Metformin Inhibits the Urea Cycle and Reduces Putrescine Generation in Colorectal Cancer Cell Lines oleh Tao Zhang, Ling Hu, Jia-Feng Tang, Hang Xu, Kuan Tian, Meng-Na Wu, Shi-Ying Huang, Yu-Mei Du, Peng Zhou, Rui-Jin Lu, Shuang He, Jia-Mei Xu, Jian-Jun Si, Jing Li, Di-Long Chen, Jian-Hua Ran