Dennis Heath

To determine the maximum tolerated dose and pharmacokinetics of topotecan when administered by the intraperitoneal route. A dose-escalating Phase I trial was conducted in which fifteen % of the total dose was given as an intraperitoneal bolus in two litres of D5W and the remainder was given as a continuous intraperitoneal infusion over 24 hours. Treatments were given every 21 days. Pharmacokinetic analyses were performed at the recommended phase II dose. Seventeen patients received a total of 43 cycles at 21-day intervals. The maximum tolerated dose was 4 mg/m2 and acute dose-limiting toxicity was neutropenia. Other toxicities included leukopenia, anemia, emesis, fever, and abdominal pain. Although no objective responses were achieved, five of ten patients with ascites had a decrease in fluid accumulation with administration of intraperitoneal topotecan. The recommended phase II dose is 3 mg/m2. Pharmacokinetic analysis performed at a dose of 3 mg/m2 demonstrated that elimination fr...

Intraperitoneal (i.p.) administration of chemoterapeutic agents results in greater total drug exposures in the peritoneal cavity than in plasma. A study on the drug exposure for i.p. lymphatics of pigs, receiving 5-fluorouracil (5-FU), etoposide (VP-16) and carboplatin (CBDCA) by the i.p. route was conducted. Drug concentrations in peritoneal fluid, plasma, and thoracic duct lymph were monitored over the ensuing 3 h. 5-FU appeared rapidly in thoracic duct, lymph and plasma. The lymph concentration declined after 20 min while the plasma concentration remained stable. CBDCA reached a stable concentration in lymph and plasma after 60 min. VP-16 peaked in the lymph after 20 min, whereas the plasma concentration continued to rise for 150 min; the peritoneal half-life for VP-16 was too long for clearance to be defined. Total drug exposure (AUC) was for 5-FU 5.7-fold greater for lymph than for plasma and for CBDCA equal in both compartments. VP-16 had a 2.1-fold higher AUC for lymph than for plasma. The results indicate that the i.p. route of administration results in a greater exposure of the lower thoracic duct lymph than the plasma to 5-FU, produces only a marginally increased exposure to VP-16, and results in no difference for CBDCA. The efficacy of 5-FU is a function of total drug exposure. The results reported provide a strong rationale for evaluating the adjuvant use of i.p. 5-FU in colorectal and gastric carcinoma.

The hASNA-I is a novel human arsenite-stimulated ATPase identified as the human paralogue of the ATPase component of the arsenite efflux system in E. coli. The hASNA-I has distinct biochemical properties and a dual nuclear and cytoplasmic distribution. Immunohistochemical staining showed a distinct pattern of hASNA-I expression in cells within normal tissues, and its overexpression in breast cancer. Recently, the yeast two-hybrid system has identified hASNA-I as a cellular partner of metallothionein II suggesting an additional role in Zn homeostasis and cellular detoxification. This report describes the assignment of hASNA-I to human chromosome 19 by somatic-cell hybrid PCR mapping, the isolation of a chromosome 19-specific cosmid clone, and the genomic structure and exon-intron boundaries of hASNA-I. Our results indicate that the coding region of hASNA-I consists of 4 exons spanning 6 kb on band 19q13.3. These data will facilitate molecular analysis of the role of hASNA-I in human disease.

Curcumin, derived from the rhizome curcuma longa, is one of the primary ingredients in turmeric and curry powders that are used as spices in Middle Eastern and Asian countries, especially on the Indian subcontinent. More recently, laboratory studies have demonstrated that dietary curcumin exhibits various biological activities and significantly inhibits colon tumorigenesis and tumor size in animals. Curcumin displays both anti-inflammatory and antioxidant properties, giving it the potential to be considered in the development of cancer preventive strategies and applications in clinical research. Experimental studies have shown the biological activities of the compound, but much more information on pharmacokinetics, bioavailability, and food content are needed. Whether the amount of curcumin in turmeric and curry powders is sufficient to suggest effects on biological activities and cancer risk is unknown. To determine and compare the quantitative amounts of curcumin that are present in several brands of turmeric and curry powders, a high performance liquid chromatography technique was used to analyze 28 spice products described as turmeric or curry powders and two negative controls. Pure turmeric powder had the highest curcumin concentration, averaging 3.14% by weight. The curry powder samples, with one exception, had relatively small amounts of curcumin present, and the variability in content was great. The curcumin content of these seasoning products that are consumed as a component of the diet should be considered in evaluating baseline tissue concentration and response to curcumin supplementation, which is under study in chemoprevention trials.

The arsenite-stimulated human ATPase (hASNA-I) protein is a distinct human ATPase whose cDNA was cloned by sequence homology to the Escherichia coli ATPase arsA. Its subcellular localization in human malignant melanoma T289 cells was examined to gain insight into the role of hASNA-I in the physiology of human cells. Immunocytochemical staining using the specific anti-hASNA-I monoclonal antibody 5G8 showed a cytoplasmic, perinuclear, and nucleolar distribution. Subcellular fractionation indicated that the cytoplasmic hASNA-I was soluble and that the perinuclear distribution was due to association with the nuclear membrane rather than with the endoplasmic reticulum. Its presence in the nucleolus was confirmed by showing colocalization with an antibody of known nucleolar specificity. Further immunocytochemical analysis showed that the hASNA-I at the nuclear membrane was associated with invaginations into the nucleus in interphase cells. These results indicate that hASNA-I is a paralogue of the bacterial ArsA protein and suggest that it plays a role in the nucleocytoplasmic transport of a nucleolar component.

