Question
Cytogenetic studies in a 40-year-old woman with follicular lymphoma demonstrate a t(14;18) chromosomal translocation involving the bcl-2 gene. Constitutive expression of the protein encoded by the bcl-2 gene inhibits which of the following processes in this patient’s transformed lymphocytes?
| A. |
Apoptosis |
| B. | DNA excision repair |
| C. |
G1-to-S cell cycle progression |
| D. |
Oxidative phosphorylation |
Show Answer
|
Correct Answer � A Explanation |
 |
Correct answer : a Apoptosis
-
Many human cancers show abnormalities in the control of apoptosis.
-
For example, follicular B-cell lymphomas display a characteristic chromosomal translocation in which the bcl-2 gene is brought under the transcriptional control of the immunoglobulin light-chain gene promoter, thereby causing overexpression of bcl-2.
-
As a result of the antiapoptotic properties of bcl-2, the neoplastic clone accumulates in lymph nodes. Since its demonstration in follicular lymphomas, bcl-2 expression has been observed in a variety of other human cancers.
-
None of the other choices describes the function of bcl-2.