13. The cap binding protein (elF4E), which is involved in the global regulation of translation, is highly regulated in eukaryotic cells. In an experiment, a researcher transfected mammalian cells with (elF4E) gene for itsoverexpression. Due to this, the cells will undergo
(1) Apoptosis
(2) neoplastic transformation
(3) no change
(4) differentiation
Introduction
The eukaryotic translation initiation factor 4E (eIF4E) plays a pivotal role in regulating protein synthesis by binding the 5’ cap of mRNAs and facilitating ribosome recruitment. While tightly regulated under normal conditions, aberrant overexpression of eIF4E has been implicated in cancer development and progression. This article explores how eIF4E overexpression leads to neoplastic transformation and its significance in oncology.
Role of eIF4E in Translation and Cell Growth
eIF4E is essential for cap-dependent translation initiation, particularly affecting mRNAs with complex 5’ untranslated regions that encode proteins involved in cell proliferation and survival. By controlling the translation of these “weak” mRNAs, eIF4E acts as a gatekeeper of cellular growth.
eIF4E Overexpression and Oncogenesis
Multiple studies have demonstrated that elevated eIF4E levels:
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Increase translation of oncogenes such as c-Myc, cyclin D1, and others.
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Promote loss of contact inhibition and anchorage-independent growth.
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Enhance cell proliferation and survival.
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Correlate with aggressive tumor phenotypes and poor clinical outcomes.
eIF4E overexpression alone can induce transformation in cell culture and tumor formation in animal models, highlighting its oncogenic potential.
Clinical Implications
Because of its central role in tumor biology, eIF4E is a promising target for cancer therapy. Strategies to inhibit eIF4E function or expression are under investigation to suppress tumor growth and overcome resistance to conventional treatments.
Conclusion
Overexpression of eIF4E leads to neoplastic transformation by selectively enhancing the translation of growth-promoting and survival-related mRNAs. This dysregulation contributes significantly to cancer development and progression, making eIF4E a critical focus of cancer research and therapeutic development.
Key Takeaway:
Transfection-induced overexpression of eIF4E in mammalian cells results in neoplastic transformation, underscoring its role as a potent oncogene.
Answer: (2) neoplastic transformation
