A phase I and pharmacologic study of pyrazoloacridine (NSC 366140) and carboplatin in patients with advanced cancer

Background: Pyrazoloacridine (PZA) is thefirst of a new class of rationallysynthesized acridine derivatives to undergoclinical testing as an anticancer agent. We previously demonstrated cytotoxicsynergy between combinations of PZA andplatinum compounds. Subsequent studiesrevealed that PZA inhibits removal ofplatinum-DNA adducts in cultured A549cells. Based on these results, weundertook a phase I study of thecombination of PZA and carboplatin (CBDCA). Patients and methods: Twenty-eightpatients received 76 28-day courses (median2.5, range 1–6) of CBDCA (30-minuteinfusion) followed by PZA (3-hourinfusion), through six dose levels [PZA/CBDCA] (200/AUC 3,400/AUC 3, 400/AUC 4,400/AUC 5, 500/AUC 5, 600/AUC5 mg/m²/AUC). Pharmacokineticanalyses were performed to evaluate thedisposition of PZA. Retention ofplatinum-DNA adducts in peripheral bloodmononuclear cells of patients was alsoevaluated. Results: The most common anddose-limiting toxicity wasmyelosuppression, consisting of neutropeniaand leukopenia. Non-hematologic toxicitiesof anorexia, nausea and stomatitis weremild to moderate. In six patientsevaluated at the MTD, CBDCA did not appearto affect the pharmacokinetics of PZA. Onepatient with malignant melanoma had apartial response. Disease stabilizationfor greater than 4 courses of treatmentoccurred in 4 patients. Conclusion: The combination of PZAand CBDCA was well tolerated and may haveutility in some tumor types.     

Evaluation of pyrazoloacridine in patients with advanced pancreatic carcinoma

Purpose: Pyrazoloacridine (PZA) is an acridine derivative selected for clinical development because of broad preclinical antitumor activity and solid tumor selectivity. Phase I evaluations with PZA have demonstrated predictable toxicity and suggested clinical efficacy. A phase II trial in patients with previously untreated advanced pancreatic cancer was conducted. Methods: PZA was administered at a dose of 750 mg/m² intravenously over 3 hours every 21 days. Seventeen patients were treated receiving a total of 46 courses of PZA. Results: Of the 15 patients evaluable for response, no responses were observed (0% response rate, 95% confidence interval 0–22%). Major toxicities directly attributable to PZA included moderate neutropenia and mild neurotoxicity. Conclusion: PZA at this dose and schedule of administration was inactive in patients with pancreatic carcinoma.     

Phase II trial of pyrazoloacridine in advanced non-small cell carcinoma of the lung--a Kansas Cancer Institute and Thompson Cancer Survival Center Study

Background: More active agents areneeded in the treatment of metastaticnon-small cell lung cancer. Pyrazoloacridine (PZA) is a 9-methoxyacridine compound containing a reducible5-nitro substituent. Although themechanism of action of PZA is unknown, theacridine compounds are known to causecytotoxicity by interaction with DNA andRNA. Methods: Eighteen patients withmetastatic non-small cell lung carcinomawere treated with pyrazoloacridine.Pyrazoloacridine was administered as athree-hour infusion at 750 mg/M² every21 days. Results: There were no objectiveresponses. One patient maintained stabledisease for 20 months. Median survival was4.8 months. The primary toxicity wasgranulocytopenia with 5 patientsexperiencing severe infections. Conclusions: Pyrazoloacridine has nodemonstrable activity in patients withmetastatic non-small cell carcinoma of thelung when given at this dose andschedule.     

A phase II study of pyrazoloacridine in patients with advanced renal cell carcinoma

The aim of this study was to determine the antitumor activity of pyrazoloacridine in patients with renal cell carcinoma. Eligible patients had advanced renal cell carcinoma with bidimensionally measurable disease, a Karnofsky performance status of at least 70, life expectancy of greater than three months, no prior treatment with chemotherapy, and no evidence of brain metastases. Patients were treated intravenously with 750 mg/m² every three weeks. Twelve patients were enrolled in this study and all were evaluable for response and toxicity. Of the twelve patients, no major responses were achieved. Toxicity was mild, with three patients requiring a 20% dose reduction. At the dose and schedule used in this trial, pyrazoloacridine is inactive in renal cell carcinoma.     

