DNA methyltransferase 1/miR-342-3p/Forkhead box M1 signaling axis promotes self-renewal in cervical cancer stem-like cells in vitro and nude mice models

Figure 4 Effect of DNA methyltransferase 1 shRNA on cervical cancer stem cell-like cell characteristics in HeLa-derived cervical cancer stem cell-like cells. A: DNA methyltransferase 1 (DNMT1) mRNA level in cervical cancer stem cell-like cells (CCSLCs) transfected with DNMT1 shRNA; B: MicroRNA (miR)-342-3p levels in CCSLCs transfected with DNMT1 shRNA; C: MiR-342-3p promoter methylation in CCSLCs transfected with DNMT1 shRNA; D: Forkhead box M1 (FoxM1) protein amounts in CCSLCs transfected with DNMT1 shRNA, with α-tubulin as a loading control; E and F: Representative images of spheres (E) and colonies (F) (left) (scale bars = 100 μm). Sphere formation efficiency and colony formation efficiency in CCSLCs transfected with DNMT1 shRNA (right); G: CD133 and CD49f protein amount in CCSLCs transfected with DNMT1 shRNA, with α-tubulin as a loading control; H: SRY-box transcription factor 2 (SOX2) and octamer-binding transcription factor 4 (OCT4) mRNA amounts in CCSLCs transfected with DNMT1 shRNA; I: Subcutaneous xenografts of CCSLCs (1 × 10⁵) treated with sh-negative control (sh-NC) or sh-DNMT1 (left); the comparison of tumor volume (middle left), tumor weight (middle right), and growth curves of tumor xenografts (right) between CCSLCs treated with sh-NC and sh-DNMT1; J: Micrographs of hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) to detect the expression of DNMT1, FoxM1, and CD133 proteins as well as in situ immunofluorescence hybridization for miR-342-3p (scale bars = 50 μm). Data were obtained from xenografts with four mice per group. ^aP < 0.05 vs CCSLCs transfected with sh-NC (n = 4); ^bP < 0.001 vs CCSLCs treated with sh-NC. M: Methylated; U: Unmethylated.