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Biomedical subjects

M D'Incalci

Publications and source records attributed to M D'Incalci.

At least 73 records · Page 4Linked to original sources
PubMed1998

Inactivation of p53 in a human ovarian cancer cell line increases the sensitivity to paclitaxel by inducing G2/M arrest and apoptosis.

Paclitaxel-induced cytotoxicity, cell cycle perturbation, and apoptosis were determined in a human ovarian cancer cell line expressing wt p53 (A2780) and in a subclone (A2780/E6) obtained upon transfection with the product of the E6 gene of the human papilloma virus HPV16. The inactivation of wt p53 in A2780/E6 was verified by measuring the inability of the clone to induce p53 and p21 expression after paclitaxel treatment. The p53-negative clone (A2780/E6) was approximately 50-fold more sensitive to paclitaxel than wt p53-expressing A2780 cells. This increased sensitivity was related to the ability of paclitaxel to induce a strong arrest of cells in the G2/M phase of the cell cycle in A2780/E6 but not in A2780 cells. This different cell cycle arrest was accompanied by increased frequency of paclitaxel-induced p53-independent apoptosis. Initial studies on proteases activation tend to exclude a direct role of ICE and CPP32 in the induction of apoptosis in these cells and show a paclitaxel-dependent increase in FLICE levels, whose biological relevance is however at present not defined.

Antineoplastic Agents, Phytogenic↗
PubMed1998

High-performance liquid chromatography tandem mass spectrometry procedure with automated solid phase extraction sample preparation for the quantitative determination of paclitaxel (Taxol) in human plasma.

A sensitive, specific, accurate and reproducible analytical method was developed and validated for the quantitation of the anticancer agent paclitaxel in human plasma. This procedure is based on high performance liquid chromatography/ion spray-tandem mass spectrometry. This methodology is highly specific because a MS/MS technique (multiple reactant-ion monitoring, MRM) was used for both paclitaxel and its internal standard. The use of a fully automated solid phase extraction procedure, using a CN Sep-pak cartridge, to improve the detection limit and quantification limit of paclitaxel in human plasma samples, was evaluated. The method involves the addition of methyl-paclitaxel as internal standard (i.s.). The retention times of paclitaxel and the I.S. were 2.8 and 4.0 min., respectively. The assay was linear over the range 5 to 500 ng/mL, with a quantification limit of 5 ng/mL having a coefficient of variation (c.v.) < 10%. Standard calibration curves, performed on three different days, had correlation coefficients always greater than 0.998. The intra and inter-day precision were within 12%, and accuracy was included in the range 102-110%. Paclitaxel recovery assessed at 15,250 and 500 ng/mL, was determined to be greater than 85%. The assay is applicable to clinical pharmacokinetic studies.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Hematotoxicity on human bone marrow- and umbilical cord blood-derived progenitor cells and in vitro therapeutic index of methoxymorpholinyldoxorubicin and its metabolites.

PURPOSE: MMDX [3'-deamino-3'-[2(S)-methoxy-4-morpholinyl] doxorubicin], an anthracycline derivative active in vitro and in vivo against multidrug-resistant tumors, is currently under investigation in phase I clinical trials. In vivo it is metabolically activated, resulting in more cytotoxic compounds. We determined in vitro the toxic concentration of a 1-h period of exposure to doxorubicin (DX), MMDX, and bioactivated MMDX on hematopoietic progenitors and tumor cell lines. METHODS: DX and MMDX were tested on both bone marrow- (BM) and cord blood (hCB)-derived clonogenic cells, whereas the metabolites were tested on hCB only. All substances were tested on seven tumor cell lines. RESULTS: BM cells proved to be twice as sensitive as hCB cells to cytotoxics, and MMDX was twice as toxic as DX against hCB cells; MMDX activated with normal rat-liver microsomes and with dexamethasone-induced rat microsomes were, respectively, 70 and 230 times more toxic than MMDX. A comparison of the cytotoxic concentrations on hematopoietic progenitors and tumor cells, revealed that DX and MMDX had 5-fold stronger activity on tumor cell lines than on granulocyte/macrophage colony-forming cells (GM-CFCs), whereas bioactivated MMDX showed comparable cytotoxicity against tumor cells and hematopoietic progenitors. CONCLUSIONS: MMDX metabolites are very potent but display a lower degree of tumor selectivity than MMDX. Strategies to reduce MMDX metabolization should be developed to optimize the therapeutic index of this new anthracycline.