Phase I/II trial of pyrazoloacridine and carboplatin in patients with recurrent glioma: A North Central Cancer Treatment Group trial

Purpose: Novel therapeutic agents in the treatment of recurrent gliomas are urgently needed. Pyrazoloacridine (PZA), a rationally synthesized acridine derivative, has shown promising antitumor activity against glioma lines in combination with platinum compounds. This phase I/II trial of the PZA/carboplatin combination in recurrent glioma patients consisted of two phase I studies (studies 1 and 2) and a phase II trial (study 3). The objectives of studies 1 and 2 were to (a) assess the safety and toxicity and to establish the phase II dose of the pyrazoloacridine/carboplatin combination for recurrent glioma patients on P450 inducing anticonvulsants, and (b) to confirm the phase II dose for patients not on P450 inducing anticonvulsants. The primary objectives of study 3 were to determine the efficacy of the pyrazoloacridine/carboplatin combination in patients with recurrent gliomas, to further assess the toxicity of the combination, and to evaluate the impact of enzyme-inducing anticonvulsants on the pyrazoloacridine metabolism. Experimental design: Both carboplatin and pyrazoloacridine were administered intravenously every 28 days. Treatment was continued until unacceptable toxicity, tumor progression or patient withdrawal. Results: 14 patients were treated in the two phase I studies and 32 patients in the phase II trial. The phase II dose of the combination was PZA 400 mg/m² and carboplatin AUC of 5 every 28 days. Neutropenia (4 patients) and dyspnea (1 patient) was the dose limiting toxicity in the phase I studies. In the phase II trial, the most frequent toxicity was myelosuppression with grade 3 and 4 hematologic adverse events being observed in 22 and 19% of the patients, respectively. The antitumor activity of this regimen was limited; the response rate in the phase II trial was 0%, (95% CI:0–11%) while 12 of the 32 patients (38%) had stable disease with a median duration of 2 months. The percentage of phase II patients who were progression free at three months was 22% and at six months was 16%. Median survival from study entry was 5.0 months for phase I patients and 5.8 months for phase II patients. Pharmacokinetic analysis performed in 8 phase I patients demonstrated no significant impact of the enzyme-inducing anticonvulsants on the pharmacokinetics of pyrazoloacridine. Conclusions: The phase II dose of the pyrazoloacridine/carboplatin combination is pyrazoloacridine 400 mg/m² in combination with carboplatin AUC of 5. Antitumor activity in patients with recurrent gliomas was limited. Initial disease stabilization occurred in approximately 38% of the patients, with median duration of 2 months. Enzyme-inducing anticonvulsants did not affect the pyrazoloacridine metabolism.     

ZD1839 ('Iressa') as an anticancer agent

ZD1839 ('Iressa') is an orally active, selective epidermal growth factor receptor-tyrosine kinase inhibitor which blocks signal transduction pathways implicated in the proliferation and survival of cancer cells and other host-dependent processes promoting cancer growth. In preclinical studies, ZD1839 produced reversible growth inhibition and growth delay in a wide range of tumour cell lines and human tumour xenografts. Moreover, this activity was enhanced when ZD1839 was coadministered with cytotoxic agents. Preliminary results from phase I trials in patients with advanced disease and a wide variety of tumour types suggest that ZD1839 has an acceptable tolerability profile and promising clinical efficacy, particularly in non-small cell lung cancer (NSCLC). ZD1839 is currently in phase III clinical development for the treatment of advanced NSCLC. In addition, further trials are ongoing or planned in a number of other tumour types.     

