Carcinogenesis requires that a single cell or one of its descendents undergo a s
ID: 39204 • Letter: C
Question
Carcinogenesis requires that a single cell or one of its descendents undergo a series of rare genetic and epigenetic changes that permanently alter the expression of at least five to eight genes. Thus, it is not surprising that many cancer cells assayed in cell culture dishes were found to have a very high rate of mutagenesis.
A. What are three systems that are often defective in cancer cells whose role is to ensure the integrity of the genome?
B. The increased mutation rate speeds cancer progression by increasing the likelihood that a cell will acquire additional properties that contributes to carcinogenesis. Name four of the eight typical properties of cancer cells.
C. UV and ionizing radiation are known to cause cancer because they are mutagens that damage DNA. How, then, are the many anticancer therapies that act by damaging DNA, including ionizing radiation and many drugs, so effective at shrinking tumors?
Explanation / Answer
a. cel cycle check points play an important role in controlling genome integrity
b. metastasis ie.e they migrate to other site.
angiogenesis cacn cause new capillary growth to supply blood and nutrients to cancer cells
malignant i.e. uncontrolled growth
insensitive to apoptosis signalling.
c. drugs that are used to treat cancer have specfic cancer cell surface receptors which release th cytotoix drug selectively to these cells.
where as radiation therapy for cancer treatment uses x ray, gamma, proton or electron beams to treat cancer. these are high energy radiations but low doses are used in treatment of cancer.