[An evaluation of fatigue in patients with glioblastoma relapse treated with the combination of irinotecan-bevacizumab]. / Évaluation de la fatigue dans les glioblastomes en récidive traités par l'association irinotécan-bévacizumab.

OBJECTIVE: The combination of irinotecan-bevacizumab is effective in patients with glioblastoma relapse but fatigue is a commonly reported side effect. The objective of this study was to evaluate the level and evolution of fatigue in a series of patients treated with therapeutic combination. PATIENTS AND METHODS: We used two self-evaluation tools to quantify the physical and emotional aspects of this fatigue. The Norris Visual Analog Scale (VAS Norris) and the Multidimensional Fatigue Inventory-20 (MFI) tools were undertaken by 39 patients with glioblastoma relapse treated with irinotecan-bevacizumab, initially before the first cycle and thereafter with each cycle up until tumor progression. RESULTS: Analysis of the results of the VAS Norris scale did not demonstrate an increase in emotional fatigue but did show an increase in physical fatigue that did not reach statistical significance. With regards to the MFI 20 tool, analysis of the results demonstrated a significant increase in general (P=0.0260) as well as physical (P=0.0141) fatigue but there was no difference in the other indices. CONCLUSION: This study demonstrated a progressive increase in physical fatigue in patients with glioblastoma relapse treated with irinotecan-bevacizumab. We suspect that this is as a direct consequence of the treatment. There are however other confounding factors: insidious tumour progression not detected on follow-up imaging or delayed side effects of the initial radiotherapy-chemotherapy.

Source of resistance against Ralstonia solanacearum in fertile somatic hybrids of eggplant (Solanum melongena L.) with Solanum aethiopicum L.

Solanum aethiopicum is reported to carry resistance to bacterial wilt disease caused by Ralstonia solanacearum, which is one of the most important diseases of eggplant (Solanum melongena). These two species can sexually be crossed but the fertility of their progeny is very low. In order to transfer the resistance and improve the fertility, somatic hybrids between S. melongena cv. Dourga and two groups of S. aethiopicum were produced by electrical fusion of mesophyll protoplasts. Thirty hybrid plants were regenerated. When transferred to the greenhouse and transplanted in the field, they were vigorous and showed intermediate morphological traits. Their ploidy level was determined by DNA analysis through flow cytometry, and their hybrid nature was confirmed by examining isozymes and RAPDs patterns. Chloroplast DNA microsatellite analysis revealed that 18 hybrids had the chloroplasts of the eggplant and 12 those of the wild species. The parents and 16 hybrids were evaluated in the field for their fertility and resistance to bacterial wilt using a race 1, biovar 3 strain of R. solanacearum. All hybrids were fertile and set fruit with viable seeds. Their yield was either intermediate or as high as that of the cultivated eggplant. Both groups of S. aethiopicum were found tolerant to R. solanacearum, as about 50% of plants wilted after 8 weeks. The cultivated eggplant was susceptible with 100% of wilted plants 2 weeks after inoculation. All somatic hybrids tested were as tolerant as the wild species, except six hybrids showing a better level of resistance.

Resistance to bacterial wilt in somatic hybrids between Solanum tuberosum and Solanum phureja.

Somatic hybrid plants were produced after protoplast electrofusion between a dihaploid potato, cv. BF15, and a wild tuber-bearing relative, Solanum phureja, with a view to transferring bacterial wilt resistance into potato lines. A total of ten putative hybrids were selected. DNA analysis using flow cytometry revealed that six were tetraploids, two mixoploids, one amphiploid and one octoploid. In the greenhouse, the putative hybrids exhibited strong vigor and were morphologically intermediate, including leaf form, flowers and tuber characteristics. The hybrid nature of the ten selected plants was confirmed by examining isoenzyme patterns for esterases and peroxidases, and analysis of RAPD and SSR markers. Analysis of chloroplast genome revealed that eight hybrids possessed chloroplast (ct) DNA of the wild species, S. phureja, and only two contained Solanum tuberosum ct type. Six hybrid clones, including five tetraploids and one amphiploid, were evaluated for resistance to bacterial wilt by using race 1 and race 3 strains of Ralstonia solanacearum, originating from Reunion Island. Inoculations were performed by an in vitro root dipping method. The cultivated potato was susceptible to both bacterial strains tested. All somatic hybrids except two were tolerant to race 1 strain, and susceptible to race 3 strain. Interestingly, the amphiploid hybrid clone showed a good tolerance to both strains.

