The aim of the studies was to evaluate the influence of quercetin on etoposide-induced DNA damage in rat bone marrow cells and on changes in the activities of superoxide dismutase (SOD), catalase and antioxidant power in lung tissue (AOP). Quercetin was administrated by gavage at a dose of 135 mg/kg b.w. for three consecutive days, and one hour after the last dose, etoposide was intraperitoneal...

A metabolite formed by incubation of human liver microsomes, etoposide, and UDP-glucuronic acid was identified as etoposide glucuronide by liquid chromatography-tandem mass spectrometry analysis. According to the derivatization with trimethylsilylimidazole (Tri-Sil-Z), it was confirmed that the glucuronic acid is linked to an alcoholic hydroxyl group of etoposide and not to a phenolic group. Am...

Etoposide (VP-16), a topoisomerase II inhibitor, is an effective anticancer drug currently used for the treatment of a wide range of cancers. Excision repair cross-complementary 1 (ERCC1) is a key protein involved in the process of nucleotide excision repair. High level of ERCC1 expression in cancers is associated with resistance to DNA damage-based chemotherapy. In this study, the effects of p...

Purpose: Glioblastoma (GBM) inevitably recurs despite surgery, radiation, and chemotherapy. A subpopulation of tumor cells, GBM stem cells (GSC), has been implicated in this recurrence. The chemotherapeutic agent etoposide is generally reserved for treating recurrent tumors; however, its effectiveness is limited due to acute and cumulative toxicities to normal tissues. We investigate a novel co...

The farnesyltransferase inhibitor tipifarnib exhibits modest activity against acute myelogenous leukemia. To build on these results, we examined the effect of combining tipifarnib with other agents. Tipifarnib inhibited signaling downstream of the farnesylated small G protein Rheb and synergistically enhanced etoposide-induced antiproliferative effects in lymphohematopoietic cell lines and acut...

Tumor hypoxia is a common characteristic of most solid tumors and is correlated with poor prognosis for patients partly because hypoxia promotes resistance to cancer therapy. Hypoxia selects cancer cells that are resistant to apoptosis and allows the onset of mechanisms that promote cancer cells survival including autophagy. Previously, we showed that human hepatoma HepG2 cells were protected u...

Intratumoral hypoxia is associated with resistance to therapy in many human cancers, and preexposure of tumor cells to hypoxia confers multidrug resistance. Whereas most anticancer drugs kill proliferating tumor cells by causing DNA damage, a role for hypoxia in the prevention and/or repair of drug-induced DNA damage has not been clear. Using the alkaline comet assay, we provide direct evidence...

We administered cisplatin and etoposide by peritoneal dialysis to 39 patients with i.p. malignancies in order to investigate the toxicity, pharmacokinetics, and clinical activity of this 2-drug combination. All patients received i.v. sodium thiosulfate concurrently with the i.p. chemotherapy. Myelosuppression, nausea, vomiting, and malaise were the primary toxicities encountered. The maximum to...

a series of 2-amino-4-(nitroalkyl)-4h-chromene-3-carbonitriles were synthesized by an efficient multicomponent reaction in aqueous media using dbu (1,8-diazabicyclo[5.4.0]undec-7-ene) as a catalyst at room temperature. mild condition, environment friendly procedure and excellent yields are the main advantages of this procedure. the cytotoxic activity of target compounds were evaluated against t...