We have established an Adriamycin (ADM) -resistant small cell lung cancer (SCLC) cell line, SBC-3/ADM100, which shows multifactorial mechanisms of resistance to ADM, such as overexpression of P-glycoprotein, an enhanced detoxifying system and a decrease in topoisomerase II activity. In the present study, we confirmed that SBC-3/ADM 100 showed collateral sensitivity to methotrexate and TNP-351, a new antifolate, though this cell line showed a typical multidrug resistance (MDR) pattern. We also demonstrated a faster uptake and higher accumulation (1.3-fold) of TNP-351 in the SBC-3/ADM100 cells than those in the parent SBC-3 cells. These results explain one of the mechanisms for collateral sensitivity in the resistant cells. Furthermore, this cell line was found to have no cross-resistance to edatrexate and minimal cross-resistance to trimetrexate, 254-S (cisplatin analog), 5-fluorouracil and 4-hydroperoxyifosfamide. These drugs will have clinical importance in patients with SCLC who were previously treated with an ADM-containing regimen. Thus, antifolates, especially TNP-351 and edatrexate, can be expected to eradicate residual multidrug resistant SCLC cells selected by ADM.
|Number of pages||7|
|Journal||Acta medica Okayama|
|Publication status||Published - Jun 1 1997|
- Adriamycin-resistant cell line
- Small cell lung cancer
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)