Recent data from the literature together with personal results strongly suggest that multidrug resistance phenotype is overwhelming the sole expression of P170 glycoprotein efflux pump. Morphological alterations have been put in evidence in MDR cells after transmission and scanning electron microscopy. They include presence of osmiophilic vesicles and modifications of nuclear and nucleolar chromatin. Biological characteristics include the hypersecretory pattern of lysosomal enzymes from MDR cells. Such a fact could be more or less related to the increased occurrence of mdr1 RNA in metastasis, especially in breast cancers, compared to primary tumors. If the P170-mediated efflux is one of the key mechanism of MDR, a decreased influx of anticancer drugs cannot be excluded. Liposomes, for instance made of cardiolipin, are thus able to increase the intracellular drug uptake of vinblastine without any action upon efflux mechanism.

Calcium channel inhibitors, such as verapamil, have been identified as having the ability to modulate the multidrug-resistant (MDR) phenotype due to overexpression of P-glycoprotein (Pgp). We have studied the effect of verapamil on Pgp expression levels in a cell line originating from acute myeloblastic leukemia and resistant to adriamycin, K562/ADR. In this line, the addition of 15 microM verapamil in the culture medium gives a 3-fold decrease of Pgp expression after 72 hours of treatment. Similar results have been obtained for two other MDR cell lines, which suggest that this phenomenon is not specific of a single model. The level of mdr1 mRNAs is decreased in the presence of verapamil (with a maximum effect obtained at the 24th hour), which suggests that the mechanism of action of verapamil is transcriptional and/or post-transcriptional. We have also studied the effect of verapamil on the level of expression of mdr1 mRNAs in non-drug selected cells such as the HEL line (human acute myeloblastic leukemia) and the parental K562 line, which present a very low level of expression of Pgp, detectable only by PCR. In these lines, verapamil treatment has no effect on the level of expression of mdr1 mRNAs. The effect of verapamil is therefore restricted to drug-selected lines presenting high levels of Pgp expression. The impact of the negative regulation of Pgp expression on the MDR phenotype has been studied in the K562/ADR line. When the cells are treated for 72 h by verapamil, there is a decrease of resistance and an increase of intracellular accumulation of anticancer agents such as daunorubicin or vinblastine. Negative regulation of Pgp expression appears therefore as a possible strategy for MDR phenotype reversal. The effect of verapamil, whose molecular mechanism of action is being studied, could constitute a basis for this strategy.

Chinese hamster lung cells resistant to 9-OH-ellipticine (DC-3F/9-OH-E) present a complex phenotype. These cells, which are about 150-fold resistant to 9-OH-E, display a cross-resistance to other topo-II inhibitors, such as m-AMSA or VP-16, which stabilize the cleavable complex. In addition, these cells display also a cross-resistance to suramin, which is also a topo-II inhibitor, but does not stabilize the cleavable complex. Finally, DC-3F/9-OH-E present a multidrug-resistant phenotype (MDR) which confers a cross-resistance to natural products such as actinomycin D, taxol or vincristine, due to a decrease of cellular accumulation of these drugs. Analysis of expression of the genes encoding topo-II alpha and beta, and the evaluation of both enzyme forms by immunoblotting, revealed that DC-3F cells contained about 20-fold less of the beta form than of the alpha form. The alpha form was decreased by about 4-5-fold in DC-3F/9-OH-E, whereas the beta form became undetectable. Purification and characterization of topo-II activities in sensitive and resistant cells is presently in progress. Analysis of the expression of pgp1, 2, 3 genes, involved in the MDR phenotype in hamster, by Northern blotting or by immunoblotting, has shown that the MDR phenotype in DC-3F/9-OH-E cells is due to the overexpression of pgp1 gene. In these cells, pgp3 expression is positively regulated by myc oncogene expression. Overexpression of the myc gene is followed by an overexpression of the pgp3 gene and is associated to a reversal of the MDR phenotype.

