P93 THE POWER OF GROUP WORK IS THE STRENGTH OF A SUCCESS: TAVI!

TAVI (Transcatheter Aortic Valve Implantation) is a procedure performed by a multidisciplinary team, preferably in a hybrid room where both interventional and cardiac surgery procedures are performed. This procedure is a splendid example of team work, where all the figures involved (hemodynamist, cardiac surgeon, anesthetist, sonographer and nurses) collaborate, each with a specific role, in the safe execution of the implantation of the transcatheter aortic valve in patients with high operative risk. Specifically, during the TAVI there are 4 nurses with very specific roles: CIRCULATING NURSE: • He/she welcomes the patient in pre–operating room (identification, checklist) • He/she transfers the patient to the hybrid room (positioning, etc.) • He/she supports the scrub nurse (materials, Pacemaker management) • He/she performs TIME–OUT and SIGN–OUTANESTHESIA NURSE: • He/she takes care of positioning all the monitoring instruments (ECG plates, defibrillator, etc. ..), finds all the venous accesses and supports the anesthetist (ventilation, intubation if necessary, EGA, ACT, etc …)SCRUB NURSE: • He/she collaborates with the hemodynamist in the execution of the procedure and in the management of sterile materials.CRIMPER NURSE: • He/she is responsible for the correct preparation of the valve and the material required for its assembly. This “new” competence of the nurse sees him engaged in the following activities: 1. preparation of the overbed table 2. preparation of catheters, introducers and any catheters for pre–dilatation (valvuloplasty) 3. preparation of valve delivery and positioning systems 4. valve washing 5. assembly and “crimping” of the valve

At the end of the procedure, the nurses carry out the compressive dressing of the arterial and venous accesses, monitor and verify the correct arterial haemostasis by promptly intervening on any vascular complications (haemorrhages, pseudoaneurysms). Since October 2017, our Center has carried out numerous procedures with intra–operative and post–operative results comparable to national data, thanks to the efforts and commitment of our Heart Team. TAVI turns out to be an excellent example of teamwork, where success is given by the synergy between the various professional figures that are essential to each other.

Immunohistochemical Analysis of DNA Repair- and Drug-Efflux-Associated Molecules in Tumor and Peritumor Areas of Glioblastoma

Glioblastoma (GBM), the most commonly occurring primary tumor arising within the central nervous system, is characterized by high invasiveness and poor prognosis. In spite of the improvement in surgical techniques, along with the administration of chemo- and radiation therapy and the incessant investigation in search of prospective therapeutic targets, the local recurrence that frequently occurs within the peritumoral brain tissue makes GBM the most malignant and terminal type of astrocytoma. In the current study, we investigated both GBM and peritumoral tissues obtained from 55 hospitalized patients and the expression of three molecules involved in the onset of resistance/unresponsiveness to chemotherapy: O6-methylguanine methyltransferase (MGMT), breast cancer resistance protein (BCRP1), and A2B5. We propose that the expression of these molecules in the peritumoral tissue might be crucial to promoting the development of early tumorigenic events in the tissue surrounding GBM as well as responsible for the recurrence originating in this apparently normal area and, accordingly, for the resistance to treatment with the standard chemotherapeutic regimen. Notably, the inverse correlation found between MGMT expression in peritumoral tissue and patients’ survival suggests a prognostic role for this protein.

Pivotal role of human stearoyl-CoA desaturases (SCD1 and 5) in breast cancer progression: oleic acid-based effect of SCD1 on cell migration and a novel pro-cell survival role for SCD5

The influence of cell membrane fluidity on cancer progression has been established in different solid tumors. We previously reported that “cancer-associated fibroblasts” (CAFs) induced epithelial-mesenchymal transition and increased cell membrane fluidity and migration in poorly (MCF-7) and highly invasive (MDA-MB-231) breast cancer cells. We also found that the membrane fluidity regulating enzyme stearoyl-CoA desaturase 1 (SCD1) was upregulated in tumor cells co-cultured with CAFs and established its essential role for both intrinsic and CAF-driven tumor cell motility. Here, we further explored the mechanisms involved in the SCD1-based modulation of breast cancer cell migration and investigated the role of the other human SCD isoform, SCD5. We showed that the addition of oleic acid, the main SCD1 product, nullified the inhibitory effects produced on MCF-7 and MDA-MB-231 cell migration by SCD1 depletion (pharmacological or siRNA-based). Conversely, SCD5 seemed not involved in the regulation of cancer cell motility. Interestingly, a clear induction of necrosis was observed as a result of the depletion of SCD5 in MCF-7 cells, where the expression of SCD5 was found to be upregulated by CAFs. The necrotic effect was rescued by a 48-h treatment of cells with oleic acid. These results provide further insights in understanding the role of SCD1 in both intrinsic and CAF-stimulated mammary tumor cell migration, unveiling the metabolic basis of this desaturase-triggered effect. Moreover, our data suggest the ability of CAFs to promote the maintenance of tumor cell survival by the induction of SCD5 levels.

Proliferating fibroblasts and HeLa cells co-cultured in vitro reciprocally influence growth patterns, protein expression, chromatin features and cell survival

AIM

to identify biological interactions between proliferating fibroblasts and HeLa cells in vitro.

MATERIALS AND METHODS

Fibroblasts were isolated from both normal and tumour human tissues. Coverslip co-cultures of HeLa and fibroblasts in various ratios with medium replacement every 48 h were studied using fixed cell staining with dyes such as Giemsa and silver staining, with immunochemistry for Ki-67 and E-cadherin, with dihydrofolate reductase (DHFR) enzyme reaction, as well as live cell staining for non-specific esterases and lipids. Other techniques included carmine cell labeling, autoradiography and apoptosis assessment.

RESULTS

Under conditions of feeding and cell: cell ratios allowing parallel growth of human fibroblasts and HeLa cells, co-cultured for up to 20 days, a series of phenomena occur consecutively: profound affinity between the two cell types and exchange of small molecules; encircling of the HeLa colonies by the fibroblasts and enhanced growth of both cell types at their contact areas; expression of carbonic anhydrase in both cell types and high expression of non-specific esterases and cytoplasmic argyrophilia in the surrounding fibroblasts; intense production and secretion of lipid droplets by the surrounding fibroblasts; development of a complex net of argyrophilic projections of the fibroblasts; E-cadherin expression in the HeLa cells; from the 10th day onwards, an increasing detachment of batches of HeLa cells at the peripheries of colonies and appearance of areas with many multi-nucleated and apoptotic HeLa cells, and small HeLa fragments; from the 17th day, appearance of fibroblasts blocked at the G2-M phase. Co-cultures at approximately 17-20 days display a cell-cell fight with foci of (a) sparse growth of both cell types, (b) overgrowth of the fibroblasts and (c) regrowth of HeLa in small colonies. These results indicate that during their interaction with HeLa cells in vitro, proliferating fibroblasts can be activated against HeLa. This type of activation is not observed if fibroblast proliferation is blocked by contact inhibition of growth at confluency, or by omitting replacement of the nutrient medium.

