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World J Gastroenterol. Feb 14, 2008; 14(6): 925-930
Published online Feb 14, 2008. doi: 10.3748/wjg.14.925
Persistence of side population cells with high drug efflux capacity in pancreatic cancer
Jing Zhou, Chun-You Wang, Tao Liu, Bin Wu, Feng Zhou, Jiong-Xin Xiong, He-Shui Wu, Jing Tao, Gang Zhao, Ming Yang, Shan-Miao Gou
Jing Zhou, Chun-You Wang, Tao Liu, Feng Zhou, Jiong-Xin Xiong, He-Shui Wu, Jing Tao, Gang Zhao, Ming Yang, Shan-Miao Gou, Institute of Pancreatic Surgery, Union Hospital, Huazhong University of Science and Technology, 1277 Jiefang Ave., Wuhan 430022, Hubei Province, China
Bin Wu, Department of Orthopaedics, Union Hospital, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei Province, China
Correspondence to: Chun-You Wang, Institute of Pancreatic Surgery, Union Hospital, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei Province, China. wangchunyou52@126.com
Telephone: +86-27-85351621
Fax: +86-27-85351669
Received: August 28, 2007
Revised: November 16, 2007
Published online: February 14, 2008
Abstract

AIM: To investigate the persistence of side population (SP) cells in pancreatic cancer and their role and mechanism in the drug resistance.

METHODS: The presentation of side population cells in pancreatic cancer cell line PANC-1 and its proportion change when cultured with Gemcitabine, was detected by Hoechst 33342 staining and FACS analysis. The expression of ABCB1 and ABCG2 was detected by real-time PCR in either SP cells or non-SP cells.

RESULTS: SP cells do exist in PANC-1, with a median of 3.3% and a range of 2.1-8.7%. After cultured with Gemcitabine for 3 d, the proportion of SP cells increased significantly (3.8% ± 1.9%, 10.7% ± 3.7%, t = 4.616, P = 0.001 < 0.05). ABCB1 and ABCG2 expressed at higher concentrations in SP as compared with non-SP cells (ABCB1: 1.15 ± 0.72, 5.82 ± 1.16, t = 10.839, P = 0.000 < 0.05; ABCG2: 1.16 ± 0.75, 5.48 ± 0.94, t = 11.305, P = 0.000 < 0.05), which may contribute to the efflux of fluorescent staining and drug resistance.

CONCLUSION: SP cells with inherently high resistance to chemotherapeutic agents do exist in pancreatic cancers, which may be candidate cancer stem cells contributing to the relapse of the tumor.

Keywords: Side population cells; Hoechst 33342; Drug resistance; Cancer stem cells; Pancreatic cancer