40 - MCB 142 Professor Georjana Barnes 11/28/07 Lecture 40...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
MCB 142 Professor Georjana Barnes 11/28/07 Lecture 40 ASUC Lecture Notes Online (formerly Black Lightning) is the only authorized note-taking service at UC Berkeley. Please do not share, copy or illegally distribute these notes. Our non-profit, student-run program depends on your individual subscription for its continued existence. These notes are copyrighted by the University of California and are for your personal use only. Sharing or copying these notes is illegal and could end note taking for this course ANNOUNCEMENTS Office hours today: 12:30-1:30PM, 301 Barker LECTURE REVIEW We discussed these three points last time regarding the genetics of cancer. There are many types of cancers out there but all cancers are caused by inappropriate and inaccurate cell proliferation. What we know is that cancers result from mutations in genes that are involved in cell growth and proliferation. Before we can understand cancer, we need to understand normal events of cell growth and division. These are the themes we’re going to deal with this week: the first is that cancer, as I’ve emphasized, is a disease of genes that are involved in the cell’s normal ability to grow and divide. What’s also true is that chemicals in the environment that increase the mutation of genes increase the probability of cancer. The third point is one that I want you to appreciate so that you can understand the difference between cancer and other heritable diseases we’ve been discussing in this course, like cystic fibrosis. The differences are shown here. In those non-cancerous genetic diseases, one or two copies of the mutant gene are inherited through the germ line in a family of organisms. The critical thing to remember is that those defective gene(s) are present in all the cells of that organism. That differs significantly from the situation in cancer and cancer genetics. Some people inherit mutations in genes that predispose them to cancer; it’s not cancer, but what happens is that most mutations that cause cancer occur in somatic cells in one type of tissue. All the cells in that organism do not have the mutant genes that are causing cancer in one kind of somatic cell. The B point of number 3 is that you need multiple mutations in several genes that need to be accumulated over time (and in clonal descendants of a single somatic cell). A single somatic cell sustaining multiple mutations will be enough to cause the phenotype of cancer. The key point to remember about the cell cycle is that there are many genes and proteins that control the events of the cell cycle. The second point here is that whatever these factors are, they allow progression through the cell cycle when everything is ok. But they can also cause the cell machinery to slow down or stop if the system detects damage to the genome or malfunction in the machinery of the cell carrying out the cell cycle itself. In those situations, the cell cycle slows down or stops. EVENTS OF THE CELL CYCLE
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/04/2008 for the course MCB 142 taught by Professor Slatkin during the Fall '08 term at University of California, Berkeley.

Page1 / 5

40 - MCB 142 Professor Georjana Barnes 11/28/07 Lecture 40...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online