Futurelearn.com is a MOOC with primarily UK universities. I signed up for several Futurelearn courses, and Inside Cancer is the first. The first week of this six-week course was too basic for me, but I will probably take the remaining six weeks because I think the material will be more advanced. This post contains my notes and test scores.
Inside Cancer, Dr. Monma Hejmadi, University of Bath
Week 1 Video 2
Cancer is uncontrolled proliferation of cells, caused by various triggers such as exposure to viruses or carcinogens or age. Triggers can elicit 3 responses (1) divide, (2) proliferate, (3) divide. Cancer cells override this.
Cancers arise from within and cannot spread to other individuals. Almost all species develop cancer. The naked mole rat does not develop cancer. This 35-g rodent lives underground and lives about 30 years. Cell growth is regulated by contact inhibition, a process in which cells stop dividing when they come in proximity with other cells. Could investigation help us stop cancer?
Are cancer susceptibility genes in all species? Yes, from hydra to humans. The genes (e.g., Myc) have been around for up to 600 million years. These genes are thought to play an important role in regulating, differentiation, growth, and death. Most have normal function except when internal or external signals disrupt the balance.
Week 1 Video 3 – Why do you get cancer? (11:00)
One in 3 people develop cancer. DNA mutations happen one in every 2 million events. Ten million cells are replaced every second.
Are cancer types/frequencies identical across populations? No. Japan has higher gastric cancer rate than US, and Japanese who have migrated to US have lower rate than those in the Japanese population, therefore the environment plays a larger role than cancer susceptibility genes.
Lifestyle and environment are largest contributors, age is second largest contributor. High scrotal cancer was found in chimney sweeps in 1800s. First evidence of environmental role. Obesity, lack of exercise, and high calorie diets also increase risk of certain cancer types. Viral infections can also cause cancer (e.g., human papilloma virus causes cervical cancer, vaccine preventable, other insults also increase risk). Age is responsible for 60% of cancer: longevity increases cancer risk. Why? Weaker immune system, increased exposure to carcinogens, exposure to hormones, greater oxidative damage.
Week 1 Video 4 – DNA Mutations (3:14)
Genomic instability is foundation for most cancer research. Cancers arise through evolutionary process. (Dobzhansky: “Nothing in biology makes sense except in the light of evolution.” This is true for cancer as well.) Not all cells with mutations will become cancerous. But cells that proliferate have selective advantage, and subpopulations grow even faster. Cancer is the result of accumulations of mutations.
Week 1 Video 5 – Survival of the nastiest: Cell division and cell death
Focus on cell division and cell death. Cells are highly varied (e.g., pancreas cells, red blood cells, nerve cells). All cells original from fertilized egg. Cell differentiation produces specialized cells, which don’t divide often.
Apoptosis, or cellular suicide, gets rid of excess cells (unconnected nerve cells in brain) or damaged cells (e.g., UV damaged cells). Tumor cells have lost the ability to undergo apoptosis, which leads to uncontrolled proliferation. The growing cells accumulate new mutations.
Video 6 is a basic illustration of cell division.
I scored 15/15 on the Week 1 test.
Week 1 Video 2
Cancer is uncontrolled proliferation of cells, caused by various triggers such as exposure to viruses or carcinogens or age. Triggers can elicit 3 responses (1) divide, (2) proliferate, (3) divide. Cancer cells override this.
Cancers arise from within and cannot spread to other individuals. Almost all species develop cancer. The naked mole rat does not develop cancer. This 35-g rodent lives underground and lives about 30 years. Cell growth is regulated by contact inhibition, a process in which cells stop dividing when they come in proximity with other cells. Could investigation help us stop cancer?
Are cancer susceptibility genes in all species? Yes, from hydra to humans. The genes (e.g., Myc) have been around for up to 600 million years. These genes are thought to play an important role in regulating, differentiation, growth, and death. Most have normal function except when internal or external signals disrupt the balance.
Week 1 Video 3 – Why do you get cancer? (11:00)
One in 3 people develop cancer. DNA mutations happen one in every 2 million events. Ten million cells are replaced every second.
Are cancer types/frequencies identical across populations? No. Japan has higher gastric cancer rate than US, and Japanese who have migrated to US have lower rate than those in the Japanese population, therefore the environment plays a larger role than cancer susceptibility genes.
Lifestyle and environment are largest contributors, age is second largest contributor. High scrotal cancer was found in chimney sweeps in 1800s. First evidence of environmental role. Obesity, lack of exercise, and high calorie diets also increase risk of certain cancer types. Viral infections can also cause cancer (e.g., human papilloma virus causes cervical cancer, vaccine preventable, other insults also increase risk). Age is responsible for 60% of cancer: longevity increases cancer risk. Why? Weaker immune system, increased exposure to carcinogens, exposure to hormones, greater oxidative damage.
Week 1 Video 4 – DNA Mutations (3:14)
Genomic instability is foundation for most cancer research. Cancers arise through evolutionary process. (Dobzhansky: “Nothing in biology makes sense except in the light of evolution.” This is true for cancer as well.) Not all cells with mutations will become cancerous. But cells that proliferate have selective advantage, and subpopulations grow even faster. Cancer is the result of accumulations of mutations.
Week 1 Video 5 – Survival of the nastiest: Cell division and cell death
Focus on cell division and cell death. Cells are highly varied (e.g., pancreas cells, red blood cells, nerve cells). All cells original from fertilized egg. Cell differentiation produces specialized cells, which don’t divide often.
Apoptosis, or cellular suicide, gets rid of excess cells (unconnected nerve cells in brain) or damaged cells (e.g., UV damaged cells). Tumor cells have lost the ability to undergo apoptosis, which leads to uncontrolled proliferation. The growing cells accumulate new mutations.
Video 6 is a basic illustration of cell division.
I scored 15/15 on the Week 1 test.
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