Construction of High Sensitive CD133 Immune PLGA Magnetic Spheres Platform for Lung Cancer Stem Cells Isolation and Its Property Evaluation.

High sensitive immune CD133 PLGA magnetic spheres platform is constructed to isolate and enrich lung cancer stem cells in order to study their biological characteristics, such as their proliferation, self-renewal and invasion and metastasis in vitro. The expression of the specific transcription factors Oct 4 and Nanog genes of stem cells were detected by immunofluorescence and RT-PCR. The tumorigenic capacity of lung cancer cells were studied using the tumorigenesis experiment in nude mice in vivo. The results indicated that the CD133 immune PLGA magnetic beads (with diameter 356.25 ± 0.64 nm) can effectively separate more lung cancer stem cells under the serum-free suspension culture compared with MACS CD133 MicroBead Kit. Some A549 cells sorted magnetically could form stable tumor suspended spheres that were able to undergo passage stably after 3 to 6 days. The self-renewal, clonal formation and invasion and metastasis capacities of the suspended spheres were higher than those of the parent cells (P < 0.05). The expressions of Oct 4 and Nanog mRNA in stem cells were significantly elevated (P < 0.05), and the A549 suspended spheres could significantly improve the in vivo tumorigenic capacity of nude mice. Among the peripheral blood of 20 patients with lung adenocarcinoma, CD133+ cells were isolated from the peripheral blood of 14 (70%), and CD133+ cells sorted from 11 (55%) patients were cultured into spheres.