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P de Cremoux

Publications and source records attributed to P de Cremoux.

At least 19 recordsLinked to original sources
PubMed2007

Potentiation of antitumour activity of docetaxel by combination with trastuzumab in a human prostate cancer xenograft model and underlying mechanisms.

Antitumour activity of docetaxel (Taxotere) in hormone-dependent (HD) and hormone-independent (HID) prostate cancer PAC120 xenograft model was previously reported, and its level was associated with HER2 protein expression. In the present study, we evaluate the antitumour effects of docetaxel combined with trastuzumab (Herceptin), an anti-HER2 antibody. Although trastuzumab alone had no effect on tumour growth, it potentiated the antitumour activity of docetaxel in HD tumours and more strongly in HID variants. Using the HID28 variant, we show that docetaxel treatment of tumour-bearing mice induces an increased HER2 mRNA expression of the tyrosine kinase receptor of 25-fold 24 h after docetaxel treatment, while HER2 protein and p-AKT decreased. This was followed by an increase of HER2 protein 3 days (two-fold) after docetaxel treatment and by a strong HER2 release in the serum of treated mice; expression of phospho-ERK, p27, BCL2 and HSP70 concomitantly increased. Similar molecular alterations were induced by docetaxel plus trastuzumab combination, except for that there was a transient and complete disappearance of AR and HSP90 proteins 24 h after treatment. We show that in addition to its known effects on tubulin and mitotic spindles, docetaxel induces complex signalisation pathway mechanisms in surviving cells, including HER2, which can be pharmacologically targeted. This study suggests that the docetaxel/trastuzumab combination may prove an effective therapeutic approach for HER2-expressing hormone-refractory prostate cancer.

Antibodies, Monoclonal↗
PubMed2006

Estrogen receptors evolution in neoadjuvant aromatase inhibitor (AI) therapy for breast cancer in elderly women: stability of hormonal receptor expression during treatment.

UNLABELLED: In France, 20% of breast cancers occur in women over the age of 70 and 10% in women over the age of 80. As these women are not included in screening programs, breast cancer is often diagnosed later, at the stage of a large tumor. PURPOSE: To analyze clinical response, possibilities of conservative treatment and course of hormonal receptors in patients receiving neoadjuvant aromatase inhibitor (AI) therapy for at least 6 months. PATIENTS AND METHODS: There were 75 patients, with a mean age of 75 +/- 8 years (range, 58-91 years) received AI for 6 months after the diagnosis of invasive breast cancer with positive hormonal receptors. Clinical and radiologic tumor reduction, the number of conservative treatments and the course of estrogens receptor-labeled cells were determined for each patient. RESULTS: All but 1 of these patients obtained clinical reduction of their tumor. Of these, 86% patients received conservative treatment. In the majority of patients, estrogen receptor (ER) level did not vary between the initial assay and analysis of the operative specimen. DISCUSSION AND CONCLUSION: Aromatase inhibitors are effective as neoadjuvant therapy in ER positive elderly patients with large tumors, as is tamoxifen. Changes in hormone receptor expression during treatment do not predict clinical response. In our experience, neoadjuvant AI therapy should be administered for at least 6 months to optimize clinical response before deciding upon surgery. Discrepancy observed in the literature could be explained by the duration of the treatment.

Aged↗
PubMed2004

Inter-laboratory quality control for hormone-dependent gene expression in human breast tumors using real-time reverse transcription-polymerase chain reaction.

Quantitative reverse transcription-polymerase chain reaction (RT-PCR) used to detect minor changes in specific mRNA concentrations may be associated with poor reproducibility. Stringent quality control is therefore essential at each step of the protocol, including the PCR procedure. We performed inter-laboratory quality control of quantitative PCR between two independent laboratories, using in-house RT-PCR assays on a series of hormone-related target genes in a retrospective consecutive series of 79 breast tumors. Total RNA was reverse transcribed in a single center. Calibration curves were performed for five target genes (estrogen receptor (ER)alpha, ERbeta, progesterone receptor (PR), CYP19 (aromatase) and Ki 67) and for two reference genes (human acidic ribosomal phosphoprotein PO (RPLPO) and TATA box-binding protein (TBP)). Amplification efficiencies of the calibrator were determined for each run and used to calculate mRNA expression. Correlation coefficients were evaluated for each target and each reference gene. A good correlation was observed for all target and reference genes in both centers using their own protocols and kits (P < 0.0001). The correlation coefficients ranged from 0.90 to 0.98 for the various target genes in the two centers. A good correlation was observed between the level of expression of the ERalpha and the PR transcripts (P < 0.001). A weak inverse correlation was observed in both centers between ERalpha and ERbeta levels, but only when TBP was the reference gene. No other correlation was observed with other parameters. Real-time PCR assays allow convenient quantification of target mRNA transcripts and quantification of target-derived nucleic acids in clinical specimens. This study addresses the importance of inter-laboratory quality controls for the use of a panel of real-time PCR assays devoted to clinical samples and protocols and to ensure their appropriate accuracy. This can also facilitate exchanges and multicenter comparison of data.

