Cytokine‐regulated urokinase‐type‐plasminogen‐activator (uPA) production by human breast fibroblasts in vitro

It has been shown that, in breast stroma, urokinasetype plasminogen activator (uPA) mRNA is predominantly expressed by myofibroblasts located at the invasive areas of the tumor. To examine which factors present in a tumor environment are candidates responsible for the induction of these uPAproducing myofibroblasts, we studied in vitro the capacity of a paired panel of normal and tumorderived human breast fibroblasts to produce uPA protein and the myofibroblast marker smoothmuscleactin (SMA) in response to various cytokines implicated in the process of tissueremodeling during malignant transformation.We found that fibroblasts produced increased amounts of uPA protein after exposure to aFGF, bFGF, EGF, PDGFBB, and IFN, were unaffected in this respect by IL6, MCSF, GMCSF and Oncostatin M, and produced decreased amounts of uPA protein after exposure to IL1, TNF, IGFI, and IGFII. None of these cytokines were able to induce a striking increase in the fraction of SMApositive fibroblasts. On the other hand, 25pM TGF₁ increased the fraction of SMApositive fibroblasts 5fold in both normal and tumortissuederived fibroblasts. Nonetheless, the normalderived fibroblasts were unaffected in their uPAproducing capacity by TGF₁, and the tumorderived fibroblasts produced decreased amounts of uPA protein after exposure to this cytokine, implying that at least in vitro the myofibroblast phenotype is not a prerequisite for the production of uPA by human breast fibroblasts. In addition, we established that the basaluPAproduction of both normal and tumorderived fibroblasts was increased by autocrinely produced bFGFlike activity, and that the basaluPAproduction of at least the normalderived fibroblasts was decreased by autocrinely produced IGFlike activity.Altogether, our data suggest an active role for fibroblasts in the process of uPAdirected breast tumor proteolysis.     

Quantification of thrombospondin-1 secretion and expression of αvβ3 and α3β1 integrins and syndecan-1 as cell-surface receptors for thrombospondin-1 in malignant glioma cells

Malignant glioma cells secrete thrombospondin-1 (TSP-1) which participates in the motility of glioma cells, and binds to cell surface v3 and 31 integrins, and syndecan-1. This study evaluated the amount of TSP-1 secretion from malignant glioma cells, and the expression of v3 and 31 integrins, and syndecan-1. The amounts of TSP-1 in the supernatants from 10 malignant glioma cell lines and eight non-glioma malignant tumor cell lines were measured by enzyme-linked immunosorbent assay. Expression of v3 and 31 integrins, and syndecan-1 were examined by flow cytometry. The amounts of TSP-1 secreted by malignant glioma cells were 43 to 2431 ng/1 × 10⁶ cells/24 h (mean ± SD=626 ± 792). Seven of 10 glioma cell lines secreted more than 100 ng of TSP-1 and three of these cell lines secreted more than 1 g. Seven of eight non-glioma cell lines secreted less than 100 0ng of TSP-1. All glioma cell lines expressed 31 integrin and syndecan-1, and seven of 10 glioma cell lines expressed v3 integrin. Treatment of the glioma cell lines with TGF-2 did not change the expression of v3 integrin. These results suggest that malignant glioma cells secrete high levels of TSP-1, which may be important in the migration of glioma cells via interactions with v3 and 31 integrins, and syndecan-1.     

Multiple actions of synthetic ‘progestins’ on the growth of ZR-75-1 human breast cancer cells: Anin vitro model for the simultaneous assay of androgen,progestin, estrogen,and glucocorticoid agonistic and antagonistic activities of steroids

