Search

Objective: Our aim was to study fertility issues, attitudes towards reproductive techniques and fertility preservation options in women of reproductive age with endometriosis.Study design: In 2018 we conducted a web-based survey on fertility issues in women aged 18-40 years with endometriosis. Participants were recruited via advertisements on social media and local endometriosis support groups. Participants completed a self-developed online questionnaire evaluating the following dimensions: sociodemographic, medical data, parental project, knowledge and attitudes toward endometriosis and fertility, means used to access information, and reproductive choices.Results: The majority of women (96 %) worried about the impact of endometriosis on their fertility. Approximately half of them (52 %) reported having received sufficient information concerning the effect of endometriosis on fertility from their doctor, whereas 31 % had discussed fertility issues with their doctor but desired further information. In contrast, only a minority (27 %) of women considered themselves well-informed on fertility preservation options. Information given by specialists on endometriosis and reproduction was considered most useful. Information mediated through patient support groups was also highly rated, whereas information given by the general gynecologist was less highly rated. The majority of women would consider assisted reproductive techniques (74 %) or adoption (70 %) in case of infertility. Interestingly, 72 % of women would undergo oocyte vitrification for fertility preservation, whereas only 37 % would resort to oocyte donation.Conclusion: This is the first survey to address the topic of fertility issues from the patient's perspective in women with endometriosis. The vast majority of women attach great importance to a discussion about fertility possibilities and only a minority of women consider themselves well-informed. Our results highlight the importance of addressing the issue of fertility in women with endometriosis. Special attention should be given to information and counselling about fertility preservation options since most women consider their knowledge on the topic insufficient. Knowledge and attitudes to counsel endometriosis patients on fertility issues and fertility preservation options should be included in the training curricula of gynecologists. Adequate information on reproductive aging, risk factors for infertility, and reproductive choices, including oocyte vitrification, should be incorporated into follow-up visits for endometriosis patients.

P-glycoprotein belongs to the ATP binding cassette transporters, responsible for the multidrug resistance of cancer cells. These transporters efflux hydrophobic drugs outside cells and decrease their therapeutic efficacy. The aim of this study was to investigate the effect of vandetanib, an oral tyrosine kinase inhibitor of EGFR, VEGFR 2 and RET kinases, on the functionality of P-gp after a 24 h-treatment at therapeutic concentration (2 μM), and its ability to increase the cytotoxicity of chemotherapeutic agents in multidrug resistance cancer cells. In this study we found that IGROV1-DXR and IGROV1-CDDP cells were resistant to doxorubicin and cisplatin respectively, compare to parental cell line IGROV1. The parental sensitive and the two resistant cell lines similarly expressed MRP1 and did not express BCRP. Moreover, in contrast to the IGROV1 and IGROV1-CDDP cells, IGROV1-DXR cell line overexpressed P-gp. Functional activity studies demonstrated that MRP1 was not functional and the MDR phenotype in IGROV1-DXR cells was linked to P-gp functionality. Results also showed that vandetanib reversed resistance to doxorubicin in IGROV1-DXR cells, but not to cisplatin in IGROV1-CDDP cells. After 24 h of treatment, vandetanib increased the accumulation of rhodamine 123 and calcein AM, demonstrating a functional inhibition of the transporter. In IGROV1-DXR cell line, vandetanib reverse resistance to doxorubicin by inhibiting the functionality of P-gp. In conclusion, vandetanib should be an option for drug combination in patients already developing a P-gp mediated multidrug resistance.

Resume Bien que l’incidence du cancer soit en augmentation, les traitements anticancereux sont devenus plus efficaces, avec pour resultat, un accroissement du nombre de femmes survivantes, soumises aux consequences a long terme de la chimiotherapie. Un des principaux effets indesirables des traitements anti-cancereux indesirables est represente par l’insuffisance ovarienne prematuree. Ainsi, les jeunes femmes soumises a ce type de traitement sont demandeuses d’une preservation de leur fertilite. Classiquement, la cryopreservation embryonnaire et/ou ovocytaire apres stimulation ovarienne, represente la technique de reference, offrant les meilleurs resultats. Cependant, nombreuses sont les patientes chez qui la stimulation ovarienne n’est pas realisable, faute de temps ou en raison d’une pathologie sous-jacente estrogenodependante. Pour ces patientes, la technique de maturation ovocytaire in vitro (MIV) a ete proposee, permettant un recueil ovocytaire immediat, sans stimulation par les gonadotrophines exogenes, independamment de la phase du cycle. Par ailleurs, elle est utilisable en combinaison avec la cryopreservation de tissu ovarien. Dans cette revue, nous discuterons de la place de la MIV dans la preservation de la fertilite de la femme jeune.