Aromatase↗
PubMed2003

Validation of real-time RT-PCR for analysis of human breast cancer cell lines resistant or sensitive to treatment with antiestrogens.

Using a quantitative real-time RT-PCR technique we have compared the expression of a number of genes in two different human breast cancer model systems for development of acquired resistance to antiestrogens. The model system developed at the Danish Cancer Society comprises the cell lines MCF-7, MCF-7/TAMR-1, MCF-7/182R-6 and MCF-7/182R-7, and the model system developed at the Lombardi Cancer Research Center consists of the cell lines MCF-7/LCC1, MCF-7/LCC2 and MCF-7/LCC9. The findings on the well-known parameters estrogen receptor (ER)alpha, progesterone receptor (PR) and epidermal growth factor receptor (EGFR) are in good agreement with previous reports, thus documenting the usefulness of the real-time RT-PCR technique for multiparametric RNA analysis. The gene expression levels in the two model systems were found to be quite similar in relation to ERalpha, AIB1 (amplified in breast cancer-1), breast cancer antiestrogen resistance gene 1 (BCAR1) and ErbB-2 mRNA expression, whereas significant differences were observed on the expression of ERbeta, multidrug resistance gene 1 (MDR1), PR and EGFR. Furthermore, the presented data suggest that ERbeta, AIB1, BCAR1, CYP19 and MDR1 are unlikely to be causally involved in development of antiestrogen resistance in these breast cancer cell lines.

Aromatase↗
PubMed2001

Cost-effectiveness of monolayers and human papillomavirus testing compared to that of conventional Papanicolaou smears for cervical cancer screening: protocol of the study of the French Society of Clinical Cytology.

The French Society of Clinical Cytology is conducting a study to compare the cost-effectiveness of monolayers and human papillomavirus (HPV) testing with that of conventional Papanicolaou (Pap) smears for cervical cancer screening. The protocol of this study is presented. It includes 3,000 women who will be evaluated by the three methods (conventional Pap smears, or monolayers with or without HPV testing) and by the reference method: colposcopy followed, in cases with abnormalities, by cervical biopsy. Efficacy or performance of the methods will be compared on the basis of sensitivity. Cost comparisons and cost-effectiveness modeling will be based on the costs associated with methods themselves and also the costs of "false positives." This will require specific collection of data concerning the costs of the three methods, as these costs have not previously been accurately documented. Patient recruiting and data collection started in September 1999 and will be complete in June 2000. The first results are expected to be available in spring 2001.

Cost-Benefit Analysis↗
PubMed2000

Detection of MUC1-expressing mammary carcinoma cells in the peripheral blood of breast cancer patients by real-time polymerase chain reaction.

We have prospectively analyzed blood samples of 122 patients with breast disease for the presence of circulating expressing MUC1 cells before and after treatment. Among them, 28 patients had histologically confirmed benign breast disease (group 1), 34 patients had operable breast cancer (group 2), and 60 patients had advanced breast cancer (group 3). Circulating epithelial cells were isolated with BerEP4-coated immunomagnetic beads. Total RNA was extracted and reverse transcribed before analysis by real-time PCR of a MUC1-specific cDNA sequence. The sensitivity of the reverse transcription-PCR tested with blood spiked with MCF7 cells was one cell in 5 ml of blood. The immunomagnetic separation step was mandatory to obtain the maximum specificity. Control samples from healthy donors never displayed cycle threshold (Ct) values for MUC1 lower than 38. Circulating cells (Ct, <38) were detected in 3 of 28 (11%) cases in group 1, in 8 of 34 (24%) cases in group 2, and in 27 of 60 cases (45%) in group 3. A semiquantitative estimate of blood-borne cells could be derived from the Ct value when below 32 (the lowest was 28) or by the number of positive aliquots of the same blood sample. Thus, immunomagnetic separation, followed by MUC1-specific RT-PCR, allows the semiquantitative detection of circulating mammary cells. A significant correlation between the presence of MUC1-positive cells and the group of breast tumors was observed. The clinical significance of blood-borne cells in breast cancer, especially at the operable stage, may be investigated by following these patients.

