po
Forum Elite
Topics: 39
Posts: 356
|
A 66-year-old man has noted darker urine for the past 2 weeks. A urinalysis shows hematuria. He is referred to a urologist who performs cystoscopy. A 3 cm mass is found in the dome of the bladder. Biopsies of the mass are taken and on microscopic examination show a urothelial carcinoma. Cells of this neoplasm demonstrate a single mutation causing cellular inability to hydrolyze GTP, thus resulting in cellular transformation. Which of the following oncogenes is most likely implicated in this case?
A c-abl
B c-neu
C c-sis
D k-ras
E n-myc
|
| SmokyWaters
Forum Elite
Topics: 6
Posts: 447
|
k-ras ?
|
| po
Forum Elite
Topics: 39
Posts: 356
|
 (D) CORRECT. The ras gene can be turned on by a mutation to make it an oncogene.
(A) Incorrect. This is the 'Philadelphia chromosome' in which the oncogene abl is spliced onto the bcr region of chromosome 22, resulting in increased tyrosine kinase activity. It is associated with chronic myelogenous leukemia.
(B) Incorrect. This oncogene appears to be activated by amplification and it has been associated with some breast and ovarian cancers.
(C) Incorrect. Overexpression appears to be the mechanism behind the action of this oncogene associated with brain and bone tumors.
(E) Incorrect. This oncogene appears to be activated by amplification and it has been associated with neuroblastomas.
|
|
| |
| | | |
