Genetics and cancer

The human body consists of billions of interdependent cells operating under the orders of a specific tissue cell cycle that allows them to develop, grow, differentiate and die.

Each of these stages is highly controlled by a series of genes that are turned on (activated) and turned off (deactivated) according to the needs of the moment.

To do this, cells receive specific biochemical signals from various internal and external stimuli, telling them what to do at all times.

Any failure or disruption that may occur in any of these stages, will lead to an unbalance.

And this initial unbalance can induce a subsequent cascade of events that are necessary to produce cancer.

Signals may have different origins, from establishing  direct contact with neighboring cells, from exposure to steroid hormones and polypeptides,  from their  internal programs telling them how many times they can divide, from environmental factors related to lifestyle of the individual in question, such as the type of diet, sedentary lifestyle or sports, blood pH (cancer cells develop better in acidic media), hence the importance of an alkaline pH, etc.

That is, cancer depends on a combination of hereditary and environmental factors that interact with each other modifying and modulating the expression of genes (epigenetics).

These signals, once received, go to the nucleus of receptor cells and from there the necessary adjustments are made in response to such signals, consisting in the expression or activation of certain genes and silencing of others.

When a cell manages to free itself of these controls, through successive divisions, it will lead to the emergence of a clone of cells freed from these programming restrictions, that are able to leave the system circumventing all cellular safety mechanisms available to the cell, thus experiencing an inadequate proliferation (growth of the tumor mass), angiogenesis (formation of new blood vessels from which it will be), metastasis (distant dissemination), and resistance to programmed cell death (immortality).

When this occurs in somatic cells, the tumor is not passed onto the offspring; in other words, it is born and dies with the individual.

When this occurs in germ cells, it IS passed onto the offspring, causing certain families to have a higher incidence of specific cancers, because each of its cells has inherited the abnormal gene and therefore it is already predisposed, meaning, leading eventually to the development of cancer.

What needs to be done when in our families there are several cases of cancer?

You need to consult with a human genetics department for individualized assessment of each case. It is important to provide information, if you can get it, on the type of cancer or cancers and age of onset of such cancers. It also has to be verified whether molecular biology (DNA) testing was carried out in affected individuals and if the result was informative or not.

If this study has not been done and affected individuals are alive, based on the type of cancer, they may be asked for their collaboration to undergo a familial DNA study to see if it is possible to identify the mutations involved. Once the mutations have been identified, family members that have inherited the same mutation will have to be identified from those that have not inherited the mutation.

Once the study has been carried out, those individuals that have not inherited the mutation, will carry the risk of the general population to develop the disease.

Those individuals that inherited the mutation, run a higher risk compared to that of the general population, and based on the type of cancer, they should be followed up for prevention or some preventive measures should be put in place for those cases in which this is possible. For example, actress Angelina Jolie, Brad Pit´s wife, underwent a preventive mastectomy to prevent breast cancer in view of her familial past history.

If the affected individual is about to die and these studies were not performed, the treating physician should be contacted to discuss the possibility to freeze blood or tissue in a cell bank, should that material be needed in the future to run familial molecular studies.

What does the future hold for us?

In the case of personalized medicine, by sequencing, studying and knowing the genome of each individual, we will know:

    • what kind of alterations or molecular polymorphisms the individual presents.
    • which is the molecular profile of the tumor.
    • what kind of drugs will respond better based on this profile (farmacogenetics).
    • which variations you must include in your life regarding food, sports, environmental effects …. (ie epigenetic control).
    • …and when we have gained in-depth knowledge of tissue engineering and gene therapy, we will be able to repair or block the pathological gene or genes of the affected individual.

Related questions

What is cancer?

Cancer is a genetic-based disease and involves genes that contain flaws in their DNA.

What genetic flaws or genetic errors can cause cancer to develop?