CONCLUSION

The present observations show that: (a) interaction between proliferating fibroblasts and HeLa cells in vitro drastically influences each other's protein expression, growth pattern, chromatin features and survival; (b) these functions depend on the fibroblast/HeLa ratio, cell topology (cell-cell contact and the architectural pattern developed during co-culture) and frequent medium change, as prerequisites for fibroblast proliferation; (c) this co-culture model is useful in the study of the complex processes within the tumour microenvironment, as well as the in vitro reproduction and display of several phenomena conventionally seen in tumour cytological sections, such as desmoplasia, apoptosis, nuclear abnormalities; and (d) overgrown fibroblasts adhering to the boundaries of HeLa colonies produce and secrete lipid droplets.

Isolation of cancer stem cells from three human glioblastoma cell lines: characterization of two selected clones

Cancer stem cells (CSC) were isolated via a non-adherent neurosphere assay from three glioma cell lines: LI, U87, and U373. Using a clonal assay, two clones (D2 and F11) were selected from spheres derived from LI cells and were characterized for the: expression of stem cell markers (CD133, Nestin, Musashi-1 and Sox2); proliferation; differentiation capability (determined by the expression of GalC, βIII-Tubulin and GFAP); Ca²⁺ signaling and tumorigenicity in nude mice. Both D2 and F11 clones expressed higher levels of all stem cell markers with respect to the parental cell line. Clones grew more slowly than LI cells with a two-fold increase in duplication time. Markers of differentiation (βIII-Tubulin and GFAP) were expressed at high levels in both LI cells and in neurospheres. The expression of Nestin, Sox2, and βIII-Tubulin was down-regulated in D2 and F11 when cultured in serum-containing medium, whereas Musashi-1 was increased. In this condition, duplication time of D2 and F11 increased without reaching that of LI cells. D2, F11 and parental cells did not express voltage-dependent Ca²⁺-channels but they exhibited increased intracellular Ca²⁺ levels in response to ATP. These Ca²⁺ signals were larger in LI cells and in spheres cultured in serum-containing medium, while they were smaller in serum-free medium. The ATP treatment did not affect cell proliferation. Both D2 and F11 induced the appearance of tumors when ortotopically injected in athymic nude mice at a density 50-fold lower than that of LI cells. All these data indicate that both clones have characteristics of CSC and share the same stemness properties. The findings regarding the expression of differentiation markers and Ca²⁺-channels show that both clones are unable to reach the terminal differentiation. Both D2 and F11 might represent a good model to improve the knowledge on CSC in glioblastoma and to identify new therapeutic approaches.

Interactions between normal human fibroblasts and human prostate cancer cells in a co-culture system

BACKGROUND

Stroma affects the development and the structure of many organs and plays an important role in regulating epithelial malignancies, including those derived from the prostate. Fibroblasts represent the major cell type of the stromal compartment. Aiming at clarifying the relationships between normal fibroblasts and epithelial cancer cells, we utilized a co-culture system, which included both androgen-sensitive (LNCaP) and -insensitive (PC-3, DU-145) prostate cancer cell lines and a human gingival fibroblast cell line (FG).

MATERIALS AND METHODS

The morphological aspects of the cultures were analyzed under an inverted phase-contrast microscope; the proliferation in conditioned media (CM) was assessed by cell counts, and the E-cadherin expression was evaluated by immunocytochemistry.

RESULTS

In co-culture, androgen-sensitive LNCaP cells grew in a network on the top of the monolayer formed by FG, while colonies of androgen-insensitive PC-3 and DU-145 cells were surrounded by FG cells. After six days, the LNCaP cell number was apparently lower in the co-cultures than in the plates where they grew alone. Both LNCaP and FG cells underwent morphological changes. After the same period of time, the growth of PC-3 and DU-145 cells overcame the growth of FG cells, which were almost abolished. The CM of FG inhibited the proliferation of LNCaP cells, after three days by 33% (p<0.01) and after six days by up to 82% (p<0.01), but had no effect on the PC-3 and DU-145 cell growth. The CM of all three prostate cancer cell lines reduced the growth of FG. Growth reduction in DU-145 cells was the most effective (50% inhibition after three days, p<0.01, and 55% after six days, p<0.01). FG did not express E-cadherin, while strong E-cadherin staining was detected in LNCaP cells. PC-3 cells exhibited E-cadherin nuclear staining, while sporadic membrane expression of the specific protein was observed in DU-145 cells. In co-culture, there seemed to be a reduction in the nuclear E-cadherin reactivity of PC-3 cells.

CONCLUSION

Our data confirm the existence of a dialogue between normal fibroblasts and prostate cancer cells, which results in both a peculiar modality of growth and a regulation of proliferation, probably due to factors secreted in the culture medium. The variation in E-cadherin expression found in PC-3 cells co-cultured with FG merits further investigation.

Soluble E-cadherin and IL-6 serum levels in patients affected by prostate cancer before and after prostatectomy

Prostate specific antigen (PSA) is still the best available tumour marker in prostate cancer (PCa), but presents some limits. Therefore, there is a need for novel markers in the detection and management of PCa. The 80-kDa soluble form of E-cadherin (sE-cad) and the cytokine IL-6 are being discussed as supplemental serum markers for PCa. In this study, sE-cad and IL-6 serum levels were determined in patients with pathological localized or locally advanced PCa without any previous treatment. These patients underwent radical retropubic prostatectomy (RRP) in accordance with the EAU Guidelines on Prostate Cancer. The molecules were determined via immunoenzymatic assays in samples collected before and after surgery. Statistical analysis was performed by Student's t-test and Pearson's correlation test. sE-cad levels were 6.0 ± 2.7 and 4.6 ± 2.3 µg/ml, before and after RRP, respectively. A highly statistically significant decrease in sE-cad concentrations after RRP was observed (p<0.0001), in 50/61 patients (82%). sE-cad levels before and after surgery were correlated (Pearson's correlation coefficient, r=0.6993, p<0.0001). sE-cad values detected after surgery were higher in patients with PSA levels >10 ng/ml (p<0.05). sE-cad levels before RRP were significantly higher in patients with G3 tumours compared to those with G2 tumours (p<0.02). Finally, sE-cad concentrations both before and after surgery were higher in tumours with Gleason score =7 compared to those with Gleason score <7 (p<0.002 and p<0.05, respectively). Preliminary data from 20 patients indicated a statistically significant increase in IL-6 levels after RRP (11.2 vs. 7.2 pg/ml, p<0.001). This is the first study on the reduction in sE-cad levels after RRP in PCa patients. Moreover, it shows that preoperative sE-cad concentrations are higher in patients with less differentiated PCa. Promising findings of this pilot study may lead to investigation of sE-cad in a larger study with follow-up.

Leuprorelin acetate affects adhesion molecule expression in human prostate cancer cells

Reduced cell-cell adhesion allows malignant epithelial cells to invade the basal membrane and penetrate the stroma. This implies the potential of the cells to escape from the primary tumor as well as spreading ability. Herein, we investigated the effects of leuprorelin acetate (LA), a GnRH agonistic analogue, alone or in combination with dihydrotestosterone (DHT), on the expression of molecules involved in cell adhesion (E-cadherin, N-cadherin, α-, β- and γ-catenin) or in migration/invasion (c-met, CD44v6 and caveolin-1) in androgen-sensitive (LNCaP) and -insensitive (PC-3) prostate cancer (CaP) cells. We demonstrated by immunoblotting that, in LNCaP cells, molecules present in the adherens junctions (E-cadherin, α-, β- and γ-catenin) were expressed, while α-catenin was absent in PC-3 cells which expressed N-cadherin and c-met. In LNCaP cells, no changes in E-cadherin levels were produced by 10(-9) M DHT while LA (10(-11) or 10(-6) M) up-regulated the protein level (up to 26-30% after 48 h). In the same cells, β- and γ-catenin expression was enhanced either by DHT (24 and 20%, respectively) or LA (up to 18 and 40%, respectively), while α-catenin was not affected. Antagonistic effects were consistently observed between DHT and LA when the two hormones were jointly administered to the cells. Consistent results were obtained by immunocytochemistry. Co-immunoprecipitation analysis, used to verify the integrity of the LNCaP cell adhesion complex, demonstrated the association of E-cadherin with catenins. In PC-3 cells, adhesion molecule expression, analyzed by immunoblotting, was unaffected by LA, while a down-regulation of c-met (up to 28%) was observed after 24 h of treatment but which did not hold up over time (48-144 h). Our findings demonstrate the efficacy of LA in upregulating E-cadherin, β- and γ-catenin in LNCaP cells. This effect, that may be considered as another aspect of the direct antitumor activity of the GnRH analogue in hormone-dependent CaP cells, may contribute to maintenance/restoration of the normal tissue architecture counteracting the tumor cell spreading tendency.

GnRH receptor expression in human prostate cancer cells is affected by hormones and growth factors

GnRH receptors (GnRH-R) have been found in various malignancies, including prostate cancer (PCa). They mediate the direct antitumor effects of GnRH analogs. Nevertheless, few reports concern drug-induced modulation of GnRH-R levels. In this study, we investigated GnRH-R expression in androgen-sensitive (LNCaP) and -insensitive (PC-3) PCa cells treated for 4 and 6 days with a GnRH agonist (Leuprorelin acetate, LA, 10(-11) or 10(-6) M), Dihydrotestosterone (DHT, 10(-9) M), Cyproterone acetate (CA, 10(-7) M), and Epidermal growth factor (EGF, 10 ng/ml), either alone or combined. The RT-PCR analysis showed no variation in GnRH-R mRNA levels of both treated LNCaP and PC-3 cells. On the contrary, immunoblotting indicated that in LNCaP and PC-3 cells, LA upregulated membrane GnRH-R expression (up to 92%). In androgen-sensitive cells, DHT induced a GnRH-R increase (up to 119%) always comparable to that occurring in the presence of CA. GnRH-R upregulation by LA/DHT or CA/DHT association was similar to that promoted by the single agents. In PC-3 cells, EGF upregulated GnRH-R (up to 110%). A prolonged treatment (for 12 days) determined a greater EGF-induced increase in GnRH-R levels (142%). Lower (or no) receptor enhancement occurred when LA and EGF were associated. Our findings indicate that LA post-transcriptionally upregulates its own membrane receptor in androgen-sensitive and -insensitive PCa cells, counteracting the receptor enhancement produced by DHT and EGF. The effects, obtained with a relatively long and continuous treatment, may have implications in the choice of therapy modality with GnRH analogs and may render the receptor a novel therapeutic target, particularly in hormone-refractory PCa.

Valproic acid activity in androgen-sensitive and -insensitive human prostate cancer cells

Histone deacetylase (HDAC) inhibitors are currently undergoing clinical trials in cancer patients on the basis of their effect on proliferation, differentiation and apoptosis demonstrated in vitro. The goal of this study was to assess the effects of an HDAC inhibitor, valproic acid (VA), on proliferation, androgen-sensitivity, androgen receptor levels and E-cadherin (E-cad) expression in human prostate cancer cells. The effects of VA were evaluated in androgen-sensitive, LNCaP and -insensitive PC-3 human prostate cancer cell lines. Proliferation was assayed by cell counts and protein expression by Western blot analysis. Morphological changes were analysed under an inverted phase contrast microscope. High VA concentrations (1-25 mM) induced a very strong reduction in cell numbers ( approximately 90% with respect to control) of the two cell lines due to drug cytotoxicity. A low concentration (0.45 mM VA) slightly reduced (14%) LNCaP cell proliferation and abolished the response to androgen. In the PC-3 cells, the same concentration of VA had a more pronounced (40%) inhibitory effect and induced a response to dihydrotestosterone in terms of an enhancement in cell growth. These events were associated with morphological changes, an absence of cytotoxicity, an increase in androgen receptor levels, and, in PC-3 cells, an enhancement in E-cad expression which may be ascribed to VA differentiative action. Our findings, obtained with a VA dose (0.45 mM), which is consistent with plasma concentrations reached under oral administration of therapeutical doses in patients treated for different diseases, suggest that VA might have clinical value in prostate cancer therapy in androgen-sensitive and -insensitive tumors.

Valproic acid activity in androgen-sensitive and -insensitive human prostate cancer cells

Histone deacetylase (HDAC) inhibitors are currently undergoing clinical trials in cancer patients on the basis of their effect on proliferation, differentiation and apoptosis demonstrated in vitro. The goal of this study was to assess the effects of an HDAC inhibitor, valproic acid (VA), on proliferation, androgen-sensitivity, androgen receptor levels and E-cadherin (E-cad) expression in human prostate cancer cells. The effects of VA were evaluated in androgen-sensitive, LNCaP and -insensitive PC-3 human prostate cancer cell lines. Proliferation was assayed by cell counts and protein expression by Western blot analysis. Morphological changes were analysed under an inverted phase contrast microscope. High VA concentrations (1-25 mM) induced a very strong reduction in cell numbers ( approximately 90% with respect to control) of the two cell lines due to drug cytotoxicity. A low concentration (0.45 mM VA) slightly reduced (14%) LNCaP cell proliferation and abolished the response to androgen. In the PC-3 cells, the same concentration of VA had a more pronounced (40%) inhibitory effect and induced a response to dihydrotestosterone in terms of an enhancement in cell growth. These events were associated with morphological changes, an absence of cytotoxicity, an increase in androgen receptor levels, and, in PC-3 cells, an enhancement in E-cad expression which may be ascribed to VA differentiative action. Our findings, obtained with a VA dose (0.45 mM), which is consistent with plasma concentrations reached under oral administration of therapeutical doses in patients treated for different diseases, suggest that VA might have clinical value in prostate cancer therapy in androgen-sensitive and -insensitive tumors.

Recombinant Human IFN-βAffects Androgen Receptor Level, Neuroendocrine Differentiation, Cell Adhesion, and Motility in Prostate Cancer Cells

We provide evidence that recombinant human interferon-beta (rHuIFN-beta) is able to increase androgen receptor (AR) expression, interfere with the acquisition of a neuroendocrine (NE) phenotype, and improve adhesion potential of androgen-insensitive prostate cancer cells (PC-3). The effect of rHuIFN-beta (10-1000 IU/mL) on AR, chromogranin A (CgA), E-cadherin (E-cad), N-cadherin (N-cad), and c-met levels was investigated by Western blotting after 48, 96, and 144 h. In agreement with our previous results, rHuIFN-beta (10-1000 IU/mL) induced a dramatic increase in AR (up to 5.3-fold, p < 0.001) that was already evident with the lowest cytokine concentration (10 IU/mL). A reduction in CgA levels (up to 45%, p < 0.002) was produced by 100 and 1000 IU/mL after 48-144 h. E-cad upregulation (up to 90%, p < 0.05) was observed starting from 96 h of treatment with 100 and 1000 IU/mL rHuIFN-beta and persisted until 144 h. An rHuIFN-beta-dependent reduction occurred in N-cad and c-met signal after a 48-96 h of treatment. This effect was particularly strong after 144 h of exposure to 1000 IU/mL rHuIFN-beta (81.5%, N-cad; 58%, c-met) (p < 0.002). Reverse transcription-PCR (RT-PCR) analysis of c-met expression demonstrated that the IFN-induced c-met downregulation mostly occurs at the transcriptional level (reduction up to nearly 50%, p < 0.000). Together, these results indicate that rHuIFN-beta may reduce the motility and invasiveness of poorly differentiated prostate cancer cells and interfere with the acquisition of an NE phenotype, often characterized by a low AR level.

Leuprorelin acetate affects ERK1/2 activity in prostate cancer cells

The mechanisms by which a GnRH analogue, leuprorelin acetate (LA), antagonizes the mitogenic effect of dihydrotestosterone (DHT) or epidermal growth factor (EGF) in prostate cancer cells is poorly understood. The mitogen-activated protein kinase system has a central role in growth regulation and, for this reason, we investigated the involvement of the extracellular signal-regulated kinase (ERK1/2) pathway in the response of both androgen-sensitive (LNCaP) and -insensitive (PC-3) prostate cancer cells to LA alone or combined with EGF or DHT. The evaluation of ERK activation was performed by using Western blot analysis and immunocytochemistry. EGF specifically induced ERK1/2 activity in both models and this effect was counteracted by an inhibitor of EGF-receptor phosphorylation. The addition of LA produced an appreciable reduction of ERK phosphorylation promoted by EGF in LNCaP cells, while it generally determined an increase in ERK activity in androgen-unresponsive PC-3 cells. The slight ERK activation induced by DHT in LNCaP cells was counteracted by LA and this effect was evident only by immunocytochemistry. Our findings suggest that the antiproliferative effect of LA in prostate cancer cells stimulated by hormones and growth factors may be, at least in part, mediated by the reduction of ERK1/2 activation in LNCaP cells and linked to the unexpected increase of this activity produced by the analogue in PC-3 cells.

Apoptosis-related gene expression in benign prostatic hyperplasia and prostate carcinoma

BACKGROUND

The aim of this study was to examine the expressions of the bcl-2, bax, fas and c-myc apoptosis-related genes in benign prostatic hyperplasia (BPH) and prostate carcinoma (CaP) to determine whether significant differences exist within each disease and between the two groups of patients. The correlation between gene expression and tumour diameter, stage, Gleason score and serum PSA was also investigated.

PATIENTS AND METHODS

Tissue specimens from 51 cases of BPH and 27 cases of CaP were examined for bcl-2, bax, fas and c-myc expression by reverse transcriptase-PCR (RT-PCR).

RESULTS

In BPH, bcl-2 and bax gave the weakest signals (p < 0.001). In CaP, bcl-2 was the least expressed gene (p < 0.001). In both patient groups, fas and c-myc were the most highly expressed genes (p < 0.05). Both bcl-2 and bax were expressed at higher levels in CaP than in BPH (p < 0.02). The bcl-2/bax ratio was lower in CaP than in BPH (p < 0.001). Bcl-2 was more highly expressed in high Gleason grade (> 7) tumours (p < 0.05). In the BPH group, bax showed a positive relationship with fas (p < 0.01), while the bcl-2 level inversely correlated with that of c-myc (p < 0.05).

CONCLUSION

Our data showed that all the apoptosis-related genes were expressed in both BPH and CaP. The stronger expression of bax and the lower bcl-2/bax ratio observed in CaP may suggest a pro-apoptotic stimulus, while the higher bcl-2 levels appear to counterbalance the tendency to cell death.

Reverse transcriptase-PCR analysis of apoptosis-regulating gene expression in human benign prostatic hyperplasia

BACKGROUND

To determine whether an imbalanced interaction between proapototic and antiapoptotic signals may account for the loss of the normal cell growth control in benign prostatic hyperplasia (BPH), the expression of some apoptosis-regulating genes (bcl-2, bax, c-myc, fas) was investigated.

