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Biomedical subjects

M Grandi

Publications and source records attributed to M Grandi.

At least 37 records · Page 2Linked to original sources

FCE 27266, a sulfonic distamycin derivative, inhibits experimental and spontaneous lung and liver metastasis.

FCE 27266, 2,2,'-(carbonyl-bis(imino-N-methyl-4,2-pyrrole carbonyl-imino¿N-methyl-4,2-pyrrole¿carbonylimino])-bis- (1,5-naphthalene) disulfonic acid, is a noncytotoxic compound able to complex bFGF, PDGF beta, IL-8, VEGF and IL-1 beta and to inhibit the binding to their receptors. A single intravenous treatment 48 h prior to intravenous injection with tumor cells was associated with 60% inhibition of lung metastasis from B16F10 murine melanoma and 82% inhibition of liver metastasis from M5076 murine reticulosarcoma. Marginal inhibition was observed in the latter model, administering the drug 24 h after tumor cell injection. Efficacy was maintained in athymic mice, with 95 and 100% inhibition of lung metastasis from B16F10 melanoma and A375 human melanoma. The antimetastatic activity was confirmed in two models of spontaneous metastasis: in Lewis lung carcinoma implanted intramuscularly, daily intraperitoneal treatment from day 1 to 17 was associated with 77% inhibition of lung metastasis; on M5076 reticulosarcoma implanted intramuscularly, daily intraperitoneal treatment from day 1 to 14 prior to amputation of the tumor was associated with significant inhibition of liver metastasis (79%); conversely, daily intraperitoneal treatment from day 15 to 28 starting 1 day after amputation was marginally effective. The administered doses did not inhibit the growth of the primary tumor in both models. It is concluded that FCE 27266 is a novel, promising molecule, with significant efficacy on lung and liver metastases of murine and human origin; its mode of action is still under study and is probably exerted through inhibition of growth factors and cytokines influencing the different steps of angiogenesis and metastasis.

3T3 Cells↗

New sulfonated distamycin A derivatives with bFGF complexing activity.

Tumor-induced neoangiogenesis is an essential event for solid tumor growth. Therefore, a compound able to block angiogenesis-promoting factors could have antitumor activity. The polysulfonated naphthylurea suramin is hypothesized to have this mode of action. A series of sulfonated distamycin A derivatives have been synthesized with the objective of identifying novel compounds able to complex basic fibroblastic growth factor (bFGF) and other factors involved in tumour angiogenesis, and consequently to block the angiogenic process. These new compounds have been characterized for their ability to inhibit bFGF binding, in vivo bFGF-induced angiogenesis and neovascularization of the chorioallantoic membrane, in comparison with suramin. The two most active compounds, FCE 26644 [7,7'-(carbonyl-bis(imino-N-methyl-4,2-pyrrolecarbonyl-imino(N-met hyl-4,2- pyrrole)carbonylimino))-bis(1,3-naphthalenedisulfonic acid)] and FCE 27164 [7,7'-(carbonyl-bis(imino-N-methyl-4,2-pyrrolecarbonyl-imino(N-met hyl-4,2- pyrrole) carbonylimino)-bis (1,3,5-naphthalenetrisulfonic acid)] have been selected for extended evaluation. Both compounds are active in inhibiting platelet-derived growth factor beta (PDGF beta) and interleukin-1 beta binding. Two different assays have been performed to study their mode of action: the sequential binding assay on bFGF and PDGF receptors and the bFGF-induced tyrosine phosphorylation assay. The results of the two assays are in agreement and indicate that no activity is observed if FCE 26644, FCE 27164 and suramin are administered as pretreatment, when a direct interaction of the compounds with bFGF and PDGF receptors is required. Conversely, inhibitory activity is observed when the compounds are allowed to form complexes with the growth factors themselves.

3T3 Cells↗

Growth-inhibitory properties of novel anthracyclines in human leukemic cell lines expressing either Pgp-MDR or at-MDR.

