Email updates

Keep up to date with the latest news and content from BMC Cancer and BioMed Central.

Open Access Highly Accessed Research article

GLUT1 gene is a potential hypoxic marker in colorectal cancer patients

Fu-Yen Chung1, Ming-Yii Huang123, Ching-Sheng Yeh789, Hui-Jen Chang789, Tian-Lu Cheng4, Li-Chen Yen1, Jaw-Yuan Wang56* and Shiu-Ru Lin789*

Author Affiliations

1 Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China

2 Department of Radiation Oncology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, Republic of China

3 Department of Radiation Oncology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China

4 Faculty of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China

5 Division of Gastrointestinal and General Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, Republic of China

6 Department of Surgery, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China

7 Bio-medical Technology Developmental Center, Fooyin University, Kaohsiung Hsien, Taiwan, Republic of China

8 Department of Medical Technology, School of Medical and Health Sciences, Fooyin University, Kaohsiung Hsien, Taiwan, Republic of China

9 Department of Medical Research, Fooyin University Hospital, Ping-Tung Hsien, Taiwan, Republic of China

For all author emails, please log on.

BMC Cancer 2009, 9:241  doi:10.1186/1471-2407-9-241

Published: 20 July 2009

Abstract

Background

Tumor hypoxia is an important factor related to tumor resistance to radiotherapy and chemotherapy. This study investigated molecules synthesized in colorectal cancer cells during hypoxia to explore the possibility of developing molecular probes capable of detecting cell death and/or the efficiency of radiotherapy and chemotherapy.

Methods

At first, we incubated two human colorectal adenocarcinoma cell lines SW480 (UICC stage II) and SW620 (UICC stage III) cells in hypoxic (≤2% O2, 93% N2, and 5% CO2) and normoxic conditions (20% O2, 75% N2, and 5% CO2) for 24 h and 48 h. The relative expression ratio of GLUT1 mRNA in hypoxic conditions was analyzed by RT-PCR. Ten cancerous tissues collected from human colorectal cancer patients were examined. HIF-1α and HIF-2α levels were measured to indicate the degree of hypoxia, and gene expression under hypoxic conditions was determined. As a comparison, HIF-1α, HIF-2α, and GLUT1 levels were measured in the peripheral blood of 100 CRC patients.

Results

Hypoxia-induced lactate was found to be elevated 3.24- to 3.36-fold in SW480 cells, and 3.06- to 3.17-fold in SW620 cells. The increased relative expression ratio of GLUT1 mRNA, under hypoxic conditions was higher in SW620 cells (1.39- to 1.72-fold elevation) than in SW480 cells (1.24- to 1.66-fold elevation). HIF-1α and HIF-2α levels were elevated and GLUT1 genes were significantly overexpressed in CRC tissue specimens. The elevated ratio of GLUT1 was higher in stage III and IV CRC tissue specimens than in the stage I and II (2.97–4.73 versus 1.44–2.11). GLUT1 mRNA was also increased in the peripheral blood of stage II and III CRC patients as compared to stage I patients, suggesting that GLUT1 may serve as a hypoxic indicator in CRC patients.

Conclusion

In conclusion, this study demonstrated that GLUT1 has the potential to be employed as a molecular marker to indicate the degree of hypoxia experienced by tumors circulating in the blood of cancer patients.