Antimitotic chemotherapy and/or radiation therapy can induce a premature ovarian failure in women. The improvement of the prognosis of cancer and the increasing in long-term survival mean that preservation of fertility should be considered before initiating therapy. An embryo cryopreservation can be proposed if the circumstances allow that possibility. Ten young women were included in our program and benefited from an oocyte retrieval before cancer therapy. Nine of them had an embryo cryopreservation, and one without partner an oocyte cryopreservation. Three patients had an embryo replacement without success, and in one case, a spontaneous full-term pregnancy was obtained after ovarian detransposition through coelioscopy. In the future, oocyte cryopreservation could appear a more suitable answer. Actually, oocyte donation with estrogen and progesterone replacement therapy gives good results (in our experience, 23.2 per cent of ongoing pregnancies per transfer). Nevertheless, after treatment against cancer, a study of the uterus with its arteries, and a particular adaptation of the treatment are necessary because of the risks of tissue damage impairing the embryo implantation. Indeed, in fifteen patients included in this group, eight women had fourteen transfers unfortunately without success. Consequently, the seven other women underwent complementary examinations. Two embryos were replaced in one patient with a more adjustable treatment allowing a full-term pregnancy.

Pregnancy coexisting with evolutive malignant blood disease (Hodgkin's disease, acute leukemia, non-Hodgkin's lymphoma, chronic myeloproliferative disorder) is a therapeutic dilemma because of possible adverse reactions associated with the use of cytostatic agents. Therapeutic abortion, when needed, must be proposed only after a careful evaluation of the following parameters: the emergency of treatment, the prognosis of the disease, the term of pregnancy, the risks of therapy for the foetus and the mother, and the psychosocial context. From the clinical data published so far, the teratogenicity of cytostatic drugs seems to be minimal after the second trimester, and the outcome of pregnancy is often favorable, whatever the hemopathy. Radiation therapy must be used very cautiously and only in supradiaphragmatic areas. An overview of specific problems is done for each category of malignant blood disease.

The triazinoaminopiperidine derivative S 9788 is a new multidrug resistance modulator. The modulating activity of S 9788, comparatively to those of verapamil and the combination of S 9788 and verapamil, was demonstrated on the human leukemic T cell line CCRF-CEM resistant (about 6000 fold) to vinblastine using Microculture Tetrazolium Assay. S 9788 at 5 microM, strongly potentialized the cytotoxic activity of vinblastine but the reversion of resistance remained partial. Verapamil and the combination S 9788-verapamil, tested at equimolar concentrations, were respectively 1000 and two times less active than S 9788 alone. The impact of S 9788, verapamil and their combination on the cytological modifications bound to vinblastine resistance of CEM cells was evaluated by multiparametric quantitative cytological analysis (21 nuclear parameters measured) using a SAMBA 2005 cell image processor. Treatments with the different modulators, in absence or in presence of vinblastine, had no significant effects on the morphology of sensitive CEM cells. On vinblastine resistant CEM cells, S 9788 and the combination S 9788-verapamil induced significant cytological modifications. These modifications were characterized by a partial reversion of some parameters (more specifically nuclear texture parameters) to values close to those observed in parental sensitive cells and permitted an automatic classification of these treated resistant cells in cells of "sensitive" type with a percentage superior to 50%. In conclusion, the reversion of resistance induced by S 9788 on CEM cells resistant to vinblastine does not fit only with a biological phenomenon like the efflux of cytotoxic agents but is associated with a set of cellular alterations involved in multidrug resistance.

Ellipticines are intercalating planar polycyclic aromatic molecules that display antitumor activity. The cytotoxicity of these compounds is related to the presence of an hydroxy group at position 9 of the pyridocarbazole ring system and to their interaction with DNA topoisomerase II. The ability of 13 ellipticine derivatives to stabilize the topoisomerase II-DNA covalent complex in vitro is reported. The following observations emerge from our structure-activity relationship study: i) the hydroxy group at position 9 is essential for stabilizing the covalent complex, ii) the replacement of the methyl group at position 5 by an ethyl group (EPC) enhances the complex stabilization. The interaction of EPC and three other ellipticine analogues with DNA shows that the covalent complexes which are most stable have the lowest drug-DNA binding constants. In addition our study suggests that ellipticines induce covalent complex stabilization by a cooperative mechanism. A model is proposed to explain this stabilization by ellipticines. This study supports the idea that topoisomerase II is the primary target involved in the mechanisms of action of ellipticines.