PATIENTS AND METHODS

BPH specimens were obtained from 20 patients who underwent trans-urethral resection of the prostate (TURP) or adenomectomy. Gene expression was studied by reverse transcriptase-polymerase chain reaction (RT-PCR) and its correlation with age and serum PSA level was also investigated.

RESULTS

Genes were found to be differentially expressed in BPH tissues. In particular, the antiapoptotic gene bcl-2, which was found in 18/20 samples, gave the weakest signal (p < 0.05 - p < 0.001, Wilcoxon's signed rank test), whereas the cell cycle regulator c-myc was detected in all the specimens and was the most highly expressed (p < 0.001). A positive relationship between the expression of bcl-2 and that of the two proapoptotic genes bax and fas was observed (p < 0.05, Spearman's rank correlation test), as well as between c-myc and fas levels (p < 0.005). Moreover, bax expression positively correlated with age and PSA (p < 0.02), which have also been shown to directly correlate (p < 0.01).

CONCLUSION

The higher expression of the oncogene c-myc suggests the activation of mitogenic signals within hyperplastic prostate tissue which a relatively high expression of the proapoptotic genes bax and fas fails to counterbalance.

Apoptosis-related gene expression affected by a GnRH analogue without induction of programmed cell death in LNCaP cells

BACKGROUND

In this study we confirmed the ability of a Gonadotropin Releasing Hormone (GnRH) agonist, leuprorelin acetate (LA), to counteract or even suppress the 5alpha-dihydrotestosterone (DHT)-stimulated growth of androgen-sensitive prostate cancer cells (LNCaP). Since the cellular mechanisms mediating this effect are not well defined, we investigated the activity of LA, also in combination with DHT or with cyproterone acetate (CA), on the expression of genes (bcl-2, bax, c-myc) which may contribute to the proliferative behaviour of LNCaP cells. In addition, experiments aimed to evaluate the action of the analogue on apoptosis were performed.

MATERIALS AND METHODS

Gene expression was evaluated by RT-PCR and Western blotting on cells treated with LA (10(-11) or 10(-6) M), alone or combined with 10(-9) M DHT or 10(-7) M CA. The occurrence of apoptosis following treatment with LA (10(-11), 10(-6) or 10(-5) M), alone or combined with 10(-9) M DHT, was assessed by DNA fragmentation analysis.

RESULTS

Both the mRNA and protein of the anti-apoptotic gene bcl-2 were induced (30-125%) by DHT after 24-144 h. LA decreased bcl-2 mRNA (10-40%), while it did not unequivocally affect protein expression. The analogue always reduced (13-74%) both mRNA and protein levels obtained under DHT treatment. The mRNA and protein of the pro-apoptotic gene bax were down-regulated by DHT (15-40%), while LA generally induced bax protein but not its mRNA. LA counteracted DHT activity, even increasing bax protein levels over the controls. c-myc mRNA and protein were enhanced by DHT (15-45%) but down-regulated by LA (10-40%). Once more, the androgen effect was antagonized by LA, sometimes reducing c-myc content below the controls. CA produced the most similar effects to those triggered by DHT. The hormonal treatment did not induce any DNA fragmentation.

CONCLUSION

In spite of gene modulation, apoptosis was not observed under LA treatment, in agreement with the lack of a cell growth effect when the analogue was used alone. Nevertheless, the observed changes in gene expression may be directly or indirectly involved in the antiproliferative effect of LA on androgen-stimulated cells.

Regulation of prostate-specific antigen gene expression by an LH-RH analogue in human prostatic cells

BACKGROUND

We investigated the regulation of prostate-specific antigen (PSA) gene expression in prostatic tumor cells by an LH-RH analogue, Leuprorelin acetate (LH-RHa), alone or combined with dihydrotestosterone (DHT).

MATERIALS AND METHODS

PSA gene expression was evaluated by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) in androgen-sensitive LNCaP and androgen-insensitive PC-3 cells.

RESULTS

LH-RHa at both high and low concentrations induced a diminution in the levels of PSA gene expression which reached 70% in androgen-insensitive PC-3 cells. The analogue lowered the levels of expression obtained under DHT stimulation in LNCaP cells. These effects were visible from 6-24 hours of treatment and persisted until 120 hours.

CONCLUSION

PSA gene expression is directly regulated by LH-RHa in both LNCaP and PC-3 cells. High concentrations of the analogue are particularly effective, but low doses of the drug have a similar behaviour. Interestingly, Leuprorelin acetate is able to counteract the androgen-induced gene expression. Our results suggest that, at least in androgen-sensitive cells, the analogue may regulate PSA gene expression also by interfering with the androgen receptor machinery.

Direct effects of GnRH agonists in human hormone-sensitive endometrial cells

The antiproliferative effect of two GnRH agonists (leuprorelin acetate and triptorelin), alone or combined with tamoxifen (TAM) or medroxyprogesterone acetate (MPA), on human estrogen-sensitive endometrial cancer cells (Ishikawa) was investigated. Although ineffective when tested alone in all the culture conditions used, both analogues counteracted or even suppressed the estrogen-stimulated growth of Ishikawa cells. The antiestrogenic effect of TAM or MPA was not modified by their association with high doses of the GnRH analogues, but low concentrations of triptorelin combined with MPA 10(-7) M determined a reduction in cell numbers which was greater than that obtained with the progestin or the analogue alone. In addition, analogue treatment prevented the estrogen-induced decrease in the level of estrogen receptors. Our data provide evidence that GnRH agonists can directly inhibit estrogen-stimulated endometrial cancer cell growth and suggest that they may interfere with steroid-receptor machinery.

Effect of placenta growth factor-1 on proliferation and release of nitric oxide, cyclic AMP and cyclic GMP in human epithelial cells expressing the FLT-1 receptor

We investigated the effect of placenta growth factor-1 (P1GF-1) on cell growth and on the release of nitric oxide (NO), cyclic AMP (cAMP) and cyclic GMP (cGMP) in human malignant epithelial cells. A noteworthy increase in proliferation was induced in choriocarcinoma cells (BeWo) by P1GF-1 treatment, while breast cancer cells (CG-5) were minimally affected. Western blotting and immunocytochemistry demonstrated the expression of the P1GF-1 receptor fms-like tyrosine kinase-1 (Flt-1) in these models. NO was released in the BeWo culture medium as a result of P1GF-1 treatment, with maximal induction occurring after 6 h. Enhanced cAMP levels were observed after 80 min-6 h, while the amounts of cGMP produced were undetectable. In summary, PIGF-1 stimulates the proliferation of cell types that express Flt-1, other than endothelial cells. In BeWo cells, this effect is preceded by the induction of NO and cAMP as probable downstream effectors of Flt-1 activation.

