Respuesta :
Answer:
Cell cycle regulators
Explanation:
Cell division is important for an organism for growth, repair and replacement of cells and tissues. In the unfortunate event of uncontrolled cell division, the organism makes more cells than it can produce. Growing cells have four phases
G1: Growth by doubling of cytoplasm and organelles
S: Synthesis of new DNA and doubling of chromosome number
G2: A second round of growth to prepare for cell division
M: Cytokineses and the formation of two very identical cells
In an attempt to end the uncontrolled cell division one would first look into factors that initiate the G1 phase; stopping the growth of an out of control cell before it starts.
A second approach is to look into manipulating the check points at G2 and M. If there are drugs that can interfere at this point the cell will not divide uncontrollably and the potential cancer will be interrupted.
Answer:
→ inhibition or over-activities of certain proteins and enzyme
→ complications from bacteria and viral infections
Mutation is the term used to describe the uncontrolled cell division in cells.It is prompted by activities of certain cancer causing agents called carcinogenic substances. Progression of mutation is usually due to disruptions in the normal activities of cell cycle regulators.
1.Cell regulators either restrict cell division when unfavourable condition are not available(cell cycle inhibitor),or promote cell division when need for cell division arise(cell cycle promoter). Thus alteration in these activities lead to cancerous growth either by blocking activities of cell cycle inhibitors, or over activities of cells cycle promoters.
1a)
Overactivities of positive growth factors leads to the formation of oncogenes cancer cells, and proto-oncogenes that are prone to cancer cells. Certain growth promoting proteins in the pro-oncogens usually send growth signals to growth factors receptors for cascade events which promotes cells growth through cell division. Therefore mutation in the amino acid sequence of these proteins may prompted these proteins to send signals in absence of growth factors which may promotes oncogen formation from uncontrolled cell growth(mutation) and therefore cancer growth.
In addition mutation in certain proteins which promotes activation of protein (Cyclin) , which activates enzymes needed for cell division in cells also promotes oncogene formation,.which ever ways both leads to rapid cell division.
Therefore any drug that can block activities of these proteins or prevented their mutation , will prevent uncontrolled cell division(mutation )and therefore oncogenes formation, thus preventing proto-oncogenes and therefore inhibits cancer growth.
Alternatively, any drug which inhibits activities of enzymes which promotes cells division, will definitely prevent uncontrolled cell division that leads to oncogens.
1b).
In addition certain protein called tumor suppressor proteins, inhibits cell division when DNA is damaged or altered. Example is protein p53.it blocks early phase of cell cycle from G1 to S transition phase in response to DNA damages.It does this by binding to the damages cells, promotes cell cycle inhibition,so that DNA can under go repairs, and later releases the cell for normal cell division afterwards.In case DNA can not be repair ed it promotes cells apoptosis or cell death.
Cancer cells inhibits activities of p53, or made its mutant forms which will not be suppressing. Thus mutated DNA is expressed and oncogens are produced.
Thus any drug that can prevent the damaged DNA from replicating, will prevent formation of abnormal cells and therefore prevent uncontrolled growth.
2
Certain viral infection(human papilomavirus) which causes cervical cancer,helicobacter pyroli(colon cancer), M. tuberculosis, which causes tuberculosis(which may lead to lung cancer )are other causes of cancer., Therefore taken drugs that boost body immunity and immune responses, will also prevent cancer growth.
Explanation:
