Endometrial stromal cells regulate epithelial cell growth in vitro: a new co-culture model

The regulation of epithelial cell function and morphogenesis by the paracrine effectors from the mesenchyme or stroma has been well established using in-vivo studies. A more complete understanding of these relationships has been delayed due, in part, to a lack of appropriate co-culture models. In this study, we describe a co-culture model which demonstrates that normal paracrine relationships can be reconstituted in vitro and that human endometrial stromal cells regulate both growth and differentiation of primary human endometrial epithelial cells. Interesting differences in the proliferation of stromal and epithelial cells were noted in response to the basement membrane extract, Matrigel((R)). Exposure of stromal cells to Matrigel((R)) enhanced the paracrine capacity of these cells in vitro. When epithelial cells were co-cultured in contact with stromal cells embedded in Matrigel((R)), epithelial cell growth was inhibited by 65-80% compared to controls. Stromal cells in contact with Matrigel((R)) also regulated epithelial cell differentiation, as shown by induction of glycodelin expression. These co-culture studies show great promise as a method to investigate the cellular interactions between endometrial stromal and epithelial cells and their environment and to understand the molecular basis for the regulation of normal growth and differentiation of cells within complex tissues such as the endometrium.

Lactoferrin: a tamoxifen-responsive protein in normal and malignant human endometrial cells in culture

We investigated the possible role of the estrogen-regulated protein lactoferrin (Lf) in the response of isolated normal human endometrial epithelial cells (NHEC) and established human endometrial carcinoma (EC) cell lines to tamoxifen (TAM). Using confocal laser scanning microscopy and a monospecific antibody, Lf was localized to the cytoplasm of normal and EC cells. Antibody neutralization of secreted Lf inhibited, whereas exogenous Lf (0--100 microg/ml) enhanced, cell proliferation in both classes of cells. Treatment of NHEC with TAM inhibited cell growth via a protein kinase-C-mediated pathway, concomitant with a reduction in the staining intensity for Lf. Importantly, in EC cells, TAM greatly enhanced the staining intensity for Lf, but did not affect cell growth. We propose that stable expression of Lf protein by EC cells may impart a survival advantage to these cells, which may, in part, account for the resistance of these cells to tamoxifen.

Basement membrane induced differentiation of HEC-1B(L) endometrial adenocarcinoma cells affects both morphology and gene expression

In vitro studies of endometrial carcinogenesis have been hampered by dedifferentiation of the cells in culture. Using the endometrial carcinoma cell line HEC-1B(L), we aimed to establish and characterize culture conditions that preserve a more differentiated state of the tumor cells. HEC-1B(L) cells grown in a serum-free defined medium on plastic (PL/SFDM) on top of a reconstituted basement membrane (Matrigel, MG/SFDM) or in a thick layer of Matrigel showed pronounced morphological differentiation as compared with HEC-1B(L) cells cultured on plastic in a medium containing serum (PL/10% FCS). Features of differentiation included cuboidal to columnar cell shape and an increase of rough endoplastic reticulum in Matrigel cultures. Gene expression of HEC-1B(L) cells was studied by metabolic [35S]methionine labeling and SDS-gel electrophoresis. HEC-1B(L) cells cultured in the presence of Matrigel showed two additional secretory proteins approximately 31 kD and 77 kD in size. rt-PCR was used to screen cell cultures for the presence of estrogen receptor, progesterone receptor, and lactoferrin-mRNA, genes typically expressed by normal endometrial epithelium. We found no expression of the estrogen receptor or progesterone receptor. Lactoferrin-mRNA was present under all culture conditions tested. Our results suggest a regulatory role of the extracellular matrix for the differentiation of the HEC-1B(L) cell line.

On the relationship of matrix association and DNA replication

The nuclear matrix is believed to contain sites of assembly of protein complexes that catalyze the initiation of DNA replication as well as DNA elongation. To explore this relationship, DNA replicated by human fibroblasts at the beginning of the S phase was purified and used to construct a cosmid library. Hybridization studies with a subgroup of clones (about one-sixth of the total clones in this library) showed that many of them were highlighted by probes prepared from early replicating DNA, as well as from nuclear matrix-associated DNA. Statistical analysis showed a positive correlation between these hybridization results. We seek to identify origins of replication that are activated early in the S phase of the cell cycle in human cells. Therefore, clones isolated from this library are being analyzed for the presence of structural motifs that have been found in other origins of replication and for potential sites of attachment to the nuclear matrix. This method of analysis is illustrated here using the published sequences for the origins of replication reported for the human lamin B2 and HPRT genes.

Construction of a cosmid library of DNA replicated early in the S phase of normal human fibroblasts

We constructed a subgenomic cosmid library of DNA replicated early in the S phase of normal human diploid fibroblasts. Cells were synchronized by release from confluence arrest and incubation in the presence of aphidicolin. Bromodeoxyuridine (BrdUrd) was added to aphidicolin-containing medium to label DNA replicated as cells entered S phase. Nuclear DNA was partially digested with Sau 3AI, and hybrid density DNA was separated in CsCl gradients. The purified early-replicating DNA was cloned into sCos1 cosmid vector. Clones were transferred individually into the wells of 96 microtiter plates (9,216 potential clones). Vigorous bacterial growth was detected in 8,742 of those wells. High-density colony hybridization filters (1, 536 clones/filter) were prepared from a set of replicas of the original plates. Bacteria remaining in the wells of replica plates were combined, mixed with freezing medium, and stored at -80 degrees C. These pooled stocks were analyzed by polymerase chain reaction to determine the presence of specific sequences in the library. Hybridization of high-density filters was used to identify the clones of interest, which were retrieved from the frozen cultures in the 96-well plates. In testing the library for the presence of 14 known early-replicating genes, we found sequences at or near 5 of them: APRT, beta-actin, beta-tubulin, c-myc, and HPRT. This library is a valuable resource for the isolation and analysis of certain DNA sequences replicated at the beginning of S phase, including potential origins of bidirectional replication.

Endometrial stromal cells regulate gap-junction function in normal human endometrial epithelial cells but not in endometrial carcinoma cells

Gap junctions are transmembrane proteins comprised of six connexin subunits that facilitate direct solute transport between adjacent cells through gap junctions. Previous studies from other laboratories have documented a correlation between reduced gap-junction function and malignant transformation. In endometrial cancer, a characteristic finding is a reduction in the number of stromal cells surrounding the malignant epithelial cells. Thus, the focus of this study was to determine the effect of endometrial stromal cells on gap-junction function in normal and malignant endometrial epithelial cells. To perform these studies, we evaluated normal endometrial epithelial cells and human endometrial epithelial cells including FEEC (fetal endometrial epithelial cells immortalized with simian virus 40 large-T antigen), HEC-1A (endometrial carcinoma stage 1A), and RL-95-2 (endometrial carcinoma grade II). Gap-junctional intercellular communication (GJIC) could not be demonstrated for any of the cell lines. Low levels of GJIC were observed for normal epithelial cells and higher levels were found between stromal cells. Increased levels of GJIC were observed between the epithelial cells when they were cocultured with stromal cells. The transformed epithelial cells showed no GJIC when cultured alone or when in coculture with stromal cells. The results suggest that endometrial stromal cells may help to regulate this differentiated function of endometrial epithelial cells and that malignant endometrial epithelial cells are not responsive to these regulatory signals. Mol. Carcinog. 28:70-75, 2000.

Changes in connexin 43 protein expression in human endometrial carcinoma

The expression of connexin 43 was studied using immunohistochemical and Western blot analyses on cell lines of endometrial epithelial origin. Connexin proteins were examined because decreases in their expression and function have been correlated with carcinogenesis. The cell lines were chosen to represent increasing grades of endometrial cancer progression starting from FEEC (fetal endometrial epithelial cells; transformed with SV40 large T antigen) to HEC-1A (stage 1A endometrial carcinoma) to RL-95-2 (grade 2 endometrial carcinoma). Parallel studies using connexin 43 polyclonal antibodies for both Western blots and immunofluorescence showed that the levels of connexin 43 expression were normal endometrial stromal cells = FEEC > HEC-1A > RL-95-2. Consequently, we applied the immunofluorescence assay to analyze paraffin-embedded uterine sections from hysterectomy specimens of patients with normal endometrium and from patients diagnosed with grade 1, 2, and 3 endometrial cancer. Using five different cases from each category, we found an inverse correlation between connexin 43 expression and tumor grade. Our data indicate that connexin 43 expression may be useful as an adjunctive marker of progression for endometrial carcinoma.

Identification of chromosomal bands replicating early in the S phase of normal human fibroblasts

Normal human fibroblasts (NHF1) were released from confluence arrest (G0) and replated in medium containing bromodeoxyuridine (BrdU) and aphidicolin. Despite severe reduction in the rate of DNA synthesis by aphidicolin, cells reentering the cell cycle incorporated BrdU at regions of the human genome that replicated very early in S phase. After removal of aphidicolin and BrdU from the tissue culture medium, cells were collected in mitosis. Q-banding with 4', 6-diamidino-2-phenylindole/actinomycin D was used to identify metaphase chromosomes. A monoclonal anti-BrdU antibody and a fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse antibody were used to identify the BrdU-labeled sites. The criterion for scoring DNA replication sites was the detection of FITC fluorescence at homologous regions of both sister chromatids. Early replicating regions mapped within R-bands, but not all R-bands incorporated BrdU. Chromosomal bands 1p36.1, 8q24.1, 12q13, 15q15, 15q22, and 22q13 were labeled in 53% or more of the copies of these chromosomes in the data set, suggesting that these sites replicated very early in S phase. Chromosomal band 15q22 was the most frequently labeled site (64%), which indicates that it contains some of the earliest replicating sequences in normal human fibroblasts.

Tamoxifen alters the localization of F-actin and alpha 5/beta 1-integrin fibronectin receptors in human endometrial stromal cells and carcinoma cells

We have investigated F-actin and the integrin fibronectin receptor as possible targets of tamoxifen (TAM) signaling in a cell-based model of the endometrium. Normal human endometrial stromal cells and RL95-2 human endometrial adenocarcinoma cells were treated for 1 h with TAM, a known antagonist of protein kinase C (PKC), or with staurosporine or HA1004, two broad-spectrum protein kinase antagonists capable of inhibiting PKC and PKA, respectively. We utilized fluorescein-phalloidin and confocal microscopy to visualize the cellular distribution of F-actin. Normal stromal cells and RL95-2 cells differed in the arrangement of F-actin in control cells and in their response to TAM. In control stromal cells, actin stress fibers were well organized throughout the cell, but in RL95-2 cells, they were disorganized and present mainly at the cell periphery. F-actin in RL95-2 cells treated with TAM (0.1 and 1.0 microM) or with staurosporine (0.7 and 7.0 nM) exhibited a reorganization into stress fibers consistent with a more stationary phenotype. In contrast, TAM- or staurosporine-treated normal stromal cells exhibited an increase in the amount of organized F-actin. Interestingly, in normal stromal cells treated with staurosporine but not TAM or HA1004, these F-actin fibers appeared to terminate in dense plaques proximal to the plasma membrane. The alpha 5/beta 1 integrin fibronectin receptor mediates between the extracellular matrix and the actin cytoskeleton. TAM induced clustering of the fibronectin receptor at the plasma membrane in normal stromal cells, but not in carcinoma cells. This study supports the importance of plasma membrane-cytoskeletal protein interactions in the response of normal and carcinoma cells to TAM.

Diethylstilbestrol-induced immortalization of human endometrial cells: alterations in p53 and estrogen receptor

Carcinogenesis is a process requiring multiple steps. Immortalization is one step in this process and may be rate limiting. To further our understanding of estrogen-induced carcinogenesis, we evaluated diethylstilbestrol (DES)-induced immortalization of human endometrial stromal cells. This was achieved by assessing at the restrictive temperature the colony-forming efficiency of cells that were conditionally immortalized with a temperature-sensitive simian virus 40 large T antigen. Treatment with DES for 1 wk did not increase the immortalization frequency; however, cultures that were treated for 20 wk had a twofold increase in immortalization frequency, and continued treatment for a total of 44 wk produced a threefold increase in immortalization frequency that was dose dependent. DES-treated restrictive temperature variants (RTVs) but not spontaneous RTVs lost the temperature-sensitive phenotype. DES-RTVs also had a shorter doubling time than spontaneous RTVs did. p53 expression was increased in DES-RTVs, and its localization within the cell was altered. Conversely, expression of the estrogen receptor was decreased in DES-immortalized cells. These changes in gene expression often occur in estrogen-related malignancies, and our results are consistent with a causal role for estrogens in these p53 and the estrogen receptor alterations. Immortalization of human cells may be analogous to initiation of rodent cells, and our results suggest that estrogen-induced alterations in p53 or other genes that regulate life span could contribute to estrogen-induced initiation.

Tumor cell invasion of basement membrane in vitro is regulated by amino acids

Because most cancer deaths result from disseminated disease, understanding the regulation of tumor invasion and metastasis is a central theme in tumor cell biology. Interactions between extracellular matrices (ECM) and cellular microenvironment play a crucial role in this process. We have tested selected amino acids and polyamines for their ability to regulate RL95-2 cell invasion through both intact human amniotic basement membrane and a novel human ECM (Amgel). Three major systems for neutral amino acid transport, systems L, A, and ASC, are operational in these neoplastic cells. Amino acids entering the cell via transport system A or N, i.e., (methyl amino)-isobutyrate (MeAIB) or Asn, markedly enhanced invasiveness of these human adenocarcinoma cells as measured by a standard 72-hr amnion or Amgel invasion assay. Addition of 2-amino-2-norborane carboxylic acid (BCH; 1 mM), a model substrate of the L transport system, caused a significant decrease in invasive activity when tested in the Amgel assay. Interestingly, Val lowers steady-state levels of MeAIB uptake and blocks the increase in cell invasion elicited by MeAIB. At the same time, these amino acids do not influence cell proliferation activity. Neither the charged amino acid Lys or Asp (not transported by A/N/L systems) nor the polyamines putrescine, spermidine, or spermine modulate invasiveness under similar experimental conditions. Moreover, the observed time-dependent stimulation of system A activity (cellular influx of MeAIB) by substrate depletion is prevented by the addition of actinomycin D (5 microM) or cycloheximide (100 microM), suggesting the involvement of de novo RNA and protein synthesis events in these processes. MeAIB treatment of tumor cells selectively increased the activities of key invasion-associated type IV collagenases/gelatinases. These results indicate that in the absence of defined regulators (growth factors or hormones), certain amino acids may contribute to the epigenetic control of human tumor cell invasion and, by extension, metastasis. We propose that amino acids, acting via specific signaling pathways, modulate phenotypic cell behavior by modulating the levels of key regulatory enzymatic proteins.

