Crosstalk-eliminated Quantitative Determination of Aflatoxin B1-induced Hepatocellular Cancer Stem Cells Based on Concurrent Monitoring of CD133, CD44, and Aldehyde Dehydrogenase1

Abstract

Cancer stem cells (CSCs), known as tumor initiating cells, have become a critically important issue for cancer therapy. The properties of CSCs, such as anticancer drug and radiation resistance, have been considered to be the source of postoperative recurrence and metastasis. In this work, it was found that hepatocellular CSCs were produced from HepG2 cells by aflatoxin B1-induced mutation, and their amount was quantitatively determined using crosstalk-eliminated multicolor cellular imaging based on quantum dot (Qdot) nanoprobes and an acousto-optical tunable filter (AOTF). Although much research has demonstrated the induction of hepatocellular cancer by aflatoxin B1 found in contaminated foods and the interrelation between them, the formation of hepatocellular CSCs caused by aflatoxin B1 and their quantitative determination are hardly reported. Hepatocelluar CSCs were acquired from HepG2 cells via magnetic bead-based sorting and observed using concurrent detection of three different markers: CD133, CD44, and aldehyde dehydrogenase1 (ALDH1). The DNA mutation of HepG2 cells caused by aflatoxin B1 was quantitatively observed via absorbance spectra of aflatoxin B1-8,9-epoxide-DNA adducts. The percentages of hepatocellular CSCs formed in the entire HepG2 cells were determined to be 9.77±0.65%, 10.9±1.39%, 11.4±1.32%, and 12.8±0.7%, respectively, at 0 μM, 5 μM, 10 μM, and 20 μM aflatoxin B1. The results matched well with those obtained utilizing flow cytometry, which is used as a general tool for the detection of hepatocellular CSCs. This study demonstrates that accurate quantitative measurement of aflatoxin B1-induced hepatocellular CSCs can be accomplished using a constructed multicolor cellular imaging system that eliminates crosstalk among hepatocellular CSC biomarkers.