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

Figure 5 Knocking down spermine synthase enhances radiosensitivity of HCT116 cells by suppressing the mammalian target of rapamycin pathway. Western blot analysis for detecting the protein expression levels of mammalian target of rapamycin (mTOR), p-mTOR, S6K1, p-S6K1, S6, and p-S6 in HCT116 cells under the following conditions: Negative control shRNA (ShNC), shNC + IR, spermine synthase shRNA (sh-SMS), and sh-SMS + IR. ^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; mTOR: Mammalian target of rapamycin.