The intracellular IL-1 receptor antagonist alters IL-1-inducible gene expression without blocking exogenous signaling by IL-1 beta

The epithelium-associated tissue distribution of the intracellular IL-1R antagonist (icIL-1Ra) suggests that it functions as a novel regulatory molecule for IL-1 in somatic tissues. We examined the role of the icIL-1Ra in IL-1 beta-induced responses in human ovarian cancer cells because ovarian surface epithelium expresses transcripts for the icIL-1Ra, and the majority of ovarian cancers arise from these cells. Several human ovarian and cervical cancer cell lines spontaneously express the icIL-1Ra. icIL-1Ra-expressing cells did not have altered growth characteristics or altered short term responses to IL-1 compared with icIL-1Ra-nonexpressing cells. While a 90-min exposure to IL-1 beta resulted in increased steady state cytokine mRNA levels in all cells, icIL-1Ra-positive cells were incapable of maintaining IL-1-beta-induced expression of GRO mRNA. This did not result from decreased transcriptional activity of the GRO gene, but reflected differences in mRNA stability and/or degradation. To determine whether the icIL-1Ra altered mRNA stability, we used a retroviral expression vector to express the icIL-1Ra in an icIL-1Ra-negative cell line. The resulting cells displayed a profile of IL-1 beta-induced genes analogous to that found in cells spontaneously expressing icIL-1Ra. These data show for the first time an intrinsic biologic activity for the icIL-1Ra. The capacity to selectively alter IL-1-induced gene expression suggests that this version of the IL-1Ra is a unique intracellular inhibitor that attenuates IL-1 responses at a point downstream of the initial IL-1/IL-1 receptor interaction.

The intracellular IL-1 receptor antagonist alters IL-1-inducible gene expression without blocking exogenous signaling by IL-1 beta

The epithelium-associated tissue distribution of the intracellular IL-1R antagonist (icIL-1Ra) suggests that it functions as a novel regulatory molecule for IL-1 in somatic tissues. We examined the role of the icIL-1Ra in IL-1 beta-induced responses in human ovarian cancer cells because ovarian surface epithelium expresses transcripts for the icIL-1Ra, and the majority of ovarian cancers arise from these cells. Several human ovarian and cervical cancer cell lines spontaneously express the icIL-1Ra. icIL-1Ra-expressing cells did not have altered growth characteristics or altered short term responses to IL-1 compared with icIL-1Ra-nonexpressing cells. While a 90-min exposure to IL-1 beta resulted in increased steady state cytokine mRNA levels in all cells, icIL-1Ra-positive cells were incapable of maintaining IL-1-beta-induced expression of GRO mRNA. This did not result from decreased transcriptional activity of the GRO gene, but reflected differences in mRNA stability and/or degradation. To determine whether the icIL-1Ra altered mRNA stability, we used a retroviral expression vector to express the icIL-1Ra in an icIL-1Ra-negative cell line. The resulting cells displayed a profile of IL-1 beta-induced genes analogous to that found in cells spontaneously expressing icIL-1Ra. These data show for the first time an intrinsic biologic activity for the icIL-1Ra. The capacity to selectively alter IL-1-induced gene expression suggests that this version of the IL-1Ra is a unique intracellular inhibitor that attenuates IL-1 responses at a point downstream of the initial IL-1/IL-1 receptor interaction.

Human endometrial carcinoma cells release factors which inhibit the growth of normal epithelial cells in culture

Autocrine and paracrine interactions between cells are important homeostatic mediators in normal tissues. Alterations to growth factor signalling pathways are likely to play a role in multistep carcinogenesis. In this study normal human endometrial epithelial cells (NHEC) after 3 days in culture were treated with serum-free medium conditioned for 24 h by log phase or confluent cultures of established RL95-2, HEC1A, or AN3CA endometrial carcinoma (EC) cell lines. By day 4, NHEC treated with either log phase or confluent conditioned medium (CM) showed a significant decrease (approximately 50-90% of control) in [3H]thymidine ([3H]TdR) incorporation. DNA synthesis was inhibited more by confluent than by log phase CM. By day 7, NHEC treated with CM exhibited fewer colonies per culture, fewer cells per colony, and an increased percentage of single cells. Several growth-regulatory gene products found in the nucleus or at the cell membrane have been shown to be expressed differently in normal and transformed cells. We selected the p53 and c-Ha-ras p21 proteins to further investigate the mechanism of alteration of proliferation in cells treated with carcinoma CM. Thus, by day 7, the percentage of NHEC with nuclear localization of wild type p53 (wt p53) was elevated by treatment with CM. In contrast, CM-treated EC cells continued to proliferate, and showed a decrease in the percentage of cells expressing nuclear wt p53 and an increase in the cytoplasmic expression of c-Ha-ras p21. Our studies show that EC cell lines release factors which inhibit the proliferation of NHEC, thus favoring the proliferation of EC cells.

Estrogen-induced anchorage-independence in human endometrial stromal cells

Estrogens are important etiologic agents for most gynecologic malignancies, and chronic exposure to estrogen that is unopposed by progestins conveys the greatest risk. Treatments with estrogen facilitate the process of malignant transformation in rodents, but relatively few studies of estrogen-induced carcinogenesis have been performed using human cells. Most malignancies in estrogen-responsive tissues arise from epithelial cells, but an increasing body of evidence emphasizes the role of stromal cells as mediators of the effects of estrogens on epithelial cells. Our studies were designed to assess estrogens as carcinogens for human endometrial stromal cells and to provide a basis for studies of the role of stroma in estrogen-induced carcinogenesis in humans. Acute treatments with the estrogens diethylstilbestrol (DES), 17 beta-estradiol (E2) and beta-dienestrol enhance anchorage-independent proliferation (AIP) of SV40-immortalized human endometrial stromal cells in the rank order of DES > E2 > beta-dienestrol. The anti-estrogenic compound tamoxifen inhibits DES-induced AIP. The magnitude of DES-induced AIP increases with prolonged duration of treatment. After 11 months of chronic treatment with 0.1 nM DES, AIP was 20-fold higher than in vehicle-treated control cultures. Expression of the estrogen receptor was altered by treatments with DES in parallel with increased capacity for AIP. These conditionally immortal human endometrial stromal cells appear to be a good model for estrogen-induced transformation of human cells.

Phenobarbital modulates the type of cell death by rat hepatocytes during deprivation of serum in vitro

An immortal line of chemically altered rat hepatocytes was used to study the effects of the liver tumor promoter, phenobarbital (PB), on hepatocyte growth and viability in vitro. When the serum concentration in medium was changed from 10% to 0.5%, cell proliferation decreased and hepatocytes died. Death of the hepatocytes occurred after 2 days in low-serum medium. PB appeared to control the type of cell death that occurred. In the absence of PB in low-serum medium, most dead cells had morphological changes that are characteristic of necrosis as determined by both light and electron microscopy. In the presence of PB, the dead cells had alterations typical of apoptosis. Biochemical features of cell death in low-serum medium were also analyzed. DNA isolated from cells in low serum with PB showed nucleosome-length fragments after gel electrophoresis, whereas DNA from cells in low serum without PB appeared as randomly degraded fragments. Although proliferation of hepatocytes in low-serum decreased by 75%, the appearance of apoptosis in the presence of PB was associated with increased expression of the c-myc gene. Based on these observations, we conclude that PB can modulate the type of cell death that occurs after serum deprivation in this line of immortal rat hepatocytes. PB seemed to prevent necrotic cell death in low serum, and cells died through a gene-directed pathway of apoptosis.

Derivation of phenobarbital-responsive immortal rat hepatocytes

Two lines of rat hepatocytes, designated 6/15 and 6/27, were obtained from carcinogen-treated livers by cultivation in medium containing the liver tumor promoter, phenobarbital (PB). Both lines appeared to be PB-responsive and to have an unlimited in vitro proliferative lifespan, i.e., immortality. The ability of pure 6/27 hepatocytes to form colonies from single cells was strictly dependent upon PB; it was reduced by 97 to 99% in the absence of PB. These hepatocytes were not tumorigenic. For 6/27 hepatocytes in early passages where cultures contained fibroblast contaminants and later when they were a pure culture, PB was able to enhance colony growth from single cells and facilitated population expansion by sustaining DNA synthesis and by inhibiting cell lysis. The 6/15 line displayed PB-dependent colony formation and was not tumorigenic at early passages. At later passages 6/15 hepatocytes were less dependent on PB for colony formation, and they formed hepatocellular carcinoma when transplanted into livers of syngeneic rats. The demonstration that PB sustained the proliferation and viability of hepatocytes with enhanced growth capacity and indefinite proliferative lifespan suggests that PB may be necessary for progression of these chemically initiated hepatocytes to immortal and tumorigenic lines in vitro.

