00:02
So, cells in a tumor contain mutated copies of a particular gene that promotes tumor growth.
00:07
Gene therapy can be used to introduce a normal copy of the gene into the tumor cell.
00:12
Would you expect this therapy to be effective if the mutated gene were an oncogene or a tumor suppressor gene? explain the reasoning.
00:21
So, let's define what is an oncogene.
00:24
Oncogenes usually promote cell growth or cell division when it's normal.
00:36
But when you have a mutation, this mutation will cause overactive oncogene, or sometimes we call gain -of -function.
01:04
So, basically, the oncogene works uncontrollably and causes too many cell growth or cell divisions.
01:14
So, overactive is the key word.
01:38
And obviously, uncontrolled cell division causes too many cells to develop into tumors or cancer.
01:44
So, if you introduce a normal copy of an oncogene, it's not going to correct the issue because the mutated copy is still there.
01:53
So, add a normal oncogene copy, it still increases the growth and cell division.
02:15
And so, it's not going to help with the cancer.
02:18
It's not going to stop the cancer.
02:20
So, actually, the increased cell growth makes things even worse.
02:26
So, if the gene mutated is an oncogene, introducing additional copy, which is normal, is not going to help with the situation because a normal copy would increase cell growth and division anyway.
02:40
So, it just makes things worse.
02:42
But if this mutated copy is a tumor suppressor gene, so what is that? so, according to name of the tumor suppressor, you know that tumor suppressor basically is suppressed tumor.
03:05
So, they are basically prevent the formation of tumors or they would promote cell deaths...