Metformin and cancer: An existing drug for cancer prevention and therapy

Area of Science:

• Oncology
• Pharmacology
• Endocrinology

Background:

• Metformin is a first-line treatment for type 2 diabetes mellitus (T2DM) and polycystic ovary syndrome.
• Epidemiological studies suggest T2DM patients on metformin have reduced cancer incidence and mortality.
• This indicates a potential association between metformin and tumorigenesis, warranting further investigation.

Purpose of the Study:

• To review recent advancements in understanding metformin's role in tumor development.
• To elucidate the mechanisms behind metformin's observed antitumor effects.
• To explore the molecular pathways involved in metformin's anti-cancer properties.

Main Methods:

• Review of in vivo and in vitro studies investigating metformin's effects on tumor cells.
• Analysis of research on signaling pathways potentially mediating metformin's antitumor activity.
• Examination of studies focusing on insulin and insulin-like growth factor signaling.

Main Results:

• Metformin exhibits direct antitumor effects, suppressing tumor cell proliferation.
• It induces apoptosis, autophagy, and cell cycle arrest in tumor cells.
• Potential mechanisms involve the inhibition of phosphoinositide 3-kinase/Akt/mechanistic target of rapamycin (mTOR) signaling via reduced insulin/IGF levels or AMP-activated protein kinase activation.

Conclusions:

• Metformin possesses significant antitumor properties.
• Its anti-cancer effects are likely mediated through complex signaling pathways, including the PI3K/Akt/mTOR pathway.
• Further research is crucial to fully establish the mechanisms and therapeutic potential of metformin in cancer treatment.