Enhancing the radiosensitivity of colorectal cancer cells by reducing spermine synthase through promoting autophagy and DNA damage

Figure 4 Knockdown of spermine synthase enhances the radiosensitivity of HCT116 cells by promoting autophagy. A and B: Immunofluorescence detection for LC3 puncta in HCT116 cells of the negative control shRNA (shNC) group, shNC + IR group, spermine synthase shRNA (sh-SMS) group, and sh-SMS + IR group; C and D: Western blot analysis for protein levels of LC3-I, LC3-II, p62, and Beclin 1 in HCT116 cells of the shNC group, shNC + IR group, sh-SMS group, and sh-SMS + IR group. ^bP < 0.01 vs shNC, ^dP < 0.01 vs shNC + IR, ^fP < 0.01 vs sh-SMS; SMS: Spermine synthase; sh-SMS: Spermine synthase shRNA; shNC: Negative control shRNA; OE-SMS: Spermine synthase over-expression vector; OE-NC: Negative control over-expression vector.