S9788, a triazinoaminopiperidine derivative, is a new multidrug resistance (MDR) modulating agent. S9788 activity was investigated on 12 tumoral cell lines, either sensitive or resistant, with respect to different cytotoxic agents: adriamycin (ADR), daunorubicin (DNR), viscristine (VCR) and vinblastine (VLB). S9788 is 1.5 to 30 times more active than verapamil and 1.2 to 119 times more active than cyclosporin, depending on both the cell line and the antitumoral agent. Reversion of resistance to ADR was nearly complete in K562R at 5 microM S9788 (F Res = 30; F Rev = 20). In MCF7/ADR cell line, highly resistant to ADR, S9788 (1 microM) partially reversed the resistance (F Res = 917; F Rev = 110). S9788, when associated with either ADR or vinca-alcaloïds, had a slight effect on ovarian carcinoma (OVCCR1, NIHOVCAR3, SKOV3, IGROV1), sarcoma (SARCCR2) and breast adenocarcinoma (CAL51, CAL85-1/2) cell lines which poorly expressed P glycoprotein (F Rev = 1-3). In K562R cells, S9788 (5 microM) restored DNR accumulation (measured by flow cytometry) to a level similar to that measured in sensitive cells K562S. A novel method of microspectrofluorimetry showed that S9788 modified the kinetic and the intracellular distribution of cytotoxic agent, leading to its accumulation in resistant cell nuclei. Concomitant incubation of S9788 and cytotoxic agent, followed by a postincubation with S9788 alone, significantly increased MDR reversion. Therefore, S9788 should be used as an adjuvant of polychemotherapy against tumors displaying MDR phenotype.

Birth defects registries have been established following the thalidomide epidemic in the early sixties. A first objective of registries is to monitor the frequency of specific malformations in order to detect as early as possible any variation caused by the introduction of a new teratogen in the environment. After 30 years not any new teratogen has been identified by this. It appears that the predictive value of alarms generated by surveillance is extremely low and that resources are insufficient to investigate most of warnings. However, registries have been useful to test specific hypotheses i.e. the effect of iatrogenic exposures. Three examples are given, showing the necessary characteristics of registries: topical treatment with tretinoin, chorionic biopsy and cancer treatment.

During the follow-up of patients treated for squamous cell carcinoma, dentists have to look for recurrences and metastases. They play also a very important role in the prevention and treatment of the different treatment induced oral sequelae. Special attention is drawn to the postradiation complications like mucositis, xerostomia, radiation caries, trismus and osteoradionecrosis. Despite the fact that no universal accepted protocols are available, the author presents some therapeutic procedures, based on the review of the literature and clinical experience. The importance of a long time follow-up is underlined.

Thirty-five years after its first use in breast cancer, chemotherapy has become a major management tool. In locally advanced and inflammatory forms, chemotherapy is administered preoperatively giving a 5-year survival rate of 50 to 70%. As an adjuvant, both for N+ and N-forms, and both before and after menopause, chemotherapy improves overall and relapse-free survival rate. Chronicity is thus possible in metastatic cases with objective responses above 70% and important progress in patient comfort. In addition to alkylizing agents, 5-fluoro-uracil, anthracyclines and methotrexate used in the traditional combinations, new cytostatic agents, vinorelbine and taxoid agents, now in phase I and phase II trials have demonstrated their effectiveness in breast cancer. Medullar growth factors, and autografting with bone marrow and more recently circulating stem cells have made it possible to intensify the doses (although to what precise level have yet to be established.

Evaluate the different quality of life parameters in treated breast cancer patients.

This review presents different aspects of oncological pharmacokinetics and emphasizes the clinical applications. Pharmacodynamics, pharmacokinetics in phase I trials, search for kinetic interactions are approached.