The anti-tumor effect of the Moroccan endemic thyme (Thymus broussonettii) essential oil (EOT) was investigated in vitro using the human ovarian adenocarcinoma IGR-OV1 parental cell line OV1/P and its chemoresistant counterparts OV1/adriamycin (OV1/ADR), OV1/vincristine (OV1/VCR), and OV1/cisplatin (OV1/CDDP). All of these cell lines elicited various degrees of sensitivity to the cytotoxic effect of EOT. The IC50 values (mean +/- SEM, v/v) were 0.40 +/- 0.02, 0.39 +/- 0.02, 0.94 +/- 0.05, and 0.65 +/- 0.03% for OV1/P, OV1/ADR, OV1/VCR, and OV1/CDDP, respectively. Using the DBA-2/P815 (H2d) mouse model, tumors were developed by subcutaneous grafting of tumor fragments of similar size obtained from P815 (murin mastocytoma cell line) injected in donor mouse. Interestingly, intra-tumoral injection of EOT significantly reduced solid tumor development. Indeed, by the 30th day of repeated EOT treatment, the tumor volumes of the animals were 2.00 +/- 0.27, 1.35 +/- 0.20, and 0.85 +/- 0.18 cm(3) after injection with 10, 30, or 50 microL per 72 h (six times), respectively, as opposed to 3.88 +/- 0.50 cm(3) for the control animals. This tumoricidal effect was associated with a marked decrease of mouse mortality. In fact, in these groups of mice, the recorded mortality by the 30th day of treatment was 30 +/- 4, 18 +/- 4, and 8 +/- 3%, respectively, while the control animals showed 75 +/- 10% of mortality. These data indicate that the EOT which contains carvacrol as the major component has an important in vitro cytotoxic activity against tumor cells resistant to chemotherapy as well as a significant antitumor effect in mice. However, our data do not distinguish between carvacrol and the other components of EOT as the active factor.

Advances on cryopreservation techniques now allow considering oocyte, embryo or ovarian tissue freezing for female fertility preservation. Originally developed for patients suffering from cancer, fertility preservation has rapidly invaded others medical fields, and represents now the standard of care for all young patient diagnosed with a disease that could impair fertility or having to receive possibly gonadotoxic treatment. As a result, autoimmune diseases, some genetic pathologies or iterative pelvic surgeries, at risk of premature ovarian failure, have become common indications of fertility preservation. In addition, the social egg freezing aiming at preventing the age-related fertility decline is still debated in France, although authorized in numerous countries. This review will discuss the different strategies of fertility preservation in young girls and women of reproductive age, regarding different medical or non-medical indications.

Purpose Cancer chemotherapy typically combines anticancer drugs from different mechanisms of action. However, cancer cells could become resistant to chemotherapy via P-gp or other ATP binding cassette proteins. The objective of this study was to evaluate whether cetuximab, monoclonal antibody directed toward epidermal growth factor receptor, could increase intracellular concentration of conventional chemotherapy by interacting with P-gp. Methods Two human ovarian carcinoma (IGROV1) and two human embryonary kidney (HEK) cell lines, overexpressing or weakly expressing P-gp, were used. Their EGFR expressions were compared. Cetuximab effect on P-gp functionality was evaluated by measuring doxorubicin (P-gp fluorescent substrate) intracellular accumulation. Cetuximab ability to increase doxorubicin cytotoxicity was evaluated by MTT test. A quaternary structure model of the P-gp-Cetuximab complex was established. Results Exposure of cetuximab in therapeutic concentrations range with doxorubicin led to significant doxorubicin accumulation and reversion of doxorubicin resistance in P-gp expressing cells lines. Molecular modeling of P-gp-cetuximab interactions showed that cetuximab is able to bind P-gp extracellular part. Conclusions Cetuximab increases a P-gp substrate intracellular accumulation in both P-gp expressing cell lines, independently of their EGFR expression. One hypothesis is that cetuximab binding on P-gp could hamper the conformational changes that occur during drugs efflux. Our results offer new possibilities of research on monoclonal antibodies influence in MDR phenomena.

N-myc oncogene amplification is one of the most established prognostic factors in neuroblastoma (NB), a young children solid tumor. Amounts of ferritin, an iron storage protein, are abnormally increased in serum of patients with advanced stage disease. N-myc amplified NB cells can synthesize zinc metalloenzymes allowing tumor invasion and metastases formation. The aim of this study was to find a relationship between N-myc amplification and trace metals in human neuroblasts. Coupling PIXE and RBS techniques, nuclear microprobe allowed to analyze elemental distributions and to determine trace metal concentrations within cultured neuroblasts characterized by various degrees of N-myc amplification. They were compared to trace metal distributions and concentrations in tumor xenograft models of human NB, after injection of cells from the same lines in athymic nude mice. Our data allowed to establish a relation between trace metal contents and mechanisms of NB oncogenesis, amplified cell lines representing more aggressive phenotypes of the disease. They should be confirmed by analysis of cultured neuroblasts and tumors issued from a non-amplified cell line transfected with the N-myc oncogene.