Genetic flaws or errors distort the control of signaling pathways involved in the proper functioning of cell division. Control is lost due to several adverse factors, some of which have been already identified and others that remain unknown, including:

    • General lifestyle, including:  physical activity, exercise, food, diets that produce an acid pH and the stress caused by our surroundings. Toxic people who, due to the way they think or behave, affect our state of mind. Personal life experiences and the way each individual copes and responds to them. Thoughts that generate energy, which in turn, generate microenvironments that interact with DNA, thereby modulating the expression or repression of particular genes in an adaptative response to such circumstances and surroundings.
    • Exposures to radiation: sun light and melanoma (skin cancer).
    • Exposures to carcinogenic chemicals: smoking and lung cancer, asbestosis (asbestos) and mesotheliomas, environmental or ingested insecticides and pesticides, hormones, antibiotics and some additives as part of our food products.
    • Exposure to viruses, eg human papillomavirus and cervical cancer.
    • Exposures to electromagnetic fields.
    • And a long endless number of other factors, some of which are highly variable, depending on the developmental stage or rather the “involutive” stage of the geographical area in which we are living. Moreover, mankind’s continuous inventions, which due to lack of knowledge, lack of global forecast, or excessive economic ambition, destroy,  pollute and destabilize local surroundings, disturbing the balance of the area, the flora, the fauna and our own balance, since we are an integral  part of it. This all has a devastating global impact, because, in this world, everything is interconnected.


Why are environmental factors so important in the development of cáncer?

Because environmental factors shape and modulate our raw material, that is, our DNA.

CANCER, as with most common diseases that we develop, are the result of these complex interactions between our inheritance (DNA) and the environment around us (epigenetics).

This symbiosis allows us to adapt to diverse circumstances by the expression (activation) or repression (silencing) of certain genes.

Pathological environments generate the expression of harmful genes, and if these environments are prolonged in time, our health will ultimately suffer.

What are oncogenes?

Oncogenes are genes that when activated make cells acquire new properties, turning them into malignant cells.

These genes can arise by pathological activation of genes that were already silenced at the time because they fulfilled their role and now should no longer be active, for example genes that were active during our period of embryonic development and because we are no longer embryos, they are no longer needed.

In addition, these genes may have become altered because they have undergone some sort of mutation or accident in their structure that has enabled them to acquire this new property.

What are supresor genes?

Suppressor genes are genes that halt or complete a given biological process when such process has fulfilled its function.

In the case of cancer cells, suppressor genes could be defined as “police” genes that keep a close watch and detect cells that might be manifesting abnormal behaviors because some of their oncogenes or pathological genes are activated, causing the “bad” cells to die and be eliminated.

Is it possible for a cell to have both its oncogenes and suppressor genes distorted at the same time?


In such case, this cell can become a cancer cell if many other genes start to sequentially take part, become abnormal or interact among themselves.

The more altered the genes, the more disarrangement.
The more disarrangement, the more imbalance.
The more imbalance, the more pathology.
The more pathology, the more gravity.
The more gravity, the worse prognosis.

What are telomeres?

Telomeres are repetitive segments of DNA at the end of each chromosome.

What is the function of telomeres?

Telomeres protect our chromosomes so that they do not lose their genetic information.

They are the equivalent of book covers that protect the pages within a book.

How are cancer cells and telomeres related?

When the control mechanisms of telomeres fail, cancer cells start to divide in an uncontrollable manner.

What is the present-future of therapeutic strategies against cancer?

In the future, we will be able to formulate chemotherapies that will allow exclusive and selective destruction of tumor masses considering the genetic makeup of cells that form them, while respecting all the other healthy cells in our body including reproductive cells (ova and sperm), and bacteria and microorganisms that inhabit in us (microbiome), by using specific cell vectors (modified viruses) or intelligent biological weapons designed for this purpose (synthetic biology that allows us to create artificial life for specific therapeutic purposes).

Those that will be able to avoid the side effects of strategies currently used against cancer such as intoxications, burns or cosmetic deformities due to the elimination of tissues, all of which is secondary to the use of chemotherapy, radiation and surgery, respectively.

Strategies that also take into consideration epigenetic factors around us and which we know have a negative impact on our bodies such as stress, toxic exposures to health in general such as: radiations, magnetic fields, environmental pollution, acid diets, etc. and ENCOURAGE those that help us to incorporate new eating habits that allow us to maintain alkaline blood pH and teach us to be aware of the need to care for and respect our planet and our bodies without altering their circadian rhythms (biological).

Strategies that also take into consideration the genome that each of us has inherited from our parents and pass on personalized preventive actions based on the genome and the habitat of which we are a part.


Next topic: Farewell

Reviewed: 9th of January 2015