Biologists have destroyed the cancer, forcing him to starve

© Depositphotos / VtanovskiРаковые cellsBiologists have destroyed the cancer, forcing him to starve© Depositphotos / Vtanovski

Scientists from MSU and Sweden successfully suppressed the growth of cancer cells, forcing them to constantly experience the feeling of «hunger» and cease to produce proteins, which do not allow them to self-destruct, according to a paper published in the journal BBA General subjects.

«We know that autophagy can be caused by a partial restriction of nutrients. We were interested in the question — what’s behind it? The mechanism of this phenomenon we studied,» says Boris Zhivotovsky, Professor of biological faculty of Moscow state University.

One of the hallmarks of cancer cells is that they absorb unusual amounts of nutrients and oxygen, using them to their uncontrolled growth and reproduction. In recent years, scientists began to notice that the suppression of the «appetites» of cancer cells facilitates the struggle against them like the immune system, and various types of chemotherapy and immunotherapy.

Zhivotovsky and his colleagues for several years studying how cellular starvation affects the behavior of cancer cells and trying to understand how such effects can be called using a variety of signaling molecules and the various options for gene therapy.

To do this, the researchers grew colonies of two types of «immortal» cancer cells, deprived them of food and followed-up on how to change the activity of different genes related to their division and protection from chemotherapy and immune system. This allowed them to identify several dozen sites of DNA and associated proteins, the activity of which decreased significantly after Zhivotovsky and his team put cancer on a «diet».

The attention of biologists has attracted the protein and its gene Mcl-1, associated with the operation of the system of self-destruction present in all healthy and in many cancer cells. This system, as the scientists explain, consists of dozens of protein molecules, some of which causes the cell to start apoptosis, the process of cell suicide, while others suppress it.

In healthy cells there is a balance between «death proteins» and Mcl-1 and other similar molecules that inhibit their work. When cancer occurs, this balance is shifted towards Mcl-1 and other «proteins of life», so that tumor cells do not die even in case of very serious DNA damage usually causes the cells to kill themselves.

Following this idea, the Russian scientists have created several short RNA molecules, some of which increased the activity of Mcl-1, and others blocked his work. As shown by these experiments, cancer cells and «enhanced» version of the protein better resisted chemotherapy and less were destroyed during the irradiation, a suppression operation associated with the gene, on the contrary, made them extremely vulnerable to their actions.

The same effect, as the researchers note, can be achieved by using various chemical drugs that block the reading of the molecules, which contain «instructions» for the Assembly of molecules Mcl-1. In recent years, scientists have created several substances of this kind, and some of them, for example, the drug ABT-293, have already passed the test of the regulatory authorities in the United States.

As scientists hope that the data gathered by them will help to adapt the substance and its analogues for cancer, while not disturbing the synthesis of Mcl-1 in a healthy cells and resulting in their mass death.