N- myc oncogene amplification is a powerful predictor of aggressive behavior of neuroblastoma (NB), the most common solid tumor of the early childhood. Since N- myc overexpression – subsequent to amplification – determines a phenotype of invasiveness and metastatic spreading, it is assumed that N- myc amplified neuroblasts synthesize zinc metalloenzymes leading to tumor invasion and formation of metastases. In order to test a possible relation between N- myc oncogene amplification and trace metal contents in human NB cells, Fe, Cu and Zn concentrations have been measured by nuclear microprobe analysis in three human neuroblastoma cell lines with various degrees of N- myc amplification. Elemental determinations show uniform distribution of trace metals within the cells, but variations of intracellular trace metal concentrations with respect to the degree of N- myc amplification are highly dependent on the nature of the element. Zinc concentration is higher in both N- myc amplified cell lines (IMR-32 and IGR-N-91) than in the non-amplified cells (SK–N–SH). In contrast, intracellular iron content is particularly low in N- myc amplified cell lines. Moreover, copper concentrations showed an increase with the degree of N- myc amplification. These results indicate that a relationship exists between intracellular trace metals and N- myc oncogene amplification. They further suggest that trace metals very probably play a determinant role in mechanisms of the neuroblastoma invasiveness.

Some transition metals play important regulatory roles in gene expression. The disturbance of their cellular levels could be involved in oncogene expression and tumorigenesis. Nuclear Microprobe Analysis (NMPA) was used to measure cellular trace metal levels (Mn, Fe, Cu, Zn) in two human neuroblastoma cell lines characterized by distinct genotypes. In this paper, a specific protocol established for sample preparation of neuronal cultured cells is described. Trace metal concentrations in SK-N-SH and IGR-N-91 cells exhibiting respectively a single copy, and 60 copies, of the N-myc oncogene are reported. A brief discussion on experiment design for NMPA of trace metal functions in gene expression is also presented.

Macro-and Micro-PIXE analysis were applied to study the mechanisms of cellular resistance to cisplatin, a chemotherapeutic agent, widely used nowadays for the treatment of ovarian cancer. Two cultured cell lines, a cisplatin-sensitive and a resistant one, were compared for their trace elements content and platinum accumulation following in vitro exposure to the drug. Bulk analysis revealed significant differences in copper and iron content between the two lines. Subsequent individual cell microanalysis permitted us to characterize the response of the different morphological cell types of the resistant line. This study showed that the metabolism of some trace metals in cisplatin-resistant cells could be affected but the exact relationship with the resistant phenotype remains to be determined. From a technical point of view, this experiment demonstrated that an accurate measurement of trace elements could be derived from nuclear microprobe analysis of individual cell.

A comprehensive questionnaire survey with limited environmental measurements was undertaken in a large sealed office complex where health complaints had been made by employees since the complex was first occupied. Most respondents suffered from upper respiratory tract irritation, eye and skin irritation, and many less specific complaints. Symptoms started shortly after first employment, were troublesome only at work, and persisted at other work locations within the complex. Employees who worked in cubicles tended to complain more than those who worked in open areas or closed offices; however, evidence of less than optimal ventilation, temperature, and humidity correlated poorly with symptom prevalence. The building was designed and ventilated for open-plan use; later partition into offices and cubicles appeared to aggravate the situation. Although concern about pregnancy outcome was expressed by women who conceived while employed at the complex, rates of spontaneous abortion and fetal defect were close to expectation.

Although female cancer incidence may be on rise, antineoplastic regimens have become more successful. As a result, an increasing number of women with cancer survive to endure the long-term consequences of chemotherapy. One of the most important long-term consequences of cancers treatments in young female is premature ovarian failure and infertility. Because of the increasing survival rates, many of these young women are seeking methods to preserve their fertility. Currently, embryo/oocytes cryoporeservation obtained after ovarian stimulation appears to provide the best fertility preservation option. However, patients may not have sufficient time to undergo ovarian stimulation prior to chemotherapy and/or the hormones used in ovarian stimulation are contra-indicated for estrogen-dependant tumors. In vitro maturation of oocytes (IVM) has been suggested to avoid ovarian stimulation and time requirement in patients with cancer, and can be combined with ovarian tissue cryobanking. In this review, we will discuss the position of IVM in the strategy of fertility preservation in young women.