Over the last 30 years, considerable progress have been made in developing methodologies to analyze unwanted drug effects. The aim of this study is to explain the French method utilized to impute the side effects of a drug. An example of anthracycline cardiotoxicity will be discussed.

There is a large field of use for cisplatin and its derivatives in the treatment of human malignancies. The nephrotoxicity is their most important use-limiting factor. The aim of this work has been to study comparatively the cisplatin and a new molecule, the oxaliplatin on primary culture of proximal tubular cells of rabbit kidney. Several markers, functional, enzymatic and biochemical have been evaluated after exposure to platinum's derivatives. The results indicates that their toxic effects are exerted on DNA and proteins synthesis, and for the cisplatin on the glucose uptake. Oxalyplatin's effect on DNA synthesis seems to be more effective, but induced a more progressive cytotoxicity. The lipids peroxidation's role with abnormalities of glutathione dependent detoxication system of the cell is possible. In conclusion, oxaliplatin seems to have a pharmacological effect more powerful than cisplatin. Its low dose effect ratio seems to promise greater safety in its use.

Over the past decade, DNA topoisomerase I and II appeared to be the targets of some antitumor agents: CPT-11 and Topotecan derived from Camptothecin which interact with topoisomerase I; Actinomycin D, Adriamycin and Daunorubicin, Elliptinium Acetate, Mitoxantrone, Etoposide and Teniposide, Amsacrine which interact with topoisomerase II. The multiple functions of these enzymes are important as they play a role during replication, transcription, recombination, repair and chromatine organisation. Particularly, they relax torsional constraints which appear when intertwined DNA strands are separated while replication fork or RNA polymerases are moving. To some extent, topoisomerase I and II are structurally and functionally different. Moreover, topoisomerase I is not indispensable for a living cell whereas topoisomerase II is. Drug-topoisomerase interaction which probably leads to antitumoral effect of the compounds studied in this review is not a trivial inhibition of the enzyme but rather a poisoning due to stabilization of cleavable complexes between the enzyme and DNA. These stabilized complexes are likely to induce apoptosis-like programmed cell death, which is characterised by DNA fragmentation. However, it appears that it is the collision of the replication fork with the drug-stabilized cleavable complex that is responsible for the cytotoxicity of the drug: poisoning of topoisomerases by antitumor agents leads to a new concept of "dynamic toxicity". Although they interact with a common target, topoisomerase II poisons have differential effects on macromolecules syntheses, cell cycle and chromosome fragmentation; a few compounds may produce free radicals. Because of these differential effects in addition to quantitative and qualitative variations of stabilized cleavable complexes, in particular DNA sequences on which topoisomerase II is stabilized, these antitumor agents do not resemble each other. Cellular resistance to topoisomerases poisons results of two principal types of alteration: target and/or drug transport modification. Decreased ability to form the cleavable complex in resistant cells may be the consequence of both decreased amount of topoisomerase or altered enzyme. On the other hand, overexpression of membrane P-glycoprotein, which pumps drugs out of the cell by an energy dependent process provokes a decreased accumulation of these drugs. Cross resistances to other drugs are mainly under control of these two different mechanisms of resistance. A complete knowledge of their individual effects and mechanisms of resistance would allow a better clinical use of topoisomerases poisons, especially when administered in combination chemotherapy.

In recent years, chemotherapy and radiations for cancer patients has become increasingly successful, and sustained remissions have been achieved. However, in young men, most of the current therapies still presently induce temporary or permanent sterility without any means of prediction. The present paper largely based on data accumulated over two decades at CECOS Paris-Bicêtre reassess the clinical role of semen cryopreservation from young men with cancer before chemotherapy and/or radiotherapy. Recent use of assisted reproduction technologies with pretherapy cryopreserved specimens (including semen of poor quality) has provided a growing number of pregnancies. These new data strongly reaffirm that semen cryopreservation should be offered to all men diagnosed with cancer since it presently provides the only reasonable chance of establishing a pregnancy after therapy.