Scientists say cancer cells have an Achilles heel, they can be starved to death

Cancer cells, often viewed as aggressive and robust, are for the first time being seen carrying a biological weakness.

Unlike normal cells, malignant or cancer cells are incapable of having a healthy metabolism and often look for substitute fuels and less efficient metabolic pathways to thrive. 

This has pushed scientists to tailor dietary treatments which could starve cancer cells of all the substrates which could be a potential fuel for them to grow and spread.

Cancer cells are found to be primarily dependent on two substances for survival: glucose (blood sugar) and glutamine (amino acids, a building block of protein). 

Always looking for metabolic shortcuts

While cancer has always existed, the manner in which it destabilizes the healthy cells is still being understood.

Unlike the traditional theories, cancer is now being viewed as a metabolic disease as opposed to being caused by genetic and environmental forces alone.

Thomas Seyfried’s Metabolic Theory of Cancer is enabling researchers to see cancer from the eyes of cellular science.

The old Warburg Theory and Seyfried’s findings suggest that there is a connection between cancer and food metabolism.

It finds a weakness in the cancer cells and how they derive energy to survive.

The theory postulates that cancer cells, though robust, lose their ability to use oxygen for energy production and look for metabolic shortcuts to thrive, such as fermentation (oxidising food without oxygen and generating lesser energy output).

Common substrates they depend on to generate ATP (unit of energy) are: glucose and glutamine.

As per experts, this metabolic instability might be true for all cancer types and can provide opportunity to develop a highly focused, diet-focused approach to treatment.

Mitochondria calls the shot

Some unconventional findings in cancer have suggested that a cell’s mitochondria helps in its progression as opposed to the anticipated nucleus of a cell.

The nucleus is the center of the cell that houses most of the genetic material and mitochondria is primarily the kitchen of the cell, using oxygen to oxidise food and generate energy.

The researchers found that when a nucleus of a cancer cell is made to enter a healthy cell, they continue to replicate or reproduce healthy cells.

However, when a healthy nucleus is made to enter a cell where mitochondria is fermenting glucose or glutamine and is not using oxygen to do the same, the new cell either dies or produces a cancerous offspring.

In fact, these malfunctioning mitochondria are capable of spreading this metabolic dysfunction to surrounding cells and tissues, causing the cancer to spread.

Biotin too has a role to play

A new study has found out that if the supply of Vitamin B7 or biotin is cut off in cancer cells, they can lose their metabolic escape plan.

Published in the journal Molecular Cell, the study found that cancer cells are addicted to glutamine which provides them with essential components like protein and DNA.

A mitochondrial enzyme called pyruvate carboxylase can help cancer cells to grow even when glutamine is not sufficient or is scarce. The functioning of this enzyme is highly dependent on biotin or Vitamin B7.

The research found if cancer cells are deprived of biotin, this can stunt their growth.

However, it also highlighted the high adaptability of cancer cells which switch to alternative metabolic pathways when one source of energy is blocked.