The p53 gene homologue, p73, is located on the 1p36-3 locus, which is frequently deleted in human neuroblastoma (NB). A survey of 61 NB showed that among 33% of informative cases, p73 loss of heterozygosity (LOH) occurred in 7 of 20 (35%).LOH pattern of vicinal markers suggested that the p73 gene could not be considered as the candidate NB suppressor gene. Moreover, comparative measurements of allelic expression in tumors and corresponding patient lymphocytes indicate that pure biallelism is much more frequent in lymphocytes than in tumors (71% vs 30%, P= 0.05), which suggests that disequilibrated allelic expression is associated with NB disease.Therefore, in the p73 LOH NBs, the p73 gene could be altered in the maintained allele not by mutations [Ishimiya et al.: Med Pediatr Oncol, this issue], but rather by an abnormal transcription.

Our aim was to compare the prognostic value of c-erbB-2 gene amplification analyzed by Southern blot with that of protein (p185) over-expression measured by immunohistochemistry in 172 patients with operable breast cancer (BC). Amplification and p185 over-expression were found in 31 (18%) and 51 (30%) BCs, respectively. All but 1 of the tumors showed both amplification and over-expression, while 21 (12%) tumors displayed over-expression without amplification. The risk of death associated with c-erbB-2 gene amplification and p185 over-expression was evaluated by multivariate analysis, taking into account tumor size, histoprognostic grade, hormone receptors and axillary node status. During a mean follow-up of 9.5 (+/-2) years, node involvement (p0.001), c-erbB-2 gene amplification (p = 0.02) and negative hormone receptors (p = 0.02) were found to be independent prognostic indicators of the risk of death. Over-expression of p185 with no amplification was not correlated with this risk. When the risk of death associated with c-erbB-2 amplification was studied according to chemo- and hormone therapy, no significant difference was observed between subgroups of subjects. Amplification was also associated (p = 0.02) with the risk of multifocal distant metastases (i.e., metastases detected concomitantly in at least 2 sites) and, thus, with BC aggressiveness. These data show the importance of c-erbB-2 gene amplification in predicting the long-term outcome of patients and in selecting eligible patients for c-erbB-2-targeted therapies.

Neuroblastoma is a very common solid tumor which arises in childhood and shows an extreme heterogeneity at the clinical, histological and genetic levels. Besides age and stage, N-myc amplification and 1p deletion are prognostic factors of the disease: in Europe, these genetic markers are used to conduct therapy. In France, N-myc amplification is a factor of bad prognosis which leads, in all forms of the disease including localised forms and metastatic forms of children aged of less than 1 year, to a myeloablative treatment with autologous hematopoietic stem cells transplantation. By contrast, N-myc amplification has no impact on the survival of children aged of more than 1 year with a poor prognosis (30% overall survival, 5 years) but this genetic abnormality is taken into account to treat primary tumor of these patients. In an attempt to find out prognostic factors of these aggressive forms of the disease, various pathways (apoptosis, differentiation angiogenesis, detoxication, immune response) have been recently surveyed, but studies have been carried out on a limited number of genes. Moreover, experimental models of human metastatic neuroblastoma have been obtained in which variations of genes transcript levels involved in these pathways, are observed. The current break-through of cDNA microarrays allows to develop a dynamic transcriptomic scanning of these models as well as of tumors and bone marrows from patients upon conventional chemotherapy. This technology will enable: i) to define molecular entities of the metastatic disease; ii) to apply adapted treatment; iii) to develop new therapeutic strategies.

We have studied the occurrence and association of 11q deletions with other chromosomal imbalances in Stage 4 neuroblastomas. To this purpose we have performed comparative genomic hybridization (CGH) analysis on 50 Stage 4 neuroblastomas and these data were analyzed together with those from 33 previously published cases. We observed a high incidence of 11q deletion in Stage 4 neuroblastoma without MYCN amplification (59%) whereas 11q loss was only observed in 15% of neuroblastomas with MYCN-amplification (p = 0.0002) or 11% of cases with 1p deletion detected by CGH (p = 0.0001). In addition, 11q loss showed significant positive correlation with 3p loss (p = 0.0002). Event-free survival was poor and not significantly different for patients with or without 11q deletion. Our study provides further evidence that Stage 4 neuroblastomas with 11q deletions represent a distinct genetic subgroup that typically shows no MYCN-amplification nor 1p deletion. Moreover, it shows that neuroblastomas with 11q deletion also often present 3p deletion. This genetic subgroup shows a similar poor prognosis as MYCN amplified 4 neuroblastomas.

Auteur(s) : J Benard Un caractere fondamental de la cellule carcinomateuse est son independance d’ancrage, autrement dit sa capacite a survivre en absence de matrice extracellulaire (MEC), la structure composee de l’ensemble de macromolecules secretees par la membrane basale d’un epithelium. En revanche, dans les memes conditions, la cellule normale connait un phenomene d’anoikis ou mort cellulaire par perte d’ancrage via un processus apoptotique caspase-dependant ou via [...]