Effect of synthetic lipids on apoptosis and expression of alkaline phosphatase in B-lymphocytes: influence on lipopolysaccharide action.

Synthetic lipids were examined for their ability to mimic or to antagonize lipopolysaccharide (LPS) action in murine B-lymphocytes. Several recognized effects of LPS were analyzed: prevention of spontaneous apoptosis, expression of alkaline phosphatase (ALP) and stimulation of proliferation. Three synthetic lipids were used for that purpose: a lipopeptide (compound MTPP) which carries non-hydroxylated fatty acids, and is thus unrelated to LPS, and two glycolipids with hydroxylated fatty acids (compounds D2 and PPDm2-B), structurally related to the lipid A region of enterobacterial and Rhodopseudomonas LPS, respectively. We found that the ability of these lipids to induce LPS-like responses was not correlated with their structural analogy with LPS. Thus, the lipopeptide, MTPP, mimicked LPS in the three activities, whereas the glycolipid, D2, did not. In contrast, the ability of synthetic lipids to block LPS effects was correlated with their structural analogy with LPS. We thus observed that compound D2 selectively blocked LPS-induced ALP expression and that PPDm2-B selectively inhibited LPS-induced prevention of apoptosis. These synthetic lipids could therefore be useful for studying the LPS-mediated signals involved in B-cell activation and apoptosis.

IL-4 inhibits apoptosis and prevents mitochondrial damage without inducing the switch to necrosis observed with caspase inhibitors.

We previously demonstrated that the broad-spectrum caspase inhibitor, zVAD-fmk, totally deviated apoptosis to necrosis in B lymphocytes. We report here that, in contrast with zVAD-fmk, IL-4 protected B cells from spontaneous and from dexamethasone-induced apoptosis and actually maintained cell viability. This was assessed by morphological and biochemical criteria and accompanied by the maintenance of mitochondrial transmembrane potential (DeltaPsiCm) and elevated glutathione (GSH) levels. Under these conditions, zVAD-fmk also totally inhibited apoptosis in thymocytes, but it partly preserved cell viability with a parallel increase in the percentage of cells exhibiting high DeltaPsiCm and elevated GSH levels. Nevertheless, non-rescued cells were deviated to necrosis. Therefore, the pathway leading to either apoptosis or necrosis appears to involve common mitochondrial dysfunctions which could not be reversed by caspase inhibition, suggesting that the pharmacological inhibition of cell death should occur at an earlier stage.

Specific dual effect of cycloheximide on B lymphocyte apoptosis: involvement of CPP32/caspase-3.

Cycloheximide (CHX) is known to stimulate or to prevent apoptosis, according to the cell type used. We found that CHX, in a dose-dependent way, exerted the two opposite effects in B lymphocytes. CHXhigh (2.5 microg/mL) inhibited protein synthesis (>90%) and greatly increased B cell apoptosis but failed to prevent apoptosis induction by dexamethasone (DEX) or dibutyryl-cAMP (dbcAMP), which is in opposition with CHX activity in thymocytes. On the contrary, CHXlow (0.05 microg/mL), modestly inhibited protein synthesis (<15%) and reduced spontaneous as well as drug-induced apoptosis and further augmented the protection conferred by interleukin-4 or lipopolysaccharide. To examine the role of caspases in CHX effects, we used the broad spectrum peptide caspase inhibitor Z-VAD-fmk: it totally abrogated spontaneous as well as drug- and CHXhigh-induced cell death. Apoptosis was associated with CPP32/caspase-3 activation, since cleavage of CPP32/caspase-3 and caspase-3 activity were increased by DEX, dbcAMP as well as by CHXhigh treatment. Meanwhile, caspase-3 activity was reduced by CHXlow treatment. Therefore, CHX exerts opposite effects on B lymphocyte apoptosis which are associated with a dual action on caspase-3 activation.