A phase I and pharmacologic study of pyrazoloacridine and cisplatin in patients with advanced cancer

Pyrazoloacridine (PZA, NSC366140, PD115934) is an acridine derivative currently undergoing clinical evaluation. In preclinical testing, PZA has shown selectivity for solid tumor cell lines, activity in hypoxic, noncycling, and multidrug-resistant cell lines, and synergy with cisplatin in a variety of lung cancer cell lines. In early phase I clinical studies PZA has shown modest activity in ovarian, cervical, and colon cancer. The purpose of the present study was threefold: to determine the maximally tolerated doses of the combination of PZA (3-h infusion) and cisplatin administered with and without Filgrastim (G-CSF) (Amgen, Thousand Oaks, CA) every 3 weeks in untreated or minimally pretreated patients, to describe and quantify the clinical toxicities of combination chemotherapy with PZA and cisplatin, and to evaluate the effects of drug sequencing on the toxicity profile and pharmacologic behavior of PZA. The starting doses in this dose-escalation trial were PZA 400 mg/m² as a 3-h intravenous infusion and cisplatin 50 mg/m² as a 1 mg/min intravenous infusion. The sequence of drugs was alternated with each successive course in each patient treated. Twenty-one patients with refractory solid tumors received 43 courses of therapy through four dose levels. Neutropenia was dose-limiting and defined the maximum tolerated dose of PZA 400 mg/m² and cisplatin 50 mg/m² without G-CSF support. With G-CSF support, nausea and vomiting were dose-limiting. The maximum tolerated and recommended doses for further study of this combination are PZA 600 mg/m² over 3 h and cisplatin 50 mg/m² followed by G-CSF support. Pharmacokinetic analysis showed that sequence does not impact on the pharmacokinetics of PZA when given in combination with cisplatin.     

Guanidine-reactive agent phenylglyoxal induces DNA damage and cancer cell death

BackgroundDNA-damaging compounds (e.g., alkylating agents, cytotoxic antibiotics and DNA topoisomerase poisons) are the most widely used anticancer drugs. The inability of tumor cells to properly repair some types of DNA damage may explain why specific DNA-damaging drugs can selectively kill tumor cells. Phenylglyoxal is a dicarbonyl compound known to react with guanidine groups such as that of the DNA base guanine, therefore suggesting that phenylglyoxal could induce DNA damage and have anticancer activity.MethodsCellular DNA damage was measured by the alkaline comet assay and the γH2AX focus assay. Formation of topoisomerase I- and topoisomerase II-DNA complexes was assessed by the TARDIS assay, an immunofluorescence technique that employs specific antibodies to DNA topo I or topo II to detect the protein covalently bound to the DNA in individual cells. Cell growth inhibition and cytotoxicity were determined by XTT, MTT and clonogenic assays. Apoptosis was assessed by the Annexin V flow cytometry assay.ResultsPhenylglyoxal induced cellular DNA damage and formation of high levels of topoisomerase I- and topoisomerase II-DNA complexes in cells. These topoisomerase-DNA complexes were abolished by catalase pretreatment and correlated well with the induction of apoptosis. Phenylglyoxal-induced cell death was partially prevented by catalase pretreatment and was higher in lung cancer cells (A549) than in normal lung fibroblasts (MRC5). Mammalian cell lines defective in nucleotide excision repair (NER), homologous recombination (HR) and non-homologous end joining (NHEJ) were more sensitive to phenylglyoxal than parental cells; this suggests that phenylglyoxal may induce bulky distortions in the shape of the DNA double helix (which are repaired by the NER pathway) and DNA double-strand breaks (which are repaired by HR and NHEJ).ConclusionsThis report shows that phenylglyoxal is a new DNA-damaging agent with anticancer activity, and suggests that tumor cells with defects in NER, HR and NHEJ may be hypersensitive to the cytotoxic activity of phenylglyoxal.     

铂类抗癌药物脂质体的研究进展*

目前在药物靶向性给药系统中，脂质体是最成熟和最先进的药物载体之一。脂质体已应用于许多细胞毒抗癌药物的靶向剂型的开发中，例如多柔比星（阿霉素）、紫杉醇和铂类抗癌药物。脂质体可以减少药物的毒副作用，提高抗癌疗效，甚至克服顺铂耐药性。现综述铂类抗癌药物脂质体的临床前和临床研究的进展情况。     