Antibiotics, Antineoplastic↗
PubMed1998

Pharmacokinetics of anticancer agents in patients with impaired liver function.

This report reviews published information on the clinical pharmacokinetics of antitumour agents in patients with liver dysfunction, associated with primary liver disease or liver metastases. Information was available for anthracyclines and their related compounds, antimetabolites, cyclophosphamide, vinca alkaloids, taxanes and epipodophyllotoxins. Changes in the pharmacokinetic profile or metabolism in patients with mild or severe hepatobiliary dysfunction are described and the relationships between serum levels, parameters employed for measuring hepatic function and toxic or therapeutic effects are examined. Current knowledge of the pharmacokinetics of antineoplastic agents in liver disease is far from complete, mostly obtained in small numbers of non-homogeneous patients often presenting only moderate liver dysfunction, and empirical guidelines for dose assessment are still largely applied in clinical practice. Because of the complex pathophysiological mechanisms of liver insufficiency in cancer patients, there is still doubt whether endogenous markers are useful. Although caution in treating cancer patients with liver insufficiency is compulsory, for most compounds there seems no need to recommend dose reductions for moderate impairment. However, for the tubulin acting agents, vincristine, vinblastine and possibly for paclitaxel and docetaxel, there is strong evidence that dose adjustment is mandatory in order to avoid excessive neutropenia and neurotoxicity.

Anthracyclines↗
PubMed1998

Molecular characterisation of a panel of human ovarian carcinoma xenografts.

In a panel of 16 human ovarian tumours transplanted in nude mice, the expression of genes involved in cell cycle regulation and in response to drug treatment were characterised. In the 16 tumours analysed we could not detect overexpression of Erb-B2 oncogene while expression of MDR1 mRNA was not detected in 11/15 samples and was low in 4/15 tumours. Only three tumours had mutations in the p53 gene exons 5-8 and one of these mutations did not result in any amino acid alteration. The levels of mRNA for cyclins A, D1 and E were heterogeneous with some tumours expressing high levels and others not expressing them at all. The same was found for the cyclin dependent kinases (CDK) CDK2 and CDK4 and for CDK inhibitors p21/WAF1, p27/KIP1 and p16/CDKN2. Two genes belonging to the nucleotide excision repair, ERCC1 and ERCC3 were detectable in all the samples examined, as were the genes MGMT and MAG, also involved in DNA repair. The data indicate a heterogeneity in the expression of genes considered to be involved in the cellular responses to cytotoxic drug treatment and indicate the possibility of using these tumour models to test specifically molecules with a defined mechanism of action.

Animals↗
PubMed1998

Expression of genes involved in nucleotide excision repair and sensitivity to cisplatin and melphalan in human cancer cell lines.

DNA repair has been proposed to be an important determinant of cancer cell sensitivity to alkylating agents and cisplatin (DDP). Nucleotide excision repair (NER), which represents one of the most important cellular DNA repair processes able to remove a broad spectrum of DNA lesions, is involved in the recognition and repair of the crosslinks caused by DDP and melphalan (L-PAM). In this study, the mRNA levels of the different genes involved in NER (ERCC1, XPA, XPB, XPC, XPD, XPF) were examined in a panel of eight different human cancer cell lines, together with the overall DNA repair capacity using a host cell reactivation assay of a damaged plasmid. A statistically significant correlation was observed between the relative expression of XPA/XPC (P < 0.05) and ERCC1/XPC (P < 0.05) mRNAs. No correlation was found between the DDP and L-PAM IC50S and the relative mRNA expression of the tested NER genes. When the overall cellular DNA repair capacity was studied, carcinomas seemed to have a higher repair activity than leukaemias; but this repair DNA activity correlated neither with the mRNA expression of the different NER genes nor with DDP and L-PAM IC50S. These data seem to suggest that even if the NER pathway is an important determinant for the cytotoxicity of alkylating agents, as demonstrated by the extremely high sensitivity to alkylating agents in cells lacking this repair system, other factors have to play a role in regulating the cellular sensitivity/resistance to these antitumour drugs.

Antineoplastic Agents↗
PubMed1998

The antitumour activity of alkylating agents is not correlated with the levels of glutathione, glutathione transferase and O6-alkylguanine-DNA-alkyltransferase of human tumour xenografts. EORTC SPG and PAMM Groups.

Twenty-three human xenografts, including five colon, five gastric, nine lung (three small cell lung cancer) and four breast carcinomas, were investigated for their sensitivity to nitrosoureas, dacarbazine (DTIC), cyclophosphamide (CTX) and cisplatin (DDP). In 12 cases, at least one of the drugs produced complete or partial remission, in 2, a minor regression was observed and in the other 9, treatment was ineffective. The level of sensitivity to each drug, using a score from 1 to 5, was correlated to three biochemical parameters reported to be involved in resistance to alkylating agents: glutathione (GSH), glutathione transferase (GST) and O6-alkylguanine-DNA-alkyltransferase (AGT). A wide variability was found in these parameters in the xenografts investigated. No correlation was found between any of the three parameters and sensitivity to the drugs used or between sensitivity to one drug and to any of the other drugs tested. These results illustrate the complexity of the question of resistance to alkylating agents and indicate that, at least in xenografts, the biochemical parameters examined are not predictive of response to alkylating agents.

Alkyl and Aryl Transferases↗
PubMed1998

DNA-topoisomerase I activity and content in epithelial ovarian cancer.

BACKGROUND: The levels and activity of topoisomerase I were determined in 35 biopsies from patients with ovarian cancer. PATIENTS AND METHODS: The activity was defined by the ability to relax supercoiled DNA plasmid, and levels were determined by Western blotting and immunohistochemistry. RESULTS: We detected topoisomerase I activity in all samples, although at different levels. Enzymatic activity was the same in fresh and frozen tissues. Western blotting analysis detected topoisomerase I in 29 of 35 tumor samples but in the remaining six the levels were below the detection limit. We analyzed the distribution of topoisomerase I in tumor cells and normal infiltrating cells by immunohistochemistry. The enzyme was mainly associated with tumor cells although there were four samples in which tumor cells were negative but in which normal cells, mainly lymphocytes, yielded a positive result. CONCLUSIONS: The results indicate that topoisomerase I enzymatic activity is detectable in human ovarian tumors, varying among patients. No correlations were found between the levels of the enzyme and its activity. Because of the high heterogeneity observed, enzymatic activity assays should be combined with immunohistochemical evaluation of Topo I in the tumor and normal cells present in the tissue.

Adult↗
PubMed1998

Phase I clinical and pharmacokinetic study of the oral platinum analogue JM216 given daily for 14 days.

BACKGROUND: The oral bis (acetate) ammine dichloro cyclohexylamine platinum (IV) analogue (BMS-182751) was brought into clinical development because it was shown to be cytotoxic against some human tumour cell lines and to have an antitumor activity in murine tumours at least comparable to that of parenteral cisplatin and carboplatin. In early clinical studies in which the optimal schedule of treatment was daily for five consecutive days, dose-dependent nausea and vomiting occurred in about two-thirds of patients. PATIENTS AND METHODS: To evaluate if the use of lower daily doses for longer periods of time could result in a better tolerability, JM216 was given once daily for 14 consecutive days every four to five weeks to adult patients with solid tumors. Oral antiemetics were given prophylactically only at the highest doses. The pharmacokinetics of total and ultrafiltrable platinum were studied on days 1 and 14 of the first cycle by Inductively Coupled-Mass-Spectrometry (ICP-MS). RESULTS: Forty-six patients were treated at doses ranging from 10 mg/m2/d to 50 mg/m2/d and 39 were evaluable for hematologic toxicity over 74 cycles. MTDs were reached at 45 mg/m2/d and 50 mg/m2/d x 14 repeated every five weeks in patients with extensive, or limited/no prior treatment, respectively. The dose-limiting toxicity was neutropenia which was delayed and variable among patients. Other non-hematological toxicities were severe vomiting (22% of cycles), diarrhea (28% of cycles) and drug-associated fever (32% of patients), controlled with paracetamol. Subjective improvement with disappearance of tumour-related pain was observed in one patient with chemotherapy-resistant metastatic prostate cancer and in one previously untreated patient with malignant mesothelioma. Cmax and AUC values of both total and ultrafiltrable platinum on days 1 and 14 were highly variable among patients. Only Cmax on day 1 was linearly related to the dose. Total and ultrafiltrable platinum were still detectable two weeks after the last dose. No relationship could be established between AUC values and toxicities. CONCLUSIONS: Daily doses of JM216 of 40 mg/m2 and 45 mg/m2 for 14 consecutive days every five weeks with oral antiemetic prophylaxis are selected for phase II evaluation of single agent in patients with extensive or limited/no prior treatment, respectively. The administration of JM216 on a day x 14 schedule produced nausea and vomiting comparable to that observed with the day x 5 regimen but of longer duration. The variability of pharmacokinetics and pharmacodynamics, even though limited at the doses proposed for phase II evaluation of JM216 as single agent, recommend a careful monitoring of the patients.

