Strain-dependent and distinctive T-cell responses to HIV antigens following immunisation of mice with differing chimpanzee adenovirus vaccine vectors.

In vivo vaccination studies are conventionally conducted in a single mouse strain with results, only reflecting responses to a single immunogenetic background. We decided to examine the immune response to an HIV transgene (gag, pol and nef fusion protein) in 3 strains of mice (CBA, C57BL/6 and BALB/c) to determine the spectrum of responses and in addition to determine whether the serotype of the adenoviral vector used (ChAd3 and ChAd63) impacted the outcome of response. Our results demonstrated that all three strains of mice responded to the transgene and that the magnitude of responses were different between the strains. The C57BL/6 strain showed the lowest range of responses compared to the other strains and, very few responses were seen to the same peptide pool in all three strains of mice. In CBA and BALB/c mice there were significant differences in IFNγ production dependent on the adenoviral vector used. Our results suggest that employing a single strain of mouse may underestimate the efficacy and efficiency of vaccine products.

Analysis of T cell responses to chimpanzee adenovirus vectors encoding HIV gag-pol-nef antigen.

Adenoviruses have been shown to be both immunogenic and efficient at presenting HIV proteins but recent trials have suggested that they may play a role in increasing the risk of HIV acquisition. This risk may be associated with the presence of pre-existing immunity to the viral vectors. Chimpanzee adenoviruses (chAd) have low seroprevalence in human populations and so reduce this risk. ChAd3 and chAd63 were used to deliver an HIV gag, pol and nef transgene. ELISpot analysis of T cell responses in mice showed that both chAd vectors were able to induce an immune response to Gag and Pol peptides but that only the chAd3 vector induced responses to Nef peptides. Although the route of injection did not influence the magnitude of immune responses to either chAd vector, the dose of vector did. Taken together these results demonstrate that chimpanzee adenoviruses are suitable vector candidates for the delivery of HIV proteins and could be used for an HIV vaccine and furthermore the chAd3 vector produces a broader response to the HIV transgene.

Differential expression of the ccn3 (nov) proto-oncogene in human prostate cell lines and tissues.

AIMS: To investigate the expression of the human ccn3 (hccn3; nov) proto-oncogene, a member of the CCN family of proteins, in prostate epithelial cells and prostate tissue samples. METHODS: Normal adult prostate luminal epithelial cells immortalised by SV40 large T (PNT1A and PNT1B), metastatic tumours (LNCaP, DU-145, and PC-3), and prostate tissue samples from patients with benign prostatic hyperplasia (BPH) and prostatic adenocarcinoma were used. hccn3 (nov) mRNA was measured by the reverse transcription polymerase chain reaction (RT-PCR) and hCCN3 (NOV) protein expression was determined by immunochemistry. RESULTS: hccn3 (nov) RNA values were higher in PC-3 cells than in the other prostate cell lines. The immortalised normal cell lines either did not express hccn3 (nov) RNA (PNT1B) or expressed very low amounts (PNT1A). BPH samples expressed variable amounts of hccn3 (nov) RNA. With the use of immunocytochemistry, all cell lines except PNT1A and PNT1B were shown to contain hCCN3 (NOV) protein. hCCN3 (NOV) was localised mainly in the epithelial compartment of BPH and adenocarcinoma samples, and there was evidence of luminal secretion. CONCLUSION: The overexpression of hccn3 (nov) RNA in cancer cell lines compared with other cell lines and its epithelial localisation in human prostate samples are consistent with a role for hCCN3 (NOV) in prostatic tumorigenesis.

Insulin-like Growth Factor (IGF) Network and Prostate Pathologies.

The Insulin-like Growth Factor (IGF) network in prostate tissue represents a key element in normal and tumour growth. It can provide us with new markers for prognosis or diagnosis and targets for treatment of prostate diseases. This short review introduces the IGF network in general and in the prostate gland, summarises the modifications observed in tumours and discusses the importance of a new family of low affinity IGF-binding proteins. Further studies on the IGF network will enrich our understanding of prostate tumourigenesis and its control and therefore provide new therapeutics to master the IGF network

Estramustine resistance correlates with tau over-expression in human prostatic carcinoma cells.

