Peripheral blood lymphocyte number and phenotype prior to therapy correlate with response in subcutaneously applied rIL-2 therapy of renal cell carcinoma.

The phenotype of peripheral blood lymphocytes of 27 renal cell carcinoma patients before and at the end of subcutaneously given rIL-2 therapy was determined by two colour flow cytometry. Therapy induced changes in peripheral blood leucocyte composition and phenotypes were comparable to those reported for intravenously given rIL-2. The present paper shows a correlation between the 'activation status' of the patient before therapy and eventual response

Early sCD8 plasma levels during subcutaneous rIl-2 therapy in patients with renal cell carcinoma correlate with response.

Plasma sIl-2R and sCD8 levels of 12 patients with renal cell carcinoma were determined before and during subcutaneous rIl-2 therapy. Patients with a complete/partial remission showed a significantly stronger initial increase of sCD8 compared to patients with stable disease or tumour progression

A Systems Approach for Tumor Pharmacokinetics

Recent advances in genome inspired target discovery, small molecule screens, development of biological and nanotechnology have led to the introduction of a myriad of new differently sized agents into the clinic. The differences in small and large molecule delivery are becoming increasingly important in combination therapies as well as the use of drugs that modify the physiology of tumors such as anti-angiogenic treatment. The complexity of targeting has led to the development of mathematical models to facilitate understanding, but unfortunately, these studies are often only applicable to a particular molecule, making pharmacokinetic comparisons difficult. Here we develop and describe a framework for categorizing primary pharmacokinetics of drugs in tumors. For modeling purposes, we define drugs not by their mechanism of action but rather their rate-limiting step of delivery. Our simulations account for variations in perfusion, vascularization, interstitial transport, and non-linear local binding and metabolism. Based on a comparison of the fundamental rates determining uptake, drugs were classified into four categories depending on whether uptake is limited by blood flow, extravasation, interstitial diffusion, or local binding and metabolism. Simulations comparing small molecule versus macromolecular drugs show a sharp difference in distribution, which has implications for multi-drug therapies. The tissue-level distribution differs widely in tumors for small molecules versus macromolecular biologic drugs, and this should be considered in the design of agents and treatments. An example using antibodies in mouse xenografts illustrates the different in vivo behavior. This type of transport analysis can be used to aid in model development, experimental data analysis, and imaging and therapeutic agent design.National Institutes of Health (U.S.) (grant T32 CA079443

Poor induction of interleukin-2 receptor expression on cd8bright+ cells in whole-blood cell-cultures with cd3 mab - implications for immunotherapy with cd3 mab

To induce better stimulation of T cells during recombinant interleukin-2 (rIL-2) therapy of renal cell carcinoma patients, pretreatment with low-dose CD3 monoclonal antibody (mAb) has been proposed. However, in our clinic, such a treatment did not induce additional activation of T cells. To investigate this we performed whole blood cell cultures with rIL-2 or CD3 mAb as a stimulant. Cultures using isolated blood mononuclear cells were used as a control. When stimulated by the addition of rIL-2, the lymphocyte composition and activation of whole blood cultures did not differ from those of mononuclear cell (MNC) cultures. However, when stimulation was performed with CD3 mAb, CD8bright+ cells in whole blood cultures were not or only minimally induced to express CD25 or IL-2 receptor beta (IL-2Rbeta). This is in contrast to the situation found in MNC cultures where all CD8bright+ cells expressed CD25 or IL-2Rbeta to a high extent at the end of culture. When rIL-2 or recombinant interferon gamma (rIFNgamma) was added to whole blood cultures together with CD3 mAb, significantly more CD8bright+ cells were induced to express CD25 or IL-2Rbeta. These results suggest that whole blood cultures represent the in vivo situation better than MNC cultures. In addition, the results suggest that, also in vivo, administration of low-dose CD3 mAb alone might not be sufficient to induce IL-2R expression on CD8bright+ cells, and would therefore not induce additional specific T cell activation in rIL-2-based immunotherapy. The presented results suggest that in vivo simultaneous administration of rIFNgamma or rIL-2 with low-dose CD3 mAb might induce better stimulation of CD8+ T cells than CD3 mAb only

The protective effect of cardiac gene transfer of CuZn-sod in comparison with the cardioprotector monohydroxyethylrutoside against doxorubicin-induced cardiotoxicity in cultured cells

The protective effect of cardiac gene transfer of CuZn-sod in comparison with the cardioprotector monohydroxyethylrutoside against doxorubicin-induced cardiotoxicity in cultured cells. Abou El Hassan MA, Heijn M, Rabelink MJ, van der Vijgh WJ, Bast A, Hoeben RC. Department of Medical Oncology, Free University Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands. [email protected] Doxorubicin-induced cardiotoxicity is related to its production of free radicals that specifically affect heart tissue because of its low antioxidant status. Monohydroxyethylrutoside (monoHER), a potent antioxidant flavonoid, is under development as a protector against doxorubicin-induced cardiotoxicity. The overexpression of high levels of superoxide dismutase (sod) protects against free radical damage in transgenic mice. Seeking alternatives besides the few cardioprotectors that are presently under investigation, the aim of the present study was to investigate the protective effect of cardiac gene transfer of CuZn-sod compared with that of the presently most promising cardioprotector monoHER against doxorubicin-induced cardiotoxic effects on neonatal rat cardiac myocytes (NeRCaMs) in vitro. NeRCaMs were infected with different multiplicity of infections (MOIs) of adenovirus encoding CuZn-sod (AdCuZn-sod). A control infection with an adenovirus vector encoding a nonrelated protein was included. The overexpression of CuZn-sod was characterized within 3 days postinfection. For doxorubicin treatment, NeRCaMs were divided into three groups. The first group was infected with AdCuZn-sod before treatment with doxorubicin (0-50 microM). The second and third groups were treated with doxorubicin (0-50 microM) alone and with 1 mM monoHER, respectively. The LDH release and survival of treated cells were measured 24 and 48 hours after doxorubicin treatment. The beating rate was followed during the 3 days after doxorubicin (0-100 microM) treatment. At the third day after infection with an MOI of 25 plaque-forming unit (PFU) of AdCuZn-sod/cell, the activity of CuZn-sod significantly increased (five-fold, P=.029). Higher MOI produced cytopathic effects (CPEs). Doxorubicin alone produced significant concentration- and time-dependent reduction in NeRCaMs beating rate and survival (P or =50 microM)-treated cells ceased to beat after 24 hours. This cytotoxicity was associated with an increase in the LDH release from the treated cells (P 72 hours in the presence of monoHER.The present study showed the lack of adenoviral CuZn-sod gene-transfer to protect myocardiocytes against doxorubicin-induced toxicity and confirms the efficacy of monoHER cardioprotection. Thus, a gene-therapy strategy involving overexpression of CuZn-sod to protect against doxorubicin-induced cardiotoxicity is not feasible with the currently available adenovirus vectors