Reagent for measuring tyrosine kinase activity, and use thereof

A method for evaluating sensitivity of a lung cancer cell to a tyrosine kinase inhibitor, comprising:

• contacting a modified polypeptide with epidermal growth factor receptor (EGFR) of the lung cancer cell in the presence of the tyrosine kinase inhibitor,
• wherein the modified polypeptide comprises a donor and an acceptor that induce Förster resonance energy transfer bound to CrkL, a CrkL fragment having an SH2 domain and a portion subjected to phosphorylation by a tyrosine kinase, or a CrkL variant consisting of an amino acid sequence having an identity of 90% or more with the amino acid sequence of CrkL or the CrkL fragment and acting as a substrate for a tyrosine kinase;
• detecting fluorescence from the modified polypeptide;
• and
• evaluating sensitivity to the tyrosine kinase inhibitor based on the fluorescence.

A method for preparing a tyrosine kinase inhibitor-resistant lung cancer cell, comprising:

• contacting a modified polypeptide with EGFR of the lung cancer cell in the presence of the tyrosine kinase inhibitor,
• wherein the modified polypeptide comprises a donor and an acceptor that induce Förster resonance energy transfer bound to CrkL, a CrkL fragment having an SH2 domain and a portion subjected to phosphorylation by a tyrosine kinase, or a CrkL variant consisting of an amino acid sequence having an identity of 90% or more with the amino acid sequence of CrkL or the CrkL fragment and acting as a substrate for a tyrosine kinase:
• detecting fluorescence from the modified polypeptide:
• evaluating sensitivity to the tyrosine kinase inhibitor based on the fluorescence;
• and
• collecting a cell evaluated as being resistant to the tyrosine kinase inhibitor.

A method for measuring a tyrosine kinase activity of EGFR in a lung cancer cell, comprising:

• contacting a modified polypeptide with EGFR of the lung cancer cell,
• wherein the modified polypeptide comprises a donor and an acceptor that induce Förster resonance energy transfer bound to CrkL, a CrkL fragment having an SH2 domain and a portion subjected to phosphorylation by a tyrosine kinase, or a CrkL variant consisting of an amino acid sequence having an identity of 90% or more with the amino acid sequence of CrkL or the CrkL fragment and acting as a substrate for a tyrosine kinase;
• and
• detecting fluorescence from the modified polypeptide.