Question

Genetics

What are some causes of cancer?

Cancer can arise spontaneously, but can also be induced as a result of environmental factors such as sun exposure and smoking. If you were in charge of allocating resources for cancer prevention, would you emphasize research on curing cancer, or education about cancer prevention? Explain your answer.

Although tobacco smoking is responsible for a large number of human cancers, not all smokers develop cancer. Why is this?

Pick a specific tumor suppressor gene or oncogene and explain how this gene can lead to or prevent cancer. Be sure to focus on the mechanism of how your chosen gene impacts the cell cycle. You can alternatively pick a virus that has been associated with cancer and explain how that virus impacts the cell cycle and ultimately leads to cancer.

Answer 1

1.cancer is one of the biggest worldwide concern. Recently it has been proved in varous studies that cancer will cross heart disease and will be the biggest cause of death in few comming years.

cancer can be caused by both genetic factors abnormality and environment factors.

genetic factors are generally responsible for formation and development of cancer, whereas environmental factors contribute to the promotion and progression of cancer.

2. Cancer can be caused due to various reasons as explained above. As a head of cancer prevention resources allocation committie, I realise the importance of both the areas, that is, cancer curing and cancer awareness and therefore in my opinion the resources should be divided as 70% for cancer curing and 30% for cancer awareness.

the reason behind this decision is cancer research is happening world wide but still we donot have enough knowledge to cure one, and day by day new forms of cancer is developing. studies have shown that same cancer can affect two person differently thus requiring different types of medicines or approches to cure it due to their different genetic makeup. Now the awareness is also important because most people do not know that they are vunrable to cancer and even small bad habbits like smoking can make them more succeptible to cancer. Therefore some of the resources should be spend on awareness of cancer.

3. Not all smokers gets cancer this is because, smoking is an environmental factor it usually enhance cancer, but cancer is generally induce by genetic factors mutations. Now if two persons are equally smoking but one is getting cancer and other not, it might be because that one of them is already vuneable to cancer due to some genetic mutations or may have weak immune system,whereas other one has a strong immunity and is genetically not vunreable to cance.

4.Lets take p53, it is a tumor suppressor gene,which means to cause cancer the function to p53 should be lost.

Tumor suppressor are involved in cell cycle checkpoints or causing apoptosis, that is , making sure that no cell with defect or mutation grows and hence, called as tumor suppressor genes.

p53 is invoved in DNA damage checkpoint and arrest cell at G₁ phase of cell cycle.

Damaged DNA activates ATM which is a protien kinase, which activates another protien kinase chk2. both of these kinases phosphorylates p53 and stablise it, therefoe increasing it cellular concentration. p53 is a transcription factor which when phosphorylated, induces transcription of p21, which binds to cdk2-cyclin E and thus deactivating it.

Deactivation of cdk2- cyclin E do not allow it to enter into S- phase and thus cell gets arrest at G₁ stage.