Modeling HER2 effects on cell behavior from mass spectrometry phosphotyrosine data

Area of Science:

• Cellular biology
• Systems biology
• Biochemistry

Background:

• Cellular behavior is controlled by intracellular signaling networks.
• Understanding phenotype requires correlating signaling processes with cell function.
• Previous work quantified tyrosine phosphorylation dynamics in human mammary epithelial cells with varying human epidermal growth factor receptor 2 (HER2) expression.

Purpose of the Study:

• To identify signaling mechanisms underlying HER2-mediated cell migration and proliferation.
• To characterize the role of tyrosine phosphorylation in HER2 signaling.
• To develop a predictive model of cell behavior based on signaling states.

Main Methods:

• Quantitative mass spectrometry to measure tyrosine phosphorylation dynamics.
• Partial least squares regression (PLSR) for computational linear mapping.
• Measurement of cell migration and proliferation as functional outputs.

Main Results:

• PLSR identified key phosphotyrosine signals associated with migration and proliferation.
• A "network gauge" of nine informative phosphorylation sites was identified.
• This gauge accurately predicted cell migration and proliferation across different HER2 expression levels and ligand treatments.
• Endocytosis and phosphoinositide 3-kinase (PI3K) pathways were highlighted as critical integration points.

Conclusions:

• A PLSR modeling approach effectively reveals critical signaling processes regulating HER2-mediated cell behavior.
• The identified "network gauge" provides a powerful tool for predicting cell migration and proliferation.
• Specific signaling nodes, including endocytosis and PI3K pathways, are crucial for integrating HER2-driven cellular responses.