Secrets of Your Cells: Discovering Your Body's Inner Intelligence (25 page)

Genetic Expression and Stem Cells

Every cell in your body has the same genes, and all have the same genetic potential. What distinguishes cells is which genes and proteins get expressed. Stem cells can use all the genetic information we possess and have the potential to become any cell type; the molecular environment these cells are placed in will determine whether the stem cells become blood cells or kidney cells, heart or bone. Once a cell becomes specialized or differentiated, however, it usually loses its ability to develop into other cell types. After the “purpose” of a cell is determined, it will express only
features of that particular cell type. Immature red blood cells in the bone marrow can only develop into mature red blood cells. They can’t revert back to stem cells and become white blood cells. Only immature red blood cells can make the protein hemoglobin. Dedicated skin cells, even though they have the necessary genetic information to do so, can’t produce hemoglobin. Kidney cells express different proteins and functions from heart cells, even though both contain identical genetic instructions. Each normal cell has “brakes”: controls that allow certain messages or codes to be opened and translated while others are set aside and ignored. In other words, each cell is able to prevent certain genetic messages from being expressed. Even in the small sampling of examples I just provided, you can begin to see the complexity of the strict rules DNA lays down to create our intricately crafted bodies.

Figure 6.4
The eight trigrams that are part of the
I Ching
. The solid line represents yang, the creative principle. The broken line represents yin, the receptive principle. Each trigram represents different qualities. Two trigrams make up a hexagram.

What tells the cell to turn off a message or express it? This question makes for some of the most exciting research to date. An emerging concept called
epigenetics
indicates that
the environment
can modify gene expression.
⁸
Epigenetics shows that though the genetic code itself may not be altered, what those genes do can be influenced by the diet, drugs, and even lifestyle. Dr. Dean Ornish explored this idea in men with prostate cancer. Those men who stuck to specific lifestyle habits for three months, including a vegetarian diet, stress reduction, and social support, showed significant changes in prostate cancer genes. The
expression
of the cancer genes was lowered significantly.

Numerous studies in animals reveal that external influences affect what genes will do, and the changes in genetic expression can be passed on to subsequent generations. What a mother eats during pregnancy can affect how the genes are expressed in her offspring. This was first demonstrated in the now famous agouti mice experiments done by researchers Randy Jirtle and Robert Waterland at Duke University.
⁹
Agouti mice are obese yellow rodents that have these characteristics because of the presence of a particular gene—the agouti gene. When they breed, their offspring not only share these characteristics but are also prone to cancer and diabetes. When the researchers changed the potential mouse moms’ diet just prior to conception, their offspring, though carrying the agouti gene, were healthy and lean brown critters. The specifics of the diet ensured that the mother mouse got lots of simple, regulating molecules found in such foods as garlic, onions, and beets. The DNA regulating molecules, called
methyl donors,
include choline, methionine, and folic acid and are available in our food and supplements. For decades, pregnant women have been encouraged to take adequate folate to ensure healthy brain development in their babies.

Epigenetics research is exciting because it provides evidence for an entirely new understanding: we are not necessarily defined by our genes. Devastating genetic illnesses may not have to be passed on to our children if we can learn how to effect the change. Genes are not immutable,
or fixed in stone; on the contrary, their expression is actively open to change. Genes are not pulling the strings of our life—instead, we and the strings of our cytoskeleton are pulling them! Essentially, the field of epigenetics shows that the actual structure of the gene or its code is not changed; only its expression is altered.

Pioneering scientist Bruce Lipton tells us that our beliefs and attitudes can also change our genes, as might imagery and other healing practices.
¹⁰
Knowing that it’s possible to alter our genetic fate may contribute to our ability to do so.

EXPLORATION

Body Prayer: Unwinding Our DNA

You will recognize similar practices from
chapters 2
and
5
. This time, reflecting on DNA, we emphasize the spiral nature of the movement. Stand facing something you find beautiful, or close your eyes. Feel your feet firmly on the ground, with the soles of your feet in full contact with the earth. Your head is upright and your spine is straight. Place your tongue on the roof of your mouth behind your teeth; this is the “inner smile.”

Now begin moving in a spiral by inscribing a circle with your waist, moving clockwise for a few minutes and then counterclockwise. You might even feel your back getting involved in the movement. Breathe easily and see whether you want to spiral more in one direction than the other. You do not need to count your circles; just tune in to the movement. Humming the sound “mmm” while spiraling may be just the key to soothing your cells, your self. As you move and hum, you can also imagine that this easy, stress-reducing, energy-generating practice is correcting any errors in your DNA. When you feel grounded, stop. Feel your feet still in full contact with the earth. Feel yourself rooted in the earth and connected to the sky. Clasp your hands to your belly and give thanks.