Transforming growth factor-beta 1 mediates communication between human endometrial carcinoma cells and stromal cells

The role of transforming growth factor-beta 1 (TGF-beta 1) in communication between human endometrial carcinoma (EC) cells and normal endometrial stromal cells (NSC) was investigated using a cell culture model. Serum-free conditioned medium (CMe) from EC cells (RL95-2, HEC1A) inhibited the proliferation (cells per colony < 50% of control; mitotic index 25-50% of control) of NSC. In contrast, NSC-conditioned medium (CMn) stimulated the proliferation of EC cells, but inhibited the growth of NSC. The proliferation of EC cells was stimulated by the range of dilutions of CMe which inhibited the proliferation of NSC. Using confocal microscopy and a monoclonal antibody, TGF-beta 1, a known product of differentiation in the female reproductive tract, was localized to the cytoplasm of NSC and EC cells. Using a protein slot-blot chemiluminescence method, secreted TGF-beta 1 was detected in serum-free medium conditioned by the growth of NSC and EC cells. TGF-beta 1 antibody-neutralized CMe or CMn stimulated the proliferation of both NSC and EC cells. This study suggests that endometrial carcinoma-stromal cell interactions involve autocrine-paracrine signaling pathways, and that TGF-beta 1 protein is one mediator of such interactions.

Management of prostatic abscess in patients with human immunodeficiency syndrome

OBJECTIVE

To review and assess the management and evaluation of prostatic abscess in patients with the acquired immunodeficiency syndrome (human immunodeficiency virus [HIV]).

METHODS

Retrospectively reviewed 7 cases of prostatic abscess in HIV-positive patients treated at our institution.

RESULTS

All 7 patients presented with fever and irritative voiding symptoms. Only 1 patient had a positive initial urine culture; 3 of 5 operative cases only had positive intraoperative culture. Organisms cultured were Staphylococcus aureus, enterococcus. Mycobacterium tuberculosis, and Mycobacterium avium.

CONCLUSIONS

Transrectal ultrasonography is the imaging modality of choice for diagnosing this condition; it also directs the appropriate surgical approach. Transurethral unroofing should be attempted whenever significant extension outside the prostate is not found. Intraoperative cultures for aerobes, anaerobes, fungi, and mycobacteria must be obtained.

In vitro interactions of endometrial stromal and epithelial cells in Matrigel: reorganization of the extracellular matrix

Fragments of human endometrial glands and dispersed endometrial stromal cells were cultured together in a thick layer of reconstituted basement membrane (Matrigel). Epithelial cells kept their glandular morphology whereas stromal cells grew into round clusters of mainly fusiform cells. Transmission electron micrographs showed collagen fibers between stromal cells as well as in surrounding extracellular matrix after 2.5 weeks. A well-defined basement membrane was found when epithelial and stromal cells were in close proximity to each other. Beneath the lamina densa there was a loose network of collagen fibers or a dense fibrillar network arranged parallel to the cell layers. Epithelial cells showed hemidesmosomes at their basal surface where they were close to stromal cells.

Association of putative origins of replication with the nuclear matrix in normal human fibroblasts

Several metabolic processes, such as DNA organization and replication, transcription, and RNA processing are closely associated with the nuclear matrix. Nuclear matrix attachment regions are nucleotide sequences holding DNA tightly complexed with the nuclear scaffold and are resistant to extractions with detergents and high salt solutions. The role of matrix attachment regions in DNA replication has not been completely clarified, but they have been identified in close association with origins of replication in mammalian cells. We isolated nuclear matrix-associated DNA from normal human fibroblasts synchronized to different phases of the cell cycle and cloned compatible fragments into pUC19. We tested the homology of a fraction of the available clones to DNA replicated at the beginning of the S phase in human fibroblasts. We confirmed that nuclear matrix-associated DNA isolated from cells in G0 and G1 phases of the cell cycle contains sequences that are among the earliest replicated regions in the human genome. This finding supports the hypothesis that matrix attachment regions in human DNA are located in close proximity to origins of DNA replication.

Cell cycle control, DNA repair and initiation of carcinogenesis

We hypothesize that degradation of controls that normally act to inhibit cell proliferation is an early step in carcinogenesis. This alteration gives rise to initiated clones that display a selective growth advantage over normal cells when subjected to appropriate growth-promoting influences. In cell culture, such initiated cells also may display a selective growth advantage that lets them proliferate under conditions in which normal cell growth ceases. Cells with these properties have been designated enhanced-growth variants (EGVs)2 (1) or extended life span variants (ELVs) (2). We propose that the EGV/ELV phenotypes in vitro and initiation of carcinogenesis in vivo are consequences of genetic changes in pathways that regulate the passage of cells through the cell cycle. These regulatory pathways normally delay or arrest cell cycle progression in response to homeostatic regulators and DNA damage. DNA damage induced by a variety of genotoxic agents triggers delays in cycle progression at three steps of the cell cycle. Two of these involve delays in progression from G1 into S phase and G2 into mitosis. The third occurs within S phase cells and involves reduction in the rate of initiation of DNA synthesis in replicon clusters. If these cycle delay responses fail, damaged DNA may be replicated before it is adequately repaired. This would enhance production of additional genetic alterations. Thus, mutations in genes that normally exert a negative control over cell cycle progression may give cells a growth advantage and make the cells more genetically unstable.

Identification of human DNA in complex biological samples using the Alu polymerase chain reaction

Alu-Polymerase chain reaction (PCR) was used to amplify human DNA from complex mixed sources of DNA. Amplification of human DNA sequences by Alu-PCR could be accomplished in samples containing low concentrations of template in the presence of excess heterologous DNA sequences. Thus, sensitivity and specificity are maintained in complex DNA mixtures allowing positive identification of the presence of human DNA sequences by this technique.

Conditional immortalization of human endometrial stromal cells with a temperature-sensitive simian virus 40

The study of immortalization and other alterations associated with neoplastic transformation of endometrial stromal cells is important to understanding the development of uterine sarcomas and mixed tumors. Because stromal cells are important regulators of associated epithelial cells, alterations in the regulation of stromal cell proliferation that influence epithelial cells may also contribute to the development of endometrial carcinomas. To study immortalization and associated phenotypic and genetic alterations of human endometrial stromal cells, cultures were transfected with a plasmid containing an ori-, temperature-sensitive mutant SV40, A209 (tsSV40). Morphologically transformed colonies were selected and propagated at the permissive temperature until they entered 'crisis'. In contrast to human fibroblasts, every clone tested was immortalization competent. The frequency of immortalization was approximately 1 x 10(-6). One uncloned and six cloned cell lines escaped from crisis and appear to be immortal. Two clones, M4 and B10T1, were selected for further study. Immortalization is conditional; proliferative arrest occurs at the restrictive temperature for large T antigen function. Furthermore, withdrawal of the large T antigen results in expression of the senescent phenotype of enlarged, flattened cells. Colony-forming efficiency at the restrictive temperature was undetectable. Immortalization is also associated with several genetic alterations. The DNA content of tsSV40 transfected cells was either diploid or tetraploid in the precrisis stage of proliferation, but became aneuploid upon immortalization. Several structural rearrangements of chromosomes were detected in the immortalized stromal cells which differ from those found in SV40 immortalized fibroblasts. Although their capacity for anchorage-independent proliferation (AIP) is variable, tsSV40-immortalized endometrial stromal cells have a higher capacity for AIP than their tsSV40-transfected progenitor cells in the period of proliferation prior to 'crisis'.

