Human body operates as a society or an ecosystem. The single members are represented by the cells, which can replicates through cellular division and organize themselves into collaborative complexes called tissues. This society is really special: the main rule is the self-sacrifice and not the survival of the stronger one. In order to coordinate their behaviour, cells send, receive and interpret various and elaborated extracellular signals that serve as “social control” and basically order to each and every one of them how to operate. As a result, every cell behaves in a socially responsible manner, remaining quiescent, growing, dividing or even dying for the superior good of the entire organism. Every disturbance, which alters this perfect harmony, creates serious problem to a multicellular organism such as our body.
Everyday in our body billions of cells endure DNA mutations, endangering the stability of the social controls. In fact, DNA mutations can confer selective advantages to the cells, allowing them to grow faster than the neighbour cells, and potentially, establishing a mutant clone with high proliferating capacity.
According to the “somatic mutation theory”, the onset of a mutated “selfish clone” underpins cancer pathogenesis. Generally, this clone harbours multiple genomic alterations, which deregulates the activity and function of proteins involved in the various cellular mechanisms such as proliferation, metabolism and invasiveness.
Cancer’s numbers are just astonishing. In the USA, one out of three people get cancer whereas one out of four dies from it. These scary numbers are not only linked with the increase of our life expectancy, but also to the prolonged exposure to carcinogenic and mutagenic agents, which plague the technologic and globalized world where we live, and to corrupted lifestyles. Worth mentioning, several studies include also psychosomatic causes in the cancer pathogenesis and also therapeutic prognosis: cancer study field is able to embrace all the disciplines.
The scientists Douglas Hanahan and Robert Weinberg, in a review entitled “Hallmarks of Cancer”, have masterfully explained the biological basis of the cancer.
The hallmarks of cancer are biological capabilities that cells have to acquire during the multistep development of human tumors. In the first review wrote by the two scientists, six major capabilities were depicted:
- Sustaining proliferative signalling
- Evading growth suppressors
- Activating invasion and metastasis
- Enabling replicative immortality
- Inducing angiogenesis
- Resisting cell death
Eleven years later, thanks to several advancements in the field, the same authors wrote a new review including other four hallmarks that need to be acquired during the tumorigenic process:
- Deregulating cellular energetics
- Avoiding immune destruction
- Tumor-promoting inflammation
- Genome instability and mutation
With a “Hallmarks of cancer article series”, TakeitScience staff proposes to explain to every readers, independently from his/her background, the biological basis underlying cancer onset and progression. After a series of article recapitulating all the scientific knowledge on the topic, we also propose to review other cancer theories such as the “tissue organization field theory” and the “psychosomatic theory”. These new hypothesis bear a holistic approach toward cancer, and, intriguingly, new studies are also starting to scientifically substantiate them with experimental evidence.
Next week, in the first article of the series we will talk about the hallmark “sustaining proliferative signalling”.