Many of the mutations in cancer samples are not necessarily driver mutations, but rather passenger mutations that are along for the ride.  Just because the tumors with a strong environmental component possess a higher frequency of mutations does not mean more oncogenes or more failure of tumor suppressors is occurring. Hematologic childhood cancers have a lower frequency of mutations than tumors with a strong environmental component such as lung cancers and melanoma; WHY?

Dr. Serena Velazquez lands a coveted post-doc position at Johns Hopkins following completion of her MD/PhD in cancer therapeutics to treat late-stage pancreatic cancer using a mouse model. Her post-doc will be devoted to targeted mutagenesis of replicative enzymes to halt cell division in cancerous cells. She reviews mitosis and meiosis before reporting for her first day of work.   1)  Cancer is essentially unregulated gene growth. Cancer cells sometimes have LOF mutations that affect the production of checkpoint proteins so nothing prevents the cells from continually moving forward and reproducing. If a LOF halted the cell cycle but DNA was still replicated, what check point was affected? a)  The G1 checkpoint. b) The G2 checkpoint. c) The G0 checkpoint. d) The Metaphase checkpoint.

"In most differentiated tissues, daughter cells retain a memory of gene expression patterns that were present in the parent cell through mechanisms that do not involve changes in the sequence of their genomic DNA" is true or false.

A microarray is a technique used to develop a profile of the messenger RNA being transcribed by cells at a particular point in the life cycle of the cell. This allows the researcher to detect the expression of particular genes at a particular time. Microarrays have proven very useful in the detection of genes involved in certain types of cancer. If the product of a particular gene functions as a tumor suppressor, which piece of evidence do you think would be the most useful in the diagnosis of a cancer due to a nonsense mutation in this tumor-suppressor gene? (Hint: Don't worry about what a microarray is. Think about what you know about mitosis, cancer, and types of mutation.) O The tissue sample responds to treatment with a mitosis-promoting compound. O The tissue sample shows a high level of gene expression relative to a control (noncancerous) sample. O The mRNAs for the targeted tumor suppressor sequence are not being produced. O The mRNAs for cyclins and kinases show unusually high…