青蒿素类衍生物抗肿瘤研究进展

青蒿素类药物是很好的抗疟药物,近年来大量体内、外研究显示青蒿素具有良好的抗肿瘤活性。大多数肿瘤细胞表面有高浓度的转铁蛋白受体,因此与正常细胞相比,细胞内含有更多的亚铁离子,青蒿素与亚铁离子反应生成自由基,可以选择性的杀伤肿瘤细胞。G1期细胞的转铁蛋白受体表达和铁离子摄入都显著增多,青蒿素类药物在此期诱导细胞凋亡,其具体作用靶点和机制还有待进一步研究,青蒿素衍生物还具有抗肿瘤血管生成活性。将青蒿素类药物与转铁蛋白上的糖基共价结合的复合体,可以将铁离子和青蒿素同时摄入肿瘤细胞,增强了青蒿素的高效性和靶向性。     

Lycopene: a review of its potential as an anticancer agent

Dietary chemoprevention has emerged as a cost effective approach to control most prevalent chronic diseases including cancer. In particular, tomato and tomato products are recognised to confer a wide range of health benefits. Epidemiological studies have provided evidence that high consumption of tomatoes effectively lowers the risk of reactive oxygen species (ROS)-mediated diseases such as cardiovascular disease and cancer by improving the antioxidant capacity. Tomatoes are rich sources of lycopene, an antioxidant carotenoid reported to be a more stable and potent singlet oxygen quenching agent compared to other carotenoids. In addition to its antioxidant properties, lycopene shows an array of biological effects including cardioprotective, anti-inflammatory, antimutagenic and anticarcinogenic activities. The anticancer activity of lycopene has been demonstrated both in in vitro and in vivo tumour models. The mechanisms underlying the inhibitory effects of lycopene on carcinogenesis could involve ROS scavenging, upregulation of detoxification systems, interference with cell proliferation, induction of gap-junctional communication, inhibition of cell cycle progression and modulation of signal transduction pathways. This review outlines the sources, structure, absorption, metabolism, bioavailability and pharmacological properties of lycopene with special reference to its antioxidant and anticarcinogenic effects.     

Novel arylsulfoanilide-oxindole hybrid as an anticancer agent that inhibits translation initiation

Structure-activity relationship studies of substituted arylsulfoanilides as antiproliferatives, which are mediated by the partial depletion of intracellular Ca(2+) stores, resulted in the identification of compounds with micromolar activity against lung cancer cells in a growth inhibition assay. Incorporating the substitution pattern of the best arylsulfoanilides onto the 3-phenyloxindole scaffold resulted in a potent arylsulfoanilide-oxindole hybrid, 27. Compound 27 inhibits cancer cell growth by partial depletion of intracellular Ca(2+) stores and phosphorylation of eIF2alpha.     

HER dimerization inhibitors: developing pertuzumab as an anticancer agent in women's oncology

Background: Pertuzumab is a novel monoclonal antibody that blocks the dimerization domain of the human epidermal growth factor receptor (HER)-2/neu receptor, disabling its ability to form heterodimers with the other members of its family. Objective: We review the background and scientific rationale, but more specifically cover current clinical trial outcomes of pertuzumab in solid tumors, with an emphasis on the work completed in women's cancers. Methods: Clinical trial results published or presented at national meetings are included in this review. Results: Pertuzumab shows promising activity with trastuzumab in the treatment of metastatic breast cancer. The results in ovarian cancer have been limited thus far but a post hoc analysis of the results of a completed randomized Phase II trial of gemcitabine with or without pertuzumab suggests that low HER3 levels may mark a group of women who may benefit from the addition of pertuzumab to chemotherapy. Conclusions: The efficacy of pertuzumab independent of HER-2/neu overexpression remains under investigation. Still, the benefits seen in HER-2/neu positive breast cancer is encouraging. Work in ovarian cancer remains preliminary but the possibility of using pertuzumab in a targeted population with low HER3 levels warrants further evaluation.     

Paclitaxel as an anticancer agent: isolation,activity, synthesis and stability

Paclitaxel is isolated from the Pacific yew. It can be obtained from the European yew, but only after chemical modification of the isolated compound by a semi-synthesis procedure. The procedure for total synthesis of paclitaxel is very complicated, involving multiple steps, and the yields of paclitaxel are meagre. This substance is also a metabolite of certain kinds of fungus. The microbiological pathway for producing paclitaxel compared with isolation from plant material involves shorter procuction times but a small yield. Cyclodextrins are usually used for improving the solubility of paclitaxel in aqueous media, with polymeric and other substances added. Paclitaxel has anticancer activity and use for preparing the formulations intravenously administrated to patients with tumors. The paclitaxel concentration in these formulations is determined using validated HPLC methods.     