The objective of the experiments reported in this paper was the identification of promising anthracycline analogs on the basis of lack of cross-resistance against tumor cells presenting either P-glycoprotein multidrug resistance (Pgp-MDR) or the altered topoisomerase multidrug resistant (at-MDR) phenotype. Differently modified anthracycline analogs known to be active against MDR cells were assayed in vitro against CEM human leukemic cells, and the sublines CEM/VLB100 and CEM/VM-1 exhibiting respectively the Pgp-MDR and the at-MDR phenotype. Two classes of molecules, in which the -NH2 group in C-3' position is substituted with a morpholino, methoxymorpholino (morpholinyl-anthracycline), or an alkylating moiety, present equivalent efficacy in the drug-sensitive and the two drug-resistant sublines. These results indicate that such molecules may exert their cytotoxic effect through a mode of action different from that of "classical" anthracyclines and is not mediated through topoisomerase II inhibition. Both molecules represent novel concepts in the field of new anthracyclines derivatives.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

L1210 cells selected for resistance to methoxymorpholinyl doxorubicin appear specifically resistant to this class of morpholinyl derivatives.

We investigated the mechanism of resistance in murine L1210 leukaemia cells selected after treatment with FCE 23762 methoxymorpholinyl doxorubicin: (MMRDX), a methoxymorpholinyl derivative of doxorubicin active in vitro and in vivo on multidrug-resistant (mdr) cells, currently undergoing phase I clinical trials. The resistant subline obtained after repeated in vitro treatments, L1210/MMRDX, is resistant in vitro and in vivo to all tested methoxymorpholinyl derivatives and to cyanomorpholinyl doxorubicin, but shows resistance to morpholinyl derivatives only in vivo or following their activation with rat S9-liver fractions in vitro. L1210/MMRDX cells are sensitive to classic mdr- and altered topoisomerase (AT)-mdr-associated drugs. These cells do not appear to overexpress the mdr1 gene, nor do they exhibit impaired intracellular drug accumulation and efflux or altered levels of glutathione and glutathione S-transferase. The extent of DNA single-strand break formation and, after microsomal activation, of DNA interstrand cross-links after treatment with MMRDX was similar in the parent and the resistant subline. The mechanism of resistance in L1210/MMRDX cells remains to be identified but may prove a novel one, highly specific for this class of mdr-active anthracyclines.

Animals↗

Lumbar hernia as congenital aplasia of lumbo-dorsal muscle.

A newborn with congenital aplasia of the dorso-lumbar muscles is described. The lesion seemed to be a congenital lumbar hernia and is a very uncommon feature. The child underwent surgery and although it was a very large bilateral defect, it was repaired without using prosthetic patch. The surgical technique and the results are discussed. The function of the region was conserved as demonstrated at the check-up of the child at 6 and 12 months of age.

Hernia↗

Reversal of multidrug resistance by new dihydropyridines with low calcium antagonist activity.

The clinical use of Ca++ antagonist agents as modulators of multidrug resistance is limited by their strong vasodilator activity. This study reports data obtained by testing a series of new 1,4 dihydropyridine derivatives (DHPs) for their in vitro resistance modulating activity and their Ca++ antagonist effect. All the tested DHPs are active to increase doxorubicin activity with dose modifying factor values ranging between 2 and 47 on P388/DX cells and 12 and 36 on LoVo/DX cells. Their resistance modulating action is exerted through an increase of DX intracellular level. The Ca++ antagonist activity of DHPs, evaluated as capacity to inhibit the KCl-induced contractions in isolated Guinea pig ileum strips, is not related to their resistance modulating activity. This finding makes it possible to select, for further in vivo evaluations, compounds IX, X and XI, which have strong ability to overcome multidrug resistance and low Ca++ antagonist effect.

Animals↗

Influence of structural modifications at the 3' and 4' positions of doxorubicin on the drug ability to trap topoisomerase II and to overcome multidrug resistance.

