Akt kinase-interacting protein1, a novel therapeutic target for lung cancer with EGFR-activating and gatekeeper...

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are standard treatments for EGFR-mutant lung cancer.
• Acquired resistance to EGFR-TKIs, often mediated by the T790M gatekeeper mutation, remains a significant clinical challenge.
• EGFR-mutant lung cancer cells exhibit dependence on EGFR/Akt signaling pathways, even after developing resistance.

Purpose of the Study:

• To investigate the role of Akt kinase-interacting protein1 (Aki1) in EGFR-mutant lung cancer, with or without the T790M resistance mutation.
• To evaluate Aki1 as a potential therapeutic target for EGFR-mutant lung cancer, especially in cases of acquired TKI resistance.

Main Methods:

• Cell line-based assays were used to examine Aki1's association with mutant EGFR in various lung cancer cell lines.
• Small interfering RNA (siRNA) was employed to silence Aki1 expression in vitro and in a xenograft mouse model.
• The impact of Aki1 silencing on cancer cell apoptosis, tumor growth, and sensitivity to EGFR-TKIs was assessed.

Main Results:

• Aki1 was found to constitutively associate with mutant EGFR in lung cancer cells, irrespective of the T790M mutation status.
• Silencing Aki1 induced apoptosis in EGFR-mutant lung cancer cells and significantly inhibited tumor growth in vivo.
• Aki1 inhibition enhanced the efficacy of novel EGFR-TKIs against resistant H1975 lung cancer cells.

Conclusions:

• Aki1 is frequently expressed in EGFR-mutant lung cancer patients, including those with acquired TKI resistance.
• Aki1 acts as a key mediator of survival signaling from mutant EGFR to Akt.
• Aki1 represents a promising therapeutic target for EGFR-mutant lung cancer, particularly for patients with T790M-mediated acquired resistance.