Functional evaluation of multidrug resistance transporter activity in surgical samples of solid tumors.

Abstract

Determination of multidrug resistance (MDR) activity of tumor cells could provide important information for the personalized therapy of cancer patients. The functional calcein assay (MultiDrug Quant Assay, Solvo Biotechnology, Budaörs, Hungary) has been proven to be clinically valuable in hematological malignancies by determining the transporter activity of MDR protein 1 (MDR1, ATP-binding cassette protein [ABC] B1, P-glycoprotein-170) and MDR-related protein 1 (MRP1, ABCC1). In this study, we evaluated if the same functional test was adaptable for the analysis of MDR activity in solid tumors. For this purpose, tissue specimens of human colorectal cancer samples were subjected to limited enzymatic digestion by collagenase to provide a single-cell suspension; dead cells were excluded by 7-aminoactinomycin D staining, and epithelial cancer cells were detected by Cy5-conjugated anti-BerEP4 monoclonal antibody. The transporter functions of MDR1 and MRP1 in viable epithelial cells were assessed by flow cytometry detecting the intracellular accumulation of calcein dye after exposing cells to various MDR inhibitors. Collagenase disintegration preserved the MDR activity and the antigenicity of tumor cells. Thus using the extended calcein assay provided sufficient viable and functionally active tumor cells from surgical biopsies to determine the functional MDR activity. In conclusion, the newly described modified calcein assay may be applicable for evaluating the MDR phenotype in solid tissue specimens from colorectal forceps biopsy to surgical samples.

• Authors: Richard Schwab, Tamás Micsik, Orsolya Szokolóczi, Eszter Schafer, Balázs Tihanyi, Tibor Tihanyi, Péter Kupcsulik, Katalin Diófalvi, Tamás Mersich, Istvan Besznyak Jr, Attila Zarand, Rudolf Mihalik, Balázs Sarkadi, György Kéri, Akos Pap, Ferenc Jakab, László Kopper, Istvan Petak
• Journal: Assay and drug development technologies (Assay Drug Dev Technol) Vol. 5 Issue 4 Pg. 541-50 (Aug 2007) ISSN: 1540-658X [Print] United States
• PMID: 17767422 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• ATP Binding Cassette Transporter, Subfamily B, Member 1
• Antibodies, Monoclonal
• Antigens, Neoplasm
• Antigens, Surface
• Biomarkers
• Fluoresceins
• Keratins
• fluorexon

Topics

• ATP Binding Cassette Transporter, Subfamily B, Member 1 (analysis)
• Animals
• Antibodies, Monoclonal (chemistry)
• Antigens, Neoplasm (analysis)
• Antigens, Surface (analysis)
• Biomarkers (analysis)
• Biopsy
• Body Fluids (chemistry)
• Carcinoma (chemistry)
• Cell Separation
• Cell Survival
• Fluoresceins (analysis)
• Fluorescent Antibody Technique
• Humans
• Keratins (analysis)
• Leukemia P388 (metabolism)
• Neoplasms (chemistry, surgery)