Downregulation of cystine transporter xc by irinotecan in human head and neck cancer FaDu xenografts.

Background: The purpose of this study was: (1) to document the critical requirement of cystine for growth of human tumor cells in vitro, and (2) to determine the effect of the anticancer agent irinotecan on the cystine transporter x(c)(-) in head and neck FaDu xenografts.

Methods: Cell growth was measured by sulforhodamine B assay. xCT protein, glutathione (GSH) and DNA damage were determined using Western blot, spectrophotometry, and immunohistochemistry, respectively.

Hypoxia-specific drug tirapazamine does not abrogate hypoxic tumor cells in combination therapy with irinotecan and methylselenocysteine in well-differentiated human head and neck squamous cell carcinoma a253 xenografts.

Well-differentiated hypoxic regions in head and neck squamous cell carcinoma like in A253 xenografts are avascular and, therefore, hinder drug delivery leading to drug resistance and tumor regrowth. Methylselenocysteine (MSC, 0.2 mg/mouse per day per oral for 35 days starting 7 days before the first irinotecan (CPT-11)) has been found to increase efficacy of a wide variety of chemotherapeutic agents including CPT-11 (100 mg/kg per week x 4 intravenously).

Potential tumor markers for human gastric cancer: an elevation of glycan:sulfotransferases and a concomitant loss of alpha1,2-fucosyltransferase activities.

Purpose: Several reports indicate a complexity in glycosyltransferase activities which lead to several tumor associated carbohydrate structures in gastric carcinoma. The present study was aimed to identify the carbohydrate associated transferases which exhibit the most marked and consistent change of activity in gastric tumorigenesis.

Methods: We examined the levels of fucosyl, beta-galactosyl-, beta-N-acetylgalactosaminyl, sialyl- and glycan:sulfotransferase activities, which generate the outer ends of oligosaccharide chains in tumorous and adjacent normal gastric tissues of the same patient in ten gastric carcinoma cases by using well defined specific synthetic acceptors utilized in our several earlier published studies as referenced in the text (e.

The mechanism of methylselenocysteine and docetaxel synergistic activity in prostate cancer cells.

The study was designed to evaluate the combination treatment of methylselenocysteine (MSeC) and docetaxel and to delineate the underlying mechanism associated with observed in vitro synergy between MSeC and docetaxel in prostate cancer cells. Cells were treated with different concentrations and schedules (concurrent or sequential) of MSeC and docetaxel alone or in combination. Cell growth/death was assessed with sulforhodamine B assay, trypan blue assay, and time-lapse video.

Effect of amphotericin B and micafungin combination on survival, histopathology, and fungal burden in experimental aspergillosis in the p47phox-/- mouse model of chronic granulomatous disease.

Chronic granulomatous disease (CGD) is an inherited disorder of the NADPH oxidase characterized by recurrent life-threatening bacterial and fungal infections. We characterized the effects of single and combination antifungal therapy on survival, histopathology, and laboratory markers of fungal burden in experimental aspergillosis in the p47phox-/- knockout mouse model of CGD. CGD mice were highly susceptible to intratracheal Aspergillus fumigatus challenge, whereas wild-type mice were resistant.