To better define the role of the amino sugar in the pharmacological and biochemical properties of anthracyclines related to doxorubicin and daunorubicin, we have investigated the effects of various substituents at the 3'- and 4'-positions of the drug on cytotoxic activity and ability to stimulate DNA cleavage mediated by DNA topoisomerase II. The study shows that the nature of the substituent at the 3'-position but not the 4'-position is critical for drug ability to form cleavable complexes. The amino group at the 3'-position is not essential for cytotoxic and topoisomerase II-targeting activities, because it can be replaced by a hydroxyl group without reduction of activity. However, the presence of bulky substituents at this position (i.e., morpholinyl derivatives) totally inhibited the effects on the enzyme, thus supporting previous observations indicating that the cytotoxic potencies of these particular derivatives are not related to topoisomerase II inhibition. This conclusion is also supported by the observation that 3'-morpholinyl and 3'-methoxymorpholinyl derivatives are able to overcome atypical (i.e., topoisomerase II-mediated) multidrug resistance. Because a bulky substituent at the 4'-position did not reduce the ability to stimulate DNA cleavage, these results support a critical role of the 3'-position in the drug interaction with topoisomerase II in the ternary complex. An analysis of patterns of cross-resistance to the studied derivatives in resistant human tumor cell lines expressing different resistance mechanisms indicated that chemical modifications at the 3'-position of the sugar may have a relevant influence on the ability of the drugs to overcome specific mechanisms of resistance.

Carcinoma, Non-Small-Cell Lung↗

Establishment of L1210 leukemia cells resistant to the distamycin-A derivative (FCE 24517): characterization and cross-resistance studies.

N-deformyl-N-[4-N,N-bis(2-chloroethylamino)benzoyl] distamycin-A (FCE 24517) is a new cytotoxic anti-tumor agent in phase-1 clinical trials. We have isolated stable FCE-24517-resistant cell sublines from murine leukemia L1210 cells by in vitro exposure to the drug. FCE 24517 selects a mixed population of resistant cells: the L1210/24517(1) cell line in vitro was in fact resistant to the selecting agent (RI 48.3), as well as to L-PAM (RI 5.4) and DX (RI 8.6) and over-expressed the mdr-I gene. When L1210/24517(1) cells were implanted in vivo and evaluated for sensitivity to the same agents, resistance was observed only to FCE 24517 and partially to L-PAM, whereas DX had the same anti-tumor efficacy as on the sensitive line. The clone derived from the above subline (L1210/24517(2)) was resistant to FCE 24517, distamycin-A and other cytotoxic compounds bearing the distamycin-A skeleton, and fully sensitive to DX and other anti-tumor compounds involved in the multi-drug resistance mechanisms, with a complete disappearance of the mdr phenotype. L1210/24517(2) cell line is partially cross-resistant to L-PAM, this resistance being accounted for by higher GSH intracellular levels, which however do not influence the resistance to FCE 24517. In fact, BSO treatment was capable of significantly modifying only the cytotoxicity of L-PAM. Our data suggest that L1210/24517(2) cells present a mechanism of resistance specific for FCE 24517 and related molecules.

Animals↗

Idarubicin is active on MDR cells: evaluation of DNA synthesis inhibition on P388 cell lines.

Multidrug resistance is frequently found in patients affected by hematological malignancies and has been related to a poor prognosis of acute leukemia. In the present paper we report results concerning the activity of idarubicin, an anthracycline derivative, on the leukemic P388 and P388 doxorubicin-resistant cell lines. The results clearly show that idarubicin inhibits DNA synthesis in the resistant cell line more actively than doxorubicin.

Animals↗

3'-Deamino-3'-(2-methoxy-4-morpholinyl)-doxorubicin (FCE 23762): a new anthracycline derivative with enhanced cytotoxicity and reduced cardiotoxicity.

