Increased expressions of cellular ATP-binding cassette transporters may be a promising diagnostic marker for colorectal cancer

Abstract

Objectives: To measure the blood expression levels of related drug-resistant ATP-binding cassette (ABC) transporters in colorectal cancer (CRC) patients and to assess these examined transporters for whether they present signi cant expression in connection with the tumor appearance of CRC.

Methods: In this case-control study, the messenger ribonucleic acids were isolated from the blood of 62 CRC patients who were recruited from King Abdulaziz University Hospital Oncology Clinic and 46 controls from King Fahad General Hospital Blood Bank (Jeddah, Saudi Arabia) from September 2016 to March 2017. The Biomedical Ethics Unit at King Abdulaziz University, Jeddah, Saudi Arabia approved this study. The expressions of ABC transporters were measured using quantitative polymerase chain reaction. GraphPad Prism 5 and REST 2009 Software were used to correlate the expressions with clinicopathological independent stages and body mass index. A p-value of less than 0.05 was considered significant.

Results: The results showed that the 3 ABC transporters, particularly ABCC1 (p less than 0.0001), were highly expressed in the blood of CRC patients compared with controls. However, none of the 3 transporters was related to the progression of CRC, age, gender, or body mass index.

Conclusion: The expressions of ABC transporters were found to be significantly higher in CRC patients, and they may act as diagnostic markers and should potentially be tested for their contribution to drug sensitivity in CRC patients.

Figure 1

Expression levels of mRNA for ABC transporters. The expression levels of each ABC transporter were determined using qPCR technique. Their expressions were normalized to the expression of GAPDH housekeeping gene using REST 2009 software. Then, the normalized results were compared using an unpaired t-test with Welch’s correction to calculate the degree of differences in expression between two independent groups. Regarding the mRNA expression levels of ABCB1, ABCC1, and ABCG2 transporters in the blood of CRC patients, the results showed a significant difference in the expression levels of the three ABC transporters (these were higher in CRC patients compared with healthy controls). P values were as follows: *p<0.05; ***p<0.0001.