Objective The aim is to sort CD90+ subpopulation cells in human liver cancer cell lines and investigate efficiency of magnetic cell sorting (MACS) on sorting the liver cancer stem cells. Methods ①Expressions of CD90. Immunohistochemical method was used to determine the expressions of CD90 in normal liver tissues in 8 cases, liver cancer and adjacent liver cancer tissues in 58 cases. ②Screened the cell lines. Huh-7, MHCC97-H, Bel-7402, and SMMC-7721 cell lines were divided into blank control group and experimental group (5.5×105 cells per hole, 1 hole), cells of the experimental group were added with 5 μL CD90–PE while cells of the blank control group were treated with 5 μL CD90–PE non fluorescent antibody. Determined the proportion of CD90+ cells in the 2 groups by flow cytometry (FCM). ③MACS. Huh-7 and MHCC97-H cell lines were labeled with magnetic beads respectively and sorted by MACS, 1 mL cell suspensionsorted by magnetic sorting (MS) was collected as CD90– group, and 1 mL PBS after MS wash was collected as CD90+ group, as well as blank control group and experimental group. Determined the proportion of CD90+ cells in 4 groups by FCM. Two times of MACS were performed in Huh-7 cells. ④Serum free culture and serum culture. Huh-7 cells were divided into serum-free culture group and serum culture group (1 hole), and proportions of CD90+ cells were determined by FCM at 1 week after culture. Results ①The positive rate of CD90 was 0 (0/8), 65.5% (38/58), and 20.7% (12/58) in normal liver tissues, liver cancer tissues, and adjacent liver cancer tissues respectively, and the positive rate of CD90 was higher in liver cancer tissues than those of normal liver tissues (χ2=6.78, P<0.05) and adjacent liver cancer tissues (χ2=20.83, P<0.05). ②For Huh-7, MHCC97-H, SMMC-7721, and Bel7402 cell lines, the proportions of CD90+ cells in the experimental group was 0.851%, 1.090%, 2.710%, and 4.050% respectively, the proportions of CD90+ cells in the blank control group was 0.241%, 0.688%, 1.890%, and 2.080% respectively, so we chose Huh-7 and MHCC97-H cell lines to perform MACS. ③Results of MACS for Huh-7 cell line. For the first MACS, the proportions of CD90+ cells in the blank control group, experimental group, CD90– group, and CD90+ group was 0.241%, 0.851%, 0.574%, and 1.100% respectively. For the second MACS, the proportions of CD90+ cells in the blank control group, experimental group, CD90– group, and CD90+ group was 0.032%, 0.961%, 0.426%, and 9.700% respectively. Conclusions The normal liver tissues do not express the CD90, but the liver cancer tissues express CD90 highly. There is a few CD90+ cells in Huh-7 and MHCC97-H liver cancer cell lines. The MACS has a certain effect on improving the proportion of CD90+ cells in the cell lines. The serum-free suspension culture has no effect on enriching CD90+ cells.
ObjectiveTo investigate the most appropriate culture time with the action of EGF in colon cancer stem cells enrichment by suspension culture.MethodsDLD-1 cells were cultured in serum-free medium containing 20 ng/mL EGF to generate spheroid cells. The time gradient was set to 10 d, 20 d, 30 d and 40 d, the cell proportion of CD133+, CD44+ and CD133+CD44+ were confirmed by flow cytometery. The ability of self-renewal was detected by the sphere forming assay and the limited dilution assay, and the in vitro tumorigenicity of the cells was detected by the colony formation assay.ResultsIn the 30 d group, the proportion of CD133+ and CD133+ CD44+ cells were significantly higher than those in the other groups (allP<0.05), the CD44+ cell was higher than that in the 20 d group (P<0.05), but there was no significant difference with the other two groups (P>0.05). The results of the limited dilution assay and the colony formation assay, the number of spheres in the 30 d or 40 d group was the highest among the 4 groups, and there was no statistical difference between the 30 d group and 40 d group (P>0.05), with statistically significant difference between the 30 d, 10 d and 20 d groups (all P<0.05). The results of the sphere forming assay and the self-renewal ability of 30 d group was significantly higher compared with other groups (all P< 0.05).ConclusionThe cancer stem cells could be enriched more efficiently by suspension culture using 20 ng/mL EGF for 30 days.