Arsenite resistance in bacteria is mediated by an efflux pump composed of thearsAandarsBgene products. We have isolated the human homolog of the bacterialarsA(hARSA-I), a member of the ATPase superfamily with no transmembrane domain. Southern and Northern analyses indicated the presence of two cross-hybridizing genes in the human genome and expression ofhARSA-Iin many tissues. A rabbit antiserum raised against a glutathione-S-transferase (GST)/hARSA-I fusion protein identified two cross-reacting proteins of 37 and 42 kDa by Western analysis in two different human cell lines. Overexpression ofhARSA-Iin the embryonal human kidney 293 cell line was accompanied by overproduction of the 37-kDa protein. Biochemical analysis using the GST/hARSA-I fusion protein indicated that hARSA-I is an ATPase analogous to the bacterial ArsA. Thus,hARSA-Iis a new eukaryotic member of a highly conserved ATP-binding superfamily of proteins.

Platinum-containing drugs enter the cell slowly and have a poor tissue penetration. Increasing the permeability of the cell membrane might increase the intracellular drug concentration. Digitonin, a detergent that increases cell permeability by binding to cholesterol molecules in the cell membrane, can increase cisplatin accumulation and reduce tumour growth in vitro. The aim of this study was to determine whether digitonin could increase the efficacy of carboplatin (CBDCA) in vivo. In LH rats, a hepatoma was implanted in the liver. At 7 days after implantation, digitonin (or saline in the control group) was infused via the hepatic artery and, 10 min later, CBDCA was injected. Biopsies from the tumour and liver parenchyma were obtained after 1 h. The concentration of platinum measured in the liver tumours was higher in the digitonin group than in the control groups. In the liver parenchyma the concentrations were of the same magnitude. Measured with the 133Xe-clearance technique, digitonin did not alter the tumour blood flow. Digitonin enhanced the tumour-growth-retarding effect of CBDCA given intra-arterially at 5 mg/kg but not at 25 mg/kg. No increase in toxicity was observed for digitonin given together with CBDCA at 5 mg/kg. Systemic administration of CBDCA was not influenced by digitonin. These findings demonstrate that pretreatment with digitonin increases the tumour uptake of CBDCA and potentiates the cytotoxic effect of CBDCA.

A group of 23 patients with advanced head and neck cancer were treated with highly selective intra-arterial (IA) cisplatin 150 mg/m2 delivered rapidly through microcatheters. The systemic effects of cisplatin were neutralized by concurrent administration of sodium thiosulfate. Two-to-threefold higher tumor platinum contents were detected in tumor biopsies after selective IA cisplatin administration compared to historical controls (treated with 100 mg/m2 IA). Cisplatin-induced DNA modification in human tumor biopsies was quantitated using the antiserum NKI-A59. High levels of cisplatin DNA adducts were detected which correlated linearly with the tumor platinum content (r2 = 0.62). The addition of radiotherapy to this high dose intensity cisplatin treatment resulted in a 92% complete response (CR) rate (12 of 13 patients achieved a CR). Since no difference in tumor platinum content was detected between patients receiving or not receiving radiotherapy (13 and 10 patients, respectively), but the response rate was substantially different (12 CR and 1 partial response with radiotherapy versus 6 partial and 4 non-responders without radiotherapy), these data suggest that the high platinum levels achieved by selective IA infusion were sufficient to produce enough interaction with radiotherapy to cause a 92% CR rate. Whether this interaction is additive or synergistic is as yet unclear.

Curcumin is a polyphenolic compound derived from the plant Curcuma Long Lin that has been demonstrated to have antioxidant and anti-inflammatory effects as well as effects on reducing beta-amyloid aggregation. It reduces pathology in transgenic models of Alzheimer's disease (AD) and is a promising candidate for treating human AD. The purpose of the current study is to generate tolerability and preliminary clinical and biomarker efficacy data on curcumin in persons with AD. We performed a 24-week randomized, double blind, placebo-controlled study of Curcumin C3 Complex(®) with an open-label extension to 48 weeks. Thirty-six persons with mild-to-moderate AD were randomized to receive placebo, 2 grams/day, or 4 grams/day of oral curcumin for 24 weeks. For weeks 24 through 48, subjects that were receiving curcumin continued with the same dose, while subjects previously receiving placebo were randomized in a 1:1 ratio to 2 grams/day or 4 grams/day. The primary outcome measures were incidence of adverse events, changes in clinical laboratory tests and the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog) at 24 weeks in those completing the study. Secondary outcome measures included the Neuropsychiatric Inventory (NPI), the Alzheimer's Disease Cooperative Study - Activities of Daily Living (ADCS-ADL) scale, levels of Aβ1-40 and Aβ1-42 in plasma and levels of Aβ1-42, t-tau, p-tau181 and F2-isoprostanes in cerebrospinal fluid. Plasma levels of curcumin and its metabolites up to four hours after drug administration were also measured. Mean age of completers (n = 30) was 73.5 years and mean Mini-Mental Status Examination (MMSE) score was 22.5. One subject withdrew in the placebo (8%, worsened memory) and 5/24 subjects withdrew in the curcumin group (21%, 3 due to gastrointestinal symptoms). Curcumin C3 Complex(®) was associated with lowered hematocrit and increased glucose levels that were clinically insignificant. There were no differences between treatment groups in clinical or biomarker efficacy measures. The levels of native curcumin measured in plasma were low (7.32 ng/mL). Curcumin was generally well-tolerated although three subjects on curcumin withdrew due to gastrointestinal symptoms. We were unable to demonstrate clinical or biochemical evidence of efficacy of Curcumin C3 Complex(®) in AD in this 24-week placebo-controlled trial although preliminary data suggest limited bioavailability of this compound. ClinicalTrials.gov Identifier: NCT00099710.