The purpose of this study was to examine the cytotoxicity and cardiotoxicity of the new doxorubicin derivative, 3'-deamino-3'-(2-methoxy-4-morpholinyl)-doxorubicin (FEC 23762). The concentration of FCE 23762 that resulted in a 50% reduction in colony formation of DU 145, COLO 320DM, A549 and A2780 human cancer cell lines ranged from 1.1 and 3.2 nmol/l and was 3-9 times as low as doxorubicin. In the isolated perfused rat hearts, doxorubicin 10(-5) mol/l induced a significant prolongation of S alpha T segment and Q-Fmax interval, and reduction in dF/dtmax and coronary flow while only FCE 23762 10(-5) mol/l induced a widening of QRS complex. Anaesthetised rats given a single intravenous (i.v.) dose of doxorubicin 10 mg/kg showed significant changes in both ECG (S alpha T segment and QRS complex enlargement) and haemodynamic parameters (increase in mean arterial blood pressure and reduction in systemic arterial dP/dtmax), while animals given FCE 23762 (0.1 and 0.3 mg/kg) had a significant increase in QRS complex duration after the highest dose. In the chronic cardiotoxicity study animals receiving FCE 23762 (0.03 mg/kg i.v. once a week for 3 weeks) did not show any significant alteration of ECG and minor changes of cardiac histological picture; by contrast doxorubicin (3 mg/kg i.v. once a week for 3 weeks) induced a severe cardiomyopathy, characterised by progressive widening of S alpha T segment, increase in T wave and histological damage consisting of vacuolations and loss of myofibrils. These results indicate that FCE 23762 is more active in vitro than doxorubicin and markedly less cardiotoxic in vivo at the doses used in the present study.

Animals↗

Characterisation of a LoVo subline resistant to a benzoyl mustard derivative of distamycin A (FCE 24517).

Human colon adenocarcinoma cells (LoVo) resistant to the new antitumor agent FCE 24517 [benzoyl-mustard derivative of distamycin A] (LoVo/24517) are resistant to the selecting agent and related molecules as well as to vinblastine, with marginal or no resistance to other antitumour drugs. Treatment with verapamil, tamoxifen, nicergoline or cyclosporin A only partially restores the activity of FCE 24517 against LoVo/24517 cells. Such results suggest that resistance mechanisms possible specific for this class of compounds are operating.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Inhibition of lung and liver tumor colonies in mice pretreated with suramin.

The effect of suramin on B16F10 melanoma lung colonies and M5076 reticulosarcoma liver metastasis formation was evaluated in C57B1/6 female mice. Single i.v. doses of 200 mg/kg suramin given 48 and 24 h prior to tumor cell injection significantly inhibited metastasis formation in both models, whereas the same treatment administered 24 h after cell injection was ineffective. A dose-response experiment in the B16F10 melanoma model showed that inhibition of lung colony formation was still significant with 50 mg/kg pretreatment, whereas a borderline effect was observed at 10 mg/kg. At the effective doses, the plasma and organ concentrations of suramin were far below those needed to exert significant in vitro cytotoxic or cytostatic effects on B16F10 and M5076 cells. Thus, in addition to the antineoplastic effect of suramin our results indicate a potential antimetastatic role for this compound.

Animals↗

In vitro activity of novel sulphonic derivatives of distamycin A.

The successful growth of tumors is dependent on the process of vascularization elicited by the tumor itself. As confirmed by many authors, there is a correlation between the presence of factors that stimulate tumor growth and angiogenesis. One of the approaches we have explored to control angiogenesis has been to synthesize compounds able to complex growth factors. A number of sulphonated derivatives of distamycin A were found active in inhibiting the binding of bFGF and PDGF beta on Swiss 3T3 cells with ID50 values ranging between 142-587 microM for bFGF and 28-79 microM for PDGF beta. The effect of these new derivatives in inhibiting angiogenesis was initially explored in the chorioallantoic membrane assay. It was observed that the selected compounds were active in this model system at the concentration of 350 nm/pellet. These new molecules present low or no cytotoxic activity on M5076 murine reticulosarcoma cells, the ID50 values being higher than 60 microM after 72 h continuous exposure in vitro.

3T3 Cells↗

In vivo activity of novel sulphonic derivatives of distamycin A.

Solid tumor growth can be modulated through inhibition of vascularization elicited by angiogenic factors. With the objective to complex these factors, new derivatives of distamycin A were synthesized and evaluated in vitro [1] and in vivo for their ability, after i.v. administration, to inhibit bFGF-induced vascularization and the growth of M5076 murine reticulosarcoma implanted i.m. The tested compounds were able to block angiogenesis with inhibition values ranging between 70-100%. Moreover, they were found to be capable of inducing tumor inhibition with values ranging between 40% and 95% at non-toxic doses.