Development of a novel human extracellular matrix for quantitation of the invasiveness of human cells

During the crucial stages of tumor cell invasion and metastasis, neoplastic cells must traverse extracellular matrices for their migration to distant sites. Because basement membranes (BM) serve as a critical barrier to such passages, most previous in vitro assay models have utilized either an intact BM or a reconstituted rodent or avian BM-matrix to study this process. We have created a gel-like extracellular matrix derived from human amnions which contained type IV collagen, laminin, entactin, tenascin and heparan sulfate proteoglycan. This matrix, which we called Amgel, was used to study selected steps of invasion including cell attachment to matrix, degradation of it by proteolytic enzymes and movement of human tumor cells through matrix defects. An efficient tumor invasion assay system was developed utilizing filter-supported uniform coatings of this matrix in chambers. Human tumor cells (HT-1080 fibrosarcoma and RL-95 adenocarcinoma), when seeded onto Amgel-coated membranes, attached to matrix within 2 h and initiated a time-dependent migration and invasion process, as verified by biochemical analysis and both light and electron microscopy. In an optimized invasion assay 12-15% of tumor cells completely traversed the matrix during a 72-h period with > 90% viability. In contrast to these highly-invasive cells, normal human foreskin fibroblasts and normal human endometrial stromal cells exhibited minimal migration/matrix penetration during the same time period. When the Amgel-selected tumor cells (i.e. those penetrating the barrier) were isolated, subcultured, and re-exposed to Amgel, they had heightened invasiveness (2-3-fold) as compared to the parental cells. Thus, this improved 'all human' system for quantitating the invasive ability of tumor cells may provide a valuable tool in dissecting out the mechanistic underpinnings of human metastasis. In addition, this assay has the ability to screen agents which have potential anti-invasive and by extension anti-metastatic, activity or chemotactic properties.

Localization of tenascin in uterine sarcomas and partially transformed endometrial stromal cells

Normal mesenchymal cells within developing embryonic organs and transformed stromal cells in organs undergoing spontaneous carcinogenesis have the capacity for normal or altered expression of the extracellular matrix glycoprotein tenascin (Tn). Mesenchymal cell constituents of normal adult organs show only a very limited tendency to deposit Tn in their extracellular matrix. In the present study, we investigated whether malignant human mesenchymal cells derived from uterine sarcomas or normal human endometrial stromal cells partially transformed via transfection with selected oncogenes have the capacity to produce and deposit Tn. We reached the following conclusions: (1) compared with normal endometrial tissues, uterine sarcomas show heterogeneous, but increased, immunoreactive staining patterns exclusively within the extracellular compartment, regardless of the histologic subtype of the tumor; (2) in vitro, all normal and transfected stromal cells and cell lines examined secreted Tn into the tissue culture medium; (3) this secretory ability was not translated into morphologic uniformity, since immunoreactivity detected by confocal laser scanning microscopy was observed in only selected cell populations; (4) also, the deposition and the incorporation of Tn depended upon the density of transfected cells, and (5) double-staining experiments revealed that Tn could always be localized in close proximity to fibronectin. In summary, the production of Tn is increased in most cases of human uterine sarcoma. The capacity of stromal cells to deposit Tn in a matrix-like structure in vitro, rather than increase production of Tn, is correlated with the degree of neoplastic progression.

Expression of tissue kallikrein in normal and SV40-transfected human endometrial stromal cells

The polymerase chain reaction with specific tissue kallikrein primers was utilized to demonstrate the presence of tissue kallikrein mRNA in human endometrial stromal cells. Enzymatic analysis measured with a specific tripeptide nitroanilide substrate demonstrated the presence of tissue kallikrein in the conditioned medium obtained from both normal stromal cells and stromal cells transfected with an origin-defective temperature-sensitive SV40 large T antigen. The transfected stromal cell supernatant exhibited approximately twice as much tissue kallikrein activity as normal stromal cells at 60-100% of cell confluence. The release of tissue kallikrein from transfected stromal cells was confirmed by Western blot analysis and [35S]-methionine incorporation into a 35-kD protein which retains tissue kallikrein activity. These results demonstrate for the first time the expression and secretion of tissue kallikrein in human endometrial stromal cells and provide evidence of possible involvement of tissue kallikrein in cell transformation.

Differential effects of dioctanoylglycerol on fibronectin localization in normal, partially transformed, and malignant human endometrial stromal cells

In this study, we describe the effects of direct activation of PKC by dioctanoylglycerol (DiC8) on cellular morphology and the localization of fibronectin (Fn) in normal, oncogene-transfected, and malignant human endometrial stromal cells. We questioned whether DiC8, an endogenous specific activator of PKC, would function as a second oncogene in partially transformed human endometrial stromal cells (HESC). Cells utilized were (1) normal HESC, (2) HESC transfected with a plasmid containing an origin-defective temperature-sensitive SV40 large T antigen alone or (3) in combination with an EJ ras oncogene, and (4) an endometrial sarcoma cell line (S7). Cell cultures were treated for 1 h with sn-dioctanoylglycerol (DiC8) and stained with a monoclonal fluorescein-labeled anti-Fn antibody. In normal HESC, DiC8 induced cell rounding and caused Fn localization to revert from the perinuclear region to the cell periphery. All experiments in this investigation were performed when cells were maintained at the permissive temperature for SV40 large T antigen function. In HESC expressing the SV40 large T antigen alone, Fn was localized to the perinuclear region and also occurred as parallel strands between cells. When these cells were treated with DiC8, Fn localization changed to intense punctate regions at the cell periphery or to matrix-like patterns between cells. Also, in these cells, DiC8 induced greater detachment of cells from the substrate than from other cells, resulting in an apparent piling up of cells. Control and treated SV40/EJ ras cells and uterine sarcoma cells expressed Fn in a matrix-like pattern between cells. The rounded cellular morphology of treated HESC and treated cells expressing SV40 resembled the morphology of control or treated SV40/EJ ras cells and uterine sarcoma cells. Thus, treated cells expressing the SV40 large T antigen resembled the SV40/EJ ras cells and uterine sarcoma cells with respect to Fn localization and cellular morphology. DiC8 did not appear to further transform HESC expressing SV40 and EJ ras. However, with regard to cell shape and Fn localization, our results suggest that DiC8 may function as a second oncogene in the signal transduction pathway, in cells expressing SV40 alone. It appears that, with regard to Fn localization, DiC8 may alter signal transduction analogously to that caused by the activated Ha-ras oncogene in HESC expressing the SV40 large T antigen.

Association between expression of transforming growth factor-alpha and progression of hepatocellular foci to neoplasms

Hepatocarcinogenesis was initiated in rats with a single dose of either of two chemical mutagens--benzo[a]pyrene diolepoxide I and methyl(acetoxymethyl)nitrosamine--administered 15 h after partial hepatectomy. The development of hepatocellular foci and neoplasms was then promoted with dietary phenobarbital given for 45 or 62 weeks. Formalin-fixed tissue specimens that contained hepatic neoplasms and altered hepatocellular foci were screened for expression of the oncodevelopmental marker glutathione-S-transferase (placental form) (GSTP) and transforming growth factor-alpha (TGF-alpha) using immunohistochemistry. All (100%) hepatocellular carcinomas expressed both GSTP and TGF-alpha, as did most hepatocellular adenomas (greater than 80%). However, quantitative stereologic analysis of treated and control livers revealed that GSTP-positive foci were 10-30 times more frequent than TGF-alpha-positive foci. Foci with homogeneous expression of GSTP generally displayed heterogeneous expression of TGF-alpha with reaction product most prominent at their peripheries. Less frequently homogeneous TGF-alpha-positive foci were seen within GSTP-positive foci. The average volumes of those GSTP-positive foci that also expressed TGF-alpha were significantly greater than those of the entire sets of GSTP-positive foci. These results suggest that expression of TGF-alpha may distinguish a subset of GSTP-positive foci that have a growth advantage and increased probability of progression to neoplasia.