Induction of apoptosis by dexamethasone in the B cell lineage.

The susceptibility to induction of apoptosis by the synthetic glucocorticoid, dexamethasone (Dex), was analysed at different stages of B cell maturation. Cells of the 70Z/3 pre-B cell line, expressing cytoplasmic mu chains, and LPS-stimulated 70Z/3 cells, expressing surface IgM, were used as a model of differentiation of pre-B cells into immature B cells. Cell proliferation and cell cycle progression were similarly inhibited by Dex (100 nM) in both naive 70Z/3 pre-B cells and in LPS-stimulated 70Z/3 cells. In contrast, Dex failed to affect apoptosis of naive 70Z/3 cells while it increased that of LPS-stimulated 70Z/3 cells. Splenic mature B lymphocytes were highly susceptible to Dex-induced apoptosis since subphysiological doses (5 nM) increased the frequency of apoptotic cells to more than 80%. On the other hand, the treatment of B lymphocytes with LPS, which led to proliferation and differentiation into immunoblasts, decreased the susceptibility to Dex-induced apoptosis. These effects were mediated by the glucocorticoid receptor since they were abrogated by the RU 486 antagonist. The response of B cells to glucocorticoids is thus dependent on their stage of differentiation.

Age-associated modulation of apoptosis and activation in murine B lymphocytes.

We have investigated the influence of age on B-cell responsiveness. The present study showed that the B-cell mitogen, lipopolysaccharide (LPS), similarly stimulated the proliferation of purified B lymphocytes obtained from either young mice (3 months) or old mice (24 months). In contrast, expression of the differentiation marker, alkaline phosphatase (ALP), was about fourfold higher in young mice than in older mice upon stimulation with LPS or with dextran sulfate (DXS) and interleukin-5 (IL-5). The occurrence of apoptosis during aging was then studied: unexpectedly, spontaneous cell death was double in B lymphocytes from young mice compared to older animals. Stimulation with DXS with or without IL-5 rescued B lymphocytes from cell death in young mice but protection decreased with aging, and no longer occurred in 24-month-old mice B cells. Meanwhile, the protective activity conferred by IL-4 was maintained at similar levels throughout aging. However, B cells from old mice were more responsive to apoptosis induction with cycloheximide, dibutyryl cAMP and dexamethasone. Together, the present results indicate an age-associated alteration in apoptosis and activation of B lymphocytes which could contribute to the age-related decline of the immune response.

Inhibition of caspase activity induces a switch from apoptosis to necrosis.

The role of caspases in B lymphocyte cell death was investigated by using two broad spectrum inhibitors of the caspase family, Z-Asp-cmk and Z-VAD-fmk. They totally prevented spontaneous and drug-induced apoptosis and inhibited the CPP32/caspase-3-like activity exhibited by apoptotic cells. However, the suppression of apoptosis was not associated with a long-term increase of cell survival, but conversely, with a switch from apoptotic death to the necrotic form. These results strongly suggest that apoptosis and necrosis share common initiation pathways, the final issue being determined by the presence of an active caspase.

UV irradiation of a B-cell hybridoma increases expression of alkaline phosphatase: involvement in apoptosis.