This study was designed to assess the multiple steroid receptor mediated activities of a series of synthetic progestins on breast cancer cell growth, using the human ZR-75-1 cell line which possesses functional estrogen (ER), androgen (AR), and glucocorticoid (GR) receptors as well as progesterone (PgR) receptors. Four 17-hydroxyprogesterone derivatives (chlormadinone acetate, CMA; cyproterone acetate, CPA; medroxyprogesterone acetate, MPA; and megestrol acetate, MGA) and two 19-nortestosterone derivatives (norethindrone, NRE, and norgestrel, NRG) were thus investigated.Based on the requirement of estrogens for PgR-mediated antiproliferative effects and the reversal of PgR-mediated action by insulin, it was found that although all progestins could inhibit ZR-75-1 cell growth through the PgR at low concentrations, the relative contribution of this receptor in cell growth control is highly variable between compounds. The quantitative importance of PgR-mediated inhibition of cell proliferation was inversely related to the amplitude of the androgenic effects induced by the compounds, the AR-mediated effects increasing in the order CPA < MGA < CMA < NRE < NRG < MPA. The specificity of these androgenic effects is further supported by their reversal upon addition of the antiandrogen hydroxyflutamide. In addition, the 17-hydroxyprogesterone derivatives, but not the 19-nortestosterone derivatives, had glucocorticoid activities at high (micromolar) concentrations, as shown by reversal of growth inhibition by the antagonist RU486 in the presence of saturating concentrations of 5-dihydrotestosterone. All progestins tested, except MPA and NRE, also had some antiglucocorticoid activity, NRG being the most potent in this respect. Finally, NRE and NRG exerted a marked mitogenic effect in estrogen-free medium which was clearly mediated through the ER as shown by the competitive reversal of their action by the steroidal antiestrogen EM-139.The present results show that growth measurements of the human breast cancer cells ZR-75-1 permit, with the appropriate steroid additions, the assay of progestin, androgen, estrogen, and glucocorticoid agonistic as vell as antagonistic activities of test compounds. The present study shows, somewhat surprisingly, that while the AR is almost completely responsible for the action of MPA at low concentrations, the majority of the action of NRE, NRG, and MGA is also exerted through AR, while the androgenic action of CPA plays a lower role in the growth inhibition induced by this compound. Such a model should be of great help in designing more specific steroid drugs and in better understanding the role of the different steroid classes which can be used to control the growth of hormone-sensitive cancer. The present data also indicate that progestin is an inappropriate name for MPA, NRE, NRG, MGA, CMA, and CPA, which all possess other and sometimes more potent steroidal activites than those related to interaction with the progesterone receptor.Abbreviations CMA chlormadinone acetate [17-acetoxy-6-chloropregna-4, 6-dien-3, 20-dione] - CPA cyproterone acetate [17-acetoxy-6-chloro-1,2-methylene-pregna-4, 6-dien-3, 20-dione] - DEX dexamethasone [9-fluoro-11, 17, 21-trihydroxy-16-methyl-pregna-1, 4-dien-3, 20-dione] - DHT 5-dihydrotestosterone [17-hydroxy-5-androstan-3-one] - E₂ estradiol [estra-1, 3, 5 (10)-trien-3, 17-diol] - EM 139 [N-n-butyl-N-methyl-11-(16-chloro-3, 17-dihydroxyestra-1, 3, 5 (10)-triene-7-yl) undecanamide] - MGA megestrol acetate [17-acetoxy-6-methylpregna-4, 6-dien-3, 20-dionel] - MPA medroxyprogesterone acetate [17-acetoxy-6-methylpregn-4-en-3, 20-dione] - NRE norethindrone [17-hydroxy-19-nor-17-pregn-4-en-20-yn-3-one] - NRG norgestrel [13-ethyl-17-hydroxy-18, 19-dinor-17-pregn-4-en-20-yn-3-one] - OHF hydroxyflutamide (SCH 16423) [, , -trifluoro-2-methyl-4-nitro-m-lactotoluidide] - R1881 methyltrienolone [17-hydroxy-17-methyl estra-4, 9, 11-trien-3-one] - R5020 promegestone [17, 21-dimethyl-19-norpregna-4, 9-dien-3, 20-dione] - RU486 [17-hydroxy-11-(4-dimethylaminophenyl)-17-(1-propynyl)-estra-4, 9-dien-3-one] - triamcinolone acetonide [9-fluoro-11, 21-dihydroxy-16, 17(1-methylethylidenebis oxy) pregna-1, 4-dien-3, 20-dione]     

New approach to metabolism of 5′-deoxy-5-fluorouridine in humans with fluorine-19 NMR

Summary The metabolism of 5-deoxy-5-fluorouridine (5dFUrd), an antitumor fluoropyrimidine, has been investigated in human biofluids (blood, plasma, urine) using a new method: fluorine-19 NMR spectrometry. This method allows direct study of the biological sample and simultaneous identification of all the fluorinated metabolites. In the blood of a patient treated with 5dFUrd during a 6-h continuous perfusion, we observed unmetabolized 5dFUrd, 5-fluorouracil, 5,6-dihydrofluorouracil, and another metabolite which has not previously been reported -fluoro--alanine. The two major metabolites in urine are unmetabolized 5dFUrd and -fluoro-alanine.     

