RESUMO
BACKGROUND: Primary liver cancer cells (PLCs) could more directly simulate the human tumor microenvironment. Compared with liver cancer cell lines, PLCs could reflect the human situation. As in previous studies, tumor stem cells were a small number of cancer cells in the microenvironment and considered to be one of the origins of liver cancer. This study aimed to screen stem cells in PLCs, analyze their biological characteristics, propose the possibility that liver cancer originated from stem cells. METHODS: Liver cancer tissues of 17 patients were taken from the Affiliated Hospital of Guangdong Medical College, and PLCs were isolated by tissue slice method. The proliferation, tumor formation in nude mice, stem protein expression of PLCs were observed. C-kit+ liver cancer cells were screened and their biological characteristics were analyzed. RESULTS: PLCs could be stably passaged. Transmission electron microscopy indicated that the nucleus was irregular, there were many mitochondria, and the endoplasmic reticulum was irregularly distributed. PLCs could express E-Cadherin, Oct-4, ß-Catenin, Sox2, CD326, C-kit, GPC3, Nanog. The proliferation curve of PLCs and Hep3B cells were similar, and they all could form tumors in nude mice. Flow-sorted C-kit+ PLCs, as well as C-kit+ Hep3B cells could highly express Bmi1, Sox2, Oct4, Notch1, Nanog, C-kit, ß-Catenin, Smo, Nestin, ABCG2, ABCB1. And they also could clone and form tumors in vivo. But C-kit+ PLCs were more sensitive to chemotherapy drugs than C-kit+ liver cancer cell lines. CONCLUSION: C-kit+ PLCs had the characteristics of tumor stem cells and were more sensitive to chemotherapy drugs.
Assuntos
Neoplasias Hepáticas/patologia , Células-Tronco Neoplásicas/patologia , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos Nus , Células Tumorais CultivadasRESUMO
Accumulating evidence has indicated the importance of cancer stem cells in carcinogenesis. The goal of the present study was to determine the effect of low-dose cisplatin on enriched liver cancer stem cells (LCSCs). Human hepatoblastoma HepG2 cells were treated with concentrations of cisplatin ranging from 1 to 5 μg/mL. Cell survival and proliferation were evaluated using a tetrazolium dye (MTT) assay. LCSCs were identified using specific markers, namely aldehyde dehydrogenase-1 (ALDH1) and CD133. The percentage of ALDH1+ or CD133+ cells was examined by flow cytometric analysis. The expression of ALDH1 and/or CD133 in HepG2 cells was determined by immunocytochemical analysis. Low-dose cisplatin treatment significantly decreased cell survival in HepG2 cells after 24 or 72 h. However, the percentage of LCSCs in the surviving cells was greatly increased. The percentage of ALDH1+ or CD133+ cells was increased in a time- and dose-dependent manner after treatment with 1-4 μg/mL cisplatin, whereas 5 μg/mL cisplatin exposure slightly reduced the number of positive cells. These findings indicate that low-dose cisplatin treatment may efficiently enrich the LCSC population in HepG2 cells.