Decreased eIF3e/Int6 expression causes epithelial-to-mesenchymal transition in breast epithelial cells

Area of Science:

• Molecular Biology
• Cancer Research
• Cell Biology

Background:

• eIF3e/Int6 is a subunit of the eIF3 complex, crucial for protein synthesis initiation.
• Reduced eIF3e/Int6 expression is observed in human breast cancers, with prior studies suggesting both tumor suppressor and oncogenic roles.
• The precise function of eIF3e/Int6 in breast cancer progression, particularly in metastasis, remains unclear.

Purpose of the Study:

• To investigate the role of eIF3e/Int6 in breast cancer by examining the effects of its decreased expression in immortalized breast epithelial cells (MCF-10A).
• To determine if eIF3e/Int6 influences epithelial-to-mesenchymal transition (EMT), a process critical for cancer cell invasion and metastasis.

Main Methods:

• Utilized an immortalized breast epithelial cell line (MCF-10A) to study the impact of reduced eIF3e/Int6 expression.
• Assessed changes in cell morphology, migratory, and invasive properties following eIF3e/Int6 downregulation.
• Quantified the expression levels of key EMT regulators, Snail1 and Zeb2, at both transcriptional and post-transcriptional levels.

Main Results:

• Decreased eIF3e/Int6 expression induced epithelial-to-mesenchymal transition (EMT) in breast epithelial cells.
• EMT triggered by reduced eIF3e/Int6 imparted invasive and migratory capabilities to the cells.
• Reduced eIF3e/Int6 led to increased expression of EMT regulators Snail1 and Zeb2 at both transcriptional and post-transcriptional levels.

Conclusions:

• eIF3e/Int6 plays a novel role in regulating EMT in breast epithelial cells.
• The regulation of EMT by eIF3e/Int6 is implicated in breast cancer metastasis.
• The findings support a tumor suppressor role for eIF3e/Int6 in breast cancer.