Doxorubicin-induced hair loss in the Angora rabbit: a study of treatments to protect against the hair loss

Summary An animal model for anticancer drug-induced hair loss has been developed using the Angora rabbit given i.v. doxorubicin, 2 mg/kg, twice weekly for 3 weeks. There was a 167% increase in the weight of hair collected by grooming between weeks 2 and 5, and a 72% inhibition of new hair growth at week 6 compared with non-treated animals. The hairs that grew in the doxorubicin treated rabbits did so at the same rate as in non-treated rabbits and appeared normal by light microscopy. Topical application of dimethylsulfoxide (DMSO), of 10% -tocopherol in DMSO, of 0.5% naphthazoline hydrochloride in DMSO, of 0.1% fluocinolone acetonide in a propylene glycol base and local hypothermia did not provide any protection against doxorubicin-induced hair loss. Angora rabbits fed an -tocopherol-deficient diet for 6 weeks showed decreased hair growth compared with animals fed a normal diet or a diet supplemented with 100 mg -tocopherol acetate twice a week for 6 weeks. Some rabbits fed the -tocopherol-deficient diet died when given doxorubicin. Rabbits fed the -tocopherol-supplemented diet showed evidence of protection against doxorubicin-dependent inhibition of new hair growth.     

Retinoid Receptors in Human Breast Carcinoma: Possible Modulators of in Situ Estrogen Metabolism

Retinoid receptors (retinoic acid (RARs) and retinoid X (RXRs) receptors) were immunolocalized in 32 human invasive ductal breast carcinomas. These findings were correlated with clinicopathological parameters to study their biological significance in breast carcinoma. Retinoid receptor immunoreactivity, except for RXR, was detected in the nuclei of carcinoma cells. Percentage of positive cases were RAR 81%, RAR; 6%, RAR; 28%, RXR; 81%, and RXR; 59%. A significant correlation was detected between RAR labeling index (LI), and RXR LI (r=0.667, p<0.001). Results from immunoblotting performed in three cases were consistent with those of immunohistochemistry. There was a significant correlation between RAR LI and 17-hydroxysteroid dehydrogenase (17-HSD) type 1 immunoreactivity (p<0.05). A significant correlation was also detected between RAR (r=0.413, p=0.019) or RXR (r=0.429, p=0.014) LI, and estrogen receptor (ER) LI. In T-47D breast cancer cells, which express RAR, RXR and ER, 17-HSD reductive activity increased 1.76-fold (p<0.001), five days following treatment with 10nM retinoic acid. These data suggest that retinoid receptors modulate various effects of retinoids, including estrogen metabolism in human breast carcinomas.     

Growth inhibitory effect of recombinant α and β interferon on human glioma cells

Summary Growth inhibitory activity of recombinant and interferon on two human glioma cell lines, EFC-2 and KE cells, was determined by two different growth assays. Recombinant interferon showed slight growth inhibitory effect on EFC-2 cells at day 3, and maximum inhibition was seen on day 6 with an ID50 of 50 U/ml. Recombinant interferon showed no significant growth inhibition at any concentration. KE cells were resistant to both recombinant and interferon. The growth inhibitory activity of recombinant interferon on EFC-2 cells was not blocked by recombinant interferon, although recombinant and interferons shared same receptors on EFC-2 cells. Addition of DFMO (-difluoromethylornithine) to interferon in the media showed additive effect rather than synergistic effect in growth inhibition of glioma cells. Out of 7 glioma cell lines tested, 4 showed heterogeneous sensitivity to recombinant interferon, and all were resistant to recombinant interferon. These results suggest differential sensitivity of EFC-2 cells to recombinant interferon, as well as a heterogeneous sensitivity to recombinant interferon among different glioma cell lines.     

