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Question

A study of malignant neoplasms reveals that some of them have a greater potential for invasion and metastases. Analysis of the cells of cancers that have metastasized reveals a mutation which results in decreased cell surface expression of E-cadherin.

Which of the following genes is most likely mutated to produce these findings?


A beta-catenin

B BRCA-2

C Cyclin D

D NF-1

E RAS

F Rb

G RET

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Answer / Explanation:

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(A) CORRECT.

Beta-catenin binds to the intracellular portion of cadherins, which anchor cells together, and the loss of this function results in less cell adhesiveness that favors tumor cell infiltration and metastases. Beta-catenin also binds to a nuclear transcription factor that increases cell proliferation, and loss of normal beta-catenin function leads to cell proliferation.
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