Untitled Deck Flashcards
What is the M phase?
The most dramatic but shortest stage of the cell cycle, lasting about 30 minutes. It is a target for chemotherapy.
What occurs during Prophase?
Chromosomes condense and become visible under a microscope. The mitotic spindle forms, and the nuclear envelope breaks up.
What is the role of MPF in Prophase?
MPF phosphorylates lamin B to dissolve the nuclear envelope.
What happens during Metaphase?
Chromosomes line up in the middle of the cell along the metaphase plate.
What occurs in Anaphase?
Spindle fibers pull chromosomes to either end of the cell, and CDK activity decreases.
What happens during Telophase?
Two new cells are formed, chromosomes decondense, and the nuclear envelope reforms around the chromosomes.
Who is Ruth Sager?
A researcher who fused normal and cancer cells to form heterokaryotic cells, proposing that cells have checkpoints that prevent cancer.
What is P53?
A tumor suppressor gene mutated in 50% of all cancers. It activates P21 to stop S phase and determines if a cell should undergo mitosis or apoptosis.
What is the problem with cancer rates in younger people?
There are increased rates of cellular aging leading to higher cancer rates among younger individuals.
What are driver mutations in cancer cells?
On average, cancer cells have 5 ‘driver mutations’ directly involved in cancer, which can be targeted for treatment.
What are the characteristics of normal cells compared to cancer cells?
Normal cells commit anoikis in semi-solid medium, have a typical karyotype, and secrete low amounts of protease, while cancer cells grow in semi-solid medium, can have aneuploid karyotypes, and secrete lots of protease.
What is Hayflick’s law?
It states that normal cells have shorter telomeres and are mortal, while cancer cells often have longer telomeres that get repaired after every division, making them immortal.
What is the role of viruses in cancer?
Viruses like Rous sarcoma virus and SV40 can cause cancer by affecting cellular mechanisms.
What is the significance of BRCA-1?
A defect in BRCA-1 increases the likelihood of developing breast cancer by 60%.
What is the goal of radiation therapy in cancer treatment?
To damage DNA to force cells to undergo apoptosis through mitotic checkpoints.