Tumor necrosis factor-alpha induces interleukin-6 production via extracellular-regulated kinase 1 activation in breast cancer cells

Interleukin-6 (IL-6) and interleukin-11 (IL-11) are frequently produced by breast cancer cells. These interleukins promote osteoclast formation and may mediate osteolysis at the site of breast cancer bone metastases. Transforming growth factor- (TGF-), tumor necrosis factor- (TNF-) and interleukin-1 (IL-1) up-regulate IL-6 and IL-11 production in a cytokine-dependent fashion in breast cancer cells, but very little is known about their intracellular signaling pathways in breast cancer cells. To study TGF-, TNF- and IL-1 regulation of IL-6 and IL-11 production in human MDA-MB-231 breast cancer cells, we established single cell clones stably expressing dominant negative (DN) forms of the mitogen-activated protein kinases p38 (p38/AF) or ERK1 (ERK1K71R). We show here, that while basal, TGF- and IL-1 induced IL-6 production was similar in parental cells and in pcDNA3 control, ERK1K71R and p38/AF clones, TNF- induced IL-6 production was blunted in the ERK1K71R clones. TGF- and IL-1, but not TNF-, induced IL-11 production in parental MDA-MB-231 cells. Similar findings were detected in clones stably expressing p38/AF and ERK1K71R, which did not change basal IL-11 production either. In conclusion, TNF- induced IL-6 production is mediated via ERK1 activation in MDA-MB-231 cells. These observations may be helpful in designing new anti-osteolytic therapies.     

Overexpression of the p73 gene is a novel finding in high-risk B-cell chronic lymphocytic leukemia

The p73 protein shares structural and functional similarities with thetumour-suppressor p53, but its role in neoplastic transformation is unknown.Alternative splicing leads to the expression of at least nine p73 C-terminalmRNA splice variants (, , , , , , ,1, ). In this survey, we analyse the expression of p73 byreal-time quantitative RT–PCR, its known C-terminal variants with anRT–PCR-Southern technique and by Western blot in samples of 51 patientswith B-CLL, normal B lymphocytes from eight individuals, and fivehaematopoetic cell lines. p73 protein expression positively correlatedwith higher risk B-CLL stages (P = 0.046). Total p73 mRNAexpression was higher (P = 0.01) and p73 protein morefrequently detected (P = 0.008) in B-CLL compared with normalCD19+–B-lymphocytes. p73 C-terminal mRNA variants were expressed bothin B-CLL and in normal B-lymphocytes, but their expression was biased sincethe (P = 0.041), the (P <0.001), and the variant (P = 0.033) prevailed in normalB-lymphocytes. In summary, we conclude that the accumulation of p73, theexpression pattern of particular p73 variants and its link to progression mayplay a distinct role in the molecular pathology B-CLL.     

Glucocorticoids and androgens up-regulate the Zn-α2-glycoprotein messenger RNA in human breast cancer cells

Summary We have studied the hormonal regulation of the gene encoding Zn-₂-glycoprotein (Zn-₂-gp), a human protein with a high degree of amino acid sequence similarity to class I histocompatibility antigens that is produced by a specific subset of breast carcinomas. Northern blot analysis revealed that dexamethasone and 5-dihydrotestosterone strongly induced the accumulation of Zn-₂-gp mRNA in T-47D human breast cancer cells. Furthermore, the effect of these two hormones was shown to be additive, since the combination of both hormones produced a stimulation of Zn-₂-gp mRNA of at least 3-fold over that produced by either hormone alone. By contrast, the addition of 5-dihydrotestosterone, 17-estradiol, or progesterone failed to induce the expression of Zn-₂-gp. The stimulatory effect of glucocorticoids and androgens on Zn-₂-gp expression was produced in a time and dose dependent manner, without significantly affecting the cell proliferation rate. A time-course study demonstrated that the induction of Zn-₂-gp mRNA by androgens and glucocorticoids reached a level of 4 or 3.2-fold over the untreated control after seven days of incubation in the presence of a 10^–7 M concentration of 5-dihydrotestosterone or dexamethasone, respectively. A dose-response study showed that as little as 10^–11 M of 5-dihydrotestosterone or dexamethasone produced an accumulation of Zn-₂-gp mRNA of 2.4 or 2.1-fold over the control, respectively. On the basis of these results, we propose that Zn-₂-gp may be useful as a biochemical marker of breast carcinomas with a specific pattern of hormone responsiveness in whose development glucocorticoids and/or androgens may play a significant role.     

