Cancer considered as one of the most dangerous disease all over the world. Some people are lucky enough to survive cancer, but most of the people that suffer from cancer died from the disease.
What Causes Cancer?
Cancer starts with just a small population of tumor-initiating cells, exhibiting exhibit several stem cell-like properties. Adult stem cells (SC) have something to do with the regeneration and maintenance of our body tissues and account for one out of every 6 million cells. Every tissue has their own unique population of SCs that can be found in regions known as niches. In the SC niche, the SCs exist in a unique dormant state referred as quiescence, and remain in this state until they got activated.
The moment that they become active, these stems cells, go through two stages of development known to many as proliferation and differentiation. For the duration of proliferation, biochemical cues cause the cells to reproduce, which results in an expanded population of the same cells. Differentiation stops the proliferation with biochemical cues, causing the proliferating cells to differentiate into a specific type of cell. Once a stem cell got distinguished, it has a limited life span and limited in how many times it can replicate itself. The number of times a differentiated cell can reproduce known as Hayflick number.
Cancer occurred whenever a stem cell stuck in proliferation, and is, therefore, not given the cues in differentiating. This situation results in a frequently expanding population of undifferentiated cells that can never exist anywhere in the body (metastasis), but also have limitless life spans (no Hayflick number).
The biochemical cues for production and discrimination based on genes specific to each tissue. As a general rule, genes initiating proliferation called oncogenes while genes, which initiate differentiation, called tumor suppressors. Cancer, therefore, could be observed as an over-activation of oncogenes accompanied by the inhibition of tumor suppressors. It is the ratio of oncogenes to tumor suppressors, which determines the assertiveness of the cancer.
Another key piece in the development of cancers is a process known as angiogenesis. Angiogenesis is the physiological process, which tumors are using so that they could recruit new blood vessels in order to sustain their recurrent growth. They do this by over-expressing genes, initiating and directing the growth of new, leaky blood vessels from existing ones. Both angiogenesis and the impulsive formation of new blood vessels (vasculogenesis) initiated by unique combinations of genes.