Expression of alkaline phosphatase (APase) by 7TD1 B-cell hybridoma was amplified by ultraviolet irradiation; cell growth was inhibited and cell death by apoptosis was increased. Irradiation induced high levels of APase activity in cycling as well as in apoptotic cells. In contrast, APase activity faded with time in nonirradiated cells and was no longer expressed in spontaneous apoptotic cells appearing after several days in culture. This was demonstrated by cell morphology, DNA fragmentation, and flow cytometry after simultaneous staining of DNA with Hoechst 33342 and APase with naphthol AS-TR phosphate--fast red RC fluorescent reagent. Levamisole, a specific inhibitor of APase activity, almost totally abrogated apoptosis induced by ultraviolet irradiation at doses that failed to affect 7TD1 cell survival. These data suggest that APase could play a role in the signalling cascade that mediates apoptosis in irradiated cells.

Expression of alkaline phosphatase by a B-cell hybridoma and its modulation during cell growth and apoptosis.

The 7TD1 B-cell hybridoma was found to spontaneously express alkaline phosphatase (ALP), an enzyme which is produced by splenic B lymphocytes once optimally activated. Determination of ALP levels during cell growth and departure to apoptosis showed fluctuations. Following a temporary increase within the first 24 h, enzyme expression was maintained at high levels during the early proliferation stage, and then declined from 3 to 4 days in mid-exponential phase to basal levels at day 6 when living cells were no longer detectable and the apoptotic process was completed. The protein synthesis inhibitor, cycloheximide (1 microg/ml), decreased ALP production while stimulating a strong apoptosis of 7TD1 cells, within 4 h. Aphidicolin (1 microg/ml) maintained ALP production and provoked a release of ALP activity into the surrounding medium; it also induced apoptosis, but with a 24 h delay. Quantification of apoptosis and ALP expression by flow cytometry, after simultaneous staining of DNA with Hoechst 33342 and ALP with naphthol AS-TR phosphate/Fast Red RC fluorescent reagent, revealed cell cycle modulation of ALP expression, its activity increasing as 7TD1 cells progressed from G1 phase into S and G2/M phases of the cell cycle in control as well as in drug-treated cells. Kinetics of drug-induced apoptosis and higher expression of ALP associated preferentially with active cell growth during the prevention stage of apoptosis suggested a possible link between cellular ALP expression and cell survival.

Expression and visualization during cell cycle progression of alkaline phosphatase in B lymphocytes from C3H/HeJ mice.

The expression of alkaline phosphatase (APase) activity by purified B cells from lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice was determined. Optimal APase activity was expressed after costimulation with interleukin-5 and dextran sulfate (DXS), whereas LPS, which is highly effective on B lymphocytes from normal mice, was unable to induce enzyme expression, even in the presence of DXS. The simultaneous determination by flow cytometry of both cellular APase, by using a fluorescent azo dye technique, and DNA content showed that APase was highly expressed by about one-tenth of cells in G1 phase, whereas it was present in more than 50% of cells in S and G2/M phases. The enzyme, as visualized by confocal microscopy after cell sorting on the basis of DNA content, was found to be localized mainly in vesicular structures distributed throughout the cytoplasm in G1 cells. It was distributed in patches and essentially localized at the cell periphery in S cells, whereas clear capping of activity was observed in G2/M cells.

Silica induces apoptosis in macrophages and the release of interleukin-1 alpha and interleukin-1 beta.

Resident adherent peritoneal cells selectively released high amounts of interleukin-1 (IL-1) activity when treated with silica. The use of anti-IL-1 antisera showed that both IL-1 alpha and IL-1 beta were present in supernatants of silica-treated macrophages. In contrast, intracellular IL-1 activity was totally neutralized by anti-IL-1 alpha antibodies and was easily converted into the mature IL-1 alpha form by autolysis in cytoplasmic extracts. Anion exchange chromatography clearly separated the two IL-1 species present in supernatants of silica-stimulated macrophages. Natural IL-1 beta was further characterized by chromatofocalization; it had an apparent isoelectric point, pI, in the range 8.3-8.6. In agreement with previous findings showing that IL-1 beta was released only by apoptotic cells, we have found that silica-treated macrophages underwent apoptosis. This was demonstrated by the characteristic laddering electrophoretic pattern of DNA extracted from silica-treated cells and by the morphology of macrophage nuclei stained with the DNA-specific dye DAPI. In addition, quantification of apoptotic cells was performed by a flow cytometric analysis based on the reduction of cellular DNA content exhibited by apoptotic cells. Treatment of macrophages with silica, therefore, results in an active process that promotes the processing and liberation of IL-1 beta.