Partial characterization of nuclear matrix attachment regions from human fibroblast DNA using Alu-polymerase chain reaction

The proteinaceous nuclear matrix of mammalian cell nuclei has been suggested to be involved in the regulation of chromatin structure, DNA replication, and gene expression. Interaction between cellular DNA and the nuclear matrix is mediated by putative DNA binding sequences, matrix attachment regions (MARs), which may become altered during early events in cellular transformation. Among the cellular changes occurring during the development of neoplasia, all of which may potentially involve the nuclear matrix, are alterations in nuclear structure, loss of control of DNA replication, and significant modifications of cellular gene expression. Therefore, a better understanding of the interaction between DNA and the nuclear matrix is needed. Isolated matrix associated DNA from pulse labeled SV40 transformed human fibroblasts was shown to be enriched in newly replicated DNA, confirming the association of DNA replication with the nuclear matrix as observed by others. Subgenomic fractions of matrix associated DNA enriched in putative MARs sites were prepared from quiescent and logarithmically growing normal human fibroblasts and SV40 transformed human fibroblasts. These fractions of DNA were analyzed by Alu-polymerase chain reaction and agarose gel electrophoresis, revealing complex and unique patterns of DNA products for each cell type investigated. A number of prominent DNA fragments with similar molecular size were found to be present in the amplified DNA products of each DNA source, suggesting that these DNA fragments may represent common DNA sequences which contain MARs sites or which are associated with MARs sites. The application of Alu-polymerase chain reaction to the molecular analysis of nuclear matrix associated DNA may facilitate the isolation and characterization of potentially new human MARs sequences.

Initiation by bleomycin of hepatocellular foci in the rat

The antitumor antibiotic, bleomycin, was tested for activity as an initiator of hepatocellular foci and neoplasms in rats. The compound was administered in a single dose via the portal vein 4 h after the proliferative stimulus of a two-thirds partial hepatectomy. Rats were subsequently fed diet containing phenobarbital for up to 41 weeks to promote the development of initiated hepatocytes. Bleomycin-treated livers displayed significantly increased frequencies of basophilic hepatocellular foci and hepatocellular foci which retain glycogen during fasting. Foci that express glutathione-S-transferase (placental form) were not initiated by bleomycin. Hepatocellular neoplasms were infrequently seen in bleomycin-treated livers (5% incidence). The results suggest that oxygen radical-mediated DNA damage may initiate, within populations of proliferating hepatocytes, new lineages of altered hepatocytes that form foci but have low probability of progressing to neoplasms during promotion with phenobarbital.

Effects of the SV40 large T antigen and EJ ras oncogene on fibronectin localization in human endometrial cells as viewed by confocal laser scanning microscopy

We utilized confocal laser scanning microscopy to examine the localization of fibronectin deposition in cultures of human endometrial stromal cells. We found that fibronectin in normal human endometrial stromal cell cultures was both intracellular, occurring in rough endoplasmic reticulum and in perinuclear regions, and extracellular, occurring diffusely over the entire cell surface. Endometrial stromal cells were transfected with a plasmid containing an origin-defective Simian Virus 40 (SV40) which codes for a temperature-sensitive large T antigen. When these cells were placed under temperature-restrictive conditions for large T-antigen function, they exhibited staining patterns similar to normal endometrial cells. Fibronectin deposition in cultures of partially or fully transformed endometrial cells was not intracellular as in normal cells, but was localized primarily between cells. Cells expressing the SV40 large T antigen deposited fibronectin mainly in parallel clumps between cells. Cells expressing both the SV40 large T antigen and the EJ ras oncogene, at high cell density, displayed networks of fibronectin arranged in matrix-like patterns between cells. The malignant cell line examined, sarcoma cells, also exhibited fibronectin networks between cells. Cell density affected fibronectin deposition in endometrial stromal cells expressing the EJ ras oncogene. At low density, cells expressing the SV40 large T antigen and the EJ ras oncogene displayed diffuse fibronectin patterns and, at high density, these cells formed colonies with networks of fibronectin between cells.

Alterations of DNA content in human endometrial stromal cells transfected with a temperature-sensitive SV40: tetraploidization and physiological consequences

The normal genomic stability of human cells is reversed during neoplastic transformation. The SV40 large T antigen alters the DNA content in human endometrial stromal cells in a manner that relates to neoplastic progression. Human endometrial stromal cells were transfected with a plasmid containing the A209 temperature-sensitive mutant of SV40 (tsSV40), which is also defective in the viral origin of replication. Ninety-seven clonal transfectants from seven different primary cell strains were isolated. Initial analysis revealed that 20% of the clonal populations (19/97) had an apparent diploid DNA content, 35% (34/97) had an apparent tetraploid DNA content, and the remainder were mixed populations of diploid and tetraploid cells. No aneuploid populations were observed. Diploid tsSV40 transformed cells always give rise to a population of cells with a tetraploid DNA content when continuously cultured at the permissive temperature. The doubling of DNA content can be vastly accelerated by the sudden reintroduction of large T antigen activity following a shift from non-permissive to permissive temperature. Tetraploid tsSV40 transfected cells have a lower capacity for anchorage-independent growth and earlier entry into 'crisis' than diploid cells. These results indicate that during the pre-crisis, extended lifespan phase of growth, the SV40 large T antigen causes a doubling of DNA content. This apparent doubling of DNA content does not confer growth advantage during the extended lifespan that precedes 'crisis'.

Proliferation of carcinogen-damaged hepatocytes during cell-cycle-dependent initiation of hepatocarcinogenesis in the rat

Hepatocyte proliferation and damage to DNA were characterized during the initiation phase of carcinogenesis in livers of rats that had received a single administration of the methylating agent methyl(acetoxymethyl)nitrosamine (DMN-OAc). Quiescent non-proliferating hepatocytes in intact livers did not appear to be susceptible to initiation by DMN-OAc, whereas proliferating hepatocytes in the S phase appeared to have greatest risk. To characterize the phenomenology of S-phase-dependent initiation further, the fractions of hepatocytes in the S and M phases of the cell cycle were enumerated at various times after treatment with DMN-OAc. Hepatocytes treated when in G1 experienced a delay of up to 20 h in the onset of S phase and a reduced rate of entry into the S and M cycle phases. Hepatocytes treated when in S phase experienced considerable delay in progression to mitosis due to part to inhibition of DNA replication. Hepatocytes treated when in late S/G2 also demonstrated a delay in progression into mitosis. The levels of 7-methylguanine and O6-methyldeoxyguanosine were quantified in the nuclear DNA of proliferating hepatocytes. The kinetics of removal of these lesions appeared to be first-order (half-life = 24 h). Hepatocyte risk of initiation was modeled by a function which summed over time the product of the fraction of hepatocytes in the S phase and the fraction of residual, unrepaired damage to DNA. For hepatocytes treated when in early G1, the time-weighted frequency of premutagenic DNA damage that was present during DNA replication was estimated to be less than half of that for hepatocytes treated when in early S. The results suggest that cell-cycle-dependent variation in sensitivity to initiation of hepatocarcinogenesis may be, in part, due to efficient removal of potentially carcinogenic lesions from DNA during an extended G1. The apparent high sensitivity of hepatocytes in late S/G2 suggests the contribution of additional factors.