Administration, Oral↗
PubMed1998

IFN-beta partially counteracts inhibition of natural killer activity induced by some antitumor agents.

We investigated whether recombinant human (rHu-IFN-beta) (IFN-beta) could counteract the inhibition of natural killer (NK) activity caused by antitumor agents. Peripheral blood lymphocytes (PBL) were incubated with different antitumor agents alone or in combination with IFN-beta for 3 days and then tested in a cytotoxicity assay against the K562 cell line. The following drugs were used, all of which caused a dose-dependent inhibition of NK activity: etoposide, camptothecin, doxorubicin, cis-DDP, tallimustine, and L-PAM. Concomitant treatment with (1000 U/ml) IFN-beta counteracted the inhibitory effect of etoposide and camptothecin but had no consistent effect on the inhibition mediated by the other drugs. Mean values of inhibition of NK activity at 1 microM camptothecin was 48%+/-3.4% and with IFN-beta was 10%+/-4.9%. With 100 microM etoposide, mean value of inhibition was 78%+/-3.3%, and with IFN-beta, it was 18%+/-1.5%. Cell viability, assessed by vital dye exclusion, and drug uptake, assessed with radiolabeled etoposide, were similar in cells treated with or without IFN-beta. The protective effect of IFN-beta on NK function was rather selective, as IFN-beta did not counteract the drug-mediated inhibition of PBL proliferation when stimulated by phytohemagglutinin (PHA). Other cytokines, IFN-alpha, IFN-gamma, and interleukin-2 (IL-2), had similar protective effect, although IFN-beta, was slightly more potent. On the other hand, IL-6, a cytokine sharing some properties with IFNs was ineffective. Camptothecin inhibited the expression of mRNA for granzyme B, a lytic protein involved in lymphoid-mediated cytotoxicity. Combined treatment with IFN-beta restored-at least in part-the transcription of granzyme B mRNA. These results show that the immunosuppressive effect of some antitumor agents could be partly counteracted by treatment with IFN-beta.

Antineoplastic Agents↗
PubMed1998

hMLH1 and hMSH2 expression and BAX frameshift mutations in ovarian cancer cell lines and tumors.

The expression of mismatch repair proteins hMSH2 and hMLH1 was investigated in human ovarian cancer cell lines and in biopsies of ovarian carcinomas obtained from 20 patients undergoing surgical operation. By Western blotting analysis hMSH2 protein was detected in all the tumor samples analyzed and in eight out of nine human ovarian cancer cell lines, while hMLH1 was undetectable in four out of 20 ovarian tumors and in five out of nine human ovarian cancer cell lines analyzed. The possible presence of frameshift mutations in the BAX gene, which contains a sequence of eight contiguous guanines in its third exon, was tested in all the samples. All the cell lines presented the normal alleles for the BAX gene while only in one of the tumor samples a heterozygous frameshift mutation was found. The frameshift mutation was associated to a low, almost undetectable, level of BAX protein which was instead present at much higher levels in all the other samples investigated. The results indicate that frameshift mutations in the BAX gene, possibly arising as a consequence of microsatellite instability (detectable in these tumors), is detectable in human ovarian cancer although quantitatively it does not appear to be a major determinant of the low apoptotic response to chemotherapy observed in ovarian cancer cells.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Sequence-specific DNA alkylation of novel tallimustine derivatives.