Adult↗
PubMed1999

Quantitative PCR analysis of c-erb B-2 (HER2/neu) gene amplification and comparison with p185(HER2/neu) protein expression in breast cancer drill biopsies.

A PCR assay using capillary electrophoresis was designed for the detection of c-erbB-2 gene amplification in alcohol-formalin-acetic acid (AFA)-fixed, paraffin-embedded biopsies from 81 consecutive breast tumors. c-erbB-2 expression was analyzed in the same samples using immuno-histochemistry (IHC). In the competitive PCR assay, a single pTag plasmid containing a 4-nucleotide (nt)-deleted copy of a 124-nt sequence of c-erbB-2 and a 4-nt-deleted copy of a 120-nt sequence of GAPDH was co-amplified with genomic DNA extracted from 3 10-micrometer-thick tissue sections of the tumor biopsy. The percentage of tumor cells in the biopsy specimen and the percentage of tumor cells stained with the membrane anti-c-erbB-2 monoclonal antibody CB11 were recorded by a single pathologist on 2 consecutive sections. Among 81 consecutive tumor biopsies assayed by PCR, 21 (26%) displayed unequivocal c-erbB-2 amplification (actual gene copy number, AGCN > 4), 47 (58%) displayed no c-erbB-2 amplification (AGCN </= 2) and 7 (9%) could not be analyzed due to an insufficient amount of DNA. Six samples (7%) were considered inconclusive since the percentage of tumor cells was <20%. Analysis of c-erbB-2 expression by IHC showed that among the 21 amplified specimens 15 displayed strong staining, while all non-amplified samples (47) displayed no or only weak staining. The concordance of the 2 techniques was 91%. We conclude that c-erbB-2 gene amplification can be accurately quantitated by competitive PCR performed on small, fixed and embedded tumor samples.

Adenocarcinoma↗
PubMed1998

Is p53 a protein that predicts the response to chemotherapy in node negative breast cancer?

The role of p53 in modulating apoptosis has suggested that it may affect efficacy of anti cancer agents. For this reason, we have evaluated p53 alterations in 282 consecutive patients with infiltrating node-negative breast cancer who underwent primary surgery and were randomized either to CMF (Cyclophosphamide 400 mg/m2, Fluorouracil 400 mg/m2, and Methotrexate 40 mg/m2) or control arm (no adjuvant therapy) from 1980 to 1989. p53 alterations were analyzed by immunohistochemistry using DO7 MoAb, revealed by immunoperoxidase technique, and quantitated in term of percentage of positive cells. We observed a positive staining in 24% of the tumors. Among them, 10% had a positive staining in more than 75% of the cells. There was a highly significant association between the proportion of positive cells and histologic grade of the infiltrating ductal carcinomas (p<0.004). However, there was no association with age, tumor size, hormone receptor content, or vascular embolism. There was a trend but no significant relationship between positive staining and overall survival either in each arm of the trial or in the overall population. Interestingly, we observed a higher relative risk of local relapse after conservative therapy in the boosted area in the group of mutated p53 (RR=4.41; p<0.0005). We conclude that, in this node-negative breast tumor population, alteration of p53 cannot predict the response to the chemotherapy. However, it may represent a useful marker of risk of local relapse and of radio resistance.

Adult↗
PubMed1998

Estrogen receptor negative and progesterone receptor positive primary breast cancer: pathological characteristics and clinical outcome. Institut Curie Breast Cancer Study Group.