Automated image-based cytometry with fluorescence-stained specimens

The combination of digitized microscopy, algorithms for object recognition and fluorescent labeling is a promising approach for reliable, quick, automated and cost-effective screening of clinical specimens. We describe two conceptually different algorithms for detecting objects in fluorescence microscopic images. One, which is partially automated, compares a mask that represents a typical object with every position in the image; the other, which is fully automated, calculates threshold intensities to segment the image into regions of objects and background. Applications of the algorithms in conjunction with a prototype image-based cytometer are demonstrated for determining the DNA ploidy distribution of cultured human endometrial cells and determining the DNA ploidy distribution and the fraction of cells expressing the E6 antigen of human papilloma virus serotypes 16 and 18 in a PAP smear. The encouraging results from this study suggest that automated image-based cytometry utilizing fluorescent stains will be a valuable asset for clinical screening.

Extended life span of human endometrial stromal cells transfected with cloned origin-defective, temperature-sensitive simian virus 40

Human endometrial stromal cells transfected with an origin-defective, temperature-sensitive simian virus 40 recombinant plasmid are dependent on T-antigen function for proliferation and at the permissive temperature have an extended life span in culture. Southern blot analysis indicates that the transfected gene is present in low copy number, possibly at a single integration site. Normal stromal cells are capable of 10 to 20 population doublings in culture. Transfected cultures have been carried at the permissive temperature to 80 population doublings before crisis. In the multistep model of malignant transformation of human cells, these cells represent one of the earliest stages: extended but finite life span. We have used these cells to investigate alterations in signal transduction that may be responsible for this early stage of transformation caused by the large T antigen. Temperature shift experiments indicate that the expression of ornithine decarboxylase (ODC) but not of c-fos is altered by the large T antigen. Induction of c-fos by serum or 12-O-tetradecanoylphorbol-13-acetate is independent of temperature. However, in the transfected cells, the induction of ODC by asparagine or serum is greatly enhanced at the permissive temperature. This result indicates that the large T antigen acts downstream of c-fos but upstream of ODC expression in the signal-transducing cascade.

A herald bleed: a case of aortoesophageal fistula and a review of the literature

Survival in AEF is rare because the diagnosis of this uncommon entity is not always suspected, and few patients survive despite aggressive but often late intervention. We present this case to increase awareness of AEF, which although rare, does occur and should be suspected in any patient who presents with midthoracic pain or dysphagia and herald bleeding.

Automated fluorescence image cytometry. DNA quantification and detection of chlamydial infections

Digitized fluorescence microscopy in conjunction with automated image segmentation is a promising approach for screening clinical specimens quickly and reliably. This paper describes the hardware and software of a prototype image-based cytometer that can identify fluorescent objects, discriminate true objects from artifacts and divide overlapping pairs of objects. The use of this image cytometer is discussed for: (1) the measurement of the DNA ploidy distribution of isolated mature rat liver nuclei labeled with 4',6-diamidine-2-phenylindole; (2) the comparison of the DNA ploidy distributions of the same samples measured by image cytometry (ICM) and flow cytometry (FCM); and (3) the quantification of chlamydial infection by double labeling cells with antichlamydiae antibody and Hoechst 33258 for nuclear DNA analysis. Ploidy distributions measured by the automated image cytometer compared favorably to those obtained by FCM. All pairs of overlapping nuclei were automatically detected by an additional computer algorithm, and those pairs that were clearly more than one nucleus by visual inspection were correctly divided. The irregular morphology of the chlamydiae-infected cells meant that 26% of them were not correctly identified in the fluorescein-stained images (as judged by manual inspection), but all cells were nevertheless detected correctly from the images of the Hoechst-stained samples. Automated fluorescence ICM yielded results similar to those obtained with FCM and had the additional benefit of maintaining cell and tissue architecture while preserving the opportunity for subsequent manual inspection of the specimen.

The use of rabbit polyclonal antibodies for the isolation of carcinogen-adducted DNA by immunoprecipitation

Polyclonal rabbit antibodies elicited against DNA with high levels of (+/-) 7r,8t-dihydroxy-9t,10t-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE-I) adducts were used to isolate DNA fragments modified by this carcinogen. DNA treated in vitro with different concentrations of BPDE-I was used as substrate in double-antibody immunoprecipitation reactions. The IgG fraction from immune rabbit serum (primary antibody) was reacted with single-stranded plasmid DNA bearing BPDE-I adducts, and the complexes were immunoprecipitated using goat antirabbit-IgG as secondary antibody. DNA was isolated from the immunoprecipitated pellet, blotted onto nitrocellulose or nylon, and hybridized with 32P-labeled sequences homologous to a fragment of the plasmid DNA used in the assay. The recovery of both DNA and adducts in the immunoprecipitated pellet increased with the level of carcinogen adduction of the DNA. The immunoprecipitation reaction appeared to be more efficient for fragments of DNA containing a high number of adducts. The amount of 32P-hybridizing material recovered by immunoprecipitation was virtually identical to the amount added to the reaction in DNA samples that contained three adducts per 10(3) nucleotides.

Fluorescent laser scanning microscopy of F-actin disruption in human endometrial stromal cells expressing the SV40 large T antigen and the EJ ras oncogene

To attempt to understand the effects of the SV40 large T antigen and an activated EJ ras oncogene on F-actin organization, we compared normal human endometrial stromal cells (HESC; proliferating, short life span) to cells transfected with the SV40 large T antigen either alone or in combination with the EJ ras oncogene. Normal HESC displayed numerous bundles of actin filaments (stress fibers) evenly distributed throughout the cell. In HESC transfected with a plasmid containing the gene for a temperature-sensitive SV40 large T antigen, stress fibers were disrupted and the remaining F-actin was also disrupted and clumped near the plasma membrane. Cells expressing both the SV40 large T antigen and the EJ ras oncogene sometimes appeared rounded, with stress fibers organized mainly near the cell periphery. Under restrictive temperature conditions for the function of the SV40 large T antigen, cells with or without the EJ ras oncogene reorganize actin stress fibers to resemble those of normal HESC. Therefore, the EJ ras oncogene alone does not disrupt F-actin organization. When operating in cooperation with the SV40 large T antigen, however, it leads to the reorganization of F-actin at the cell periphery and confers a rounded structure on the cells.

Ultrastructural characterization of two new human endometrial carcinoma cell lines and normal human endometrial epithelial cells cultured on extracellular matrix

Two new lines of human endometrial carcinoma (HEC) cells, one from an adenocarcinoma and one from a highly metastatic serous papillary carcinoma, were established in culture. Structural and morphologic properties of these cells at early passage were compared with those of cultured normal human endometrial epithelial (NHEE) cells. For these studies, cells were grown on a conventional plastic surface or on an extracellular matrix substrate (Matrigel), and examined by transmission electron microscopy and immunofluorescent light microscopy. The HEC cells appeared morphologically similar on plastic and Matrigel, whereas the NHEE cells showed significantly greater epithelial morphologic differentiation on Matrigel than on plastic. On extracellular matrix, the morphologic differences observed between HEC cells and NHEE cells were primarily of an architectural nature, which may be in part explained by differences between NHEE and HEC cells in the arrangement of actin microfilaments and cytokeratin intermediate filaments. Furthermore, HEC cells displayed extensive networks of vimentin intermediate filaments, which were absent from the NHEE cells. These observations support the hypothesis that architectural deregulation is a prominent feature of endometrial carcinoma, and that cytoskeletal alterations may uncouple HEC cell ultrastructural morphology from the influence of extracellular matrix.

