Increased intracellular doxorubicin by anti-FAS monoclonal antibody: a mechanism that enhances the cytotoxicity in renal cell carcinoma cells.
OBJECTIVE
To investigate the effect of anti-Fas monoclonal antibody (mAb) on the intracellular concentration of doxorubicin in renal cell carcinoma (RCC) cells. Little is known about the influence of anti-Fas mAb on the intracellular concentration of chemotherapeutic agents.


METHODS
The concentration of intracellular doxorubicin was determined by high-performance liquid chromatography. The mRNA and protein levels of multidrug resistance-associated protein gene were evaluated by reverse transcriptase-polymerase chain reaction and immunocytochemistry, respectively.


RESULTS
An increased concentration of doxorubicin inside the cells was found: 2.4-fold in ACHN cells (a human RCC cell line) after treatment with doxorubicin combined with anti-Fas mAb compared with doxorubicin alone. Of the five cases of freshly derived RCC cells treated with doxorubicin and anti-Fas mAb, the intracellular concentration of doxorubicin was increased 2.3 and 2.7-fold in two of them, respectively. Furthermore, both the mRNA and the protein levels of the multidrug resistance-associated protein gene were downregulated after treatment of ACHN cells with anti-Fas mAb. Treatment of ACHN cells with a combination of anti-Fas mAb and doxorubicin resulted in a potentiation of the doxorubicin-mediated cytotoxicity.


CONCLUSIONS
The increased intracellular concentration of doxorubicin by anti-Fas mAb might be one of the mechanisms responsible for the enhancement of doxorubicin-mediated cytotoxicity in RCC cells.
Wu
X
X
Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Kakehi
Y
Y
Mizutani
Y
Y
Terachi
T
T
Ogawa
O
O
D018528:ATP-Binding Cassette Transporters / Q000187:drug effects / Q000235:genetics; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000627:therapeutic use; D002292:Carcinoma, Renal Cell / Q000737:chemistry / Q000188:drug therapy / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D004317:Doxorubicin / Q000032:analysis / Q000493:pharmacokinetics* / Q000627:therapeutic use; D004347:Drug Interactions; D015870:Gene Expression / Q000187:drug effects; D019450:Genes, MDR / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins / Q000187:drug effects / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000706:statistics & numerical data; D014407:Tumor Cells, Cultured
D018528:ATP-Binding Cassette Transporters; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D004317:Doxorubicin; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; C411023:anti-Fas monoclonal antibody