Metformin-dependent Immunity can Combat Cancer

Metformin helps in activation of immune cells that keep cancer in check, as per the research led by Okayama University scientists.

Metformin, which is used to treat lifestyle diseases like type 2 diabetes mellitus, have been found to have anti-cancer effects.

Researchers looked at how a specific subset of immune cells, called CD8+ infiltrating T-lymphocytes (CD8TIL), which specifically attack tumor cells, behaved in response to metformin. Their findings have been published as a research article in Journal for ImmunoTherapy of Cancer.

‘Metformin caused CD8TIL to secrete interferon-ɣ to alter the tumor microenvironment to favor death of tumor cells.’
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Prof. Udono, who spearheaded the study, almost gave up on his anti-cancer pursuits, when he lost his own father to cancer. “Nearly 10 years ago, a switch turned on in my head when I attended a Keystone Symposia discussing cancer, and hypoxia, held in Banff, Alberta.

I realized that we had missed addressing Warburg effect, an effect which bolsters the growth of cancer, in our previous research.

So, reverting Warburg effect to normal metabolic profile in cancers became a topic that got me thinking. Surprisingly, I got a hint from the same conference that metformin may aid cancer immunity. So, we got to work!”

Prof. Udono and his team executed experiments on cancer cell lines, and mice genetically “knocked out” for possible biomolecules that result in metformin-dependent anti-tumor immunity.

They probed the intracellular mechanisms in CD8TIL, when exposed to metformin, and assessed different biomarkers for growth. Given that CD8TIL produces proteins called interferons to attack cancer cells, they also assessed corresponding levels.

Metformin was found to cause the generation of reactive oxygen species in the mitochondria of CD8TIL (mtROS) and increases glycolysis. Further, they found that mtROS activated growth pathways in CD8TIL, thus allowing proliferation of these immune cells.

Researchers also ruled out that metformin causes anti-tumor effect through ‘cell suicide’ or apoptosis. Also, they determined that metformin caused CD8TIL to robustly secrete interferon-ɣ to alter the tumor microenvironment to favor death of tumor cells.

Metformin Holds Potential in Treating Brain Tumor
In cell and mouse models, metformin, a commonly used antidiabetic agent, suppressed tumor growth in group A posterior fossa ependymomas.

Speaking about the findings, Prof. Udono exclaims, “More than anything else, our study provides the knowledge that we can ourselves protect our body from cancer.

We hope that this understanding will result in not only the reduction of cancer incidence and improve treatment, but also will help prolong our life.”

The researchers also add that these findings strongly suggest the possibility of using metformin as a drug to strengthen anti-tumor immunity in patients with cancer.

This study bodes well for patients with cancer as well as cancer researchers worldwide.

Source-Medindia