Discuss the role of telomeres in cell maintenance, ageing, and disease

Tumors associated with breast cancer usually arise from either epithelial cells or fibroblasts. Because optimal treatment differs depending on the cellular origin of the tumor, it’s important for doctors to determine which cell type is present in a tumor. Unfortunately, the distinctive morphology of epithelial cells is lost when they become cancerous, so this determination cannot be made based on cell shape alone. How might determination of the class(es) of intermediate filaments present in tumor cells aid a doctor in figuring out which cell type is involved in the tumor?

Reports in the media about stem cells usually state that they “turn into any kind of cell in the body.” Explain why this statement is only partially correct, including a description of how a stem cell maintains the population of stem cells.

Describe experiments using marker molecules that have been done to elucidate important properties of (1) tight junctions and (2) gap junctions.

Recall the experimental techniques used to study microtubules and intermediate filaments.

Mutations in p53 are commonly associated with malignant tumor formation. Do deleterious mutations in p53 usually lead to a loss of function or gain of function of the protein?

Which of the following describes a mechanism by which microtubules are known to be stabilized?     Conformational changes undertaken by beta-tubulin as it hydrolyzes GTP.     Binding of microtubule binding proteins, such as Tau.     Shortening of the GTP cap.     Increasing the proportion of alpha-tubulin subunits relative to beta-tubulin subunits.

Cancer is a complicated series of diseases characterized by over-proliferation of cells within a tissue. While in some instances the primary tumor is the ultimate cause of death, in many cases the primary tumor metastasizes, or moves, through the lymph system to invade other tissues. The migration of tumor cells requires changes in the adhesion properties of the cell that allow it to move and invade more readily.  There are several molecules involved in cell-to-cell connections and cellular architecture: laminins, matrix metalloproteinases, cadherins, and integrins. While mutations in genes that control the cell cycle or recognize DNA damage are the causes of tumor cell formation, tumor cell spread to other tissues may be caused by mutations in the genes the code for these extracellular proteins. The loss of cellular connections, cellular identification and signaling, and tissue structure may lead to the release of expanding tumor cells into the circulatory and lymphatic systems. Once…