calcein-am has been researched along with Carcinoma* in 2 studies
2 other study(ies) available for calcein-am and Carcinoma
| Article | Year |
|---|---|
Activity of drug efflux transporters in tumor cells under hypoxic conditions.
Tumor cells exhibit mechanisms by which chemotherapeutic drugs can be actively pumped out of the cell (e.g., p-glycoprotein pGP, MRP1), resulting in a multidrug resistant phenotype. Many human tumors show pronounced hypoxia which can result in a local ATP depletion which in turn may compromise the efficacy of these transporters. The aim of this study was therefore to assess the transport activity and expression of drug transporters under hypoxic conditions. Prostate carcinoma cells (R3327-AT1) were exposed to hypoxia (pO2 < 0.5 mmHg) for up to 24h and pump activity was determined by an efflux assay. The results showed that exposing cells to hypoxia for 3-6 h led to a moderate increase in pGP activity. After 24 h pGP activity was reduced by 44% compared to control levels. Hypoxia reduced the MRPI activity to a lesser extent (by 25%). However, the expression of pGP and MRP1 was almost independent of the medium pO2. In conclusion, pronounced hypoxia had only minor effects on the activity of drug transporters with the activity decreasing only after 12-24 h under hypoxia, possibly as a result of ATP depletion. Instead, indirect effects of hypoxia leading to extracellular acidosis seem to have a much more pronounced effect on pGP activity. Topics: Acidosis; Animals; ATP Binding Cassette Transporter, Subfamily B, Member 1; Biological Transport; Carcinoma; Cell Hypoxia; Cell Line, Tumor; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Fluoresceins; Fluorescent Dyes; Isotonic Solutions; Male; Multidrug Resistance-Associated Proteins; Prostatic Neoplasms; Rats; Rhodamine 123; Ringer's Solution; Time Factors; Verapamil | 2008 |
PK11195, an isoquinoline carboxamide ligand of the mitochondrial benzodiazepine receptor, increased drug uptake and facilitated drug-induced apoptosis in human multidrug-resistant leukemia cells in vitro.
The isoquinoline peripheral benzodiazepine receptor ligand PK11195 increased drug (daunomycin)- and fluorochrome (calcein-AM) uptake and induced apoptosis detected by flow cytometry (FCM) technique, DNA electrophoretic analysis and poly(ADP-ribose) polymerase (PARP) cleavage in human multidrug-resistant myeloid leukemia (BL-60/VCR) and ovarian carcinoma (A2780/ADR) cells in vitro. The position of PK11195 with respect to drug-resistance modulator (DRM) efficiency, compared to the reference DRMs with the aid of FCM technique, was as follows: PSC833 > verapamil > PK11195 > vincristine. Our data show up to now not indicated observation that PK11195 possesses multidrug resistance modulating activity. Topics: Antineoplastic Agents; Apoptosis; ATP Binding Cassette Transporter, Subfamily B, Member 1; Biological Transport; Carcinoma; Daunorubicin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Drug Synergism; Female; Fluoresceins; Fluorescent Dyes; HL-60 Cells; Humans; Isoquinolines; Leukemia, Myeloid; Ligands; Mitochondrial Proteins; Ovarian Neoplasms; Receptors, GABA-A; Tumor Cells, Cultured | 2002 |