Selective Cytotoxicity (selective + cytotoxicity)

Distribution by Scientific Domains

Selected Abstracts

Selenium- and Tellurium-Containing Multifunctional Redox Agents as Biochemical Redox Modulators with Selective Cytotoxicity

Dr. Vincent Jamier
Abstract Various human diseases, including different types of cancer, are associated with a disturbed intracellular redox balance and oxidative stress (OS). The past decade has witnessed the emergence of redox-modulating compounds able to utilize such pre-existing disturbances in the redox state of sick cells for therapeutic advantage. Selenium- and tellurium-based agents turn the oxidizing redox environment present in certain cancer cells into a lethal cocktail of reactive species that push these cells over a critical redox threshold and ultimately kill them through apoptosis. This kind of toxicity is highly selective: normal, healthy cells remain largely unaffected, since changes to their naturally low levels of oxidizing species produce little effect. To further improve selectivity, multifunctional sensor/effector agents are now required that recognize the biochemical signature of OS in target cells. The synthesis of such compounds provides interesting challenges for chemistry in the future. [source]

Click Chelators for Platinum-Based Anticancer Drugs

Aurélie Maisonial
Abstract Triazoles from "click chemistry" are convenient ligands for the formation of platinum complexes bearing combined triazole,amine or triazole,carboxylate moieties. Striking differences in the chelation modes are observed between the two series. One of the triazole,amine platinum complexes exhibits selective cytotoxicity against breast cancer cells lines. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Conjugation of methotrexate to immunoglobulins kills macrophages by Fc receptor mediated uptake?

Summary The aim of this study was to conjugate methotrexate (MTX) with intravenous immunoglobulin (IVIG) and investigate whether the conjugate produce selective cytotoxicity on macrophages to provide a new strategy for the management of idiopathic thrombocytopenic purpura. MTX was bound to IVIG via human serum albumin as an intermediary. The binding activity of the Fc fragment of the conjugate was assayed by flow cytometry. The selective cytotoxicity of the conjugate was determined by trypan blue exclusion. After conjugating, the binding activity of the conjugate to Fc receptors did not diminish when compared with IVIG. In vitro, the conjugate showed significantly higher cytotoxicity to macrophages than Hela cells. The conjugate of IVIG and MTX showed potent and selective cytotoxicity to macrophages in vitro. [source]

Novel selective cytotoxicity of wild sarsaparilla rhizome extract

Y. G. Huang
Among six fractions, including total extract and fractions of hexane, ethyl acetate, butanol, water and boiling water extracted and separated from wild sarsaparilla rhizome, the hexane fraction (HRW) was the most effective in eliminating four different human cancer cell lines with cellular viability less than 6.8%. HRW exhibited the highest potency against human leukaemia cells with an IC50 (concentration that inhibited the growth rate of cells by 50%) of 3.3 ± 0.3 ,g mL,1, which was 17.6-fold smaller than that against normal human umbilical vein endothelial cells (IC50, 58.0 ± 1.5 ,g mL,1). For its rich natural resources, simple extraction procedure and high yield (3.2%), HRW has the potential to be developed as a selective anti-cancer nutraceutical or pharmaceutical natural health product with low side effects and high economical return. [source]

Chemistry, biological activity, and chemotherapeutic potential of betulinic acid for the prevention and treatment of cancer and HIV infection

Robert H. Cichewicz
Abstract 3,-Hydroxy-lup-20(29)-en-28-oic acid (betulinic acid) is a pentacyclic lupane-type triterpene that is widely distributed throughout the plant kingdom. A variety of biological activities have been ascribed to betulinic acid including anti-inflammatory and in vitro antimalarial effects. However, betulinic acid is most highly regarded for its anti-HIV-1 activity and specific cytotoxicity against a variety of tumor cell lines. Interest in developing even more potent anti-HIV agents based on betulinic acid has led to the discovery of a host of highly active derivatives exhibiting greater potencies and better therapeutic indices than some current clinical anti-HIV agents. While its mechanism of action has not been fully determined, it has been shown that some betulinic acid analogs disrupt viral fusion to the cell in a post-binding step through interaction with the viral glycoprotein gp41 whereas others disrupt assembly and budding of the HIV-1 virus. With regard to its anticancer properties, betulinic acid was previously reported to exhibit selective cytotoxicity against several melanoma-derived cell lines. However, more recent work has demonstrated that betulinic acid is cytotoxic against other non-melanoma (neuroectodermal and malignant brain tumor) human tumor varieties. Betulinic acid appears to function by means of inducing apoptosis in cells irrespective of their p53 status. Because of its selective cytotoxicity against tumor cells and favorable therapeutic index, even at doses up to 500 mg/kg body weight, betulinic acid is a very promising new chemotherapeutic agent for the treatment of HIV infection and cancer. © 2003 Wiley Periodicals, Inc. Med Res Rev, 24, No. 1, 90,114, 2004 [source]

Tumor hypoxia: A target for selective cancer therapy

CANCER SCIENCE, Issue 12 2003
Shinae Kizaka-Kondoh
Tumor hypoxia has been considered to be a potential therapeutic problem because it renders solid tumors more resistant to sparsely ionizing radiation (IR) and chemotherapeutic drugs. Moreover, recent laboratory and clinical data have shown that tumor hypoxia is also associated with a more malignant phenotype and poor survival in patients suffering from various solid tumors. Therefore, selective targeting of hypoxic tumor cells has been explored, and since severe hypoxia (pO2<0.33%, 2.5 mmHg) does not occur in normal tissue, tumor hypoxia could be exploited for therapeutic advantage. However, the following three characteristics of hypoxic tumor regions present obstacles in targeting hypoxic cells. First, it is difficult to deliver a sufficient amount of drug to a region that is remote from blood vessels. Second, one must specifically target hypoxic tumor cells while sparing normal well-oxygenated tissue from damage. Finally, the severely hypoxic tumor cells to be attacked have often stopped dividing. Therefore, high delivery efficiency, high specificity and selective cytotoxicity are all necessary to target and combat hypoxic tumor cells. The current review describes progress on the biological aspects of tumor hypoxia and provides a compilation of the recent molecular approaches used to target hypoxic tumors. These approaches include our work with a unique hypoxia-targeting protein drug, TOP3, with which we have sought to address the above three difficulties. [source]