A 1.8-Kb PTOV1 transcript was detected abundantly in normal human brain, heart, skeletal muscle, kidney and liver, and at low levels in normal prostate. Immunocytochemical analysis and expression of chimeric GFP-PTOV1 proteins in cultured cells showed a predominantly perinuclear localization of PTOV1. In normal prostate tissue and in prostate adenomas, PTOV1 was undetectable or expressed at low levels, whereas nine out of 11 prostate adenocarcinomas showed a strong immunoreactivity, with a focal distribution in areas of carcinoma and prostatic intraepithelial neoplasia. Therefore, PTOV1 is a previously unknown gene, overexpressed in early and late stages of prostate cancer. The PTOV homology block represents a new class of conserved sequence blocks present in human, rodent and fly proteins.

Behavior of free testosterone in patients with prostate cancer on androgen deprivation therapy.

OBJECTIVES: Determination of free testosterone (FT) serum level is an efficient method to evaluate bioavailable testosterone. We analyzed the behavior of serum FT in patients with prostate cancer receiving androgen deprivation therapy (ADT) and correlated FT with total testosterone (TT). We also analyzed the efficiency of both isoforms in the evaluation of the ADT. METHODS: Serum levels of TT and FT were determined in 191 patients with prostate cancer in a cross-sectional study. A subset of 56 patients submitted only to radical prostatectomy served as control group. The remaining 135 patients with advanced prostate cancer on three-month LHRH agonist treatment comprised the study group. The median age of the population was 73 years (range, 53-86 years) and the median time on ADT was 42 months (6-198). RESULTS: A significant correlation and linear regression between TT and FT was observed (r2 0.948). The efficiency of TT and FT to discriminate patients with and without ADT was similar (AUC: 0.993 and 0.995, respectively, p > 0.05). A castration level of serum FT established at 1.7 pg/mL had a sensitivity of 85.9% and a specificity of 100%, which are similar to the sensitivity and specificity of 50 ng/dL of TT. All patients without ADT had levels of serum TT and FT above the castration level. In 19 of the 135 (14.1%) patients on ADT serum TT was above 50 ng/dL. In 12 of these 19 patients (63.2%) serum FT was below 1.7 pg/mL while in seven patients (5.2%) FT was also above the castration level. CONCLUSIONS: The castration level of FT was established at 1.7 pg/mL. Serum TT and TF correlated very well; however, they seemed to provide complementary information in the evaluation of ADT efficiency. 14.1% of the patients on ADT failed to reach the castration level of serum TT; determination of serum FT in these patients would reduce this rate to 5.2%.

Usefulness of prostate-specific antigen nadir as predictor of androgen-independent progression of metastatic prostate cancer.

The objective of this study was to analyze the value of the nadir level of prostate-specific antigen (PSA) to predict androgen-independent progression (AIP) in metastatic prostate cancer patients after androgen deprivation therapy. In a group of 185 metastatic prostate cancer patients who received androgen deprivation therapy serum PSA was determined every three months until AIP occurred. Multiple regression analysis was performed to define independent clinical and PSA-related predictors of AIP. AIP was assumed to be present after two consecutive increases in serum PSA after the PSA nadir. Independent predictors of the duration of AIP-free survival (less than 12 months versus more than 12 months) were the extent of bone involvement (six or fewer hot spots versus more than six) with an odds ratio (O.R.) of 3.95, Gleason score (7 or less versus more than 7) with an O.R. of 3.47, and PSA nadir (2 microg/L or less versus more than 2 microg/L) with an O.R. of 14.63. AIP was independently predicted by the extent of bone involvement with an O.R. of 1.72, Gleason score with an O.R. of 1.74, PSA nadir with an O.R. of 3.22, and time to reach the PSA nadir (9 months or less versus more than 9 months) with an O.R. of 2.84. When patients were stratified according to these predictors, those with three good prognostic factors had a median AIP-free survival of 58 months while those with two, one or no good prognostic factors had a median AIP-free survival of 19 months, 12 months and 7 months, respectively. We conclude that the PSA nadir seems to be a good predictor of AIP in patients with metastatic prostate cancer after androgen deprivation therapy. Time to PSA nadir, extent of bone involvement and Gleason score are also independent predictors. The combination of these prognostic factors allows to stratify metastatic prostate cancer patients for the prediction of AIP.

Expression of the rat arginine vasopressin gene in transgenic mice.

