EIF3H interacts with PDCD4 enhancing lung adenocarcinoma cell metastasis

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Lung adenocarcinoma (LUAD) is a prevalent cancer with high metastatic potential.
• Programmed cell death factor 4 (PDCD4) is a known tumor suppressor in LUAD, but its regulatory mechanisms are not fully understood.

Purpose of the Study:

• To investigate the regulatory relationship between PDCD4 and eukaryotic translation initiation factor 3 subunit H (EIF3H) in LUAD.
• To elucidate the role of EIF3H in LUAD progression and its interaction with PDCD4.

Main Methods:

• Co-immunoprecipitation assays, mass spectrometry, and immunofluorescent co-localization to confirm PDCD4-EIF3H interaction.
• Overexpression and knockdown studies (siRNA) in LUAD cells to assess functional impacts.
• Analysis of EIF3H and PDCD4 expression in LUAD tissues versus normal tissues.
• In vitro cell migration/invasion assays and in vivo metastasis models in nude mice.

Main Results:

• PDCD4 directly interacts with EIF3H and suppresses EIF3H transcription, reducing its mRNA and protein levels.
• EIF3H is upregulated in LUAD tissues and promotes cell migration, invasion, and metastasis by activating epithelial-mesenchymal transition (EMT) signaling.
• PDCD4 overexpression abrogates EIF3H's oncogenic functions by downregulating EMT signaling.

Conclusions:

• This study reveals a novel inverse regulatory relationship where PDCD4 negatively regulates EIF3H in LUAD.
• EIF3H acts as an oncogenic factor in LUAD by promoting EMT, and its oncogenic activity is counteracted by PDCD4.