Figure 4. ER-α36 knockdown reduces the sensitivity of the xenograft tumors of ER-α36-positive breast cancer to pterostilbene.

Mb231/Si36 and Mb231 cells were injected into the left and right breast pad, respectively of 5 to 6 weeks old nude mice. When the tumors reached about 50 mm³ size, the mice were randomly assigned into two groups (n = 3): vehicle control (Veh) and pterostilbene treatment (+Pter). a. Tumor volumes were measured once every two days. Red arrows indicate the timed of pterostilbene administration. b. Tumor weights were calculated and are shown as a plot with the median and whiskers from minimum to maximum. c. The representative images of tumors in each group are shown. d. Paraffin-embedded tissue sections of the above tumors were subjected to H&E staining (X 40, left panels) and immunohistochemical (IHC) staining using the antibody against ER-α36 (X 100, right panels). (**p<0.01, NS: no significance).