Glutamic acid as anticancer agent: An overview

The objective of the article is to highlight various roles of glutamic acid like endogenic anticancer agent, conjugates to anticancer agents, and derivatives of glutamic acid as possible anticancer agents. Besides these emphases are given especially for two endogenous derivatives of glutamic acid such as glutamine and glutamate. Glutamine is a derivative of glutamic acid and is formed in the body from glutamic acid and ammonia in an energy requiring reaction catalyzed by glutamine synthase. It also possesses anticancer activity. So the transportation and metabolism of glutamine are also discussed for better understanding the role of glutamic acid. Glutamates are the carboxylate anions and salts of glutamic acid. Here the roles of various enzymes required for the metabolism of glutamates are also discussed.     

Current status of cadmium as an environmental health problem

Cadmium is a toxic metal occurring in the environment naturally and as a pollutant emanating from industrial and agricultural sources. Food is the main source of cadmium intake in the non-smoking population. The bioavailability, retention and toxicity are affected by several factors including nutritional status such as low iron status. Cadmium is efficiently retained in the kidney (half-time 10-30 years) and the concentration is proportional to that in urine (U-Cd). Cadmium is nephrotoxic, initially causing kidney tubular damage. Cadmium can also cause bone damage, either via a direct effect on bone tissue or indirectly as a result of renal dysfunction. After prolonged and/or high exposure the tubular injury may progress to glomerular damage with decreased glomerular filtration rate, and eventually to renal failure. Furthermore, recent data also suggest increased cancer risks and increased mortality in environmentally exposed populations. Dose-response assessment using a variety of early markers of kidney damage has identified U-Cd points of departure for early kidney effects between 0.5 and 3 μg Cd/g creatinine, similar to the points of departure for effects on bone. It can be anticipated that a considerable proportion of the non-smoking adult population has urinary cadmium concentrations of 0.5 μg/g creatinine or higher in non-exposed areas. For smokers this proportion is considerably higher. This implies no margin of safety between the point of departure and the exposure levels in the general population. Therefore, measures should be put in place to reduce exposure to a minimum, and the tolerably daily intake should be set in accordance with recent findings.     

Computational studies on effects of MDMA as an anticancer drug on DNA

This research is designed to further understand the effects of the novel drug MDMA on biologic receptor of DNA. The ultimate goal is to design drugs that have higher affinity with DNA. Understanding the physicochemical properties of the drug as well as the mechanism by which it interacts with DNA should ultimately enable the rational design of novel anticancer or antiviral drugs. Molecular modeling on the complex formed between MDMA and DNA presented this complex to be fully capable of participating in the formation of a stable intercalation site. Furthermore, the molecular geometries of MDMA and DNA bases (Adenine, Guanine, Cytosine, and Thymine) were optimized with the aid of the B3LYP/6-31G* method. The properties of the isolated intercalator and its stacking interactions with adenine···thymine (AT) and guanine···cytosine (GC) nucleic acid base pairs were studied with the DFTB method. DFTB method is an approximate version of the DFT method that was extended to cover the London dispersion energy. The B3LYP/6-31G* stabilization energies of the intercalator···base pair complexes were found to be −9.40 and −12.57 kcal/mol for AT···MDMA and GC···MDMA, respectively. Results from comparison of the DFTB method and HF method conclude close results and support each other.     

Digitoxin as an anticancer agent with selectivity for cancer cells: possible mechanisms involved

Accumulating preclinical and clinical data suggest that the cardiac drug digitoxin might be used in cancer therapy. Recent reports have shown that digitoxin can inhibit the growth and induce apoptosis in cancer cells at concentrations commonly found in the plasma of cardiac patients treated with this drug. Several mechanisms have been associated with the anticancer activity of digitoxin, yet at present it is unknown why malignant cells are more susceptible to this cardiac glycoside than non-malignant cells. This report analyses the possible anticancer mechanisms of digitoxin and proposes that the inhibition of glycolysis may be a key mechanism by which this natural product selectively targets cancer cells. Finally, whether or not there is enough evidence to support the clinical evaluation of digitoxin in patients with cancer is discussed.