Original Research
Copyright ©The Author(s) 2001. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 15, 2001; 7(6): 855-859
Published online Dec 15, 2001. doi: 10.3748/wjg.v7.i6.855
Taxotere resistance in SUIT Taxotere resistance in pancreatic carcinoma cell line SUIT 2 and its sublines
Bin Liu, Edgar Staren, Takeshi Iwamura, Hubert Appert, John Howard
Bin Liu, Department of General Surgery, the Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
Edgar Staren, Hubert Appert, John Howard, Department of Surgery, Medical College of Ohio, Toledo, Ohio, USA
Takeshi Iwamura, Department of Surgery, Miyazaki Medical College, Miyazaki, Japan
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Bin Liu, Department of General Surgery, the Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu, China. liubinxy@pub.xz.jsinfo.net
Telephone: +86-516-5802003
Received: April 25, 2001
Revised: June 19, 2001
Accepted: July 1, 2001
Published online: December 15, 2001
Abstract

AIM: To investigate the specific mechanisms of intrinsic and acquired resistance to taxotere (TXT) in pancreatic adenocarcinoma (PAC).

METHODS: MTT assay was used to detect the sensitivity of PAC cell line SUIT-2 and its sublines (S-007, S-013, S-020, S-028 and TXT selected SUIT-2 cell line, S2/TXT) to TXT. Mdr1 (P-gp), multidrug resistance associated protein (MRP), lung resistance protein (LRP) and β-tubulin isotype gene expressions were detected by RT-PCR. The functionality of P-gp and MRP was tested using their specific blocker verapamil (Ver) and indomethacin (IMC), respectively. The transporter activity of P-gp was also confirmed by Rhodamine 123 accumulation assay.

RESULTS: S-020 and S2/TXT were found to be significantly resistant to TXT (19 and 9.5-fold to their parental cell line SUIT-2, respectively). RT-PCR demonstrated strong expression of Mdr1 in these two cell lines, but weaker expression or no expression in other cells lines. MRP and LRP expressions were found in most of these cell lines. The TXT-resistance in S2-020 and S2/TXT could be reversed almost completely by Ver, but not by IMC. Flow cytometry showed that Ver increased the accumulation of Rhodamine-123 in these two cell lines. Compared with S-020 and SUIT-2, the levels of β-tubulin isotype II, III expressio ns in S-2/TXT were increased remarkably.

CONCLUSION: The both intrinsic and acquired TXT-related drug resistance in these PAC cell lines is mainly mediated by P-gp, but had no relationship to MRP and LRP express ions. The increases of β-tubulin isotype II, III might be collateral changes that occur when the SUIT-2 cells are treated with TXT.

Keywords: pancreatic neoplasms/pathology; tumor cells, cultured/drug effects; paclitaxel/analogs & derivatives; paclitxael/pharm acology; drug resistance, multiple; drug resistance, neoplasm