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Monday, November 11, 2013

Inquiry Exercise 20 - An Assay to Diagnose Cancer.

Challenge - Devise a serum  diagnostic assay  for Cancer

You have formed a small company  that seeks to  market a test that can  diagnose cancer before it is clinically apparent.  Angel investors have provided 5 million dollars.   In your analysis of the  current literature,  you have noted that  it has been observed that  tumor cells can shed cell content into  blood. Thus, it should be possible to identify such cell content in a serum sample  and predict the presence of cancer  before it is clinically observable.

  As in typical inquiry exercises , discuss with your group,  ask for materials  and perform experiments that may convince the instructor that you have indeed  established such an  assay.

The milestone of this inquiry exercise   will  be  the  correct diagnosis of a provided set of  patient sera ( N.B.  these are mimics and not real human sera ) .

17 comments:

  1. Since we know we are looking for something molecular, we will look into different types of tumor and the contexts in the different blood samples of these tumors. We will compare our findings to normal blood samples and view any slight differences between the different samples- Watson group

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    1. ok , but what exactly are you going to do ?

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  2. we were thinking of a test that could detect specific microvesicles within the blood stream. These microvesicles originate from the specific tumors and carry genetic information, which could help identify specific cancers and their locations. "Circulating micro vesicles (cMVs) are sub-cellular membrane-bound vesicles (30 to 1500 nm in diameter) that are released into the extracellular environment, including the blood stream, from most cell types, including tumor cells. " -http://www.carislifesciences.eu/cancer-screening-blood-testing-resources

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    1. Would microvesicles be present in serum (rather than blood ) ?

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  3. Brian, Preet, Karyn, Meye, MarissaNovember 11, 2013 at 2:17 PM

    We are comparing normal and abnormal blood samples with the sample size of .05 on each slide. Also we put 1 drop of methylene blue on each slide before looking at it through the microscope.

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  4. Do you have any antibodies that will detect proteins secreted by the tumor?

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    1. yes , this might be a very useful strategy but we don't have any such antibodies. Is there anything else that we could measure ?

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  5. what about searching for RNA and/ or MicroRNA that might have been released from circulating microvesicles specific to the cancer? will the levels of RNA or microRNA be higher in the serum in cancer positive samples as opposed to cancer negative samples? Would we need to extract the RNA from the serum before testing for it?

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    1. this is a very interesting idea , why not just try it and see !

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  6. Preet, Brian, Karyn, Meye, DyvonNovember 13, 2013 at 1:45 PM

    We think that by adding Bio-Rad Protein Assay to the serum we can see the amount of protein within the cell that initially increases evidence for tumor derived microvesicles(MV) to be present in the serum. The tumor microenviorment has cell to cell communication where MV's can transfer bioactive lipids and proteins. If it is cancer, then the cells from the serum will produce more protein to stop apoptosis.

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  7. Group McClintock- We have three ideas about how cancer may be identified through serum samples.
    The first idea is to test the levels of amino acids in the serum. From reading published studies on colon cancer the levels of amino acids have been found to be higher in cancer affected samples.
    The second is identifying exosomes in the serum.
    The third idea is to detect phosphorylation by the NIR cytoblot assay.

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  8. Group McClintock- we have tested the levels of proteins in the serum samples by using the Bio rad assay.
    We have taken 250 microliters of normal serum and of the cancerous serum.
    To each sample we have added 250 microliters of the Bio rad assay.
    The results of our first test we not significant to our purpose. Both samples turned blue, the cancerous sample was visibly more cloudy but the color change was not something that could be used to diagnose cancer.

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  9. Crick Gruop:
    We added pglo to a .5 non-cancerous and a .5 cancerous serum. After we viewed the mixture under the UV light and concluded that our cancerous serum had a greater fluorescent glow. Our measurements were a little off so next time we would be more precise when measuring samples of the serum.

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  10. Preet, Brian, Karyn, Meye, DyvonNovember 13, 2013 at 2:32 PM

    We put pGlo in the serum with cancer and the non-cancerous serum, to see whether any RNA was present. If RNA was present than it would glow, which is exactly what the serum with cancer did. Now we need to figure out how we are going to make the amount of glowing more obvious because both samples did end up glowing. The cancer serum just glowed more (Picture: the tube on the left with cancer serum)

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  11. Group McClintock
    Our group was interested in testing whether the levels of nucleic acids in the cancerous sample was larger than the that in the normal sample of serum. The assay that would identify this is pglo. Group McClintock chose to mix 500 microliters of normal and cancerous serum with 500 microliter of pglo. As a negative test we also placed 500 microliters of water with 500 microliters of pglo. Under the blacklight we were able to see differences in levels of florescence in the sample with cancerous serum from that of the normal serum and a negative result in the water sample.
    Our observations did open another question in our minds- that is why the normal serum and its preparation did show some florescence in the pglo assay test. We wonder if techniques in serum preparation could be perfected so or if it should be considered that all samples of serum may have some level of nucleic acid that would render this assay as faulty in diagnosing cancer.

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