Figure 1. Reverse transcriptase inhibitor 3TC has preclinical efficacy in colorectal cancer.

A, Schema illustrating experimental procedure for measuring cell migration. B-E, Colon cancer cell line migration data with representative images and quantification of area covered by stained cells in (B, C) P53-Mut and (D, E) P53-WT colon cancer cell lines treated with DMSO or 3TC across 8-μm pore Transwell after 24~72 hr following fixation and staining with crystal violet. Statistical significance calculated by student’s two tailed t-test: * p < 0.05, ** p < 0.01, *** p < 0.001. F-K, Response to 3TC vs DMSO control in soft agar colony assay in (F-H) P53-Mut cell lines SW620 and DLD1 and (I-K) P53-WT cell lines HCT116 and HCT8. (F, I) Representative images of soft agar colonies of SW620 and HCT116 (left) with image quantification markup (right). Scale bar = 2 mm (left), 1 mm (right). Quantification of colony size by digital image analysis shown with violin plot with median and interquartile range in (G-H) P53-Mut cells and (J-K) P53-WT cells treated with DMSO or 3TC at 5 µM and 100 µM. Statistical significance calculated by student’s two tailed t-test: * p < 0.05, ** p < 0.01, *** p < 0.001. L-M, P53-Mut (SW620) and P53-WT (HCT116) CRC xenograft tumors treated with 3TC vs PBS (Control) treatment. Luciferase-expressing (L) SW620 or (M) HCT116 cells were subcutaneously implanted in immunocompromised Nu/Nu mice and grown for 2 weeks after which mice were treated with PBS or 3TC at 50 mg/kg administered by intraperitoneal injection 3 times a week. Tumor luminescence was measured using IVIS imaging every 5 days. Graph represents relative luminescence units (RLU) normalized to Day 0. Significance determined by two-way ANOVA test: **** p < 0.0001.