Figure 4.

The therapeutic effect of knocking down MYST3 in a xenograft tumor model. All animal works have been approved by BCM Institutional Animal Care and Use Committee. 1 × 10⁷ T47D cells Dox dependently expressing shMYST3 were transplanted bilaterally to the mammary fat pad of 4–6 weeks female athymic nude mice (Harlan Sprague–Dawley) supplemented with 17β-estradiol pellets (Sigma-Aldrich). Xenograft tumors of the T47D models are successfully engrafted in 16 mice which were randomized into±doxycycline (Dox) (8 mice per group). Briefly when tumors reached 150 mm³, 0.2 mg/ml Dox was administered in drinking water to turn on shRNA expression. Animals were euthanized after 33 days of treatment and tumors were collected. (a) MYST3 depletion suppresses tumor growth in vivo. The growth of the xenograft tumors was measured three times per week and tumor volume was calculated using the formula 1/2(length × width²). Data are presented as mean±s.d. ***P<0.001. Kaplan–Meier analyses were carried out using the R survival package. P-values were calculated according to the log-rank test. **P<0.01. (b) The protein levels of MYST3 in the collected tumors treated with Dox were decreased. The expression levels of MYST3 and ERα were determined with Western blot. The density of bands was analyzed with ImageJ.