Question

Describe the results of the experiments shown below in which human bladder cancer DNA was used. For part B, why would a researcher complete experiment such as this? In your answer, please differentiate between proto-oncogene and oncogene, and be sure to describe the methods of DNA transfection and foci detection. fordi detected proto-oncogene transfection after transfection cloned oncogene 9.4 acquired fragments carrying oncogene NIH 3T3 genome - fragment reactive with probe b c d e f g h i j k 350 bp fragment Southern Blot analysis using a radiolabeled probe directed versus the oncogene H-ras: Lanes a,k are human tumor DNA:lane lis untransfected NIH3T3 cells; Lanes b-jare NIH3T3 cells transfected with human tumor DNA subjected to sequence analysis to determine mutation responsible for activity

Answer 1

Human bladder cancer sample was used in this particular experiment. Southern blotting was used as a molecular biology technique in carrying out the experiment. The oncogene present is H Ras. H Ras is a protein which is made by the HRAS gene. The H Ras protein falls under the category on Ras family of oncogenes.As H Ras behaves like a GTPase,it behaves like a molecular switch which activates and deactivates depending on the presence of GTP and GDP. It is turned on in the presence of GTP and turned off in the presence of GDP. The function of the H Ras oncogene is regulating cell differentiation and division. There lies difference in the terms proto oncogenes and oncogenes. Proto oncogenes are the ones that might be exposed to mutation and result in a normal cell behaving like a cancerous cell. Oncogenes are the already mutated form of the proto oncogene. Transfection takes place in the NIH 3T3 cell line which is a widely used and well known fibroblast cell line. Lane A contains untransfected cells whereas the remaining lanes contain transfected cells. DNA transfection is a well known technique used for gene transfer. Here the DNA of the cancerous human bladder is to be transfected in the NIH 3T3 cell line. Methods like electroporation is used for this purpose. Other methods can be transfection based on lipososme and calcium phosphate exposure. Lastly, foci detection can be carried out using magnetic resonance imaging technique.