Three different groups of analogs of the sequence-specific minor groove alkylator tallimustine (2) have been synthesized and investigated. Within group I, the dibromo nitrogen mustard (3) and the half-mustard (4) are more cytotoxic (IC50 = 0.6 and 40 ng/ml respectively) than tallimustine (IC50 = 50.3 ng/ml) against L1210 cells with high reactivity against the region 5'-TTTTGA. The diol derivative (6) and the difluoro nitrogen mustard (5) were not cytotoxic against L1210 cells and did not show any detectable DNA alkylation. The two compounds modified in the propionamidine terminus (7 and 8, group II), showed lower cytotoxic potency (IC50 = 130 and 94 ng/ml respectively) against L1210 cells than tallimustine (IC50 = 50.3 ng/ml) and a loss of in vitro sequence specificity for DNA alkylation. Considering the compounds in which the pyrrole rings were replaced by one (9) or two (10) pyrazole rings, compound 9 was not significantly cytotoxic against L1210 cell line and was apparently unable to produce alkylation on the DNA fragments tested, while compound 10 showed decreased cytotoxicity (IC50 = 114 ng/ml) and no modification in the pattern and intensity of DNA alkylation. The data obtained in this work suggest that it is possible to increase tallimustine potency by modifying the nitrogen mustard moiety. Moreover, the sequence specificity of DNA alkylation appears to be affected by the modification of the propionamidino moiety but not by the isosteric modification of the pyrrole rings. The correlation between cytotoxicity and alkylation pattern suggests that tallimustine exerts its cytotoxicity through DNA sequence-specific alkylation of the adenine located in the sequence 5'-TTTTGA.

Animals↗
PubMed1998

Ecteinascidin-743, a new marine natural product with potent antitumor activity on human ovarian carcinoma xenografts.

The antitumor activity of ecteinascidin (ET)-743, a novel marine natural product, was evaluated against a panel of human ovarian carcinoma xenografts characterized by different malignant behaviors and drug responsiveness in nude mice. These tumor models included three xenografts transplanted s.c. (HOC18, HOC22-S, and MNB-PTX-1) into nude mice, representing different levels of sensitivity to cisplatinum (DDP), which was used as reference drug for ovarian carcinoma, and two other xenografts (HOC22 and HOC8), which are highly malignant in the peritoneal cavity of nude mice, representing the growth pattern of this neoplasm. At the maximum tolerated dose of 0.2 mg/kg using an intermittent schedule of one i.v. injection every 4 days, ET-743 was highly active against HOC22-S (sensitive to DDP), inducing long-lasting, complete regressions, and against HOC18 (marginally sensitive to DDP), inducing partial tumor regressions. Moreover, significant growth delay was observed in mice bearing late-stage HOC18 tumor (400-mg tumor weight; nonresponsive to DDP). ET-743, however, was not active against MNB-PTX-1, a tumor that is highly resistant to chemotherapy, including DDP. In the i.p. ovarian carcinoma xenograft model, ET-743 at the maximum tolerated dose induced complete tumor remissions in all mice bearing HOC22 tumor, with 25% histopathologically confirmed cures, and produced marginal tumor growth delay against HOC8. These results indicate that ET-743 is a potent drug against ovarian carcinoma xenografts, being equally as active or more efficacious than DDP in the same tumor line. Our findings with human ovarian carcinoma xenografts justify clinical assessment of this drug with this tumor target.

Animals↗
PubMed1998

Taxoids in combination with anthracyclines and other agents: pharmacokinetic considerations.