A line of mice has been developed which are transgenic for an 8.2-kilobase (kb) genomic clone of the rat vasopressin (VP) gene. Using a polymerase chain reaction technique, the rat VP (rVP) transgene was shown to have tissue-specific mRNA expression in the hypothalamus, temporal lobe, parietal cerebral cortex, cerebellum, and posterior pituitary, similar to the tissue distribution of endogenous mouse and rat VP expression. Expression of transgenic rVP mRNA was also found in the lung and pancreas of the transgenic mice, sites of known ectopic expression of VP. Using two methods, Northern blot analysis with species-specific cRNA probes and a quantitative polymerase chain reaction technique, the quantity of rVP transgene mRNA was shown to regulate appropriately in response to an osmotic stimulus. After 72 h of water deprivation, the quantity of transgenic rVP mRNA increased 6.8 +/- 3.0-fold. This was not significantly different than the fold increase in mouse VP mRNA quantity seen in nontransgenic mice (4.8 +/- 1.5) but was significantly different (P < 0.05) than the 1.2 +/- 0.03-fold increase in rat VP mRNA seen in normal rats after water deprivation. In the rat hypothalamus, VP mRNA poly(A) tail length increases with osmotic stimulation, while in the mouse it does not. The poly(A) tail of transgenic rVP mRNA expressed in mouse hypothalamus did not increase in length after osmotic stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Hormonal regulation of rat androgen-binding protein (ABP) messenger ribonucleic acid and homology of human testosterone-estradiol-binding globulin and ABP complementary deoxyribonucleic acids.

Complementary DNA clones coding for rat androgen-binding protein (rABP) were isolated from a rat testis cDNA library constructed in the bacteriophage lambda gt11. The library was screened immunochemically, using two different antibodies against rABP. The identity of the isolated clones was confirmed by epitope selection and DNA sequence analysis. The mRNA encoding rABP could be detected in the testes of 20- and 46-day-old-rats, but not in the 10-day-old rats by hybridization with 32P-labeled rABP cDNA in a Northern blot of poly(A)+-RNA fractioned by agarose gel electrophoresis. No hybridization signal was seen with poly(A)+-RNA isolated from kidney and liver. The rABP mRNA appeared as a single species with a size of 1.65 kilobase, sufficient to encode a protein of 42,000 daltons. The concentration of rABP mRNA in the testes of 37-day-old hypophysectomized rats increased after treatment with testosterone and FSH, given alone or in combination. Sequence and hybridization analysis of cDNAs for rABP, human testosterone-estradiol-binding globulin, and human ABP demonstrates that the cDNAs for human testosterone-estradiol binding globulin and human ABP have greater sequence similarity with each other than either has with rABP.

Simultaneous treatment with statins and aspirin reduces the risk of prostate cancer detection and tumorigenic properties in prostate cancer cell lines.

Nowadays prostate cancer is the most common solid tumor in men from industrialized countries and the second leading cause of death. At the ages when PCa is usually diagnosed, mortality related to cardiovascular morbidity is high; therefore, men at risk for PCa frequently receive chronic lipid-lowering and antiplatelet treatment. The aim of this study was to analyze how chronic treatment with statins, aspirin, and their combination influenced the risk of PCa detection. The tumorigenic properties of these treatments were evaluated by proliferation, colony formation, invasion, and migration assays using different PCa cell lines, in order to assess how these treatments act at molecular level. The results showed that a combination of statins and aspirin enhances the effect of individual treatments and seems to reduce the risk of PCa detection (OR: 0.616 (95% CI: 0.467-0.812), P<0.001). However, if treatments are maintained, aspirin (OR: 1.835 (95% CI: 1.068-3.155), P=0.028) or the combination of both drugs (OR: 3.059 (95% CI: 1.894-4.939), P<0.001) represents an increased risk of HGPCa. As observed at clinical level, these beneficial effects in vitro are enhanced when both treatments are administered simultaneously, suggesting that chronic, concomitant treatment with statins and aspirin has a protective effect on PCa incidence.

Steroidogenesis of cultured purified pig Leydig cells: effects of lipoproteins and human chorionic gonadotropin.