Estramustine (EM) is an anti-microtubule drug used in the treatment of hormone-refractory advanced prostate cancer. Since microtubules are the targets for EM cytotoxicity, we investigated the effects of EM on the microtubule-associated protein tau to determine what role it may play in drug resistance. We have compared tau expression in human prostate cancer cells (DU145) and an EM-resistant derived cell line (E4). Reverse transcriptase polymerase chain reaction has established that tau is expressed in both cell lines but increased 1.9-fold in E4 compared with DU145 cells. This result was confirmed at the protein level by Western blotting. Tau is a phosphoprotein, most of its reported phosphorylation sites being serine or threonine residues. We have shown, however, that tau is also phosphorylated at tyrosine residues in DU145 cells and that the phosphotyrosine level of tau is significantly increased in E4 cells. Moreover, DU145 cells exposed to short term micromolar drug concentrations enter a phase of microtubule depolymerization, display an increased level of tau phosphorylation and follow a pattern similar to that observed in EM-resistant E4 cells. EM is therefore able to induce a very rapid change in the posttranslational state of tau. Our results show that the acquisition of EM resistance in E4 cells, which is accompanied by changes at the tubulin level, is also associated with important changes in tau expression and phosphorylation.

Association of estramustine resistance in human prostatic carcinoma cells with modified patterns of tubulin expression.

Estramustine (EM) is an antimicrotubule drug used in the treatment of hormone refractory advanced prostate cancer. To investigate the mechanism of resistance to EM, we compared its effects on human prostate cancer cells (DU145) and an estramustine-resistant derived cell line (E4). Immunofluorescence demonstrated that EM caused depolymerization of microtubules and blocked cells in mitosis in DU145 cells, with less effect in E4 cells. Using tubulin isotype-specific antibodies, a threefold increase in betaIII and approximately twofold increase in betaI + II isotype in E4 cells compared to DU145 cells were observed. A most interesting observation concerned an increase in the posttranslational modification of alpha-tubulin of both polyglutamylation and acetylation in the E4 cells. Significant to this observation, using direct EM photoaffinity labeling of tubulin, drug binding to the most acidic posttranslationally modified forms of alpha-tubulin was shown to be minimal. Taken together, these results indicate that the modification of the tubulin expression pattern may be responsible for estramustine resistance by both lowering the amount of drug bound to microtubules and inducing more stable microtubules.

Lipid signals detected by NMR proton spectroscopy of whole cells are not correlated to lipid droplets evidenced by the Nile red staining.

Nile red staining was used to detect lipid droplets in the K562 cell line sensitive and resistant to adriamycin and their resistance-reversing counterparts. The staining obtained was compared to the intensity of lipid signal detected in proton nuclear magnetic resonance spectra. From the four cell lines used, a lack of correlation was observed between the NMR signal and the Nile red staining. For example, the sensitive K562 cells, with the highest level of NMR signals, showed only few cells containing lipid droplets. We concluded that is lipid droplets can participate to lipid signal in NMR spectra, other lipids must also participate to these resonance.

The somatostatin receptor subtype 2 is expressed in normal and tumoral human tissues70.

Somatostatin (SS) can inhibit growth hormone (GH) secretion from the pituitary and tumor cell proliferation via membrane-bound receptors (SST). Five SST subtypes have been cloned and can be discriminated by specific peptides. In order to evaluate the human tissue distribution of the SSTs, we first used the cross-linking assay with the 125I-SS-14. A cross-linked complex of 57 kDa was detected in a majority (76%) of the surgical biopsies of normal and tumoral tissues examined (N = 222) and in all tested cell lines (N = 20). However, in regard to the organs, the incidence varied from 33% (epiploon metastases) to 100% (colorectal adenocarcinoma, prostate). Additional, minor SS-14 cross-linked complexes were detected in a few samples, suggesting the simultaneous existence of other SST subtypes. In tumor cell lines, the 57-kDa complex was reduced by the SST2-selective SS analogs BIM23014, BIM23060, and BIM23068, and by SS-14 but not by the non-SST2-selective BIM23052 and BIM23056. Its pharmacological profile therefore corresponded to SST2. Northern blot analysis showed one 2.5-kb human SST2 mRNA in these cell lines. We demonstrate that SST2 is detectable in normal and tumoral human tissues and thus represents an SST subtype target for the development of more specific SS analogs.

Value of the preoperative detection of prostate-specific-antigen-positive circulating cells by nested RT-PCR in patients submitted to radical prostatectomy.

