Sunday 22 May 2016

FEATURES OF CANCER CELLS

MAIN FEATURES OF CANCER CELLS

These are also known as hallmarks of the cancer.these hallmarks are develop to understand the complex nature of the cancer.with the help of these hallmarks we can reduce the complexity of the cancer into small understanding concepts.

SELF SUFFICIENCY OF CANCER CELLS GROWTH:-

                                                                          cancer cells stimulate their own growth. the growth of the cancer cells is more self sufficient. because they does not require any signal to grow. some of the cancer cells have ability to develop their own signals.for example sarcomas develop its own TGF(tumor growth factor -alpha)



 INSENSITIVITY TO ANTI-GROWTH  SIGNALS

As we know that the growth of the cancer cells are abnormal type.so they are insensitive to the anti-growth signals.it means when it is required to stop the growth of the cancer cells then anti growth signal are produce by the protein.  but because of insensitivity to the anti-growth signals cancer cells does not respond to these signal and continuously increasing its growth.

                                                                 it is mostly require to control the division of the cancer cells.these processes are orchestrated by a protein known as tumor suppressor genes. these genes are responsible to control the growth of the cells. in case of cancer these tumor suppressor genes become altered so that they can not prevent the cells division.

           there is a important features of the normal cells is contact inhibition.the normal cells are stop dividing when their is a contact between two or more normal cells. but cancer cells have no contact sensation. it means that when they comes in contact with each other they are not stop to dividing itself.


EVADING PROGRAMMED CELL DEATH

This is the process in which normal cells have a property to self cell suicide. it  is most important feature of the normal cells. in this process when the cell become damage or infected then cell is programmed to self suicide this process is known as "apoptosis". it means cell destroyed itself when their is a damage in the cell.
                                  but in case cancer cells this feature is skipped. it means cancer cells are not programmed to such type of action. it means that if their is any damage in the cancer cells then they will not destroyed itself.


LIMITLESS REPLICATIVE POTENTIAL 

in case of normal cells : normal cells have limited dividation of cells or limited number of dividing. after the limit cells does not able to further dividing of cells. because DNA at the end of the chromosome is known as telomeres become short. due to this barrier the further dividing process does not take place.

in case of cancer cells:  cancer cells has ability to skip this barrier by manipulating anzymes which increase the length of the telomeres.so that they can abnormally divided into large number of cancer cells.

       their are two types of tumor suppressor proteins pRB and P53. these are the proteins which are responsible for continuous development of the cells until they reached at a position of crisis.



DEVELOPING BLOOD VESSELS

Angiogenesis is the process by which new blood vessels are formed. Cancer cells is  able to start this process, ensuring that such cells receive a continual supply of oxygen and other nutrients.
Normal tissues of the body have blood vessels running through them that deliver oxygen from the lungs. Cells must be close to the blood vessels so that they get enough oxygen for them to survive. New blood vessels are formed during the development of embryos, during wound repair and during the female reproductive cycle. An expanding tumour requires new blood vessels to deliver adequate oxygen to the cancer cells, and thus exploits these normal physiological processes for its benefit. To do this, the cancer cells acquire the ability to orchestrate production of new vasculature by activating the 'angiogenic switch'. In doing so, they control non-cancerous cells that are present in the tumor that can form blood vessels by reducing the production of factors that inhibit blood vessel production, and increasing the production of factors that promote blood vessel formation.


TISSUE INVASION AND METASTASIS

Cancer cells can invade surrounding tissue and spread  to distant body parts.
Cancer cells can attack or invade to neighobring tissues. It is what dictates whether the tumor is well-wishing or malignant. The cancer cells have to undergo a multitude of changes in order for them to acquire the ability to metastasis. this is the large process that starts with local invasion(to attack) of the cells into the surrounding tissues. Then they have to invade blood vessels, survive in the very strict environment of the circulatory system, exit this system and then start dividing in the new tissue.



  

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