You may want to experiment with doing this basic qigong posture in spare moments throughout the day. It builds a bridge that connects the earth, your cells, and the heavens.

Making and Repairing Mistakes

Each day about a hundred billion cells in the human body divide, making new cells. Recall what happens to the DNA as a cell divides—the paired strands of DNA separate, unwind, and then are copied, letter by letter, serving as the template for an identical partner to be created. While this is happening, a mistake can be made by mismatching the triplets, omitting or adding in a wrong letter; such a mistake is a
mutation.
A mutation of a single code letter can change which amino acid is placed in the scripted protein. Even one change can alter the shape and function of the protein being produced—an incorrect code can make the protein stiffer or too flexible or a totally different shape from the original. The protein may no longer work the way it is supposed to. Since even a single, minuscule error such as this can affect the health of the cell, a potent repair mechanism must be available to protect the cell from damage. In fact, in nature’s wisdom, multiple repair systems are present in our cells.

At the genesis of this growth of cells, self-correction is insured by the wavy strands of molecular intelligence held tight unwinding and letting go only after perfection is created.

— CHRISTOPHER VAUGHAN
How Life Begins

Much of the time, our cells get it right, yet sometimes they don’t. In fact, it’s been estimated that at least a thousand errors are committed inside our cells every day. Fortunately, the cell possesses innate wisdom, built into the architecture of the DNA helix, that recognizes when an error has been made. Damage or errors in DNA trigger an astonishing sequence of events as a gene called p53 rides to the rescue.

The p53 system is both a “spell-checker” and an emergency brake on cell growth, and it has other genes under its command. If an error is created, the p53 gene orders other genes to stop being copied until repairs can be made to the DNA. Once the damaged DNA is repaired, p53 turns on the green light and allows the cell reproduction cycle to continue. But what if the damage is beyond repair? In that case, p53
activate genes that direct the cell to self-destruct; this is known as
programmed cell death
or
apoptosis,
which comes from the Latin for “falling leaves.”
¹¹
Apoptosis, in contrast to traumatic or necrotic cytotoxic death, is a relatively gentle process in which parts of the cell slough off and are recycled or removed by the scavenger cells—falling leaves are an apt metaphor, with their ability to decompose, be recycled into the earth, and even nourish the tree that once sustained them.

A traumatic or cytotoxic death, by contrast, is one in which the cell is acutely damaged and basically explodes, releasing its contents into the cellular environment. This type of cell death can damage the surrounding tissues as it sets free potentially dangerous substances from the cell. Cells contain numerous substances that, if released, can harm other molecules; however, within the cell they are compartmentalized to protect against their damaging effects. Apoptosis is a slower process that allows the neighborhood to reclaim or eliminate cell parts, one step at a time, without damaging the area.

To sum up the role of p53, it’s the damage-control specialist with the capability to correct gene errors, prevent amplification of unruly DNA, suppress tumor cell growth, and when necessary, push cells into programmed self-elimination. Our cells have other numerous backup systems as well to ensure healthy survival.

Death, a Natural Process

Normal cells do not live forever. Death is an ordinary and necessary function of our cells. And the programmed cell death just described is not limited to a last-ditch cure for DNA mistakes. Apoptosis (you could call it assisted suicide) actually ensures normal development.
¹²
In our fetal phase of life, for example, during the “fin stage” when we have not yet developed hands, programmed cell death eliminates unnecessary cells in the area, and voilà!—fingers are formed. Apoptosis also eliminates any renegade immune cells in our thymus that could mistakenly attack our self cells. Brain cells that don’t connect with others are also
programmed to die. Cells that are irreparably damaged are expected to commit “hara-kiri” for the good of the cellular community. So within each cell, there must be knowledge it has to die. A characteristic of the abnormal cancer cell is that it has
forgotten to die.

Taking a moment to reflect further on the normal, continual, gentle dying process of our cells, we find the genetic reminder that the dying process is a natural part of life; it is not a mistake or a failure.

Cells have multiple strategies to ensure elimination of unhealthy cells—p53 genes are not the only ones in charge. A strip at the tip of our chromosomes also regulates when a cell will die (see
figure 6.2
). Called telomeres, a repetitive DNA sequence (such as TTAGGG) akin to a string of pearls, these are a kind of molecular clock that ensures mortality.
¹³
Each time a cell divides, it loses some “pearls,” which shortens the chromosome. At birth, the length of the telomeres in human white blood cells is about eight thousand nucleotide units long. In the elderly there may only be fifteen hundred units left in a cell. Typically, a normal cell can divide about fifty to seventy times, with the telomeres shortening each time. Eventually, the strip of telomeres becomes so short that the cell fails its internal checkup and is identified as a damaged or senescent cell. Finally, in cellular “old age,” it is ready to be eliminated. It stops dividing and dies a quiet death.