Effect of leuprorelin acetate on cell growth and prostate-specific antigen gene expression in human prostatic cancer cells

OBJECTIVES

We investigated modulation of cell growth and prostate-specific antigen (PSA) gene expression in prostatic cancer cells by the luteinizing hormone-releasing hormone analog (LH-RHa), leuprorelin acetate, alone or combined with other agents.

METHODS

The effect of the analog on proliferation of both androgen-sensitive and -insensitive prostate cancer cells, maintained in different culture conditions, was evaluated by cell counts at various intervals of time. Basal expression of PSA gene and its variations were determined by a reverse transcriptase-polymerase chain reaction assay.

RESULTS

LH-RHa is ineffective in regulating cell growth, when used alone in both hormone-sensitive and -insensitive cell lines. Nevertheless, it counteracts the stimulatory action of androgens on proliferation of LNCaP cells, which respond to low concentrations of dihydrotestosterone. Moreover, LH-RHa has an inhibitory effect on the mitogenic action of epidermal growth factor (EGF) in androgen-unresponsive PC-3 cells. The analog reduces PSA gene expression in both hormone-sensitive and -insensitive cells. Interestingly, it counteracts the gene expression induced by androgens in LNCaP cells and by EGF in PC-3 cells.

CONCLUSIONS

These data show that LH-RHa may behave like a negative growth factor, which directly regulates cell growth and PSA gene expression. Moreover, our findings support the idea that growth factors may interfere with the androgen signalling pathway.

Sensitivity of human melanoma cells to oestrogens, tamoxifen and quercetin: is there any relationship with type I and II oestrogen binding site expression?

We investigated the effect of oestrogens, anti-oestrogens and flavonoids on the growth of a human melanoma cell line (SK-Mel-28) and, at the same time, the presence of both type I oestrogen receptors (ERs) and type II oestrogen binding sites (type II EBS) to gain a fuller picture of the relationship between melanoma cell proliferation and receptor status. 17beta-Oestradiol (E2) and the flavonoid quercetin (Q) produced a marked inhibition of proliferation, but only at the highest dose used (10(-5) M) and only when added daily to the medium. Diethylstilboestrol (DES) (10(-5) M) was effective in inhibiting cell growth when the medium was renewed every 3 days and produced a more pronounced reduction when added daily to the medium. Tamoxifen (TAM) inhibited cell proliferation at a dose starting from 10(-7) M when the medium was renewed every 3 days. When added daily to the medium, it did not induce a greater inhibitory effect and it was cytotoxic at 5 x 10(-6) M and 10(-5) M. The antiproliferative effect of E2, DES and Q did not seem to be dependent on their interaction with ERs, which were minimally detected in SK-Mel-28 in both immunocytochemical and biochemical assays. Our model revealed, through a biochemical assay, a large number of type II EBSs which could be involved in the anti-oestrogen action, but this does not exclude the involvement of other mechanisms. Finally, TAM (10(-5) M) appeared to reduce the activity of the DNA repair enzyme O6-alkylguanine-DNA alkyltransferase, an effect that could be interesting from the point of view of the therapeutic efficacy of alkylating agents.

Growth inhibition of fibroblasts from nasal polyps and normal skin by lysine acetylsalicylate

Some authors have shown that lysine acetylsalicylate (LAS) may help prevent nasal polyp relapses. As some anti-inflammatory drugs have been found to regulate cell growth, we investigated the antiproliferative effect of LAS on fibroblasts derived from nasal polyps. Moreover, we studied the effect of LAS on the growth of fibroblasts derived from normal skin to determine whether the response was similar to that obtained in the above-mentioned cells. Fibroblasts were obtained from tissue samples of nasal polyps from two aspirin-tolerant and two aspirin-intolerant patients, and from the normal skin of a healthy donor. The cells were treated with LAS (20-2000 microg/ml of culture medium). Cell growth and viability were evaluated after 3 and 6 days of culture. LAS had a growth-inhibitory effect on cells independently of their derivation. A reduction in cell growth was seen at the concentrations of LAS tested, which correspond to those used in the local treatment of nasal polyposis.

Natural interferon-alpha activity in hormone-sensitive, hormone-resistant and autonomous human breast-cancer cell lines

This study explored the activity of natural interferon-alpha (nIFN-alpha) in regulating cell growth of 6 breast-cancer cell lines. The anti-proliferative effect of the combination nIFN-alpha and tamoxifen (TAM) or medroxyprogesterone acetate (MPA) in CG-5 estrogen-sensitive mammary cancer cells was investigated, and the ability of nIFN-alpha to restore hormone-sensitivity in the MPA-resistant MCF-7 SK sub-line was examined. nIFN-alpha, at concentrations ranging from 10 to 1000 IU/ml, inhibited cell proliferation of all cell lines tested after 3 and 6 days of treatment. In particular, the highest concentration of the drug used was equally effective in hormone-sensitive and in hormone-insensitive cells. A 6-day pretreatment of CG-5 cells with nIFN-alpha, at the above-mentioned doses, sensitized them to the growth-inhibiting activity of subsequent exposure to 10(-7) M TAM or MPA, which resulted in a synergistic effect, and could be explained on the basis of the observed enhancement of estrogen and progesterone receptors due to IFN activity. Conversely, the simultaneous drug combination did not modify the response to the hormone in CG-5 cells. Pre-treatment with nIFN-alpha (from 10 to 1000 IU/ml) restored MPA sensitivity in the MCF-7 SK sub-line, but no modulation of progesterone receptors was seen in this model. The hormone-sensitivity of the parental cell line was not substantially affected by pre-exposure to nIFN-alpha. These data indicate that nIFN-alpha may be potentially useful in enhancing the clinical effectiveness of TAM and MPA and in overcoming hormone resistance.

Interferons inhibit EGF-stimulated cell growth and reduce EGF binding in human breast cancer cells

CG-5 estrogen-sensitive human breast cancer cells contain specific Epidermal Growth Factor receptors (EGF-R, Kd = 0.09-0.17 nM) and respond to the mitogenic effect of EGF. The increase in cell proliferation has been observed starting with very low concentrations of EGF (10-12M) and was statistically significant at all doses. Nevertheless, cell growth stimulation was emphasized when cells were grown under stringent culture conditions. When cells were exposed to 100 IU/ml of natural beta-interferon (n beta-IFN) the binding of EGF to the cell membrane was reduced after 72 hours of treatment, while the exposure of CG-5 cells to 1000 IU/ml of n beta-IFN resulted in an EGF-R reduction which started after 48 hours and became statistically significant after 72-120 hours. If CG-5 cells were treated with 1000 IU/ml of recombinant alpha 2b-interferon (ra2b-IFN) this reduction was observed after 168 hours of exposure to the drug. Both the IFNs abolished EGF-stimulated cell growth. Our results indicate that IFN treatment down-regulates EGF-R in estrogen-sensitive breast cancer cells and suggests that this down-regulation may be involved in the inhibitory action of IFN on cell growth.