Animals↗

In vivo anti-tumour activity of FCE 23762, a methoxymorpholinyl derivative of doxorubicin active on doxorubicin-resistant tumour cells.

FCE 23762 is a new doxorubicin derivative obtained by appending a methoxymorpholinyl group at position 3' of the sugar moiety. The compound is greater than 80 times more potent than doxorubicin, it is highly lipophilic, and presents equivalent anti-tumour activity when administered by i.p., i.v. or oral route. The pattern of anti-tumour activity of FCE 23762 differs from that of doxorubicin in maintaining anti-tumour activity against two P388 murine leukaemia sublines resistant to doxorubicin and, although at borderline levels of efficacy, against LoVo human colon adenocarcinoma resistant to doxorubicin. FCE 23762 exhibits remarkable efficacy against MX-1 human mammary carcinoma, with most treated mice being cured both after i.v. and oral treatment. Anti-tumour activity was also observed against L1210 murine leukaemia and two sublines resistant to cis-platinum and melphalan, M5076 murine reticulosarcoma, MTV murine mammary carcinoma and N592 human small cell lung cancer.

Animals↗

Suramin prevents neovascularisation and tumour growth through blocking of basic fibroblast growth factor activity.

Inhibition of angiogenesis through blocking of growth factors involved in this process could be a novel therapeutic approach in several important pathologies, neoplasia among them. Suramin has recently been described to possess antineoplastic activity in animals and humans, and it has been proposed that an important role in this activity is played by antagonism of growth factors and especially bFGF. To investigate this hypothesis in vivo, we used gelatin sponges loaded with bFGF and implanted subcutaneously in mice. Suramin showed an inhibitory activity on bFGF-induced angiogenesis, whereas it was inactive in the case of heparin-complexed bFGF. Suramin was also studied in an in vivo model of tumour-induced angiogenesis using the murine M5076 reticulosarcoma, a tumour producing significant levels of bFGF. Suramin was able to reduce tumour growth and tumour induced angiogenesis, and exogenous administration of bFGF countered suramin effects.

Animals↗

Reduced cardiotoxicity of doxorubicin given in the form of N-(2-hydroxypropyl)methacrylamide conjugates: and experimental study in the rat.

A rat model was used to evaluate the general acute toxicity and the late cardiotoxicity of 4 mg/kg doxorubicin (DOX) given either as free drug or in the form of three N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates. In these HPMA copolymers, DOX was covalently bound via peptide linkages that were either non-biodegradable (Gly-Gly) or degradable by lysosomal proteinases (Gly-Phe-Leu-Gly). In addition, one biodegradable conjugate containing galactosamine was used; this residue was targeted to the liver. Over the first 3 weeks after the i.v. administration of free and polymer-bound DOX, all animals showed a transient reduction in body weight. However, the maximal reduction in body weight seen in animals that received polymer-bound DOX (4 mg/kg) was significantly lower than that observed in those that received free DOX (4 mg/kg) or a mixture of the unmodified parent HPMA copolymer and free DOX (4 mg/kg; P less than 0.01). Throughout the study (20 weeks), deaths related to cardiotoxicity were observed only in animals that received either free DOX or the mixture of HPMA copolymer and free DOX; in these cases, histological investigations revealed marked changes in the heart that were consistent with DOX-induced cardiotoxicity. Sequential measurements of cardiac output in surviving animals that received either free DOX or the mixture of HPMA copolymer and free DOX showed a reduction of approximately 30% in function beginning at the 4th week after drug administration. The heart rate in these animals was approximately 12% lower than that measured in age-matched control rats (P less than 0.05). Animals that were given the HPMA copolymer conjugates containing DOX exhibited no significant change in cardiac output throughout the study (P less than 0.05). In addition, no significant histological change was observed in the heart of animals that received DOX in the form of HPMA copolymer conjugates and were killed at the end of the study. However, these animals had shown a significant increase in heart rate beginning at 8 weeks after drug administration (P less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Acrylamides↗