In January 1997, PCR genomic analysis of the TSG101 gene showed frequent large intragenic deletions. The investigators used a small cohort of sporadic breast cancers. Li et al. proposed human TSG101 as a breast tumor suppressor gene. Since then, several teams have worked on large series of breast cancers, using a variety of techniques. They have shown that intragenic deletion, if it exists at all, is rare. Is TSG101 a tumor gene or an impostor?

Between March 1990 and December 1994, 316 consecutive children with localised neuroblastoma were registered in the French NBL 90 study. In addition to the assessment of a new chemotherapy regimen in unresectable neuroblastoma, we evaluated the prognostic significance of MYCN amplification and loss of the short arm of chromosome 1 (LOH1p). MYCN was found in 22/225 children (10%) and associated with unfavourable clinical features such as age at diagnosis1 year and large and unresectable tumours. LOH1p was observed in 9/91 patients (10%), of whom some had favourable prognostic factors such as age at diagnosis1 year (n = 4), INSS stage 1 or 2 (n = 3) and no MYCN amplification (n = 4). Overall survival (OS) and event-free survival (EFS) were, respectively, 56% and 22% (median follow-up: 36 months) for children with LOH1p compared with 97% and 94% for those without (log-rank = 10(-8)). All except 1 of the 5 children with MYCN amplification and LOH1p relapsed and ultimately died of the disease. Among the 4 with LOH1p and no MYCN amplification, recurrence occurred in 3 (2 local, 1 metastatic), all alive in second remission after salvage therapy (12-19 months after the relapse). In multivariate analysis, LOH1p was the strongest prognostic indicator for subsequent relapse. LOH1p appears more discriminant than MYCN amplification for predicting the risk of recurrence in children with localised neuroblastoma. However, its analysis was possible in only 30% of our patients and its final impact on survival should be confirmed in larger, prospective studies in order to stratify subsequent treatment.

Germline mutations in the p16 and CDK4 genes have been reported in a subset of melanoma pedigrees, but their prevalence is not well known. We searched for such germline mutations in 48 French melanoma-prone families selected according to two major criteria: families with at least three affected members (n = 20) or families with two affected members, one of them affected before the age of 50 (n = 28), and one additional minor criterion. Sixteen different p16 germline mutations were found in 21 families, while one germline mutation, Arg24His, was detected in the CDK4 gene. The frequency of p16 gene mutation in our sample (44%) is among the highest rates yet reported and the CDK4 mutation is the second mutation detected in this gene worldwide. In summary, our results show frequent involvement of the p16 gene in familial melanoma and confirm the role of the CDK4 gene as a melanoma-predisposing gene.

Since there is no consensus on the techniques for multidrug resistance (MDR) phenotype evaluation, many discrepancies concerning the importance and frequency of mdr1 gene expression in leukemias and solid tumors are observed in the literature. In order to establish an inter-laboratory consensus in France, a multicenter study was carried out to propose further guidelines for MDR phenotype evaluation. The techniques used by the 38 laboratories participating in the trial were: immunodetection (immunohisto and/or cytochemistry, flow cytometry), functional tests, reverse transcription-polymerase chain reaction (RT-PCR) or Northern blot. We present the results obtained by 19 laboratories concerning the measurement of mdr1 gene expression assessed by RT-PCR or Northern blot in: (1)19 samples of tumor cells obtained from leukemic patients; (2) six solid tumor samples obtained at surgery; (3) eight cell lines exhibiting variable levels of resistance, and; (4)10 preparations of RNA and of cDNA obtained from solid tumors. Standardization of the RT-PCR technique and preliminary results comparing RT-PCR with immunohistochemistry in solid tumors are also reported.

When N-myc copy number was assessed by molecular biology, it has been proven that an amplification of the oncogene was a bad prognosis in childhood neuroblastoma, and the same goes for DNA-diploidy. This study concerns the development of a biparametric flow cytometric analysis of 2 neuroblastoma cell lines (SK-N-SH and IGR-N-91), which exhibited respectively 1 and 60 copies of the N-myc oncogene. An indirect immunofluorescence technique allowed N-myc oncoprotein staining and an isotypic control was used to assess the threshold of specific fluorescence. Simultaneously, a double staining with propidium iodide gave the nuclear DNA content. For both types of cells, the level of N-myc expression was calculated as a fluorescence index (IF). IF for IGR-N-91 appeared 2.5 times higher than those of SK-N-SH. This fluorescence index increases significantly during the exponential growth of N-myc amplified cells, whereas it does not vary for SK-N-SH. During IGR-N-91 tumoral evolution, the cell line which derived from murine heart metastasis was the only one to show an increased IF. When applied to 10 neuroblastoma cell suspensions, this double staining showed an high IF for only 1 N-myc amplified case. A poor cell yield after tumoral dissociation and too much debris did not allowed the calculation of IF for half of them, which hampered a routine development of this technique.

