Fig. 1.

Metformin decreases PIN formation in prostrates of Hi-Myc mice. Prostate tissues were dissected from mice that were treated orally with metformin (200 mg/kg/day) from 5 weeks old. Representative hematoxylin and eosin staining of paraffin-embedded prostate tissues at lower magnification (×10) and higher magnification (×40) from vehicle-treated (A) and metformin-treated group (B). (C) Incidence of PIN lesions in dorsal or ventral/lateral lobes of mouse prostates with or without metformin treatment for 4 weeks. (D) Incidence of PCa lesions in ventral/lateral lobes of mouse prostates with or without metformin treatment for 24 weeks. n = 10, *P < 0.05 compare to same lobe in vehicle group by Fisher’s exact test.