OBJECTIVE: To assess the value of the detection of circulating prostate cells [prostate-specific antigen (PSA) positive] by reverse-transcriptase nested polymerase chain reaction (nested RT-PCR) to improve the staging of clinically localized prostate cancer. METHODS: Nested PCR was performed on blood samples of 29 patients submitted to radical prostatectomy for clinically localized (T1-T2) prostate cancer. Nine patients with various benign urologic diseases comprised the negative control group. Incubation was for 25 cycles for each PCR, using beta 2-microglobulin to test the integrity of RNA samples. Each sample was tested in quadruplicate and analyzed by agarose gel electrophoresis, blotted and hybridized with specific internal primers. Nested PCR results were compared with the pT stage of the prostate specimen, processed according to the Stanford method. RESULTS: In 6 out of 29 patients (20.7%) with clinically localized prostate cancer, circulating prostate cells were detected by nested PCR. There was no relationship between pathologic stage and RT-PCR results. Eleven out of 14 pT2 patients (78.6%) were PCR negative and only 3 out of 15 pT3 patients (20%) were PCR positive. All control samples were PCR negative. CONCLUSIONS: In selected patients with T1-T2 prostate cancer, there was no relationship between pathologic stage and the presence of circulating PSA-positive cells detected by nested PCR. However, in 20.7% of patients with clinically localized prostate cancer, circulating prostate cancer cells were detected. A further follow-up based on PSA is necessary to clarify the clinical relevance of this biologic anomaly.

Stromal cells from human benign prostate hyperplasia produce a growth-inhibitory factor for LNCaP prostate cancer cells, identified as interleukin-6.

To understand specific interactions between stromal cells and epithelial cells in benign prostatic hyperplasia (BPH) and prostatic adenocarcinoma, we developed stromal-cell cultures from normal human prostate (PNX) and BPH (BH101), composed of fibroblasts and myofibroblasts. Their role in epithelial-cell growth was studied using the established cancer cell lines LNCaP, PC3 and DU145 and an SV40 large T-immortalized normal epithelial-cell line, PNT1A, in double-diffusion co-culture chambers. PNT1A was stimulated by PNX (x1.6) and more strongly by BH101 stromal cells (x2.7). Conversely, LNCaP growth decreased by 50% in the presence of BH101 stromal cells (stromal/epithelial ratio: 10). A BH101-conditioned medium (CM), obtained in serum-free conditions, induced 90% inhibition of [3H]thymidine incorporation of the LNCaP androgen-sensitive cell line. Two other androgen-independent prostate cancer cell lines were either insensitive to BH101 CM (PC3) or slightly inhibited (40% for DU145). BH101 produced large amounts of IL-1beta, IL-6 and IL-8. HPLC gel filtration enabled separation of an inhibitory fraction which contained IL-6. IL-6 was demonstrated to be responsible for the strong inhibitory effect since an IL-6-neutralizing antibody abolished this inhibition, which was reproduced by human recombinant IL-6. Recombinant IL-6 growth inhibition was observed only on LNCaP prostate cancer androgen-sensitive cells.

Proton nuclear magnetic resonance spectroscopy reveals cellular lipids involved in resistance to adriamycin and taxol by the K562 leukemia cell line.

Proton nuclear magnetic resonance spectroscopy was performed on whole cells to study lipids and metabolites in Adriamycin- and Taxol-resistant K562 cells expressing multidrug resistance (MDR) and their sensitive counterparts. With one-dimensional spectra, both resistant cell lines showed lower fatty acid methylene:methyl ratios and higher choline:methyl ratios than sensitive cells. Using two-dimensional COSY spectra, a decrease in the glutamine content was evidenced in resistant cells. When these cells were maintained in culture medium without the drug, the fatty acid signals were partially recovered. Adriamycin-resistant K562 cells were also treated for 4 days with a high dose of verapamil, a MDR-reversing agent. The nuclear magnetic resonance spectra of verapamil-treated cells also showed partial recovery of fatty acid signals. These results could be paralleled with the reversion of the resistant phenotype, as evidenced by measuring the inhibiting concentration of Adriamycin and vinblastine in K562adr cells cultured without the drug or after short-term exposure to verapamil. Conversely, P-glycoprotein and mRNA expression and DNA amplification of the mdr gene were not modified when compared to resistant cells, suggesting that the MDR phenotype could be partially reversed independently of the mdr gene amplification and expression. These results demonstrate the role of lipids in the resistance phenomenon.

Somatostatin receptors in prostate tissues and derived cell cultures, and the in vitro growth inhibitory effect of BIM-23014 analog.

