Fig. 5.

Pharmacological HDAC inhibition reduces cell and tumor growth, but increases cell migration and tumor metastasis from LNs. a HDAC mRNA expression levels from ex vivo 4T1 clones. b Target gene E2F7, E2F8, and RRM2 and EMT marker expression levels after quisinostat treatment. c, d, Transwell migration assay for 4T1 (c) and E0771-LMB (d) TNBC cells. e Intravital imaging of LN tumors of mice implanted with 4T1-mCh/rL cells. f Tumor volumes for LN-micro-injected tumor-bearing mice treated with vehicle or quisinostat (40 mg/kg; twice weekly). g Enumeration of lung micro-metastases in LN-micro-injected tumor-bearing mice after 6 weeks. h Metastasis index of vehicle- and quisinostat-treated mice after normalization to LN tumor size (n = 10 mice/group for f–h). i Enumeration of lung micro-metastases after in vitro-treated vehicle or quisinostat 4T1-mCh/rL cells were injected by the tail vein. j H&E staining of stitched left lungs from tail vein-injected mice. The graph shows the average number of tumors per lung for vehicle- and quisinostat-treated mice. k Representative H&E-stained images of lung lesions from vehicle- and quisinostat-treated mice. The graph shows individual tumor diameter measurements. Statistical significance was measured by unpaired one-sided Student’s t tests, unless otherwise indicated; p values are indicated as *p < 0.05, **p < 0.01, and ***p < 0.001