Synergistic enhancement by interleukin-1 α of cisplatin-mediated antitumor activity in RIF-1 tumor-bearing C3H/HeJ mice

Administration of interleukin-1 (IL-1 ) plus certain cytotoxic drugs causes substantially greater clonogenic tumor-cell kill and tumor-regrowth delay than does treatment with either agent alone. IL-1 itself has little effect on tumor growth despite its ability to induce acute hemorrhagic necrosis, restrict tumor blood flow, and cause microvascular injury in a variety of murine model systems. To investigate further IL-1 's ability to enhance the antitumor activity of cytotoxic drugs, we initiated studies to examine the effect of IL-1 on cisplatin (cDDP)-mediated cytotoxicity using the RIF-1 tumor system. The antitumor activity of IL-1 and cDDP was quantitated through standard clonogenic tumor-cell survival assays, a tumor hemorrhagic necrosis assay and tumor-regrowth delay studies, with the interaction between IL-1 and cDDP being analyzed through median dose-effect. In vitro, IL-1 had no enhancing effect on the cDDP-mediated tumorcell kill. For examination of the in vivo efficacy of this regimen. RIF-1 tumor-bearing C3H/HeJ mice (14 days postimplantation) were treated concurrently with single i.p. injections of IL-1 and/or cDDP at various doses. The increased clonogenic tumor-cell kill obtained with IL-1 /cDDP was dose-dependent, with significant enhancement by IL-1 being observed (P<0.001), even at the lowest doses tested (2 mg/kg and 6 g/kg for cDDP and IL-1 , respectively), but it did not correlate with an increase in tumor hemorrhage. Using median dose-effect analysis, this interaction was determined to be strongly synergistic. When treated animals were monitored for long-term antitumor effects, combinations with IL-1 significantly increased the tumor-regrowth delay and decreased the fractional tumor volume (P<0.001). These results demonstrate that IL-1 synergistically enhances cDDP mediated in vivo antitumor activity and suggest that the combination of IL-1 and cDDP may have potential therapeutic application in the design of effective treatment modalities for cancer.Abbreviations IL-1 interleukin-1 - cDDP cis-diamminedichloroplatinum (cisplatin) - BRMs biological response modifiers - TNF tumor necrosis factor - IFN interferon - Fa traction affected - D_m or ED₅₀ drug concentration necessary to produce Fa=0.5 as compared with untreated controls - CI combination index; SF, surviving fraction - ANOVA oneway analysis of variance This work was supported in part by Public Health Service grant CA-48077 from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services, by the Mary Hillman Jennings Foundation, and by the Ramona DeSantis Cancer Research Fund     

Glycogen‐rich carcinomas of the breast display unique characteristics with respect to proliferation and the frequency of oligonucleosomal fragments

We determined the proliferation rate and apoptotic activity of glycogenrich carcinomas of the breast as opposed to nonclear cell tumors by means of MIB1 immunohistochemistry and in situ detection of oligonucleosomal fragments (TUNEL reaction). The retrospective biopsy series included six invasive clear cell carcinomas of the glycogenrich type as well as 15 randomly selected cases of invasive ductal carcinoma without evidence of glycogen storage. Three patients in the clear cell group and seven patients in the control cohort developed lymphnode metastasis. The MIB1 labeling index of glycogenrich carcinomas averaged 9.05%, while that of the controls was 30.03%. Apoptotic nuclei were present in a mean of 1.26% of glycogenrich carcinoma cells. The control tumors exhibited an average apoptotic frequency of 5.85%. Tumor size, hormone receptor status, and presence or absence of lymph node involvement were found not to correlate with either proliferation or apoptosis. We conclude that glycogenrich breast carcinomas are characterized by a peculiar low proliferationlow apoptosis cell kinetic profile. The aggressive clinical behavior of these neoplasms may possibly be accounted for by an ineffective apoptotic elimination of otherwise slowly proliferating tumor cells.     