An experimental model of advanced human neuroblastoma, IGR-N-91, which is able to disseminate in the nude mouse, has been described. The present study was designed to ascertain which cell population from the IGR-N-91 primary tumour actually disseminates throughout the animals. In s.c. IGR-N-91 tumour xenografts, 3 areas, called pearly, vascularized and haemorrhagic, depending on the presence of blood vessels and haemorrhagic suffusions, were consistently observed and independently resected. Molecular analysis of tumour materials revealed a significant increase in MYCN and max gene transcript levels in the haemorrhagic area, as compared with the pearly and vascularized areas. Given the growth kinetics observed both in vitro and in vivo, and the DNA flow-cytometry profiles of tumour cells obtained from the haemorrhagic area, this transcriptional increase did not appear to be associated with enhanced proliferation. In this area of the tumours, multidrug-resistance-related genes, i.e., MDRI, MRP, GST-pi and topoisomerase II alpha were activated concomitantly with MYCN and max genes. The same observations were made, except for the topoisomerase-II alpha gene, when sub-lines derived from metastases were compared with that derived from the primary tumour. These data demonstrate that over-expression of several genes determining the multi-drug-resistance phenotype precedes the metastatic spread of IGR-N-91 NB tumour cells in the nude mouse. Data also suggest that the cell sub-population exhibiting this pleiotropic over-expression within the primary tumour undergoes selection during metastatic dissemination.

Due to inefficacy of chemotherapy in several cancers, chemoresistance mechanisms which are intrinsic to tumor cells have been extensively described in human cancer cell lines. Detoxifying mechanisms including active efflux pumps (P-gp, MRP or LRP) and/or drug inactivation (glutathione) as well as increased DNA repair have been identified and demonstrated to be involved in chemoresistance processes. Moreover expression of genes implicated in proliferation, differentiation or apoptosis functions has been shown to indicate drug response. Several mechanisms very often coexist within the tumor cell: it is possible even that detoxifying mechanisms are dependent on oncogenes and suppressor genes regulating proliferation, differentiation and/or apoptosis. In human tumor specimens, some of these mechanisms are regularly found and thus lead to develop strategies to block them. In that respect, the first example is the development of modulators of P-gP, a membrane efflux protein, which constitutes the archetype of detoxifying drug mechanisms. In spite of technical difficulties encountered to properly identify and quantify expressions of these biomarkers, ongoing research in cancer chemotherapy now largely relies on chemoresistance mechanisms.

Cisplatin-induced apoptosis and p53 gene status were analyzed in human ovarian carcinoma using a parental IGR-OV1 line and a derived cisplatin-resistant IGR-OV1/DDP subline. Compared with parental cells, cisplatin-resistant cells exhibited a 5-fold higher resistance index and a 2-fold longer doubling time. Cisplatin induced apoptosis in both cell lines, as assessed by cell morphology and the presence of a DNA ladder. However, high concentrations were necessary to induce apoptosis in resistant cells. These cells elicited a 5-fold decrease in the number of platinum atoms bound per nucleotide. IGR-OV1/DDP cells also exhibited enhanced drug efflux and a higher glutathione content. Our data suggest that the levels of cisplatin-DNA lesions are critical for drug sensitivity and apoptosis induction in this in vitro ovarian carcinoma model. Comparative analysis of the p53 gene in sensitive and resistant cells revealed the presence of the same heterozygous mutation in exon 5. A 2-fold increase in p53 mRNA and protein amounts was observed in resistant cells as assessed by Northern and Western blots, respectively. Immunocytochemical staining revealed a higher percentage of p53 stained nuclei in resistant cells. RT-PCR analysis of p53 transcripts showed that both wild-type and mutated alleles were transcribed in sensitive as well as in resistant cells. However, mutated transcripts were 1.5-fold more abundant than wild-type transcripts in sensitive cells, whereas they were 2-fold higher in resistant cells. In addition, mdm-2 protein was over-expressed in resistant cells. Our results address the question of the functionality of p53 protein and its possible role in apoptosis induction in this model. In resistant cells, p53 protein might be inactivated by 2 mechanisms: mutation and complexation with mdm-2 protein. Therefore, the presence of non-functional p53 in resistant cells might be involved in the relative failure of cisplatin-induced apoptosis in these cells.

Knowledge about genetic alterations specific to the metastatic process and chemoresistance in neuroblastoma is progressing steadily. Low or no CD44 expression, increased NM23 expression and specific mutations of the 5′ coding regions of NM23 are distinct features of aggressive, metastatic neuroblastoma. MYCN down-regulates Class IHLA antigen expression in many neuroblastoma cell lines and, in turn, may be regulated by a suppressor gene. The MYCN amplified human neuroblastoma cell line, IGR-N-91, established in vitro , metastasises in the nude mouse and has exhibited co-activation of MYCN and PGY1, resulting from direct activation of the oncoprotein on the PGY1 promoter. In this model, the MYCN product activates angiogenesis, the dissemination process and chemoresistance via specific genes ( PGY1 and GST3 ). MYCN , like the BCL-2 and TP53 products, may also play a key role in apoptosis. The implication of these genes in the potential for metastasis and chemoresistance in neuroblastoma is discussed.

