Expression and localization of the uptake transporters OATP2B1, OATP3A1 and OATP5A1 in non-malignant and malignant breast tissue

Organic anion transporting polypeptides (OATPs, gene family SLCO/SLC21) mediate the uptake of multiple endogenous substances such as estrogens and estrogen metabolites and of several widely prescribed drugs (e.g. statins, antibiotics and anticancer agents) into cells. Since several anticancer agents have been identified as substrates for OATPs, these transporters may also have an impact on cancer treatment. Expression of OATPs has been identified in colon, pancreatic and gastric carcinomas but to date little is known about the expression and localization of OATP family members in non-malignant breast tissue and breast cancer. We therefore analyzed the mRNA expression of all human OATP family members and further evaluated the mRNA amount of the highly-expressed OATPs OATP2B1, OATP3A1 and OATP5A1 in 10 paired samples of normal breast tissue and breast cancer. Furthermore, the tissue-specific localization of these OATPs was investigated. The results demonstrated that the mRNA expression of OATPs in normal and malignant breast tissue shows a high interindividual variability and that no significant differences in the mRNA amount between normal and malignant tissue could be detected. Furthermore, we localized OATP3A1 and OATP5A1 to the plasma membrane of epithelial cells of the lactiferous ducts in normal breast tissue. In breast cancer, both OATPs are highly expressed in the plasma membrane and in the cytoplasm. Since estrogen and estrogen metabolites as well as anticancer agents are substrates for OATPs these results indicate the possibility of OATP-mediated uptake of hormones during breast cancer development and an impact of certain OATPs on chemotherapeutic cancer treatment.     

The Accelerating Access Initiative: experience with a multinational workplace programme in Africa

Problem

A multinational company with operations in several African countries was committed to offer antiretroviral treatment to its employees and their dependants.

Approach

The Accelerating Access Initiative (AAI), an initiative of six pharmaceutical companies and five United Nations’ agencies, offered the possibility of obtaining brand antiretroviral drugs (ARVs) at 10% of the commercial price. PharmAccess, a foundation aimed at removing barriers to AIDS treatment in Africa, helped to establish an HIV policy and treatment guidelines, and a workplace programme was rolled out from September 2001.

Local setting

Private sector employers in Africa are keen to take more responsibility in HIV prevention and AIDS care. An important hurdle for African employers remains the price and availability of ARVs.

Relevant changes

The programme encountered various hurdles, among them the need for multiple contracts with multiple companies, complex importation procedures, taxes levied on ARVs, lack of support from pharmaceutical companies in importation and transportation, slow delivery of the drugs, lack of institutional memory in pharmaceutical companies and government policies excluding the company from access to ARVs under the AAI.

Lessons learned

The launch of the AAI enabled this multinational company to offer access to ARVs to its employees and dependants. The private sector should have access to these discounted drugs under the AAI. A network of local AAI offices should be created to assist in logistics of drugs ordering, purchase and clearance. No taxes should be levied on ARVs.     

IGOB131, a novel seed extract of the West African plant Irvingia gabonensis, significantly reduces body weight and improves metabolic parameters in overweight humans in a randomized double-blind placebo controlled investigation

Background  

A recent in vitro study indicates that IGOB131, a novel seed extract of the traditional West African food plant Irvingia gabonensis, favorably impacts adipogenesis through a variety of critical metabolic pathways including PPAR gamma, leptin, adiponectin, and glycerol-3 phosphate dehydrogenase. This study was therefore aimed at evaluating the effects of IGOB131, an extract of Irvingia gabonensis, on body weight and associated metabolic parameters in overweight human volunteers.     

Efficacy and patterns of failure for locally advanced cancer of the cervix treated with celebrex (celecoxib) and chemoradiotherapy in RTOG 0128

PURPOSE: To determine the efficacy and patterns of initial failure for oral celecoxib, intravenous cisplatin, and 5-fluorouracil and concurrent pelvic radiotherapy in patients with locally advanced cancer of the cervix. METHODS AND MATERIALS: Patients were treated with concurrent 5-fluorouracil and cisplatin chemotherapy and pelvic radiotherapy and brachytherapy. Celecoxib was prescribed at a dose of 400 mg twice daily for 1 year beginning on the first day of radiotherapy. The overall and disease-free survival rates were determined. RESULTS: A total of 84 patients were accrued, of whom 78 were eligible. The estimated 2-year disease-free survival and overall survival rate was 69% and 83%, respectively. Of the 78 patients, 24 had treatment failure: 3 with persistent local disease, 9 local only, 2 regional, 4 distant, 1 regional and distant, 1 local and distant, and 2 with local, regional, and distant disease, and 1 had died of cervical cancer without a reported site of first failure and 1 without evidence of disease. CONCLUSION: At 2 years, the estimated disease-free survival and overall survival rate for patients with advanced cervical cancer who underwent a combination of chemoradiotherapy and celecoxib treatment was 69% and 83%, respectively. Recurrent disease developed in 24 patients, and, of those patients, 18 had a component of locoregional failure as a site of first failure. Thus, locoregional control continues to be problematic after chemoradiotherapy as delivered in our study. The identification of more active biologically targeted therapies is warranted for the treatment of advanced cancer of the cervix.     

Impact of the CYP3A5 genotype on midazolam pharmacokinetics and pharmacodynamics during intensive care sedation

Objective Information is lacking on whether the CYP3A5 genotype affects the disposition and effects of midazolam during the long-term intensive care sedation of patients. This study was undertaken to estimate whether the CYP3A5 genotype can explain a relevant portion of pharmacokinetic interindividual variability. Methods We determined the CYP3A5 genotype in 71 Caucasian patients who underwent long-term sedation during intensive care treatment. We then assessed the relation between the genotype and both the plasma concentrations of midazolam and 1′-OH-midazolam in 645 plasma samples and the simultaneously estimated Ramsay sedation score, both of which were recorded during routine midazolam drug monitoring. Results Eight patients had the CYP3A5*1/*3 genotype and 63 patients the CYP3A5*3/*3 genotype. The concentration–dose ratio [C/D; plasma concentration of midazolam (ng/ml) divided by the rate of infusion (mg/h); expressed as the mean (95% confidence interval)] was 87.4 (70.8, 108.9) for the *3/*3 patients and 79.0 (48.9, 129.0) for *1/*3 patients. The corresponding data for infusion rate (IR; in mg/h), Ramsay score (RS) and the ratio 1′-OH-midazolam concentration/midazolam concentration (ROH) for *3/*3 and *1/*3 patients were IR 7.4 (6.2, 8.6) vs. 11.4 (4.9, 17.9), RS 5.4 (5.2, 5.6) vs. 5.3 (4.2, 6.0) and ROH 0.11 (0.09, 0.13) vs. 0.17 (0.11, 0.26), respectively. Conclusions The CYP3A5*1/*3 genotype did not lead to an apparently lower midazolam concentration/dose ratio or Ramsay score values. As the present sedation procedure during intensive care therapy may be described as a physician closed-loop titration towards Ramsay scores of 4 ± 1, our data do not indicate that prior determination of the genotype will result in better care or economic savings.