Autophagy and the treatment of cancer

 

  • The word ‘autophagy’ is derived from the Greek words “auto” (meaning self) and “phagy” (meaning eating).
  • In a healthy human body, cells are constantly becoming damaged as a normal part of metabolic processes.
  • With increasing age, stress and more free radical damage, our cells become damaged at an increased rate.
  • Autophagy is a normal physiological process that helps to clear damaged cells from the body, including old cells that serve no functional purpose but still linger inside tissues and organs.
  • The reason it’s so important to remove old and damaged cells is because they can trigger inflammatory pathways and contribute to various diseases.
  • Very recently in animal studies, researchers have been able to observe how autophagy can promote longevity and benefit the nervous system, immune system, heart and metabolism.
  • The best way to induce autophagy is through practicing fasting.
  • Autophagy is believed to be a survival mechanism, or a way that the body cleverly responds to stress in order to protect itself.

Mechanism of Autophagy:

  • Thanks to recent studies, we now know that autophagy is important for “cleaning up” the body and defending against the negative effects of stress.
  • The exact way how autophagy processes work is just beginning to be understood.
  • There are several steps involved in autophagy processes.
  • Lysosomes are a part of cells that can destroy large damaged structures, like mitochondria, and then help to transport these damaged parts so they are used to generate fuel.
  • To sum up a complex process: damaged material must first be transported to a lysosome, then deconstructed, then spit back out to be re purposed.
                                                         Mechanism of autophagy

Types of Autophagy:

  • There are several different types of autophagy;
    • Macroautophagy: It is an evolutionarily conserved catabolic process involving the formation of vesicles (autophagosomes) that engulf cellular macromolecules and organelles.
    • Microautophagy: It is the direct uptake of soluble or particulate cellular constituents into lysosomes (in mammals) and in vacuoles (in plants and yeast)
    • Chaperone-mediated autophagy: It refers to the chaperone-dependent selection of soluble cytosolic proteins that are then targeted to lysosomes and directly translocated across the lysosome membrane for degradation.
  • Humans are not the only species to benefit from autophagy. In fact, autophagy has been observed in yeast, mold, plants, worms, flies and mammals.
  • Much of the research to date on autophagy has involved rats and yeast. At least 32 different autophagy-related genes (Atg) have been identified by genetic screening studies.
  • Research continues to show that autophagic processes are very important responses to starvation and stress across many species.
                                                          Types of autophagy

Is autophagy good or bad for our health?

  • It’s definitely good. We might think of autophagy as a form of “self-eating,” which might sound pretty scary but is actually our body’s normal way of carrying out cellular renewal processes.
  • In fact, autophagy is so beneficial that it’s now being called a “key in preventing diseases such as cancer, neurodegeneration, cardiomyopathy, diabetes, liver disease, autoimmune diseases and infections.”
  • Autophagy has many anti-aging benefits because it helps destroy and reuse damaged components occurring in vacuoles (spaces) within cells.
  • In other words, the autophagy process basically works by using breakdown products formed inside cells to create new “building materials” that aid in repair and regeneration.

Benefits of Autophagy:

Research suggests that some of the most important autophagy benefits include:

  • Providing cells with molecular building blocks and energy
  • Recycling damaged proteins, organelles and aggregates
  • Regulating functions of cells’ mitochondria for production of energy and preventing them from oxidative stress.
  • Protecting the nervous system and encouraging growth of brain and nerve cells.
  • Protecting against various heart diseases by supporting the growth of useful heart cells.
  • Enhancing the immune system by eliminating intracellular pathogens
  • Defending against misfolded, toxic proteins that contribute to abnormalities
  • Protecting stability of DNA
  • Preventing damage to healthy tissues and organs (known as necrosis)
  • Potentially fighting cancer, neuro-degenerative disease and other illnesses

Autophagy and the treatment of cancer