Immune adjuvants for chemotherapy or radiotherapy in the 9L rat brain tumor model

Summary The therapeutic efficacy and toxicity of three biological response modifiers,Corynebacterium parvum (Cp), Chinese blister beetle extract (CBBE), recombinant human IL-1 (rhIL-1), used alone or in combination with chemotherapy or radiotherapy, were investigated in the intracerebral (ic) rat 9L brain tumor model. Used alone, Cp (2mg/rat, ip plus 70g/rat, ic), CBBE (5l of an ethanol extract, ic), or IL-1 (lg/rat, ic or 1g/rat × 3, q 3 d, ic), had no effect on animal survival compared to the untreated or saline treated controls. When combined with chemotherapy or radiotherapy, the three immunotherapeutic agents did not show any additive effects on survival compared to that observed with systemic BCNU (12mg/kg), local ic bleomycin (0.25 unit), or local radiotherapy (16 Gy). While ic IL-1 did not produce evident toxicity, there was fatal toxicity caused by ic Cp or CBBE treatment in a few animals. The combination of Cp and bleomycin produced severe neurotoxicity, resulting in the early death of animals. This study demonstrates a lack of efficacy of the nonspecific immune adjuvants IL-1, Cp or CBBE, used either alone or combined with cytotoxic chemotherapy or radiotherapy, in this rat brain tumor model.     

Response of multicellular tumor spheroids to liposomes containing TNF-α

Summary This publication describes a new model to investigate the influence of tumor necrosis factor- (TNF-) on a three-dimensional glial cell aggregate under defined, standardized, reproducible conditions using the glioma cell line A 172.The cells are initially grown as normal monolayer culture until they reach a cell density of up to 1×10⁶. Subsequently they are grown as spheroids by the liquid overlay technique. Spheroids grown in this way were divided into ten groups of more than 50 cell aggregates. Three groups were coincubated with free TNF- in increasing dosages (100 ng/ml, 200 ng/ml and 1000 ng/ml); three groups were incubated with empty liposomes (0.2 mg/ml, 0.4 mg/ml and 2 mg/ml); three groups received liposomes which had been loaded with TNF-, and one group, which received no treatment, served as control.The diameter of the spheroids ranged from 80 m to 350 m. There was no significant difference in growth between the 3 groups treated with free TNF-. Comparing spheroids treated with TNF- with those which had been coincubated with empty liposomes, there was a significant difference (p<0.001) in growth, which correlated with the amount of liposomes. Similarly, free TNF- had a significantly (P<0.001) stronger growth-inhibiting effect as compared to liposomes loaded with TNF-. Comparing the groups treated with liposomes only to those treated with liposomes loaded with TNF-, the latter exhibited a more marked (although not significantly) growth-inhibiting effect.The preliminary conclusion is that the major growth-inhibiting effect seems to be mediated by the liposomes. This phenomenon is in agreement with results obtained in monolayer cultures.     

Induction of matrix metalloproteinases MMP-1 and MMP-2 by co-culture of breast cancer cells and bone marrow fibroblasts

Two invasive breast cancer cell lines (MDA-MB-231 and BT-549) were found to be more adherent and have greater migratory capacity on bone marrow fibroblasts than three non-invasive cell lines (MCF-7, T47D and BT-483). Antibodies to the adhesion molecules CD44, E-cadherin, ICAM-1, and integrin chains 2, 3, 4, 5, 6, v, 1, 3 and 7 failed to inhibit breast cancer cell migration through bone marrow fibroblasts. Inhibitors of matrix metalloproteases, 1, 10-phenanthroline, Ro-9790, TIMP-1 and TIMP-2 were able to attenuate the migration of MDA-MB-231 cells through bone marrow fibroblast monolayers suggesting a role for these enzymes in the migration of breast cancer cells through bone marrow adherent layers. Co-culture of MDA-MB-231 cells and bone marrow fibroblasts resulted in augmentation of the levels of the matrix metalloproteases MMP-1 and MMP-2 in culture supernatants. Soluble factors produced by bone marrow fibroblasts were responsible for the increase in MMP-1 levels. However, maximal MMP-2 production was dependent on direct contract between the breast cancer cells and the bone marrow fibroblasts. Modulation of MMP production by cell–cell contact or soluble factors suggests a mechanism by which breast cancer cells can enhance their ability to invade the bone marrow microenvironment.     