Interferon and hormone sensitivity of endocrine-related tumors

Interferons (IFNs) have been shown to enhance both in vitro and in vivo the antiproliferative activity of some hormones and anti-hormones which mainly act via steroid receptors. We discuss some of the mechanisms which could be involved in determining this effect in breast, endometrial and prostatic cancer cells, with a particular emphasis on steroid receptor modulation, reduction of the expression of epidermal growth factor receptors and, finally, down-regulation of some oncogenes. It seems that under appropriate conditions IFN might produce changes in cancer cells that enhance or restore hormone sensitivity. Nevertheless, available clinical data are too few to allow any conclusion to be drawn and this problem merits further investigations.

Effects of interferon-beta on steroid receptors, prostaglandins and enzymatic activities in human endometrial cancer

Steroid receptors, prostaglandin output and enzymatic activities were determined in explants derived from human endometrium exposed to natural interferon-beta (IFN-beta). Receptors and cell metabolism were evaluated before culturing the tissue fragments and after a 3-day treatment with varying concentrations of IFN-beta. Total steroid receptor levels were unchanged when explants were set up, but there was a redistribution of both estrogen and progesterone receptors (ER and PR). A decrease in cytoplasmic receptors corresponded to an increase in receptor molecules within the nucleus. Treatment with low concentrations of IFN-beta caused a significant enhancement (p < 0.05) of ER and PR in neoplastic endometrium. In basal conditions the ratio between prostaglandin F2 alpha (Pgf2 alpha) and prostaglandin E2 (PgE2) was higher in normal than in neoplastic endometrium. The addition of low concentrations of IFN-beta to the culture medium determined a significant increase (p < 0.02) in PgF2 alpha and a parallel increase in the above ratio in neoplastic tissue, while no variation was found in normal endometrium. Analysis of the results concerning the variations in hormone-related enzymatic activities due to IFN-B revealed a significant increase (p < 0.05) in 17 beta-hydroxy-steroid-dehydrogenase (17 beta-HSD) activity. The data presented here indicate that treatment with IFN-beta modifies those biological characteristics of neoplastic cells which are involved in hormone-responsiveness.

Combined effects of estradiol, leuprorelin, tamoxifen and medroxyprogesterone acetate on cell growth and steroid hormone receptors in breast cancer cells

Both tamoxifen and medroxyprogesterone acetate have a direct antitumor effect and are widely used in breast cancer therapy. Luteinizing-hormone-releasing hormone analogs inhibit the growth of breast cancer cells and could represent an alternative treatment for patients affected by breast cancer. Our study was carried out to investigate the effect of leuprorelin (TAP-144) alone or combined with tamoxifen or medroxyprogesterone acetate in human breast cancer cells. Ineffective when used in the absence of estrogens, TAP-144 inhibited the estrogen-stimulated growth of MCF-7, CG-5 and ZR-75-1 cells cultured in medium supplemented with charcoal-treated serum. The growth of estrogen-unresponsive MDA-MB-231 cells was not affected by TAP-144. The combination of TAP-144 with tamoxifen in CG-5 cells did not determine any enhancement of inhibition of cell growth, whereas in both CG-5 and MCF-7 cells, when 1 microM TAP-144 was associated with 0.1 microM medroxyprogesterone acetate, cell growth inhibition was increased, resulting in a subadditive effect. Progesterone receptor levels of CG-5 cells were significantly increased by TAP-144 in the presence of 17 beta-estradiol with respect to those present in control and 17 beta-estradiol-treated cells.

Direct antiproliferative effect of triptorelin on human breast cancer cells

We investigated the effect of Triptorelin (Decapeptyl, DEC) alone or combined with Tamoxifen (TAM) or Medroxyprogesterone acetate (MPA) in human breast cancer cells. DEC did not affect the growth of estrogen-insensitive MDA-MB-231 cells, while it inhibited the estrogen-stimulated proliferation of MCF-7 and CG-5 cells. No amplification of growth inhibition induced by TAM or MPA was determined by DEC. Progesterone receptor levels of CG-5 cells were significantly enhanced by DEC in the presence of 17 beta-estradiol (E2) with respect to those in control and E2-treated cells.

Androgen receptors and hormone sensitivity of a human prostatic cancer cell line (PC-3) are modulated by natural beta-interferon

Androgen receptors are expressed at a low level in the cell line PC-3, which does not respond to either androgens or antiandrogens. If these cells are exposed to natural beta-interferon (beta-IFN) a reduction in cell growth and an increase in androgen receptors, evaluated by both biochemical and immunocytochemical techniques, occur. This increase seems not to be related to a selective block of PC-3 in any phase of the cell cycle. Pretreatment with beta-IFN determines in PC-3 cells a partial responsiveness to the androgen dihydrotestosterone as reflected by the increase in cell number. Moreover, the antiandrogen hydroxyflutamide shows agonistic properties by increasing the cell number of PC-3 cells pre-exposed to beta-IFN. When the antiandrogen is tested in combination with interferon, it produces a reduction in the beta-IFN-induced inhibition of cell growth. It is not known whether these unexpected effects are due to the increase in androgen receptors or to other mechanisms.

Natural interferon-beta treatment and steroid hormone receptors in primary endometrial cancer

Forty-three patients with primary endometrial carcinoma were treated with natural interferon-beta (IFN-beta) at two different dose levels (2 x 10(6) IU or 6 x 10(6) IU im 3 times/week for 1 week). IFN-beta increased receptors for estrogens (ER) and progesterone (PR) in a high percentage of the 40 evaluable patients, without modifying the receptor affinity. The ER and PR enhancement, which was simultaneous in at least 50% of patients, and the increase of over 100 fmol/mg protein observed in some cases suggest that IFN-beta exerts a profound influence on receptor expression and, probably, on the hormone sensitivity of the tumor.

