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Updated: Mar 22, 2026

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein
Published on: June 30, 2019
Characterisation of the Phosphatidylinositol 3-Kinase Pathway in Non-Small Cell Lung Cancer Cells Isolated from
Martina Puglisi1, Adam Stewart, Parames Thavasu
1The Institute of Cancer Research, London, UK.
Objectives:
We hypothesised that it was possible to quantify phosphorylation of important nodes in the phosphatidylinositol 3-kinase (PI3K) pathway in cancer cells isolated from pleural effusions of patients with non-small cell lung cancer (NSCLC) and study their correlation to somatic mutations and clinical outcomes.
Materials And Methods:
Cells were immunomagnetically separated from samples of pleural effusion in patients with NSCLC. p-AKT, p-S6K and p-GSK3β levels were quantified by ELISA; targeted next-generation sequencing was used to characterise mutations in 26 genes.
Results:
It was possible to quantify phosphoproteins in cells isolated from 38/43 pleural effusions. There was a significant correlation between p-AKT and p-S6K levels [r = 0.85 (95% confidence interval 0.73-0.92), p < 0.0001], but not p-AKT and p-GSK3β levels [r = 0.19 (95% confidence interval -0.16 to 0.5), p = 0.3]. A wide range of mutations was described and p-S6K was higher in samples that harboured at least one mutation compared to those that did not (p = 0.03). On multivariate analysis, p-S6K levels were significantly associated with poor survival (p < 0.01).
Conclusion:
Our study has shown a correlation between p-AKT levels and p-S6K, but not GSK3β, suggesting differences in regulation of the distal PI3K pathway by AKT. Higher p-S6K levels were associated with adverse survival, making it a critically important target in NSCLC.
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