Impact de l’accès à Internet dans la relation médecin/malade en cancérologie. Réflexions à partir d’un cas clinique.

Résumé: De plus en plus de patients atteints de cancer surfent sur Internet pour trouver des informations sur leur pathologie. Les caractéristques dInternet—facilité daccès, absence de médiation, encyclopédisme, profusion—bouleversent les modes daccès, de transmission et dutilisation du savoir médical. La relation médecin/patient en est bouleversée, plus spécialement dans le cas des maladies graves où le contenu émotif lié à la délivrance du diagnostic (et plus encore du pronostic) exacerbe les enjeux de la relation. À partir dun cas clinique particulièrement représentatif, cet article a pour objet de réfléchir à différentes problématiques:—quen est-il de linformation médicale aujourdhui?—lutilisation dInternet est-elle susceptible dentraver ladaptation psychique des patients confrontés au cancer?—quelles réflexions peut-on en tirer pour la pratique du cancérologue?     

Conjugation of interferon alpha to a humanized monoclonal antibody (HuBrE-3vl) enhances the selective localization and antitumor effects of interferon in breast cancer xenografts

Human mammary carcinoma xenografts (MCF-7) growing in nude mice were treated with natural interferon (n-IFN-) alone or conjugated to a humanized monoclonal antibody (MoAb) anti-breast mucin (HuBrE-3vl) or to irrelevant human IgG₁. The IFN and the conjugates were administered as 20 intra-lesional (i.l.) injections to 1 of 2 xenografts in each mouse, or i.p. The growth inhibitory effects of HuBrE-3vl/nIFN- were significantly greater than those of nIFN- used as a single agent or conjugated to HuIgG₁. These effects occurred locally in the tumors receiving i.l. injections and systemically, although to a slightly lesser extent, in the noninjected tumors of mice treated i.l. and in the xenografts of mice treated i.p. Biodistribution studies showed that the uptake of ¹²⁵I-HuBrE-3vl/nIFN- by the tumors 24 hours after i.l. or s.c. injection was greater than that of ¹²⁵I-HuIgG₁/nIFN-,¹²⁵ I-nIFN- alone, or by normal tissues, documenting a tumor targeting effect and favorable tumor:normal tissues (T:NT) ratios. The targeting effects and the resulting tumor growth inhibition were favored by the IFN-mediated up-regulation of the HuBrE-3vl reactive antigen, which was more prominent after 3 weeks of treatment with HuBrE-3vl/nIFN-. These results were superior to those we obtained previously with nIFN- conjugated to another MoAb of the same group (Mc5). These studies point out the potential usefulness of HuBrE-3vl/nIFN- for the local and systemic treatment of breast cancer lesions by providing a means of delivering high doses of IFN to the tumors while minimizing the amount of IFN binding to normal tissues.     

Down-regulation of transforming growth factor-β and interleukin-10 secretion from malignant glioma cells by cytokines and anticancer drugs

The effect of treatment with interleukin-1 (IL-1), interferon- (IFN-), vincristine, and etoposide was evaluated on the secretion of transforming growth factor- (TGF-) and IL-10 and the expression of major histocompatibility complex (MHC) class I, intercellular adhesion molecule-1 (ICAM-1), and CD80 molecules by malignant glioma cells. Five malignant glioma cell lines were treated with IL-1, IFN-, and/or anticancer agents (vincristine and etoposide). Combined treatment with IL-1 and IFN- caused greater inhibition of TGF- secretion compared to treatment with IFN-, and almost the same levels of inhibition as treatment with vincristine and etoposide. The greatest inhibition of TGF- secretion was achieved by treatment with all agents. Low levels of IL-10 secretion were determined in two out of five malignant glioma cell lines. This IL-10 secretion was inhibited by treatment with IL-1, IFN-, vincristine, and/or etoposide. Treatment with both cytokines and anticancer agents increased the expression of MHC class I and ICAM-1 in all tumor cell lines. The mean increase of expression of MHC class I was 50% and that of ICAM-1 was 12-fold. No tumor cell lines expressed CD80 molecules on the cell surface, and no treatment caused CD80 expression. These results suggest that TGF- and IL-10 secretion by malignant glioma cells can be suppressed by treatment with a combination of IL-1, IFN-, vincristine, and etoposide, and the treatment up-regulates MHC class I and ICAM-1 expression on tumor cells. These results have implications for immunotherapy and chemotherapy in patients with malignant tumors.     