The combination in clinical trials of taxoids with doxorubicin has focused attention on possible drug interactions. One specific finding requiring explanation is the relative lack of cardiotoxicity of the docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France)/doxorubicin combination compared with that of the paclitaxel/doxorubicin combination. Data in mice demonstrate that epirubicin concentrations in cardiac tissue 24 hours after treatment are approximately doubled by the coadministration of paclitaxel. This effect appears to be less marked with docetaxel administered in its normal polysorbate vehicle or when the drug is given in Cremophor EL (Sigma, St Louis, MO). Both Cremophor EL or polysorbate appear to cause an increase in epirubicin tissue levels, although the levels were less than those seen with paclitaxel. Pharmacokinetic data from women being treated with combination therapy for advanced breast cancer demonstrate that the administration of docetaxel following doxorubicin does not alter doxorubicin's area under the plasma concentration-time, curve, maximum plasma concentration, or time until maximum plasma concentration is reached. However, the area under the curve of docetaxel is significantly increased by the prior administration of doxorubicin. These findings may explain both the low cardiotoxicity and the high clinical efficacy of the docetaxel/doxorubicin combination. Phase I clinical trials of combinations in which docetaxel was used together with vinorelbine, ifosfamide, or 5-fluorouracil have shown no evidence of relevant pharmacokinetic interactions.

Animals↗
PubMed1997

Glutathione S-transferase activity and glutathione content in human bladder carcinoma associated with schistosomiasis: comparison with uninvolved surrounding tissues.

Glutathione (GSH), glutathione S-transferase (GST) activity and GSTpi expression were measured in 10 human bladder tumors and adjacent uninvolved specimens from Egyptian patients with a history of schistosomal infection. GSH was higher in the tumor than in surrounding uninvolved tissue (not significant). Total GST activity per mg tissue protein and GSTpi expression were higher in tumor tissues (P < 0.05) than in uninvolved tissues. There was a positive correlation between GST activity and GSH content and between total GST activity and GSTpi expression in both tumor and uninvolved tissues.

Adult↗
PubMed1997

Hematopoietic toxicity and cell cycle perturbations induced by new DNA minor groove-alkylating agents.

Some new alkylating agents which bind to the minor groove of DNA and have sequence-specific patterns of alkylation have shown anti-neoplastic activity in pre-clinical systems. Two of them, carzelesin and tallimustine, are now in phase II. Considering the severe dose-limiting bone marrow toxicity of both these drugs in clinical use, it was of interest to investigate the mechanism of their myelotoxicity in a detailed pre-clinical study and compare it with a conventional alkylating agent, such as melphalan. The origin and progression of the myelotoxicity of carzelesin, tallimustine and melphalan were investigated comparatively in mice, combining data on bone marrow and peripheral blood cellularity with data on the proliferative activity of bone marrow cells, obtained by in vivo administration of bromodeoxyuridine. Significant differences were found between the hematopoietic response to the 3 drugs, though all caused severe leukopenia. Carzelesin induced a short-term increase in myeloid proliferative activity, which prevented the high leukocytopenia on day 3 observed with the other drugs. However, when this effect was exhausted, a second nadir was seen in peripheral blood, with a new wave of cell proliferation of all lineages in the bone marrow. Reconstruction of the lymphoid lineage was slow for all 3 drugs but particularly difficult with high-dose tallimustine. In general, the hematopoietic system response to tallimustine was dampened, with no overshoots, suggesting either lasting effects or extensive cytotoxicity from the early to late precursors of all lineages.

Animals↗
PubMed1997

p21WAF1-derived peptides linked to an internalization peptide inhibit human cancer cell growth.

We tested the ability of synthetic peptides derived from p21(WAF1), fused to the internalization peptide sequence derived from Antennapedia, to inhibit the growth of cancer cells in two human ovarian cancer cell lines expressing wild-type p53 or not. Two fused peptides corresponding to p21(WAF1) regions 17-33 and 63-77 inhibited cell growth in both cell lines while the same peptides without the internalization sequence were inactive. The fused peptides prevented growth at concentrations which inhibited cyclin-dependent kinase 2 and cdc2 activity, thus demonstrating that the peptides act by mimicking the action of p21(WAF1) on kinases. This study illustrates the potential pharmacological use of small peptides fused with the Antennapedia internalization sequence in proliferative disorders. The approach may be extended to other diseases in which cell penetration of a peptide may be of therapeutic benefit. More stable drug-like molecules with better pharmacological properties could be designed based on the results obtained with peptides.

Antennapedia Homeodomain Protein↗