SmokyWaters
Forum Elite
Topics: 6
Posts: 458
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A
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| SmokyWaters
Forum Elite
Topics: 6
Posts: 458
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this was A :S I wrote A there... :S
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| po
Forum Elite
Topics: 39
Posts: 356
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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.
(B) Incorrect. BRCA-2 and BRCA-1 act as tumor suppressors.
(C) Incorrect. Cyclin D operates within the cell cycle machinery.
(D) Incorrect. NF-1 codes for the protein neurofibromin, which acts in the RAS pathway and promotes GTPase activating factors which facilitate conversion of RAS from active to inactive. The loss of normal NF-1 leads to loss of cell control.
(E) Incorrect. RAS oncogene mutations result in loss of control of cell proliferation; there is no direct effect upon cell surface proteins.
(F) Incorrect. Rb is a tumor suppressor gene.
(G) Incorrect. RET codes for a protein that acts as a cell surface receptor for growth factors. Mutations lead to loss of cell control because the receptor remains active even without binding of the growth factor.
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