Dispersed Leydig cells were prepared from pig testes and purified in a discontinuous Percoll gradient. About 95% of these cells stained for 3 beta-hydroxysteroid dehydrogenase. The cells were cultured in a chemically defined medium. Testosterone production was low (2 +/- 0.4 ng/10(6) cells/day) under basal conditions, but increased by 8- to 10-fold on the third day of daily human CG (hCG) treatment. Addition to the medium of both human and pig low density lipoprotein (LDL) produced a dramatic increase in both basal (8-fold) and acute hCG-stimulated (5-fold) testosterone production, whereas both human and pig high density lipoprotein were far less effective. Furthermore the effect of lipoproteins was synergistic with that of hCG. The effects of human LDL on both basal and hCG-stimulated testosterone productions were dose-dependent. Maximum effect was achieved at a protein concentration of 10-40 micrograms/ml with an ED50 of about 4 micrograms/ml. Three days of pretreatment with hCG or (Bu)2cAMP alone induced Leydig cell steroidogenic refractoriness to both hCG and (Bu)2cAMP stimulation. Concomitant treatment with LDL restored the steroidogenic capacity, but only partially. Production of pregnenolone and testosterone of desensitized cells was significantly higher than that of control cells under basal conditions, but was 60% and 40% lower, respectively, after acute hCG stimulation. Moreover, the conversion of exogenous pregnenolone to testosterone by desensitized cells was only 60% of that of control cells. These results show that the de novo synthesis of cholesterol is able to account for only 25% of the maximal steroidogenic capacity of pig Leydig cells and that hCG-induced steroidogenic desensitization is only partially due to cholesterol depletion.

Meiotic arrest and germ cell apoptosis in androgen-binding protein transgenic mice.

The fundamental role of androgen-binding protein (ABP) in spermatogenesis remains obscure after nearly 25 yr since its first characterization. In the present investigation, we used a transgenic mouse model that overexpresses rat ABP to examine the potential involvement of this protein in the regulation of processes occurring during spermatogenesis. Specifically, homozygous or heterozygous transgenic mice were analyzed in terms of spermatogenic progression, DNA fragmentation pattern, and germinal cell ploidy status. All animals homozygous for transgenic ABP exhibited an increased accumulation of primary spermatocytes and cells at metaphase with abnormal morphology and localization within the seminiferous epithelium. Analysis of DNA fragmentation by in situ techniques and agarose gel electrophoresis provided evidence for an increased occurrence of apoptosis in the transgenic animals, principally involving pachytene spermatocytes and cells at metaphase. Flow cytometric analysis of the DNA content of isolated germ cells revealed a reduction in the number of haploid cells, an increase in the number of tetraploid cells, and the appearance of a hypotetraploid cell population, consistent with degenerating primary spermatocytes. In mice heterozygous for the transgene, the effects were less prominent, and the degree to which spermatogenesis was compromised correlated with the levels of ABP messenger RNA in individual animals. The present results are interpreted to suggest that ABP can act as a modulator of spermatogenesis by regulating completion of the first meiotic division of primary spermatocytes.

Transgenic mouse models of vasopressin expression.

Arginine vasopressin is a nine-amino acid neuropeptide hormone important in the regulation of water metabolism. It also may have a role in other physiological functions, such as blood pressure regulation and the response to stress. Whole animal studies have provided a good understanding of vasopressin physiology and regulation of the normal vasopressin gene, and in vitro cell culture studies have demonstrated important features of the intracellular regulation of vasopressin gene expression. Transgenic mice provide useful models for the study of the in vivo regulation of gene expression. Previously reported mouse lines transgenic with vasopressin gene constructs have not expressed the transgene in a tissue distribution similar to that detected for the endogenous mouse vasopressin gene. An 8.2-kb genomic construct of the rat vasopressin gene, including 3 kb each of 5' and 3' flanking sequences, has been used to develop a line of transgenic mice. These animals express the transgene in a tissue-specific manner, demonstrate appropriate osmotic regulation of transgenic vasopressin mRNA, and have normal water metabolism. Animals homozygous for the 8.2-kb transgene have increased basal plasma levels of vasopressin peptide but have no apparent change in basal water metabolism. The findings with this and other previously reported mouse lines transgenic for vasopressin constructs provide a basis for developing future transgenic lines to study the in vivo regulation of the vasopressin gene.

The clinicopathological significance of K-RAS point mutation and gene amplification in endometrial cancer.