The prognostic value of the MDR1 gene expression in neuroblastoma (NB) was assessed in a multivariate analysis performed in a series of 84 patients (pts) taking into account the main known clinical and biological factors of the disease, i.e., age, stage, MYCN genomic content and DNA ploidy index. Twenty seven children were1 year (yr), 13 presented with stage I and II, 7 with stage IV-S, 17 with stage III and 47 (56%) with stage IV. Tumor specimens were obtained from involved bone marrow (n = 12) or surgical primary tumor specimens (n = 72). MDR1 gene expression was measured by Northern hybridization technique and expressed in arbitrary units (a. u.) (Goldstein et al., 1989). Analysis of MYCN genomic content and DNA ploidy index were performed by Southern blot hybridization technique and flow cytometry, respectively. Out of 84 tumor specimens 19 (23%) showed MYCN amplification (3 copies/haploid genome). In 24 cases (29%) no detectable MDR1 gene transcript was found (0 a.u.) whereas 42 (50%) had a value in the range 1-30 a.u., and 18 (21%) a value beyond 30 a.u.. High transcript levels were found in localized as well as in metastatic NB (NS). No significant correlation between MDR1 gene expression, age, stage, or MYCN genomic content was found In univariate analysis stage IV, age1 yr, MYCN amplification, diploid DNA content and high MDR1 gene transcript levels were significantly related to an increased risk of death. In multivariate analysis only stage IV, MYCN amplification and MDR1 overexpression remained significantly associated with an increased risk of death.(ABSTRACT TRUNCATED AT 250 WORDS)

To determine whether over-expression of the MDR1 gene may result from activation of its promoter by differentiating agents, the activity of the human MDR1 proximal promoter (MDR1 pp) transfected to 2 neuroblastoma lines treated with retinoic acid and forskolin was first measured using transient expression assays while the MDR1 mRNA levels were measured by Northern blots. The results indicate that retinoic acid and forskolin were able to activate the human MDR1 pp in a dose dependent manner after transfection of the MDR1pp- CAT constructs in the 2 cell models tested, i.e., SK-N-SH and IGR-N-91, a new human neuroblastoma cell line. A significant increase in MDR1 gene transcript levels was observed upon treatment with differentiation inducers in SK-N-SH but not in IGR-N-91 neuroblasts. These results suggest that the induction of the MDR1 gene promoter is necessary but not sufficient to lead to an increase in MDR1 gene transcript levels, according to the neuroblast cell line considered.

N-myc amplification and ploïdic index are important prognosis factors in neuroblastoma. Combined overexpression of the multidrug resistance gene, MDR1 and of Glutathion-S-Transferase, GST-pi may be related to the response of tumors to chemotherapy. Measurements of these parameters may contribute to define responders and non-responders to chemotherapy and provide the clinician with additional criteria to manage treatment.

This review summarizes the basic aspects of multidrug resistance (MDR). We first propose a brief reappraisal of the occurrence of MDR encoded P-glycoprotein, (P-g-P) in various normal and tumor tissues. We then present a series of studies undertaken to estimate the MDR1 gene expression or the presence of P-g-P in various human cancers. Finally, we conclude on the potential use of P-g-P measurements in some cancers as a useful if not powerful means of reversing clinical multidrug resistance.

In vitro models with multiple drug resistance (MDR) phenotype have been frequently related to hyperproduction of the 170 kd membrane glycoprotein, the so-called 170 GP. This protein is a pump able to extrude from cytoplasm drugs with various structures and mechanisms such as doxorubicin (DXR) or vinblastin (VLB). The MDR1 gene encodes the GP 170. MDR1 gene expression is low in most of the normal tissues, but high in some tissues such as colon, kidney, or liver. In these tissues, the GP 170 would ensure a detoxifying function related to cellular toxic compounds. There is a broad range of MDR1 gene expression in human tumors as a result of several factors. Of particular importance are the tissue origin from which the cancer derives and previous chemotherapy. In some cancers which often exhibit acquired chemoresistance, such as non Hodgkin's lymphomas, leukemias, sarcomas or neuroblastomas, an increase of MDR1 gene expression following previous chemotherapy has been frequently observed. Moreover in these cancers, a relationship between MDR1 transcript levels and clinical response to chemotherapy could exist as shown in several studies including one of ours. Hematosarcoma in the adult and some pediatric cancers seem to be models in which MDR1 gene expression may have a clinical relevance. Thus, an increase of MDR1 gene expression during the course of chemotherapy would lead the clinician to choose "non MDR related" agents such as DXR, VLB; or to use agents that are able to reverse MDR phenotype.