The expression of estrogen (ER) and progesterone (PgR) receptors was analyzed in a retrospective series of 3000 patients who had operable primary breast cancer. Patients were stratified according to ER and PgR status and the study was focused on the two groups (ER-PgR+ and ER-PgR-) of patients whose tumors contained low levels of ER (< 15 fmol/mg protein), regarding potential response to endocrine therapy. The comparison of clinical or histological characteristics between ER-PgR+ and ER-PgR- patients was analyzed as well as the disease-related death and survival. The mean follow-up was 86.3 months. Among the 529 ER-patients, 62 were PgR+ (12%), whereas 467 were PgR- (88%). The ER-PgR+ and ER-PgR- populations represented 2% and 15.6% of the overall population, respectively. In ER- tumors, the PgR status was significantly related to: age, menopausal status, tumor size, SBR grade, and histological type, but not to the type of surgical treatment or to lymph node involvement. ER-PgR+ tumors had smaller size (64% T1 vs 43%) (p=0.004) and were more frequently grade I (28% vs 12%) than ER-PgR- tumors (p < 0.001). In addition, the patients with ER-PgR+ tumors were significantly younger (49.4 years vs 58.4 years; p < 0.0001), and were more frequently premenopausal (76% vs 36%, p < 0.001). The disease-free interval and the metastasis-free survival tended to be worse for ER-PgR- than for ER-PgR+ patients, but the difference was not statistically significant at 10 years. However, a small but significant difference in overall survival, in favor of the PgR+ group, was observed between the two groups during the first 5 years (p=0.03). We conclude that in combination with ER, PgR status defines a group of patients with clinical and biological specificity, which could be considered for specific endocrine therapy.

Adult↗
PubMed1997

Polymerase chain reaction compared with dot blotting for the determination of N-myc gene amplification in neuroblastoma.

The magnitude of N-myc amplification (NMA) influences the treatment strategy of localized neuroblastomas. Reliable assays are therefore needed for all types of tumor samples. The aim of this comparative study of 119 tumor samples was to determine whether a polymerase chain reaction (PCR)-based assay could replace the current dot blot assay as a routine and reliable means of determining NMA. The 2 assays exhibited comparable sensitivity and were completely concordant for samples containing at least 20% neuroblastoma cells. In their present state, both assays remain semi-quantitative since an absolute quantification of the N-myc copy number in clinical samples is limited by uncertainty about the amplification level of reference cell lines and by the estimation of the proportion of malignant cells. However, PCR offers several advantages over dot blotting, such as feasibility on minute samples, simplicity, standardization, rapidity and cost effectiveness.

Cost-Benefit Analysis↗
PubMed1997

Multicentric evaluation of the MDR phenotype in leukemia. French Network of the Drug Resistance Intergroup, and Drug Resistance Network of Assistance Publique-Hôpitaux de Paris.

The wide discrepancies in the frequency of 'positive' samples for multidrug resistance (MDR) phenotype within the same type of tumor observed in the literature justified the need for the definition of consensus recommendations. To define standard techniques of MDR phenotype measurement, we ran a large multicentric evaluation of the different methods available. Thirty-six French centers participated in the study, and 742 samples of 2-10 x 10(6) viable cells were sent by overnight express mail between December 1993 and February 1996. The same batches of MRK16, 4E3 and UIC2 were used. Nineteen samples of leukemia (12 AML, 1 ALL, 6 lymphoproliferative syndromes) and six leukemic cell lines with different levels of MDR expression were tested. Five meetings reached agreement concerning the guidelines for each technique, except immunocytochemistry. The 19 fresh samples were tested by each center using one to four techniques among cytofluorometry, immunocytochemistry, functional tests and RT-PCR. Five samples were diagnosed as 'negative' according to local criteria, with few discordant results (0 to 16% of 'positive' results). For all the 14 remaining samples, large discrepancies were observed from center to center, and from one technique to another. No correlations could be found between techniques. Flow cytometric analysis of cells already exposed to MRK16 or control IgG2A, fixed in paraformaldehyde and sent to centers did not reduce the discrepancies between centers in two of the four samples with moderate expression, emphasizing the role of histogram interpretation. The use of alternative monoclonal antibodies (4E3 and UIC2) did not reduce the discrepancies observed. In a second step, the K562 parental cell line, a low resistant subline (K562/HHT100, x7 resistance index to DNR) and a high resistant subline (K562/HHT300, x125 resistance index to DNR) were sent blindly three times, with an increasing level of recommendations for flow cytometry. Dramatic improvements were observed in cytometric results when the result was expressed as the ratio of arithmetic mean of fluorescence of antibody (10 microg of MRK16)/arithmetic mean of fluorescence of control (10 microg IgG2A): the proportion of expected results increased from 61 to 100% for K562, and from 37 to 85% for K562/HHT100. For uptake and drug efflux measurements, the use of 1 h uptake of 0.1 microM of rhodamine, followed by 1 h efflux +/-10 microM of verapamil, permitted an increased reproducibility of the technique from 71 to 100% for K562 and K562/HHT100. Whatever the technique used, concordant results were obtained for K562/HHT300. The immunocytochemistry, using several antibodies (MRK16, JSB1 and C219) gave many non-interpretable results (44%), due to a frequent high background and discordant results between antibodies in the same centers, and discordant conclusions between centers. The group does not recommend this technique for circulating tumoral cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

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.