The aim of this study was to examine the prevalence and clinicopathological significance of K-RAS oncogene activation in endometrial carcinoma and atypical hyperplasia. We analysed K-RAS point mutation and gene amplification in 55 endometrial carcinomas using polymerase chain reaction associated with restriction fragment length polymorphism and genomic differential polymerase chain reaction. Point mutations at codon 12 of K-RAS oncogene were identified in 8 of 55 (14.5%) tumour specimens. In addition, we were unable to detect any K-RAS gene amplification in any of the endometrial carcinomas studied. No correlation was found between K-RAS gene mutation and age at onset, histological subtype, grade of differentiation, clinical stage or current patient status. We conclude that K-RAS mutation is a relatively common event in endometrial carcinomas, but with no clear prognostic value.

Tissue-specific expression of the rat androgen-binding protein/sex hormone-binding globulin gene in transgenic mice.

The testicular Sertoli cell produces an extracellular androgen-binding protein (ABP) that binds testosterone and dihydrotestosterone with high affinity. The ABP gene also encodes plasma sex hormone-binding globulin (SHBG), which is produced by the liver of most species. Unlike the human, adult rats and mice do not express SHBG. A 5.5-kb rat genomic DNA fragment was found to contain the entire coding regions of ABP and 1.5 kb upstream of the transcription start site. To aid in identification of the promoter and enhancer regions of the ABP/SHBG gene, we developed transgenic mice that express the rat gene. The 5.5-kb DNA was microinjected into the pronuclei of fertilized mice ova, which were transferred to the reproductive tract of pseudopregnant females. Three of the offspring were identified as carriers of the rat gene by Southern hybridization and these founders were bred with normal mice to establish heterozygous transgenic lines. Northern blot analysis, RNA-PCR and sequencing of the PCR products from the adult transgenic mice revealed extremely high levels of the rat ABP mRNA in the testis, but no detectable rat ABP mRNA in liver, kidney or brain. Primer extension experiments showed that the correct transcript ion start site is utilized in the transgenes. These data demonstrate that the 5.5-kb genomic DNA fragment contains an element(s) capable of directing ABP gene expression in the testis. This enhancer should prove useful for the targeting of specific gene products to the mature Sertoli cell in transgenic animals.

Sertoli cell-specific expression of rat androgen-binding protein in transgenic mice: effects on somatic cell lineages.

The Sertoli cells of many species produce an androgen binding protein (ABP) which carries testicular androgens to the epididymis and is thought to play a role in sperm maturation. In the present report we analyzed the morphological modifications present in Leydig, Sertoli, and peritubular cells of the testis of young adult male mice transgenic for ABP gene, which overproduce ABP in testis. By in situ hybridization we demonstrated that ABP is specifically produced by Sertoli cells. Using light and electron microscopy, we detected scattered alterations of the seminiferous tubule cells which include cell degeneration and vacuolization. Leydig and Sertoli cells present morphological signs of hyperfunctioning compensatory mechanisms which include increased amounts of lipid droplets probably due to the existence of a stimulated steroid synthesis that in turn could be a consequence of the decreased unbound testosterone and/or a direct paracrine effect of ABP. Peritubular cells also present numerous signs of hyperstimulation.

Gains of the relative genomic content of erbB-1 and erbB-2 in prostate carcinoma and their association with metastasis.

Prostate carcinoma (PC) is the second leading cause of cancer death in men in the western world. Although the role of oncogenes and growth factors in prostate carcinoma is still unclear, overexpression of the epidermal growth factor receptor (erbB-1) and the proto-oncogene erbB-2 have been reported in prostate tumors, and erbB-2 related to poor prognosis and distant metastasis. Recent allelotyping studies in prostate cancer have shown chromosomal gains in 7p and 17q, regions where erbB-1 and erbB-2 are localized respectively, although no direct evidence of an increased gene copy number of either erbB-1 or erbB-2 has been reported. To address this question, we analyzed 20 benign prostatic hyperplasia (BPH) samples and 36 samples of metastatic and non-metastatic PC by means of semiquantitative PCR. Thus, 64% (11/17) and 52% (10/19) of metastatic and non-metastatic tumors respectively showed gains of the relative genomic content of erbB-1 and an association of erbB-1 with prostate cancer but not with metastasis. Additionally, 41% (7/17) of metastatic samples showed gains of erbB-2 genomic content, suggesting an association of erbB-2 with metastasis and poor prognosis (p<0.005). No gains of erbB-1 or erbB-2 genomic content were detected in the BPH samples.