The thermodynamics properties of some metallic 2D sulphides and 3D sulphides are presented in the shape of diagram following Ellingham's model. For sulphur adsorption the quantities at saturation (Γ sat s ) are collected on several metals as well as the ranges of stability in temperature and pressure. A close correlation exists between the heats of formation of 2D and 3D compounds.

The paper studies the second best solution of an optimal taxation problem, when some prices are subject to exogenous constraints. We show that, under specific conditions upon preferences and technology, the signs of optimal taxes can be deduced from the signs of cross price elasticities. The conditions can be related to a special form of separability (‘Morishima separability’), which fits reasonably well to a number of national consumption structures.

Isothermal oxidation treatments were carried out on an Fe-C alloy (0.4 % C): (a) in almost dry air around A1, and also with an Fe-C alloy (0.5% C) and IRSID pure iron; (b) in dry air ( $${\text{P}}_{H_2 O} \simeq 10^{ - 5} $$ nm Hg); (c) in almost dry air(1–2% water vapor) at 700° C; and (d) in moist air (31% water vapor). Theresults are as follows: The rate of oxidation at a temperature below A1depends chiefly on alloy structure, i.e., on thermal history of the sample.The water vapor content of the air strongly influences the scale adherenceas well as the rate of oxidation of the Fe-C alloys below A1, but has virtuallyno effect on the rate of oxidation of pure iron. Under the same conditions, avery light decarburization of metal occurs in air, whereas no decarburizationoccurred in air with 13% water vapor.

Resume L'etude de l'autodiffusion des ions dans les halogenures alcalins polycristallins constitues de grains de differentes grosseurs a ete realisee en fonction de la temperature. Dans tous les cas, l'energie d'activation d'autodiffusion des ions est la meme, que la migration s'effectue dans des monocristaux ou dans des polycristaux. Dans tous les composes, a l'exclusion des sels de cesium, la vitesse de diffusion du cation est la meme, que l'on opere sur des mono-ou des polycristaux; par contre, celle de l'anion s'accroit et cet accroissement est d'autant plus important que la dimension moyenne des cristaux constituant les agregats polycristallins est plus petite. Cependant, dans le cas des sels de cesium, la vitesse de diffusion du cation est egalement influencee par la presence des surfaces intercristallines. Il est possible de relier cet accroissement de vitesse de diffusion a la polarisation des ions. Plus l'ion est polarise, plus l'influence des surfaces intercristallines est importante et ceci quelle que soit la polarite de l'ion diffusant. Une etude autoradiographique confirme ces resultats.

Resume Une analyse prealable est faite du processus de striation reversible des metaux dans ses rapports avec l'attaque thermique consideree dans sa forme la plus generale. Le diagramme de striation reversible du fer dans des atmospheres H 2 -H 2 O est etabli en fonction de la temperature et de la composition de l'atmosphere. On examine les possibilites de generalisation aux atmospheres sulfurantes et aux surfaces intercristallines.

When a metallic phase comes into contact with a gas phase it is very rare that these two states remain totally indifferent to each other.

Die Erforschung des Vorgangs der Keimbildung bei der Reaktion von Gasen an der Metalloberflache ist erst vor verhaltnismasig kurzer Zeit aufgenommen worden. Keimbildung kommt nachweislich bei zahlreichen Metallen vor und scheint ein allgemein zu beobachtendes Phanomen zu sein. Es wurde zuerst im Falle der Oxydationsreaktionen beschrieben und wurde dann auch bei verschiedenen Reaktionen festgestellt, an welchen Schwefel beteiligt ist. Zuerst werden die Keimbildungsfaktoren, die auf den Eigenschaften sowohl des angreifenden Mittels als auch der Metallstruktur beruhen, untersucht und die Kinetik des Plastikel-Wachstums in ihrem Wesen aufgezeigt, insbesondere der Einflus der Temperatur auf die Kinetik, im zweiten Teil werden die Grunde der Keimbildung bei den Reaktionen der Gase an der Metalloberflache analysiert, wobei besonders die Wirkung der Oberflachendiffusion der regierenden Stoffe berucksichtigt wird. The part played by nucleation with reactions between gases and metals The existence of a nucleation process during reactions of gases on metals has been studied only relatively. It has been shown to occur for numerous metals and the phenomenon appears quite general. First described for the case of oxidation reactions, it has also been found for several sulphuration reaction. The nucleation factors which arise from the properties of both the ambient medium and the structure of the metal are first studied. The characteristics of the kinetics of particle growth are recalled, in particular the effects of temperature on the kinetics. In the second part, an analysis is made of the causes of nucleation in the surface reactions of gases on metals. In particular, the reactants is emphasized.