Expression of transforming growth factor beta 1 by human endometrial carcinoma cell lines: inverse correlation with effects on growth rate and morphology

We examined the effects of transforming growth factor beta 1 (TGF-beta 1) on various aspects of the cell biology of human endometrial carcinoma (HEC) cell lines in vitro, as well as the expression of TGF-beta 1 mRNA by these cell lines. Cell lines from eight HEC tumors, representing a variety of histological subtypes, were studied in order to test the generality of conclusions regarding the effects of TGF-beta 1 on this particular tumor cell type. The growth of five HEC cell lines was inhibited by TGF-beta 1 (10 ng/ml), while growth of three cell lines was not inhibited. The effects on growth correlated with morphological alterations induced by TGF-beta 1; the cell lines with inhibited growth displayed a larger, flatter, more contact-inhibited phenotype, while the cell lines whose growth ws not inhibited showed few discernible morphological alterations in response to TGF-beta 1. Northern analysis of TGF-beta 1 mRNA levels revealed that the three HEC cell lines unresponsive to TGF-beta 1 treatment expressed relatively large amounts of TGF-beta 1. Correspondingly, the five HEC cell lines which responded to TGF-beta 1 with growth and morphological changes expressed much lower levels of TGF-beta 1 mRNA. These results suggest that the sensitivity of human HEC cell lines to TGF-beta 1 is variable and that this sensitivity is inversely correlated with the level of expression of TGF-beta 1.

Carcinoma in situ of the testes: diagnosis by aspiration flow cytometry

Carcinoma in situ of the testes has been described as a premalignant state with the potential to progress to invasive carcinoma. A history of testicular carcinoma, cryptorchidism, somatosexual ambiguity and infertility has been identified as a risk factor for carcinoma in situ. A series of 25 infertility patients underwent aspiration biopsy of the testis as part of a study protocol to assess spermatogenesis. Of these patients 1 had a unilateral seminoma. In accordance with the study protocol the contralateral testis was aspirated at radical orchiectomy and the deoxyribonucleic acid histogram generated demonstrated an aneuploid peak. Carcinoma in situ subsequently was noted on tissue biopsy. The discovery of carcinoma in situ cells in this manner highlights the potential of this technique as a diagnostic tool for the screening and followup of men at increased risk for carcinoma in situ.

Malignant transformation of human endometrial stromal cells by transfection of c-myc: effects of pRSVneo cotransfection and treatment with MNNG

Stromal cells isolated from normal human endometrium were cotransfected in primary culture with pSVc-myc, a plasmid containing a truncated c-myc gene regulated by simian virus 40 promoter, and pRSV neo, a plasmid containing a neomycin resistance gene regulated by Rous sarcoma virus (RSV) promoter. These cells demonstrated properties of transformed cells in vitro, including altered morphology, focus formation, anchorage-independent growth, chromosomal alterations, and tumor formation in athymic mice. When these cells were treated subsequently with a direct-acting carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine, they demonstrated higher colony-forming efficiency in soft agar and reduced tumor latency. Cells transfected with pRSV neo alone exhibited some properties associated with neoplastic transformation, including altered morphology and formation of colonies in soft agar. It is presumed that in normal cells transfected with pRSV neo, RSV long terminal repeats activated cellular genes that normally regulate growth of human endometrial stromal cells.

Establishment and characterization of a human cell line from a serous papillary endometrial carcinoma

The cell line SPEC-1, derived from a human serous papillary endometrial carcinoma (SPEC), has been established and repetitively subcultured for over 18 months. SPEC is a clinically aggressive histologic variant of endometrial adenocarcinoma with a significantly poorer prognosis. The SPEC cells exhibit morphologic and ultrastructural characteristics of transformed epithelial cells. The cells were further characterized with regard to growth kinetics, histochemistry, karyotype, and tumorigenicity. These studies indicate that several properties of the SPEC cells in culture contrast markedly with those of both typical endometrial adenocarcinoma cell lines and normal endometrial epithelia, as described in the literature. The most significant of these differences concern cytogenetic and ultrastructural features. The implications of these unique characteristics are discussed with regard to the relationship they may have to the unusually aggressive biological behavior of this tumor cell type in vivo. This SPEC cell line should prove useful in future studies designed to determine important factors in the biological behavior of human tumor cells.

Ferritin-labeled rabbit Fab fragments for the single-step detection of benzo[a]pyrene-diol-epoxide adducts in DNA by electron microscopy

In this paper we describe an immunological method for the visualization of (+/-)7 beta, 8 alpha-dihydroxy-9 alpha, 10 alpha-epoxy-7,8,9,10- tetrahydrobenzo[a]pyrene (BPDE-I) adducts in DNA by electron microscopy (EM). The immunoglobulin fraction of rabbit antiserum specific for BPDE-I adducts was digested with papain, the Fab fragments were purified by affinity chromatography on protein A-Sepharose and cross-linked to ferritin. The reactivity of the Fab fragments coupled to ferritin was determined by using anti-ferritin antibodies to precipitate the complexes formed between ferritin-labeled Fab fragments and BPDE-I-modified DNA that had been uniformly labeled with [14C]thymidine. DNA from cells treated with BPDE-I in culture was reacted with ferritin-labeled Fab fragments, separated from unreacted Fab using a Sepharose CL-4B column, and examined by EM. An aliquot of the same DNA was used to determine the level of BPDE-I adduction using an enzyme-linked immunosorbent assay (ELISA). Close agreement was found between the levels of adduction determined by ELISA and EM. A good correlation was also found between the level of adduction measured by EM and scintillation spectrometry when DNA was modified with [3H]BPDE-I in vitro. The EM method presents the following advantages: (i) it avoids cross-linking of separate adducts by the same IgG molecule; and (ii) it requires only one antigen-antibody reaction and a single purification step, allowing analysis of very small amounts of DNA.

Gland formation from human endometrial epithelial cells in vitro

We have developed methods for the culture of human endometrial glandular epithelia in vitro. The culture medium is serum-free and is used in combination with Matrigel, an extracellular matrix material applied as a coating on cell culture plates. Cell growth begins as a monolayer, but the cells subsequently form glandular or organoid structures. The glands are composed of polar columnar cells facing a central lumen, which is enclosed by the apical surfaces of cells displaying numerous microvilli and sealed by tight junction complexes. The ability to study in vitro the complex process of glandular morphogenesis represents an important new tool in cell biology which may be used to investigate growth regulation, hormone production and dependency, and cellular recognition and interactions. Ultimately, these characteristics may be applied to study the alterations of glandular epithelia associated with neoplasia.

Phenobarbital-dependent proliferation of putative initiated rat hepatocytes

The mitogenic effects of phenobarbital (PB) were examined using cultures of putative initiated hepatocytes that proliferate and form colonies under conditions in which normal hepatocytes senesce and die. The frequencies of colony-forming hepatocytes in primary cultures isolated 2 weeks after initiation with methyl(acetoxymethyl)nitrosamine or benzo[a]pyrene-7,8-diol-9,10-epoxide(anti) were in the range of 2-38 per million in the presence of PB. Colony-formation frequencies were 0.1 per million in the absence of PB. Proliferative hepatocyte colonies were not observed in cultures grown in serum-free medium containing PB, epidermal growth factor, nor-epinephrine and insulin. The requirement for PB was characterized further using secondary cultures of hepatocytes that had been isolated from a liver 5 weeks after initiation. The colony-forming efficiency of these hepatocytes was about 10% in the presence of 2 mM PB and less than 0.2% in its absence. Colony formation displayed a linear response to concentrations of PB in the range of 0.5-2 mM and a decline above the optimal 2 mM concentration. Autoradiography was used to determine the percentages of hepatocytes in secondary cultures that synthesized DNA in the presence or absence of PB. By the third day after seeding as single cells, hepatocytes exhibited a labeling index of about 50% and this level of labeling was preserved for up to 2 weeks after seeding. Very few hepatocytes were found to synthesize DNA in the absence of PB and most senesced. A small fraction of the colony-forming hepatocytes continued to proliferate in the absence of PB and formed colonies with a high labeling index. These results suggest that the proliferation of initiated hepatocytes in vivo may be conditional upon the presence of the hepatic tumor promoter, PB.