Steroid receptor enhancement by natural interferon-beta in advanced breast cancer

In the current study we investigated the effect of two different doses of natural interferon-beta (IFN-beta) on steroid hormone receptors in 45 patients with advanced breast cancer. IFN-beta seems to regulate the receptor mechanisms, inducing in cutaneous metastases an increase of oestrogen and progesterone receptors. Moreover, using IFN-beta and tamoxifen as a combined therapy in 23 receptor-positive patients, no negative interference of the two drugs was observed and no relevant side-effects due to the treatment were noticed. The modulation of steroid receptor content by IFN-beta in advanced breast cancer might represent an interesting way to ameliorate the clinical responsiveness to anti-oestrogens.

Effect of natural beta-interferon on estrogen receptor mRNA of breast cancer cells

We have demonstrated that natural beta-interferon (beta-IFN) enhances estrogen receptor (ER) mRNA of a human breast cancer cell line, CG-5. Cells were sensitive to the effect of beta-IFN at concentrations ranging from 10 to 100 IU/ml. The increase of ER mRNA was seen after 48 hr of treatment in at least three separate experiments. Our results are in agreement with the previously observed enhancement of receptor protein. In addition, they suggest that the IFN-induced promotion of the antiproliferative activity of drugs which act via ER may be due, in part, to increased receptor synthesis.

Recombinant interferon-alpha 2b affects proliferation, steroid receptors and sensitivity to tamoxifen of cultured breast cancer cells (CG-5)

Exposure of CG-5 human breast cancer cells to recombinant interferon (IFN)-alpha 2b results in a significative inhibition of cell proliferation; this is observed when cells are cultured in their standard conditions and is not modified if serum concentration present in the culture medium is lowered. Estrogen receptors are increased in CG-5 cells following a 5 day treatment with concentrations of IFN-alpha 2b ranging from 10 to 1000 IU/ml of culture medium. Progesterone receptors seem to be more influenced by a longer treatment with the drug (7 days). The Kd of both receptors is not modified by the exposure of cells to IFN-alpha 2b. Finally, the antiproliferative effect of tamoxifen on CG-5 cells is amplified by the simultaneous addition to culture medium of IFN-alpha 2b even at very low concentrations.

Antitumor effect of lonidamine alone or combined with tamoxifen or medroxyprogesterone acetate in breast cancer cells

The effect of Lonidamine (LND) alone or combined with the antiestrogen Tamoxifen (TAM) or Medroxyprogesterone acetate (MPA) on cell proliferation and steroid hormone receptor content of a human estrogen sensitive breast cancer cell line was investigated. LND has a direct growth inhibitory action, even if used at relatively low concentrations (10(-7) M), and shows the maximum effect at 10(-4) M. The combination of LND with the antiestrogen does not produce a potentiation of the TAM-induced reduction of cell number, while the association of the drug with MPA seems more effective with respect to MPA alone, at least at certain concentrations. The negative interference observed between LND and TAM may be due to the LND-induced decrease of estrogen receptor levels.

Natural beta-interferon and androgen receptors in prostatic cancer cells

Both PC-3 and DU-145 cell lines are androgen-insensitive, but, in our experience, they contain androgen receptors (AR). Treatment of these cells with natural beta-interferon at a concentration of 1,000 IU/ml of culture medium determines an increase of AR (evaluated by a whole-cell assay), statistically significant with respect to control. Androgen unresponsiveness of our cells could be due to an AR level which is lower than that present in hormone-sensitive prostatic cancer cell lines, such as LNCaP cells. For this reason, interferon-promoted AR increase merits further investigation, even if other defects in receptor mechanism, responsible for hormone insensitivity, cannot be excluded.

Antiproliferative effect of lonidamine on a human glioblastoma multiforme cell line

Recent data from phase II trials have shown that lonidamine (LND) is effective in the treatment of tumors of various histogenesis, including gliomas. In the present work, we tested the antiproliferative effect of LND on a human glioblastoma cell line (LI) in different culture conditions. When LI are cultured in their standard conditions, a reduction of cell growth is seen after 3 days of treatment with 10(-4) M LND. It reaches 70% with respect to control after 6 days and is statistically significant. LND is ineffective at the other concentrations tested. In more stringent culture conditions, 10(-4) M LND determines a higher inhibition of cell proliferation both after 3 and 6 days of exposure, while other doses of LND are unable to affect cell growth.

Hormonal modulation of brain tumour growth: a cell culture study

Tissue samples derived from two neuroepithelial tumours and five meningiomas were obtained at surgery from seven patients and cultured in order to study the effect of dexamethasone (DEX) and testosterone acetate (TA) on cell proliferation. Glucocorticoid and androgen receptors (GR, AR) were determined both on tissue samples (7 cases) and on five out of the seven cell cultures obtained by tumours. GR and AR were present respectively in 5 and in 4 out of the tumour specimens assayed and in 4/5 and 2/3 of the tested cell cultures. DEX activity on cell growth was tested on six cell cultures. Four of them showed a significant growth inhibition at the highest drug concentration. On the contrary, a significant growth stimulation was observed in four out of the five cultures, where GR were present, using low hormone concentrations. Treatment with pharmacological doses of TA caused a significant cytotoxicity in all the tested cultures. Low TA concentrations inhibited cell growth in one out of the two cell cultures which contained AR, but were ineffective in cultures lacking AR. Our preliminary results suggest a possible role in growth regulation by DEX and TA in intracranial tumours, on the basis of the presence of specific hormone receptors.

In vitro effects of beta-interferon on steroid receptors and prostaglandin output in human endometrial adenocarcinoma

The effect of natural beta-interferon (beta-IFN) on steroid receptor levels and output of prostaglandins (PGs) was investigated in human endometrial cancer. beta-IFN determines in endometrial adenocarcinoma explants an increase of cytosolic estradiol (ER) and progesterone (PR) receptors at concentrations ranging from 10 to 1000 IU/ml of culture medium. Only cases in which there was an enhancement of at least 50% with respect to control values were considered. Low concentrations of beta-IFN (10 IU/ml of culture medium) produce an enhancement of ER in 60% and of PR in 42% of cases, while higher concentrations of beta-IFN (1000 IU/ml of culture medium) produce an enhancement of ER in 32%, and of PR in 82% of cases. Since PGs are involved in proliferation control in a large variety of tumors, we evaluated the ratio between PGF2-alpha and PGE2 levels in culture medium. This ratio increased, in our experimental model, after treatment with 10 and 1000 IU/ml of beta-IFN in 38% and 58% of cases respectively. Our data suggest that beta-IFN could affect cellular hormone sensitivity through a modification of ER and PR and it can also determine a variation of PG output in human endometrial cancer.