We investigated somatostatin receptors (SSTRs) in surgical specimens of prostate cancer and benign prostate hyperplasia (BPH), a normal immortalized epithelial cell line (PNT1), epithelial cancer cell lines, and stromal cells in short-term culture derived from normal and BPH biopsies. Cross-linking studies with 125I-Tyr11-SRIF-14 (125I-SRIF) and the SRIF analog 125I-BIM-23104 identified one major 57-kDa band both in surgical specimens and in epithelial and stromal cells cultures. In membrane-enriched fractions and whole stromal cells from a normal prostate and from one BPH, a single type of SSTR was characterized (Kd = 6.10(-9) and 10(-8) M, respectively, Bmax = 1.6 pmol per mg of proteins). mRNA for SSTR1 was detected in all epithelial and stromal cells tested except for PNT1, while SSTR2 mRNA was detected in one BPH stromal cell culture. BIM-23104 had no effect on the in vitro growth of the epithelial cells tested. Conversely, 10(-10) M BIM-23104 induced >50% growth inhibition of stromal cells after 6 days in culture. These results may have implications for therapeutic strategies using SRIF analogs in BPH and prostate cancer.

[Peptide growth factors in the prostate]. / Les facteurs de croissance peptidiques de la prostate.

Growth and development of the prostate depend on androgen action and other factors. Androgens act directly by specific nuclear receptors and induce or control many effects mediated by peptide growth factors on both epithelial and stromal cells. The major important peptide growth factors detected in the prostate are Fibroblast Growth Factors, Transforming Growth Factors, and Epidermal Growth Factor. These factors are not prostate specific. They are produced by epithelial or stromal cells and regulate the growth of these two cell compartments through autocrine or paracrine pathways. Overproduction of these factors or modification in affinity or number of cell receptors may participate in the two main prostatic pathologies: benign hyperplasia or adenocarcinoma. Recently, other factors have been evidenced in the prostate: Interleukine 6, Nerve Growth Factor or Insulin-like Growth factors. The study of the localization and the effects of these factors may be crucial to understand the prostatic development and diseases and may suggest new targets for therapy.

[Prostatic growth factors and benign hypertrophy of the prostate. Current knowledge and perspectives]. / Facteurs de croissance prostatiques et hypertrophie bénigne de la prostate. Etat des connaissances actuelles et perspectives.

The importance of growth factors in prostatic regulation has been demonstrated for several years. These "prostatic" growth factors are ubiquitous polypeptides which are not specific to the prostate. To date, three principal families of growth factors appear to be potentially involved in the development of benign prostatic hypertrophy: Epidermal Growth Factor (EGF), Fibroblast Growth Factor (FGF), Transforming Growth Factor beta (TGF beta). The FGF and TGF beta families probably play a central role in the pathogenesis of benign prostatic hypertrophy. A better definition of the respective roles of growth factors and androgens in the control of prostatic growth opens up prospects for the future in the field of basic treatment of benign prostatic hypertrophy.

Cell and membrane lipid analysis by proton magnetic resonance spectroscopy in five breast cancer cell lines.

The lipid composition of five human breast cancer cell lines (MCF-7, T47D, ZR-75-1, SKBR3 and MDA-MB231) was assessed by proton magnetic resonance spectroscopy (MRS) in whole cells and membrane-enriched fractions. The proportions of the three main lipid resonances in 1D spectra were different for each cell line. These resonances included mobile methyl and methylene functions from fatty acids of triglycerides and phospholipids and N-trimethyl from choline of phospholipids. T47D and ZR-75-1 cells presented a high methylene/methyl ratio (6.02 +/- 0.35 and 6.28 +/- 0.90). This ratio was significantly lower for SKBR3, MCF-7 and MDA-MB231 cells (2.76 +/- 0.22, 2.27 +/- 0.57 and 1.39 +/- 0.39). The N-trimethyl/methyl ratio was high for MDA-MB231 and SKBR3 cells (1.38 +/- 0.54 and 0.86 +/- 0.32), but lower for MCF-7, T47D and ZR-75-1 cells (0.49 +/- 0.11, 0.16 +/- 0.07 and 0.07 +/- 0.03). 2D COSY spectra confirmed these different proportions in mobile lipids. From 1D spectra obtained on membrane preparations, T47D and ZR-75-1 were the only cell lines to retain a signal from mobile methylene functions. These differences might be related to the heterogeneity found for several parameters of these cells (tumorigenicity, growth rate, hormone receptors); an extended number of cases from fresh samples might enable clinical correlations.

[Lipid profiles of breast cancer cell lines: proton nuclear magnetic resonance spectroscopy]. / Profils lipidiques de lignées de cancer du sein: spectrométrie par résonance magnétique nucléaire du proton.

Nuclear magnetic resonance spectroscopy was performed on breast cancer cell lines MCF-7, MDA-MB231 and T47D. Proton spectra showed discrepancies of lipid quantity in the different lines. The high resolution lines of lipids were not as intense in the membrane preparations. These results show the potential of NMR spectroscopy to study the involvement of membrane lipids in proliferation, metastasis or drug resistance process.