In vivo effects in mice produced by a 3′-branched homologue of α-2′-deoxythioguanosine

Summary Studies with a 3-branched chain homolog (-3-BCTGdR) of 2-deoxythioguanosine (-TGdR) showed that it did not prolong the survival of mice bearing the Mecca lymphosarcoma. Host toxicity was quite profound and resembled that seen with 6-thioguanine (6-TG). Evidence was obtained that this nucleoside derivative was not appreciably converted to 6-TG in the mouse. Mice treated with toxic doses of 6-TG or -3-BCTGdR were found to have very similar pathological changes. The granulocytes were eliminated from the peripheral blood, bone marrow was acellular, and some more limited damage was seen in the intestinal crypts. Experiments with radiosulfur-labeled drugs demonstrated that -3-BCTGdR was incorporated into the DNA of mouse bone marrow, predominantly in the chain-terminating position, with the result that shorter chains of DNA accumulated. The new homolog, unlike -TGdR, was phosphorylated in bone marrow as well as in tumor, and incorporated well into the DNA both of bone marrow and of the neoplastic cells. In devising other homologs attention must be given to the specificity of the kinases, i.e., to whether phosphorylation is superior in tumor cells or in the growing normal cells.Abbreviations used are 6-TG 6-thioguanine - ,-TGdR ,-2-deoxythioguanosine - -3-BCTGdR 6-thioguanine--2,3-dideoxy-3-(hydroxymethyl)-d-erythro-pentofuranose - ³H-TdR Tritium-labeled (methyl) thymidine     

The use of natural interferon alpha conjugated to a monoclonal antibody anti mammary epithelial mucin (Mc5) for the treatment of human breast cancer xenografts

Summary An immunoconjugate composed of natural interferon (nIFN) bound in a noncleavable fashion to a monoclonal antibody (MoAb) recognizing a breast epithelial membrane mucin (Mc5) was used to treat xenografts of a human mammary carcinoma cell line (MCF-7) growing in nude mice. The immunoconjugate (nIFN/Mc5) was administered as 20 intralesional (i.l.) injections to 1 of 2 xenografts in each animal. It was found that nIFN/Mc5 produced a significant enhancement of the growth inhibitory actions of nIFN on the injected tumors. Further enhancement was obtained when nIFN or nIFN together with Mc5 (at a dose 10 times larger than that present in nIFN/Mc5) were added to the immunoconjugate. Biodistribution experiments showed that the uptake of¹²⁵I-nIFN/Mc5 by the tumors was greater and its elimination slower than for¹²⁵I-nIFN alone or conjugated to irrelevant mouse IgG₁. In addition, the immunoconjugate up-regulated the antigenic expression of a breast epithelial membrane mucin by the carcinoma cells, an up-regulation which was not significantly different from that produced by nIFN alone. The contralateral noninjected tumors exposed to systemic levels of the immunoconjugate showed an enhancement of antitumor effects, but to a lesser extent than the injected tumors. These findings suggest that the enhancement of the growth inhibitory action of the immunoconjugate was related to the specific binding of Mc5 which targeted the IFN to the carcinoma cells and impeded its elimination. It is likely that the targeting was favored by the IFN-mediated up-regulation of antigenic expression by the carcinoma cells, thereby producing a cascade of interrelated effects. The results of this study point out the feasibility and potential usefulness of IFN treatment by means of immunoconjugates as well as the worth of pursuing and improving this form of therapy.