Metformin and Malignant Tumors: Not Over the Hill

Abstract

Malignant tumors are a major cause of death, and their incidence is increasing worldwide. Although the survival rate for some cancers has improved, treatments for other malignant tumors are limited, and their mortality rate continues to increase. People with type 2 diabetes have a higher risk of malignant tumors and a higher mortality rate than those without diabetes. Metformin is a commonly used hypoglycemic drug. In recent years, a growing number of studies have indicated that metformin has antitumor effects and increases the sensitivity of malignant tumors to chemotherapy. However, the effect of metformin on different tumors is currently controversial, and the mechanism of metformin's antitumor action is not fully understood. Insights into the effect of metformin on malignant tumors and the possible mechanism may contribute to the development of antitumor drugs.

Keywords: 5’ adenosine monophosphate-activated protein kinase; antitumor; insulin resistance; malignant tumor; metformin; type 2 diabetes mellitus.

Figure 1

The indirect anticancer effects of metformin include improving glucose and lipid metabolism, inhibiting tumor-associated inflammation and regulating the tumor microenvironment.

Figure 2

Metformin inhibits cancer by suppressing lipid metabolism.

Figure 3

The direct anticancer effects of metformin. Metformin inhibits cancer by activating AMPK and p53 and inhibitingmTORC, cyclin D1, ROS-JNK/c-Jun and TGFR-β2.