There is a group of gene which reduce the probabilities of occurring cancerous cell or inhibit the abnormal proliferation by different metabolic activities. And a cell with the mutated Tumor suppressor gene or functionally reduced TSG can progress it to cancer.
Example:-
1. P53 gene:- The protein produced by this gene is of 53 kd, hence the name. It prevent a cell from completing a cell cyclem, 1) if its DNA is damage and 2) the cell is not prepared or injured for normal proliferation. So in these cases it halts the cell cycle until the damaged is reapired and if the damage is too critical then it triggers the cell to commit suicide by programmed cell death of Apopstosis. 70% of colon cancer, 50% of breast cancer and 50% of lung cancer is for mutation of this gene.
2. Rb gene:- it the condition are not adequate to perform the cell divison this gene stops the cell cycle in S phage by blocking the transcription factor c-myc and c-fos, which are necessary factors for the mitosis. And when the stituations become adequate it gets phosphorylated and releases a E2F factor which activate c-myc and c-fos and cell cycle continued.
Fuctions:-
1. repress the genes that are essential for continuing the cell cycle.
2. trigerring the apopstosis in case of critical damge.
3. couples the cell cycle to DNA damage so that it cannot continue until the damage is repaired.
Example:-
1. P53 gene:- The protein produced by this gene is of 53 kd, hence the name. It prevent a cell from completing a cell cyclem, 1) if its DNA is damage and 2) the cell is not prepared or injured for normal proliferation. So in these cases it halts the cell cycle until the damaged is reapired and if the damage is too critical then it triggers the cell to commit suicide by programmed cell death of Apopstosis. 70% of colon cancer, 50% of breast cancer and 50% of lung cancer is for mutation of this gene.
2. Rb gene:- it the condition are not adequate to perform the cell divison this gene stops the cell cycle in S phage by blocking the transcription factor c-myc and c-fos, which are necessary factors for the mitosis. And when the stituations become adequate it gets phosphorylated and releases a E2F factor which activate c-myc and c-fos and cell cycle continued.
Fuctions:-
1. repress the genes that are essential for continuing the cell cycle.
2. trigerring the apopstosis in case of critical damge.
3. couples the cell cycle to DNA damage so that it cannot continue until the damage is repaired.
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