Nitric oxide synthase induces macrophage death by apoptosis.

Stimulation processes effective for macrophage (M phi) cytostasis induction also led to a L-arginine-dependent M phi cell death by apoptosis in parallel to nitrite and citrulline production. Resident M phi stimulated with LPS plus IFN-gamma and MDP produced high amounts of nitrite and underwent apoptosis. Inflammatory M phi treated with LPS or IFN-gamma alone produced low levels of nitrite and were not apoptotic, whereas a synergistic effect was observed, the combined treatment leading to high amounts of nitrite and to apoptosis. Primed M phi obtained from concanavalin A-treated mice, after stimulation with LPS alone, released high amounts of nitrite and exhibited the typical ladder pattern of DNA fragmentation of apoptotic cells. In the three cases the L-arginine-dependent nitrite production was inhibited by NG-monomethyl-L-arginine, a competitive inhibitor of NO synthase, which moreover, also inhibited cell apoptosis. These findings and kinetics studies suggest the involvement of NO synthase in apoptosis induction.

Differential stimulation of macrophages for tumor cytostasis and monokine production.

We have investigated whether antitumor activity could be expressed independently of cytokine production. Resident macrophages treated with interferon-gamma (IFN-gamma), lipopolysaccharide (LPS) plus muramyldipeptide (MDP) expressed a cytostatic activity against P815 tumor cells and released interleukin 6 (IL-6) and nitrite but produced neither IL-1 nor tumor necrosis factor (TNF). Thioglycollate-elicited macrophages required only LPS plus IFN-gamma for cytostatic activity which was expressed concomitantly with the release of high levels of TNF, IL-1 and IL-6, whereas C3H/HeJ macrophages produced low levels of monokines and were not cytostatic. LPS, alone, was sufficient for triggering Concanavalin A-primed macrophages leading to a full cytostatic activity, even in C3H/HeJ macrophages that was expressed, for these latter, in the absence of monokine production. TNF did not appear to play a role either in autocrine stimulation of macrophages or in the cytostatic process because anti-TNF antiserum affected neither the cytostatic activity nor the nitrite production.

Interleukin-5 increases the expression of alkaline phosphatase activity in murine B lymphocytes.

Interleukin-5 (IL-5) was shown to enhance, in a dose-dependent fashion, the expression of alkaline phosphatase (APase) activity in splenic B cells stimulated with dextran sulphate (DXS). The potentiating effect of IL-5 was still more evident when assayed in large B cells than in small resting B cells, whereas IL-2, IL-4 and IL-6 were devoid of activity. Concomitant with increased APase expression, cell-cycle analysis by flow cytometry showed that large B cells in the early G1 phase were stimulated by IL-5, in conjunction with DXS, to enter G1B and to progress further through S and G2/M. A phosphorylation-dephosphorylation pathway could, thus, be involved in IL-5 transmembrane signalling.

Flow cytometric analysis of opposite effects of a monokine on proliferation and differentiation of murine B lymphocytes.

A 35,000 mw factor able to replace macrophages (FRM) in the induction of the in vitro antibody response to sheep erythrocytes has been isolated from the supernatant of murine resident peritoneal macrophage cultures. Purified FRM, when added at the outset of cultures, induced B cells to generate an antigen-specific antibody response. The signals provided by FRM in the process of B cell activation were analyzed using a polyclonal model. Cell cycle analysis by multiparameter flow cytometry after acridine orange staining showed that FRM, on its own, did not trigger the transition of B cells from the G0 to the G1 stage of the cell cycle. In addition, FRM affected neither the basal intracellular free calcium level ([Ca2+]i) nor the rapid increase in [Ca2+]i induced by crosslinking of membrane immunoglobulin (mIgM) with anti-mu antibodies. In parallel with its positive effect on B cell differentiation, FRM markedly reduced both proliferation and cell cycle progression of B cells stimulated with anti-mu plus interleukin 4 (IL-4). Indeed, the addition of FRM to such cultures led to a preferential accumulation of cells in the early G1 compartment of the cell cycle and to a decreased frequency of cells in all other phases including G1B, S and G2/M.

Defective production of interleukin 6 by macrophages from C3H/HeJ mice: differential stimulation of interleukin 1 and interleukin 6 induction.

Resident macrophages from lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice, in contrast with macrophages from other mouse strains, produced neither interleukin 6 (IL-6) nor interleukin 1 (IL-1) spontaneously. The stimulation of C3H/HeJ macrophages with poly(I:C), LPS or, to a lesser extent, muramyl dipeptide (MDP), induced the production of both cytokines. High levels of intracellular IL-1 activity were produced which were not released in surrounding media unless silica was added to stimulated cells. On the other hand, IL-6 was secreted in the absence of any additional stimulus, hence also in the absence of extracellular IL-1. The kinetics of IL-1 and IL-6 production by LPS-stimulated macrophages were studied. Intracellular IL-1 produced by stimulated C3H/HeJ macrophages reached the levels produced by macrophages from C3H/HeN mice. IL-6-induced secretion, however, was about 5-fold less important than in C3H/HeN macrophages, suggesting a quantitative defect rather than an intrinsic defect in IL-6 production.

Macrophages from C3H/HeJ mice require an additional step to produce monokines: synergistic effects of silica and poly(I:C) in the release of interleukin 1.

Resident macrophages from C3H/HeJ mice, in contrast with those of other strains of mice such as BDF1 mice, did not release a 35 kD m.w. factor having macrophage replacing activity (FRM) or interleukin 1 (IL-1) when, respectively, cultured alone or in the presence of silica. C3H/HeJ macrophages were nevertheless capable of producing an intracellular IL-1-like activity. In addition, after a two-step activation process, macrophages from BDF1 mice spontaneously released IL-1, whereas silica was required to induce the release of IL-1 from similarly treated C3H/HeJ macrophages. Such in vivo primed and in vitro stimulated macrophages failed to release FRM. In contrast, poly(I:C) was able to induce the release of FRM by C3H/HeJ macrophages but not that of IL-1; moreover, the addition of silica to poly(I:C)-stimulated cells led to an IL-1 release similar to that obtained with normal mice treated with silica alone. Since poly(I:C) is able to elicit the production of interferons (IFN), the involvement of IFNs was investigated in poly(I:C) activity. Neither IFN-alpha/beta nor IFN-gamma, when used alone or in the presence of silica, could induce the release of IL-1 by C3H/HeJ macrophages. In addition, antibodies to IFN-alpha/beta and IFN-gamma were unable to affect the poly(I:C) and silica induced release of IL-1. Thus, the signal provided by poly(I:C) does not appear to be mediated by IFN(s).

Increased expression of alkaline phosphatase activity in stimulated B lymphocytes by muramyl dipeptide.

We have recently shown that the synthetic immunomodulator muramyl dipeptide (MDP) acts on murine B lymphocytes. It synergizes with interleukin 2 and interleukin 4 to stimulate, respectively, the differentiation and the proliferation of B cells. In the present study, MDP was shown to increase the proliferation of B cells stimulated by lipopolysaccharide (LPS). Moreover, the expression of alkaline phosphatase activity induced by LPS was markedly enhanced by MDP. These effects were time- and dose-dependent. The present report suggests that the biochemical mechanism by which MDP exerts its effects may involve protein phosphorylation-dephosphorylation pathways.