Over expression in cancer and normal cells - cell bio (May/03/2005 )
hey everybody..this is the second of 3 tough question I have come across while doing some preliminary work before starting my research over them summer.....could some one give a thorough and complete explanation for it( you can send it to my email at tellanish@hotmail.com...thanks a lot!
Over-expression of Myc is a common feature of many types of cancer cells, contributing to their excessive cell growth and proliferation. By contrast, when Myc is hyperactivated in most normal cells, the result is not excessive proliferation but cell-cycle arrest or apoptosis. How is it that over-expression of Myc can have such different outcomes in normal cells and cancer cells?
Many transformed (i.e., cancerous) cell lines can be "detransformed" if mixed in culture with normal parental cells; that is, they no longer exhibit their cancerous
phenotype or behavior. For instance, when non-transformed C3H10 cells are placed together with a transformed offspring cell line, MC4AB10, the latter become normal in phenotype. Describe experiments to determine if this effect results from cell-to-cell contact between the two types of cells or from the release of a hormone-like factor by the non-transformed cells.
Another tough question but i anxiosuly await a response
I can answer this but it sounds like an exam question so I am not sure I should ... is it? Do you have some ideas and I can guide you in the right direction?
Overexpression of myc and many other oncogenes induces expression of cell cycle inhibiters in normal cells and so induces cell cycle arrest or apoptosis. Cancer cells have defects in cell cycle regulation pathways and so fail to arrest.
Ok so I suggest you do some research ... have you looked through Alberts, Lodish and other books? The answer to the first part about myc is in Alberts, nearly word for word - bascially expands on what AJAMES said. If you don't have or read this book, I suggest you do, it's always a great place to start.
Also do you have access to PubMed, check there. Many myc reviews and other reviews on oncogenes. Also on the NCBI website there is a part where you can search books including those I mentioned above ... you can find tons of info for free there.
Second part ... do some research into what experiments one can perform with the following:
http://www.corning.com/lifesciences/cell_c...le_supports.asp
There is a diagram there that should give you some ideas of how to design your experiment.
Over-expression of Myc is a common feature of many types of cancer cells, contributing to their excessive cell growth and proliferation. By contrast, when Myc is hyperactivated in most normal cells, the result is not excessive proliferation but cell-cycle arrest or apoptosis. How is it that over-expression of Myc can have such different outcomes in normal cells and cancer cells?
Many transformed (i.e., cancerous) cell lines can be "detransformed" if mixed in culture with normal parental cells; that is, they no longer exhibit their cancerous
phenotype or behavior. For instance, when non-transformed C3H10 cells are placed together with a transformed offspring cell line, MC4AB10, the latter become normal in phenotype. Describe experiments to determine if this effect results from cell-to-cell contact between the two types of cells or from the release of a hormone-like factor by the non-transformed cells.
Another tough question but i anxiosuly await a response