Aged↗
PubMed1996

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.

Adult↗
PubMed1996

Decreased IL-1 beta and TNF alpha secretion in long-term bone marrow culture supernatant from Fanconi's anaemia patients.

Recent studies have shown that abnormalities of cytokine and lymphokine secretion are involved in the pathophysiology of Fanconi's anaemia (FA). In the present study, we quantified IL-1 beta, IL-1 receptor antagonist (IL-1Ra), IL-6 and TNF alpha protein levels in the supernatant of long-term cultures generated from BM cells of FA patients. Cell-free conditioned medium from long-term bone marrow culture was harvested every week at confluence and tested for interleukin secretion. IL-1 beta, IL-1Ra, TNF alpha and IL-6 protein secretion was assessed using immunoassays. IL-6 secretion was similar between controls and FA supernatants from wk 1 to wk 4. TNF alpha released from FA cells was consistently found at very low levels compared to control cells during the first 3 wk. Furthermore, secretion of IL-1 beta by cells from FA was always more than 2 standard deviations below the value of IL-1 beta found in normal donor cells from wk 1 to wk 4. In conclusion, in addition to a stem cell defect, a marked decrease in IL-1 beta and TNF alpha secretion may be one of the mechanisms leading to bone marrow failure in individuals with Fanconi's anaemia.

Adolescent↗
PubMed1996

Hematopoiesis research in aplastic anaemia induced by accidental protracted radiation.

Over the past few years there have been 2 radiation-related accidents involving a large number of individuals: the April 1986 accident in Chernobyl nuclear power station in the Ukraine and the September 1987 accident in Goiania, Brazil. These 2 radiation-related accidents highlight the major question raised by radiation-induced injury to the haematopoietic system, that is: does a given patient suffer from a reversible or an irreversible haematopoietic stem cell damage? Although about 350 radiation accidents involving several thousand people are known from the literature, in-depth haematopoiesis analyses of individuals after a radiation-related accident have rarely been reported. In this paper we present the case of a young man with radiation-induced aplasia and compare some biological data to those of 16 normal individuals and of 17 patients with acquired aplastic anaemia. Our patient was clinically and biologically (as assessed by long-term bone marrow culture) indistinguishable from patients with idiopathic acquired aplastic anaemia. Furthermore, therapeutic attitudes in this patient are discussed. In-depth study of such radiation-induced aplastic anaemia cases can shed some light in the understanding of this disease and may help in therapeutic decisions.

Adolescent↗
PubMed1994

EGF modulation of the ras-related rhoB gene expression in human breast-cancer cell lines.

The mRNA levels of the ras-related human rhoA, rhoB and rhoC genes were studied in human breast-cancer cell lines (HBCal), and in normal and immortalized mammary epithelial cells (HMEC) by Northern blot analysis and in situ hybridization. In contrast to the ubiquitous rhoA and rhoC gene expression, dramatic variations in the mRNA level of the rhoB gene were evidenced. The rhoB mRNA level appeared to be inversely correlated to the amounts of the epidermal-growth-factor(EGF) receptors in these cells. The rhoB transcripts were detected at high levels in ZR75-1, MCF7, HSL 53, HSL 59, HSL 90, T47D and SKBR3 HBCal, at hardly detectable levels in BT 20, MDA-MB 231 and H466B HBCal and at intermediate levels in normal and immortalized breast epithelial cells. Rapid and transient induction of the rhoB transcription was observed after EGF treatment in serum-deprived MDA-MB231, T47D and immortalized epithelial cells. In contrast, no modulation of rhoB expression by EGF could be objectified in the MCF7 and ZR75-1 cell lines. Yet a normal function of EGF receptors was evidenced, since the immediate early gene c-fos was rapidly induced, suggesting a constitutive expression of rhoB in these cell lines bypassing the regulation by EGF. In human mammary epithelial cells, rhoB mRNA is rapidly and transiently induced with EGF concentrations known to stimulate cell proliferation. This suggests that the rhoB product might be involved in a cascade that initiates or promotes cell proliferation, and plays an important role in EGF-stimulated growth of breast normal and cancer cells.

Blotting, Northern↗